Evaluation of the effect of training using auditory stimulation on rhythmic movement in Parkinsonian patients—a combined motor and [18F]-FDG PET study

[Abstract] Introduction: A programme of rehabilitation using auditory cues has previously been shown to decrease movement variability in the gait of Parkinsonian patients. Objective and methods: We studied the temporal variability of finger-tapping and gait in 9 patients with Parkinson's disease (PD) before and after they undertook a physical rehabilitation programme. Positron Emission Tomography (PET) using 2-deoxy-2[18F]fluoro-d-glucose (FDG) was performed in these subjects to look for changes in metabolic brain activity after completion of the rehabilitation program. Results: The reduction of variability was seen not only in gait but also other repetitive movements such as finger tapping. Furthermore, here we show differences in resting regional cerebral glucose utilisation in these patients compared to healthy controls (significant hypometabolism—p<0.001—for the PD group in the right parietal and temporal lobes, left temporal and frontal lobes and a hypermetabolism in the left cerebellum) and specific changes following the improvements in repetitive movement abilities (significant metabolic increment—p<0.001—in the PD group in the right cerebellum and in the right parietal and temporal lobes). Conclusions: Although our study does not allow us to draw firm conclusions, it provides new information on the neural basis of auditory stimulation in PD. Our results extend those from previous studies to show improvement in the temporal variability of two types of rhythmic movements after participation by PD patients in a physical rehabilitation programme, along with changes in glucose uptake in several brain areas involved in sensorimotor processing.Xunta de Galicia; PGIDIT02BTF13701P

Biology and new records of the invasive species Branchiomma bairdi (Annelida: Sabellidae) in the Mediterranean Sea

First observations on the reproductive biology of the alien polychaete Branchiomma bairdi (McIntosh, 1885) (Sabellidae) in the Mediterranean Sea are provided as well as additional Mediterranean records of the species which can help to understand its introduction and spreading. Re-examination of the specimens from Miseno harbour (Tyrrhenian Sea, Italy) revealed the presence of B. bairdi in the central-Mediterranean since September 2004. The histological study of individuals collected in Malta revealed that the species is a simultaneous hermaphrodite, developing male and female gametes in the same body segments; embryos are brooded inside the parent tube. However, there is evidence also for asexual reproduction. The species shows a different reproductive pattern from the previously reported population from the eastern-Pacific; this demonstrates its great plasticity and adaptability. Branchiomma bairdi has an invasive behaviour, colonizing large areas in relatively short-time, and reaching relatively high densities (c.a. 50 individuals/m2). Its expansion throughout several Mediterranean localities is largely a consequence of the high capacity of this species to colonize extremely different habitats and substrates, to the occurrence of sexual and asexual reproductive strategies, and the combination of both. Further, B. bairdi appears to be particularly abundant in confined and anthropogenic degraded areas. Finally, our findings strongly suggest that the pathway of introduction in the Mediterranean, previously hypothesized as the Suez Canal (Lessepsian migration), is most likely via the Gibraltar Strait

Ab initio and finite-temperature molecular dynamics studies of lattice resistance in tantalum

This manuscript explores the apparent discrepancy between experimental data and theoretical calculations of the lattice resistance of bcc tantalum. We present the first results for the temperature dependence of the Peierls stress in this system and the first ab initio calculation of the zero-temperature Peierls stress to employ periodic boundary conditions, which are those best suited to the study of metallic systems at the electron-structure level. Our ab initio value for the Peierls stress is over five times larger than current extrapolations of experimental lattice resistance to zero-temperature. Although we do find that the common techniques for such extrapolation indeed tend to underestimate the zero-temperature limit, the amount of the underestimation which we observe is only 10-20%, leaving open the possibility that mechanisms other than the simple Peierls stress are important in controlling the process of low temperature slip.Comment: 12 pages and 9 figure

Caracterización conductual y neuroinmune de la resiliencia al estrés social: Efectos reforzantes de la cocaína

Numerosos estudios preclínicos han demostrado que el estrés social incrementa la vulnerabilidad a los efectos reforzantes de la cocaína. Sin embargo, los resultados obtenidos no son homogéneos, observándose siempre una subpoblación que no muestra dicho incremento. Utilizando el modelo de derrota social (DS) repetida en ratones, en este trabajo hemos querido caracterizar conductualmente a los ratones resilientes al incremento de los efectos reforzantes de la cocaína inducido por el estrés social. Utilizamos ratones adultos macho de la cepa C57/BL6 a los que sometimos al protocolo de DS repetida y tres semanas más tarde, realizamos el Condicionamiento de Preferencia de Lugar (CPL) inducido por una dosis no efectiva de cocaína (1mg/kg). Una vez finalizado este procedimiento se midieron los niveles estriatales de interleucina 6, ya que el estrés social produce una respuesta de neuroinflamación. No se observó CPL en los ratones controles, pero los animales derrotados tomados en conjunto desarrollaron preferencia. Sin embargo, esta muestra se pudo dividir en ratones resilientes (no desarrollaron preferencia) y susceptibles (presentaron CPL). Durante las derrotas sociales, los animales resilientes pasaron menos tiempo en las conductas de huida y sumisión que los catalogados como susceptible y presentaron conductas de ataque hacia el ratón residente, manifestando por tanto resistencia a ser derrotados. No se observaron diferencias en la respuesta de neuroinflamación, probablemente debido al largo periodo de tiempo trascurrido desde la última derrota social. Nuestros resultados sugieren que un estilo de afrontamiento activo al estrés social va a ser determinante en la protección del sujeto a desarrollar un trastorno por uso de drogas. Preclinical studies have shown that social stress increases vulnerability to the reinforcing effects of cocaine. However, the results are not always homogeneous, revealing a subpopulation that does not show a preference for cocaine. Thus, the main aim of the present study was to characterize the behavioral profile of resilient mice to the stress-induced rewarding effects of cocaine using an animal model of repeated social defeat stress (SD). To this end, male adult mice of the C57/BL6 strain were exposed to SD and, three weeks later, assessed using the Conditioned Place Preference paradigm induced by an ineffective dose of cocaine (1mg/kg). Afterwards, the striatal levels of interleukin 6 were measured, as social stress usually induces a neuroinflammatory response. Control mice did not develop CPP, while defeated mice did overall develop a preference for the drug-paired compartment. Based on the conditioning score that they exhibited, the SD sample was subdivided into resilient (did not develop preference) and susceptible mice (developed preference). During the SD sessions, resilient animals showed less flight and submission behaviors than susceptible mice and they presented attack behaviors towards the residents, thereby showing their resistance to being defeated. There were no differences in the neuroinflammatory response, probably due to the long time elapsed after the last SD session. These results suggest that an active coping style to social stress may be decisive in protecting the individual from developing an addiction. © 2021, Edita Socidrogalcohol. All rights reserved

Acceleration Schemes for Ab-Initio Molecular Dynamics and Electronic Structure Calculations

We study the convergence and the stability of fictitious dynamical methods for electrons. First, we show that a particular damped second-order dynamics has a much faster rate of convergence to the ground-state than first-order steepest descent algorithms while retaining their numerical cost per time step. Our damped dynamics has efficiency comparable to that of conjugate gradient methods in typical electronic minimization problems. Then, we analyse the factors that limit the size of the integration time step in approaches based on plane-wave expansions. The maximum allowed time step is dictated by the highest frequency components of the fictitious electronic dynamics. These can result either from the large wavevector components of the kinetic energy or from the small wavevector components of the Coulomb potential giving rise to the so called {\it charge sloshing} problem. We show how to eliminate large wavevector instabilities by adopting a preconditioning scheme that is implemented here for the first-time in the context of Car-Parrinello ab-initio molecular dynamics simulations of the ionic motion. We also show how to solve the charge-sloshing problem when this is present. We substantiate our theoretical analysis with numerical tests on a number of different silicon and carbon systems having both insulating and metallic character.Comment: RevTex, 9 figures available upon request, to appear in Phys. Rev.

Improved tensor-product expansions for the two-particle density matrix

We present a new density-matrix functional within the recently introduced framework for tensor-product expansions of the two-particle density matrix. It performs well both for the homogeneous electron gas as well as atoms. For the homogeneous electron gas, it performs significantly better than all previous density-matrix functionals, becoming very accurate for high densities and outperforming Hartree-Fock at metallic valence electron densities. For isolated atoms and ions, it is on a par with previous density-matrix functionals and generalized gradient approximations to density-functional theory. We also present analytic results for the correlation energy in the low density limit of the free electron gas for a broad class of such functionals.Comment: 4 pages, 2 figure

Effects of levels of self-regulation and regulatory teaching on strategies for coping with academic stress in undergraduate students

The SRL vs. ERL TheoryTM predicts that regulation-related factors in the student and in the context combine to determine the student's levels in emotional variables, stress, and coping strategies. The objective of the present research was to test this prediction in the aspect of coping strategies. Our hypothesis posed that students' level of self-regulation (low-medium-high), in combination with the level of regulation promoted in teaching (low-medium-high), would determine the type of strategies students used to cope with academic stress; the interaction of these levels would focus coping strategies either toward emotions or toward the problem. A total of 944 university students completed validated questionnaires on self-regulation, regulatory teaching, and coping strategies, using an online tool. ANOVAs and MANOVAs (3 1; 3 3; 5 1) were carried out, in a quasi-experimental design by selection. Level of self-regulation and level of regulatory teaching both had a significant effect on the type of coping strategies used. The most important finding was that the combined level of self-regulation and external regulation, on a five-level scale or heuristic, predicted the type of coping strategies that were used. In conclusion, the fact that this combination can predict type of coping strategies used by the student lends empirical support to the initial theory. Implications for the teaching- learning process at university and for students' emotional health are discussed

Evaluación de algunos parámetros reproductivos en cabras criollas

Se estudiaron 14 cabras y 14 cabrillas de genotipo "regional" o criollas, con el objeto de conocer el comportamiento reproductivo en sistemas semi-intensivos y para determinar la influencia del plano nutricional y edad al servicio sobre la fertilidad(F), la prolificidad (P), y el intervalo entre partos (IEP).Los animales se dividieron al azar en dos grupos de 14, con 7 cabras y 7 cabrillas cada uno, conformándose los siguientes tratamientos: AT (cabra adulta testigo):AS (cabra adulta suplementada); JT (cabra joven testigo); JS (cabra jovensuplementada). Todos los individuos estuvieron sobre pastura natural de crecimiento primavero estival. A los animales de los tratamientos AS y JS se les brindó alimentación suplementaria consistente en 800 grs de heno de alfalfa primerafloración y 200 grs de maíz en grano / madre / día, en servicio, al principio y final de la lactancia. Luego de observar el comportamiento reproductivo de machos y hembras durante todo el año , se consideraron los índices de F, P, e IEP.Los resultados demuestran que hubo diferencias estadísticamente significativas(P &lt; 0,05) en los porcentajes de F entre los tratamientos AS y JS con respecto aAT y JT respectivamente. También hubo diferencias significativas (P&lt; 0,05) cuando se analizó la edad combinada con bajos niveles nutricionales sobre la F y P de las cabras y en cambio no se encontraron diferencias significativas (P &gt; 0.05)en IEP entre los distintos tratamientos, ya que la mayoría de las hembras presentaron anestro estacional de primavera. Se concluye que las cabras criollas delcentro de la provincia de Córdoba (Argentina) se comportan como poliéstricas estacionales, resultando la edad y el nivel nutricional factores restrictivos para el logro del potencial reproductivo de las cabras criollas

Management intensity controls soil N2O fluxes in an Afromontane ecosystem

Studies that quantify nitrous oxide (N2O) fluxes from African tropical forests and adjacent managed land uses are scarce. The expansion of smallholder agriculture and commercial agriculture into the Mau forest, the largest montane forest in Kenya, has caused large-scale land use change over the last decades. We measured annual soil N2O fluxes between August 2015 and July 2016 from natural forests and compared them to the N2O fluxes from land either managed by smallholder farmers for grazing and tea production, or commercial tea and eucalyptus plantations (n = 18). Air samples from 5 pooled static chambers were collected between 8:00 am and 11:30 am and used within each plot to calculate the gas flux rates. Annual soil N2O fluxes ranged between 0.2 and 2.9 kg N ha− 1 yr− 1 at smallholder sites and 0.6–1.7 kg N ha− 1 yr− 1 at the commercial agriculture sites, with no difference between land uses (p = 0.98 and p = 0.18, respectively). There was marked variation within land uses and, in particular, within those managed by smallholder farmers where management was also highly variable. Plots receiving fertilizer applications and those with high densities of livestock showed the highest N2O fluxes (1.6 ± 0.3 kg N2O-N ha− 1 yr− 1, n = 7) followed by natural forests (1.1 ± 0.1 kg N2O-N ha− 1 yr− 1, n = 6); although these were not significantly different (p = 0.19). Significantly lower fluxes (0.5 ± 0.1 kg N ha− 1 yr− 1, p < 0.01, n = 5) were found on plots that received little or no inputs. Daily soil N2O flux rates were not correlated with concurrent measurements of water filled pore space (WFPS), soil temperature or inorganic nitrogen (IN) concentrations. However, IN intensity, a measure of exposure of soil microbes (in both time and magnitude) to IN concentrations was strongly correlated with annual soil N2O fluxes

Resiliencia y autorregulación en jóvenes navarros en riesgo de exclusión social que acuden a Programas de Cualificación Profesional Inicial

En la actualidad, son muchos los jóvenes que abandonan el sistema escolar por falta de metas, desinterés en el estudio y, hoy más que nunca, muchos añaden graves problemas sociales y familiares. Desde la legislación española se han establecido diversos programas, como los Programas de Cualificación Profesional Inicial -PCPI- que aportan nuevas oportunidades para que los jóvenes de 15 a 21 años que abandonan la E.S.O puedan seguir estudiando, adquieran el título de la ESO o bien una formación especializada que cuanto menos les facilite la inserción en el actual y arduo mercado laboral. La investigación se divide en dos partes: la primera en la que se señala la fundamentación teórica a través de la explicación de los tres constructos clave: la exclusión social, la resiliencia y la autorregulación. La segunda alberga el método de la investigación en el que se señalan los análisis realizados, los resultados obtenidos, la discusión y conclusiones destacadas. Para obtener dichos resultados seleccionamos una muestra de 365 alumnos de PCPI de 27 centros de Navarra, casi la población total de alumnos que estudiaban en PCPI en Navarra en el año 2011/2012. En este estudio, se persiguen tres objetivos. En primer lugar, describir la percepción de resiliencia y la autorregulación personal de la conducta de los jóvenes anteriormente mencionados. Para ello se han seleccionado algunos de los instrumentos de medida existentes ya en el campo de investigación: un Cuestionario reducido de Autorregulación Personal (SSRQ) de De la Fuente (2004), adaptado de la escala The Short Self-Regulation Questionnaire (Carey, Neal y Collins, 2004) y tres escalas complementarias de resiliencia: la Child and Youth Resilience Measure (CYRM) de Ungar y Liebenberg (2009), la escala SV-RES (Saavedra y Villalta, 2008) y la escala CD-RISC (Connor y Davidson, 2003). En este sentido, se describen los factores con mayor y menor puntuación (media y desviación típica), se aporta evidencia de la influencia de variables personales y contextuales en la resiliencia y la autorregulación de estos jóvenes (análisis no paramétricos U de Mann-Whitney), y se reafirma la relación entre ambos constructos, señalada en la literatura (ANOVA y MANOVA). El segundo objetivo es conocer y profundizar en las propiedades psicométricas de las escalas. Para ello, se realizan análisis estadísticos (correlación, regresión e inferenciales) a través de los cuáles hemos podido aportar datos relevantes acerca de la fiabilidad y validez de los mismos. Finalmente, el tercer objetivo es conocer la percepción que tienen de estos jóvenes sus profesores, para lo que se ha administrado a los docentes, un cuestionario realizado al efecto con el que se ha podido conocer aún más las características de dichos jóvenes. Con todo, la promoción de la resiliencia para la prevención del riesgo, va más allá de los jóvenes descritos ya que consideramos que la fortaleza y el desarrollo potencial de la misma son cruciales para el desarrollo positivo de cualquier persona