Chronicles of Oklahoma

Article pays a biographical tribute to Alice Brown Davis, school superintendent, court interpreter, and later chief of her tribe, in her dedication and contributions to the Seminole Nation after their relocation to Oklahoma

De moscas a humanos: Genes circadianos en la neurogenética de la adicción

Drug addiction is a persistent brain disease with severe and sometimes fatal consequences. Addictive drugs induce long-lasting neuroadaptations in the functioning of the nervous system and currently there is no efficient pharmacological treatment that can successfully prevent or reverse these changes. As a consequence, addicted individuals often suffer from recurrent relapses, sometimes triggered by environments, situations or stressors that have previously been associated with drug taking.Behavioral neuroscience uses animal models to understand the neurobiological mechanisms which cause and correlate with the development of addiction, and recently the emphasis is on animals that are genetically tractable, such as mice (Mus musculus) and fruit flies, (Drosophila melanogaster). In spite of many obvious differences between humans and Drosophila, similarities at the genetic level and in the basic neuronal physiology, make Drosophila an excellent model organism for the study of many complex human behaviors, including addiction. Discovery that circadian genes influence the development of behavioral sensitization to cocaine in Drosophila led to numerous studies about the role of circadian genes in the regulation of drug-induced behaviors in laboratory mammals and humans. Results show that circadian genes are involved in regulating the behavioral and molecular response to different classes of drugs of abuse. Furthermore, studies in humans show the interconnectivity between the regulation of circadian behavior, mental diseases and addiction, and suggest that behavioral interventions aimed at improving the quality of the circadian behavior will be important in prevention and treatment of addictive behaviors.Ovisnost je o drogama kronična bolest s teškim, nerijetko fatalnim posljedicama. Opojne droge izazivaju dugotrajne neuroadaptivne promjene u funkcioniranju živčanog sustava, a ne postoji učinkovit lijek koji bi ih suzbio ili ispravio. Ovisnici stoga pate od opetovanih recidiva, ponekad izazvanih okolinom, situacijom ili stresom koji je i bio povezan s uzimanjem droge.Bihevioralna neuroznanost koristi modelne organizme za razumijevanje neurobioloških mehanizama koji uvjetuju ili koreliraju s razvojem ovisnosti, a odnedavno naglasak je na životinjama koje su genetski pogodne, kao miš (Mus musculus) ili vinska mušica (Drosophila melanogaster). Unatoč mnogim očitim razlikama između ljudi i Drosophile sličnosti na genetskoj razini i u području bazične neuronske fiziologije čine Drosophilu izvrsnim modelnim organizmom za izučavanje mnogih složenih ljudskih ponašanja, uključujući ovisnost. Otkriće da cirkadijalni geni kontroliraju razvoj bihevioralne senzitizacije na kokain kod Drosophile potaklo je niz istraživanja o ulozi koju cirkadijalni geni imaju u ponašanjima induciranim kokainom kod laboratorijskih životinja i ljudi. Rezultati pokazuju da cirkadijalni geni reguliraju ponašanja i molekularne odgovore na razne vrste opojnih droga. Štoviše, istraživanja na ljudima upućuju na međupovezanost između cirkadijalnog ponašanja, mentalnih oboljenja i ovisnosti, te sugeriraju da bihevioralni zahvati usmjereni na poboljšanje cirkadijalnog ponašanja mogu biti važni u prevenciji i liječenju ovisničkog ponašanja.La drogadicción es una de las enfermedades crónicas con consecuencias graves, a veces fatales. Las drogas adictivas causan cambios neuroadaptivos a largo plazo en el funcionamiento del sistema nervioso y de momento no existe un medicamento eficiente que lo reprimiría o corregiría. Por eso los drogadictos sufren repetidas recaídas, a veces causadas por el entorno, situación o estrés previamente relacionado con el consumo de drogas.Neurociencia conductual usa organismos modelos para comprender mecanismos neurobiológicos que condicionan o se correlacionan con el desarrollo de la adicción, y recientemente el enfoque está en los animales genéticamente convenientes, como ratón (Musmusculus) o mosca del vinagre (Drosophila melanogaster). A pesar de las numerosas diferencias obvias entre los humanos y las moscas del vinagre, la semejanza al nivel genético y aquel de fisiología neuronal básica convierten dicha mosca del vinagre en un excelente organismo modelo para estudiar muchas conductas humanas complejas, incluida la adicción. Al descubrir que los genes circadianos controlan el desarrollo de la sensibilización de comportamiento de la mosca del vinagre en cuanto a la cocaína, se provocó toda una serie de investigaciones sobre el papel que tienen los genes circadianos para los comportamientos inducidos por la cocaína tanto en los animales de laboratorio, como en los humanos. Los resultados indican que los genes circadianos regulan comportamientos y respuestas moleculares a diferentes tipos de drogas adictivas. Es más, las investigaciones en los humanos muestran la interconexión entre el comportamiento circadiano, enfermedades mentales y adicción, y proponen que las intervenciones en el comportamiento enfocadas en la mejora del comportamiento circadiano pueden ser importantes en la prevención y tratamiento de conductas adictivas

Estimating Groundwater Recharge in Fully Integrated pde-Based Hydrological Models

Groundwater recharge is the main forcing of regional groundwater flow. In traditional partial-differential-equation (pde)-based models that treat aquifers as separate compartments, groundwater recharge needs to be defined as a boundary condition or it is a coupling condition to other compartments. Integrated models that treat the vadose and phreatic zones as a continuum allow for a more sophisticated calculation of subsurface fluxes, as feedbacks between both zones are captured. However, they do not contain an explicit groundwater-recharge term so it needs to be estimated by post-processing. Groundwater recharge consists of changes in groundwater storage and of the flux crossing the water table, which can be calculated based on hydraulic gradients. We introduce a method to evaluate the change of groundwater storage by a time-cumulative water balance over the depth section of water table fluctuations, avoiding the use of a specific yield. We demonstrate the approach first by a simple 1-D vertical model that does not allow for lateral outflow and illustrates the ambiguity of computing groundwater recharge by different methods. We then apply the approach to a 3-D model with a complex topography and subsurface structure. The latter example shows that groundwater recharge is highly variable in space and time with notable differences between regional and local estimates. Local heterogeneity of topography or subsurface properties results in complex redistribution patterns of groundwater. In fully integrated models, river-groundwater exchange flow may severely bias the estimate of groundwater recharge. We, therefore, advise masking out groundwater recharge at river locations

Simulation and experimental study of methane-propane hydrate dissociation by high pressure differential scanning calorimetry

Binary and ternary systems composed of methane-water and methane-propane-water, respectively, were studied using high pressure differential scanning calorimetry. The methodology was validated by comparing results for the binary system to experimental data obtained in the literature. The hydrate dissociation temperatures for the ternary system (methane-propane-water) at 21 MPa were experimentally determined for different compositions of the gas mixture and mole fractions of propane higher than 0.1 in the ternary system. Our results are in good agreement with the values predicted by applying the Cubic Plus Association (CPA) equation of state coupled with van der Waals-Platteeuw model for the hydrate phase. Although experimental results are considered satisfactory for both binary and ternary systems, higher deviations between our values and the simulated ones for the ternary system, considering peak temperature instead of the extrapolated onset as the hydrate dissociation temperature, are believed to be a consequence of dynamic effects that promote the formation of a heterogeneous hydrate and are negligible for the binary system352403414CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP132505/20152014/02140-7; 2014/25740-0; 2015/23148-

The cientificWorldJOURNAL Research Article Effect of Low-Frequency Repetitive Transcranial Magnetic Stimulation on Naming Abilities in Early-Stroke Aphasic Patients: A Prospective, Randomized, Double-Blind Sham-Controlled Study

Background and Purpose. Functional brain imaging studies with aphasia patients have shown increased cortical activation in the right hemisphere language homologues, which hypothetically may represent a maladaptive strategy that interferes with aphasia recovery. The aim of this study was to investigate whether low-frequency repetitive transcranial magnetic stimulation (rTMS) over the Broca's homologues in combination with speech/language therapy improves naming in early-stroke aphasia patients. Methods. 26 right-handed aphasic patients in the early stage (up to 12 weeks) of a first-ever left hemisphere ischemic stroke were randomized to receive speech and language therapy combined with real or sham rTMS. Prior to each 45-minute therapeutic session (15 sessions, 5 days a week), 30 minutes of 1-Hz rTMS was applied. Outcome measures were obtained at baseline, immediately after 3 weeks of experimental treatment and 15 weeks; posttreatment using the Computerized Picture Naming Test. Results. Although both groups significantly improved their naming abilities after treatment, no significant differences were noted between the rTMS and sham stimulation groups. The additional analyses have revealed that the rTMS subgroup with a lesion including the anterior part of language area showed greater improvement primarily in naming reaction time 15 weeks after completion of the therapeutic treatment. Improvement was also demonstrated in functional communication abilities. Conclusions. Inhibitory rTMS of the unaffected right inferior frontal gyrus area in combination with speech and language therapy cannot be assumed as an effective method for all poststroke aphasia patients. The treatment seems to be beneficial for patients with frontal language area damage, mostly in the distant time after finishing rTMS procedure

Computational models and motor learning paradigms: Could they provide insights for neuroplasticity after stroke? An overview

Computational approaches for modelling the central nervous system (CNS) aim to develop theories on processes occurring in the brain that allow the transformation of all information needed for the execution of motor acts. Computational models have been proposed in several fields, to interpret not only the CNS functioning, but also its efferent behaviour. Computational model theories can provide insights into neuromuscular and brain function allowing us to reach a deeper understanding of neuroplasticity. Neuroplasticity is the process occurring in the CNS that is able to permanently change both structure and function due to interaction with the external environment. To understand such a complex process several paradigms related to motor learning and computational modeling have been put forward. These paradigms have been explained through several internal model concepts, and supported by neurophysiological and neuroimaging studies. Therefore, it has been possible to make theories about the basis of different learning paradigms according to known computational models. Here we review the computational models and motor learning paradigms used to describe the CNS and neuromuscular functions, as well as their role in the recovery process. These theories have the potential to provide a way to rigorously explain all the potential of CNS learning, providing a basis for future clinical studies

Excitatory repetitive Transcranial Magnetic Stimulation applied to the right inferior frontal gyrus has no effect on motor or cognitive impulsivity in healthy adults

Background: Impulsivity is a multi-faceted concept. It is a crucial feature of many neuropsychiatric disorders. Three subtypes of impulsivity have been identified: motor, temporal, and cognitive impulsivity. Existing evidence suggests that the right inferior frontal gyrus (rIFG) plays a crucial role in impulsivity, and such a role has been elucidated using inhibitory repetitive transcranial magnetic stimulation (rTMS). There is a dearth of studies using excitatory rTMS at the rIFG, an important gap in the literature this study aimed to address. Methods: Twenty healthy male adults completed a single-blind sham-controlled randomised crossover study aimed at assessing the efficacy of rTMS in the neuromodulation of impulsivity. This involved delivering 10-Hz excitatory rTMS to the rIFG at the intensity of 100% motor threshold with 900 pulses per session. Trait impulsivity was measured at baseline using the Barrett Impulsiveness Scale and UPPS-P Impulsiveness Scale. The Stop Signal Task (SST) and Information Sampling Task (IST), administered before andafter rTMS sessions, were used as behavioural measures of impulsivity. Results: No significant changes on any measures from either SST or IST after active rTMS at the rIFG compared to the sham-controlled condition were found. Conclusions: Excitatory rTMS applied to the rIFG did not have a statistically significant effect on response inhibition and reflective/cognitive impulsivity. Further research is required before drawing firm conclusions. This may involve a larger sample of highly impulsive individuals, a different stimulation site or a different TMS modality such as theta burst stimulation