Shared Feed as a Means of Deer-to-Deer Transmission of Mycobacterium bovis

To determine the ability of experimentally inoculated white-tailed deer (Odocoileus virginianus) to transmit Mycobacterium bovis to naive deer through the sharing of feed, four deer were intratonsillarly inoculated with 4x105 colony-forming units of M. bovis. On a daily basis, feed not consumed by inoculated deer after approximately 8 hr was offered to four naıve deer maintained in a separate pen, where direct contact, aerosol transmission, or transmission through personnel were prevented. After 150 days, naıve deer were euthanized and examined. All naıve deer had lesions consistent with tuberculosis and M. bovis was isolated from various tissues. The most commonly affected tissues were lung, tracheobronchial lymph nodes, and mediastinal lymph nodes. This study demonstrates the potential for indirect transmission of M. bovis through the sharing of feed. Intentional or unintentional feeding of deer by wildlife or agricultural interests in regions where M. bovis infection is endemic should be avoided because both direct and indirect transmission through sharing of feed are enhanced.

American Lives: A Reader [Preface & Introduction]

Memoirs are as varied as human emotion and experience, and those published in the distinguished American Lives Series run the gamut. Excerpted from this series (called “splendid” by Newsweek) and collected here for the first time, these dispatches from American lives take us from China during the Cultural Revolution to the streets of New York in the sixties to a cabin in the backwoods of Idaho. In prose as diverse as the stories they tell, writers such as Floyd Skloot, Ted Kooser, Peggy Shumaker, and Lee Martin, among many others, open windows to their own ordinary and extraordinary experiences. John Skoyles tells how, for his Uncle Fred, a particular “Hard Luck Suit” imparted misfortune. Brenda Serotte describes a Turkish grandmother who made her living reading palms, interpreting cups, and prescribing poultices for the community. In “Son of Mr. Green Jeans,” Dinty W. Moore views fatherhood through the lens of pop culture. Janet Sternburg’s Phantom Limb muses on the dilemmas of a child caring for a parent. Whether evoking moments of death or disease, in family or marriage, history, politics, religion, or culture, these glimpses into singular American lives come together in a richly textured, colorful patchwork quilt of American life.

Survivable Lightpath Provisioning in WDM Mesh Networks Under Shared Path Protection and Signal Quality Constraints

This paper addresses the problem of survivable lightpath provisioning in wavelength-division-multiplexing (WDM) mesh networks, taking into consideration optical-layer protection and some realistic optical signal quality constraints. The investigated networks use sparsely placed optical–electrical–optical (O/E/O) modules for regeneration and wavelength conversion. Given a fixed network topology with a number of sparsely placed O/E/O modules and a set of connection requests, a pair of link-disjoint lightpaths is established for each connection. Due to physical impairments and wavelength continuity, both the working and protection lightpaths need to be regenerated at some intermediate nodes to overcome signal quality degradation and wavelength contention. In the present paper, resource-efficient provisioning solutions are achieved with the objective of maximizing resource sharing. The authors propose a resource-sharing scheme that supports three kinds of resource-sharing scenarios, including a conventional wavelength-link sharing scenario, which shares wavelength links between protection lightpaths, and two new scenarios, which share O/E/O modules between protection lightpaths and between working and protection lightpaths. An integer linear programming (ILP)-based solution approach is used to find optimal solutions. The authors also propose a local optimization heuristic approach and a tabu search heuristic approach to solve this problem for real-world, large mesh networks. Numerical results show that our solution approaches work well under a variety of network settings and achieves a high level of resource-sharing rates (over 60% for O/E/O modules and over 30% for wavelength links), which translate into great savings in network costs.

A Load-Balancing Shared-Protection-Path Reconfiguration Approach in WDM Wavelength-Routed Networks

Wavelength-routed networks (WRN) are very promising candidates for next-generation Internet and telecommunication backbones. In such a network, optical-layer protection is of paramount importance due to the risk of losing large amounts of data under a failure. To protect the network against this risk, service providers usually provide a pair of risk-independent working and protection paths for each optical connection. However, the investment made for the optical-layer protection increases network cost. To reduce the capital expenditure, service providers need to efficiently utilize their network resources. Among all the existing approaches, shared-path protection has proven to be practical and cost-efficient [1]. In shared-path protection, several protection paths can share a wavelength on a fiber link if their working paths are risk-independent. In real-world networks, provisioning is usually implemented without the knowledge of future network resource utilization status. As the network changes with the addition and deletion of connections, the network utilization will become sub-optimal. Reconfiguration, which is referred to as the method of re-provisioning the existing connections, is an attractive solution to fill in the gap between the current network utilization and its optimal value [2]. In this paper, we propose a new shared-protection-path reconfiguration approach. Unlike some of previous reconfiguration approaches that alter the working paths, our approach only changes protection paths, and hence does not interfere with the ongoing services on the working paths, and is therefore risk-free. Previous studies have verified the benefits arising from the reconfiguration of existing connections [2] [3] [4]. Most of them are aimed at minimizing the total used wavelength-links or ports. However, this objective does not directly relate to cost saving because minimizing the total network resource consumption does not necessarily maximize the capability of accommodating future connections. As a result, service providers may still need to pay for early network upgrades. Alternatively, our proposed shared-protection-path reconfiguration approach is based on a load-balancing objective, which minimizes the network load distribution vector (LDV, see Section 2). This new objective is designed to postpone network upgrades, thus bringing extra cost savings to service providers. In other words, by using the new objective, service providers can establish as many connections as possible before network upgrades, resulting in increased revenue. We develop a heuristic load-balancing (LB) reconfiguration approach based on this new objective and compare its performance with an approach previously introduced in [2] and [4], whose objective is minimizing the total network resource consumption.

A Heuristic with Bounded Guarantee to Compute Diverse Paths under Shared Protection in WDM Mesh Networks

Establishing a fault-tolerant connection in a network involves computation of diverse working and protection paths. The Shared Risk Link Group (SRLG) [1] concept is used to model several types of failure conditions such as link, node, fiber conduit, etc. In this work we focus on the problem of computing optimal SRLG/link diverse paths under shared protection. Shared protection technique improves network resource utilization by allowing protection paths of multiple connections to share resources. In this work we propose an iterative heuristic for computing SRLG/link diverse paths. We present a method to calculate a quantitative measure that provides a bounded guarantee on the optimality of the diverse paths computed by the heuristic. The experimental results on computing link diverse paths show that our proposed heuristic is efficient in terms of number of iterations required (time taken) to compute diverse paths when compared to other previously proposed heuristics.

Survivable Virtual Topology Routing under Shared Risk Link Groups in WDM Networks

Network survivability is one of the most important issues in the design of optical WDM networks. In this work we study the problem of survivable routing of a virtual topology on a physical topology with Shared Risk Link Groups (SRLG). The survivable virtual topology routing problem against single-link failures in the physical topology is proved to be NP-complete in [1]. We prove that survivable virtual topology routing problem against SRLG/node failures is also NP-complete. We present an improved integer linear programming (ILP) formulation (in comparison to [1]) for computing the survivable routing under SRLG/node failures. Using an ILP solver, we computed the survivable virtual topology routing against link and SRLG failures for small and medium sized networks efficiently. As even our improved ILP formulation becomes intractable for large networks, we present a congestion-based heuristic and a tabu search heuristic (which uses the congestion-based heuristic solution as the initial solution) for computing survivable routing of a virtual topology. Our experimental results show that tabu search heuristic coupled with the congestion based heuristic (used as initial solution) provides fast and near-optimal solutions.

Portraits of Protestant Teens: A Report on Teenagers in Major U.S. Denominations

This report examines the religious beliefs and practices of American Protestant teenagers using new, nationally representative survey data from the National Study of Youth and Religion (NSYR). The NSYR is a major study of the religious and spiritual lives of contemporary American teens, which recently produced a book on its major findings entitled, Soul Searching: the Religious and Spiritual Lives of American Teenagers (by Christian Smith with Melinda Lundquist Denton, Oxford University Press, 2005). In addition to broadly describing the religious outlook of Protestant teenagers today — and as a more detailed, descriptive follow-up to that book — this report highlights several positive and negative experiences and evaluations of teenagers in different Protestant denominations and groupings of denominations. In brief, this report presents the following findings in these areas of interest: ♦ Religious Participation: Protestant teenagers are relatively active in religious organizations and activities, both within and beyond their churches. About one-half of all Protestant teens attend church weekly, participate in Sunday school or in a religious youth group, pray and attend a religious summer camp or retreat, though less than one-third read the Bible each week. This also means, however, that substantial numbers of Protestant teens are not actively participating in their religious traditions. Teens from conservative denominations such as Southern Baptist Convention and Assemblies of God are especially likely to regularly attend church and participate in other religious activities. ♦ Theological Beliefs: Protestant teenagers are likely to hold many traditional Christian religious beliefs. The majority of Protestant teens say they believe in God, the afterlife, angels, demons, miracles, judgment day and they view God as a personal being involved in the lives of people today. Sizable numbers of Protestant teens, on the other hand, do not hold these traditional Christian religious beliefs. Teens from conservative and black Protestant denominations are more likely than mainline Protestant teens to hold these religious beliefs. ♦ Importance of Faith: The majority of Protestant teenagers report that their religious faith is very important in their lives. Most of them also say that their families talk about religion together, that they have shared their faith with someone not of their faith and that they have had a powerful worship experience. A large minority of all Protestant teenagers, and in the case of some denominations a majority of teenagers, do not report that religious faith is very important in their lives. Teens from conservative and black Protestant denominations are particularly likely to report that faith is important in their lives. ♦ Evaluations of Churches: The majority of Protestant teenagers express relatively positive views of their churches and fellow church members. They typically report that they would continue to attend church if it were totally up to them, that they would attend a similar church if given the choice and that their current church is generally warm and welcoming. Protestant adolescents, however, do have some reservations about and problems with their churches and fellow church attendees, as spelled out in the following pages, particularly with other teenage attendees.

IMMIGRATION, THE AMERICAN WEST, AND THE TWENTIETH CENTURY: GERMAN FROM RUSSIA, OMAHA INDIAN, AND VIETNAMESE-URBAN VILLAGERS IN LINCOLN, NEBRASKA

The North American West is a culturally and geographically diverse region that has long been a beacon for successive waves of human immigration and migration. A case in point, the population of Lincoln, Nebraska -- a capital city on the eastern cusp of the Great Plains -- was augmented during the twentieth century by significant influxes of Germans from Russia, Omaha Indians, and Vietnamese. Arriving in clusters beginning in 1876, 1941, and 1975 respectively, these newcomers were generally set in motion by dismal economic, social, or political situations in their sending nations. Seeking better lives, they entered a mainstream milieu dominated by native-born Americans -- most part of a lateral migration from Iowa, Illinois, and Pennsylvania -- who only established their local community in 1867. While this mainstream welcomed their labor, it often eschewed the behaviors and cultural practices ethnic peoples brought with them. Aware but not overly concerned about these prejudices, all three groups constructed or organized distinct urban villages. The physical forms of these enclaves ranged from homogeneous neighborhoods to tight assemblies of relatives, but each suited a shared preference for living among kinspeople. These urban villages also served as stable anchors for unique peoples who were intent on maintaining aspects of their imported cultural identities. Never willing to assimilate to mainstream norms, urban villagers began adapting to their new milieus. While ethnic identity constructions in Lincoln proved remarkably enduring, they were also amazingly flexible. In fact, each subject group constantly negotiated their identities in response to interactions among particular, cosmopolitan, and transnational forces. Particularism refers largely to the beliefs, behaviors, and organizational patterns urban villagers imported from their old milieus. Cosmopolitan influences emanated from outside the ethnic groups and were dictated largely but not exclusively by the mainstream. Transnationalism is best defined as persistent, intense contact across international boundaries. These influences were important as the particularism of dispersed peoples was often reinforced by contact with sending cultures. Adviser: John. R. Wunder