Characteristics, contexts, and possible functions of the vocalizations of Blue Jays

Many species in the family Corvidae, including Blue Jays (Cyanocitta cristata), are known to have large vocal repertoires. However, perhaps due to its perceived complexity, few investigators have attempted to describe the vocal repertoire of Blue Jays. Therefore, my objectives were to describe the vocal repertoire of Blue Jays, determine the characteristics of their calls, and suggest possible functions. During 2015 and 2016, I studied free-living Blue Jays in and near Richmond, Madison County, Kentucky. I observed Blue Jays at 17 different locations, recorded their vocalizations, and noted the behavioral contexts during which calls were uttered. I also conducted playback experiments with four different Blue Jay calls and with the calls of several species of raptors to provide additional contexts that might provide insight into call function. I recorded 7213 calls uttered during 488 vocal bouts during 103 observation sessions, and identified 40 distinct call types distinguished by their characteristics (peak frequency, high frequency, low frequency, frequency range, and duration). Three call types were only uttered by nestling and fledgling Blue Jays, and two call types were only uttered by adult Blue Jays during playback experiments. Some call types were used more often during either the breeding or non-breeding season and in certain behavioral contexts, suggesting that they served particular functions. However, most call types of adult Blue Jays were used throughout the year and in a variety of behavioral contexts, making it difficult to determine possible functions. Differences in call types used and use of the same calls in different contexts by Blue Jays at different locations suggest that they learn some call types in their vocal repertoires. Further, Blue Jays at different locations or in different flocks may have distinct vocal repertoires and particular calls may serve different functions. A possible explanation for the large vocal repertoire of Blue Jays and other species of birds is the social complexity hypothesis. Species, like Blue Jays, that regularly interact with large numbers of conspecifics in a variety of behavioral contexts are more likely to benefit from having larger vocal repertoires than solitary or less social species. Additional detailed study of species of songbirds with large vocal repertoires, including Blue Jays, will improve our understanding of how such repertoires are used as well as the selective pressures that have favored their evolution

Does It Pay To Attend An Elite Private College? Cross Cohort Evidence on the Effects of College Quality on Earnings

While there is evidence of a substantial and rising labor market premium associated with college attendance, little is known about how this premium varies across institutions of different quality and across time. Previous research which has estimated the return to college quality has not taken into account that individuals likely select the type of college they attend based in part on the expected economic return and net costs. In this paper we explicitly model high school students' choice of college type (characterized by quality and control) based on individual and family characteristics (including ability and parental economic status), and an estimate of the net costs of attendance and expected labor market return. We estimate selectivity corrected outcome equations, using data from both the National Longitudinal Study of the High School Class of 1972 and High School and Beyond, which permit us to determine the effects of college quality on wages and earnings and how this effect varies across time. Even after controlling for selection effects there is strong evidence of significant economic return to attending an elite private institution, and some evidence that this premium has increased over time.

Optimizing Glass Design: The Role of Computational Wind Engineering & Advanced Numerical Analysis

Wind induced pressure is a major design consideration for glazing design. However, the effects of façade geometry and urban terrain on wind loading are often difficult to quantify without costly and time-consuming wind tunnel testing.  Accurate 3-dimensional data, covering most major cities, is becoming increasingly accessible, and such models are ideal to support numerical modelling of environmental effects on the built environment, especially if such modelling attempts to capture the geometric effects of the cityscape.  A new methodology to assess the effects of wind loads on the structural strength of glass using transient, geometrically non-linear analyses and improved glass failure prediction models is presented.  A description is provided for both the calculation of wind-induced façade loads, and the development and employment of a finite element (FE) solver to model façade performance.&nbsp

Penile Rehabilitation Therapy with PDE-V Inhibitors Following Radical Prostatectomy: Proceed with Caution

Penile rehabilitation therapy following radical prostatectomy is a much debated topic. Erectile dysfunction is still a significant contributor to postoperative morbidity following radical prostatectomy, despite meticulous nerve-sparing technique. Secondary smooth muscle changes in the penis have been identified as the underlying causes of penile atrophy, veno-occlusive dysfunction, and fibrosis. Initial observations that intracavernous injection therapies used on a regular basis postoperatively resulted in improvements in the return of spontaneous erectile function led to the development of penile rehabilitation protocols. Chronic dosing of PDE-V inhibitors is now commonly used by urologists after radical prostatectomy. Despite the current enthusiasm of penile rehabilitation therapy, current scientific evidence with clinical trials is still limited

Developing the Civic Skills of Public School Youth: A Mixed Methods Assessment

This study employed mixed methods to examine the experiences of public high school youth (N=126) who participated in youth-designed and youth-led community action over the course of an academic year. The authors explore the development of leadership skills, attitudes toward school-community, and sense of agency. Quantitative findings demonstrate statistically significant changes in youths’ civic attitudes and skills. Qualitative findings provide nuanced understanding of youths’ experiences with responsibility-accountability, confidence-empowerment, perseverance, leadership, mentorship- relationship, and professional skills.

Back to the Drawing Board: Envisioning A Gender-Inclusive Introductory Technology Course

In this new millennium technology permeates everything we do and see. You cannot work, act, or interact in society without using technology. Who is creating and working with this technology? According to Clark (1990) less than 30% of these technology users are female. Unfortunately, this is mirrored in secondary education as well. For example, here are the enrollment statistics for my drafting and engineering classes for the past four years: 1997-1998 School year - 0 females; 1998-1999 School year - 1 female; 1999-2000 School year - 2 females; 2000-2001 School year - 2 females. Since I have roughly 70 - 80 students a year, the female enrollment is a bit under 2% per year, which is unequivocally unacceptable. For whatever reason, females are being excluded from a large, high-paying field and, in this day when gender equity is a byword, females should be embracing technology, not shunning it. Many studies have been done as to why there is a lack of females in mathematics, science, and, to a lesser extent, technology. These studies look at the many factors that influence the development of females, including parents, peers, teachers, and guidance counselors. After reflecting upon what action I, a teacher of technology, might take to help redress this situation, I am proposing to enlist the aid of female students, and area technology teachers in envisioning a gender-inclusive technology curriculum beginning with a redesigning of the first high-school technology course, Design and Drawing for Production. Changing a course or even a curriculum is not enough in itself. First-year female high-school students\u27 perceptions of the course and the curriculum must also change and this change of perception must take into account how helpful these re-envisioned high-school technology courses will be for accessing the many desirable jobs and careers that females will be filling in the near future

Portable high-performance superconducting : high-level platform-dependent optimization

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1994.Includes bibliographical references (p. 163-172).by Eric Allen Brewer.Ph.D