Effects of peer comparisons on low-promotability tasks: Evidence from a university field experiment

Governance—the way rules are set and implemented—in many institutions is sustained through the service of groups of individuals, performing low-promotability tasks. For instance, the success of not-for-profit professional societies, civic organizations, and public universities depends on the willingness of members and employees to serve in governance. Typically service is requested by annual calls to serve. We implement and analyze a field experiment at a large public university using a randomized experimental design, to investigate whether responses to calls to serve are affected by revealing a department's service rankings among its peer departments. We find that revealing a service ranking in the lowest quartile leads to significantly higher response rates than disclosing a median and higher-than-median ranking. Second, beyond informing department heads of their departments’ service rank, directly informing individual faculty members does not have an additional effect on response rates. Third, we show that the treatment effects in the lowest serving quartile are driven by female faculty responses, even though female faculty members were no more likely than their male peers to respond to serve before the experiment. If taking on such tasks is detrimental to promotion, while important for the overall institution, this has implications for the faculty careers of women and men. We discuss potential mechanisms behind the results; formally testing these mechanisms is an area for future research

The calculation of longitude and latitude from geodesic measurements

The solution of the geodesic problem for an oblate ellipsoid is developed in terms of series. Tables are provided to simplify the computation. [This is an English translation of F. W. Bessel, Astronomische Nachrichten 4(86), 241-254 (1825). The mathematical notation has been updated to conform to current conventions and, in a few places, the equations have been rearranged for clarity. Several errors have been corrected, a figure has been included, and the tables have been recomputed.]Comment: 11 pages, including 1 figure and 4 pages of tables. Version 2 and 3 fix some minor errors. This translation was edited by Charles F. F. Karney and Rodney E. Deakin. A transcription of the original paper is available at arXiv:0908.1823 . For links to other 18th and 19th century papers on geodesics, see http://geographiclib.sourceforge.net/geodesic-papers/biblio.htm

Behavioural Mechanisms of Protandrous Spring Migration in a Nearctic-Neotropical Songbird

Most seasonally migrating songbirds have a protandrous migration pattern, meaning that males arrive to the breeding grounds before females. The proximate mechanisms that underlie this pattern are largely unknown for most species. In this thesis, I evaluate the behavioural mechanisms of protandry in the black-throated blue warbler (Setophaga caerulescens) using onset of migratory restlessness as a proxy for departure from the wintering grounds, migratory restlessness intensity as a proxy for motivation to fly, and stopover duration of radio-tagged birds. The onset of migratory restlessness and stopover duration was similar in both sexes. Males displayed higher intensity wing whirring than females, suggesting that protandry might be achieved through sex differences in nocturnal flight duration. Stopover duration was negatively correlated with migratory restlessness intensity on the last night the birds were in captivity, validating migratory restlessness as an accurate proxy for motivation to migrate at the individual level

MHC-linked and un-linked class I genes in the wallaby

Background: MHC class I antigens are encoded by a rapidly evolving gene family comprising classical and non-classical genes that are found in all vertebrates and involved in diverse immune functions. However, there is a fundamental difference between the organization of class I genes in mammals and non-mammals. Non-mammals have a single classical gene responsible for antigen presentation, which is linked to the antigen processing genes, including TAP. This organization allows co-evolution of advantageous class Ia/ TAP haplotypes. In contrast, mammals have multiple classical genes within the MHC, which are separated from the antigen processing genes by class III genes. It has been hypothesized that separation of classical class I genes from antigen processing genes in mammals allowed them to duplicate. We investigated this hypothesis by characterizing the class I genes of the tammar wallaby, a model marsupial that has a novel MHC organization, with class I genes located within the MHC and 10 other chromosomal locations. Results: Sequence analysis of 14 BACs containing 15 class I genes revealed that nine class I genes, including one to three classical class I, are not linked to the MHC but are scattered throughout the genome. Kangaroo Endogenous Retroviruses (KERVs) were identified flanking the MHC un-linked class I. The wallaby MHC contains four non-classical class I, interspersed with antigen processing genes. Clear orthologs of non-classical class I are conserved in distant marsupial lineages. Conclusion: We demonstrate that classical class I genes are not linked to antigen processing genes in the wallaby and provide evidence that retroviral elements were involved in their movement. The presence of retroviral elements most likely facilitated the formation of recombination hotspots and subsequent diversification of class I genes. The classical class I have moved away from antigen processing genes in eutherian mammals and the wallaby independently, but both lineages appear to have benefited from this loss of linkage by increasing the number of classical genes, perhaps enabling response to a wider range of pathogens. The discovery of non-classical orthologs between distantly related marsupial species is unusual for the rapidly evolving class I genes and may indicate an important marsupial specific function

Differential Migration Timing and the Form and Function of Avian Wings

A common differential migration strategy in birds is protandry, whereby males arrive earlier than females. The probable causes of protandry are well studied from the perspective of innate and physical environmental cues, but the influence of the social environment and wing morphology are less known. Theoretical models propose that sex ratio influences protandry; male-biased sex ratios are predicted to advance timing in males due to increased intrasexual competition. To empirically test this, I investigated the spring migration traits of male Yellow-rumped Warblers Setophaga coronata under differing sex ratios. An integrated automated telemetry approach was used, where locomotor movement of captive birds was quantified, followed by the use of Motus Wildlife Tracking System to quantify stopover departure timing post release. Males from the female-biased environment exhibited more locomotor movement and had an earlier onset of migratory restlessness, a proxy for the urge to migrate, suggesting that the composition of the social environment can influence migration behaviour. Next, I assessed the relationship between wing morphology and both differential arrival timing and flight performance in migratory passerines, as pointed wings are theorized to aid level-flight efficiency and impede take-off performance. A long-term migration monitoring dataset revealed that protandry and sexual size dimorphism of wing length co-vary by age, which is believed to reflect a coevolutionary response to sexual selection and viability selection. Larger males may be better able to afford the viability costs of early arrival and younger males may reduce competition with older males by arriving later. Wingtip morphology was characterized using the feather length measurements of 1929 individuals from 18 families and a flight tower was used to determine whether these morphologies influence take-off flight performance. Males, with larger and more convex wingtips, exhibited faster take-off speeds than females. Although older birds had more pointed wingtips than younger birds, this trait did not impact take-off speed. Overall, these findings suggest that males and older birds have competitive advantages and are likely better at escaping predation. Understanding the probable causes of differential migration provides insights on the basic knowledge of avian migration and helps to predict the consequences of future climate change

Non-invasive computer-assisted measurement of knee alignment

The quantification of knee alignment is a routine part of orthopaedic practice and is important for monitoring disease progression, planning interventional strategies, and follow-up of patients. Currently available technologies such as radiographic measurements have a number of drawbacks. The aim of this study was to validate a potentially improved technique for measuring knee alignment under different conditions. An image-free navigation system was adapted for non-invasive use through the development of external infrared tracker mountings. Stability was assessed by comparing the variance (F-test) of repeated mechanical femoro-tibial (MFT) angle measurements for a volunteer and a leg model. MFT angles were then measured supine, standing and with varus-valgus stress in asymptomatic volunteers who each underwent two separate registrations and repeated measurements for each condition. The mean difference and 95% limits of agreement were used to assess intra-registration and inter-registration repeatability. For multiple registrations the range of measurements for the external mountings was 1° larger than for the rigid model with statistically similar variance (p=0.34). Thirty volunteers were assessed (19 males, 11 females) with a mean age of 41 years (range: 20-65) and a mean BMI of 26 (range: 19-34). For intra-registration repeatability, consecutive coronal alignment readings agreed to almost ±1°, with up to ±0.5° loss of repeatability for coronal alignment measured before and after stress maneuvers, and a ±0.2° loss following stance trials. Sagittal alignment measurements were less repeatable overall by an approximate factor of two. Inter-registration agreement limits for coronal and sagittal supine MFT angles were ±1.6° and ±2.3°, respectively. Varus and valgus stress measurements agreed to within ±1.3° and ±1.1°, respectively. Agreement limits for standing MFT angles were ±2.9° (coronal) and ±5.0° (sagittal), which may have reflected a variation in stance between measurements. The system provided repeatable, real-time measurements of coronal and sagittal knee alignment under a number of dynamic, real-time conditions, offering a potential alternative to radiographs