465 research outputs found
Analyzing a Bose polaron across resonant interactions
Recently, two independent experiments reported the observation of long-lived
polarons in a Bose-Einstein condensate, providing an excellent setting to study
the generic scenario of a mobile impurity interacting with a quantum reservoir.
Here, we expand the experimental analysis by disentangling the effects of trap
inhomogeneities and the many-body continuum in one of these experiments. This
makes it possible to extract the energy of the polaron at a well-defined
density as a function of the interaction strength. Comparisons with quantum
Monte-Carlo as well as diagrammatic calculations show good agreement, and
provide a more detailed picture of the polaron properties at stronger
interactions than previously possible. Moreover, we develop a semi-classical
theory for the motional dynamics and three-body loss of the polarons, which
partly explains a previously unresolved discrepancy between theory and
experimental observations for repulsive interactions. Finally, we utilize
quantum Monte-Carlo calculations to demonstrate that the findings reported in
the two experiments are consistent with each other
Exercise-induced respiratory symptoms are not always asthma
AbstractEighty-eight patients with a history of exercise-induced respiratory symptoms performed a maximal exercise test in order to study the reasons for stopping the test. There was a wide range of percentage maximal fall in peak expiratory flow (PEF), from minus 3% to 63%, mean 11%, recorded 0–30 min, mean 12 min after the break. In the controls the maximal decrease was 0–16%, mean 6%. Diagnostic criteria for asthma were fulfilled by 48 patients (55%). Of these patients 42% had a fall in PEF ≥ 15% (exercise-induced asthma). Of the non-asthma patients 10% had a fall ≥ 15%. The most common reason for stopping the exercise in the asthma group was breathing troubles (46%), the most common reason in the non-asthma group was chest pain/discomfort (35%). In about 20% of the patients dizziness and/or pricking sensations in arms or legs indicated hyperventilation as an additional reason for stopping the exercise. It is concluded that other kinds of reaction, than bronchial obstruction such as breathing troubles not directly related to bronchial obstruction and chest pain, may be important factors that can restrict physical capacity in patients with exercise-induced respiratory symptoms
The Grothendieck Group of a Quantum Projective Space Bundle
We compute the Grothendieck group K_0 of non-commutative analogues of quantum
projective space bundles. Our results specialize to give the Grothendieck
groups of non-commutative analogues of projective spaces, and specialize to
recover the Grothendieck group of a usual projective space bundle over a
regular noetherian separated scheme. As an application we develop an
intersection theory for the quantum ruled surfaces defined by Van den Bergh.Comment: This paper is being replaced so I can correct the metadata, the
title! I (Paul) spelled Grothendieck's name incorrectly. The paper is being
reposted with the journal reference and doi added to the metadat
A transient network of telechelic polymers and microspheres : structure and rheology
We study the structure and dynamics of a transient network composed of
droplets of microemulsion connected by telechelic polymers. The polymer induces
a bridging attraction between droplets without changing their shape. A
viscoelastic behaviour is induced in the initially liquid solution,
characterised in the linear regime by a stretched exponential stress
relaxation. We analyse this relaxation in the light of classical theories of
transient networks. The role of the elastic reorganisations in the deformed
network is emphasized. In the non linear regime, a fast relaxation dynamics is
followed by a second one having the same rate as in the linear regime. This
behaviour, under step strain experiments, should induce a non monotonic
behaviour in the elastic component of the stress under constant shear rate.
However, we obtain in this case a singularity in the flow curve very different
from the one observed in other systems, that we interpret in terms of fracture
behaviour.Comment: 9 pages, 4 figure
OGLE-2005-BLG-018: Characterization of Full Physical and Orbital Parameters of a Gravitational Binary Lens
We present the analysis result of a gravitational binary-lensing event
OGLE-2005-BLG-018. The light curve of the event is characterized by 2 adjacent
strong features and a single weak feature separated from the strong features.
The light curve exhibits noticeable deviations from the best-fit model based on
standard binary parameters. To explain the deviation, we test models including
various higher-order effects of the motions of the observer, source, and lens.
From this, we find that it is necessary to account for the orbital motion of
the lens in describing the light curve. From modeling of the light curve
considering the parallax effect and Keplerian orbital motion, we are able to
measure not only the physical parameters but also a complete orbital solution
of the lens system. It is found that the event was produced by a binary lens
located in the Galactic bulge with a distance kpc from the Earth.
The individual lens components with masses and are separated with a semi-major axis of AU and
orbiting each other with a period yr. The event demonstrates
that it is possible to extract detailed information about binary lens systems
from well-resolved lensing light curves.Comment: 19 pages, 6 figure
Single-Cell Genomics Reveals a Diverse Metabolic Potential of Uncultivated Desulfatiglans-Related Deltaproteobacteria Widely Distributed in Marine Sediment
Desulfatiglans-related organisms comprise one of the most abundant deltaproteobacterial lineages in marine sediments where they occur throughout the sediment column in a gradient of increasing sulfate and organic carbon limitation with depth. Characterized Desulfatiglans isolates are dissimilatory sulfate reducers able to grow by degrading aromatic hydrocarbons. The ecophysiology of environmental Desulfatiglans-populations is poorly understood, however, possibly utilization of aromatic compounds may explain their predominance in marine subsurface sediments. We sequenced and analyzed seven Desulfatiglans-related single-cell genomes (SAGs) from Aarhus Bay sediments to characterize their metabolic potential with regard to aromatic compound degradation and energy metabolism. The average genome assembly size was 1.3 Mbp and completeness estimates ranged between 20 and 50%. Five of the SAGs (group 1) originated from the sulfate-rich surface part of the sediment while two (group 2) originated from sulfate-depleted subsurface sediment. Based on 16S rRNA gene amplicon sequencing group 2 SAGs represent the more frequent types of Deaufatig/ans-populations in Aarhus Bay sediments. Genes indicative of aromatic compound degradation could be identified in both groups, but the two groups were metabolically distinct with regard to energy conservation. Group 1 SAGs carry a full set of genes for dissimilatory sulfate reduction, whereas the group 2 SAGs lacked any genetic evidence for sulfate reduction. The latter may be due to incompleteness of the SAGs, but as alternative energy metabolisms group 2 SAGs carry the genetic potential for growth by acetogenesis and fermentation. Group 1 SAGs encoded reductive dehalogenase genes, allowing them to access organohalides and possibly conserve energy by their reduction. Both groups possess sulfatases unlike their cultured relatives allowing them to utilize sulfate esters as source of organic carbon and sulfate. In conclusion, the uncultivated marine Desulfatiglans populations are metabolically diverse, likely reflecting different strategies for coping with energy and sulfate limitation in the subsurface seabed
Subordinated masculinities : A critical inquiry into reproduction of gender norms in handovers and rounds in a forensic psychiatric care
Aims and objectives To examine how gendered discursive norms and notions of masculinity are (re)produced in professional conversations about men cared for as patients in forensic psychiatric care, with a particular focus on the centrality of language and gender. Background During verbal handovers and ward rounds, care staff converse to share information about patients and make decisions about their mental status. Spoken language is thus a pivotal tool in verbal handovers and ward rounds, one able to reproduce discourses and gender norms. Design Qualitative. Data collected from audio recordings of verbal handovers and ward rounds in a forensic psychiatric clinic were subjected to discourse analysis. The COREQ checklist was used. Results While discussing patients, staff subordinated them by reproducing a discourse typical of heteronormative, family-oriented care. The overarching discourse, which we labelledsubordinated masculinities, was supported by three other discourses:being unable to take responsibility,being drug-addictedandperforming masculinity. Such discourse was identified as a disciplining practice that subordinate's patients as a means to maintain order, rules and gender norms. Conclusion The study reveals a caring practice that position male patients as children or disabled individuals and, in that way, as subordinated other men within a context were staff reproduces a heteronormative family structured care. The process also reveals a practice were downplaying aggressive and deviant behaviour could disempower and reduce patients ' responsibility for personal actions and their possibilities to participate in their care. That finding especially seems to contradict previous findings that patients want to be able to act responsibly and, to that end, want care staff to help them. Relevance to clinical practice Nurses need to deepen their understanding of how language (re)produces discursive norms of gender and masculinity in forensic care and that process's consequences for such care.Peer reviewe
Disciplined into good conduct : Gender constructions of users in a municipal psychiatric context in Sweden
Aims and objectives To examine how gendered discursive norms and notions of masculinity and femininity were (re)produced in professional conversations about users of long‐term municipality psychiatric care. Focus is on the staff’s use of language in relation to gender constructions. Background Psychiatric care in Sweden has undergone tremendous changes in recent decades from custodian care in large hospitals to a care mainly located in a municipal context. People who need psychiatric care services often live in supporting houses. In municipal psychiatric care, staff conduct weekly professional meetings to discuss daily matters and the users’ needs. Official reports of the Swedish government have shown that staff in municipal care services treat disabled women and men differently. Studies exploring gender in relation to users of long‐term psychiatric care in municipalities have problematised the care and how staff, through language, construct users’ gender. Therefore, language used by staff is a central tool for ascribing different gender identities of users. Design The content of speech derived from audio recordings were analysed using Foucauldian discursive analysis. The COREQ checklist was used in this article. Results The results indicate that by relying on gender discourses, staff create a conditional care related to how the users should demonstrate good conduct. In line with that, an overall discourse was created: Disciplined into good conduct. It was underpinned by three discourses inherent therein: The unreliable drinker and the confession, Threatened dignity, Doing different femininities. Conclusion The community psychiatric context generates a discourse of conduct in which staff, via spoken language (re)produces gendered patterns and power imbalances as a means to manage daily work routines. Such practices of care, in which constant, nearly panoptic, control despite the intention to promote autonomy, urgently require problematising current definitions of good conduct and normality.Peer reviewe
First Stellar Velocity Dispersion Measurement of a Luminous Quasar Host with Gemini North Laser Guide Star Adaptive Optics
We present the first use of the Gemini North laser guide star adaptive optics
(LGS AO) system and an integral field unit (IFU) to measure the stellar
velocity dispersion of the host of a luminous quasar. The quasar PG1426+015
(z=0.086) was observed with the Near-Infrared Integral Field Spectrometer
(NIFS) on the 8m Gemini North telescope in the H-band as part of the Science
Verification phase of the new ALTAIR LGS AO system. The NIFS IFU and LGS AO are
well suited for host studies of luminous quasars because one can achieve a
large ratio of host to quasar light. We have measured the stellar velocity
dispersion of PG1426+015 from 0.1'' to 1'' (0.16 kpc to 1.6 kpc) to be 217+/-15
km/s based on high signal-to-noise ratio measurements of Si I, Mg I, and
several CO bandheads. This new measurement is a factor of four more precise
than a previous measurement obtained with long-slit spectroscopy and good,
natural seeing, yet was obtained with a shorter net integration time. We find
that PG1426+015 has a velocity dispersion that places it significantly above
the M-sigma relation of quiescent galaxies and lower-luminosity active galactic
nuclei with black hole masses estimated from reverberation mapping. We discuss
several possible explanations for this discrepancy that could be addressed with
similar observations of a larger sample of luminous quasars.Comment: 5 pages, 2 figures; accepted by ApJ Letter
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