Ending Laminations and Cannon-Thurston Maps

In earlier work, we had shown that Cannon-Thurston maps exist for Kleinian surface groups. In this paper we prove that pre-images of points are precisely end-points of leaves of the ending lamination whenever the Cannon-Thurston map is not one-to-one. In particular, the Cannon-Thurston map is finite-to-one. This completes the proof of the conjectural picture of Cannon-Thurston maps for surface groups.Comment: v4: Final version 22pgs 2figures. Includes the main theorem of the appendix arXiv:1002.2090 by Shubhabrata Das and Mahan Mj. To appear in Geometric and Functional Analysi

Fairbanks Gang Assessment

The Justice Center at University of Alaska Anchorage partnered with the Fairbanks Gang Reduction and Intervention Network (GRAIN) to perform a thorough assessment of the gang problem in Fairbanks following the protocol outlined by the Office of Juvenile Justice and Delinquency Prevention (OJJDP)’s Comprehensive Gang Model. Law enforcement data show that there are at least 12 active gangs in the Fairbanks North Star Borough, with the percentage of crime reported to law enforcement attributable to gangs (2007-2009) varying from a low of 4.3% in 2007 to a high of 7.2% in 2008. The complete assessment, contained in this report, includes a review of community demographic data, law enforcement data, student and school data, and community perceptions data.Fairbanks Gang Reduction and Intervention Network Grant No. 2007-JV-FX-0331Index of Tables and Figures / Acknowledgements / Section I Fairbanks Gang Assessment: Executive Summary / Section II Fairbanks Gang Assessment: Community Demographic Data / Section III Fairbanks Gang Assessment: Law Enforcement Data / Section IV Fairbanks Gang Assessment: Student and School Data / Section V Fairbanks Gang Assessment: Community Perceptions Data / Section VI Fairbanks Gang Assessment: Community Resources Data / Section VII Fairbanks Gang Assessment Methods / References / Appendix A Community Resident Survey / Appendix B Student Survey / Appendix C Youth Serving and Law Enforcement Agency Survey / Appendix D Gang Member Interview For

The Impact of Information Technology on Motor Carrier Productivity

This study examines the relationship between motor carrier productivity, marketing strategy, and use of information technology for a sample of U.S. general freight commodity carriers. We use a unique data set containing information on firm marketing strategy and information technology use collected in a survey of Class I and II motor carrier firms (U.S. Department of Transportation, 1999). The measure of productivity used here is the non-parametric Malmquist Index as explained in Grosskopf (1993) and previously applied to general freight motor carriers by McMullen and Okuyama (2000). The Malmquist Index is decomposed into two components: economic efficiency change (EC) and technical efficiency change (TC). A tobit model regression model is used to examine the relationship between firm productivity, marketing strategy, and use of information technology. Information technologies included in the tobit analysis are electronic data interchange (EDI) and satellite communications (SATCOM). We also include firm size, use of owner-operators, and percent unionization as explanatory variables in the tobit regression. Results indicate that use of EDI has a positive and significant impact on economic efficiency (EC). Firms that try to market their product by providing service at the "lowest freight rate" are found to exhibit greater technical efficiency (TC), suggesting that productivity and cost measures that ignore marketing strategy may be biased. Finally, economic efficiency (EC) is found to be significantly greater for firms that are more heavily unionized

AN ANALYSIS OF THE USE OF GRADES AND HOUSEBRAND LABELS IN THE RETAIL BEEF MARKET

The congruence of beef consumersÂ’ purchases with their stated preferences regarding internal fat content are examined. The role of U.S. Department of Agriculture (USDA) grades and housebrand labeling of beef in providing information to consumers is studied in the theoretical framework of search theory. The empirical results indicate that the current system of USDA grades and housebrand labels is not disseminating information regarding internal fat content effectively to consumers. Suggestions are made for providing consumers with better information and education necessary to increase congruence of expressed preferences regarding internal fat content and actual beef purchases.Food Consumption/Nutrition/Food Safety, Livestock Production/Industries,

Head Start Sınıflarında Erken Okuma-Yazma Müfredatını Geliştirmeye Yönelik Bir Çalışma

Early childhood education studies draw attention to the importance of the early childhood years for future learning and development, and in particular, literacy development. Thus, early childhood programs, including Head Start, must be prepared and able to support children in their early language and literacy development by creating appropriate experiences and environments. In this study, the early literacy beliefs and practices of four Head Start teachers were examined using qualitative (interviews, early literacy quilt, and documents) method. The data supported a conclusion that a university-school partnership can impact literacy practices. Teachers who were provided with this teacher improvement program and ongoing support changed their practices from the beginning to the end of the study period. Particularly, the teachers seemed to improve their efforts to meet the early literacy needs of children which were the targeted goal of the study. Also, unlike most previous intervention studies, which resulted in change to a specific domain or created an impact on a limited behavior, the current improvement effort created more broad-based change. It impacted teachers’ beliefs about early literacy, how they arranged their classroom environments, as well their notions of the value of a research partnership with the university. Ensuring the high qualifications of teaching staff requires that early childhood programs, including Head Start, devote funding to ongoing professional development. Through such programs teachers can develop their knowledge and competence in supporting all children’s early literacy and language development.Erken çocukluk çalışmaları, erken yaşların gelecekteki gelişim ve öğrenme özellikle de erken okuma-yazma için önemine dikkat çekmektedir. Bu yüzden, okul öncesi eğitim programları Head Start dahil olmak üzere çocukların erken dil ve okuma-yazma gelişimlerini uygun ortamlar ve yaşantılar oluşturarak desteklemelidirler. Bu çalışmada, nitel yöntem kullanılarak dört Head Start program öğretmeninin erken okuma-yazmaya dair inanışları ve uygulamaları incelenmiştir. Veriler üniversite-okul işbirliğinin erken okuma-yazma uygulamalarını etkileyebileceği sonucunu desteklemiştir. Devamlı destek verilen ve geliştirme programı uygulanan öğretmenler, çalışmanın başından sonuna uygulamalarını değiştirmişlerdir. Özellikle, öğretmenler çalışmanın da temel amacı olan çocukların erken okuma-yazma ihtiyaçlarını karşılamaya yönelik çabalarını geliştirmişlerdir. Ayrıca, önceden yapılmış ve belirli bir alanda değişiklikle sonuçlanmış veya sınırlı bir davranış üzerinde etki yaratan birçok müdahale çalışmasının aksine, bu çalışma daha geniş çaplı bir değişim yaratmıştır. Çalışma, öğretmenlerin erken okuma-yazma hakkındaki inanışlarını, sınıf ortamlarını nasıl düzenlediklerini ve bir üniversite ile araştırma ortağı olmanın değeriyle ilgili görüşlerini değiştirmiştir. Eğitim personelinin yüksek kalitede olmasını sağlamak Head Start da dahil olmak üzere erken çocukluk eğitimi programlarının sürekli bir hizmetiçi eğitim için yeterli fonu ayırmalarını gerektirmektedir. Bu tür eğitim programları aracılığıyla öğretmenler çocukların erken okuma-yazma ve dil gelişimini destekleyecek bilgi ve yeterliliği geliştirebilirler

Determinants of VMT in Urban Areas:A Panel Study of 87 U.S. Urban Areas 1982-2009

This paper uses econometric techniques to examine the determinants of vehicle miles traveled (VMT) in a panel study using data from a cross section of 87 U.S. urban areas over the period 1982-2009. We use standard OLS regression as well as two-stage least squares techniques to examine the impact of factors such as urban density, lane-miles, per capita income, real fuel cost, transit mileage, and various industry mix variables on per capita VMT. We use a distributed lag model to estimate long-run elasticities and find that the long-run price elasticity of demand for per capita VMT is approximately five times larger than in the short run. Preliminary empirical results show the per capita demand for VMT in urban areas is positively and significantly impacted by lane miles, personal income, and the percent of employment in the construction and public sectors. Fuel price and transit use and the percent of employment in manufacturing, retail, and wholesale sectors are all found to be statistically significant and negatively related to VMT per capita. After correcting for endogeneity, urban population density exerts a negative, but not always statistically significant, impact on per capita VMT. Finally, per capita VMT is found to differ significantly by geographic region, being higher the more western and the larger the population size of an urban area

Organizing information on the next generation web - Design and implementation of a new bookmark structure

The next-generation Web will increase the need for a highly organized and ever evolving method to store references to Web objects. These requirements could be realized by the development of a new bookmark structure. This paper endeavors to identify the key requirements of such a bookmark, specifically in relation to Web documents, and sets out a suggested design through which these needs may be accomplished. A prototype developed offers such features as the sharing of bookmarks between users and groups of users. Bookmarks for Web documents in this prototype allow more specific information to be stored such as: URL, the document type, the document title, keywords, a summary, user annotations, date added, date last visited and date last modified. Individuals may access the service from anywhere on the Internet, as long as they have a Java-enabled Web browser

Rigidity and volume preserving deformation on degenerate simplices

Given a degenerate $(n+1)$-simplex in a $d$-dimensional space $M^d$ (Euclidean, spherical or hyperbolic space, and $d\geq n$), for each $k$, $1\leq k\leq n$, Radon's theorem induces a partition of the set of $k$-faces into two subsets. We prove that if the vertices of the simplex vary smoothly in $M^d$ for $d=n$, and the volumes of $k$-faces in one subset are constrained only to decrease while in the other subset only to increase, then any sufficiently small motion must preserve the volumes of all $k$-faces; and this property still holds in $M^d$ for $d\geq n+1$ if an invariant $c_{k-1}(\alpha^{k-1})$ of the degenerate simplex has the desired sign. This answers a question posed by the author, and the proof relies on an invariant $c_k(\omega)$ we discovered for any $k$-stress $\omega$ on a cell complex in $M^d$. We introduce a characteristic polynomial of the degenerate simplex by defining $f(x)=\sum_{i=0}^{n+1}(-1)^{i}c_i(\alpha^i)x^{n+1-i}$, and prove that the roots of $f(x)$ are real for the Euclidean case. Some evidence suggests the same conjecture for the hyperbolic case.Comment: 27 pages, 2 figures. To appear in Discrete & Computational Geometr

Accidental parabolics and relatively hyperbolic groups

By constructing, in the relative case, objects analoguous to Rips and Sela's canonical representatives, we prove that the set of images by morphisms without accidental parabolic, of a finitely presented group in a relatively hyperbolic group, is finite, up to conjugacy.Comment: Revision, 24 pages, 4 figure

Regular Incidence Complexes, Polytopes, and C-Groups

Regular incidence complexes are combinatorial incidence structures generalizing regular convex polytopes, regular complex polytopes, various types of incidence geometries, and many other highly symmetric objects. The special case of abstract regular polytopes has been well-studied. The paper describes the combinatorial structure of a regular incidence complex in terms of a system of distinguished generating subgroups of its automorphism group or a flag-transitive subgroup. Then the groups admitting a flag-transitive action on an incidence complex are characterized as generalized string C-groups. Further, extensions of regular incidence complexes are studied, and certain incidence complexes particularly close to abstract polytopes, called abstract polytope complexes, are investigated.Comment: 24 pages; to appear in "Discrete Geometry and Symmetry", M. Conder, A. Deza, and A. Ivic Weiss (eds), Springe