Publications

Accountable care organizations (ACOs) are often discussed and promoted as driven by physicians, hospitals, and other health care providers. However, because of the flexible nature of ACO contracts, management organizations may also become partners in ACOs. We used data from 2013-15 on 276 ACOs from the National Survey of Accountable Care Organizations to understand the prevalence of nonprovider management partners' involvement in ACOs, the services these partners provide, and the structure of ACOs that have such partners. We found that 37 percent of ACOs reported having a management partner, and two-thirds of these ACOs reported that the partner shared in the financial risks or rewards. Among ACOs with partners, 94 percent had data services provided by the partner, 87 percent received administrative services, 68 percent received educational services, and 66 percent received care coordination services. Half received all four of these services from their partner. ACOs with partners were more heavily primary care than other ACOs. ACOs with and without partners had similar performance on costs and quality in Medicare ACO programs. Our findings suggest that management partners play a central role in many ACOs, perhaps supplying smaller and physician-run ACOs with services or expertise perceived as necessary for ACO success.

The intermediate band solar cell (IBSC) is an attractive concept to achieve photovoltaic conversion efficiencies exceeding the Shockley-Quiessar efficiency limit for a single junction cell. In an IBSC, a partially occupied energy band located within the bandgap region of a semiconductor serves as a ‘stepping stone’ for the absorption of lower energy photons that are nominally not absorbed by the cell. In theory, the addition of this ‘intermediate band’ would provide a high photocurrent while maintaining a high output voltage. 1 Recently, an IBSC device using the highly-mismatched semiconductor GaNAs alloy (HMA’s) has demonstrated optical activity from the three energy bands and is a proof of principle for the IBSC concept.[2] It has been proposed that the GaAsPN dilute nitride alloy system is another promising candidate material for IBSC’s. 3 Calculations based on the band anticrossing model 4 show that the intermediate band formed by the localized N level in GaN x As y P 1-x-y alloys with y<0.7 will be narrow and completely separated from the conduction band and hence more suitable as an intermediate band semiconductor for IBSC’s. 3 The location of the IB (E - ) and the conduction band (E + ) of this material system can be tuned more effectively for optimal absorption of the solar spectrum by changing the As/P ratio ( y ).. Furthermore, GaAs y P 1-y exhibits a direct-indirect gap crossover at approximately y =0.5, and for alloys with compositions y>0.5 the photon absorption occurs at the lower energy Γ band, yet electron transport may take place in the indirect X band. This could result in an IBSC absorber material with a high absorption coefficient that retains long carrier lifetimes. 5 This work presents the design and characterization of a GaAsPN-based IBSC device. In order to fabricate a functioning IBSC device, first p-type, and n-type GaNAsP were grown and characterized in terms of their optical and electrical properties. We found that efficient p and n-type doping of GaNAsP can be achieved with Be and Si, respectively. Next, GaAsPN-based IBSC devices were grown by gas-source molecular beam epitaxy (MBE) on GaP substrate with a thick (~1.5µm) compositionally graded GaAsP buffer layers. Both a blocked intermediate band structure, where the intermediate band is electrically isolated from the valence and conduction bands, and an unblocked intermediate band structure (as a reference structure) were considered. The design of the structure was optimized to achieve efficient charge-carrier extraction, yet still demonstrate absorption from the three possible band-to-band transitions.The external quantum efficiency, both with and without a white-light bias, was used to evaluate the spectral response of the devices and the optical activity of the intermediate band. I-V measurements using both AM 1.5 and under 30x concentration were used to evaluate the PV device performance. [1] Luque, A., Marti, A. & Stanley, C. Understanding intermediate-band solar cells. Nature Photonics 6 , 146–152 (2012). [2] López, N., Reichertz, L., Yu, K.M., Campman, K. & Walukiewicz, W. Engineering the Electronic Band Structure for Multiband Solar Cells. Phys. Rev. Lett. 106 , 028701 (2011). [4] Shan, W. et al. Band anticrossing in GaInNAs alloys. Phys. Rev. Lett. 82 , 1221–1224 (1999). [5] Yu, K. M. et al. Multiband GaNAsP quaternary alloys. Appl. Phys. Lett 88 , 092110 (2006). [6] Y. J. Kuang, et al. GaNAsP: An intermediate band semiconductor grown by gas-source molecular beam epitaxy, Appl. Phys. Lett. 102 , - (2013).

ABSTRACT Dopaminergic neurons innervate extensive areas of the brain and release dopamine (DA) onto a wide range of target neurons. However, DA release is also precisely regulated, and in Drosophila, DA is released specifically onto mushroom body (MB) neurons, which have been coincidentally activated by cholinergic and glutamatergic inputs. The mechanism for this precise release has been unclear. Here we found that coincidentally activated MB neurons generate carbon monoxide (CO) which functions as a retrograde signal evoking local DA release from presynaptic terminals. CO production depends on activity of heme oxygenase in post-synaptic MB neurons, and CO-evoked DA release requires Ca 2+ efflux through ryanodine receptors in DA terminals. CO is only produced in MB areas receiving coincident activation, and removal of CO using scavengers blocks DA release. We propose that DA neurons utilize two distinct modes of transmission to produce global and local DA signaling. SIGNIFICANCE STATEMENT Dopamine (DA) is needed for various higher brain functions including memory formation. However, DA neurons form extensive synaptic connections, while memory formation requires highly specific and localized DA release. Here we identify a mechanism through which DA release from presynaptic terminals is controlled by postsynaptic activity. Postsynaptic neurons activated by cholinergic and glutamatergic inputs generate carbon monoxide, which acts as a retrograde messenger inducing presynaptic DA release. Released DA is required for memory-associated plasticity. Our work identifies a novel mechanism that restricts DA release to the specific postsynaptic sites that require DA during memory formation.

BackgroundDatabases of practicing physicians are important for studies that require sampling physicians or counting the physician population in a given area. However, little is known about how the three main sampling frames differ from each other.ObjectiveOur purpose was to compare the National Provider and Plan Enumeration System (NPPES), the American Medical Association Masterfile and the SK&A physician file.MethodsWe randomly sampled 3000 physicians from the NPPES (500 in six specialties). We conducted two- and three-way comparisons across three databases to determine the extent to which they matched on address and specialty. In addition, we randomly selected 1200 physicians (200 per specialty) for telephone verification.Key resultsOne thousand, six hundred and fifty-five physicians (55 %) were found in all three data files. The SK&A data file had the highest rate of missing physicians when compared to the NPPES, and varied by specialty (50 % in radiology vs. 28 % in cardiology). NPPES and SK&A had the highest rates of matching mailing address information, while the AMA Masterfile had low rates compared with the NPPES. We were able to confirm 65 % of physicians' address information by phone. The NPPES and SK&A had similar rates of correct address information in phone verification (72-94 % and 79-92 %, respectively, across specialties), while the AMA Masterfile had significantly lower rates of correct address information across all specialties (32-54 % across specialties).ConclusionsNone of the data files in this study were perfect; the fact that we were unable to reach one-third of our telephone verification sample is troubling. However, the study offers some encouragement for researchers conducting physician surveys. The NPPES and to a lesser extent, the SK&A file, appear to provide reasonably accurate, up-to-date address information for physicians billing public and provider insurers.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

Abstract T cells express clonally distributed alpha beta or gamma delta Ag receptor heterodimers. Transcriptional enhancers for the genes of all four subunits are active in both gamma delta and alpha beta T cells, but are less active or inactive in other cells. Conserved sequence motifs are present in all four enhancers, suggesting that common transcription factors regulate TCR gene expression. One of these motifs in the gamma 3 site of the TCR-gamma enhancer is similar to motifs found in several other lymphoid-specific and viral enhancers. This conserved "core" sequence is present in the enhancers of Moloney and SL3-3 murine leukemia viruses, important for transcription in T cells and in determining disease specificity. Here we characterize the gamma 3 site of the gamma enhancer and a corresponding homologous site, delta E3, of the TCR-delta enhancer. Our results suggest that the core site is critical for activity of the 200-bp gamma enhancer fragment and of the gamma 3 and delta E3 sites. Furthermore, we identify a nuclear factor in human T cell lines that specifically binds the core region in these and several other core-containing enhancers. This factor may be identical to or related to a purified bovine nuclear core binding factor that binds the core region of the Moloney murine leukemia virus enhancer, gamma 3 and delta E3 sites, suggesting that similar proteins regulate the TCR-gamma, delta and Moloney murine leukemia virus enhancers. Other sequences in the gamma 3 site upstream of the core sequence are also critical for activity in T cells, suggesting that at least two different factors are required for functional activity of the gamma 3 site.

We study the notion of consistency between a 3D shape and a 2D observation\nand propose a differentiable formulation which allows computing gradients of\nthe 3D shape given an observation from an arbitrary view. We do so by\nreformulating view consistency using a differentiable ray consistency (DRC)\nterm. We show that this formulation can be incorporated in a learning framework\nto leverage different types of multi-view observations e.g. foreground masks,\ndepth, color images, semantics etc. as supervision for learning single-view 3D\nprediction. We present empirical analysis of our technique in a controlled\nsetting. We also show that this approach allows us to improve over existing\ntechniques for single-view reconstruction of objects from the PASCAL VOC\ndataset.\n

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