1,737 research outputs found
Super-Razor and Searches for Sleptons and Charginos at the LHC
Direct searches for electroweak pair production of new particles at the LHC
are a difficult proposition, due to the large background and low signal cross
sections. We demonstrate how these searches can be improved by a combination of
new razor variables and shape analysis of signal and background kinematics. We
assume that the pair-produced particles decay to charged leptons and missing
energy, either directly or through a W boson. In both cases the final state is
a pair of opposite sign leptons plus missing transverse energy. We estimate
exclusion reach in terms of sleptons and charginos as realized in minimal
supersymmetry. We compare this super-razor approach in detail to analyses based
on other kinematic variables, showing how the super-razor uses more of the
relevant kinematic information while achieving higher selection efficiency on
signals, including cases with compressed spectra.Comment: 33 pages, 33 figure
Why does chronic inflammation persist: An unexpected role for fibroblasts
One of the most important but as yet unanswered questions in inflammation research is not why inflammation occurs (we all get episodes of self limiting inflammation during the course of our lives) but why it does not resolve. Current models of inflammation stress the role of antigen-specific lymphocyte responses and attempt to address the causative agent. However, recent studies have begun to challenge the primacy of the leukocyte and have instead focused on an extended immune system in which stromal cells, such as fibroblasts play a role in the persistence of the inflammatory lesion. In this review I will illustrate how fibroblasts help regulate the switch from acute resolving to chronic persistent inflammation and provide positional memory during inflammatory responses. In chronic inflammation the normal physiological process of the removal of unwanted inflammatory effector cells becomes disordered, leading to the accumulation of leucocytes within lymphoid aggregates that resemble those seen in lymphoid tissue. I will describe how fibroblasts provide survival and retention signals for leukocytes leading to their inappropriate and persistent accumulation within inflamed tissue
Patient and researcher perspectives on facilitating patient and public involvement in rheumatology research
No abstract available
Moving beyond convergence in the pheromone system of the moth
No description supplie
Distinct Types of Fibrocyte Can Differentiate from Mononuclear Cells in the Presence and Absence of Serum
Background: Ageing, immunity and stresstolerance are inherent characteristics of all organisms. In animals, these traits are regulated, at least in part, by forkhead transcription factors in response to upstream signals from the Insulin/Insulin–like growth factor signalling (IIS) pathway. In the nematode Caenorhabditis elegans, these phenotypes are molecularly linked such that activation of the forkhead transcription factor DAF-16 both extends lifespan and simultaneously increases immunity and stress resistance. It is known that lifespan varies significantly among the Caenorhabditis species but, although DAF-16 signalling is highly conserved, it is unclear whether this phenotypic linkage occurs in other species. Here we investigate this phenotypic covariance by comparing longevity, stress resistance and immunity in four Caenorhabditis species.
Methodology/Principal Findings: We show using phenotypic analysis of DAF-16 influenced phenotypes that among four closely related Caenorhabditis nematodes, the gonochoristic species (Caenorhabditis remanei and Caenorhabditis brenneri) have diverged significantly with a longer lifespan, improved stress resistance and higher immunity than the hermaphroditic species (C. elegans and Caenorhabditis briggsae). Interestingly, we also observe significant differences in expression levels between the daf-16 homologues in these species using Real-Time PCR, which positively correlate with the observed phenotypes. Finally, we provide additional evidence in support of a role for DAF-16 in regulating phenotypic coupling by using a combination of wildtype isolates, constitutively active daf-16 mutants and bioinformatic analysis.
Conclusions: The gonochoristic species display a significantly longer lifespan (p<0.0001) and more robust immune and stress response (p<0.0001, thermal stress; p<0.01, heavy metal stress; p<0.0001, pathogenic stress) than the hermaphroditic species. Our data suggests that divergence in DAF-16 mediated phenotypes may underlie many of the differences observed between these four species of Caenorhabditis nematodes. These findings are further supported by the correlative higher daf-16 expression levels among the gonochoristic species and significantly higher lifespan, immunity and stress tolerance in the constitutively active daf-16 hermaphroditic mutants
Fibroblast heterogeneity: keystone of tissue homeostasis and pathology in inflammation and ageing
Fibroblasts, derived from the embryonic mesenchyme, are a diverse array of cells with roles in development, homeostasis, repair, and disease across tissues. In doing so, fibroblasts maintain micro-environmental homeostasis and create tissue niches by producing a complex extracellular matrix (ECM) including various structural proteins. Although long considered phenotypically homogenous and functionally identical, the emergence of novel technologies such as single cell transcriptomics has allowed the identification of different phenotypic and cellular states to be attributed to fibroblasts, highlighting their role in tissue regulation and inflammation. Therefore, fibroblasts are now recognised as central actors in many diseases, increasing the need to discover new therapies targeting those cells. Herein, we review the phenotypic heterogeneity and functionality of these cells and their roles in health and disease
Resolution of inflammation:state of the art, definitions and terms
A recent focus meeting on Controlling Acute Inflammation was held in London, April 27-28, 2006, organized by D.W. Gilroy and S.D. Brain for the British Pharmacology Society. We concluded at the meeting that a consensus report was needed that addresses the rapid progress in this emerging field and details how the specific study of resolution of acute inflammation provides leads for novel anti-inflammatory therapeutics, as well as defines the terms and key components of interest in the resolution process within tissues as appreciated today. The inflammatory response protects the body against infection and injury but can itself become dysregulated with deleterious consequences to the host. It is now evident that endogenous biochemical pathways activated during defense reactions can counter-regulate inflammation and promote resolution. Hence, resolution is an active rather than a passive process, as once believed, which now promises novel approaches for the treatment of inflammation-associated diseases based on endogenous agonists of resolution
Sub-Antarctic and High Antarctic Notothenioid Fishes: Ecology and Adaptational Biology Revealed by the ICEFISH 2004 Cruise of RVIB Nathaniel B. Palmer
The goal of the ICEFISH 2004 cruise, which was conducted on board RVIB Nathaniel B. Palmer and traversed the transitional zones linking the South Atlantic to the Southern Ocean, was to compare the evolution, ecology, adaptational biology, community structure, and population dynamics of Antarctic notothenioid fishes relative to the cool/temperate notothenioids of the sub-Antarctic. To place this work in a comprehensive ecological context, cruise participants surveyed the benthos and geology of the biogeographic provinces and island shelves on either side of the Antarctic Polar Front (or Antarctic Convergence). Genome-enabled comparison of the responses of cold-living and temperate notothenioids to heat stress confirmed the sensitivity of the former to a warming Southern Ocean. Successful implementation of the international and interdisciplinary ICEFISH research cruise provides a model for future exploration of the sub-Antarctic sectors of the Indian and Pacific Oceans
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