1,699 research outputs found
On an Analytical Framework for Voids: Their abundances, density profiles and local mass functions
We present a general analytical procedure for computing the number density of
voids with radius above a given value within the context of gravitational
formation of the large scale structure of the universe out of Gaussian initial
conditions. To this end we develop an accurate (under generally satisfied
conditions) extension of unconditional mass function to constrained
environments, which allowes us both to obtain the number density of collapsed
objects of certain mass at any distance from the center of the void, and to
derive the number density of voids defined by those collapsed objects. We have
made detailed calculations for the spherically averaged mass density and halo
number density profiles for individual voids. We also present a formal
expression for the number density of voids defined by galaxies of a given type
and luminosity. This expression contains the probability for a collapsed object
of certain mass to host a galaxy of that type and luminosity as a function of
the environmental density. We propose a procedure to infer this function, which
may provide useful clues as to the galaxy formation process, from the observed
void densities.Comment: 14 pages, 7 figures, MNRAS in pres
Measuring every particle's size from three-dimensional imaging experiments
Often experimentalists study colloidal suspensions that are nominally
monodisperse. In reality these samples have a polydispersity of 4-10%. At the
level of an individual particle, the consequences of this polydispersity are
unknown as it is difficult to measure an individual particle size from
microscopy. We propose a general method to estimate individual particle radii
within a moderately concentrated colloidal suspension observed with confocal
microscopy. We confirm the validity of our method by numerical simulations of
four major systems: random close packing, colloidal gels, nominally
monodisperse dense samples, and nominally binary dense samples. We then apply
our method to experimental data, and demonstrate the utility of this method
with results from four case studies. In the first, we demonstrate that we can
recover the full particle size distribution {\it in situ}. In the second, we
show that accounting for particle size leads to more accurate structural
information in a random close packed sample. In the third, we show that crystal
nucleation occurs in locally monodisperse regions. In the fourth, we show that
particle mobility in a dense sample is correlated to the local volume fraction.Comment: 7 pages, 5 figure
Role of liposome and peptide in the synergistic enhancement of transfection with a lipopolyplex vector
Lipopolyplexes are of widespread interest for gene therapy due to their multifunctionality and high transfection efficiencies. Here we compared the biological and biophysical properties of a lipopolyplex formulation with its lipoplex and polyplex equivalents to assess the role of the lipid and peptide components in the formation and function of the lipopolyplex formulation. We show that peptide efficiently packaged plasmid DNA forming spherical, highly cationic nanocomplexes that are taken up efficiently by cells. However, transgene expression was poor, most likely due to endosomal degradation since the polyplex lacks membrane trafficking properties. In addition the strong peptide-DNA interaction may prevent plasmid release from the complex and so limit plasmid DNA availability. Lipid/DNA lipoplexes, on the other hand, produced aggregated masses that showed poorer cellular uptake than the polyplex but contrastingly greater levels of transgene expression. This may be due to the greater ability of lipoplexes relative to polyplexes to promote endosomal escape. Lipopolyplex formulations formed spherical, cationic nanocomplexes with efficient cellular uptake and significantly enhanced transfection efficiency. The lipopolyplexes combined the optimal features of lipoplexes and polyplexes showing optimal cell uptake, endosomal escape and availability of plasmid for transcription, thus explaining the synergistic increase in transfection efficiency
Comparison of outcomes after UKA in patients with and without chondrocalcinosis: a matched cohort study
Purpose:
Chondrocalcinosis can be associated with an inflammatory arthritis and aggressive joint destruction. There is uncertainty as to whether chondrocalcinosis represents a contraindication to unicompartmental knee arthroplasty (UKA). This study reports the outcome of a consecutive series of patients with chondrocalcinosis and medial compartment osteoarthritis treated with UKA matched to controls.
Methods:
Between 1998 and 2008, 88 patients with radiological chondrocalcinosis (R-CCK) and 67 patients with histological chondrocalcinosis (H-CCK) were treated for end-stage medial compartment arthritis with Oxford UKA. One-to-two matching was performed to controls, treated with UKA, but without evidence of chondrocalcinosis. Functional outcome and implant survival were assessed in each group.
Results:
The mean follow-up was 10 years. The mean Oxford Knee Score (OKS) at final follow-up was 43, 41 and 41 in H-CCK, R-CCK and control groups (change from baseline OKS was 21, 18 and 15, respectively). The change was significantly higher in H-CCK than in control but was not significantly different in R-CCK. Ten-year survival was 96 % in R-CCK, 86 % in H-CCK and 98 % in controls. Although the survival in H-CCK was significantly worse than in control, only one failure was due to disease progression.
Conclusion:
The presence of R-CCK does not influence functional outcome or survival following UKA. Pre-operative radiological evidence of CCK should not be considered to be a contraindication to UKA. H-CCK is associated with significantly improved clinical outcomes but also a higher revision rate compared with controls.
Level of evidence:
Case control study, Level III
Leptogenesis in the presence of exact flavor symmetries
In models with flavor symmetries in the leptonic sector leptogenesis can take
place in a very different way compared to the standard leptogenesis scenario.
We study the generation of a asymmetry in these kind of models in the
flavor symmetric phase pointing out that successful leptogenesis requires (i)
the right-handed neutrinos to lie in different representations of the flavor
group; (ii) the flavons to be lighter at least that one of the right-handed
neutrino representations. When these conditions are satisfied leptogenesis
proceeds due to new contributions to the CP violating asymmetry and -depending
on the specific model- in several stages. We demonstrate the validity of these
arguments by studying in detail the generation of the asymmetry in a
scenario of a concrete flavor model realization.Comment: 25 pages, 7 figures; version 2: A few clarifications added. Version
matches publication in JHE
Binge-watching: Video-on-demand, quality TV and mainstreaming fandom
This article explores the concept of the binge as viewing protocol associated with fan practices, industry practice and linked to ‘cult’ and ‘quality’ serialised content. Viewing binge-watching as an intersection of discourses of industry, audience and text, the concept is analysed here as shaped by a range of issues that dominate the contemporary media landscape. In this, factors like technological developments, fan discourses and practices being adopted as ‘mainstream’ media practice, changes in the discursive construction of ‘television’ and an emerging Video-on-Demand industry contribute to the construction of binge-watching as deliberate, self-scheduled alternative to ‘watching TV’
Tumor innate immunity primed by specific interferon-stimulated endogenous retroviruses.
Mesenchymal tumor subpopulations secrete pro-tumorigenic cytokines and promote treatment resistance1-4. This phenomenon has been implicated in chemorefractory small cell lung cancer and resistance to targeted therapies5-8, but remains incompletely defined. Here, we identify a subclass of endogenous retroviruses (ERVs) that engages innate immune signaling in these cells. Stimulated 3 prime antisense retroviral coding sequences (SPARCS) are oriented inversely in 3' untranslated regions of specific genes enriched for regulation by STAT1 and EZH2. Derepression of these loci results in double-stranded RNA generation following IFN-γ exposure due to bi-directional transcription from the STAT1-activated gene promoter and the 5' long terminal repeat of the antisense ERV. Engagement of MAVS and STING activates downstream TBK1, IRF3, and STAT1 signaling, sustaining a positive feedback loop. SPARCS induction in human tumors is tightly associated with major histocompatibility complex class 1 expression, mesenchymal markers, and downregulation of chromatin modifying enzymes, including EZH2. Analysis of cell lines with high inducible SPARCS expression reveals strong association with an AXL/MET-positive mesenchymal cell state. While SPARCS-high tumors are immune infiltrated, they also exhibit multiple features of an immune-suppressed microenviroment. Together, these data unveil a subclass of ERVs whose derepression triggers pathologic innate immune signaling in cancer, with important implications for cancer immunotherapy
Madness decolonized?: Madness as transnational identity in Gail Hornstein’s Agnes’s Jacket
The US psychologist Gail Hornstein’s monograph Agnes’s Jacket: A Psychologist’s Search for the Meanings of Madness (2009) is an important intervention in the identity politics of the mad movement. Hornstein offers a resignified vision of mad identity that embroiders the central trope of an “anti-colonial” struggle to reclaim the experiential world “colonized” by psychiatry. A series of literal and figurative appeals make recourse to the inner world and (corresponding) cultural world of the mad, as well as to the ethno-symbolic cultural materials of dormant nationhood. This rhetoric is augmented by a model in which the mad comprise a diaspora without an origin, coalescing into a single transnational community. The mad are also depicted as persons displaced from their metaphorical homeland, the “inner” world “colonized” by the psychiatric regime. There are a number of difficulties with Hornstein’s rhetoric, however. Her “ethnicity-and-rights” response to the oppression of the mad is symptomatic of Western parochialism, while her proposed transmutation of putative psychopathology from limit upon identity to parameter of successful identity is open to contestation. Moreover, unless one accepts Hornstein’s porous vision of mad identity, her self-ascribed insider status in relation to the mad community may present a problematic “re-colonization” of mad experience
A song and dance: branded entertainment and mobile promotion
This article considers the rise of branded entertainment within the contemporary marketing and media environment. Specifically, it examines how mobile phone marketing in the UK has sought to engage consumers and perform the social use of mobile technology through multimedia ad campaigns with an inscribed entertainment value. Focusing on brand campaigns for 3G mobile services that borrow explicitly from reality television (T-Mobile) and Hollywood film (Orange), the article explores the concept of branded entertainment in relation to the ‘popular imagination’ of mobile communication in the late 2000s. In doing so, it examines the particular relation of flash mobs to the production of brand community
A Mixed-Methods Approach for Evaluating the Influence of Residential Practices for Thermal Comfort on Electricity Consumption in Auroville, India
With rapid global economic growth and a rise in disposable household income, particularly within a progressively warming planet, the escalating demand for energy to achieve thermal comfort has become a salient concern in the Global South, notably in emerging economies like India. This burgeoning need for cooling solutions has not only underscored the vital role of energy consumption but has also accentuated the imperative of comprehending the ensuing implications for electricity policy and strategic planning, particularly within the ambit of the Global South. This study explored the nuanced landscape of active cooling within an intentional community, Auroville, in southern India, aiming to discern the factors underpinning household preferences and practices in the pursuit of thermal comfort. Employing a mixed-methods approach, this study contributed empirically and methodologically to the interdisciplinary discourse by analysing residential electricity consumption patterns and cooling practices within selected households in the specified community. The study unfolded in three methodological stages: firstly, an analysis of climatic data coupled with an environmental stress index (ESI) assessment; secondly, the monitoring of end-user electricity consumption followed by rigorous data analysis; and lastly, the utilisation of qualitative in-depth interviews and observational techniques. This study’s outcome yielded empirical insights into the unprecedented shifts in the ESI for Auroville since 2014. Furthermore, the study unravelled the intricate complexities inherent in occupant behaviour within residential structures, thereby offering valuable insights into the practices that shape householders’ cooling preferences. This research enriched the understanding of the dynamics of energy consumption in the pursuit of thermal comfort and contributes to the broader discourse on sustainable development and energy policy in the context of climate change
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