Advertiser Learning in Direct Advertising Markets

Direct buy advertisers procure advertising inventory at fixed rates from publishers and ad networks. Such advertisers face the complex task of choosing ads amongst myriad new publisher sites. We offer evidence that advertisers do not excel at making these choices. Instead, they try many sites before settling on a favored set, consistent with advertiser learning. We subsequently model advertiser demand for publisher inventory wherein advertisers learn about advertising efficacy across publishers' sites. Results suggest that advertisers spend considerable resources advertising on sites they eventually abandon -- in part because their prior beliefs about advertising efficacy on those sites are too optimistic. The median advertiser's expected CTR at a new site is 0.23%, five times higher than the true median CTR of 0.045%. We consider how pooling advertiser information remediates this problem. Specifically, we show that ads with similar visual elements garner similar CTRs, enabling advertisers to better predict ad performance at new sites. Counterfactual analyses indicate that gains from pooling advertiser information are substantial: over six months, we estimate a median advertiser welfare gain of \$2,756 (a 15.5% increase) and a median publisher revenue gain of \$9,618 (a 63.9% increase)

Isolation and characterization of buccal fat pad and dental pulp mscs from the same donor

Mesenchymal stem cells (MSCs) can be harvested from different sites in the oral cavity, representing a reservoir of cells useful for regenerative purposes. As direct comparisons between at least two types of MSCs deriving from the same patient are surprisingly rare in scientific literature, we isolated and investigated the osteoinductive potential of dental pulp stem cells (DPSCs) and buccal fat pad stem cells (BFPSCs). MSCs were isolated from the third molar dental pulp and buccal fat pads of 12 patients. The number of viable cells was quantified through manual count. Proliferation and osteodifferentiation assays, flow cytometry analysis of cell phenotypes, and osteocalcin release in vitro were performed. The isolation of BFPSCs and DPSCs was successful in 7 out of 12 (58%) and 3 out of 12 (25%) of retrieved samples, respectively. The yield of cells expressing typical stem cell markers and the level of proliferation were higher in BFPSCs than in DPSCs. Both BFP-SCs and DPSCs differentiated into osteoblast-like cells and were able to release a mineralized matrix. The release of osteocalcin, albeit greater for BFPSCs, did not show any significant difference between BFPSCs and DPSCs. The yield of MSCs depends on their site of origin as well as on the protocol adopted for their isolation. Our data show that BFP is a valuable source for the derivation of MSCs that can be used for regenerative treatments

Comorbidities in rheumatoid arthritis: analysis of hospital discharge records

Objective: Arthritis is often associated with comorbidities. For many of them, such as hypertension, cardiovascular disease, chronic pulmonary disease, and upper gastrointestinal disease, arthritis and its treatment may also represent a risk factor. This study is concerned with an evaluation of the frequency of comorbidities in a cohort of patients with rheumatoid arthritis (RA). Methods: The discharge diagnoses of patients with RA during the period 1 January 1997 to 31 December 2000 were retrieved from the database of the Department of Internal Medicine of the University of Genova, Italy. The diagnosis of RA was made if the patient's discharge record contained the code 714 of the International Classification of Diseases, IX revision, as first 3 numbers. The other diagnoses were also recorded along with demographic data, type and duration of hospital stay, and performed procedures. Results: During the study period, 427 patients with RA were admitted to the hospital for a total number of 761 admissions, which represented 2.2% of total admissions. Ninety-one (21.3%) patients did not have comorbidities, whereas 336 (78.6%) had one or more comorbidities. The most frequently observed comorbidities were cardiovascular diseases (34.6%), including hypertension (14.5%) and angina (3.5%), followed by gastrointestinal (24.5%), genito-urinary (18.7%) and respiratory (17%) diseases. There was a male predominance (p=0.004) within patients with comorbidities, who were significantly older (64.2±3.2 years vs. 57.2±4.2 years; p<0.001) and required longer periods of hospital stay (22.7 days vs. 12.5 days; p<0.001). Conclusions: Comorbidities are present in nearly 80% of RA inpatients. Comorbidity is a good predictor of health outcome, health services utilization, and medical costs. Because RA comorbidity can act as confounder, it should be considered in epidemiologic studies and clinical trials

Super-condenser enables labelfree nanoscopy.

Labelfree nanoscopy encompasses optical imaging with resolution in the 100 nm range using visible wavelengths. Here, we present a labelfree nanoscopy method that combines coherent imaging techniques with waveguide microscopy to realize a super-condenser featuring maximally inclined coherent darkfield illumination with artificially stretched wave vectors due to large refractive indices of the employed Si3N4 waveguide material. We produce the required coherent plane wave illumination for Fourier ptychography over imaging areas 400 μm2 in size via adiabatically tapered single-mode waveguides and tackle the overlap constraints of the Fourier ptychography phase retrieval algorithm two-fold: firstly, the directionality of the illumination wave vector is changed sequentially via a multiplexed input structure of the waveguide chip layout and secondly, the wave vector modulus is shortend via step-wise increases of the illumination light wavelength over the visible spectrum. We test the method in simulations and in experiments and provide details on the underlying image formation theory as well as the reconstruction algorithm. While the generated Fourier ptychography reconstructions are found to be prone to image artefacts, an alternative coherent imaging method, rotating coherent scattering microscopy (ROCS), is found to be more robust against artefacts but with less achievable resolution

Pediatric Critical Care Transfusion and Anemia Expertise Initiative

Introduction/Hypothesis: Despite evidence that a lower hemoglobin threshold is safe in hemodynamically stable children, studies have shown that transfusion thresholds in practice are higher, exposing these children to the morbidity and mortality associated with RBC transfusion. Therefore, there is increased need for evidence-based blood management strategies for clinicians caring for critically ill children. Methods: The Pediatric Critical Care Transfusion and Anemia Expertise Initiative has brought together a group of 49 international experts in pediatric transfusion/critical care in collaboration with the Pediatric Critical Care Blood Research Network (BloodNet), and the Pediatric Acute Lung Injury and Sepsis Investigators (PALISI), to conduct a consensus conference series on pediatric critical care blood management. The methodology is modeled after that used in the Pediatric Acute Lung Injury and Consensus Conference and will create consensus statements via a structured process outlining existing data in RBC transfusion. Novel features include engagement with implementation science experts to enable consensus uptake. Results: Two of the three expert meetings have been successfully conducted. Ten topics were identified and include recommendations on indications for RBC transfusion in critically ill children 1) based on hemoglobin triggers in the general population, 2) based on physiological triggers in the general population, 3) traumatic brain injury, 4) congenital heart disease, 5) hematologic/oncologic disease, 6) respiratory failure, 7) shock, 8) bleeding, 9) extracorporeal support, and 10) alternative processing. The systematic review was performed. The short text recommendations were generated, discussed at the second meeting and will undergo voting using the RAND UCLA Appropriateness Method to achieve consensus. Conclusions: The TAXI consensus series is the first consensus series to convene international and multidisciplinary experts to create consensus statements on transfusion practices to improve outcomes and safety for critically ill children at risk for, or who require, RBC transfusions

Hematologic and hepatic responses of the freshwater fish Hoplias malabaricus after saxitoxin exposure.

The bioaccumulation of saxitoxins (STX) in the trophic chain, mainly in freshwater, are not completely known. This work aimed to elucidate the effects of STX on Hoplias malabaricus through trophic bioassay. The fish were fed once every five days with Astyanax sp. before being subjected to an intraperitoneal inoculation with the lysate of Cylindrospermopsis raciborskii culture containing 97% STX and 3% by neosaxitoxin and gonyautoxin during 20 days. The animal?s liver was assessed using biomarkers as activities of superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutathione peroxidase (GPx), and concentrations of reduced glutathione (GSH) and lipoperoxidation (LPO) and protein carbonylation (PCO). In the blood was analyzed the genotoxic and hematological parameters. The hepatosomatic index and the relative condition factor did not show a significant difference between the exposed and control groups. The values of mean corpuscular hemoglobin concentration and mean corpuscular hemoglobin increased in the STX group. The hepatic tissue from both groups exhibited a typical pattern that have been already described for most teleost fish. The results suggested the generation of reactive oxygen species, with increased activity of GPx and concentrations of LPO and GSH; whereas the specific activity of SOD decreased. However, no changes were observed in the CAT, PCO, and DNA damage. Although the STX effects are known as neurotoxic, this cyanotoxin caused liver biochemical alterations that can be considered ecologically relevant

A rapid controller of temperature for use in determining Arrhenius profiles in biomembrane systems

To minimize artifacts in temperature-velocity (Arrhenius) profiles due to aging of preparations of biological membranes, a rapid controller of temperature was developed for spectrophotometric or polarographic (O 2 electrode) measurements. The reaction mixture is cooled or heated through contact with Peltier elements. One Pt temperature sensor in the cuvette or electrode holder controls current flow into the Peltier units, and another Pt temperature sensor in the reaction mixture is used to read out the sample temperature on a meter or recorder, and to provide feedback control. The sample temperature can be reproducibly set to within 0.1°C, with a noise level of 0.04°C or less; a change of 4°C takes 1 min.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44794/1/10863_2004_Article_BF00744744.pd