A Pilot Study Exploring Gender Differences in Residents’ Strategies for Establishing Mentoring Relationships

BACKGROUND: Mentoring is important throughout a physician's career and has been noted to be particularly important during residency training. Other studies suggest that women may experience difficulty in finding mentors. PURPOSE: This study explored gender-specific differences in residents' mentoring experiences. METHODS: The authors conducted two focus groups at the University of Pittsburgh in July, 2004. One group was composed of 12 female residents; the other was composed of nine male residents. Discussions were audiotaped and transcribed. Two investigators coded the transcripts and identified emerging themes. RESULTS: Residents of both genders cited multiple barriers to mentoring. Men's strategies for finding mentors were more numerous than women's and included identifying mentors through research, similar interests, friendship, and networking. Female strategies were limited and included identifying mentors through "word of mouth" and work experiences. Women described more passive approaches for finding a mentor than men. CONCLUSIONS: Female residents may lack strategies and initiatives for finding mentors. Residency programs should create opportunities for residents to develop mentoring relationships, with special attention paid to gender differences

Two Clusters with Radio-quiet Cooling Cores

Radio lobes inflated by active galactic nuclei at the centers of clusters are a promising candidate for halting condensation in clusters with short central cooling times because they are common in such clusters. In order to test the AGN-heating hypothesis, we obtained Chandra observations of two clusters with short central cooling times yet no evidence for AGN activity: Abell 1650 and Abell 2244. The cores of these clusters indeed appear systematically different from cores with more prominent radio emission. They do not have significant central temperature gradients, and their central entropy levels are markedly higher than in clusters with stronger radio emission, corresponding to central cooling times ~ 1 Gigayear. Also, there is no evidence for fossil X-ray cavities produced by an earlier episode of AGN heating. We suggest that either (1) the central gas has not yet cooled to the point at which feedback is necessary to prevent it from condensing, possibly because it is conductively stabilized, or (2) the gas experienced a major heating event $\gtrsim 1$ Gyr in the past and has not required feedback since then. The fact that these clusters with no evident feedback have higher central entropy and therefore longer central cooling times than clusters with obvious AGN feedback strongly suggests that AGNs supply the feedback necessary to suppress condensation in clusters with short central cooling times.Comment: ApJ Letter, in pres

Evaluation of tip and torque on virtual study models: a validation study

Background: The objectives of this study were to develop and validate a novel analysis protocol to measure linear and angular measurements of tip and torque of each tooth in the dental arches of virtual study models. Methods: Maxillary and mandibular dental casts of 25 subjects with a full permanent dentition were scanned using a three-dimensional model scanner. Sixty points per arch were digitized on each model, five points on each tooth. A custom analysis to measure linear distances and angles of tip and torque was developed using a new reference plane passing as a best-fit among all of the lingual gingival points, with the intermolar lingual distance set as the reference X-axis. The linear distances measured included buccal, lingual, and centroid transverse widths at the level of canines, premolars, and molars as well as arch depth and arch perimeter. Results: There was no systematic error associated with the methodology used. Intraclass correlation coefficient values were higher than 0.70 on every measure. The average random error in the maxilla was 1.5\ub0 \ub1 0.4\ub0 for torque, 1.8\ub0 \ub1 0.5\ub0 for tip, and 0.4 \ub1 0.2 mm for linear measurements. The average random error in the mandible was 1.2\ub0 \ub1 0.3\ub0 for torque, 2.0\ub0 \ub1 0.8\ub0 for tip, and 0.1 \ub1 0.1 mm for the linear measurements. Conclusions: A custom digital analysis protocol to measure traditional linear measurements as well as tip and torque angulation on virtual dental casts was presented. This validation study demonstrated that the digital analysis used in this study has adequate reproducibility, providing additional information and more accurate intra-arch measurements for clinical diagnosis and dentofacial research

The Extended Blue Continuum and Line Emission around the Central Radio Galaxy in Abell 2597

We present results from detailed imaging of the centrally dominant radio elliptical galaxy in the cooling flow cluster Abell 2597, using data obtained with the Wide Field and Planetary Camera 2 (WFPC2) on the Hubble Space Telescope (HST). This object is one of the archetypal "blue-lobed" cooling flow radio elliptical galaxies, also displaying a luminous emission-line nebula, a compact radio source, and a significant dust lane and evidence of molecular gas in its center. We show that the radio source is surrounded by a complex network of emission-line filaments, some of which display a close spatial association with the outer boundary of the radio lobes. We present a detailed analysis of the physical properties of ionized and neutral gas associated with the radio lobes, and show that their properties are strongly suggestive of direct interactions between the radio plasma and ambient gas. We resolve the blue continuum emission into a series of knots and clumps, and present evidence that these are most likely due to regions of recent star formation. We investigate several possible triggering mechanisms for the star formation, including direct interactions with the radio source, filaments condensing from the cooling flow, or the result of an interaction with a gas-rich galaxy, which may also have been responsible for fueling the active nucleus. We propose that the properties of the source are plausibly explained in terms of accretion of gas by the cD during an interaction with a gas-rich galaxy, which combined with the fact that this object is located at the center of a dense, high-pressure ICM can account for the high rates of star formation and the strong confinement of the radio source.Comment: Astrophysical Journal, in press, 34 pages, includes 6 PostScript figures. Latex format, uses aaspp4.sty and epsf.sty file

An infrared survey of brightest cluster galaxies: Paper I

We report on an imaging survey with the Spitzer Space Telescope of 62 brightest cluster galaxies with optical line emission. These galaxies are located in the cores of X-ray luminous clusters selected from the ROSAT All-Sky Survey. We find that about half of these sources have a sign of excess infrared emission; 22 objects out of 62 are detected at 70 microns, 18 have 8 to 5.8 micron flux ratios above 1.0 and 28 have 24 to 8 micron flux ratios above 1.0. Altogether 35 of 62 objects in our survey exhibit at least one of these signs of infrared excess. Four galaxies with infrared excesses have a 4.5/3.6 micron flux ratio indicating the presence of hot dust, and/or an unresolved nucleus at 8 microns. Three of these have high measured [OIII](5007A)/Hbeta flux ratios suggesting that these four, Abell 1068, Abell 2146, and Zwicky 2089, and R0821+07, host dusty active galactic nuclei (AGNs). 9 objects (including the four hosting dusty AGNs) have infrared luminosities greater than 10^11 L_sol and so can be classified as luminous infrared galaxies (LIRGs). Excluding the four systems hosting dusty AGNs, the excess mid-infrared emission in the remaining brightest cluster galaxies is likely related to star formation.Comment: accepted for publication in ApJ

An Observationally Motivated Framework for AGN Heating of Cluster Cores

The cooling-flow problem is a long-standing puzzle that has received considerable recent attention, in part because the mechanism that quenches cooling flows in galaxy clusters is likely to be the same mechanism that sharply truncates the high end of the galaxy luminosity function. Most of the recent models for halting cooling in clusters have focused on AGN heating, but the actual heating mechanism has remained mysterious. Here we present a framework for AGN heating derived from a Chandra survey of gas entropy profiles within cluster cores. This set of observations strongly suggests that the inner parts of cluster cores are shock-heated every ~10^8 years by intermittent AGN outbursts, driven by a kinetic power output of ~ 10^45 erg/sec and lasting at least 10^7 years. Beyond ~30 kpc these shocks decay to sound waves, releasing buoyant bubbles that heat the core's outer parts. Between heating episodes, cooling causes the core to relax toward an asymptotic pure-cooling profile. The density distribution in this asymptotic profile is sufficiently peaked that the AGN shock does not cause a core entropy inversion, allowing the cluster core to retain a strong iron abundance gradient, as observed.Comment: in press, Ap

The Grizzly, February 10, 2005

Project Pericles: Ursinus Students Serving the Community • Break Out Your Microphone and Your Best Spandex: Here Comes Airband • USGA Updates • Burning Question: How to Prevent a Urinary Tract Infection • Literary Side of Music • Red-and-Golds at Ursinus • New Member Education: Three Weeks of Boredom for Non-Greeks? • Opinions: TheFacebook.com, I Hate You: A Victim\u27s Story; How Great is the Nuclear Terror Threat?; Iraqi Election: Why I Really Hate Bush • Wrestling Team Continues Annihilating its Opponents • McGarvey, Smith Rally Bears Past Washington • Daley and Guntli Come up Bighttps://digitalcommons.ursinus.edu/grizzlynews/1577/thumbnail.jp

The Grizzly, February 3, 2005

Students Videoconference with Sri Lanka • Forensics Team Coach-less • Where Have All the Trees Gone? • It\u27s Cold in Here • Learning the Roots and Aspects of Freedom of Expression: Special Topic Course • Contraception and the Y Chromosome: Male Birth Control Options • Influenza: How to Survive the Yearly Epidemic • Where in the World is Your Study Abroad Application? • Opinions: Random Rantings of Racial Relations; Law Should not Justify Artificial Survival • Gymnastics Team Ranked First in Nation • Fourth Time\u27s the Charm • Gaining Ground in the Ranks of the Collegiate Wrestling Worldhttps://digitalcommons.ursinus.edu/grizzlynews/1576/thumbnail.jp

The Grizzly, March 31, 2005

Poem-palooza Tonight • Senior Speaks About Giving Back • Get Amped for Airband! • No Boredom Allowed • Students Petition for Comcast Cable • SERV Members Attend National Conference • Help Hobson Help Others • Ursinus Students Build House During Spring Break • Study Abroad Cancellations • Erectile Dysfunction in Young Men • Experiencing the London Perspective • A New Drink: Water from the Body • Conversation with Mike Ditty • Fitzgerald Returns to Coach Women\u27s Lacrosse • Chemistry is the Ingredient for Success • Men\u27s Lacrosse Team Loses in a Nail-biter to F&Mhttps://digitalcommons.ursinus.edu/grizzlynews/1581/thumbnail.jp

Metabolic state alters economic decision making under risk in humans

Background: Animals' attitudes to risk are profoundly influenced by metabolic state (hunger and baseline energy stores). Specifically, animals often express a preference for risky (more variable) food sources when below a metabolic reference point (hungry), and safe (less variable) food sources when sated. Circulating hormones report the status of energy reserves and acute nutrient intake to widespread targets in the central nervous system that regulate feeding behaviour, including brain regions strongly implicated in risk and reward based decision-making in humans. Despite this, physiological influences per se have not been considered previously to influence economic decisions in humans. We hypothesised that baseline metabolic reserves and alterations in metabolic state would systematically modulate decision-making and financial risk-taking in humans. Methodology/Principal Findings: We used a controlled feeding manipulation and assayed decision-making preferences across different metabolic states following a meal. To elicit risk-preference, we presented a sequence of 200 paired lotteries, subjects' task being to select their preferred option from each pair. We also measured prandial suppression of circulating acyl-ghrelin (a centrally-acting orexigenic hormone signalling acute nutrient intake), and circulating leptin levels (providing an assay of energy reserves). We show both immediate and delayed effects on risky decision-making following a meal, and that these changes correlate with an individual's baseline leptin and changes in acyl-ghrelin levels respectively. Conclusions/Significance: We show that human risk preferences are exquisitely sensitive to current metabolic state, in a direction consistent with ecological models of feeding behaviour but not predicted by normative economic theory. These substantive effects of state changes on economic decisions perhaps reflect shared evolutionarily conserved neurobiological mechanisms. We suggest that this sensitivity in human risk-preference to current metabolic state has significant implications for both real-world economic transactions and for aberrant decision-making in eating disorders and obesity