339 research outputs found
Collapse and revival of oscillations in a parametrically excited Bose-Einstein condensate in combined harmonic and optical lattice trap
In this work, we study parametric resonances in an elongated cigar-shaped BEC
in a combined harmonic trap and a time dependent optical lattice by using
numerical and analytical techniques. We show that there exists a relative
competition between the harmonic trap which tries to spatially localize the BEC
and the time varying optical lattice which tries to delocalize the BEC. This
competition gives rise to parametric resonances (collapse and revival of the
oscillations of the BEC width). Parametric resonances disappear when one of the
competing factors i.e strength of harmonic trap or the strength of optical
lattice dominates. Parametric instabilities (exponential growth of Bogoliubov
modes) arise for large variations in the strength of the optical lattice.Comment: 9 pages, 20 figure
The selective phosphodiesterase 4 inhibitor roflumilast and phosphodiesterase 3/4 inhibitor pumafentrine reduce clinical score and TNF expression in experimental colitis in mice.
The specific inhibition of phosphodiesterase (PDE)4 and dual inhibition of PDE3 and PDE4 has been shown to decrease inflammation by suppression of pro-inflammatory cytokine synthesis. We examined the effect of roflumilast, a selective PDE4 inhibitor marketed for severe COPD, and the investigational compound pumafentrine, a dual PDE3/PDE4 inhibitor, in the preventive dextran sodium sulfate (DSS)-induced colitis model. The clinical score, colon length, histologic score and colon cytokine production from mice with DSS-induced colitis (3.5% DSS in drinking water for 11 days) receiving either roflumilast (1 or 5 mg/kg body weight/d p.o.) or pumafentrine (1.5 or 5 mg/kg/d p.o.) were determined and compared to vehicle treated control mice. In the pumafentrine-treated animals, splenocytes were analyzed for interferon-γ (IFNγ) production and CD69 expression. Roflumilast treatment resulted in dose-dependent improvements of clinical score (weight loss, stool consistency and bleeding), colon length, and local tumor necrosis factor-α (TNFα) production in the colonic tissue. These findings, however, were not associated with an improvement of the histologic score. Administration of pumafentrine at 5 mg/kg/d alleviated the clinical score, the colon length shortening, and local TNFα production. In vitro stimulated splenocytes after in vivo treatment with pumafentrine showed a significantly lower state of activation and production of IFNγ compared to no treatment in vivo. These series of experiments document the ameliorating effect of roflumilast and pumafentrine on the clinical score and TNF expression of experimental colitis in mice
Dynamical Coupling between a Bose-Einstein Condensate and a Cavity Optical Lattice
A Bose-Einstein condensate is dispersively coupled to a single mode of an
ultra-high finesse optical cavity. The system is governed by strong
interactions between the atomic motion and the light field even at the level of
single quanta. While coherently pumping the cavity mode the condensate is
subject to the cavity optical lattice potential whose depth depends nonlinearly
on the atomic density distribution. We observe bistability already below the
single photon level and strong back-action dynamics which tunes the system
periodically out of resonance.Comment: 5 pages, 4 figure
Challenging school reform from below: is leadership the missing link in mobilization theory?
This article presents research relating to the experiences of union and community-based campaigns that have sought to challenge the establishment of academy and free schools in England. Such schools are removed from local government control and are seen as a defining element of the neoliberal restructuring of public education. The research draws on social-movement literature, and particularly mobilization theory, to better understand the dynamics of such campaigns and the contexts in which they can either thrive or wither. In the article, I argue that mobilization theory provides a useful framework for such analysis but that it fails to adequately reflect the importance of individual agency and the role of leadership at a local level. Leadership of such campaigns is often assumed by individuals reluctantly, and often defies traditional descriptions of “leadership,” but must be recognized if mobilization theory is to avoid being overly deterministic
Organogenesis and embryogenesis in several hypericum perforatum genotypes
St John’s wort (Hypericum perforatum) is a valuable plant used as a herbal remedy or in phytopharmaceutical drugs to
treat a variety of physical ailments. Much research has been performed to study the biochemical production of secondary
metabolites of in vitro cultured plants or organs. However, all of these studies have looked at the regeneration of plants
from explants in only one genotype. In addition, no study has revealed the mechanism of plant regeneration in
H. perforatum, i.e. organogenesis or somatic embryogenesis. We found that different genotypes Helos, Topas, Elixir, and
Numi responded similarly to regeneration medium. The regeneration responses (i.e. callus, root, or shoot production) of
identical explants from different genotypes were similar. However, the source of explant material (leaves, hypocotyls, and
roots) from the same genotype had significant effects on the response to media and plant regeneration frequency. Using
scanning electron microscopy and light microscopy, the progress of organogenesis and embryogenesis under similar
culture conditions was recorded. Root segments were the most responsive explants, producing the maximum number of
shoots per explant of all the genotypes.Fundação para a Ciência e a Tecnologia (FCT) -
POCTI/AGR/40 283/2001, SFRH/BPD/17102/2004
Malnutrition enteropathy in Zambian and Zimbabwean children with severe acute malnutrition: A multi-arm randomized phase II trial.
Malnutrition underlies almost half of all child deaths globally. Severe Acute Malnutrition (SAM) carries unacceptable mortality, particularly if accompanied by infection or medical complications, including enteropathy. We evaluated four interventions for malnutrition enteropathy in a multi-centre phase II multi-arm trial in Zambia and Zimbabwe and completed in 2021. The purpose of this trial was to identify therapies which could be taken forward into phase III trials. Children of either sex were eligible for inclusion if aged 6-59 months and hospitalised with SAM (using WHO definitions: WLZ <-3, and/or MUAC <11.5 cm, and/or bilateral pedal oedema), with written, informed consent from the primary caregiver. We randomised 125 children hospitalised with complicated SAM to 14 days treatment with (i) bovine colostrum (n = 25), (ii) N-acetyl glucosamine (n = 24), (iii) subcutaneous teduglutide (n = 26), (iv) budesonide (n = 25) or (v) standard care only (n = 25). The primary endpoint was a composite of faecal biomarkers (myeloperoxidase, neopterin, α1-antitrypsin). Laboratory assessments, but not treatments, were blinded. Per-protocol analysis used ANCOVA, adjusted for baseline biomarker value, sex, oedema, HIV status, diarrhoea, weight-for-length Z-score, and study site, with pre-specified significance of P < 0.10. Of 143 children screened, 125 were randomised. Teduglutide reduced the primary endpoint of biomarkers of mucosal damage (effect size -0.89 (90% CI: -1.69,-0.10) P = 0.07), while colostrum (-0.58 (-1.4, 0.23) P = 0.24), N-acetyl glucosamine (-0.20 (-1.01, 0.60) P = 0.67), and budesonide (-0.50 (-1.33, 0.33) P = 0.32) had no significant effect. All interventions proved safe. This work suggests that treatment of enteropathy may be beneficial in children with complicated malnutrition. The trial was registered at ClinicalTrials.gov with the identifier NCT03716115
A window on reality: perceiving edited moving images
Edited moving images entertain, inform, and coerce us throughout our daily lives, yet until recently, the way people perceive movies has received little psychological attention. We review the history of empirical investigations into movie perception and the recent explosion of new research on the subject using methods such as behavioral experiments, functional magnetic resonance imagery (fMRI) eye tracking, and statistical corpus analysis. The Hollywood style of moviemaking, which permeates a wide range of visual media, has evolved formal conventions that are compatible with the natural dynamics of attention and humans’ assumptions about continuity of space, time, and action. Identifying how people overcome the sensory differences between movies and reality provides an insight into how the same cognitive processes are used to perceive continuity in the real world
Match-action: the role of motion and audio in creating global change blindness in film
An everyday example of change blindness is our difficulty to detect cuts in an edited moving-image. Edit Blindness (Smith & Henderson, 2008) is created by adhering to the continuity editing conventions of Hollywood, e.g. coinciding a cut with a sudden onset of motion (Match-Action). In this study we isolated the roles motion and audio play in limiting awareness of match-action cuts by removing motion before and/or after cuts in existing Hollywood film clips and presenting the clips with or without the original soundtrack whilst participants tried to detect cuts. Removing post-cut motion significantly decreased cut detection time and the probability of missing the cut. By comparison, removing pre-cut motion had no effect suggesting, contrary to the editing literature, that the onset of motion before a cut may not be as critical for creating edit blindness as the motion after a cut. Analysis of eye movements indicated that viewers reoriented less to new content across intact match-action cuts than shots with motion removed. Audio played a surprisingly large part in creating edit blindness with edit blindness mostly disappearing without audio. These results extend film editor intuitions and are discussed in the context of the Attentional Theory of Cinematic Continuity (Smith, 2012a)
Mesalazine in the initial management of severely acutely malnourished children with environmental enteric dysfunction: a pilot randomized controlled trial
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