3,762 research outputs found
Repeated stressors in adulthood increase the rate of biological ageing
Background
Individuals of the same age can differ substantially in the degree to which they have accumulated tissue damage, akin to bodily wear and tear, from past experiences. This accumulated tissue damage reflects the individual’s biological age and may better predict physiological and behavioural performance than the individual‘s chronological age. However, at present it remains unclear how to reliably assess biological age in individual wild vertebrates.
Methods
We exposed hand-raised adult Eurasian blackbirds (Turdus merula) to a combination of repeated immune and disturbance stressors for over one year to determine the effects of chronic stress on potential biomarkers of biological ageing including telomere shortening, oxidative stress load, and glucocorticoid hormones. We also assessed general measures of individual condition including body mass and locomotor activity.
Results
By the end of the experiment, stress-exposed birds showed greater decreases in telomere lengths. Stress-exposed birds also maintained higher circulating levels of oxidative damage compared with control birds. Other potential biomarkers such as concentrations of antioxidants and glucocorticoid hormone traits showed greater resilience and did not differ significantly between treatment groups.
Conclusions
The current data demonstrate that repeated exposure to experimental stressors affects the rate of biological ageing in adult Eurasian blackbirds. Both telomeres and oxidative damage were affected by repeated stress exposure and thus can serve as blood-derived biomarkers of biological ageing.</p
Dying Dyons Don't Count
The dyonic 1/4-BPS states in 4D string theory with N=4 spacetime
supersymmetry are counted by a Siegel modular form. The pole structure of the
modular form leads to a contour dependence in the counting formula obscuring
its duality invariance. We exhibit the relation between this ambiguity and the
(dis-)appearance of bound states of 1/2-BPS configurations. Using this insight
we propose a precise moduli-dependent contour prescription for the counting
formula. We then show that the degeneracies are duality-invariant and are
correctly adjusted at the walls of marginal stability to account for the
(dis-)appearance of the two-centered bound states. Especially, for large black
holes none of these bound states exists at the attractor point and none of
these ambiguous poles contributes to the counting formula. Using this fact we
also propose a second, moduli-independent contour which counts the "immortal
dyons" that are stable everywhere.Comment: 27 pages, 2 figures; one minus sign correcte
Decolonialidade em Quadrinhos: uma visão afrofuturista de Contos do Orixás
Propõe-se o Afrofuturismo como chave de leitura para apontar Contos dos Orixás, de Hugo Canuto como uma expressão decolonial. A publicação assimila um elemento cultural – o estilo do quadrinista Jack Kirby – para desenhar a mitologia dos orixás numa perspectiva brasileira da cultura Yorùbá. A metodologia aplica o “cruzo” de Simas e Rufino para articular Afrofuturismo, Design e Estudos Culturais numa análise que lida com conhecimentos provenientes do que Grosfoguel compreende como o lado subalternizado da diferença colonial. Conclui-se que a iconografia Yorùbá foi atualizada no cruzo com o design futurista de Kirby a partir de elementos afro-brasileiros.Afrofuturism is proposed as a reading key to point out Contos dos Orixás, by Hugo Canuto as a decolonial expression. The publication assimilates a cultural element – the style of comic artist Jack Kirby – to draw the mythology of the orixás from a Brazilian perspective of Yorùbá culture. The methodology applies Simas’ and Rufino’s “cruzo” to articulate Afrofuturism, Design, and Cultural Studies in an analysis that deals with knowledge from what Grosfoguel understands as the subalternized side of the colonial difference. It is concluded that Yorùbá iconography was updated in the cruzo with Kirby’s futuristic design from Afro-Brazilian elements.El afrofuturismo se propone como clave de lectura para señalar Contos dos Orixás, de Hugo Canuto como expresión decolonial. La publicación asimila un elemento cultural – el estilo del dibujante de cómics Jack Kirby – para dibujar la mitología de los orixás en una perspectiva brasileña de la cultura Yorùbá. La metodología aplica el “cruzo” de Simas y Rufino para articular Afrofuturismo, Diseño y Estudios Culturales en un análisis que aborda el conocimiento desde lo que Grosfoguel entiende como el lado subalternizado de la diferencia colonial. Se concluye que la iconografía Yorùbá fue actualizada en el cruzo con el diseño futurista de Kirby a partir de elementos afrobrasileños.info:eu-repo/semantics/publishedVersio
Physical-mechanical properties of a granite used in the UNESCO World Heritage of the north of Portugal after high-temperature pretreatment
This paper studies the evolution of physical and mechanical properties of 46 cubic
samples of a granite widely used in the UNESCO World Heritage of the north of Portugal pre-treated
at different temperatures (between 105 and 700 °C) and cooled under different conditions (i.e., aircooled
and water-cooled). The results showed that specific gravity and mineralogy did not exhibit
significant changes after the thermal pre-treatment. In contrast, density, porosity, ultrasonic
properties, uniaxial compressive strength and elastic modulus showed important variations, mainly
at temperatures higher than 500 ºC. The SEM analyses clearly show an increase in the density of
cracks, as well as in the width and length of the cracks from 500 ºC. Furthermore, it was observed an
amplification of the damage in those samples cooled by water immersion. These results are of
relevance for the evaluation of the integrity level of buildings built using this rock after a fire.This work was partially funded by the University of Alicante (UAUSTI18-21, UAUSTI19-25 and UAUSTI20-20 projects), the Regional Governments of Comunidad Valenciana AICO/2020/175 and CIAICO/2021/335, the Spanish Ministry of Economy and Competitiveness (MINECO) and EU FEDER under Project TEC2017-85244-C2-1-P, and the Spanish Ministry of Education, Culture and Sport under project CAS17/00392. The authors also want to thank Idael F. Blanco of the Departamento de Ciencias de la Tierra de la Universidad de Alicante for the petrographic description of the thin section
Differentiating the Cognitive Profile of Schizophrenia from That of Alzheimer Disease and Depression in Late Life
To compare the cognitive profile of older patients with schizophrenia to those with other neuropsychiatric disorders assessed in a hospital-based memory clinic.Demographic, clinical, and cognitive data of all patients referred to the memory clinic at the Centre for Addiction and Mental Health between April 1, 2006 and August 15, 2008 were reviewed. We then identified four groups of older patients with: (1) late-life schizophrenia (LLS) and no dementia or depression (DEP); (2) Alzheimer's disease (AD); (3) DEP and no dementia or LLS; (4) normal cognition (NC) and no DEP or LLS.The four groups did not differ in demographic data except that patients with AD were about 12 years older than those with LLS. However, they differed on cognitive tests even after controlling for age. Patients with LLS were impaired on most cognitive tests in comparison with patients with NC but not on recalling newly learned verbal information at a short delay. They experienced equivalent performance on learning new verbal information in comparison with patients with AD, but better performance on all other tests of memory, including the ability to recall newly learned verbal information. Finally, they were more impaired than patients with DEP in overall memory.Patients with LLS have a different cognitive profile than patients with AD or DEP. Particularly, memory impairment in LLS seems to be more pronounced in learning than recall. These findings suggest that cognitive and psychosocial interventions designed to compensate for learning deficits may be beneficial in LLS
Case Study of Resilient Baton Rouge: Applying Depression Collaborative Care and Community Planning to Disaster Recovery.
BackgroundAddressing behavioral health impacts of major disasters is a priority of increasing national attention, but there are limited examples of implementation strategies to guide new disaster responses. We provide a case study of an effort being applied in response to the 2016 Great Flood in Baton Rouge.MethodsResilient Baton Rouge was designed to support recovery after major flooding by building local capacity to implement an expanded model of depression collaborative care for adults, coupled with identifying and responding to local priorities and assets for recovery. For a descriptive, initial evaluation, we coupled analysis of documents and process notes with descriptive surveys of participants in initial training and orientation, including preliminary comparisons among licensed and non-licensed participants to identify training priorities.ResultsWe expanded local behavioral health service delivery capacity through subgrants to four agencies, provision of training tailored to licensed and non-licensed providers and development of advisory councils and partnerships with grassroots and government agencies. We also undertook initial efforts to enhance national collaboration around post-disaster resilience.ConclusionOur partnered processes and lessons learned may be applicable to other communities that aim to promote resilience, as well as planning for and responding to post-disaster behavioral health needs
Minimizing the Ground Effect for Photophoretically Levitating Disks
Photophoretic levitation is a propulsion mechanism in which lightweight
objects can be lifted and controlled through their interactions with light.
Since photophoretic forces on macroscopic objects are usually maximized at low
pressures, they may be tested in vacuum chambers in close proximity to the
chamber floor and walls. We report here experimental evidence that the terrain
under levitating microflyers, including the chamber floor or the launchpad from
which microflyers lift off, can greatly increase the photophoretic lift forces
relative to their free-space (mid-air) values. To characterize this so-called
"ground effect" during vacuum chamber tests, we introduced a new miniature
launchpad composed of three J-shaped (candy-cane-like) wires that minimized a
microflyer's extraneous interactions with underlying surfaces. We compared our
new launchpads to previously used wire-mesh launchpads for simple levitating
mylar-based disks with diameters of 2, 4, and 8 cm. Importantly, wire-mesh
launchpads increased the photophoretic lift force by up to sixfold. A
significant ground effect was also associated with the bottom of the vacuum
chamber, particularly when the distance to the bottom surface was less than the
diameter of the levitating disk. We provide guidelines to minimize the ground
effect in vacuum chamber experiments, which are necessary to test photophoretic
microflyers intended for high-altitude exploration and surveillance on Earth or
on Mars.Comment: 7 pages, 7 figures, including the Supplemental Materia
Intracellular Trafficking and Persistence of Acinetobacter baumannii Requires Transcription Factor EB
Acinetobacter baumannii is a significant human pathogen associated with hospital-acquired infections. While adhesion, an initial and important step in A. baumannii infection, is well characterized, the intracellular trafficking of this pathogen inside host cells remains poorly studied. Here, we demonstrate that transcription factor EB (TFEB) is activated after A. baumannii infection of human lung epithelial cells (A549). We also show that TFEB is required for the invasion and persistence inside A549 cells. Consequently, lysosomal biogenesis and autophagy activation were observed after TFEB activation which could increase the death of A549 cells. In addition, using the Caenorhabditis elegans infection model by A. baumannii, the TFEB orthologue HLH-30 was required for survival of the nematode to infection, although nuclear translocation of HLH-30 was not required. These results identify TFEB as a conserved key factor in the pathogenesis of A. baumannii.Consejería de Innovación, Ciencia y EmpresaInstituto de Salud Carlos IIIMinisterio de Economía, Industria y Competitividad. Subdirección General de Redes y Centros de Investigación CooperativaSpanish Ministry of Economy and Competitivenes
Leukotriene antagonists as first-line or add-on asthma controller therapy
Most randomized trials of treatment for asthma study highly selected patients under idealized conditions. METHODS: We conducted two parallel, multicenter, pragmatic trials to evaluate the real-world effectiveness of a leukotriene-receptor antagonist (LTRA) as compared with either an inhaled glucocorticoid for first-line asthma-controller therapy or a long-acting beta(2)-agonist (LABA) as add-on therapy in patients already receiving inhaled glucocorticoid therapy. Eligible primary care patients 12 to 80 years of age had impaired asthma-related quality of life (Mini Asthma Quality of Life Questionnaire [MiniAQLQ] score =6) or inadequate asthma control (Asthma Control Questionnaire [ACQ] score =1). We randomly assigned patients to 2 years of open-label therapy, under the care of their usual physician, with LTRA (148 patients) or an inhaled glucocorticoid (158 patients) in the first-line controller therapy trial and LTRA (170 patients) or LABA (182 patients) added to an inhaled glucocorticoid in the add-on therapy trial. RESULTS: Mean MiniAQLQ scores increased by 0.8 to 1.0 point over a period of 2 years in both trials. At 2 months, differences in the MiniAQLQ scores between the two treatment groups met our definition of equivalence (95% confidence interval [CI] for an adjusted mean difference, -0.3 to 0.3). At 2 years, mean MiniAQLQ scores approached equivalence, with an adjusted mean difference between treatment groups of -0.11 (95% CI, -0.35 to 0.13) in the first-line controller therapy trial and of -0.11 (95% CI, -0.32 to 0.11) in the add-on therapy trial. Exacerbation rates and ACQ scores did not differ significantly between the two groups. CONCLUSIONS: Study results at 2 months suggest that LTRA was equivalent to an inhaled glucocorticoid as first-line controller therapy and to LABA as add-on therapy for diverse primary care patients. Equivalence was not proved at 2 years. The interpretation of results of pragmatic research may be limited by the crossover between treatment groups and lack of a placebo group
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