Publications by authors named "Tobey R"

Unlabelled: Policy Points As essential access points to primary care for almost 29 million US patients, of whom 47% are Medicaid enrollees, health centers are positioned to implement the population health management necessary in value-based payment (VBP) contracts. Primary care payment reform requires multiple payment methodologies used together to provide flexibility to care providers, encourage investments in infrastructure and new services, and offer incentives for achieving better health outcomes. State policy and significant financial incentives from Medicaid agencies and Medicaid managed care plans will likely be required to increase health center participation in VBP, which is consistent with broader state efforts to expand investment in primary care.

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Objectives: To understand factors associated with federally qualified health center (FQHC) financial performance.

Study Design: We used multivariate linear regression to identify correlates of health center financial performance. We examined six measures of health center financial performance across four domains: margin (operating margin), liquidity (days cash on hand [DCOH], current ratio), solvency (debt-to-equity ratio), and others (net patient accounts receivable days, personnel-related expenses).

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We investigate polarization-dependent ultrafast photocurrents in the Weyl semimetal TaAs using terahertz (THz) emission spectroscopy. Our results reveal that highly directional, transient photocurrents are generated along the noncentrosymmetric c axis regardless of incident light polarization, while helicity-dependent photocurrents are excited within the ab plane. This is consistent with earlier static photocurrent experiments, and demonstrates on the basis of both the physical constraints imposed by symmetry and the temporal dynamics intrinsic to current generation and decay that optically induced photocurrents in TaAs are inherent to the underlying crystal symmetry of the transition metal monopnictide family of Weyl semimetals.

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Objectives With the widespread use of DNA testing, police, death investigators, and attorneys need to be aware of the capabilities of this technology. This review provides an overview of scenarios where DNA evidence has played a major role in homicide investigations in order to highlight important educational issues for police, death investigators, forensic pathologists, and attorneys. Methods This was a nonrandom, observational, retrospective study.

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Objectives: This study assessed the effect of 2 types of hydroxyethyl starches (HES) on renal integrity and blood transfusion in cardiac surgery patients.

Design: Retrospective investigation.

Setting: Patients from a single tertiary medical center.

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Recent efforts in medical settings to identify social determinants of health have focused primarily on screening for the purpose of improving care for individual patients and getting standardized data into electronic health records (EHRs). Relatively little attention has been given to processes needed to extract data on social determinants of health out of medical records with adequate validity and efficiency to facilitate analysis across individual encounters to inform population health efforts relevant to the health care sector. In this article we describe the rationale for extracting data on social determinants of health from EHRs, including the potential influence of aggregated data on quality improvement activities and health care payment reform.

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Free-standing thin films of magnetic ion intercalated transition metal dichalcogenides are produced using ultramicrotoming techniques. Films of thicknesses ranging from 30 nm to 250 nm were achieved and characterized using transmission electron diffraction and x-ray magnetic circular dichroism. Diffraction measurements visualize the long range crystallographic ordering of the intercalated ions, while the dichroism measurements directly assess the orbital contributions to the total magnetic moment.

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Surface magnetoelastic waves are coupled elastic and magnetic excitations that propagate along the surface of a magnetic material. Ultrafast optical techniques allow for a non-contact excitation and detection scheme while providing the ability to measure both elastic and magnetic components individually. Here we describe a simple setup suitable for excitation and time resolved measurements of high frequency magnetoelastic waves, which is based on the transient grating technique.

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We measure magnetization and structural dynamics in two intercalant-ordered transition metal dichalcogenides: Fe0.25TaS2 and Mn0.25TaS2.

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We report femtosecond resonant soft x-ray diffraction measurements of the dynamics of the charge order and of the crystal lattice in nonsuperconducting, stripe-ordered La1.875Ba0.125CuO4.

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Optical pulses at THz and mid-infrared frequencies tuned to specific vibrational resonances modulate the lattice along chosen normal mode coordinates. In this way, solids can be switched between competing electronic phases and new states are created. Here, we use vibrational modulation to make electronic interactions (Hubbard-U) in Mott-insulator time dependent.

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Time resolved optical spectroscopy is used to elucidate the dynamics of photodoped spin-aligned carriers in the presence of an underlying magnetic lattice in the multiferroic compound TbMnO(3). The transient responses while probing d-d intersite transitions show marked differences along different crystallographic directions, which are discussed in terms of the interplay between the processes of hopping of the photo-injected electrons and the magnetic order in the material.

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We used ultrafast resonant soft x-ray diffraction to probe the picosecond dynamics of spin and orbital order in La(0.5)Sr(1.5)MnO(4) after photoexcitation with a femtosecond pulse of 1.

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One of the most intriguing features of some high-temperature cuprate superconductors is the interplay between one-dimensional "striped" spin order and charge order, and superconductivity. We used mid-infrared femtosecond pulses to transform one such stripe-ordered compound, nonsuperconducting La(1.675)Eu(0.

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The transient optical conductivity of photoexcited 1T-TaS2 is determined over a three-order-of-magnitude frequency range. Prompt collapse and recovery of the Mott gap is observed. However, we find important differences between this transient metallic state and that seen across the thermally driven insulator-metal transition.

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An ultrafast electronic phase transition, associated with melting of orbital order, is driven in La1/2Sr3/2MnO4 by selectively exciting the Mn-O stretching mode with femtosecond pulses at 16 microm wavelength. The energy coupled into this vibration is less than 1% of that necessary to induce the transition thermally. Nonthermal melting of this electronic phase originates from coherent lattice displacements comparable to the static Jahn-Teller distortion.

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We present the first experimental demonstration of lensless diffractive imaging using coherent soft x rays generated by a tabletop soft-x-ray source. A 29 nm high harmonic beam illuminates an object, and the subsequent diffraction is collected on an x-ray CCD camera. High dynamic range diffraction patterns are obtained by taking multiple exposures while blocking small-angle diffraction using beam blocks of varying size.

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Controlling a phase of matter by coherently manipulating specific vibrational modes has long been an attractive (yet elusive) goal for ultrafast science. Solids with strongly correlated electrons, in which even subtle crystallographic distortions can result in colossal changes of the electronic and magnetic properties, could be directed between competing phases by such selective vibrational excitation. In this way, the dynamics of the electronic ground state of the system become accessible, and new insight into the underlying physics might be gained.

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We demonstrate femtosecond time-resolved dynamic Gabor holography using highly coherent extreme ultraviolet light generated by high harmonic upconversion of a femtosecond laser. By reflecting this light from an impulsively heated surface, we implement a simple and robust single-reflection geometry for phase-sensitive holographic detection at extreme UV wavelengths. Using this setup, we study the ultrafast deformation and subsequent acoustic oscillations within a thin metal film.

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To determine whether the basal forebrain-hippocampal cholinergic system supports sexually dimorphic functionality, male and female Long-Evans rats were given either selective medial septum/vertical limb of the diagonal band (MS/VDB) cholinergic lesions using the neurotoxin 192 IgG-saporin or a control surgery and then postoperatively tested in a set of standard spatial learning tasks in the Morris water maze. Lesions were highly specific and effective as confirmed by both choline acetyltransferase/parvalbumin immunostaining and acetylcholinesterase histochemistry. Female controls performed worse than male controls in place learning and MS/VDB lesions failed to impair spatial learning in male rats, both consistent with previous findings.

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Although experimental trials often identify optimal strategies for improving community health, transferring operational innovation from well-funded research programs to resource-constrained settings often languishes. Because research initiatives are based in institutions equipped with unique resources and staff capabilities, results are often dismissed by decisionmakers as irrelevant to large-scale operations and national health policy. This article describes an initiative undertaken in Nkwanta District, Ghana, focusing on this problem.

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We demonstrate a general procedure for varying the repetition rate of a modelocked Ti:sapphire laser using an asymmetric focusing geometry. Using this procedure, we have made an extended length cavity with a repetition rate of 45 MHz, and a reduced length cavity with a repetition rate of 275 MHz, each of which generates sub-20 fs pulses. This procedure allows the repetition rate of the laser to be more precisely tailored for a variety of applications without compromise in performance.

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We demonstrate the generation of very high-order harmonics, up to 250 eV, using argon gas. This extends by 100 eV the highest harmonics previously observed using Ar and exceeds the energies observed using any other medium besides helium. This advance is made possible by using a waveguide geometry to limit plasma-induced laser beam defocusing, making it possible to generate high harmonics from Ar ions.

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