1,803 research outputs found
Dimensionality of spin modulations in 1/8-doped lanthanum cuprates from the perspective of NQR and muSR experiments
We investigate the dimensionality of inhomogeneous spin modulation patterns
in the cuprate family of high-temperature superconductors with particular focus
on 1/8-doped lanthanum cuprates. We compare one-dimensional stripe modulation
pattern with two-dimensional checkerboard of spin vortices in the context of
nuclear quadrupole resonance(NQR) and muon spin rotation(muSR) experiments. In
addition, we also consider the third pattern, a two-dimensional superposition
of spin spirals. Overall, we have found that none of the above patterns leads
to a consistent interpretation of the two types of experiments considered.
This, in particular, implies that the spin vortex checkerboard cannot be ruled
out on the basis of available NQR/muSR experimental results.Comment: 6 pages, 2 figure
Variance fluctuations in nonstationary time series: a comparative study of music genres
An important problem in physics concerns the analysis of audio time series
generated by transduced acoustic phenomena. Here, we develop a new method to
quantify the scaling properties of the local variance of nonstationary time
series. We apply this technique to analyze audio signals obtained from selected
genres of music. We find quantitative differences in the correlation properties
of high art music, popular music, and dance music. We discuss the relevance of
these objective findings in relation to the subjective experience of music.Comment: 13 pages, 4 fig
Differential regulation of effector- and central-memory responses to Toxoplasma gondii infection by IL-12 revealed by tracking of Tgd057-specific CD8+ T cells
10.1371/journal.ppat.1000815PLoS Pathogens6
An Interaction between KSHV ORF57 and UIF Provides mRNA-Adaptor Redundancy in Herpesvirus Intronless mRNA Export
The hTREX complex mediates cellular bulk mRNA nuclear export by recruiting the nuclear export factor, TAP, via a direct interaction with the export adaptor, Aly. Intriguingly however, depletion of Aly only leads to a modest reduction in cellular mRNA nuclear export, suggesting the existence of additional mRNA nuclear export adaptor proteins. In order to efficiently export Kaposi's sarcoma-associated herpesvirus (KSHV) intronless mRNAs from the nucleus, the KSHV ORF57 protein recruits hTREX onto viral intronless mRNAs allowing access to the TAP-mediated export pathway. Similarly however, depletion of Aly only leads to a modest reduction in the nuclear export of KSHV intronless mRNAs. Herein, we identify a novel interaction between ORF57 and the cellular protein, UIF. We provide the first evidence that the ORF57-UIF interaction enables the recruitment of hTREX and TAP to KSHV intronless mRNAs in Aly-depleted cells. Strikingly, depletion of both Aly and UIF inhibits the formation of an ORF57-mediated nuclear export competent ribonucleoprotein particle and consequently prevents ORF57-mediated mRNA nuclear export and KSHV protein production. Importantly, these findings highlight that redundancy exists in the eukaryotic system for certain hTREX components involved in the mRNA nuclear export of intronless KSHV mRNAs
Non-linear feedback effects in coupled Boson-Fermion systems
We address ourselves to a class of systems composed of two coupled subsystems
without any intra-subsystem interaction: itinerant Fermions and localized
Bosons on a lattice. Switching on an interaction between the two subsystems
leads to feedback effects which result in a rich dynamical structure in both of
them. Such feedback features are studied on the basis of the flow equation
technique - an infinite series of infinitesimal unitary transformations - which
leads to a gradual elimination of the inter-subsystem interaction. As a result
the two subsystems get decoupled but their renormalized kinetic energies become
mutually dependent on each other. Choosing for the inter - subsystem
interaction a charge exchange term (the Boson-Fermion model) the initially
localized Bosons acquire itinerancy through their dependence on the
renormalized Fermion dispersion. This latter evolves from a free particle
dispersion into one showing a pseudogap structure near the chemical potential.
Upon lowering the temperature both subsystems simultaneously enter a
macroscopic coherent quantum state. The Bosons become superfluid, exhibiting a
soundwave like dispersion while the Fermions develop a true gap in their
dispersion. The essential physical features described by this technique are
already contained in the renormalization of the kinetic terms in the respective
Hamiltonians of the two subsystems. The extra interaction terms resulting in
the process of iteration only strengthen this physics. We compare the results
with previous calculations based on selfconsistent perturbative approaches.Comment: 14 pages, 16 figures, accepted for publication in Phys. Rev.
Nuclear Flow Excitation Function
We consider the dependence of collective flow on the nuclear surface
thickness in a Boltzmann--Uehling--Uhlenbeck transport model of heavy ion
collisions. Well defined surfaces are introduced by giving test particles a
Gaussian density profile of constant width. Zeros of the flow excitation
function are as much influenced by the surface thickness as the nuclear
equation of state, and the dependence of this effect is understood in terms of
a simple potential scattering model. Realistic calculations must also take into
account medium effects for the nucleon--nucleon cross section, and impact
parameter averaging. We find that balance energy scales with the mass number as
, where has a numerical value between 0.35 and 0.5, depending on
the assumptions about the in-medium nucleon-nucleon cross section.Comment: 11 pages (LaTeX), 7 figures (not included), MSUCL-884, WSU-NP-93-
Dietary studies in birds: testing a non-invasive method using digital photography in seabirds
This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Dietary studies give vital insights into foraging behaviour, with implications for understanding changing environmental conditions and the anthropogenic impacts on natural resources. Traditional diet sampling methods may be invasive or subject to biases, so developing non-invasive and unbiased methods applicable to a diversity of species is essential.
We used digital photography to investigate the diet fed to chicks of a prey-carrying seabird and compared our approach (photo-sampling) to a traditional method (regurgitations) for the greater crested tern Thalasseus bergii.
Over three breeding seasons, we identified >24 000 prey items of at least 48 different species, more than doubling the known diversity of prey taken by this population of terns. We present a method to estimate the length of the main prey species (anchovy Engraulis encrasicolus) from photographs, with an accuracy <1 mm and precision ~ 0·5 mm. Compared to regurgitations at two colonies, photo-sampling produced similar estimates of prey composition and size, at a faster species accumulation rate. The prey compositions collected by two researchers photo-sampling concurrently were also similar.
Photo-sampling offers a non-invasive tool to accurately and efficiently investigate the diet composition and prey size of prey-carrying birds. It reduces biases associated with observer-based studies and is simple to use. This methodology provides a novel tool to aid conservation and management decision-making in the light of the growing need to assess environmental and anthropogenic change in natural ecosystems.Department of Science and Technology, South Afric
ELM triggering conditions for the integrated modeling of H-mode plasmas
Recent advances in the integrated modeling of ELMy H-mode plasmas are
presented. A model for the H-mode pedestal and for the triggering of ELMs
predicts the height, width, and shape of the H-mode pedestal and the frequency
and width of ELMs. Formation of the pedestal and the L-H transition is the
direct result of ExB flow shear suppression of anomalous transport. The
periodic ELM crashes are triggered by either the ballooning or peeling MHD
instabilities. The BALOO, DCON, and ELITE ideal MHD stability codes are used to
derive a new parametric expression for the peeling-ballooning threshold. The
new dependence for the peeling-ballooning threshold is implemented in the ASTRA
transport code. Results of integrated modeling of DIII-D like discharges are
presented and compared with experimental observations. The results from the
ideal MHD stability codes are compared with results from the resistive MHD
stability code NIMROD.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004,
Nice (France
Comparable rates of secondary surgery between anterior cruciate ligament repair with suture tape augmentation and anterior cruciate ligament reconstruction
Purpose
The aim of this study was to determine the frequency of secondary surgery following anterior cruciate ligament (ACL) repair with suture tape augmentation in comparison to conventional hamstring ACL reconstruction. We hypothesised that there would be no differences between the groups.
Methods
This was a retrospective comparison study of patients undergoing ACL surgery between September 2011 and April 2018. Two hundred and 73 patients underwent ACL reconstruction using hamstring autograft. During the same timeframe, 137 patients with an acute proximal ACL rupture underwent ACL repair with suture tape augmentation. One patient was lost to follow-up in the ACL reconstruction group leaving 272 patients (99.6%) for the final analysis. In the ACL repair group, three patients were lost to follow-up leaving 134 patents (97.8%) for the final analysis. Secondary surgery was identified by contacting the patients by email/telephone and reviewing patient notes at the time of this analysis.
Results
Re-rupture occurred in 32 patients (11.8%) in the ACL reconstruction group compared to 22 patients (16.4%) in the ACL repair group (p = 0.194). Contralateral ACL rupture occurred in four patients (1.5%) in the ACL reconstruction group compared to three patients (2.2%) in the ACL repair group (p = 0.224). In the ACL reconstruction group, nine patients (3.3%) required secondary meniscal surgery whilst five patients (3.7%) required meniscal surgery in the ACL repair group (p = 0.830). Seven other operations were performed in the ACL reconstruction group (2.6%) compared to three other operations in the ACL repair group (2.2%) (p = 0.374). The overall number of patients undergoing secondary surgery in the ACL reconstruction group was 52 (19.1%) in comparison to 30 (22.4%) in the ACL repair group (p = 0.114).
Conclusion
ACL repair with suture tape augmentation for acute proximal ruptures demonstrated comparable rates of secondary surgery with hamstring ACL reconstruction
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