131 research outputs found
Emergence of Rashba-/Dresselhaus Effects in Ruddlesden-Popper Halide Perovskites with Octahedral Rotations
Ruddelsden-Popper halide perovskites are highly versatile
quasi-two-dimensional energy materials with a wide range of tunable
optoelectronic properties. Here we use the all-inorganic
CsPbX Ruddelsden-Popper perovskites with X=I, Br, and Cl
to systematically model the effect of octahedral tilting distortions on the
energy landscape, band gaps, macroscopic polarization, and the emergence of
Rashba-/Dresselhaus splitting in these materials. We construct all unique
and structures following from octahedral tilts and use first-principles
density functional theory to calculate total energies, polarizations and band
structures, backed up by band gap calculations using the approach. Our
results provide design rules for tailoring structural distortions and
band-structure properties in all-inorganic Ruddelsden-Popper perovskites
through the interplay of the amplitude, direction, and chemical character of
the antiferrodistortive distortion modes contributing to each octahedral tilt
pattern. Our work emphasizes that, in contrast to 3D perovskites, polar
structures may arise from a combination of octahedral tilts, and
Rashba-/Dresselhaus splitting in this class of materials is determined by the
direction and Pb-I orbital contribution of the polar distortion mode
Synergistic effect of combined transcranial direct current stimulation/constraint-induced movement therapy in children and young adults with hemiparesis: study protocol
The neuroscience of social feelings:mechanisms of adaptive social functioning
Social feelings have conceptual and empirical connections with affect and emotion. In this review, we discuss how they relate to cognition, emotion, behavior and well-being. We examine the functional neuroanatomy and neurobiology of social feelings and their role in adaptive social functioning. Existing neuroscience literature is reviewed to identify concepts, methods and challenges that might be addressed by social feelings research. Specific topic areas highlight the influence and modulation of social feelings on interpersonal affiliation, parent-child attachments, moral sentiments, interpersonal stressors, and emotional communication. Brain regions involved in social feelings were confirmed by meta-analysis using the Neurosynth platform for large-scale, automated synthesis of functional magnetic resonance imaging data. Words that relate specifically to social feelings were identfied as potential research variables. Topical inquiries into social media behaviors, loneliness, trauma, and social sensitivity, especially with recent physical distancing for guarding public and personal health, underscored the increasing importance of social feelings for affective and second person neuroscience research with implications for brain development, physical and mental health, and lifelong adaptive functioning
High-resolution bathymetries and shorelines for the Great Lakes of the White Nile basin
This article is licensed under a Creative Commons Attribution 4.0 International License.HRBS-GLWNB 2020 presents the first open-source and high-resolution bathymetry, shoreline, and water level data for Lakes Victoria, Albert, Edward, and George in East Africa. For each Lake, these data have three primary products collected for this project. The bathymetric datasets were created from approximately 18 million acoustic soundings. Over 8,200 km of shorelines are delineated across the three lakes from high-resolution satellite systems and uncrewed aerial vehicles. Finally, these data are tied together by creating lake surface elevation models collected from GPS and altimeter measures. The data repository includes additional derived products, including surface areas, water volumes, shoreline lengths, lake elevation levels, and geodetic information. These data can be used to make allocation decisions regarding the freshwater resources within Africa, manage food resources on which many tens of millions of people rely, and help preserve the region’s endemic biodiversity. Finally, as these data are tied to globally consistent geodetic models, they can be used in future global and regional climate change models.ECU Open Access Publishing Support Fun
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Technical review of entrained design report
Morgantown Energy Technology Center (METC) is planning to expand its in-house coal gasification R&D capabilities by installing a research facility that can address a number of concepts including entrained, fluid bed, and catalytic gasification and flash pyrolysis. This Advanced Gasification Concepts (AGC) facility design, as it currently stands, includes piping and instrumentation diagrams, vessel drawings and specifications, instrumentation lists and specifications, and equipment layout and isometric drawings. Before the design is finalized, a critique is needed to ensure that the intended flexibility and objectives can be met. The design approach was evaluated to determine whether the present design will meet the research objectives, including the need for flexibility. Heat and material balances, critical velocity requirements, vessel arrangements, potential operational problems, and instrumentation were reviewed. The mechanical design review included a critique of the drawings and specifications, adherence to standards and codes, materials of construction, vessels, piping, valves, heaters, and fittings. In addition, utilities requirements, heat transfer and particulate removal calculations, and pumping and heat exchanger requirements were checked. An evaluation of the equipment cost includes a critique of the reliability of the equipment cost breakdown, the areas of cost uncertainty, and the areas for potential cost savings. A safety analysis is also provided
A Pilot Study Assessing Pharmacokinetics and Tolerability of Oral and Intravenous Baclofen in Healthy Adult Volunteers
Abstract Our objective was to characterize baclofen pharmacokinetics and safety given orally and intravenously. Twelve healthy subjects were enrolled in a randomized, open-label, crossover study and received single doses of baclofen: 3 or 5 mg given intravenously and 5 or 10 mg taken orally with a 48-hour washout. Blood samples for baclofen analysis were collected pre-dose and at regular intervals up to 24 hours post-dose. Clinical response was assessed by sedation scores, ataxia, and nystagmus. Mean absolute bioavailability of oral baclofen was 74%. Dose-adjusted areas under the curve between the oral and intravenous arms were statistically different (P ÂĽ .0024), whereas area under the curve variability was similar (coefficient of variation: 18%-24%). Adverse effects were mild in severity and not related to either dose or route of administration. Three-and 5-mg intravenous doses of baclofen were well tolerated. Seventy-four percent oral bioavailability indicates that smaller doses of intravenous baclofen are needed to attain comparable total drug exposures
Are women better mindreaders? Sex differences in neural correlates of mentalizing detected with functional MRI
<p>Abstract</p> <p>Background</p> <p>The ability to mentalize, i.e. develop a Theory of Mind (ToM), enables us to anticipate and build a model of the thoughts, emotions and intentions of others. It has long been hypothesised that women differ from men in their mentalizing abilities. In the present fMRI study we examined the impact of (1) gender (women vs. men) and (2) game partner (human vs. computer) on ToM associated neural activity in the medial prefrontal cortex. Groups of men (n = 12) and women (n = 12) interacted in an iterated classical prisoner's dilemma forced choice situation with alleged human and computer partners who were outside the scanner.</p> <p>Results</p> <p>Both the conditions of playing against putative human as well as computer partners led to activity increases in mPFC, ACC and rTPJ, constituting the classic ToM network. However, mPFC/ACC activity was more pronounced when participants believed they were playing against the alleged human partner. Differences in the medial frontal lobe activation related to the sex of the participants could be demonstrated for the human partner > computer partner contrast.</p> <p>Conclusion</p> <p>Our data demonstrate differences in medial prefrontal brain activation during a ToM task depending on both the gender of participants and the game partner.</p
Prefrontal dopamine and the dynamic control of human long-term memory
Dopaminergic projections to the prefrontal cortex support higher-order cognitive functions, and are critically involved in many psychiatric disorders that involve memory deficits, including schizophrenia. The role of prefrontal dopamine in long-term memory, however, is still unclear. We used an imaging genetics approach to examine the hypothesis that dopamine availability in the prefrontal cortex selectively affects the ability to suppress interfering memories. Human participants were scanned via functional magnetic resonance imaging while practicing retrieval of previously studied target information in the face of interference from previously studied non-target information. This retrieval practice (RP) rendered the non-target information less retrievable on a later final test—a phenomenon known as retrieval-induced forgetting (RIF). In total, 54 participants were genotyped for the catechol-O-methyltransferase (COMT) Val108/158Met polymorphism. The COMT Val108/158Met genotype showed a selective and linear gene-dose effect on RIF, with the Met allele, which leads to higher prefrontal dopamine availability, being associated with greater RIF. Mirroring the behavioral pattern, the functional magnetic resonance imaging data revealed that Met allele carriers, compared with Val allele carriers, showed a greater response reduction in inhibitory control areas of the right inferior frontal cortex during RP, suggesting that they more efficiently reduced interference. These data support the hypothesis that the cortical dopaminergic system is centrally involved in the dynamic control of human long-term memory, supporting efficient remembering via the adaptive suppression of interfering memories
Prevalence of hip dislocation among children with cerebral palsy in regions with and without a surveillance programme: a cross sectional study in Sweden and Norway
<p>Abstract</p> <p>Background</p> <p>Hip dislocation is a serious complication among children with cerebral palsy (CP). The aim of this study was to compare the prevalence of hip dislocation among children with CP in an area providing regular care with an area providing hip surveillance services.</p> <p>Methods</p> <p>This is a cross-sectional study in seven Norwegian counties providing regular care and one Swedish healthcare region where a hip surveillance programme was introduced in 1994. Data were provided by the Norwegian Cerebral Palsy Register and the CP Register in Southern Sweden. Children born 1996 - 2003 with moderate to severe CP, defined as Gross Motor Classification System (GMFCS) levels III - V, were included. In all, 119 Norwegian and 136 Swedish children fulfilled the criteria. In Norway, data on hip operations and radiographs of the hips were collected from medical records, while these data are collected routinely in the Swedish register. The hip migration percentage was measured on the recent radiographs. Hip dislocation was defined as a migration percent of 100%.</p> <p>Results</p> <p>The proportion of children at GMFCS levels III - V was 34% in the Norwegian and 38% in the Swedish population. In the Norwegian population, hip dislocation was diagnosed in 18 children (15.1%; CI: 9.8 - 22.6) compared with only one child (0.7%; 95% CI: 0.01 - 4.0) in Southern Sweden (p = < 0.001). Hip surgery was performed in 53 (44.5%) of the Norwegian children and in 43 (32%) of the Swedish children (p = 0.03). The total number of hip operations was 65 in Norway and 63 in Sweden. Norwegian children were first operated at a mean age of 7.6 years (SD: 2.9) compared with 5.7 years (SD: 2.3) in Sweden (p = 0.001).</p> <p>Conclusions</p> <p>The surveillance programme reduced the number of hip dislocations and the proportion of children undergoing hip surgery was lower. However, with the surveillance programme the first operation was performed at a younger age. Our results strongly support the effectiveness of a specifically designed follow-up programme for the prevention of hip dislocation in children with CP.</p
Virtual Partner Interaction (VPI): Exploring Novel Behaviors via Coordination Dynamics
Inspired by the dynamic clamp of cellular neuroscience, this paper introduces VPI—Virtual Partner Interaction—a coupled dynamical system for studying real time interaction between a human and a machine. In this proof of concept study, human subjects coordinate hand movements with a virtual partner, an avatar of a hand whose movements are driven by a computerized version of the Haken-Kelso-Bunz (HKB) equations that have been shown to govern basic forms of human coordination. As a surrogate system for human social coordination, VPI allows one to examine regions of the parameter space not typically explored during live interactions. A number of novel behaviors never previously observed are uncovered and accounted for. Having its basis in an empirically derived theory of human coordination, VPI offers a principled approach to human-machine interaction and opens up new ways to understand how humans interact with human-like machines including identification of underlying neural mechanisms
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