The Costs and Benefits of "Strangers": Why Mixed Communities Are Better

Much of the literature on diversity assumes that individuals have an exogenous "taste for discrimination". In contrast with this approach, we build a model where preferences over the nature of one's community are derived indirectly, and arise because the composition of the community determines the behavior of its members. This allows us to gain a far deeper understanding of the forces that underpin the desirability of diversity or homogeneity within communities. Our main contribution is to show that there are always counteracting forces (heterogeneity involves both costs and benefits), and that, although people prefer to live in communities where their type is majoritarian, they always benefit from having some heterogeneity in the composition of their community.heterogeneity, social interactions, value of information, complementarities.

An Economic Theory of the Glass Ceiling

The glass ceiling is one of the most controversial and emotive aspects of employment in organisations. This paper provides a model of the glass ceiling that exhibits the following features that are frequently thought to characterise the problem: (i) there is a lower number of female employees in higher positions, (ii) women have to work harder than men to obtain equivalent jobs, (iii) women are then paid less than men when promoted, and (iv) some organisations are more female friendly than others. These features emerge as an equilibrium phenomenon, when identical firms compete in "Bertrand-like" fashion. Furthermore, they also occur even when offering women the same contract as men in higher positions would be sufficient to ensure that women in those positions would always prefer permanent career over non-market alternatives.Glass Ceiling, Promotions, Career Options

An Economic Theory of Glass Ceiling

In the 'glass ceiling' debate there appear to be two strongly held and opposing interpretations of the evidence, one suggesting it is really the result of gender differences and the other that there is discrimination by gender. This paper provides an economic theory of the glass ceiling and one of the main insights of our analysis is that in some real sense these two interpretations are not in conflict with each other. The glass ceiling emerges as an equilibrium phenomenon when firms compete à la Bertrand even though employers know that offering women the same contract as men would be sufficient to erase all differences among promoted workers. The model also provides new insights into anti-discrimination policy measures. (Updated from working paper 07/183)glass ceilings, promotions, career options

Effects of Perceived Prototype Fidelity in Usability Testing under Different Conditions of Observer Presence

The aim of the study was to investigate the influence of perceived prototype fidelity in usability tests by comparing two prototypes that differed with respect to their perceived proximity to the final system. The impact of the perceived developmental stage of the product was examined for participants' performance, perceived usability, emotions and psychophysiology. Eighty participants were tested, operating an electronic city guide on a mobile phone. In a 2×2×2 mixed design, the system was either presented as an early prototype or as the final system. In addition, observer presence (no observers vs. three observers) and task difficulty (high vs. low) were experimentally manipulated. Overall, the findings did not indicate major differences for perceived prototype fidelity. However, an interaction between the observer presence and prototype fidelity indicated that the observer presence had a more negative impact on the performance when testing a final system than an early prototype. Furthermore, the observer presence resulted in a psychophysiological stress response. The findings suggest that test outcomes are quite robust against different prototype perceptions but that the observer presence needs careful consideratio

First observation of strong OZI rule violation in πN\pi N interactions

The data of the CERN WA56 experiment that triggered the fast proton produced in the $\pi^{+}p$ and $\pi^{-}p$ interactions at beam momenta 20 GeV/c and 12 GeV/c, respectively, are used to analyse the final states $p_{f} \phi (\omega)\pi^{\pm}$. A large excess (up to two orders of magnitude) of the $\phi/\omega$ cross sections ratio over the OZI prediction is observed

Subglottal coupling and vowel space: an investigation in quantal theory.

Thesis (S.B.)—Massachusetts Institute of Technology, Dept. of Physics, 2004.Includes bibliographical references (p. 71-73)This electronic version was prepared by the author. The certified thesis is available in the Institute Archives and Special Collections.NIH Grant DC00075. MIT UROP program.S.B

Parameters of scalar resonances from the combined analysis of data on processes ππ→ππ,KKˉ,ηη\pi\pi\to\pi\pi,K\bar{K},\eta\eta and J/ψJ/\psi decays

A combined analysis of data on isoscalar S-wave processes $\pi\pi\to\pi\pi,K\overline{K},\eta\eta$ and on decays $J/\psi\to\phi\pi\pi,\phi K\overline{K}$ from the DM2, Mark III and BESIII collaborations is performed to study $f_0$ mesons. The method of analysis is based on analyticity and unitarity and uses an uniformization procedure. In the analysis limited only to the multi-channel $\pi\pi$-scattering data, two possible sets of parameters of the $f_0(500)$ were found: in both cases the mass was about 700 MeV but the total width was either about 600 or 930 MeV. The extension of the analysis using only the DM2 and Mark III data on the $J/\psi$ decays does not allow to choose between these sets. However, the data from BESIII on the di-pion mass distribution in the decay $J/\psi\to\phi\pi^+\pi^-$ clearly prefers the wider $f_0(500)$ state. Spectroscopic implications from results of the analysis are also discussed.Comment: the formalism is also described (text overlap) in arXiv:1108.3725; new extended analysis of data; revised PRD versio

Geography and Location Are the Primary Drivers of Office Microbiome Composition.

In the United States, humans spend the majority of their time indoors, where they are exposed to the microbiome of the built environment (BE) they inhabit. Despite the ubiquity of microbes in BEs and their potential impacts on health and building materials, basic questions about the microbiology of these environments remain unanswered. We present a study on the impacts of geography, material type, human interaction, location in a room, seasonal variation, and indoor and microenvironmental parameters on bacterial communities in offices. Our data elucidate several important features of microbial communities in BEs. First, under normal office environmental conditions, bacterial communities do not differ on the basis of surface material (e.g., ceiling tile or carpet) but do differ on the basis of the location in a room (e.g., ceiling or floor), two features that are often conflated but that we are able to separate here. We suspect that previous work showing differences in bacterial composition with surface material was likely detecting differences based on different usage patterns. Next, we find that offices have city-specific bacterial communities, such that we can accurately predict which city an office microbiome sample is derived from, but office-specific bacterial communities are less apparent. This differs from previous work, which has suggested office-specific compositions of bacterial communities. We again suspect that the difference from prior work arises from different usage patterns. As has been previously shown, we observe that human skin contributes heavily to the composition of BE surfaces. IMPORTANCE Our study highlights several points that should impact the design of future studies of the microbiology of BEs. First, projects tracking changes in BE bacterial communities should focus sampling efforts on surveying different locations in offices and in different cities but not necessarily different materials or different offices in the same city. Next, disturbance due to repeated sampling, though detectable, is small compared to that due to other variables, opening up a range of longitudinal study designs in the BE. Next, studies requiring more samples than can be sequenced on a single sequencing run (which is increasingly common) must control for run effects by including some of the same samples in all of the sequencing runs as technical replicates. Finally, detailed tracking of indoor and material environment covariates is likely not essential for BE microbiome studies, as the normal range of indoor environmental conditions is likely not large enough to impact bacterial communities

Assessing the conversion of electronic medical record data into antibiotic stewardship indicators.

BACKGROUND Measuring the appropriateness of antibiotic use is crucial for antibiotic stewardship (ABS) programmes to identify targets for interventions. OBJECTIVES To assess the technical feasibility of converting electronic medical record (EMR) data into ABS indicators. METHODS In this observational feasibility study covering a period of 2 years, the EMRs of patients hospitalized at a large non-university hospital network and receiving at least one dose of a systemic antibiotic were included. ABS indicators measuring steps in the process of antibiotic prescription proposed by the literature were collected and rephrased or defined more specifically to be calculable if needed. Algorithms were programmed in R to convert EMR data into ABS indicators. The indicators were visualized in an interactive dashboard and the plausibility of each output value was assessed. RESULTS In total, data from 25 337 hospitalizations from 20 723 individual patients were analysed and visualized in an interactive dashboard. Algorithms could be programmed to compute 89% (25/28) of all pre-selected indicators assessing treatment decisions automatically out of EMR data, with good data quality for 46% (13/28) of these indicators. According to the data quality observed, the most important issues were (i) missing or meaningless information on indication (e.g. 'mild infection') and (ii) data processing issues such as insufficiently categorized metadata. CONCLUSIONS The calculation of indicators assessing treatment decisions from EMRs was feasible. However, better data structure and processing within EMR systems are crucial for improving the validity of the results