546 research outputs found
Functional cerebral changes in multiple sclerosis patients during an autobiographical memory test.
Our aim was to investigate the functional underpinnings of autobiographical memory (AM) impairment in multiple sclerosis (MS) patients. To that end, 18 patients and 18 controls underwent the autobiographical interview (AI). Subsequently, the 36 participants underwent a functional magnetic resonance imaging (fMRI) session designed to assess the construction and elaboration of AMs. A categorical control task was also presented. Patients were trained in the fMRI procedure to optimise the procedural aspects accompanying the task itself. Although the patients obtained significantly poorer AI scores (p < .001), their performance on the easier AM fMRI task was efficiently carried out, allowing relevant comparisons with healthy controls. Relatively to healthy controls, the patients showed increased and bilateral cerebral activations (p < .005) during the construction and elaboration phases. The prefrontal, temporal and posterior cerebral region activations were located within the core network sustaining AM, with the bilateral prefrontal region being centrally involved. The parametric neural responses to the difficulty of access and amount of details of memories were also significantly different for the two groups, with the right hippocampal region showing a particularly increased recruitment (p < .005). The findings suggested the presence of functional cerebral changes during AM performance and supported the presence of AM retrieval deficit in MS patients.journal articleresearch support, non-u.s. gov't20152014 09 22importe
Empirisch abgeleitete Empfehlungen für den Auf- und Ausbau von Tageshospizen in Deutschland – Ergebnisse einer Delphi-Befragung mit Expert:innen
Introduction: A needs-based and patient-oriented hospice and palliative care also includes day hospices as a specialised semi-inpatient care offer. The establishment and development of these facilities in Germany has been rather unsystematic. In order to ensure quality and adequacy of these structures, research is needed. Methods: A Delphi consensus study was conducted online from November 2022 to February 2023 aiming at generating recommendations for the development and expansion of day hospices in Germany. For each recommendation, the participants indicated on a four-point verbal rating scale how much they agreed upon a) the relevance and b) the feasibility of the recommendation. Items were considered consented when 80 % of the participants (strongly) agreed with the recommendation regarding both criteria. If no consensus was reached, the recommendations were revised according to the participants’ free text comments and presented in the next Delphi round. Descriptive analyses were applied. Results: A total of 64 experts participated in the first Delphi round and 44 in the second. In round 1, 34 recommendations and in round 2 six recommendations were consented. The final set contains a total of 40 recommendations: 18 on the tasks of day hospices, 13 on cooperation, 7 on funding, and 2 on public relations. Discussion: Recommendations for the development and expansion of day hospices in Germany were developed. Due to their highly rated feasibility, the recommendations should be directly transferable into care practice. It remains to be seen to what extent they will be taken into account in the renegotiation of the framework agreement for day hospices. Conclusion: The Delphi-consented recommendations provide a basis to guide action in the currently very dynamic development of hospice work and palliative care in Germany.Hintergrund: Zu einer bedarfsgerechten, patient:innenenorientierten Hospiz- und Palliativversorgung zählen auch Tageshospize als spezialisierte ambulante Versorgungsangebote. Aufbau und Entwicklung von Tageshospizen in Deutschland erfolgten bislang individuell und eigeninitiativ. Zur langfristigen Sicherstellung der Qualität und Bedarfsangemessenheit von Tageshospizen bedarf es wissenschaftlicher Erkenntnisse und Grundlagen. Methode: Von November 2022 bis Februar 2023 erfolgte eine deutschlandweite Online-Delphi-Befragung mit Expert:innen, in der Empfehlungen für den Auf- und Ausbau von Tageshospizen in Deutschland konsentiert wurden. Teilnehmende gaben zu jeder Empfehlung auf einer vierstufigen Rangskala an, wie sehr sie a) der Relevanz der Empfehlung und b) der Umsetzbarkeit der Empfehlung im Versorgungsalltag (nicht) zustimmen. Konsens wurde erreicht, wenn 80 % der Teilnehmenden einer Empfehlung in beiden Kriterien (eher) zustimmten. Wurde kein Konsens erreicht, wurden die Empfehlungen basierend auf Freitextkommentaren der Teilnehmenden angepasst und in der darauffolgenden Runde erneut zur Abstimmung gestellt. Die Analysen erfolgten deskriptiv. Ergebnisse: An der ersten Befragungsrunde beteiligten sich 64 und an der zweiten 44 Expert:innen. In Runde 1 wurden 34 und in Runde 2 sechs Empfehlungen konsentiert. Das finale Set enthält insgesamt 40 Empfehlungen: 18 zu Aufgaben, 13 zur Zusammenarbeit, 7 zur Finanzierung und 2 zur Öffentlichkeitsarbeit von Tageshospizen. Diskussion: Es konnten konkrete Empfehlungen zum Auf- und Ausbau von Tageshospizen in Deutschland entwickelt werden. Die Empfehlungen sollten aufgrund ihrer hoch bewerteten Umsetzbarkeit direkt in die Versorgungspraxis überführbar sein. Inwiefern die Empfehlungen in der Neuverhandlung der Rahmenvereinbarung für Tageshospize berücksichtigt werden, gilt es abzuwarten. Schlussfolgerung: Die vorliegenden Empfehlungen können handlungsweisend bei der aktuell sehr dynamischen Weiterentwicklung der Hospizarbeit und Palliativversorgung in Deutschland genutzt werden
Distinct conformations of the HIV-1 V3 loop crown are targetable for broad neutralization.
The V3 loop of the HIV-1 envelope (Env) protein elicits a vigorous, but largely non-neutralizing antibody response directed to the V3-crown, whereas rare broadly neutralizing antibodies (bnAbs) target the V3-base. Challenging this view, we present V3-crown directed broadly neutralizing Designed Ankyrin Repeat Proteins (bnDs) matching the breadth of V3-base bnAbs. While most bnAbs target prefusion Env, V3-crown bnDs bind open Env conformations triggered by CD4 engagement. BnDs achieve breadth by focusing on highly conserved residues that are accessible in two distinct V3 conformations, one of which resembles CCR5-bound V3. We further show that these V3-crown conformations can, in principle, be attacked by antibodies. Supporting this conclusion, analysis of antibody binding activity in the Swiss 4.5 K HIV-1 cohort (n = 4,281) revealed a co-evolution of V3-crown reactivities and neutralization breadth. Our results indicate a role of V3-crown responses and its conformational preferences in bnAb development to be considered in preventive and therapeutic approaches
Bottom-up effects of plant diversity on multitrophic interactions in a biodiversity experiment
Biodiversity is rapidly declining1, and this may negatively affect ecosystem processes, including economically important ecosystem services. Previous studies have shown that biodiversity has positive effects on organisms and processes4 across trophic levels. However, only a few studies have so far incorporated an explicit food-web perspective. In an eight-year biodiversity experiment, we studied an unprecedented range of above- and below-ground organisms and multitrophic interactions. A multitrophic data set originating from a single long-term experiment allows mechanistic insights that would not be gained from meta-analysis of different experiments. Here we show that plant diversity effects dampen with increasing trophic level and degree of omnivory. This was true both for abundance and species richness of organisms. Furthermore, we present comprehensive above-ground/below-ground biodiversity food webs. Both above ground and below ground, herbivores responded more strongly to changes in plant diversity than did carnivores or omnivores. Density and richness of carnivorous taxa was independent of vegetation structure. Below-ground responses to plant diversity were consistently weaker than above-ground responses. Responses to increasing plant diversity were generally positive, but were negative for biological invasion, pathogen infestation and hyperparasitism. Our results suggest that plant diversity has strong bottom-up effects on multitrophic interaction networks, with particularly strong effects on lower trophic levels. Effects on higher trophic levels are indirectly mediated through bottom-up trophic cascades
Participation of Candida albicans transcription factor Rlm1 in cell wall biogenesis and virulence
Candida albicans cell wall is important for growth and interaction with the environment. RLM1 is one of the putative transcription factors involved in the cell wall integrity pathway, which plays an important role in the maintenance of the cell wall integrity. In this work we investigated the involvement of RLM1 in the cell wall biogenesis and in virulence. Newly constructed C. albicans Δ/Δrlm1 mutants showed typical cell wall weakening phenotypes, such as hypersensitivity to Congo Red, Calcofluor White, and caspofungin (phenotype reverted in the presence of sorbitol), confirming the involvement of RLM1 in the cell wall integrity. Additionally, the cell wall of C. albicans Δ/Δrlm1 showed a significant increase in chitin (213%) and reduction in mannans (60%), in comparison with the wild-type, results that are consistent with cell wall remodelling. Microarray analysis in the absence of any stress showed that deletion of RLM1 in C. albicans significantly down-regulated genes involved in carbohydrate catabolism such as DAK2, GLK4, NHT1 and TPS1, up-regulated genes involved in the utilization of alternative carbon sources, like AGP2, SOU1, SAP6, CIT1 or GAL4, and genes involved in cell adhesion like ECE1, ALS1, ALS3, HWP1 or RBT1. In agreement with the microarray results adhesion assays showed an increased amount of adhering cells and total biomass in the mutant strain, in comparison with the wild-type. C. albicans mutant Δ/Δrlm1 strain was also found to be less virulent than the wild-type and complemented strains in the murine model of disseminated candidiasis. Overall, we showed that in the absence of RLM1 the modifications in the cell wall composition alter yeast interaction with the environment, with consequences in adhesion ability and virulence. The gene expression findings suggest that this gene participates in the cell wall biogenesis, with the mutant rearranging its metabolic pathways to allow the use of alternative carbon sources.This work was supported by CBMA (Centre of Molecular and Environmental Biology) through the FCT (Fundacao para a Ciencia e Tecnologia) project PEst-C/BIA/UI4050/2011. Yolanda Delgado-Silva was supported by an ALbAN scholarship (No E07D400922PE), and Alexandra Correia by SFRH/BD/31354/2006 fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Tactual perception: a review of experimental variables and procedures
This paper reviews literature on tactual perception. Throughout this review we will highlight some of the most relevant variables in touch literature: interaction between touch and other senses; type of stimuli, from abstract stimuli such as vibrations, to two- and three-dimensional stimuli, also considering concrete stimuli such as the relation between familiar and unfamiliar stimuli or the haptic perception of faces; type of participants, separating studies with blind participants, studies with children and adults, and an analysis of sex differences in performance; and finally, type of tactile exploration, considering conditions of active and passive touch, the relevance of movement in touch and the relation between exploration and time. This review intends to present an organised overview of the main variables in touch experiments, attending to the main findings described in literature, to guide the design of future works on tactual perception and memory.This work was funded by the Portuguese “Foundation for Science and Technology” through PhD scholarship SFRH/BD/35918/2007
Diversity Promotes Temporal Stability across Levels of Ecosystem Organization in Experimental Grasslands
The diversity–stability hypothesis states that current losses of biodiversity can impair the ability of an ecosystem to dampen the effect of environmental perturbations on its functioning. Using data from a long-term and comprehensive biodiversity experiment, we quantified the temporal stability of 42 variables characterizing twelve ecological functions in managed grassland plots varying in plant species richness. We demonstrate that diversity increases stability i) across trophic levels (producer, consumer), ii) at both the system (community, ecosystem) and the component levels (population, functional group, phylogenetic clade), and iii) primarily for aboveground rather than belowground processes. Temporal synchronization across studied variables was mostly unaffected with increasing species richness. This study provides the strongest empirical support so far that diversity promotes stability across different ecological functions and levels of ecosystem organization in grasslands
Gene Expression Profiling in Cells with Enhanced Îł-Secretase Activity
BACKGROUND: Processing by gamma-secretase of many type-I membrane protein substrates triggers signaling cascades by releasing intracellular domains (ICDs) that, following nuclear translocation, modulate the transcription of different genes regulating a diverse array of cellular and biological processes. Because the list of gamma-secretase substrates is growing quickly and this enzyme is a cancer and Alzheimer's disease therapeutic target, the mapping of gamma-secretase activity susceptible gene transcription is important for sharpening our view of specific affected genes, molecular functions and biological pathways. METHODOLOGY/PRINCIPAL FINDINGS: To identify genes and molecular functions transcriptionally affected by gamma-secretase activity, the cellular transcriptomes of Chinese hamster ovary (CHO) cells with enhanced and inhibited gamma-secretase activity were analyzed and compared by cDNA microarray. The functional clustering by FatiGO of the 1,981 identified genes revealed over- and under-represented groups with multiple activities and functions. Single genes with the most pronounced transcriptional susceptibility to gamma-secretase activity were evaluated by real-time PCR. Among the 21 validated genes, the strikingly decreased transcription of PTPRG and AMN1 and increased transcription of UPP1 potentially support data on cell cycle disturbances relevant to cancer, stem cell and neurodegenerative diseases' research. The mapping of interactions of proteins encoded by the validated genes exclusively relied on evidence-based data and revealed broad effects on Wnt pathway members, including WNT3A and DVL3. Intriguingly, the transcription of TERA, a gene of unknown function, is affected by gamma-secretase activity and was significantly altered in the analyzed human Alzheimer's disease brain cortices. CONCLUSIONS/SIGNIFICANCE: Investigating the effects of gamma-secretase activity on gene transcription has revealed several affected clusters of molecular functions and, more specifically, 21 genes that hold significant potential for a better understanding of the biology of gamma-secretase and its roles in cancer and Alzheimer's disease pathology
Using Plant Functional Traits to Explain Diversity–Productivity Relationships
Background: The different hypotheses proposed to explain positive species richness–productivity relationships, i.e. selection effect and complementarity effect, imply that plant functional characteristics are at the core of a mechanistic understanding of biodiversity effects.
Methodology/Principal Findings: We used two community-wide measures of plant functional composition, (1) community- weighted means of trait values (CWM) and (2) functional trait diversity based on Rao’s quadratic diversity (FDQ) to predict biomass production and measures of biodiversity effects in experimental grasslands (Jena Experiment) with different species richness (2, 4, 8, 16 and 60) and different functional group number and composition (1 to 4; legumes, grasses, small herbs, tall herbs) four years after establishment. Functional trait composition had a larger predictive power for community biomass and measures of biodiversitity effects (40–82% of explained variation) than species richness per se (,1–13% of explained variation). CWM explained a larger amount of variation in community biomass (80%) and net biodiversity effects (70%) than FDQ (36 and 38% of explained variation respectively). FDQ explained similar proportions of variation in complementarity effects (24%, positive relationship) and selection effects (28%, negative relationship) as CWM (27% of explained variation for both complementarity and selection effects), but for all response variables the combination of CWM and FDQ led to significant model improvement compared to a separate consideration of different components of functional trait composition. Effects of FDQ were mainly attributable to diversity in nutrient acquisition and life-history strategies. The large spectrum of traits contributing to positive effects of CWM on biomass production and net biodiversity effects indicated that effects of dominant species were associated with different trait combinations.
Conclusions/Significance: Our results suggest that the identification of relevant traits and the relative impacts of functional identity of dominant species and functional diversity are essential for a mechanistic understanding of the role of plant diversity for ecosystem processes such as aboveground biomass production
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