267 research outputs found
CMB Lensing Constraints on Neutrinos and Dark Energy
Signatures of lensing of the cosmic microwave background radiation by
gravitational potentials along the line of sight carry with them information on
the matter distribution, neutrino masses, and dark energy properties. We
examine the constraints that Planck, PolarBear, and CMBpol future data,
including from the B-mode polarization or the lensing potential, will be able
to place on these quantities. We simultaneously fit for neutrino mass and dark
energy equation of state including time variation and early dark energy
density, and compare the use of polarization power spectra with an optimal
quadratic estimator of the lensing. Results are given as a function of
systematics level from residual foreground contamination. A realistic CMBpol
experiment can effectively constrain the sum of neutrino masses to within 0.05
eV and the fraction of early dark energy to 0.002. We also present a
surprisingly simple prescription for calculating dark energy equation of state
constraints in combination with supernova distances from JDEM.Comment: 18 pages, 14 figures. Small changes made to match version to be
published in Phys. Rev.
The antiviral function of the RNA dependent Adenosine deaminase in innate immunity
Die angeborene Immunantwort von Säugetieren ist die erste wirkungsvolle Barriere gegen eindringende Pathogene, die sowohl Infektionen als auch die Entstehung von Neoplasien verhindern kann. Insbesondere wird durch sie die Ausbreitung und Replikation von Viren wirksam bekämpft. Bei RNA-Viren wird die angeborene Immunabwehr in infizierten Zellen von der doppelsträngigen RNA aktiviert, die während der Replikation oder Transkription dieser Viren entsteht. Es kommt zur Sezernierung von Interferon-alpha und -beta (IFN-alpha/beta), die wiederum die Expression einer Reihe von antiviralen Proteinen stimulieren. Eines dieser Proteine ist die IFN-alpha-induzierbare RNA-abhängige Adenosin Desaminase (iADAR-1). Ziel dieser Arbeit war es, die Rolle der iADAR-1 in der Immunabwehr näher zu charakterisieren. Bisher wurde die antivirale Aktivität der iADAR-1 gegen verschiedene Virusstämme, deren Genome Adenosin zu Guanosin (A->G) Hypermutationen aufweisen, nur angenommen, jedoch noch nicht direkt gezeigt [4]. In dieser Arbeit wurde am Beispiel des Glykoproteins (GP) des lymphozytären Choriomeningitis Virus (LCMV) untersucht, ob solche A->G Mutationen im viralen Genom tatsächlich durch die iADAR-1 verursacht werden und ob dadurch die Funktion der viralen Proteine und damit die Infektiösität von LCMV reduziert wird. Des Weiteren wurde die Induktion der iADAR-1 durch die Infektion mit LCMV und die Wirkung der iADAR-1 auf die Replikation von LCMV analysiert. Bekannt war nur, dass die iADAR-1 durch IFN-alpha selbst oder durch die Infektion von Makrophagen mit Adenoviren induziert wird. In dieser Arbeit wurde erstmals für Fibroblasten, neuronale Zellen und in vivo in Mäusen nachgewiesen, dass die iADAR-1 direkt durch die Infektion mit LCMV hochreguliert wird. Dies ist ein weiterer Hinweis, dass die iADAR-1 zu den antiviralen Effektormolekülen der angeborenen Immunabwehr zählt. LCMV induzierte die Expression der iADAR-1 sowohl auf mRNA- als auch auf Proteinebene. Im Gegensatz zu Vaccinia- und Adenoviren, die die Aktivität der iADAR-1 inhibieren [5, 6], konnte bei der Infektion von SH-SY5Y-Zellen mit LCMV keine reduzierte Aktivität der iADAR-1 festgestellt werden. Ferner konnte das schon in anderen Viren beobachtete A->G Hypermutationsmuster nun auch für LCMV bestätigt werden. Sowohl in vitro in L929-Zellen als auch in vivo in Mäusen wurde eine erhöhte A->G Mutationsfrequenz gefunden, die zwischen 50 und 75 % aller Mutationen in der S-RNA von LCMV ausmacht. Dies zeigte sich vor allem in der späten Phase der Infektion, also zu Beginn der Persistenz. Insgesamt wurden zu diesem Zeitpunkt in L929-Zellen 27 % und in der Maus 15 % nicht funktionelles LCMV-GP synthetisiert. Zudem wurde die Relevanz der A->G Hypermutationen für die beeinträchtigte Funktion des GPs deutlich, da sie 62 % der nicht infektiösen GP-Moleküle verursachen. Die desaminierende Wirkung der iADAR-1 auf das virale Genom von LCMV wurde in 293T-Zellen direkt gezeigt. A->G Mutationen in der S-RNA von LCMV nahmen durch die Überexpression der iADAR-1 in 293T-Zellen um 40 % zu. Ebenso wurde die Replikation bzw. das Assembly von Virionen durch die iADAR-1 reduziert, da im Vergleich zu Kontrollzellen der LCMV-Titer im Überstand von iADAR-1-überexprimierenden Zellen wesentlich niedriger war. Des Weiteren konnte bestätigt werden, dass die A->G Mutationen nicht durch die virale Polymerase induziert werden. Hierfür wurden iADAR-1 „knockout“ murine embryonale Fibroblasten (MEF) isoliert und als stabile Zelllinie etabliert. In diesen Zellen war kein A->G Hypermutationsmuster in der LCMV-RNA zu erkennen. In MEF wt war ebenfalls kein A->G Hypermutationsmuster nachweisbar. Der Grund hierfür könnte die im Vergleich zu L929-Zellen deutlich geringere basale iADAR-1-Expression der nicht völlig ausdifferenzierten MEFs sein
Post-Irradiation Morphea of the Breast in a Patient with Subacute Cutaneous Lupus Erythematosus: Case Report and a Literature Review.
The appearance of morphea after radiotherapy, especially in the context of breast cancer, is a rare but known phenomenon. The incidence of post-irradiation morphea (PIM) of the breast is approximately one in every 500 patients, a higher rate than morphea of any other etiology, which is three per 100,000 per year. PIM usually appears less than 1 year after irradiation (range 1 month to 32 years). The histological pattern of PIM is different from the one in post-irradiation fibrosis, which is a common side effect of radiotherapy and usually appears during the first 3 months after irradiation. Several theories have been proposed to explain the pathogenesis of PIM, probably caused by a disturbance of the cytokine pattern. The development of PIM in patients with autoimmune diseases has been described in the literature. To our knowledge, we report the first case of PIM in a patient with subacute cutaneous lupus erythematosus. We should therefore pay attention when looking at patients with PIM to search for an underlying autoimmune disease
Proneness to decreased negative emotions in major depressive disorder when blaming others rather than oneself
<b><i>Background:</i></b> One widespread view holds that vulnerability to major depressive disorder (MDD) is linked to overall increases in negative emotionality. In contrast, cognitive attribution theories emphasize the importance of blaming oneself rather than others for negative events. Thus far, the contrasting predictions of these models have not been directly compared. Following the attributional perspective, we tested the hypothesis that people with remitted MDD show no overall bias towards negative emotions, but a selective bias towards self-blaming emotions relative to those emotions associated with blaming others. <b><i>Sampling and Methods:</i></b> We compared a remitted MDD and a control group on a novel experimental test that allowed us to directly compare proneness to specific emotions associated with different types of self-blame (guilt, shame, self-contempt/disgust) and blame of others (other-indignation/anger, other-contempt/disgust) whilst controlling for negative valence and medication status, and excluding comorbidity. <b><i>Results:</i></b> In agreement with our hypothesis, individuals with remitted MDD exhibited an increased self-contempt bias (difference between contempt/disgust towards self and others) but no increased proneness to any other negative emotion or overall increases in perceived negative valence of stimuli. Moreover, the remitted MDD group exhibited reduced contempt/disgust towards others. <b><i>Conclusions:</i></b> Our results corroborate the prediction that vulnerability to MDD is associated with an imbalance of specific self- and other-blaming emotions rather than a general increase in negative emotions. Based on the composition of our sample, we speculate that self-contempt bias may be particularly characteristic of melancholic MDD subtypes and could be useful for stratification of depression in the future.</jats:p
Recruiting for research studies using online public advertisements examples from research in affective disorders
Neural responses to facial emotions and subsequent clinical outcomes in difficult-to-treat depression
Background: Amygdala and dorsal anterior cingulate cortex responses to facial emotions have shown promise in predicting treatment response in medication-free major depressive disorder (MDD). Here, we examined their role in the pathophysiology of clinical outcomes in more chronic, difficult-to-treat forms of MDD.Methods: Forty-five people with current MDD who had not responded to ≥2 serotonergic antidepressants (n=42, meeting pre-defined fMRI minimum quality thresholds) were enrolled and followed up over four months of standard primary care. Prior to medication review, subliminal facial emotion fMRI was used to extract blood-oxygen level-dependent effects for sad vs. happy faces from two pre-registered a priori defined regions: bilateral amygdala and dorsal/pregenual anterior cingulate cortex. Clinical outcome was the percentage change on the self-reported Quick Inventory of Depressive Symptomatology (16-item).Results: We corroborated our pre-registered hypothesis (NCT04342299) that lower bilateral amygdala activation for sad vs. happy faces predicted favourable clinical outcomes (rs[38]=.40, p=.01). In contrast, there was no effect for dorsal/pregenual anterior cingulate cortex activation (rs[38]=.18, p=.29), nor when using voxel-based whole-brain analyses (voxel-based Family-Wise Error-corrected p<.05). Predictive effects were mainly driven by the right amygdala whose response to happy faces was reduced in patients with higher anxiety levels.Conclusions: We confirmed the prediction that a lower amygdala response to negative vs. positive facial expressions might be an adaptive neural signature, which predicts subsequent symptom improvement also in difficult-to-treat MDD. Anxiety reduced adaptive amygdala responses
Subgenual activation and the finger of blame: individual differences and depression vulnerability.
BACKGROUND: Subgenual cingulate cortex (SCC) responses to self-blaming emotion-evoking stimuli were previously found in individuals prone to self-blame with and without a history of major depressive disorder (MDD). This suggested SCC activation reflects self-blaming emotions such as guilt, which are central to models of MDD vulnerability. METHOD: Here, we re-examined these hypotheses in an independent larger sample. A total of 109 medication-free participants (70 with remitted MDD and 39 healthy controls) underwent fMRI whilst judging self- and other-blaming emotion-evoking statements. They also completed validated questionnaires of proneness to self-blaming emotions including those related to internal (autonomy) and external (sociotropy) evaluation, which were subjected to factor analysis. RESULTS: An interaction between group (remitted MDD v. Control) and condition (self- v. other-blame) was observed in the right SCC (BA24). This was due to higher SCC signal for self-blame in remitted MDD and higher other-blame-selective activation in Control participants. Across the whole sample, extracted SCC activation cluster averages for self- v. other-blame were predicted by a regression model which included the reliable components derived from our factor analysis of measures of proneness to self-blaming emotions. Interestingly, this prediction was solely driven by autonomy/self-criticism, and adaptive guilt factors, with no effect of sociotropy/dependency. CONCLUSIONS: Despite confirming the prediction of SCC activation in self-blame-prone individuals and those vulnerable to MDD, our results suggest that SCC activation reflects blame irrespective of where it is directed rather than selective for self. We speculate that self-critical individuals have more extended SCC representations for blame in the context of self-agency
Altruistic decisions following penetrating traumatic brain injury
Abstract
The cerebral correlates of altruistic decisions have increasingly attracted the interest of neuroscientists. To date, investigations on the neural underpinnings of altruistic decisions have primarily been conducted in healthy adults undergoing functional neuroimaging as they engaged in decisions to punish third parties. The chief purpose of the present study was to investigate altruistic decisions following focal brain damage with a novel altruistic decision task. In contrast to studies that have focused either on altruistic punishment or donation, the Altruistic Decision Task allows players to anonymously punish or donate to 30 charitable organizations involved with salient societal issues such as abortion, nuclear energy and civil rights. Ninety-four Vietnam War veterans with variable patterns of penetrating traumatic brain injury and 28 healthy veterans who also served in combat participated in the study as normal controls. Participants were asked to invest $1 to punish or reward real societal organizations, or keep the money for themselves. Associations between lesion distribution and performance on the task were analysed with multivariate support vector regression, which enables the assessment of the joint contribution of multiple regions in the determination of a given behaviour of interest. Our main findings were: (i) bilateral dorsomedial prefrontal lesions increased altruistic punishment, whereas lesions of the right perisylvian region and left temporo-insular cortex decreased punishment; (ii) altruistic donations were increased by bilateral lesions of the dorsomedial parietal cortex, whereas lesions of the right posterior superior temporal sulcus and middle temporal gyri decreased donations; (iii) altruistic punishment and donation were only weakly correlated, emphasizing their dissociable neuroanatomical associations; and (iv) altruistic decisions were not related to post-traumatic personality changes. These findings indicate that altruistic punishment and donation are determined by largely non-overlapping cerebral regions, which have previously been implicated in social cognition and moral experience such as evaluations of intentionality and intuitions of justice and morality.
10.1093/brain/awy064_video1 awy064media1 5758316955001</jats:p
A Highly Stable Prefusion Rsv F Vaccine Derived from Structural Analysis of the Fusion Mechanism
Respiratory syncytial virus (RSV) causes acute lower respiratory tract infections and is the leading cause of infant hospitalizations. Recently, a promising vaccine antigen based on the RSV fusion protein (RSV F) stabilized in the native prefusion conformation has been described. Here we report alternative strategies to arrest RSV F in the prefusion conformation based on the prevention of hinge movements in the first refolding region and the elimination of proteolytic exposure of the fusion peptide. A limited number of unique mutations are identified that stabilize the prefusion conformation of RSV F and dramatically increase expression levels. This highly stable prefusion RSV F elicits neutralizing antibodies in cotton rats and induces complete protection against viral challenge. Moreover, the structural and biochemical analysis of the prefusion variants suggests a function for p27, the excised segment that precedes the fusion peptide in the polypeptide chain
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