2,941 research outputs found
Smectites versus palagonites in Mars soil: Evidence from simulations of Viking biology labeled release experiments
The results of an experimental comparison between palagonites and a smectite (montmorillonite) in the simulation of the Viking Biology Labeled Release (LR) experiment and conclusions regarding their suitability as MarSAMs are reproved. It was found that palagonites do not cause formate decomposition and C-14 release in their natural form or after acidification and thus cannot be a completely satisfactory analog to the Mars soil studied by Viking
Automated individual-level parcellation of Broca’s region based on resting-state functional connectivity
The Role of Social Anarchism and Geography in Constructing a Radical Agenda: A Response to David Harvey
David Harvey’s response to Simon Springer (2014) raises important questions about the places from which to draw ideas for a radical geography agenda. Nevertheless, Harvey ignores critical contributions that social anarchists (including social geographers) have made to understanding both the theory and practice of social transformation. We draw on studies of the anarchist movement in Spain before and during the Spanish Civil War to explore some of what social anarchism has to contribute to geography and contemporary struggles for a more equitable society
Gr\"obner Bases and Nullstellens\"atze for Graph-Coloring Ideals
We revisit a well-known family of polynomial ideals encoding the problem of
graph--colorability. Our paper describes how the inherent combinatorial
structure of the ideals implies several interesting algebraic properties.
Specifically, we provide lower bounds on the difficulty of computing Gr\"obner
bases and Nullstellensatz certificates for the coloring ideals of general
graphs. For chordal graphs, however, we explicitly describe a Gr\"obner basis
for the coloring ideal, and provide a polynomial-time algorithm.Comment: 16 page
Longitudinal changes in resting-state fMRI from age 5 to age 6 years covary with language development
Resting-state functional magnetic resonance imaging is a powerful technique to study the whole-brain neural connectivity that underlies cognitive systems. The present study aimed to define the changes in neural connectivity in their relation to language development. Longitudinal resting-state functional data were acquired from a cohort of preschool children at age 5 and one year later, and changes in functional connectivity were correlated with language performance in sentence comprehension. For this, degree centrality, a voxel-based network measure, was used to assess age-related differences in connectivity at the whole-brain level. Increases in connectivity with age were found selectively in a cluster within the left posterior superior temporal gyrus and sulcus (STG/STS). In order to further specify the connection changes, a secondary seed-based functional connectivity analysis on this very cluster was performed. The correlations between resting-state functional connectivity (RSFC) and language performance revealed developmental effects with age and, importantly, also dependent on the advancement in sentence comprehension ability over time. In children with greater advancement in language abilities, the behavioral improvement was positively correlated with RSFC increase between left posterior STG/STS and other regions of the language network, i.e., left and right inferior frontal cortex. The age-related changes observed in this study provide evidence for alterations in the language network as language develops and demonstrates the viability of this approach for the investigation of normal and aberrant language development
Noninvasive Metrics for Identification of Brain Injury Deficits in Piglets
Balance and bispectral index metrics were evaluated in piglets following focal and diffuse brain injury. A significant decrease in bispectral index existed at 24 hours after diffuse brain injury, but not after focal injury. Postural sway increased at 1–6 hours after both focal and diffuse injuries
Finite Element Model Predictions of Intracranial Hemorrhage From Non-impact, Rapid Head Rotations in the Piglet
Clinicians are charged with the significant task of distinguishing between accidental and inflicted head trauma. Oftentimes this distinction is straightforward, but many times probabilities of injuries from accidental scenarios are unknown making the differential diagnosis difficult. For example, it is unknown whether intracranial hemorrhage (IH) can occur at a location other than a focal contact site following a low height fall. To create a foundation for predicting regional IH in infants, we sought to identify the biomechanical response and injury threshold best able to predict IH in 3–5 day old piglets. First, finite element (FE) model simulations of in situ animal studies were performed to ascertain the optimal representation of the pia-arachnoid complex, cerebrospinal fluid and cortical vasculature (PCC) for predicting brain strain and brain/skull displacement. Second, rapid head rotations resulting in various degrees of IH were simulated (n = 24) to determine the biomechanical predictor and injury threshold most closely correlated with IH. FE models representing the PCC with either spring connectors or solid elements between the brain and skull resulted in peak brain strain and brain/skull displacement similar to measured values in situ. However, when predicting IH, the spring connector representation of the PCC had the best predictive capability for IH with a sensitivity of 80% and a specificity of 85% when ≥1% of all spring connectors had at least a peak strain of 0.31 mm/mm. These findings and reported methodology will be used in the development of a human infant FE model to simulate real-world falls and identify injury thresholds for predicting IH in infants
Orale Mukositis bei Patienten unter Tumortherapie
Zusammenfassung: Zu den unerwünschten Nebenwirkungen bestimmter Chemo- und Radiotherapien gehört die orale Mukositis, eine Entzündung der Mundschleimhaut. Da sie die Lebensqualität der Patienten in hohem Maße beeinträchtigen kann, sollten Pflegende der Mundhygiene einen besonders hohen Stellenwert beimessen. In der täglichen Praxis wird die orale Mukositis oft kontrovers diskutiert. In diesem Artikel werden aktuelle theoriebasierte und erfahrungsbasierte Grundlagen und Anleitungen für die Pflege und Behandlung vorgestell
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