Quantitative Kinematic Characterization of Reaching Impairments in Mice After a Stroke

Background and Objective. Kinematic analysis of reaching movements is increasingly used to evaluate upper extremity function after cerebrovascular insults in humans and has also been applied to rodent models. Such analyses can require time-consuming frame-by-frame inspections and are affected by the experimenter's bias. In this study, we introduce a semi-automated algorithm for tracking forepaw movements in mice. This methodology allows us to calculate several kinematic measures for the quantitative assessment of performance in a skilled reaching task before and after a focal cortical stroke. Methods. Mice were trained to reach for food pellets with their preferred paw until asymptotic performance was achieved. Photothrombosis was then applied to induce a focal ischemic injury in the motor cortex, contralateral to the trained limb. Mice were tested again once a week for 30 days. A high frame rate camera was used to record the movements of the paw, which was painted with a nontoxic dye. An algorithm was then applied off-line to track the trajectories and to compute kinematic measures for motor performance evaluation. Results. The tracking algorithm proved to be fast, accurate, and robust. A number of kinematic measures were identified as sensitive indicators of poststroke modifications. Based on end-point measures, ischemic mice appeared to improve their motor performance after 2 weeks. However, kinematic analysis revealed the persistence of specific trajectory adjustments up to 30 days poststroke, indicating the use of compensatory strategies. Conclusions. These results support the use of kinematic analysis in mice as a tool for both detection of poststroke functional impairments and tracking of motor improvements following rehabilitation. Similar studies could be performed in parallel with human studies to exploit the translational value of this skilled reaching analysis

Eksistensi Kawasan Pasar Telo Karangkajen (Ptk) dan Penghidupan Masyarakat Pedagang Ketela di YOGYAKARTA

Penelitian ini bertujuan mendiskripsikan profil Pasar Telo Karangkajen, mengkaji persepsi stakeholder terhadap keberlanjutan eksistensi PTK, dan mengetahui strategi penghidupan pedagang ketela di PTK. Metode ini menggunakan metode sensus untuk informan utama dan snowballing sampling untuk informan tambahan. Data digunakan dengan wawancara mendalam dan mengumpulkan studi literatur. Hasil dari penelitian ini menunjukkan PTK mulai berdiri semenjak tahun 1957 yang dirintis oleh pedagang ketela pindahan dari Pasar Ngasem. Tidak sembarangan orang bisa masuk, karena bisnis ketela merupakan lingkup bisnis keluarga. Selama ini PTK dapat menutupi kebutuhan masyarakat di DIY dan untuk memenuhinya, didatangkan dagangan dari daerah lokal dan Jawa Tengah. Kondisi sarana prasarana bagi PTK tidak banyak disediakan oleh pemkot, sebagian besar adalah hasil dari kerja mandiri pedagang melalui kegiatan paguyuban. Eksistensi dari keberadaan PTK stagnan, tidak mungkin dihilangkan atau dikembangkan. Strategi penghidupan yang dilakukan pedagang ketela adalah berjualan ketela, hasil dari berbisnis ketela tersebut telah meningkatkan aset rumahtangganya, sehingga kebutuhannya terpenuhi

Simulating Influenza Epidemics with Waning Vaccine Immunity

In this study, we simulate an influenza epidemic that considers the effects of waning immunity by fitting epidemiological models to CDC secondary historical data aggregated on a weekly basis, and derive the transmission rates at which susceptible individuals become infected over the course of the influenza season. Using a system of differential equations, we define four groups of individuals in a population: susceptible, vaccinated, infected, and recovered. We show that a larger number of initially infected individuals might not only bring the influenza season to an end sooner but also reduce the epidemic size. Moreover, any influenza virus that entails a faster recovery rate does not necessarily lead to a smaller epidemic size

Neuroplastic Changes Following Brain Ischemia and their Contribution to Stroke Recovery: Novel Approaches in Neurorehabilitation

Ischemic damage to the brain triggers substantial reorganization of spared areas and pathways, which is associated with limited, spontaneous restoration of function. A better understanding of this plastic remodeling is crucial to develop more effective strategies for stroke rehabilitation. In this review article, we discuss advances in the comprehension of post-stroke network reorganization in patients and animal models. We first focus on rodent studies that have shed light on the mechanisms underlying neuronal remodeling in the perilesional area and contralesional hemisphere after motor cortex infarcts. Analysis of electrophysiological data has demonstrated brain-wide alterations in functional connectivity in both hemispheres, well beyond the infarcted area. We then illustrate the potential use of non-invasive brain stimulation (NIBS) techniques to boost recovery. We finally discuss rehabilitative protocols based on robotic devices as a tool to promote endogenous plasticity and functional restoration

Impact of channelized flow on temperature distribution and fluid flow in restless calderas:Insight from Campi Flegrei caldera, Italy

Magmatic hydrothermal systems develop by the imposition of a magmatically derived heat flux upon a shallow groundwater system. As such their dynamics can be intermittently perturbed by changing conditions within the associated magmatic system. Understanding the nature of the coupling between the magmatic and groundwater systems is thus key to discriminating geophysical signals of magmatic unrest from purely hydrothermal ones.Using a series of numerical groundwater models run with TOUGH2, we simulate the coupled groundwater–magmatic system at Campi Flegrei caldera, with particular emphasis on the impact of permeability developed within local fault systems and the dynamics of the system during magmatic unrest. Simulation results suggest that faults can play an important role in controlling the dynamics of recharge and heat transport within the shallow hydrothermal reservoir. Results specifically highlight that contrasts in permeability between faults and surrounding rock impact local temperature gradients, with faults either acting as preferential routes for recharge or discharge of groundwater, depending on fault/caldera fill permeability contrast and the vertical extent of the fault. Simulations of magmatic unrest with a step-wise increase in basal heat flux suggest that periodic geophysical and chemical signals may stem from the interaction between the development of gas at depth and the recharge–discharge dynamics of the reservoir. These results highlight the potential for the dynamics of magmatic–hydrothermal systems to be significantly impacted by the presence and nature of local fault systems. Where dynamic groundwater systems are involved, it is thus important to understand the impact of such geological elements when interpreting monitoring data such as ground deformation, seismicity and gas emissions

Diversidad genética de Pinus pinaster en la Península Ibérica: correlación entre isoenzimas y caracteres cuantitativos

The estimation of genetic diversity using molecular markers is a major component of genetic conservation programs. However, molecular data are only weakly correlated with adaptive variation, which seriously limits the value of molecular information for guiding conservation policies. In this paper, we used allozyme markers to analyse the distribution of gene diversity in the native range of Pinus pinaster Ait. in the Iberian Peninsula, including seven marginal populations close to the Mediterranean Basin. Then, the variability of three quantitative traits (total height, stem form and survival) was computed using data from a multisite provenance test in central Spain and the two data sets were compared. Within the general pattern of variation, marginal populations presented levels of diversity closely related to those of nearby central populations, clearly suggesting that historical factors were more important than actual population sizes in determining levels of observed diversity. A weak but nevertheless significant correlation between allozymes and quantitative variability was found in maritime pine. Environmental gradients, as measured by geographic variables, are suggested to have selective effects on quantitative traits and to influence effective population size, which might explain the weak correlation found between allozyme and adaptive variability.Uno de los principales componentes de los programas de conservación genética es el uso de marcadores moleculares para la estimación de la diversidad genética. A pesar de ello, la variación observada en marcadores moleculares está débilmente correlacionada con la variación adaptativa, lo que limita seriamente la aplicación de estos estudios en el desarrollo de políticas de conservación. En este trabajo, se compara la distribución de la diversidad genética de Pinus pinaster Ait. en la Península Ibérica obtenida con marcadores moleculares (isoenzimas) y caracteres cuantitativos (altura, forma del fuste y supervivencia). El estudio incluye siete poblaciones marginales. Éstas, muestran valores de diversidad similares a los de poblaciones centrales próximas lo que sugiere una gran importancia de los procesos históricos regionales frente a efectos relacionados con el tamaño efectivo poblacional. La correlación de los marcadores moleculares utilizados con los caracteres cuantitativos medidos en los ensayos de campo es débil, aunque significativa. Esta correlación podría explicarse considerando efectos selectivos en respuesta a gradientes ambientales que afectan a su vez el tamaño efectivo de las poblaciones