1,936 research outputs found

    15-item version of the Boston naming test: normative data for the Latin American spanish-speaking adult population.

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    Objective: Naming is commonly impaired in people with neurodegenerative diseases and brain injury, and as a result, its accurate assessment is essential. The aim of this study was to provide normative data for the 15-item Spanish version of the Boston Naming Test (BNT) for an adult population from eight Latin American countries/regions. Method: The total sample consisted of 2,828 participants from Argentina, Chile, Cuba, El Salvador, Mexico, Honduras, Paraguay, and Puerto Rico. Multiple regressions were used to generate normative data following a four-step process. Results: Regression models showed a linear effect of age on the 15-item BNT total score for Argentina, Chile, Mexico, and Puerto Rico. In contrast, Paraguay showed a quadratic age effect. Almost all countries showed a positive linear effect of education, except Cuba which had a quadratic effect. Sex was a significant predictor in Argentina, Chile, Cuba, and Mexico, where in women scored lower than men. Conclusions: This study generates normative data for the 15-item Spanish version of the BNT and offers a free open-source calculator that will assist in the efficacious use of this neuropsychological test in clinical practice and research

    Modeling Biological Pathway Dynamics With Timed Automata

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    Living cells are constantly subjected to a plethora of environmental stimuli that require integration into an appropriate cellular response. This integration takes place through signal transduction events that form tightly interconnected networks. The understanding of these networks requires to capture their dynamics through computational support and models. ANIMO (Analysis of Networks with Interactive MOdelling) is a tool that enables construction and exploration of executable models of biological networks, helping to derive hypotheses and to plan wet-lab experiments. The tool is based on the formalism of Timed Automata, which can be analysed via the UPPAAL model checker. Thanks to Timed Automata, we can provide a formal semantics for the domain-specific language used to represent signalling networks. This enforces precision and uniformity in the definition of signalling pathways, contributing to the integration of isolated signalling events into complex network models. We propose an approach to discretization of reaction kinetics that allows us to efficiently use UPPAAL as the computational engine to explore the dynamic behaviour of the network of interest. A user-friendly interface hides the use of Timed Automata from the user, while keeping the expressive power intact. Abstraction to single-parameter kinetics speeds up construction of models that remain faithful enough to provide meaningful insight. The resulting dynamic behaviour of the network components is displayed graphically, allowing for an intuitive and interactive modelling experience

    What can the Gulf of Mexico and Panama tell us about education and outreach?

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    ABSTRACT: A series of research grants funded by the National Science Foundation involved a major component about education and outreach as it pertained to marine algal diversity. These included comprehensive studies into 1) the diversity of the deep bank marine algae in the Gulf of Mexico (NSF Biodiversity Surveys and Inventories program) and the discovery of unsuspected eukaryotic life inhabiting rhodolith forming coralline algae (NSF DEB), 2) monographic research (NSF PEET), 3) advanced tropical phycology with the integration of modern and traditional techniques in the study of tropical algae of Panama (NSF PASI), among others.info:eu-repo/semantics/publishedVersio

    Voluntary Saccade Training Protocol in Persons With Parkinson’s Disease and Healthy Adults

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    Background: Voluntary saccade function gradually decreases during both the progression of Parkinson’s disease (PD) and neurologically healthy adult aging. Voluntary saccades display decreased length and increased saccade latency, duration, and the number of compensatory saccades in aging and PD. Saccades serve as the key eye movement for maintaining salient features of the visual environment on the high visual acuity fovea of the retina. Abnormal saccade behavior has been associated with freezing of gait in PD. We have not identified any studies that have investigated improvement in voluntary saccade function using voluntary saccade training.Objective: We report an experimental protocol that tests a training paradigm following the principle of specificity to improve voluntary saccade velocity and amplitude, while decreasing latency and the number of compensatory saccades.Methods: Persons with PD (n = 22) and persons with no known neurological disorders (n = 22) between the ages of 40 and 65 years will be recruited. In a randomized-block study design, all participants will perform voluntary saccades to targets in eight cardinal and intercardinal directions. In each of the eight sessions during the four-week intervention period, participants will train at three target amplitudes. Participants will perform 40 trials for each amplitude block, consisting of five randomly presented repetitions for each direction. Voluntary and reflexive saccades will be recorded pre- and post-intervention, along with clinical mobility assessment using the Movement Disorder Society Unified Parkinson’s Disease Rating Scale. Mobility scores, the amplitude, latency, and duration of the first saccade, and the number of saccades to reach the fixation target will be analyzed using an ANOVA of mixed effects.Discussion: This protocol holds promise as a potential method to improve voluntary saccade function in persons with PD. Should persons with PD not improve on any outcome following the intervention, this lack of response may support the use of saccade assessment as a response biomarker for the diagnosis of PD.Trial Registration: This protocol was retrospectively registered at ISRCTN (ISRCTN.com) since July 25, 2018. The first participant was recruited March 12, 2016. The protocol identifier is 17784042.Descriptive Title: A two-arm, pre/post-protocol to compare the effects of a four-week voluntary saccade training intervention in persons with Parkinson’s disease and healthy adults aged forty years or older

    Horizontal DNA transfer mechanisms of bacteria as weapons of intragenomic conflict

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    Horizontal DNA transfer (HDT) is a pervasive mechanism of diversification in many microbial species, but its primary evolutionary role remains controversial. Much recent research has emphasised the adaptive benefit of acquiring novel DNA, but here we argue instead that intragenomic conflict provides a coherent framework for understanding the evolutionary origins of HDT. To test this hypothesis, we developed a mathematical model of a clonally descended bacterial population undergoing HDT through transmission of mobile genetic elements (MGEs) and genetic transformation. Including the known bias of transformation toward the acquisition of shorter alleles into the model suggested it could be an effective means of counteracting the spread of MGEs. Both constitutive and transient competence for transformation were found to provide an effective defence against parasitic MGEs; transient competence could also be effective at permitting the selective spread of MGEs conferring a benefit on their host bacterium. The coordination of transient competence with cell-cell killing, observed in multiple species, was found to result in synergistic blocking of MGE transmission through releasing genomic DNA for homologous recombination while simultaneously reducing horizontal MGE spread by lowering the local cell density. To evaluate the feasibility of the functions suggested by the modelling analysis, we analysed genomic data from longitudinal sampling of individuals carrying Streptococcus pneumoniae. This revealed the frequent within-host coexistence of clonally descended cells that differed in their MGE infection status, a necessary condition for the proposed mechanism to operate. Additionally, we found multiple examples of MGEs inhibiting transformation through integrative disruption of genes encoding the competence machinery across many species, providing evidence of an ongoing "arms race." Reduced rates of transformation have also been observed in cells infected by MGEs that reduce the concentration of extracellular DNA through secretion of DNases. Simulations predicted that either mechanism of limiting transformation would benefit individual MGEs, but also that this tactic's effectiveness was limited by competition with other MGEs coinfecting the same cell. A further observed behaviour we hypothesised to reduce elimination by transformation was MGE activation when cells become competent. Our model predicted that this response was effective at counteracting transformation independently of competing MGEs. Therefore, this framework is able to explain both common properties of MGEs, and the seemingly paradoxical bacterial behaviours of transformation and cell-cell killing within clonally related populations, as the consequences of intragenomic conflict between self-replicating chromosomes and parasitic MGEs. The antagonistic nature of the different mechanisms of HDT over short timescales means their contribution to bacterial evolution is likely to be substantially greater than previously appreciated

    Siderophore-Mediated Zinc Acquisition Enhances Enterobacterial Colonization of the Inflamed Gut

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    Zinc is an essential cofactor for bacterial metabolism, and many Enterobacteriaceae express the zinc transporters ZnuABC and ZupT to acquire this metal in the host. However, the probiotic bacterium Escherichia coli Nissle 1917 (or “Nissle”) exhibits appreciable growth in zinc-limited media even when these transporters are deleted. Here, we show that Nissle utilizes the siderophore yersiniabactin as a zincophore, enabling Nissle to grow in zinc-limited media, to tolerate calprotectin-mediated zinc sequestration, and to thrive in the inflamed gut. We also show that yersiniabactin’s affinity for iron or zinc changes in a pH-dependent manner, with increased relative zinc binding as the pH increases. Thus, our results indicate that siderophore metal affinity can be influenced by the local environment and reveal a mechanism of zinc acquisition available to commensal and pathogenic Enterobacteriaceae

    Chromosomal-level assembly of the Asian Seabass genome using long sequence reads and multi-layered scaffolding

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    We report here the ~670 Mb genome assembly of the Asian seabass (Lates calcarifer), a tropical marine teleost. We used long-read sequencing augmented by transcriptomics, optical and genetic mapping along with shared synteny from closely related fish species to derive a chromosome-level assembly with a contig N50 size over 1 Mb and scaffold N50 size over 25 Mb that span ~90% of the genome. The population structure of L. calcarifer species complex was analyzed by re-sequencing 61 individuals representing various regions across the species' native range. SNP analyses identified high levels of genetic diversity and confirmed earlier indications of a population stratification comprising three clades with signs of admixture apparent in the South-East Asian population. The quality of the Asian seabass genome assembly far exceeds that of any other fish species, and will serve as a new standard for fish genomics

    The Non-existence of the Labor Demand/Supply Diagram, and Other Theorems of Institutional Economics

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    The most famous and influential diagram in modern (neoclassical) labor economics is the model of wage determination by supply and demand. Using concepts and ideas from institutional economics, I argue that the theory of a perfectly competitive labor market is logically contradictory and, hence, the demand/supply diagram cannot exist on the plane of pure theory. Four other fundamental theorems concerning labor markets are also derived, as are implications about the theoretical foundation of the field of industrial relations and the economic evaluation of labor and employment policy. In this article I accomplish four things of significance. The first is to demonstrate that the core diagram of neoclassical labor economics - the diagram of wage determination by demand and supply (D/S) - does not have logical coherence and thus has no existence on the plane of pure theory. The second is to deduce this conclusion using a core concept of institutional economics (i.e., transaction cost), thus demonstrating that the institutional approach to labor economics has theoretical explanatory power. The third is to use the transaction cost idea to also deduce four fundamental theorems concerning labor markets and wage determination. The fourth is to identify the core theoretical foundation of the field of industrial relations. This discussion also yields important implications for the economic evaluation of labor and employment policy, as well as interesting insights on the history of thought in labor economics. Working Paper 07-2

    Recent Region-wide Declines in Caribbean Reef Fish Abundance

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    Profound ecological changes are occurring on coral reefs throughout the tropics, with marked coral cover losses and concomitant algal increases, particularly in the Caribbean region. Historical declines in the abundance of large Caribbean reef fishes likely reflect centuries of overexploitation. However, effects of drastic recent degradation of reef habitats on reef fish assemblages have yet to be established. By using meta-analysis, we analyzed time series of reef fish density obtained from 48 studies that include 318 reefs across the Caribbean and span the time period 1955–2007. Our analyses show that overall reef fish density has been declining significantly for more than a decade, at rates that are consistent across all subregions of the Caribbean basin (2.7% to 6.0% loss per year) and in three of six trophic groups. Changes in fish density over the past half-century are modest relative to concurrent changes in benthic cover on Caribbean reefs. However, the recent significant decline in overall fish abundance and its consistency across several trophic groups and among both fished and nonfished species indicate that Caribbean fishes have begun to respond negatively to habitat degradation

    The political, research, programmatic, and social responses to adolescent sexual and reproductive health and rights in the 25 years since the International Conference on Population and Development

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    Among the ground-breaking achievements of the International Conference on Population and Development (ICPD) was its call to place adolescent sexual and reproductive health (ASRH) on global health and development agendas. This article reviews progressmade in low- and middle-income countries in the 25 years since the ICPD in six areas central to ASRH-adolescent pregnancy, HIV, child marriage, violence against women and girls, female genital mutilation, and menstrual hygiene and health. It also examines the ICPD's contribution to the progress made. The article presents epidemiologic levels and trends; political, research, programmatic and social responses; and factors that helped or hindered progress. To do so, it draws on research evidence and programmatic experience and the expertise and experiences of a wide number of individuals, including youth leaders, in numerous countries and organizations. Overall, looking across the six health topics over a 25-year trajectory, there has been great progress at the global and regional levels in putting adolescent health, and especially adolescent sexual and reproductive health and rights, higher on the agenda, raising investment in this area, building the epidemiologic and evidence-base, and setting norms to guide investment and action. At the national level, too, there has been progress in formulating laws and policies, developing strategies and programs and executing them, and engaging communities and societies in moving the agenda forward. Still, progress has been uneven across issues and geography. Furthermore, it has raced ahead sometimes and has stalled at others. The ICPD's Plan of Action contributed to the progress made in ASRH not just because of its bold call in 1994 but also because it provided a springboard for advocacy, investment, action, and research that remains important to this day. (C) 2019 Published by Elsevier Inc. on behalf of Society for Adolescent Health and Medicine
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