Empirical Limits on Radial Velocity Planet Detection for Young Stars

We report initial results from our long term search using precision radial velocities for planetary-mass companions located within a few AU of stars younger than the Sun. Based on a sample of >150 stars, we define a floor in the radial velocity scatter, sigma_RV, as a function of the chromospheric activity level R'_{HK}. This lower bound to the jitter, which increases with increasing stellar activity, sets the minimum planet mass that could be detected. Adopting a median activity-age relationship reveals the astrophysical limits to planet masses discernable via radial velocity monitoring, as a function of stellar age. Considering solar-mass primaries having the mean jitter-activity level, when they are younger than 100 / 300 / 1000 Myr, the stochastic jitter component in radial velocity measurements restricts detectable companion masses to > 0.3 / 0.2 / 0.1 M_Jupiter. These numbers require a large number -- several tens -- of radial velocity observations taken over a time frame longer than the orbital period. Lower companion mass limits can be achieved for stars with less than the mean jitter and/or with an increased number of observations.Comment: 5 pages, to appear the 18th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun proceedings edited by G. van Belle & H. Harri

Through the wall of literacy: transformative practice in social networks among GCSE re-sit further education students

Purpose The purpose of this paper is to explain how peripheral participants contributed to and became more central members of a community of practice based in a social network that was used to support mobile learning approaches among post-compulsory education students. The notion was that in inducing participation through pedagogical strategies, individualised online presence could be increased that would support studentship, confidence and literacy improvements in participants who are normally apprehensive about online and formal learning contexts. Design/methodology/approach The network was used by four separate groups of 16-19 aged students and 19+ aged adults, with a constant comparison made of their activity and communication. A content analysis was made of students’ posts to the network, with the codes sorted thematically to examine how students used the network to support themselves and each other. Interviews were held with students across the two years to explore perceptions of the network and the community. Findings Peripheral participants navigate through ontological thresholds online to develop individual identity presence online. Increased communicated actions (“posts”) improves participation overall and the interaction of members in terms of developing a community of practice online. The results of communicated actions posted in visible online spaces improved the literacy control and willingness to publish content created by those peripheral participants. Research limitations/implications The study is taken from a small sample (approx. 100 students) in a case study comparing results across four different groups in an English Further Education college. Most of the positive results in terms of an impact being made on their literacy capability was found among adult students, as opposed to students in two 16-19 aged groups. Research implications identify hypothetical stages of identity presence online for reluctant and peripheral participants. This shows the potential of students to be induced to openly participate in visible contexts that can support further identity development. Practical implications The implications show that blended learning is necessary to improve the opportunity for mobile learning to happen. Blended learning in itself is dependent on and simultaneously improves group cohesion of learners in online communities. When students develop a momentum of engagement (and residence within) networks they exploit further technological features and functions and become more co-operative as a group, potentially reducing teacher presence. Learning activities need to support the peripheral participants in discrete and purposeful ways, usually achieved through personalised supported learning tasks. The notion and attention paid to the difficulties in bringing peripheral participants online has implications for the prescription of online learning as a form of delivery, especially among FE students. Social implications This paper problematizes the notion of peripheral participants and suggests they are overlooked in consideration of learning delivery, design and environments. Peripheral participants may be considered to be students who are at risk of not being involved in social organisations, such as communities, and vulnerable to diminished support, for instance through the withdrawal of face-to-face learning opportunities at the expense of online learning. Originality/value This paper makes a small contribution to theories surrounding communities of practice and online learning. By deliberately focusing on a population marginalised in current educational debate, it problematizes the growing prescription of online learning as a mode of delivery by taking the perspectives and experiences of peripheral participants on board

Sport prism

The Sport Prism explores the development and implementation of a cohesive brand identity metaphor for a sport complex across multiple media. The metaphor that significantly impacts the design of this brand is the geometric prism. The concept of geometric prisms is paired with sport imagery to create a unique and compelling brand experience. The Sport Prism frames relationships between the sport complex and the prism in intriguing ways, creating new meaning and ultimately a unique brand identity

Burrowing apparatus

A soil burrowing mole is described in which a housing has an auger blade wound around a front portion. This portion is rotatable about a housing longitudinal axis relative to an externally finned housing rear portion upon operation of driving means to cause an advance through soil and the like. The housing carries a sensor sensitive to deviation from a predetermined path and to which is coupled means for steering the housing to maintain the path

The Museum as an Inclusive Community: A Blueprint for Moving Forward

The focus of this study is museum accessibility for patrons with disabilities. The history of museums and their evolution into institutions that strive to create an inclusive community means that many aspects of the Americans with Disabilities Act of 1990 as well as the Architectural Barriers Act of 1968 are applicable. Developing a tool for assessing museum compliance with the law was key to gathering data to use for improving compliance with the law. Using this data and comparing current compliance in four museums to three major legal cases against museums showed common areas for improvement in accessibility in all facilities involved in this study. Technical solutions for creating an inclusive museum are pulled from legal settlements as well as accessibility websites and presented here

Beef tenderness and management of calf-fed Holstein steers to meet market standards

2013 Summer.Includes bibliographical references.Tenderness is one of the most influential sensory attributes determining consumer acceptance of beef products. Beef at retail represents production of a diverse cattle population, including both beef breeds and cattle bred for milk production. Objectives of this work were to first benchmark tenderness at the retail level and then determine appropriate management strategies to maximize quality and yield of calf-fed Holstein steers. Fifty-four stores in thirty U.S. cities were sampled from June 2011 through May 2012 to benchmark tenderness of beef steaks at retail as assessed by Warner-Bratzler shear force (WBSF).Top loin (N = 980) and sirloin (N = 860) steaks were purchased and shipped via overnight delivery to Colorado State University, Fort Collins, CO. The survey was divided into two periods based on samples shipped fresh and frozen on arrival (Period 1) or samples shipped frozen and stored frozen (Period 2). Mean WBSF values during Period 1 were 2.9 and 3.9 kg for top loin and sirloin steaks, respectively. Frequencies of steaks classified as tough (WBSF ≥ 4.4 kg) were 8.6% and 17.7% for top loin and sirloin steaks, respectively. Examination of coefficients of variation associated with means reflecting the influence of freezing, retail display and shipping suggested that variance remained unchanged (± 2.0%) with respect to shear force values; however, mean shear force values were reduced as a result of shipping conditions. Mean WBSF values during Period 2 were 3.4 and 4.0 kg for top loin and sirloin samples, respectively. Frequencies of steaks classified as tough were 14.3% and 24.8% for top loin and sirloin steaks, respectively. Calf-fed dairy steers comprise approximately 10% of fed-beef harvested in the United States, annually (Moore et al., 2012).This population of cattle is much different genetically and requires use of growth promotants to meet comparable feedlot performance to that of beef breeds. The effect of beta-agonist supplementation on live performance, carcass characteristics, fabrication yields and beef quality of calf-fed Holstein steers was investigated using steers implanted with a combination trenbolone acetate/estradiol based implant and blocked by initial weight into pens (N = 32). Pens consisted of 90 steers each and were randomly assigned to one of four management strategies including: implant only, ractopamine hydrochloride (RH) fed at 300 mg/hd/d for the final 30 d of finishing or RH fed at 400 mg/hd/d for the final 30 d of finishing, and zilpaterol hydrochloride fed at 6.8 g/ton for 23 d with a 3 d withdrawal prior to harvest. Feed efficiency was improved in beta-agonist fed steers 18 to 25% and hot carcass weight was increased by 1.8 to 3.7% (P < 0.05). Beta-agonists increased saleable yield by 0.6 to 1.9%, decreased fat by 0.6 to 1.3% and shifted tissue distribution such that a greater percentage of side weight was comprised of the muscles of the round (P < 0.05). Changes in development were observed as a result of beta-agonist use, specifically as an increased proportion of weight comprised of muscles of the hindquarter (P < 0.05). Use of beta-agonists negatively impacted shear force and sensory attributes. Beta-agonists had no effect on marbling; however, supplementation using any treatment increased shear force by 9 to 26%. Zilpaterol hydrochloride reduced trained panel ratings for tenderness, juiciness and flavor, but this was not observed in beef from steers treated with RH at 300 mg/hd/d. These effects were nearly linear as dose and potency of beta-agonists increased. The most aggressive beta-agonist treatments increased incidence of samples failing to be certified as tender from just over 10% in controls to approximately 20 to 25% at 21 d postmortem (P < 0.05). To produce beef comparable to current tenderness levels at retail, producers must appropriately manage use of beta-agonists and implants in populations of calf-fed Holstein steers

Recreating Beowulf’s “Pregnant Moment of Poise”: Pagan Doom and Christian Eucatastrophe Made Incarnate in the Dark Age Setting of The Lord of the Rings

In The Lord of the Rings, Tolkien recreates the “pregnant moment of poise” that inspired him in his study of Beowulf. Tolkien believed that this moment was a brief period of “fusion” which occurred in the Dark Ages as paganism was in decline and Christianity on the rise, when the dueling notions of Doom and salvation briefly coexisted in the hearts and minds of the Anglo-Saxon people. Derived from a careful study of Tolkien’s fiction, lectures, letters, and the writings of his contemporaries, instructors, and friends, in combination with many Dark Age texts, the works of various Tolkien critics, historians, and specialists in the fields of Christian and Norse apocalypse, this thesis will consider the ways that Tolkien’s study of Beowulf inspired him in the creation of The Lord of the Rings. Following the template that he outlined in his lecture, Tolkien integrated history, Christianity, and pagan myth to create a literary epic steeped in Christian and Norse apocalyptic images, in which incarnate religious figures walk abroad in a past that reflects the era in which Beowulf was set. The recreation of the “pregnant moment of poise” in this setting allows Tolkien to simultaneously enact the paradoxical outcomes of pagan Doom and Christian salvation at the novel’s climatic moments. When Doom and salvation collide, Tolkien’s heroes become martyrs without the necessity of death. Because they are mortals faced by powerfully magical enemies and are bereft of hope in victory, they are endowed with all of the rhetorical power that Doom elicits, but their miraculous deliverance enacts divine eucatastrophe, the moment of supreme joy that, to Tolkien, can only be fully appreciated when Doom gives birth to salvation