590 research outputs found
Normal mode splitting and mechanical effects of an optical lattice in a ring cavity
A novel regime of atom-cavity physics is explored, arising when large atom
samples dispersively interact with high-finesse optical cavities. A stable far
detuned optical lattice of several million rubidium atoms is formed inside an
optical ring resonator by coupling equal amounts of laser light to each
propagation direction of a longitudinal cavity mode. An adjacent longitudinal
mode, detunedby about 3 GHz, is used to perform probe transmission spectroscopy
of the system. The atom-cavity coupling for the lattice beams and the probe is
dispersive and dissipation results only from the finite photon-storage time.
The observation of two well-resolved normal modes demonstrates the regime of
strong cooperative coupling. The details of the normal mode spectrum reveal
mechanical effects associated with the retroaction of the probe upon the
optical lattice.Comment: 4 pages, 3 figure
Some genus 3 curves with many points
Using an explicit family of plane quartic curves, we prove the existence of a
genus 3 curve over any finite field of characteristic 3 whose number of
rational points stays within a fixed distance from the Hasse-Weil-Serre upper
bound. We also provide an intrinsic characterization of so-called Legendre
elliptic curves
Moments of the critical values of families of elliptic curves, with applications
We make conjectures on the moments of the central values of the family of all
elliptic curves and on the moments of the first derivative of the central
values of a large family of positive rank curves. In both cases the order of
magnitude is the same as that of the moments of the central values of an
orthogonal family of L-functions. Notably, we predict that the critical values
of all rank 1 elliptic curves is logarithmically larger than the rank 1 curves
in the positive rank family.
Furthermore, as arithmetical applications we make a conjecture on the
distribution of a_p's amongst all rank 2 elliptic curves, and also show how the
Riemann hypothesis can be deduced from sufficient knowledge of the first moment
of the positive rank family (based on an idea of Iwaniec).Comment: 24 page
The use of self-report measures to examine changes in perception in response to fittings using different signal processing parameters
Clinicians have long used self-report methods to assess hearing aid benefit. However, there are fewer data as to whether self-report instruments can be used to compare differences between signal processing settings. This study examined how self-perceived performance varied as a function of modifications in signal processing using two self-report measures. Data were collected as part of a double-blind randomised crossover clinical trial. Participants were fit with two fittings: mild processing (slow time constants, disabled frequency lowering) and strong processing (fast time constants, frequency lowering enabled). The speech, spatial, and qualities of hearing (SSQ) questionnaire and the Effectiveness of Auditory Rehabilitation (EAR) questionnaire were collected at multiple time points. Older adults with sensorineural hearing loss who had not used hearing aids within the previous year participated (49 older adults were consented; 40 were included in the final data analyses). Findings show that listeners report a difference in perceived performance when hearing aid features are modified. Both self-report measures were able to capture this change in perceived performance. Self-report measures provide a tool for capturing changes in perceived performance when hearing aid processing features are modified and may enhance provision of an evidence-based hearing aid fitting
The non-steady-state growth of divergent pearlite in Fe–C–Mn steels: a phase-field investigation
Cubic Curves, Finite Geometry and Cryptography
Some geometry on non-singular cubic curves, mainly over finite fields, is
surveyed. Such a curve has 9,3,1 or 0 points of inflexion, and cubic curves are
classified accordingly. The group structure and the possible numbers of
rational points are also surveyed. A possible strengthening of the security of
elliptic curve cryptography is proposed using a `shared secret' related to the
group law. Cubic curves are also used in a new way to construct sets of points
having various combinatorial and geometric properties that are of particular
interest in finite Desarguesian planes.Comment: This is a version of our article to appear in Acta Applicandae
Mathematicae. In this version, we have corrected a sentence in the third
paragraph. The final publication is available at springerlink.com at
http://www.springerlink.com/content/xh85647871215644
Healthcare Resource Utilization Among Patients in England with Systemic Sclerosis-Associated Interstitial Lung Disease: A Retrospective Database Analysis
Introduction
Systemic sclerosis-associated interstitial lung disease (SSc-ILD) places a substantial burden on patients and healthcare systems. The objectives of this study were to describe clinical characteristics and assess healthcare resource utilization and costs of patients with SSc-ILD in England, compared with patients with non-pulmonary organ involvement related to SSc (SSc-OOI).
Methods
This population-based retrospective study used data from the Clinical Practice Research Datalink linked to Hospital Episode Statistics. Data were extracted from medical records dated January 1, 2005 to March 31, 2016. Patients with SSc were identified and placed in subgroups based on organ involvement: SSc-ILD, SSc-OOI, and both (SSc-ILD-OOI). Patients with SSc-ILD-OOI were included in both the SSc-ILD and SSc-OOI subgroups. All-cause healthcare costs, excluding medication costs, were calculated to 2016 British pounds sterling (£).
Results
This study included 675 patients with SSc: 174 (26%) had neither ILD nor other organ involvement (OOI); 127 (19%) had SSc-ILD; 477 (71%) had SSc-OOI; 103 (15%) had SSc-ILD-OOI. Age-weighted median [interquartile range (IQR)] annual healthcare costs per patient were: £1496 (£664–£2817) in SSc only; £6375 (£3451–£15,041) in SSc-ILD; £4084 (£1454–£10,105) in SSc-OOI; £6632 (£4023–£17,009) in SSc-ILD-OOI. In multivariate analysis, older age at diagnosis, diagnosis of anemia, and number of comorbid diseases were associated with higher yearly healthcare costs.
Conclusion
The annual healthcare cost for patients with SSc-ILD is substantial, and higher than that of patients with SSc-OOI or SSc only. These results quantify the economic burden of SSc-ILD in a real-world setting, and highlight the need for treatment of this disease
Multiple feedback loops through cytokinin signaling control stem cell number within the Arabidopsis shoot meristem
A central unanswered question in stem cell biology, both in plants and in animals, is how the spatial organization of stem cell niches are maintained as cells move through them. We address this question for the shoot apical meristem (SAM) which harbors pluripotent stem cells responsible for growth of above-ground tissues in flowering plants. We find that localized perception of the plant hormone cytokinin establishes a spatial domain in which cell fate is respecified through induction of the master regulator WUSCHEL as cells are displaced during growth. Cytokinin-induced WUSCHEL expression occurs through both CLAVATA-dependent and CLAVATA-independent pathways. Computational analysis shows that feedback between cytokinin response and genetic regulators predicts their relative patterning, which we confirm experimentally. Our results also may explain how increasing cytokinin concentration leads to the first steps in reestablishing the shoot stem cell niche in vitro
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