Charity Auctions: A Field Experimental Investigation

Auctions are a popular way to raise money for charities, but relatively little is known, either theoretically or empirically, about the properties of charity auctions. The small theoretical literature suggests that the all-pay auction should garner more money than winner-pay auctions. We conduct field experiments to test which sealed bid format, first price, second price or all-pay raises the most money. Our experiment suggests that both the all-pay and second price formats are dominated by the first price auction. Our design also allows us to identify differential participation as the source of the difference between existing theory and the field. To conclude, we show that a model of charity auctions augmented by an endogenous participation decision predicts the revenue ordering that we see in the field.

Endogenous Participation in Charity Auctions

Data from a recent ?eld experiment suggests that differences in participation rates are responsible for much of the variations in revenues across formats in charity auctions. We provide a theoretical framework for the analysis of this, and other related, results. The model illustrates the limits of previous "?xed" results and introduces some new considerations to the choice of auction mechanism. It also implies, however, that the data cannot be explained in terms of participation costs alone: there must exist mechanism-speci?c obstacles to participation.

Moving over mountains: a woman on the Appalachian Trail

This project examines the experience of a woman on the Appalachian Trail. It is my aim in undertaking this project to evaluate my own personal experiences in order to explore the way the Appalachian Trail is conceptualized as a space, and then experienced as a place. My own experiences will be connected to and contrasted by experiences I have with other hikers. It is through my own experiences and those of others that I hope to highlight the ways that spaces and mobilities are gendered in our society and the ways that those expectations are usurped. The wilderness might be one of the last places in the United States considered by many to be male dominated physically and ideologically. While this might be enough to keep some women away from the trail, the women thru hiking the trail have given up on that notion and embarked on a six month long journey into an imagined unknown and an actually well charted territory. Understanding more about how gendered spaces are negotiated within the space itself will further our understanding of the ways that conceptualizations are adapted to meet with experience. After all, ideology and practice do not always match up. Just because there is an understood rule or set of expectations does not stop people from pushing the limits and overturning the conceptions. I believe that for the women walking on the trail, they have successfully overcome the expectations and made a place of their own

Ethnic Racial Socialization Among Inracial International Adoptive Placements

Parents of international adoptees are encouraged to provide ethnic socialization for their children. Retrospective evidence from adult adoptees suggests this is important for identity development, particularly among transracially adopted persons. However little is known about ethnic identity development among children placed internationally in in-racial placements. It is unknown whether a focus on ethnic socialization by the adoptive family might further distinguish an adopted child as different, or relate to an adoptee’s increased perception of adoption visibility. The current study examined the ethnic identity development of 31 adoptees ages 11-18 in in-racial international adoptive placements. Adoption visibility, perceived self-competence, and affiliation with the adoptee’s country-of-origin ethnic group and the adoptive family’s ethnic group were assessed using an online questionnaire. The survey was completed by both the adoptee and the adoptive parent. Analyses of responses indicates that the majority of adoptees do not feel highly visible with respect to physical dissimilarity and have positive feelings about adoption and their birth countries. The vast majority of parents indicate that they have provided the right amount of exposure to the adoptee’s culture of origin. However, adoptees who affiliate more strongly with the ethnicity and culture of their birth countries have higher perceived self-competence than those who affiliate more strongly with the culture of their adoptive families. This suggests that ethnic socialization is important for all adoptive families regardless of racial identification. Further analysis will explore parental exposure to birth country culture as related to geographic area, as well as other relational factors like parent-child relationship closeness. Implications for policy and practice for families with in-racial placements will be discussed

The orbital motion of the Arches cluster — clues on cluster formation near the galactic center

The Arches cluster is one of the most massive, young clusters in the Milky Way. Located inside the central molecular zone in the inner 200 pc of the Galactic center, it formed in one of the most extreme star-forming environments in the present-day Galaxy. Its young age of only 2.5 Myr allows us to observe the cluster despite the strong tidal shear forces in the inner Galaxy. The orbit of the cluster determines its dynamical evolution, tidal stripping, and hence its fate. We have measured the proper motion of the Arches cluster relative to the ambient field from Keck/NIRC2 LGS-AO and VLT/NAOS-CONICA NGS-AO observations taken 4.3 years earlier. When combined with the radial velocity, we derive a 3D space motion of 232 ± 30 km/s for the Arches. This motion is exceptionally large when compared to molecular cloud orbits in the GC, and places stringent constraints on the formation scenarios for starburst clusters in dense, nuclear environments

Perineuronal Nets in Spinal Motoneurones: Chondroitin Sulphate Proteoglycan around Alpha Motoneurones

Perineuronal nets (PNNs) are extracellular matrix structures surrounding neuronal sub-populations throughout the central nervous system, regulating plasticity. Enzymatically removing PNNs successfully enhances plasticity and thus functional recovery, particularly in spinal cord injury models. While PNNs within various brain regions are well studied, much of the composition and associated populations in the spinal cord is yet unknown. We aim to investigate the populations of PNN neurones involved in this functional motor recovery. Immunohistochemistry for choline acetyltransferase (labelling motoneurones), PNNs using Wisteria floribunda agglutinin (WFA) and chondroitin sulphate proteoglycans (CSPGs), including aggrecan, was performed to characterise the molecular heterogeneity of PNNs in rat spinal motoneurones (Mns). CSPG-positive PNNs surrounded ~70–80% of Mns. Using WFA, only ~60% of the CSPG-positive PNNs co-localised with WFA in the spinal Mns, while ~15–30% of Mnsshowed CSPG-positive but WFA-negative PNNs. Selective labelling revealed that aggrecan encircled ~90% of alpha Mns. The results indicate that (1) aggrecan labels spinal PNNs better than WFA, and (2) there are differences in PNN composition and their associated neuronal populations between the spinal cord and cortex. Insights into the role of PNNs and their molecular heterogeneity in the spinal motor pools could aid in designing targeted strategies to enhance functional recovery post-injury

Why do participants initiate free recall of short lists of words with the first list item? Toward a general episodic memory explanation.

Participants who are presented with a short list of words for immediate free recall (IFR) show a strong tendency to initiate their recall with the 1st list item and then proceed in forward serial order. We report 2 experiments that examined whether this tendency was underpinned by a short-term memory store, of the type that is argued by some to underpin recency effects in IFR. In Experiment 1, we presented 3 groups of participants with lists of between 2 and 12 words for IFR, delayed free recall, and continuous-distractor free recall. The to-be-remembered words were simultaneously spoken and presented visually, and the distractor task involved silently solving a series of self-paced, visually presented mathematical equations (e.g., 3 + 2 + 4 = ?). The tendency to initiate recall at the start of short lists was greatest in IFR but was also present in the 2 other recall conditions. This finding was replicated in Experiment 2, where the to-be-remembered items were presented visually in silence and the participants spoke aloud their answers to computer-paced mathematical equations. Our results necessitate that a short-term buffer cannot be fully responsible for the tendency to initiate recall from the beginning of a short list; rather, they suggest that the tendency represents a general property of episodic memory that occurs across a range of time scales.This is the accepted manuscript. This article may not exactly replicate the final version published in the APA journal. It is not the copy of record. That's available from APA at http://psycnet.apa.org/journals/xlm/40/6/1551/

Properties of the Remnant Clockwise Disk of Young Stars in the Galactic Center

We present new kinematic measurements and modeling of a sample of 116 young stars in the central parsec of the Galaxy in order to investigate the properties of the young stellar disk. The measurements were derived from a combination of speckle and laser guide star adaptive optics imaging and integral field spectroscopy from the Keck telescopes. Compared to earlier disk studies, the most important kinematic measurement improvement is in the precision of the accelerations in the plane of the sky, which have a factor of six smaller uncertainties (~10 uas/yr/yr). We have also added the first radial velocity measurements for 8 young stars, increasing the sample at the largest radii (6"-12") by 25%. We derive the ensemble properties of the observed stars using Monte-Carlo simulations of mock data. There is one highly significant kinematic feature (~20 sigma), corresponding to the well-known clockwise disk, and no significant feature is detected at the location of the previously claimed counterclockwise disk. The true disk fraction is estimated to be ~20%, a factor of ~2.5 lower than previous claims, suggesting that we may be observing the remnant of what used to be a more densely populated stellar disk. The similarity in the kinematic properties of the B stars and the O/WR stars suggests a common star formation event. The intrinsic eccentricity distribution of the disk stars is unimodal, with an average value of = 0.27 +/- 0.07, which we show can be achieved through dynamical relaxation in an initially circular disk with a moderately top-heavy mass function.Comment: 65 pages, 22 figures, 8 tables, submitted to Ap