198 research outputs found
Edge momentum transport by neutrals: an interpretive numerical framework
Due to their high cross-field mobility, neutrals can contribute to momentum transport even at
the low relative densities found inside the separatrix and they can generate intrinsic rotation.
We use a charge-exchange dominated solution to the neutral kinetic equation, coupled to
neoclassical ions, to evaluate the momentum transport due to neutrals. Numerical solutions
to the drift-kinetic equation allow us to cover the full range of collisionality, including the
intermediate levels typical of the tokamak edge. In the edge there are several processes likely
to contribute to momentum transport in addition to neutrals. Therefore, we present here an
interpretive framework that can evaluate the momentum transport through neutrals based
on radial plasma profiles. We demonstrate its application by analysing the neutral angular
momentum flux for an L-mode discharge in the ASDEX Upgrade tokamak. The magnitudes of
the angular momentum fluxes we find here due to neutrals of 0.6
â
2
Nm
are comparable to the
net torque on the plasma from neutral beam injection, indicating the importance of neutrals for
rotation in the edge.VetenskapsrÄdet and Marie Sklodowska Curie Actions, Cofund, Project INCA 60039
The impact of tooth colour on the perceptions of age and social judgements.
ObjectivePsychological research has established that the presence of dental anomalies negatively impact social judgements. This study sought to determine the effects of tooth colour on the subjective ratings of social judgements in a group of Caucasian adults.MethodsA cross sectional experimental analogue design comprised fifty Caucasian adults: 25 women and 25 men. A total of 54 digitally modified photographs of Caucasian males and females (darkened, natural, whitened teeth) were evaluated. All participants evaluated each of the images on 12 characteristics: popularity, friendliness, social life, success, graduation, happiness, intelligence, perceived age, introversion/extraversion, self-confidence, attractiveness and satisfaction with the tooth shade. Analysis of variance (ANOVA) was used to compare ratings.ResultsParticipants associated darkened teeth with poorer subjective ratings, with the highest ratings been given to whitened teeth, and natural teeth being intermediate. These trends were similar across all participant age groups and gender. Further, the gender and age groups of the images had a significant effect on the appraisals. Faces of younger models received higher ratings than the faces of older models and female images were rated higher than the males.ConclusionIn the absence of other information, tooth colour exerts an influence upon the appraisals made in social situations. It appears that whitened tooth appearance is preferred to natural tooth appearance, irrespective of age and gender of the judge. The faces with more whitened dentition are perceived to be younger across all age groups and gender of the judges. Participants dissatisfied with their own tooth shade drew out more stereotypic behaviour.Clinical significance statementThis research used standardised tooth colour as a basis to investigate perceived age and social functioning. As clinicians face daily challenges to achieve patient satisfaction with respect to dental aesthetics, standardizing the colour may enhance the patientsâ satisfaction. Further, participants dissatisfied with their own tooth shade drew out more stereotypic behaviour. The whitened dentition may impair the psychological well-being of the individuals and is probably a reason for the increasing demand for cosmetic dental procedures. These results may be instructive for the development of a psycho-educational intervention to prevent any unrealistic expectations.</p
Herbivorous turtle ants obtain essential nutrients from a conserved nitrogen-recycling gut microbiome.
Nitrogen acquisition is a major challenge for herbivorous animals, and the repeated origins of herbivory across the ants have raised expectations that nutritional symbionts have shaped their diversification. Direct evidence for N provisioning by internally housed symbionts is rare in animals; among the ants, it has been documented for just one lineage. In this study we dissect functional contributions by bacteria from a conserved, multi-partite gut symbiosis in herbivorous Cephalotes ants through in vivo experiments, metagenomics, and in vitro assays. Gut bacteria recycle urea, and likely uric acid, using recycled N to synthesize essential amino acids that are acquired by hosts in substantial quantities. Specialized core symbionts of 17 studied Cephalotes species encode the pathways directing these activities, and several recycle N in vitro. These findings point to a highly efficient N economy, and a nutritional mutualism preserved for millions of years through the derived behaviors and gut anatomy of Cephalotes ants
CariesCare practice guide : consensus on evidence into practice
This CariesCare practice guide is derived from the International Caries Classification and Management System (ICCMS) and provides a structured update for dentists to help them deliver optimal caries care and outcomes for their patients. This '4D cycle' is a practice-building format, which both prevents and controls caries and can engage patients as long-term health partners with their practice. CariesCare International (CCIâą) promotes a patient-centred, risk-based approach to caries management designed for dental practice. This comprises a health outcomes-focused system that aims to maintain oral health and preserve tooth structure in the long-term. It guides the dental team through a four-step process (4D system), leading to personalised interventions: 1st D: Determine Caries Risk; 2nd D: Detect lesions, stage their severity and assess their activity status; 3rd D: Decide on the most appropriate care plan for the specific patient at that time; and then, finally, 4th D: Do the preventive and tooth-preserving care which is needed (including risk-appropriate preventive care; control of initial non-cavitated lesions; and conservative restorative treatment of deep dentinal and cavitated caries lesions). CariesCare International has designed this practice-friendly consensus guide to summarise best practice as informed by the best available evidence. Following the guide should also increase patient satisfaction, involvement, wellbeing and value, by being less invasive and more health-focused. For the dentist it should also provide benefits at the professional and practice levels including improved medico-legal protection
Consensus statement on future directions for the behavioral and social sciences in oral health
The behavioral and social sciences are central to understanding and addressing oral and craniofacial health, diseases, and conditions. With both basic and applied approaches, behavioral and social sciences are relevant to every discipline in dentistry and all dental, oral, and craniofacial sciences, as well as oral health promotion programs and health care delivery. Key to understanding multilevel, interacting influences on oral health behavior and outcomes, the behavioral and social sciences focus on individuals, families, groups, cultures, systems, societies, regions, and nations. Uniquely positioned to highlight the importance of racial, cultural, and other equity in oral health, the behavioral and social sciences necessitate a focus on both individuals and groups, societal reactions to them related to power, and environmental and other contextual factors. Presented here is a consensus statement that was produced through an iterative feedback process. The statement reflects the current state of knowledge in the behavioral and social oral health sciences and identifies future directions for the field, focusing on 4 key areas: behavioral and social theories and mechanisms related to oral health, use of multiple and novel methodologies in social and behavioral research and practice related to oral health, development and testing of behavioral and social interventions to promote oral health, and dissemination and implementation research for oral health. This statement was endorsed by over 400 individuals and groups from around the world and representing numerous disciplines in oral health and the behavioral and social sciences. Having reached consensus, action is needed to advance and further integrate and translate behavioral and social sciences into oral health research, oral health promotion and health care, and the training of those working to ensure oral health for all
Facts, Values and Quanta
Quantum mechanics is a fundamentally probabilistic theory (at least so far as
the empirical predictions are concerned). It follows that, if one wants to
properly understand quantum mechanics, it is essential to clearly understand
the meaning of probability statements. The interpretation of probability has
excited nearly as much philosophical controversy as the interpretation of
quantum mechanics. 20th century physicists have mostly adopted a frequentist
conception. In this paper it is argued that we ought, instead, to adopt a
logical or Bayesian conception. The paper includes a comparison of the orthodox
and Bayesian theories of statistical inference. It concludes with a few remarks
concerning the implications for the concept of physical reality.Comment: 30 pages, AMS Late
Association of a marker of N-acetylglucosamine with progressive multiple sclerosis and neurodegeneration
IMPORTANCE: N-glycan branching modulates cell surface receptor availability, and its deficiency in mice promotes inflammatory demyelination, reduced myelination, and neurodegeneration. N-acetylglucosamine (GlcNAc) is a rate-limiting substrate for N-glycan branching, but, to our knowledge, endogenous serum levels in patients with multiple sclerosis (MS) are unknown. OBJECTIVE: To investigate a marker of endogenous serum GlcNAc levels in patients with MS. DESIGN, SETTING, AND PARTICIPANTS: A cross-sectional discovery study and cross-sectional confirmatory study were conducted at 2 academic MS centers in the US and Germany. The discovery study recruited 54 patients with MS from an outpatient clinic as well as 66 healthy controls between April 20, 2010, and June 21, 2013. The confirmatory study recruited 180 patients with MS from screening visits at an academic MS study center between April 9, 2007, and February 29, 2016. Serum samples were analyzed from December 2, 2013, to March 2, 2015. Statistical analysis was performed from February 23, 2020, to March 18, 2021. MAIN OUTCOMES AND MEASURES: Serum levels of GlcNAc plus its stereoisomers, termed N-acetylhexosamine (HexNAc), were assessed using targeted tandem mass spectroscopy. Secondary outcomes (confirmatory study) comprised imaging and clinical disease markers. RESULTS: The discovery cohort included 66 healthy controls (38 women; mean [SD] age, 42 [20] years), 33 patients with relapsing-remitting MS (RRMS; 25 women; mean [SD] age, 50 [11] years), and 21 patients with progressive MS (PMS; 14 women; mean [SD] age, 55 [7] years). The confirmatory cohort included 125 patients with RRMS (83 women; mean [SD] age, 40 [9] years) and 55 patients with PMS (22 women; mean [SD] age, 49 [80] years). In the discovery cohort, the mean (SD) serum level of GlcNAc plus its stereoisomers (HexNAc) was 710 (174) nM in healthy controls and marginally reduced in patients with RRMS (mean [SD] level, 682 [173] nM; Pâ=â.04), whereas patients with PMS displayed markedly reduced levels compared with healthy controls (mean [SD] level, 548 [101] nM; Pâ=â9.55âĂâ10(-9)) and patients with RRMS (Pâ=â1.83âĂâ10(-4)). The difference between patients with RRMS (mean [SD] level, 709 [193] nM) and those with PMS (mean [SD] level, 405 [161] nM; Pâ=â7.6âĂâ10(-18)) was confirmed in the independent confirmatory cohort. Lower HexNAc serum levels correlated with worse expanded disability status scale scores (Ïâ=â-0.485; Pâ=â4.73âĂâ10(-12)), lower thalamic volume (tâ=â1.7; Pâ=â.04), and thinner retinal nerve fiber layer (Bâ=â0.012 [SEâ=â7.5âĂâ10(-11)]; Pâ=â.008). Low baseline serum HexNAc levels correlated with a greater percentage of brain volume loss at 18 months (tâ=â1.8; Pâ=â.04). CONCLUSIONS AND RELEVANCE: This study suggests that deficiency of GlcNAc plus its stereoisomers (HexNAc) may be a biomarker for PMS. Previous preclinical, human genetic, and ex vivo human mechanistic studies revealed that N-glycan branching and/or GlcNAc may reduce proinflammatory responses, promote myelin repair, and decrease neurodegeneration. Combined, the data suggest that GlcNAc deficiency may be associated with progressive disease and neurodegeneration in patients with MS
Author Correction: Herbivorous turtle ants obtain essential nutrients from a conserved nitrogen-recycling gut microbiome.
The originally published version of the Supplementary Information file associated with this Article contained an error in Supplementary Figure 3. Panel b was inadvertently replaced with a duplicate of panel a. The error has now been fixed and the corrected version of the Supplementary Information PDF is available to download from the HTML version of the Article
The Small Gtpase, Rap1, Mediates Cd31-Induced Integrin Adhesion
Integrin-mediated leukocyte adhesion is a critical aspect of leukocyte function that is tightly regulated by diverse stimuli, including chemokines, antigen receptors, and adhesion receptors. How cellular signals from CD31 and other adhesion amplifiers are integrated with those from classical mitogenic stimuli to regulate leukocyte function remains poorly understood. Here, we show that the cytoplasmic tail of CD31, an important integrin adhesion amplifier, propagates signals that induce T cell adhesion via ÎČ1 (VLA-4) and ÎČ2 (LFA-1) integrins. We identify the small GTPase, Rap1, as a critical mediator of this effect. Importantly, CD31 selectively activated the small Ras-related GTPase, Rap1, but not Ras, R-Ras, or Rap2. An activated Rap1 mutant stimulated T lymphocyte adhesion to intercellular adhesion molecule (ICAM) and vascular cell adhesion molecule (VCAM), as did the Rap1 guanine nucleotide exchange factor C3G and a catalytically inactive mutant of RapGAP. Conversely, negative regulators of Rap1 signaling blocked CD31-dependent adhesion. These findings identify a novel important role for Rap1 in regulating ligand-induced cell adhesion and suggest that Rap1 may play a more general role in coordinating adhesion-dependent signals during leukocyte migration and extravasation. Our findings also suggest an alternative mechanism, distinct from interference with Ras-proximal signaling, by which Rap1 might mediate transformation reversion
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