Feshbach molecule formation in a Bose-Fermi mixture

We investigate magnetoassociation of ultracold fermionic Feshbach molecules in a mixture of $^{40}$K and $^{87}$Rb atoms, where we can create as many as $7\times 10^4$ $^{40}$K$^{87}$Rb molecules with a conversion efficiency as high as 45%. In the perturbative regime, we find that the conversion efficiency depends linearly on the density overlap of the two gases, with a slope that matches a parameter-free model that uses only the atom masses and the known Feshbach resonance parameters. In the saturated regime, we find that the maximum number of Feshbach molecules depends on the atoms' phase-space density. At higher temperatures, our measurements agree with a phenomenological model that successfully describes the formation of bosonic molecules from either Bose or Fermi gases. However, for quantum degenerate atom gas mixtures, we measure significantly fewer molecules than this model predicts.Comment: 6 pages, 6 figure

redstarts (Setophaga ruticilla)

Breeding dispersions and site fidelity of America

Physiotherapy practice in the private sector: organizational characteristics and models.

BACKGROUND: Even if a large proportion of physiotherapists work in the private sector worldwide, very little is known of the organizations within which they practice. Such knowledge is important to help understand contexts of practice and how they influence the quality of services and patient outcomes. The purpose of this study was to: 1) describe characteristics of organizations where physiotherapists practice in the private sector, and 2) explore the existence of a taxonomy of organizational models. METHODS: This was a cross-sectional quantitative survey of 236 randomly-selected physiotherapists. Participants completed a purpose-designed questionnaire online or by telephone, covering organizational vision, resources, structures and practices. Organizational characteristics were analyzed descriptively, while organizational models were identified by multiple correspondence analyses. RESULTS: Most organizations were for-profit (93.2%), located in urban areas (91.5%), and within buildings containing multiple businesses/organizations (76.7%). The majority included multiple providers (89.8%) from diverse professions, mainly physiotherapy assistants (68.7%), massage therapists (67.3%) and osteopaths (50.2%). Four organizational models were identified: 1) solo practice, 2) middle-scale multiprovider, 3) large-scale multiprovider and 4) mixed. CONCLUSIONS: The results of this study provide a detailed description of the organizations where physiotherapists practice, and highlight the importance of human resources in differentiating organizational models. Further research examining the influences of these organizational characteristics and models on outcomes such as physiotherapists' professional practices and patient outcomes are needed

Coronal mass ejections, magnetic clouds, and relativistic magnetospheric electron events: ISTP

The role of high-speed solar wind streams in driving relativistic electron acceleration within the Earth\u27s magnetosphere during solar activity minimum conditions has been well documented. The rising phase of the new solar activity cycle (cycle 23) commenced in 1996, and there have recently been a number of coronal mass ejections (CMEs) and related “magnetic clouds” at 1 AU. As these CME/cloud systems interact with the Earth\u27s magnetosphere, some events produce substantial enhancements in the magnetospheric energetic particle population while others do not. This paper compares and contrasts relativistic electron signatures observed by the POLAR, SAMPEX, Highly Elliptical Orbit, and geostationary orbit spacecraft during two magnetic cloud events: May 27–29, 1996, and January 10–11, 1997. Sequences were observed in each case in which the interplanetary magnetic field was first strongly southward and then rotated northward. In both cases, there were large solar wind density enhancements toward the end of the cloud passage at 1 AU. Strong energetic electron acceleration was observed in the January event, but not in the May event. The relative geoeffectiveness for these two cases is assessed, and it is concluded that large induced electric fields (∂B/∂t) caused in situ acceleration of electrons throughout the outer radiation zone during the January 1997 event

Magnetic Ordering in the High-Pressure Phases of Rare Earth Elements Holmium and Dysprosium Revealed by Neutron Diffraction

Neutron diffraction experiments on rare earth metals dysprosium (Dy) and holmium (Ho) have been performed to high pressure and low temperature using novel large-volume diamond anvil cells (DAC) at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). Neutron diffraction is necessary to determine the magnetic structure of these materials due to the intrinsic spin property of neutrons. High pressure neutron diffraction experiments have historically been limited in the pressure and temperature range achievable due to the use of Paris-Edinburgh (PE) press, however new advances in large volume diamond anvil cells allows a much broader range of pressures and temperatures than before. Neutron diffraction data have been taken at two different wavelengths in order to observe peaks in a wide-range of momentum transfer of 0.63 Å-1 to 13.5 Å-1 (interplanar d-spacings in the range of 10 Å to 0.5 Å), arising from the nuclear lattice long-range magnetic ordering. These techniques, when combined and with the addition of high-pressure x-ray diffraction data have revealed the crystal phases of Dy, Ho, and erbium (Er) to pressures up to 280 GPa as well as the magnetic structures present in the crystalline phases of Dy and Ho at low temperatures down to 10 Kelvin and from ambient pressure to 22 GPa and 31 GPa, respectively. The high-pressure structural data have confirmed the existence of an orthorhombic phase with 16 atoms (oF16) in heavy rare earth metals reinforcing their similarity with the structural trends in actinide iii metals. The magnetic structural refinements have yielded complex magnetic structures in ambient and high-pressure phases of heavy lanthanides with magnetic propagation vectors that are commensurate as well as incommensurate with the lattice derived from x-ray structural investigations. The incommensurate and commensurate propagation vectors as a function of pressure and temperature in heavy lanthanides will provide a critical test for validation of future first principles calculations on magnetic ordering in these materials

Joint localization of pursuit quadcopters and target using monocular cues

Pursuit robots (autonomous robots tasked with tracking and pursuing a moving target) require accurate tracking of the target's position over time. One possibly effective pursuit platform is a quadcopter equipped with basic sensors and a monocular camera. However, combined noise of the quadcopter's sensors causes large disturbances of target's 3D position estimate. To solve this problem, in this paper, we propose a novel method for joint localization of a quadcopter pursuer with a monocular camera and an arbitrary target. Our method localizes both the pursuer and target with respect to a common reference frame. The joint localization method fuses the quadcopter's kinematics and the target's dynamics in a joint state space model. We show that predicting and correcting pursuer and target trajectories simultaneously produces better results than standard approaches to estimating relative target trajectories in a 3D coordinate system. Our method also comprises a computationally efficient visual tracking method capable of redetecting a temporarily lost target. The efficiency of the proposed method is demonstrated by a series of experiments with a real quadcopter pursuing a human. The results show that the visual tracker can deal effectively with target occlusions and that joint localization outperforms standard localization methods

Exploring residual risk for diabetes and microvascular disease in the Diabetes Prevention Program Outcomes Study (DPPOS)

Aim Approximately half of the participants in the Diabetes Prevention Outcomes Study (DPPOS) had diabetes after 15 years of follow-up, whereas nearly all the others remained with pre-diabetes. We examined whether formerly unexplored factors in the DPPOS coexisted with known risk factors that posed additional risk for, or protection from, diabetes as well as microvascular disease. Methods Cox proportional hazard models were used to examine predictors of diabetes. Sequential modelling procedures considered known and formerly unexplored factors. We also constructed models to determine whether the same unexplored factors that associated with progression to diabetes also predicted the prevalence of microvascular disease. Hazard ratios (HR) are per standard deviation change in the variable. Results In models adjusted for demographics and known diabetes risk factors, two formerly unknown factors were associated with risk for both diabetes and microvascular disease: number of medications taken (HR = 1.07, 95% confidence intervals (95% CI) 1.03 to 1.12 for diabetes; odds ratio (OR) = 1.10, 95% CI 1.04 to 1.16 for microvascular disease) and variability in HbA1c (HR = 1.02, 95% CI 1.01 to 1.03 for diabetes; OR = 1.06, 95% CI 1.04 to 1.09 for microvascular disease per sd). Total comorbidities increased risk for diabetes (HR = 1.10, 95% CI 1.04 to 1.16), whereas higher systolic (OR = 1.22, 95% CI 1.13 to 1.31) and diastolic (OR = 1.14, 95% CI 1.05 to 1.22) blood pressure, as well as the use of anti-hypertensives (OR = 1.41, 95% CI 1.23 to 1.62), increased risk of microvascular disease. Conclusions Several formerly unexplored factors in the DPPOS predicted additional risk for diabetes and/or microvascular disease – particularly hypertension and the use of anti-hypertensive medications – helping to explain some of the residual disease risk in participants of the DPPOS

Scaling of solar wind e and the AU, AL and AE indices as seen by WIND

We apply the finite size scaling technique to quantify the statistical properties of fluctuations in AU, AL and AE indices and in the parameter that represents energy input from the solar wind into the magnetosphere. We find that the exponents needed to rescale the probability density functions (PDF) of the fluctuations are the same to within experimental error for all four quantities. This self-similarity persists for time scales up to ~4 hours for AU, AL and and up to ~2 hours for AE. Fluctuations on shorter time scales than these are found to have similar long-tailed (leptokurtic) PDF, consistent with an underlying turbulent process. These quantitative and model-independent results place important constraints on models for the coupled solar wind-magnetosphere system

Is Sophistication Always Better? Can Perceived Data Analytic Tool Sophistication Lead to Biased Judgements?

The rise of technology-enabled data analytic tools creates opportunities for firms to improve audit quality related to complex estimates. To combat auditors’ resistance to using technology-enabled tools, firms may promote the sophistication of such tools to their audit staff. However, there is a paucity of research that has examined how auditors’ perceived sophistication of an analytic tool impacts judgments about audit evidence. We conduct an experiment and find that, holding all other information constant, the preferences of an audit supervisor interact with the perceived sophistication of an analytic tool to jointly impact auditors’ anticipated evaluation from a supervisor and, in turn, their evidence assessment decisions when auditing a complex estimate. As such, the promotion of tool sophistication by audit firms can significantly affect the audit of complex estimates to a greater degree than what would be expected. Implications for audit theory and practice are discussed