137 research outputs found
Towards a Functional Approach to the Assessment of Daily Life Physical Activity in Children: Are the PAQ-C and Fitbit Flex-2 Technically Adequate?
Considering the need for functional physical activity (PA) measures in PA settings, this study sought to determine the technical adequacy of the Physical Activity Questionnaire for Older Children (PAQ-C) and the Fitbit Flex-2, two instruments with promising features for wide use, using the Actigraph GT3X+ accelerometer as the criterion reference. A total of 218 Greek children (94 boys, 124 girls; mean age = 10.99 ± 1.52 years) volunteered to join in. Participants wore the PA trackers for seven days and completed the PAQ-C. Moreover, a sub-group (n = 60) recompleted the PAQ-C after a week. Results revealed acceptable internal consistency and excellent test–retest reliability for the PAQ-C. Regarding concurrent validity, weak to moderate correlations with PA parameters recorded by the GT3X+ were revealed for the total PAQ-C and were excellent for the Flex-2, while a Bland–Altman plot indicated good agreement. Finally, in alignment with relevant literature, significant gender, but no age, differences were found in participants’ PA records in all the tools applied. The above results support the use of the PAQ-C and the Fitbit Flex-2 in children. Considering that they shed light into different parameters of children’s habitual PA, their combined utilisation, providing comprehensive information, is strongly recommended.This research was supported by the European Union’s HORIZON 2020 Programme (2014–2020) under ID n 777082,
and by the Brazilian Ministry of Science, Technology and Innovation through Rede Nacional de Ensino e Pesquisa (RNP) under Ocariot
The Low Surface Brightness Extent of the Fornax Cluster
We have used a large format CCD camera to survey the nearby Fornax cluster
and its immediate environment for low luminosity low surface brightness
galaxies. Recent observations indicate that these are the most dark matter
dominated galaxies known and so they are likely to be a good tracer of the dark
matter in clusters. We have identified large numbers of these galaxies
consistent with a steep faint end slope of the luminosity function (alpha~ -2)
down to MB ~ -12. These galaxies contribute almost the same amount to the total
cluster light as the brighter galaxies and they have a spatial extent that is
some four times larger. They satisfy two of the important predictions of N-body
hierarchical simulations of structure formation using dark halos. The
luminosity (mass ?) function is steep and the mass distribution is more
extended than that defined by the brighter galaxies. We also find a large
concentration of low surface brightness galaxies around the nearby galaxy
NGC1291.Comment: 16 pages, 6 figure
Gas Rich Galaxies and the HI Mass Function
We have developed an automated cross-correlation technique to detect 21cm
emission in sample spectra obtained from the HI Parkes All Sky Survey.
The initial sample selection was the nearest spectra to 2435 low surface
brightness galaxies in the catalogue of Morshidi-Esslinger et al. (1999).
The galaxies were originally selected to have properties similar to Fornax
cluster dE galaxies. As dE galaxies are generally gas poor it is not surprising
that there were only 26 secure detections. All of the detected galaxies have
very high values of . Thus the HI selection of faint
optical sources leads to the detection of predominately gas rich galaxies. The
gas rich galaxies tend to reside on the outskirts of the large scale structure
delineated by optically selected galaxies, but they do appear to be associated
with it. These objects appear to have similar relative dark matter content to
optically selected galaxies. The HI column densities are lower than the
'critical density' necessary for sustainable star formation and they appear,
relatively, rather isolated from companion galaxies. These two factors may
explain their high relative gas content. We have considered the HI mass
function by looking at the distribution of velocities of HI detections in
random spectra on the sky.
The inferred HI mass function is steep though confirmation of this results
awaits a detailed study of the noise characteristics of the HI survey.Comment: MNRAS in pres
The orbital velocity anisotropy of cluster galaxies: evolution
In nearby clusters early-type galaxies follow isotropic orbits, while the
orbits of late-type galaxies are characterized by slightly radial anisotropy.
Little is known about the orbits of the different populations of cluster
galaxies at redshift above z~0.3. Here we investigate the redshift evolution of
the orbits of cluster galaxies using two samples of galaxy clusters spanning
similar (evolutionary corrected) mass ranges at different redshifts. The
low-redshift (z~0.0-0.1) sample is extracted from the ENACS catalog and the
high-redshift (z~0.4-0.8) sample is mostly made of clusters from the EDisCS.
For each of these samples, we solve the Jeans equation for hydrostatic
equilibrium separately for two cluster galaxy populations, characterized by the
presence and, respectively, absence of emission-lines in their spectra ('ELGs'
and 'nELGs' hereafter). Using two tracers of the gravitational potential allows
to partially break the well known mass-velocity anisotropy degeneracy.
We find no significant evolution for the orbits of ELGs. On the other hand
the orbits of nELGs do evolve, from radial to isotropic with time. We speculate
that this evolution may be driven by the secular mass growth of galaxy clusters
during their fast accretion phase. The mass density profiles of the clusters
are well fit by NFW models both in the low-z and in the high-z samples. The
best-fit NFW concentrations and their redshift evolution are in agreement with
the predictions of Lambda CDM cosmological simulations. The evolution of the
number density profile of nELGs is opposite to that of the mass density
profile, becoming less concentrated with time, probably a result of the
transformation of ELGs into nELGs [abridged].Comment: 9 pages, 5 figures. Astr. Ap., 501, 419. Corrected typos in abstract
wrt previous versio
Neutrophil Extracellular Traps in Breast Cancer and Beyond: Current Perspectives on NET Stimuli, Thrombosis and Metastasis, and Clinical Utility for Diagnosis and Treatment
Abstract
The formation of neutrophil extracellular traps (NETs), known as NETosis, was first observed as a novel immune response to bacterial infection, but has since been found to occur abnormally in a variety of other inflammatory disease states including cancer. Breast cancer is the most commonly diagnosed malignancy in women. In breast cancer, NETosis has been linked to increased disease progression, metastasis, and complications such as venous thromboembolism. NET-targeted therapies have shown success in preclinical cancer models and may prove valuable clinical targets in slowing or halting tumor progression in breast cancer patients. We will briefly outline the mechanisms by which NETs may form in the tumor microenvironment and circulation, including the crosstalk between neutrophils, tumor cells, endothelial cells, and platelets as well as the role of cancer-associated extracellular vesicles in modulating neutrophil behavior and NET extrusion. The prognostic implications of cancer-associated NETosis will be explored in addition to development of novel therapeutics aimed at targeting NET interactions to improve outcomes in patients with breast cancer
Thrombosis in vasculitis: from pathogenesis to treatment
In recent years, the relationship between inflammation and thrombosis has been deeply investigated and it is now clear that immune and coagulation systems are functionally interconnected. Inflammation-induced thrombosis is by now considered a feature not only of autoimmune rheumatic diseases, but also of systemic vasculitides such as Behçet’s syndrome, ANCA-associated vasculitis or giant cells arteritis, especially during active disease. These findings have important consequences in terms of management and treatment. Indeed, Behçet’syndrome requires immunosuppressive agents for vascular involvement rather than anticoagulation or antiplatelet therapy, and it is conceivable that also in ANCA-associated vasculitis or large vessel-vasculitis an aggressive anti-inflammatory treatment during active disease could reduce the risk of thrombotic events in early stages. In this review we discuss thrombosis in vasculitides, especially in Behçet’s syndrome, ANCA-associated vasculitis and large-vessel vasculitis, and provide pathogenetic and clinical clues for the different specialists involved in the care of these patients
Uncovering the multifaceted roles played by neutrophils in allogeneic hematopoietic stem cell transplantation
Allogeneic hematopoietic stem cell transplantation (alloHSCT) is a life-saving procedure used for the treatment of selected hematological malignancies, inborn errors of metabolism, and bone marrow failures. The role of neutrophils in alloHSCT has been traditionally evaluated only in the context of their ability to act as a first line of defense against infection. However, recent evidence has highlighted neutrophils as key effectors of innate and adaptive immune responses through a wide array of newly discovered functions. Accordingly, neutrophils are emerging as highly versatile cells that are able to acquire different, often opposite, functional capacities depending on the microenvironment and their differentiation status. Herein, we review the current knowledge on the multiple functions that neutrophils exhibit through the different stages of alloHSCT, from the hematopoietic stem cell (HSC) mobilization in the donor to the immunological reconstitution that occurs in the recipient following HSC infusion. We also discuss the influence exerted on neutrophils by the immunosuppressive drugs delivered in the course of alloHSCT as part of graft-versus-host disease (GVHD) prophylaxis. Finally, the potential involvement of neutrophils in alloHSCT-related complications, such as transplant-associated thrombotic microangiopathy (TA-TMA), acute and chronic GVHD, and cytomegalovirus (CMV) reactivation, is also discussed. Based on the data reviewed herein, the role played by neutrophils in alloHSCT is far greater than a simple antimicrobial role. However, much remains to be investigated in terms of the potential functions that neutrophils might exert during a highly complex procedure such as alloHSCT
Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)
In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. For example, a key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process versus those that measure fl ux through the autophagy pathway (i.e., the complete process including the amount and rate of cargo sequestered and degraded). In particular, a block in macroautophagy that results in autophagosome accumulation must be differentiated from stimuli that increase autophagic activity, defi ned as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (inmost higher eukaryotes and some protists such as Dictyostelium ) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the fi eld understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. It is worth emphasizing here that lysosomal digestion is a stage of autophagy and evaluating its competence is a crucial part of the evaluation of autophagic flux, or complete autophagy. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. Along these lines, because of the potential for pleiotropic effects due to blocking autophagy through genetic manipulation it is imperative to delete or knock down more than one autophagy-related gene. In addition, some individual Atg proteins, or groups of proteins, are involved in other cellular pathways so not all Atg proteins can be used as a specific marker for an autophagic process. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field
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