Dementia in Latin America : paving the way toward a regional action plan

Across Latin American and Caribbean countries (LACs), the fight against dementia faces pressing challenges, such as heterogeneity, diversity, political instability, and socioeconomic disparities. These can be addressed more effectively in a collaborative setting that fosters open exchange of knowledge. In this work, the Latin American and Caribbean Consortium on Dementia (LAC-CD) proposes an agenda for integration to deliver a Knowledge to Action Framework (KtAF). First, we summarize evidencebased strategies (epidemiology, genetics, biomarkers, clinical trials, nonpharmacological interventions, networking, and translational research) and align them to current global strategies to translate regional knowledge into transformative actions. Then we characterize key sources of complexity (genetic isolates, admixture in populations, environmental factors, and barriers to effective interventions), map them to the above challenges, and provide the basic mosaics of knowledge toward a KtAF. Finally, we describe strategies supporting the knowledge creation stage that underpins the translational impact of KtAF

Robust assessment of EEG connectivity patterns in Mild Cognitive Impairment and Alzheimer's disease

The prevalence of dementia, including Alzheimer's disease (AD), is on the rise globally with screening and intervention of particular importance and benefit to those with limited access to healthcare. Electroencephalogram (EEG) is an inexpensive, scalable, and portable brain imaging technology that could deliver AD screening to those without local tertiary healthcare infrastructure. We study EEG recordings of sporadic mild cognitive impairment (MCI) and prodromal familial, early-onset, AD subjects for the same working memory tasks using high- and low-density EEG, respectively. A challenge in detecting electrophysiological changes with EEG is that noise and volume conduction effects are common and disruptive to functional connectivity analysis. It is known that the imaginary part of coherency (iCOH) can mitigate against volume conduction when generating functional connectivity networks. We aim to expose topological differences in these connectivity networks with a global network measure, eigenvector alignment (EA), that is shown to be robust to targeted alterations in the connectivity network; emulating the erasure of true instantaneous activity (zero or π-phase) by iCOH. The assessment of alignments establishes the relationship between EEG channels from the similarity of their connectivity patterns. Significant alignments, versus random null models, are found to be consistent across frequency ranges (delta, theta, alpha, and beta) for the working memory tasks - aided by the relative consistency of iCOH connectivities - in order to reveal network structure. For high-density EEG recordings, stark differences in the control and sporadic MCI results are observed with the control group demonstrating far more consistent alignments. These differences are also detected by comparing the significant correlation and iCOH connectivities, again in reference to random null models, where only EA suggests a notable difference in network topology when comparing subjects with sporadic MCI and prodromal familial AD. The consistency of alignments, across frequency ranges, provides a measure of confidence in EA's detection of topological structure, an important aspect that marks this approach as a promising direction for developing a reliable test for early onset AD

PRODUTIVIDADE E CARACTERÍSTICAS REPRODUTIVAS DO ARUANÃ, Osteoglossum bicirrhosum (OSTEOGLOSSIFORMES: OSTEOGLOSSIDAE), NO LAGO GRANDE, BACIA DO RIO PUTUMAYO, PERU

Due to the importance of ornamental fishing of silver arowana, as well as, Lago Grande lake as one of the main areas for capturing baby arowanas in Peru, the present study aimed to evaluate the productivity and the biological-reproductive characteristics of the species in the lake, which is located in the lower basin of the Putumayo River and represents an area preferred by fishermen because the important populations of silver arowana inhabiting it. Analysis of population density, biometrics, sexual maturity, spawning, fecundity, sex ratio, water level of the lake and production of baby arowana were made. The study was developed between March and July of 2012 and to implement the activities of the study was important the participation of the Association of Fishermen “Fronteras Vivas”. In general, the population density extrapolated to the lake area was 1.29 fish/ha. Of these, the density of progenitors in the lake was 1.19 fish/ha. Also, male animals had total length, standard length and total weight higher than females and it was observed that the spawning period occurred in synchronization with the start of the growing of the hydrological regime. The average number of oocytes produced by females of silver arowana in the study area was 201 and the sex ratio was equilibrated. Furthermore, the study shows the capacity of production of the lake. In order to this the water lever influenced in the production of baby arowanas. It is important to continue studying the species for regulate the fishing and recover populations.Keywords: baby arowana; production; ornamental trade; length of first sexual maturity; fishing.Devido à importância da pesca ornamental de aruanã, e da lagoa Lago Grande como uma das principais áreas para a captura de alevinos de aruanã no Peru, o presente estudo tive como objetivo avaliar a produtividade e as características reprodutivas na espécie na lagoa, a mesma que está localizada na bacia baixa do Rio Putumayo e representa uma das áreas de pesca preferidas pela importante população de aruanã que a habitam. Foram feitas análises de densidade populacional, biometria, maturidade sexual, desova, fecundidade, proporção sexual, níveis da água na lagoa e sobre a produção de alevinos de aruanã. O estudo foi desenvolvido entre março a julho de 2012 e as atividades foram realizadas em parceria com a Agrupação de Pescadores “Fronteras Vivas”. De modo geral, a densidade populacional extrapolada à área da lagoa foi de 1.29 peixes∕ha. Daqueles, a densidade de progenitores na lagoa foi de 1.19 peixes∕ha. Além disso, os machos tiveram comprimento total e padrão e peso total maior do que as fêmeas, e foi observado que o período de desova ocorreu em sincronia com o início da crescente no nível das águas. A média de oocitos produzidos por fêmeas de aruanã foi de 201 e a proporção sexual foi equilibrada. Assim mesmo, o estudo mostra a capacidade de produção da lago. Nesse sentido, o nível da água influenciou na produção de alevinos de aruanã. É importante continuar os estudos da espécie para regulamentar a pesca e recuperar populações.Palavras-chave: alevinos de aruanã, produção, comércio ornamental, comprimento de primeira maturidade sexual, pesca

Brain information sharing during visual short-term memory binding yields a memory biomarker for familial Alzheimer’s disease

Background: Alzheimer´s disease (AD) as a disconnection syndrome which disrupts both brain information sharing and memory binding functions. The extent to which these two phenotypic expressions share pathophysiological mechanisms remains unknown.Objective: To unveil the electrophysiological correlates of integrative memory impairments in AD towards new memory biomarkers for its prodromal stages.Methods: Patients with 100% risk of familial AD (FAD) and healthy controls underwent assessment with the Visual Short-Term Memory binding test (VSTMBT) while we recorded their EEG. We applied a novel brain connectivity method (Weighted Symbolic Mutual Information) to EEG data.Results: Patients showed significant deficits during the VSTMBT. A reduction of brain connectivity was observed during resting as well as during correct VSTM binding, particularly over frontal and posterior regions. An increase of connectivity was found during VSTM binding performance over central regions. While decreased connectivity was found in cases in more advanced stages of FAD, increased brain connectivity appeared in cases in earlier stages. Such altered patterns of task-related connectivity were found in 89% of the assessed patients.Conclusions: VSTM binding in the prodromal stages of FAD are associated to altered patterns of brain connectivity thus confirming the link between integrative memory deficits and impaired brain information sharing in prodromal FAD. While significant loss of brain connectivity seems to be a feature of the advanced stages of FAD increased brain connectivity characterizes its earlier stages. These findings are discussed in the light of recent proposals about the earliest pathophysiological mechanisms of AD and their clinical expression.Fil: Parra, Mario A.. Heriot-watt University; Reino UnidoFil: Mikulan, Ezequiel Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Trujillo, Natalia. Universidad de Antioquia; ColombiaFil: Sala, Sergio Della. University of Edinburgh; Reino UnidoFil: Lopera, Francisco. Universidad de Antioquia; ColombiaFil: Manes, Facundo Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Starr, John. Alzheimer Scotland Dementia Research Centre And Scottis; Reino UnidoFil: Ibáñez Barassi, Agustín Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; Argentina. Universidad Adolfo Ibañez; Chil

Dementia in Latin America : paving the way towards a regional action plan

Regional challenges faced by Latin American and Caribbean countries (LACs) to fight dementia, such as heterogeneity, diversity, political instabilities, and socioeconomic disparities, can be addressed more effectively grounded in a collaborative setting based on the open exchange of knowledge. In this work, the Latin American and Caribbean Consortium on Dementia (LAC-CD) proposes an agenda for integration to deliver a Knowledge to Action Framework (KtAF). First, we summarize evidence-based strategies (epidemiology, genetics, biomarkers, clinical trials, nonpharmacological interventions, networking and translational research) and align them to current global strategies to translate regional knowledge into actions with transformative power. Then, by characterizing genetic isolates, admixture in populations, environmental factors, and barriers to effective interventions and mapping these to the above challenges, we provide the basic mosaics of knowledge that will pave the way towards a KtAF. We describe strategies supporting the knowledge creation stage that underpins the translational impact of KtAF

Una teoria de inmunizacion de carteras de bonos

Centro de Informacion y Documentacion Cientifica (CINDOC). C/Joaquin Costa, 22. 28002 Madrid. SPAIN / CINDOC - Centro de Informaciòn y Documentaciòn CientìficaSIGLEESSpai