The Impact of Foregrounds on Redshift Space Distortion Measurements With the Highly-Redshifted 21 cm Line

The highly redshifted 21 cm line of neutral hydrogen has become recognized as a unique probe of cosmology from relatively low redshifts (z ~ 1) up through the Epoch of Reionization (z ~ 8) and even beyond. To date, most work has focused on recovering the spherically averaged power spectrum of the 21 cm signal, since this approach maximizes the signal-to-noise in the initial measurement. However, like galaxy surveys, the 21 cm signal is affected by redshift space distortions, and is inherently anisotropic between the line-of-sight and transverse directions. A measurement of this anisotropy can yield unique cosmological information, potentially even isolating the matter power spectrum from astrophysical effects. However, in interferometric measurements, foregrounds also have an anisotropic footprint between the line-of-sight and transverse directions: the so-called foreground "wedge". Although foreground subtraction techniques are actively being developed, a "foreground avoidance" approach of simply ignoring contaminated modes has arguably proven most successful to date. In this work, we analyze the effect of this foreground anisotropy in recovering the redshift space distortion signature in 21 cm measurements at both high and intermediate redshifts. We find the foreground wedge corrupts nearly all of the redshift space signal for even the largest proposed EoR experiments (HERA and the SKA), making cosmological information unrecoverable without foreground subtraction. The situation is somewhat improved at lower redshifts, where the redshift-dependent mapping from observed coordinates to cosmological coordinates significantly reduces the size of the wedge. Using only foreground avoidance, we find that a large experiment like CHIME can place non-trivial constraints on cosmological parameters.Comment: 9 pages, 5 figures, 4 tables; minor changes to match version accepted by MNRA

Serial Cultivation of Single Keratinocytes from the Outer Root Sheath of Human Scalp Hair Follicles

A method for the isolation of outer root sheath keratinocytes from plucked human hair follicles and for their subsequent cultivation has been developed. The selective trypsinization of outer root sheath keratinocytes provided a single cell suspension of defined origin within the hair follicle. The 3T3 feeder layer technique supports sustained growth of these cells in that as little as one single plucked hair follicle (yielding approximately 1.5 × 104 cells) consistently gave rise to a confluent 35-mm culture dish (with approximately 1.5 × 106 cells) within about 2 weeks. The outer root sheath keratinocytes can be serially passaged for up to 3 times and also cryopreserved

A Hard Real-Time Kernel for Motorola Microcontrollers

This paper describes a real-time kernel for running embedded applications on a recent family of Motorola microcontrollers. Both periodic and aperiodic real-time tasks are managed, as well as non real-time tasks. The kernel has been called Yartos, and uses a hard real-time scheduling algorithm based on an EDF approach for the periodic task; aperiodic tasks are executed with a Total Bandwith Server

Perceptions Of Undergraduate Business Students Toward Online Courses In Higher Education Expanded And Revisited: Do Gender, Age, And/Or Past Experiences Make A Difference?

This study analyzes the perceptions and preferences of a group of undergraduate business students with respect to taking on-line or distance education courses. In this last decade, distant learning programs have become very popular, and the number of offerings continues to increase.  The growing popularity of this medium for instruction is due to a combination of factors.  Technological advances have made the availability both economical and practical. The economic advantages of distributing scarce resources, geographically and temporally, to students in remote locations provide a broader market for distance education. Additionally, the increasing demand from students to acquire education at times that are convenient given their busy schedules and personal commitments makes distance education attractive to working learners (Roberts 1998). The new opportunities distance learning has provided have enabled students to create an atmosphere for learning at home. The distance debate usually focuses on issues related to student learning and outcomes and student attitudes as compared to traditional classroom-based settings (Phillips, 1998; Webster & Hackley, 1997).  This study attempts to address these and other topics such as what is distance learning, what are the advantages and disadvantages, and what changes can be made to improve this type of learning.  This research is intended to give students a realistic expectation of what to anticipate from distance learning courses based on information we have found and studies we have done.  It is important that students have a realistic perception of the distant learning experience

A Comparison of Small and Large European Cities for Tourism: Implications for Strategic Marketing Communications

The purpose of this thesis is to compare major and minor European cities based on their marketing mixes and creating the best marketing communication strategies for small municipalities. The secondary research completed for this report was done by reviewing dossiers, professional reports, newspaper articles, and scholarly and government websites, on the subject of travel trends and reasons to travel abroad. Next small and large cities were compared based on their price, product, place and promotion, which also included case studies comparing different sized cities from the same country to each other. A SWOT analysis was also conducted on the three smaller cities from the case studies and the target markets for the marketing communication strategies were defined. Primary research was conducted by interviewing and surveying couples who were part of the selected target market. Lastly, there were three marketing campaigns created for three separate cities with two target audiences. Through this research it was found couples want to visit safe locations, the city’s character, and beautiful views. American couples were influenced the most by friends and family as well as travel discounts when choosing where to visit. The conclusion from this thesis is American couples prefer the uniqueness of smaller cities, but they also take other factors such as safety and the general feel of the location into consideration when booking a vacation flight. It is important for cities to use this knowledge to their advantage and create a resonating brand image which entices couples to travel there. Hence, three comprehensive marketing communication strategies were developed to aid small cities in accomplishing this goal

Have Basic Mathematical Skills Grown Obsolete In The Computer Age: Assessing Basic Mathematical Skills And Forecasting Performance In A Business Statistics Course

The purpose of this study was to measure the comprehension of basic mathematical skills of  students enrolled in statistics classes at a large regional university, and to determine if the scores earned on a basic math skills test are useful in forecasting student performance in these statistics classes, and to determine if students’ basic math skills have changed over time. The results showed that 22 percent of the students’ final grades in business statistics courses were explained by their scores on this skills test.  These findings may be of use to statistics faculty in identifying students who experience difficulties in these courses in the future.  The current students’ scores were compared to scores from a test previously given to students in 1992/1993.  The students from the first group had significantly higher scores than the current group of students.&nbsp

Interview with BJ Noser Ingram on the History of the Land Used in South McAllen

An interview with a RGV community member that explores her experience in the border region. Conducted by a school teacher participating in the Porciones to Colonias project. B.J. Noser Ingram – Interviewee Claudia Tijerina – Interviewer Eloise Montemayor – Videographerhttps://scholarworks.utrgv.edu/chapsoralhistories/1110/thumbnail.jp

The Online Classroom: Differences In Perception Between Business Students And Non-Business Students

The authors discuss the results of a questionnaire given to 893 undergraduate college students regarding distance-learning courses, which reveal a number of differences in perception between business and non-business students.  The authors suggest possible reasons for these differences, and make recommendations to university administrators and faculty as to what could be done to help reduce or limit these differences.  The results of this study should be of interest to university administrators, faculty members, and students who plan to offer, teach, or take online courses in the future.  In addition, this information may be helpful to university administrators in deciding which types of courses at their universities might be offered online.  Faculty who are considering teaching one or more online courses may find the results of this study helpful in structuring these online offerings.  This research is intended to give students a realistic expectation of what to anticipate from distance learning courses based on information we have found and studies we have done