1,348 research outputs found

    Development of a Dynamic Investment Strategy under Alternative Inflation Cycle Scenarios

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    Inflation and inflation cycles have been a major underlying reason for the financial successes and failures of real estate investors in recent history. These cycles have complex impacts on cash flow variables and thus on real estate returns and investment values. This study presents a decision framework and operational model to project investment returns for alternative inflation cycle scenarios and demonstrates their application for developing a dynamic real estate investment strategy. Such a strategy provides for portfolio revisions during different stages of the inflation cycle and assumes that investors seek to maximize expected "real" rates of return and hence owner's wealth. A probabilistic discounted cash flow model is designed and used to inflation-adjust each cash flow variable affected. Mathematical relationships are developed for specifying unique cash flow variable linkages and sensitivities, with lead and lag periods consistent with empirical evidence of timing of inflation impacts. Finally strategic implications for acquisition and disposition policy are discussed.

    TCT-100 Real-World Experience and Outcomes of Protected Versus Unprotected Left Main Percutaneous Coronary Intervention: Insights From the VA CART Program

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    Background: Outcomes of protected left main (PLM) and unprotected left main (ULM) percutaneous coronary intervention (PCI) are not well defined in contemporary U.S. practice. Previous studies of real-world data have shown worse in-hospital outcomes of ULM PCI compared with randomized trial data. We used a large national registry to characterize real-world practice and outcomes of left main PCI. Methods: Data were collected from the Veteran Affairs (VA) Clinical Assessment Reporting and Tracking (CART) Program for patients undergoing left main PCI between 2009 and 2019. PLM PCI was defined by the presence of at least 1 functioning bypass graft, and ULM PCI was defined as patients with no bypass grafting. Temporal trends, patient and procedure characteristics, anatomic complexity, and clinical complexity were assessed. A 1-to-1 propensity-matched analysis was performed using common comorbidities and clinical variables. One-year outcome analyses were conducted for major adverse cardiovascular events (MACE), all-cause mortality, rehospitalization for myocardial infarction (MI) and revascularization. Results: Of 4,351 patients undergoing left main PCI, 2,800 were PLM PCI and 1,551 were ULM PCI, of which 1,335 PLM and ULM PCI were included in the propensity matched cohort. Patients undergoing ULM PCI were older, more likely to present with acute coronary syndrome (ACS) and had a higher clinical complexity. In the propensity-matched cohort, there was no difference in age, rate of ACS presentation, burden of comorbidities, or left ventricular ejection fraction. There were no differences in in-hospital adverse events between the 2 groups. At 12 months, MACE occurred more frequently with ULM PCI compared with PLM PCI (25% [334] vs 20% [270]; P = 0.004), and all-cause mortality was also higher (18% [239] vs 14% [185]; P = 0.005). There was no difference in rehospitalization for MI, stroke, or revascularization at 12 months. Conclusion: In the VA Healthcare System, patients undergoing ULM PCI were older and more clinically complex than those undergoing PLM PCI. In the propensity-matched cohort, patients undergoing PLM PCI had better 12 outcomes than those undergoing ULM PCI, but there was a high rate of mortality and MACE at 1 year in both groups, despite a relatively low rate of MI or revascularization

    Effects of internal luminescence and internal optics on V-oc and J(sc) of III-V solar cells

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    For solar cells dominated by radiative recombination, the performance can be significantly enhanced by improving the internal optics. Internally radiated photons can be directly emitted from the cell, but if confined by good internal reflectors at the front and back of the cell they can also be re-absorbed with a significant probability. This so-called photon recycling leads to an increase in the equilibrium minority carrier concentration and therefore the open-circuit voltage, Voc. In multijunction cells, the internal luminescence from a particular junction can also be coupled into a lower bandgap junction where it generates photocurrent in addition to the externally generated photocurrent, and affects the overall performance of the tandem. We demonstrate and discuss the implications of a detailed model that we have developed for real, non-idealized solar cells that calculates the external luminescent efficiency, accounting for wavelength-dependent optical properties in each layer, parasitic optical and electrical losses, multiple reflections within the cell and isotropic internal emission. The calculation leads to Voc, and we show data on high quality GaAs cells that agree with the trends in the model as the optics are systematically varied. For multijunction cells the calculation also leads to the luminescent coupling efficiency, and we show data on GaInP/GaAs tandems where the trends also agree as the coupling is systematically varied. In both cases, the effects of the optics are most prominent in cells with good material quality. The model is applicable to any solar cell for which the optical properties of each layer are well-characterized, and can be used to explore a wide phase space of design for single junction and multijunction solar cells

    Functional and Safety Outcomes of Carotid Artery Stenting and Mechanical Thrombectomy for Large Vessel Occlusion Ischemic Stroke With Tandem Lesions

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    Arteria carótida; Trombectomía mecánica; Accidente cerebrovascular isquémicoArtèria caròtida; Trombectomia mecànica; Accident cerebrovascular isquèmicCarotid artery; Mechanical thrombectomy; Ischemic strokeImportance Approximately 10% to 20% of large vessel occlusion (LVO) strokes involve tandem lesions (TLs), defined as concomitant intracranial LVO and stenosis or occlusion of the cervical internal carotid artery. Mechanical thrombectomy (MT) may benefit patients with TLs; however, optimal management and procedural strategy of the cervical lesion remain unclear. Objective To evaluate the association of carotid artery stenting (CAS) vs no stenting and medical management with functional and safety outcomes among patients with TL-LVOs. Design, Setting, and Participants This cross-sectional study included consecutive patients with acute anterior circulation TLs admitted across 17 stroke centers in the US and Spain between January 1, 2015, and December 31, 2020. Data analysis was performed from August 2021 to February 2022. Inclusion criteria were age of 18 years or older, endovascular therapy for intracranial occlusion, and presence of extracranial internal carotid artery stenosis (>50%) demonstrated on pre-MT computed tomography angiography, magnetic resonance angiography, or digital subtraction angiography. Exposures Patients with TLs were divided into CAS vs nonstenting groups. Main Outcomes and Measures Primary clinical and safety outcomes were 90-day functional independence measured by a modified Rankin Scale (mRS) score of 0 to 2 and symptomatic intracranial hemorrhage (sICH), respectively. Secondary outcomes were successful reperfusion (modified Thrombolysis in Cerebral Infarction score ≥2b), discharge mRS score, ordinal mRS score, and mortality at 90 days. Results Of 685 patients, 623 (mean [SD] age, 67 [12.2] years; 406 [65.2%] male) were included in the analysis, of whom 363 (58.4%) were in the CAS group and 260 (41.6%) were in the nonstenting group. The CAS group had a lower proportion of patients with atrial fibrillation (38 [10.6%] vs 49 [19.2%], P = .002), a higher proportion of preprocedural degree of cervical stenosis on digital subtraction angiography (90%-99%: 107 [32.2%] vs 42 [20.5%], P < .001) and atherosclerotic disease (296 [82.0%] vs 194 [74.6%], P = .003), a lower median (IQR) National Institutes of Health Stroke Scale score (15 [10-19] vs 17 [13-21], P < .001), and similar rates of intravenous thrombolysis and stroke time metrics when compared with the nonstenting group. After adjustment for confounders, the odds of favorable functional outcome (adjusted odds ratio [aOR], 1.67; 95% CI, 1.20-2.40; P = .007), favorable shift in mRS scores (aOR, 1.46; 95% CI, 1.02-2.10; P = .04), and successful reperfusion (aOR, 1.70; 95% CI, 1.02-3.60; P = .002) were significantly higher for the CAS group compared with the nonstenting group. Both groups had similar odds of sICH (aOR, 0.90; 95% CI, 0.46-2.40; P = .87) and 90-day mortality (aOR, 0.78; 95% CI, 0.50-1.20; P = .27). No heterogeneity was noted for 90-day functional outcome and sICH in prespecified subgroups. Conclusions and Relevance In this multicenter, international cross-sectional study, CAS of the cervical lesion during MT was associated with improvement in functional outcomes and reperfusion rates without an increased risk of sICH and mortality in patients with TLs

    Identification of G α 11 as the phospholipase C-activating G-protein of turkey erythrocytes

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    A 43 kDa phospholipase C-activating protein has been purified previously from turkey erythrocytes and shown to express immunological properties expected of that of the Gq family of G-protein alpha-subunits [Waldo, Boyer, Morris and Harden (1991) J. Biol. Chem. 266, 14217-14225]. Internal amino acid sequence has now been obtained from this protein which shares 50-100% sequence identity with sequences encoded by mammalian G alpha 11 and G alpha q cDNAs. To identify the purified protein unambiguously, it was necessary to compare its amino acid sequence with the sequence encoded by avian G-protein alpha-subunit cDNA. As such, mouse G alpha q was used as a probe to screen turkey brain and fetal-turkey blood cDNA libraries. A full-length cDNA was identified that encodes avian G alpha 11, on the basis of its 96-98% amino acid identity with mammalian G alpha 11. All eight peptides sequenced from the turkey erythrocyte phospholipase C-activating protein are completely contained within the deduced amino acid sequence of the avian G alpha 11 cDNA. Expression of this cDNA in Sf9 cells by using a baculovirus expression system resulted in the production of a 43 kDa protein that reacts strongly with antisera to the Gq family of G-protein alpha-subunits and activated purified avian phospholipase C in an AlF4(-)-dependent manner. Taken together, these results unambiguously identify the protein purified from turkey erythrocytes, on the basis of its capacity to activate avian phospholipase C, as G alpha 11

    The optimization of in vitro high-throughput chemical lysis of Escherichia coli. Application to ACP domain of the polyketide synthase ppsC from Mycobacterium tuberculosis

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    Protein production in Escherichia coli involves high-level expression in a culture, followed by harvesting of the cells and finally their disruption, or lysis, to release the expressed proteins. We compare three high-throughput chemical lysis methods to sonication, using a robotic platform and methodologies developed in our laboratory [1]. Under the same expression conditions, all lysis methods varied in the degree of released soluble proteins. With a set of 96 test proteins, we used our split GFP to quantify the soluble and insoluble protein fractions after lysis. Both the amount of soluble protein and the percentage recovered in the soluble fraction using SoluLyse® were well correlated with sonication. Two other methods, Bugbuster® and lysozyme, did not correlate well with sonication. Considering the effects of lysis methods on protein solubility is especially important when accurate protein solubility measurements are needed, for example, when testing adjuvants, growth media, temperature, or when establishing the effects of truncation or sequence variation on protein stability

    Mechanically stacked four-junction concentrator solar cells

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    Multijunction solar cells can be fabricated by bonding together component cells that are grown separately. Because the component cells are each grown lattice-matched to suitable substrates, this technique allows alloys of different lattice constants to be combined without the structural defects introduced when using metamorphic buffers. Here we present results on the fabrication and performance of four-junction mechanical stacks composed of GaInP/GaAs and GaInAsP/GaInAs tandems, grown on GaAs and InP substrates, respectively. The two tandems were bonded together with a lowindex, transparent epoxy that acts as an omni-directional reflector to the GaAs bandedge luminescence, while simultaneously transmitting nearly all of the sub-bandgap light. As determined by electroluminescence measurements and optical modeling, the GaAs subcell demonstrates a higher internal radiative limit and thus higher subcell voltage, compared with GaAs subcells without enhanced internal optics; all four subcells exhibit excellent material quality. The device was fabricated with four contact terminals so that each tandem can be operated at its maximum power point, which raises the cumulative efficiency and decreases spectral sensitivity. Efficiencies exceeding 38% at one-sun have been demonstrated. Eliminating the series resistance is the key challenge for the concentrator cells. We will discuss the performance of one-sun and concentrator versions of the device, and compare the results to recently fabricated monolithic four-junction cells

    URBAN TERRAIN CLIMATOLOGY AND REMOTE SENSING *

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    . Urban areas have been conceived of as monolithic heat islands because traditional ground observation techniques do not lend themselves to more specific analyses. Observations of urban energy-exchange obtained from calibrated electro-optical scanners combined with energy budget simulation techniques provide tools to relate the urban land use mosaic to the heat island phenomenon. Maps of surface energy-related phenomena were made from airborne scanner outputs for selected flightpaths across the city of Baltimore, Maryland. Conditions for the flight time were simulated according to the various types of land use using an energy budget simulation model which lends itself to extrapolation of simulated grid-point conditions into a map form. Maps made by simulation compare sufficiently well with those made by aerial observation to encourage further refinement of the simulation approach.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72392/1/j.1467-8306.1976.tb01110.x.pd
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