307 research outputs found
The contribution of the supplementary motor area to explicit and implicit timing: A high-definition transcranial Random Noise Stimulation (HD-tRNS) study
It is becoming increasingly accepted that timing tasks, and underlying temporal processes, can be partitioned on the basis of whether they require an explicit or implicit temporal judgement. Most neuroimaging studies of timing associated explicit timing tasks with activation of the supplementary motor area (SMA). However, transcranial magnetic stimulation (TMS) studies perturbing SMA functioning across explicit timing tasks have generally reported null effects, thus failing to causally link SMA to explicit timing. The present study probed the involvement of SMA in both explicit and implicit timing tasks within a single experiment and using HighDefinition transcranial Random Noise Stimulation (HD-tRNS), a previously less used technique in studies of the SMA. Participants performed two tasks that comprised the same stimulus presentation but differed in the received task instructions, which might or might not require explicit temporal judgments. Results showed a significant HD-tRNS-induced shift of perceived durations (i.e., overestimation) in the explicit timing task, whereas there was no modulation of implicit timing by HD-tRNS. Overall, these results provide initial noninvasive brain stimulation evidence on the contribution of the SMA to explicit and implicit timing tasks
Understanding, Assessing and Treating Prospective Memory Dysfunctions in Traumatic Brain Injury Patients
Our capacity to shape and direct our future behaviour is of fundamental importance in the development, pursuit, and maintenance of independence and autonomy from early childhood to late adulthood. A cognitive ability required for those functions is prospective memory (PM), which is the ability to form and remember to prospectively perform the intended action.
Researchers have extensively focused on PM impairment in patients with traumatic brain injury (TBI). However, there has been limited research into the assessment and treatment of PM impairment in TBI patients. Reliable and valid tests with normative data are necessary for health professionals working with people with PM impairments. This chapter reviews the principal findings on PM impairment in TBI patients, and the main procedures used to assess and rehabilitate PM
The dialectics of capital: learning from Gran Chaco
The critical impact of humans on the biosphere has led scientists to coin the term Anthropocene. The global environmental changes associated with it are happening under the aegis of capitalism. A transition towards sustainability requires a critical scrutiny of capitalism. The social–ecological system (SES) approach conceptualises the relationship between the socio-economic subsystem and the biosphere. However, in its various operationalisations it either treats the former as a black box or it fails to capture dynamic aspects. We address these limits and develop a Dialectical Socio-Ecological System (D-SES) framework, which combines process ecology with historical materialism, to describe the emergence and persistence of capitalist dynamics. We draw on data collected through fieldwork and desk research and deploy our framework to study capital-intensive agriculture in the Chaco Salteño, an important agricultural frontier in South America, obtaining some general insights. We open up the socio-economic subsystem and break it down into a lower-level material/economic sphere and an upper-level cultural/institutional sphere. Capitalist dynamics emerge out of the peculiar relationships occurring both within and between these spheres. This configuration shows the typical signs of autocatalysis. It attracts resources and capital to expand itself (centripetality). It becomes more complex and organised over time, fine-tuning production modes, cultures, and institutions (directionality). It is subject to the laws of competition and profit maximisation, which emerge independently from the individual actors and processes making up the system (autonomy). Finally, it engenders frictions, reflecting class antagonism between the direct producers and the appropriators of wealth. These frictions can become leverage points for a system’s transformation.EEA SaltaFil: Ceddia, M. Graziano. University of Bern. Centre for Development and Environment; SuizaFil: Montani, Rodrigo. University of Bern. Centre for Development and Environment; SuizaFil: Montani, Rodrigo. Universidad Nacional de Córdoba. Instituto de Antropología de Córdoba; ArgentinaFil: Montani, Rodrigo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Antropología de Córdoba; ArgentinaFil: Mioni, Walter Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; Argentina
Lack of Temporal Impairment in Patients With Mild Cognitive Impairment
In the present study, we investigate possible temporal impairment in patients with mild cognitive impairment (MCI) and the amount of temporal distortions caused by the presentation of emotional facial expressions (anger, shame, and neutral) in MCI patients and controls. Twelve older adults with MCI and 14 healthy older adults were enrolled in the present study. All participants underwent a complete neuropsychological evaluation. We used three timing tasks to tap temporal abilities, namely time bisection (standard intervals lasting 400 and 1600 ms), finger-tapping (free and 1 s), and simple reaction-time tasks. The stimuli used in the time bisection task were facial emotional stimuli expressing anger or shame to investigate a possible contribution of emotional information as previously observed in healthy adults. MCI patients showed temporal abilities comparable to controls. We observed an effect of facial emotional stimuli on time perception when data were analyzed in terms of proportion of long responses, and this result was mainly driven by the temporal overestimation when a facial expression of anger was presented in controls. Results seem to suggest that the severity of the cognitive dysfunction accounts more for subjective temporal impairment than a compromised internal clock
Demonstration of the Formation of the Caffeine-Dichloromethane-water Emulsion using Quantum Chemistry
Researchers have been concerned with the subsequent study of caffeine extraction. The objective of this article was to demonstrate how the caffeine-dichloromethane-water emulsion is formed. We use the theory of the electron transfer coefficient (ETC) as the cornerstone of our research. All the simulations of the interactions of the substances involved were calculated with the hyperchem simulator. The emulsion is formed because the ETC = 36,196 of the caffeine-CH2Cl2 interaction is the lowest of the cross-band interactions of the mixture. It will expect massive amounts of caffeine emulsified with CH2Cl2 and water. In conclusion, the gravitational well and the quantum well of caffeine coincide in being the lowest of all the wells calculated. It means that both CH2Cl2 and H2O will not destroy caffeine. That is, caffeine will be kept as a pure substance even after extraction with these two solvents. Although CH2Cl2 extracts more caffeine, due to its low ETC, the product for human consumption can be contaminated
Phosphorus Cycling in the Red Tide Incubator Region of Monterey Bay in Response to Upwelling
This study explores the cycling of phosphorus (P) in the euphotic zone following upwelling in northeastern Monterey Bay (the Red Tide Incubator region) of coastal California, with particular emphasis on how bacteria and phytoplankton that form harmful algal blooms mediate and respond to changes in P availability. In situ measurements of nutrient concentrations, phytoplankton community composition, and cell-specific alkaline phosphatase (AP) activity (determined via enzyme-labeled fluorescence assay) were measured during three cruises. Upwelling led to a 10-fold increase in dissolved inorganic (DIP) in surface waters, reaching ∼0.5 μmol L−1. This DIP was drawn down rapidly as upwelling relaxed over a period of 1 week. Ratios of nitrate to DIP drawdown (∼5:1, calculated as the change in nitrate divided by the change in DIP) were lower than the Redfield ratio of 16:1, suggesting that luxury P uptake was occurring as phytoplankton bloomed. Dissolved organic (DOP) remained relatively constant (∼0.3 μmol L−1) before and immediately following upwelling, but doubled as upwelling relaxed, likely due to phytoplankton excretion and release during grazing. This transition from a relatively high DIP:DOP ratio to lower DIP:DOP ratio was accompanied by a decline in the abundance of diatoms, which had low AP activity, toward localized, spatially heterogeneous blooms of dinoflagellates in the genera Prorocentrum, Ceratium, Dinophysis, Alexandrium, and Scrippsiella that showed high AP activity regardless of ambient DIP levels. A nutrient addition incubation experiment showed that phytoplankton growth was primarily limited by nitrate, followed by DIP and DOP, suggesting that P regulates phytoplankton physiology and competition, but is not a limiting nutrient in this region. AP activity was observed in bacteria associated with lysed cell debris and aggregates of particulate organic material, where it may serve to facilitate P regeneration, as well as affixed to the surfaces of intact phytoplankton cells, possibly indicative of close, beneficial phytoplankton–bacteria interactions
A focus group study for the design of a web-based tool for improving problem-solving in older adults
The development of easily accessible and usable social and cognitive enhancement trainings is becoming a priority to reduce the impact of aging on quality of life. Since most activities of daily living (e.g., making a meal) require problem-solving skills, problem-solving interventions could be used to improve and/or maintain functional abilities in aging to prolong independence. To design an effective problem-solving training and increase older adults' adherence to the training, this study examined older adults' perceptions of their challenges in activities of daily living, their skills and difficulties in using information technology (IT), and their motivations and expectations for participating in a web-based problem-solving training activity. Four focus groups (two in Italy and two in the Netherlands) were conducted with older adults aged between 65 and 84 years, a total of 27 participants. The data were analyzed using the Atlas.ti 8 software for the thematic analysis. The analysis identified five thematic areas: interests and activities, difficulties and concerns, experiences and motivations for training, expertise and resources, suggestions for the design of the new training. The results were used to develop a first prototype of a Shared, Web-based, Intelligent Flexible Thinking Training (SWIFT), adapted to future user needs. The participation of older adults in this design phase was critical to understanding their needs, motivations, and expectations regarding the implementation and use of a cognitive enhancement training.</p
Identification of harmful cyanobacteria in the Sacramento-San Joaquin Delta and Clear Lake, California by DNA barcoding.
Accurate identification of cyanobacteria using traditional morphological taxonomy is challenging due to the magnitude of phenotypic plasticity among natural algal assemblages. In this study, molecular approach was utilized to facilitate the accurate identification of cyanobacteria in the Sacramento-San Joaquin Delta and in Clear Lake in Northern California where recurring blooms have been observed over the past decades. Algal samples were collected from both water bodies in 2011 and the samples containing diverse cyanobacteria as identified by morphological taxonomy were chosen for the molecular analysis. The 16S ribosomal RNA genes (16S rDNA) and the adjacent internal transcribed spacer (ITS) regions were amplified by PCR from the mixed algal samples using cyanobacteria generic primers. The obtained sequences were analyzed by similarity search (BLASTN) and phylogenetic analysis (16S rDNA) to differentiate species sharing significantly similar sequences. A total of 185 plasmid clones were obtained of which 77 were successfully identified to the species level: Aphanizomenon flos-aquae, Dolichospermum lemmermannii (taxonomic synonym: Anabaena lemmermannii), Limnoraphis robusta (taxonomic synonym: Lyngbya hieronymusii f. robusta) and Microcystis aeruginosa. To date, Dolichospermum and Limnoraphis found in Clear Lake have only been identified to the genus lavel by microscopy. During the course of this study, morphological identification and DNA barcoding confirmed A. flos-aquae as the predominant cyanobacterium in the Sacramento-San Joaquin Delta indicating a shift from M. aeruginosa that have dominated the blooms in the past decade. Lastly, the species-specific identification of Limnoraphis robusta in Clear Lake is another significant finding as this cyanobacterium has, thus far, only been reported in Lake Atitlan blooms in Guatemala
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