933 research outputs found
Characteristics and Outcomes of Dementia Patients Who Receive Inpatient Palliative Care Consultation
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162727/2/jgs16521_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162727/1/jgs16521.pd
Decarbonylative Cross Coupling of Phthalimides with Diorganozinc Reagents—Efforts Toward Catalysis
The decarbonylative coupling of phthalimides with diorganozinc reagents to form o-substituted benzamides has been previously demonstrated as a viable process, but only with stoichiometric nickel(0). Investigations into a number of reaction variables, including solvent, ligand, and substrate substitution, have yielded multiple sets of conditions capable of achieving up to 10 catalyst turnovers, most successfully with the use of electron withdrawing nitrogen substituents on the phthalimide. In addition, these investigations have provided insight into the intermediates within the catalytic cycle and have revealed new approaches to the development of a general catalytic methodology
Asymmetric Synthesis of α-Keto Esters via Cu(II)-Catalyzed Aerobic Deacylation of Acetoacetate Alkylation Products: An Unusually Simple Synthetic Equivalent to the Glyoxylate Anion Synthon
A simple and efficient method for the preparation of β-stereogenic α-keto esters is described using a copper(II)-catalyzed aerobic deacylation of substituted acetoacetate esters. The substrates for the title process arise from catalytic, enantioselective conjugate additions and alkylation reactions of acetoacetate esters. The mild conditions do not induce racemization of the incipient enolizable α-keto ester. The reaction is tolerant of esters, certain ketones, ketals, and nitro groups and utilizes inexpensive, readily available materials
Catalytic Nucleophilic Glyoxylation of Aldehydes
β-Silyloxy-α-ketoesters are prepared through a cyanide-catalyzed benzoin-type reaction with silyl glyoxylates and aldehydes. The products undergo a dynamic kinetic resolution to provide enantioenriched orthogonally protected alcohols and can be converted to the corresponding β-silyloxy-α-aminoesters
Effects of regional differences and demography in modelling foot-and-mouth disease in cattle at the national scale
Foot-and-mouth disease (FMD) is a fast-spreading viral infection that can produce large and costly outbreaks in livestock populations. Transmission occurs at multiple spatial scales, as can the actions used to control outbreaks. The US cattle industry is spatially expansive, with heterogeneous distributions of animals and infrastructure. We have developed a model that incorporates the effects of scale for both disease transmission and control actions, applied here in simulating FMD outbreaks in US cattle. We simulated infection initiating in each of the 3049 counties in the contiguous US, 100 times per county. When initial infection was located in specific regions, large outbreaks were more likely to occur, driven by infrastructure and other demographic attributes such as premises clustering and number of cattle on premises. Sensitivity analyses suggest these attributes had more impact on outbreak metrics than the ranges of estimated disease parameter values. Additionally, although shipping accounted for a small percentage of overall transmission, areas receiving the most animal shipments tended to have other attributes that increase the probability of large outbreaks. The importance of including spatial and demographic heterogeneity in modelling outbreak trajectories and control actions is illustrated by specific regions consistently producing larger outbreaks than others
Submm/mm Galaxy Counterpart Identification Using a Characteristic Density Distribution
We present a new submm/mm galaxy counterpart identification technique which
builds on the use of Spitzer IRAC colors as discriminators between likely
counterparts and the general IRAC galaxy population. Using 102 radio- and
SMA-confirmed counterparts to AzTEC sources across three fields (GOODS-N,
GOODS-S, and COSMOS), we develop a non-parametric IRAC color-color
characteristic density distribution (CDD), which, when combined with positional
uncertainty information via likelihood ratios, allows us to rank all potential
IRAC counterparts around SMGs and calculate the significance of each ranking
via the reliability factor. We report all robust and tentative radio
counterparts to SMGs, the first such list available for AzTEC/COSMOS, as well
as the highest ranked IRAC counterparts for all AzTEC SMGs in these fields as
determined by our technique. We demonstrate that the technique is free of radio
bias and thus applicable regardless of radio detections. For observations made
with a moderate beamsize (~18"), this technique identifies ~85 per cent of SMG
counterparts. For much larger beamsizes (>30"), we report identification rates
of 33-49 per cent. Using simulations, we demonstrate that this technique is an
improvement over using positional information alone for observations with
facilities such as AzTEC on the LMT and SCUBA-2 on JCMT.Comment: 30 pages, 9 figures, 5 tables. Accepted for publication in MNRA
Secondary Lead Poisoning in Golden Eagle and Ferruginous Hawk Chicks consuming Shot Black-tailed Prairie Dogs, Thunder Basin National Grassland, Wyoming
Recreational shooting of black-tailed prairie dogs (Cynomys ludovicianus) is a common activity at Thunder Basin National Grassland (TBNG), Wyoming. The prairie dog carcasses left in the area are scavenged by coyotes (Canis latrans), raptors, and other animals. These scavengers are susceptible to lead (Pb) poisoning if they consume Pb bullet fragments or Pb shot when scavenging the shooter-killed prairie dogs. In 2000, a local rehabilitator noted an increase of Pb poisoning cases in raptors (L.Layton, pers. comm. 3/30/01) from the area. We collected several shooter-killed prairie dog carcasses from TBNG for determining if Pb fragments remained embedded in the tissue that potentially would be consumed by raptors. Radiographs showed fragments consistent with Pb to be present. In 2002, we conducted a more in-depth study to determine if Pb poisoning was occurring in raptors at TBNG by documenting the number of raptors on prairie dogs at colonies where shooting occurred, assaying bullet fragments in shot prairie dogs to determine Pb content, and analyzing blood and feather samples of ferruginous hawk (Buteo regalis) and golden eagle (Aquila chrysaetos) nestlings and feathers from burrowing owls (Athene cunicularia) for clinical signs of Pb poisoning.
We observed raptors foraging at prairie dog colonies and collected data on the number of shooters shooting at prairie dog colonies. To determine if raptors preferred foraging on shot prairie dogs, we compared raptor use at prairie dog colonies where shooting occurred to raptor use at prairie dog colonies where shooting did not occur. Shooter intensity did not predict raptor use. We also collected prairie dog carcasses and examined them for Pb shot fragments. We detected metal fragments in four of ten prairie dog carcasses. The total weight of the fragments found in each carcass ranged from 10 – 146 mg. Copper was the primary metal detected in 3 of 4 carcasses; but, significant amounts of Pb (20 mg, 28 mg, and 124 mg) were found in the three carcasses. Blood Pb concentrations in ferruginous hawk nestlings were below sub-clinical levels at TBNG and the control site near Rawlins, Wyoming. Analysis of red blood cell delta-aminolevulinic acid dehydratase activity, hemoglobin levels, and protoporphyrin levels also did not indicate Pb poisoning in ferruginous hawk nestlings. Additionally, blood and feather samples from golden eagle nestlings and feather samples from burrowing owls (juveniles and adults) at TBNG did not indicate Pb poisoning. Although ferruginous hawks and golden eagles (and possibly burrowing owls) scavenge on the carcasses of shot prairie dogs and some carcasses contained Pb-bullet fragments, we did not detect Pb poisoning in any of the birds. Lead poisoning may become important if the availability of alternate food sources decreases or shooter intensity increases
ChemInform Abstract: Dynamic Kinetic Resolution of α-Keto Esters via Asymmetric Transfer Hydrogenation.
The dynamic kinetic resolution of β-aryl α-keto esters has been accomplished using a newly designed (arene)RuCl(monosulfonamide) transfer hydrogenation catalyst. This dynamic process generates three contiguous stereocenters with remarkable diastereoselectivity through a reduction/lactonization sequence. The resulting enantioenriched, densely functionalized γ-butyrolactones are of high synthetic utility, as highlighted by several secondary derivatizations
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