Depositional History of the St. Joe and Boone Formations in Northern Arkansas

The Kinderhookian-Osagean (Lower Mississippian) St. Joe and Boone Limestone represent an unconformity bounded transgressive-regressive sequence widely distributed throughout the southern midcontinent. An irregular erosional surface developed on the Chattanooga Shale (Upper Devonian) or older strata. As Mississippian Seas transgressed, they deposited a thin interval of sandstone, shale, or the two together derived from these old beds. Carbonate deposition was initiated as grain-dominated, crinozoan-bryozoan packstones and grainstones, with subordinate wackestones, and is essentially chert free. These carbonates, referred to as the St. Joe Limestone, reflect a ramp across northern Arkansas that experienced condensed sedimentation and red coloration along its conditions reflected by carbonate mudstones, very fine-grained packstones and grainstones, and penecontemperaneous chert of the overlying lower Boone Formation. The upper Boone (Burlington-Keokuk equivalents) represents a regressive sequence that returned St. Joe-type, grain-dominated, lithologies with diagenetic chert replacement to the shelf. The regression terminated in a pronounced regional unconformity overlain by Meramecian or younger strata

Conservation Conundrum: At-risk Bumble Bees (Bombus spp.) Show Preference for Invasive Tufted Vetch (Vicia cracca) While Foraging in Protected Areas

In recent decades, some bumble bee species have declined, including in North America. Declines have been reported in species of bumble bees historically present in Ontario, including: yellow bumble bee (Bombus fervidus) (Fabricus, 1798), American bumble bee (Bombus pensylvanicus) (DeGeer, 1773), and yellow-banded bumble bee (Bombus terricola) (Kirby, 1837). Threats contributing to bumble bee population declines include: land-use changes, habitat loss, climate change, pathogen spillover, and pesticide use. A response to the need for action on pollinator preservation in North America has been to encourage ‘bee-friendly’ plantings. Previous studies show differences in common and at-risk bumble bee foraging; however, similar data are unavailable for Ontario. Our research question is whether there is a difference in co-occurring at-risk and common bumble bee (Bombus spp.) floral use (including nectar and pollen collection) in protected areas in southern Ontario. We hypothesize that common and at-risk species forage differently, predicting that at-risk species forage on a limited selection of host plants. We conducted a field survey of sites in southern Ontario, using observational methods to determine bumble bee foraging by species. The results of a redundancy analysis show a difference in foraging between common and at-risk bumblebee species. At-risk bumble bee species show a preference for foraging on invasive, naturalized Vicia cracca (tufted vetch). This finding raises the question of how to preserve or provide forage for at-risk bumble bees, when they show an association with an invasive species often subject to control in protected areas.York University Librarie

A gradient index metamaterial

Metamaterials--artificially structured materials with tailored electromagnetic response--can be designed to have properties difficult to achieve with existing materials. Here we present a structured metamaterial, based on conducting split ring resonators (SRRs), which has an effective index-of-refraction with a constant spatial gradient. We experimentally confirm the gradient by measuring the deflection of a microwave beam by a planar slab of the composite metamaterial over a broad range of frequencies. The gradient index metamaterial represents an alternative approach to the development of gradient index lenses and similar optics that may be advantageous, especially at higher frequencies. In particular, the gradient index material we propose may be suited for terahertz applications, where the magnetic resonant response of SRRs has recently been demonstrated

College Students’ Personality Traits in Relation to Career Readiness

This study examined sixty-one Gettysburg College juniors and seniors (31 males, 30 females) to measure how the Big Five personality traits, and whether a student has Type D characteristics, determines if a student is career ready. We collected data through an in-person survey, with questions about personality traits, ambition, career readiness, and demographics. Regression was used to statistically analyze our first hypothesis. The results found that there is a significant positive association between conscientiousness and career readiness, but there is no significant association between extraversion and career readiness. For the second hypothesis, a mediation model was used. We found that ambition is not a mediator between Type D personality characteristics and career readiness. However, there is a significant positive association between Type D personality traits and career readiness. We explored whether gender plays a role in ambition responses. We concluded that there were no significant differences between males and females

Coherent energy migration in solids: Determination of the average coherence length in one‐dimensional systems using tunable dye lasers

The coherent nature of energy propagation in solids at low temperatures was established from the time resolved response of the crystal to short optical pulses obtained from a dye laser (pumped by a nitrogen gas laser). The trapping and detrapping of the energy by shallow defects (x traps) was evident in the spectra and enabled us to extract the coherence length: l≳700 Å=186 molecules for the one‐dimensional triplet excitons of 1,2,4,5‐tetrachlorobenzene crystals at T<4.2° K. This length which clearly exceeds the stochastic random walk limit is related to the thermalization mechanisms in this coupled exciton–trap system, and its magnitude supports the notion that exciton–phonon coupling is responsible for the loss of coherence on very long molecular chains (trap concentration is 1/256 000)

Nanoshearing - Collective carbon nanotube micromechanics

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An annotated list and searchable database of works for trumpet and piano by living american composers

One of the hallmarks of a trumpet player’s performing experience is the thrill of playing solo works for trumpet and piano. Many of the works for solo trumpet and piano regularly performed today have long been considered canonical, and given the history of the trumpet, tend to be European in origin, and representative of past compositional trends and pedagogical approaches. Numerous players seek out works written by newer composers to include on solo recitals and juries. However, this is often a difficult endeavor to undertake, as the majority of existing trumpet repertoire databases and search engines contain older works. The purpose of this project was to create an online, searchable database of compositions written for trumpet and piano by living American composers. The site, www.trumpet-rep.org, was created as a resource for trumpet players of all ages and ability levels, as well as music educators, to serve as a guide for choosing appropriate repertoire. The trumpet-rep database can be searched by composer’s name and gender, composition title, range, and number of movements. Other search categories such as the technical challenges/requirements, additional equipment needed, duration of the work, and links to supplementary information for each work are also provided with the search results. Currently, the database includes more than 90 compositions written by 36 composers. This project is ongoing, and works will continue to be added to the database beyond completion of this document

Relational-Interdependence and Life Transitions in College: Study Abroad, First-Year, and International Students

The current study examined the sojourner adjustment of U.S. college students studying abroad, international college students studying in the States, and first-year students adjusting to life in the first semester of their undergraduate careers. An online survey was distributed to 412 college students; it included the Sojourner Adjustment Measure (SAM), the Lifelong Learning Scale (WielkLLS), the Relational-Interdependent Self-Construal Scale (RISC), the Brief HEXACO Inventory of Personality, and the Social Media Use Integration Scale (SMUIS). The purpose of the study was to explore the relationships among major emerging adulthood transitions and various measures of adjustment to college. Results suggest that students tend to report different levels of adjustment at various stages of their academic careers, whether study abroad participants (US and international) or first-year students coming to college for the first tim