Unwrapping the Deadweight Loss of Gift Giving

anonymous referees of this journal and seminar participants at Ben-Gurion University, Universite Louis-Pasteur and the 1998 ESA meetings in Mannheim for comments. Unwrapping the Deadweight Loss of Gift Giving Two previous surveys used to measure the welfare implications of Christmas gift giving in the U.S. have reached opposite conclusions. Waldfogel (1993) nds a 10-33 % welfare reduction associated with Christmas giving. Curiously, Solnick and Hemenway's (1996) (henceforth S&H) replication of Waldfogel's survey turns up just the opposite result: a 214 % welfare gain. We design a series of controlled laboratory experiments to determine why thetwopapers arrive at opposite conclusions. We do not produce our own estimate of the deadweight lossofgift giving; rather, our aim is to understand how, and which among, the di erences in methodology between the two studies account for their divergent ndings. Waldfogel (1993) surveyed 58 students enrolled in an intermediate microeconomics class about speci c gifts they had received for Christmas. In addition to eliciting details about the gifts received, the recipient's background, and her relationship to the gift giver, Waldfogel asked recipients to estimate the amount paid by the giver for each gift received. Finally, recipients were asked to place avalue on each gift they received. Respondents were instructed to estimate the value of a gift as the...amountofcashsuch that you are indi erent between the gift and the cash, not counting the sentimental value of the gift. (Waldfogel, 1993, p.1331) Waldfogel measures the welfare yield of a gift as the di erence between the re-1 cipient's valuation and her cost estimate of the gift. Based on 278 gifts reported, Waldfogel nds that gifts have anaverage yield of 87.1%, indicating that gifts lose about 13 % of their value in the exchange from giver to receiver. When cash gifts are excluded, the average yield falls further to 83.9%. 1 S&H were intrigued enough byWaldfogel's results to replicate his study. Contrar

Sensory Neuron-Specific GPCR Mrgprs Are Itch Receptors Mediating Chloroquine-Induced Pruritus

The cellular and molecular mechanisms mediating histamine-independent itch in primary sensory neurons are largely unknown. Itch induced by chloroquine (CQ) is a common side effect of this widely used antimalarial drug. Here, we show that Mrgprs, a family of G protein-coupled receptors expressed exclusively in peripheral sensory neurons, function as itch receptors. Mice lacking a cluster of Mrgpr genes display significant deficits in itch induced by CQ but not histamine. CQ directly excites sensory neurons in an Mrgpr-dependent manner. CQ specifically activates mouse MrgprA3 and human MrgprX1. Loss- and gain-of-function studies demonstrate that MrgprA3 is required for CQ responsiveness in mice. Furthermore, MrgprA3-expressing neurons respond to histamine and coexpress gastrin-releasing peptide, a peptide involved in itch sensation, and MrgprC11. Activation of these neurons with the MrgprC11-specific agonist BAM8-22 induces itch in wild-type but not mutant mice. Therefore, Mrgprs may provide molecular access to itch-selective neurons and constitute novel targets for itch therapeutics

Effect of dietary protein restriction on nutritional status in the Modification of Diet in Renal Disease Study

Effect of dietary protein restriction on nutritional status in the Modification of Diet in Renal Disease Study. The safety of dietary protein and phosphorous restriction was evaluated in the Modification of Diet in Renal Disease (MDRD) Study. In Study A, 585 patients with a glomerular filtration rate (GFR) of 25 to 55 ml/min/1.73m2 were randomly assigned to a usual-protein diet (1.3 g/kg/day) or a low-protein diet (0.58 g/kg/day). In Study B, 255 patients with a GFR of 13 to 24 ml/min/1.73m2 were randomly assigned to the low-protein diet or a very-low-protein diet (0.28 g/kg/day), supplemented with a ketoacid-amino acid mixture (0.28 g/kg/day). The low-protein and very-low-protein diets were also low in phosphorus. Mean duration of follow-up was 2.2 years in both studies. Protein and energy intakes were lower in the low-protein and very-low-protein diet groups than in the usual-protein group. Two patients in Study B reached a “stop point” for malnutrition. There was no difference between randomized groups in the rates of death, first hospitalizations, or other “stop points” in either study. Mean values for various indices of nutritional status remained within the normal range during follow-up in each diet group. However, there were small but significant changes from baseline in some nutritional indices, and differences between the randomized groups in some of these changes. In the low-protein and very-low-protein diet groups, serum albumin rose, while serum transferrin, body wt, percent body fat, arm muscle area and urine creatinine excretion declined. Combining patients in both diet groups in each study, a lower achieved protein intake (from food and supplement) was not correlated with a higher rate of death, hospitalization or stop points, or with a progressive decline in any of the indices of nutritional status after controlling for baseline nutritional status and follow-up energy intake. These analyses suggest that the low-protein and very-low-protein diets used in the MDRD Study are safe for periods of two to three years. Nonetheless, both protein and energy intake declined and there were small but significant declines in various indices of nutritional status. These declines are of concern because of the adverse effect of protein calorie malnutrition in patients with end-stage renal disease. Physicians who prescribe low-protein diets must carefully monitor patients' protein and energy intake and nutritional status

The Use of Neural Networks in Identifying Error Sources in Satellite-Derived Tropical SST Estimates

An neural network model of data mining is used to identify error sources in satellite-derived tropical sea surface temperature (SST) estimates from thermal infrared sensors onboard the Geostationary Operational Environmental Satellite (GOES). By using the Back Propagation Network (BPN) algorithm, it is found that air temperature, relative humidity, and wind speed variation are the major factors causing the errors of GOES SST products in the tropical Pacific. The accuracy of SST estimates is also improved by the model. The root mean square error (RMSE) for the daily SST estimate is reduced from 0.58 K to 0.38 K and mean absolute percentage error (MAPE) is 1.03%. For the hourly mean SST estimate, its RMSE is also reduced from 0.66 K to 0.44 K and the MAPE is 1.3%

Minimally Invasive Surgical Approaches and Traditional Total Hip Arthroplasty: A Meta-Analysis of Radiological and Complications Outcomes

BACKGROUND: Minimally invasive total hip arthroplasty (MITHA) remains considerably controversial. Limited visibility and prosthesis malposition increase the risk of post-surgical complications compared to those of the traditional method. METHODS: A meta-analysis was undertaken of all published databases up to May 2011. The studies were divided into four subgroups according to the surgical approach taken. The radiological outcomes and complications of minimally invasive surgery were compared to traditional total hip arthroplasty (TTHA) using risk ratio, mean difference, and standardized mean difference statistics. RESULTS: In five studies involving the posterolateral approach, no significant differences were found between the MITHA groups and the TTHA groups in the acetabular cup abduction angle (p = 0.41), acetabular anteversion (p = 0.96), and femoral prosthesis position (p = 0.83). However, the femoral offset was significantly increased (WMD = 3.00; 95% CI, 0.40-5.60; p = 0.02). Additionally, there were no significant differences among the complications in both the groups (dislocations, nerve injury, infection, deep vein thrombosis, proximal femoral fracture) and revision rate (p>0.05). In three studies involving the posterior approach, there were no significant differences in radiological outcomes or all other complications between MITHA or TTHA groups (p>0.05). Three studies involved anterolateral approach, while 2 studies used the lateral approach. However, the information from imaging and complications was not adequate for statistical analysis. CONCLUSIONS: Posterior MITHA seems to be a safe surgical procedure, without the increased risk of post-operative complication rates and component malposition rates. The posterolateral approach THA may lead to increased femoral offset. The current data are not enough to reach a positive conclusion that lateral and anterolateral approaches will result in increased risks of adverse effects and complications at the prosthesis site

The Changing Face of Neolithic and Bronze Age Ireland: A Big Data Approach to the Settlement and Burial Records

This paper synthesizes and analyses the spatial and temporal patterns of archaeological sites in Ireland spanning the Neolithic period and the Bronze Age transition (4300-1900 cal BC). Included are a large number of unpublished, newly discovered sites excavated through development-led projects. Data were also sourced from national archives, published excavation reports and on-line databases. Software tools were developed to deal with the varying nature and resolution of these datasets, allowing chronology to be considered in the analysis to a degree that is usually not possible in prehistoric studies. Summed radiocarbon probabilities are used to examine the dataset using context- and sample-sensitive approaches. Visualisations of spatial and chronological data illustrate the expansion of Early Neolithic settlement, followed by an apparent attenuation of all settlement activity. The Late Neolithic and Chalcolithic periods are characterised by a resurgence and diversification of activity. To assess the significance of these observations, Irish radiocarbon data are compared to an idealized model derived from North American data. Even after taking various considerations into account, human population increases can be suggested to have occurred during the Early and Late Neolithic periods. Gaps and biases in the data are discussed and priorities for future work are identified

A Multicenter Evaluation of Diagnostic Tools to Define Endpoints for Programs to Eliminate Bancroftian Filariasis

Successful mass drug administration (MDA) campaigns have brought several countries near the point of Lymphatic Filariasis (LF) elimination. A diagnostic tool is needed to determine when the prevalence levels have decreased to a point that MDA campaigns can be discontinued without the threat of recrudescence. A six-country study was conducted assessing the performance of seven diagnostic tests, including tests for microfilariae (blood smear, PCR), parasite antigen (ICT, Og4C3) and antifilarial antibody (Bm14, PanLF, Urine SXP). One community survey and one school survey were performed in each country. A total of 8,513 people from the six countries participated in the study, 6,443 through community surveys and 2,070 through school surveys. Specimens from these participants were used to conduct 49,585 diagnostic tests. Each test was seen to have both positive and negative attributes, but overall, the ICT test was found to be 76% sensitive at detecting microfilaremia and 93% specific at identifying individuals negative for both microfilariae and antifilarial antibody; the Og4C3 test was 87% sensitive and 95% specific. We conclude, however, that the ICT should be the primary tool recommended for decision-making about stopping MDAs. As a point-of-care diagnostic, the ICT is relatively inexpensive, requires no laboratory equipment, has satisfactory sensitivity and specificity and can be processed in 10 minutes—qualities consistent with programmatic use. Og4C3 provides a satisfactory laboratory-based diagnostic alternative

A phase III clinical trial of exercise modalities on treatment side-effects in men receiving therapy for prostate cancer

Background: Androgen deprivation therapy (ADT) is accompanied by a number of adverse side effects including reduced bone mass and increased risk for fracture, reduced lean mass and muscle strength, mood disturbance and increased fat mass compromising physical functioning, independence, and quality of life. The purpose of this investigation is to examine the effects of long term exercise on reversing musculoskeletal-related side effects, and cardiovascular and diabetes risk factors in men receiving androgen deprivation for their prostate cancer. Specifically, we aim to investigate the effects of a 12-month exercise program designed to load the musculoskeletal system and reduce cardiovascular and diabetes disease progression on the following primary endpoints: 1) bone mineral density; 2) cardiorespiratory function and maximal oxygen capacity; 3) body composition (lean mass and fat mass); 4) blood pressure and cardiovascular function; 5) lipids and glycemic control; and 6) quality of life and psychological distress

Arousal of Cancer-Associated Stroma: Overexpression of Palladin Activates Fibroblasts to Promote Tumor Invasion

Background: Cancer-associated fibroblasts, comprised of activated fibroblasts or myofibroblasts, are found in the stroma surrounding solid tumors. These myofibroblasts promote invasion and metastasis of cancer cells. Mechanisms regulating the activation of the fibroblasts and the initiation of invasive tumorigenesis are of great interest. Upregulation of the cytoskeletal protein, palladin, has been detected in the stromal myofibroblasts surrounding many solid cancers and in expression screens for genes involved in invasion. Using a pancreatic cancer model, we investigated the functional consequence of overexpression of exogenous palladin in normal fibroblasts in vitro and its effect on the early stages of tumor invasion. Principal Findings: Palladin expression in stromal fibroblasts occurs very early in tumorigenesis. In vivo, concordant expression of palladin and the myofibroblast marker, alpha smooth muscle actin (a-SMA), occurs early at the dysplastic stages in peri-tumoral stroma and progressively increases in pancreatic tumorigenesis. In vitro introduction of exogenous 90 kD palladin into normal human dermal fibroblasts (HDFs) induces activation of stromal fibroblasts into myofibroblasts as marked by induction of a-SMA and vimentin, and through the physical change of cell morphology. Moreover, palladin expression in the fibroblasts enhances cellular migration, invasion through the extracellular matrix, and creation of tunnels through which cancer cells can follow. The fibroblast invasion and creation of tunnels results from the development o

Heritability enrichment of specifically expressed genes identifies disease-relevant tissues and cell types.

We introduce an approach to identify disease-relevant tissues and cell types by analyzing gene expression data together with genome-wide association study (GWAS) summary statistics. Our approach uses stratified linkage disequilibrium (LD) score regression to test whether disease heritability is enriched in regions surrounding genes with the highest specific expression in a given tissue. We applied our approach to gene expression data from several sources together with GWAS summary statistics for 48 diseases and traits (average N = 169,331) and found significant tissue-specific enrichments (false discovery rate (FDR) < 5%) for 34 traits. In our analysis of multiple tissues, we detected a broad range of enrichments that recapitulated known biology. In our brain-specific analysis, significant enrichments included an enrichment of inhibitory over excitatory neurons for bipolar disorder, and excitatory over inhibitory neurons for schizophrenia and body mass index. Our results demonstrate that our polygenic approach is a powerful way to leverage gene expression data for interpreting GWAS signals