12 research outputs found
On temporal scale-free non-periodic stimulation and its mechanisms as an infinite improbability drive of the brain’s functional connectogram
Rationalized development of electrical stimulation (ES) therapy is of paramount importance. Not only it will foster new techniques and technologies with increased levels of safety, efficacy, and efficiency, but it will also facilitate the translation from basic research to clinical practice. For such endeavor, design of new technologies must dialogue with state-of-the-art neuroscientific knowledge. By its turn, neuroscience is transitioning—a movement started a couple of decades earlier—into adopting a new conceptual framework for brain architecture, in which time and thus temporal patterns plays a central role in the neuronal representation of sampled data from the world. This article discusses how neuroscience has evolved to understand the importance of brain rhythms in the overall functional architecture of the nervous system and, consequently, that neuromodulation research should embrace this new conceptual framework. Based on such support, we revisit the literature on standard (fixed-frequency pulsatile stimuli) and mostly non-standard patterns of ES to put forward our own rationale on how temporally complex stimulation schemes may impact neuromodulation strategies. We then proceed to present a low frequency, on average (thus low energy), scale-free temporally randomized ES pattern for the treatment of experimental epilepsy, devised by our group and termed NPS (Non-periodic Stimulation). The approach has been shown to have robust anticonvulsant effects in different animal models of acute and chronic seizures (displaying dysfunctional hyperexcitable tissue), while also preserving neural function. In our understanding, accumulated mechanistic evidence suggests such a beneficial mechanism of action may be due to the natural-like characteristic of a scale-free temporal pattern that may robustly compete with aberrant epileptiform activity for the recruitment of neural circuits. Delivering temporally patterned or random stimuli within specific phases of the underlying oscillations (i.e., those involved in the communication within and across brain regions) could both potentiate and disrupt the formation of neuronal assemblies with random probability. The usage of infinite improbability drive here is obviously a reference to the “The Hitchhiker’s Guide to the Galaxy” comedy science fiction classic, written by Douglas Adams. The parallel is that dynamically driving brain functional connectogram, through neuromodulation, in a manner that would not favor any specific neuronal assembly and/or circuit, could re-stabilize a system that is transitioning to fall under the control of a single attractor. We conclude by discussing future avenues of investigation and their potentially disruptive impact on neurotechnology, with a particular interest in NPS implications in neural plasticity, motor rehabilitation, and its potential for clinical translation
Tomando partido: um caso de influência de ideologia política na divulgação da neurociência
A ciência como empreitada humana de busca do conhecimento muito se beneficiou não só do estabelecimento do método científico, mas também de sua divulgação para os pares e para o público leigo. No fazer científico, portanto, entra em cena uma série de atores para além do cientista, incluindo o jornalista e outros mais, estando todos eles sujeitos a imprimir, nesse processo, cores de ideologias de toda natureza, inclusive político-partidária. Apesar de que a quantidade e a qualidade dessa influência é discutível, conhecer o fenômeno parece essencial. Neste artigo de opinião, apresentamos os elementos básicos do método científico e da divulgação científica, bem como as relações que política e ciência mantêm, com interesse especial para aquelas que se dão na divulgação científica para o público leigo. Para isso, analisamos com mais detalhes um caso ilustrativo de influência de ideologia político-partidária na divulgação leiga da neurociência: a repercussão na mídia eletrônica da demonstração do exoesqueleto robótico na abertura da Copa do Mundo no Brasil. Concluímos com reflexões sociológicas que situam a questão em análise em uma perspectiva que talvez coopere na importante aproximação entre ciência e jornalismoScience as a human enterprise of search for knowledge has largely benefited not only from the development of the scientific method, but also from the practice of technical and lay reporting of its findings. In view of this, doing science in society is an activity that relates to a myriad of actors besides the scientist and in which journalists and others are included. Therefore, all these actors may leave a mark in the scientific process as a whole, according to adopted ideologies of many kinds, including political and partisan. Although the quantity and quality of such influences in science are still a matter of debate, getting to know them seems to be of undisputable importance. In this opinion paper, we present the fundamental topics about the scientific method and scientific reporting, as well as the relationships science holds with politics, with a special interest on those concerning scientific reporting to the lay public. For this, we proceed with a more thoughtful analysis of a representative case illustrating the influence of political-partisan ideology in the reporting of neuroscience findings: the electronic media coverage following the demonstration of the robotic exoskeleton during the opening of World Soccer Cup in Brazil. We conclude by revisiting discussions in the literature to put the issue into a proper perspective that may help in the important dialogue between science and journalis
Open-source hardware as a model of technological innovation and academic entrepreneurship The Brazilian landscape
Purpose – The purpose of this paper is to argue in favor of the open hardware philosophy (open-source hardware – OSH) as a technological innovation and academic entrepreneurshipmodel in Brazil. Design/methodology/approach – This argument is based on three pillars. The first one refers to a bibliographic review of theoretical frameworks related to academic entrepreneurship and technological innovation to emphasize the disruptive innovation capacity of academia. Second, a few elements related to the Brazilian political, economic and structural scenario, which entail a (more) favorable environment to technological innovation and academic entrepreneurship, is presented. Finally, concepts related to OSH and its business model are approached to demonstrate the facilitating effect toward the whole process. Findings – As a result of the argument made herein, it is possible to perceive the viability of the OSH model in terms of entrepreneurship and technological innovation in the academic sphere, and to perceive its benefits before social and economic needs in areas such as health and education. Research limitations/implications – There are no empirical or quantifiable data in the literature that enable comparison between OSH and traditional technological innovation models. Originality/value – The considerations on the philosophical value of OSH and its business models are scarcely explored in international literature. As far as we know, relating OSH to technological innovation entrepreneurship in the academic sphere, as well as its singularities in Brazil regarding the innovation national system and social and economic demands, is a unique approach in literature
Anatomically dependent anticonvulsant properties of temporally-coded electrical stimulation
AbstractIn the PTZ animal model of epilepsy, electrical stimulation applied to the amygdaloid complex may result in either pro-convulsive or anticonvulsant effect, depending on the temporal pattern used (i.e. periodic-PS and non-periodic-NPS electrical stimulation). Our hypothesis is that the anatomical target is a determinant factor for the differential effect of temporally-coded patterns on seizure outcome. The threshold dose of PTZ to elicit forelimb clonus and generalized tonic–clonic seizure behavior was measured. The effect of amygdaloid complex PS on forelimb clonus threshold showed a pro-convulsive effect while NPS was anticonvulsant. NPS also significantly increased generalized tonic–clonic threshold; while PS, although at lower threshold levels, did not present statistical significance. Thalamus stimulation did not affect forelimb clonus threshold and showed similar anticonvulsant profiles for both PS and NPS on generalized tonic–clonic threshold. In summary, the anatomical target is a determinant factor on whether temporally-coded ES differentially modulates seizure outcome
Personalized strategies of neurostimulation: from static biomarkers to dynamic closed-loop assessment of neural function
Despite considerable advancement of first choice treatment (pharmacological, physical therapy, etc.) over many decades, neurological disorders still represent a major portion of the worldwide disease burden. Particularly concerning, the trend is that this scenario will worsen given an ever expanding and aging population. The many different methods of brain stimulation (electrical, magnetic, etc.) are, on the other hand, one of the most promising alternatives to mitigate the suffering of patients and families when conventional treatment fall short of delivering efficacious treatment. With applications in virtually all neurological conditions, neurostimulation has seen considerable success in providing relief of symptoms. On the other hand, a large variability of therapeutic outcomes has also been observed, particularly in the usage of non-invasive brain stimulation (NIBS) modalities. Borrowing inspiration and concepts from its pharmacological counterpart and empowered by unprecedented neurotechnological advancement, the neurostimulation field has seen in recent years a widespread of methods aimed at the personalization of its parameters, based on biomarkers of the individuals being treated. The rationale is that, by taking into account important factors influencing the outcome, personalized stimulation can yield a much-improved therapy. Here, we review the literature to delineate the state-of-the-art of personalized stimulation, while also considering the important aspects of the type of informing parameter (anatomy, function, hybrid), invasiveness, and level of development (pre-clinical experimentation versus clinical trials). Moreover, by reviewing relevant literature on closed loop neuroengineering solutions in general and on activity dependent stimulation method in particular, we put forward the idea that improved personalization may be achieved when the method is able to track in real time brain dynamics and adjust its stimulation parameters accordingly. We conclude that such approaches have great potential of promoting the recovery of lost functions and enhance the quality of life for patients
Synthesis and application of sugarcane bagasse cellulose mixed esters. Part I: Removal of Co2+ and Ni2+ from single spiked aqueous solutions in batch mode using sugarcane bagasse cellulose succinate phthalate
Sugarcane bagasse cellulose mixed ester succinate phthalate (SBSPh) was synthesized by a novel one-pot reaction method. The effects of temperature, time and mole fraction of succinic anhydride (χSA) on the responses weight gain (wg), number of carboxylic acid groups (nT,COOH), and adsorption capacity (q) of Co2+ and Ni2+ were evaluated by a 23 experimental design. The chemical structure of the material was elucidated by Fourier transform infrared, 13C Multiple Cross-Polarization solid-state NMR spectroscopy and 1H NMR relaxometry. The best SBSPh synthesis condition (100 °C, 11 h, χSA of 0.2) yielded a wg of 59.1%, nT,COOH of 3.41 mmol g−1, and values of qCo2+ and qNi2+ of 0.348 and 0.346 mmol g−1, respectively. The Sips model fitted better the equilibrium data, and the maximum adsorption capacities (pH 5.75 and 25 °C) estimated by this model were 0.62 and 0.53 mmol g−1 for Co2+ and Ni2+, respectively. The ΔadsH° values estimated by isothermal titration calorimetry were 8.43 and 7.79 kJ mol−1 for Co2+ and Ni2+, respectively. Desorption and re-adsorption efficiencies were evaluated by a 22 experimental design, which showed that SBSPh adsorbent can be recovered and reused without significant loss of adsorption capacity
Distinct temporal patterns of electrical stimulation influence neural recruitment during PTZ infusion: An fMRI study
Nonperiodic stimulation for the treatment of refractory epilepsy: Applications, mechanisms, and novel insights
Brazilian Flora 2020: Leveraging the power of a collaborative scientific network
International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora