Path Selection for Quantum Repeater Networks

Quantum networks will support long-distance quantum key distribution (QKD) and distributed quantum computation, and are an active area of both experimental and theoretical research. Here, we present an analysis of topologically complex networks of quantum repeaters composed of heterogeneous links. Quantum networks have fundamental behavioral differences from classical networks; the delicacy of quantum states makes a practical path selection algorithm imperative, but classical notions of resource utilization are not directly applicable, rendering known path selection mechanisms inadequate. To adapt Dijkstra's algorithm for quantum repeater networks that generate entangled Bell pairs, we quantify the key differences and define a link cost metric, seconds per Bell pair of a particular fidelity, where a single Bell pair is the resource consumed to perform one quantum teleportation. Simulations that include both the physical interactions and the extensive classical messaging confirm that Dijkstra's algorithm works well in a quantum context. Simulating about three hundred heterogeneous paths, comparing our path cost and the total work along the path gives a coefficient of determination of 0.88 or better.Comment: 12 pages, 8 figure

An advertising aesthetic: Real beauty and visual impairment

This article considers critical responses to disability in 20th-century Anglo-American advertisements from which a problematic advertising aesthetic emerges. The aesthetic is used to test the progressiveness of a recent trilogy of Dove advertisements that represents visual impairment. The conclusion is that while there has been much progress, the ableist advertising aesthetic of decades ago remains an issue in the 21st century. More specifically, the Dove advertisements are found to be underpinned by ocularcentrism, despite their apparent appreciation of visual impairment

The functional, social and economic impact of acute encephalitis syndrome in Nepal--a longitudinal follow-up study.

notes: PMCID: PMC3772013Open Access JournalOver 133,000 children present to hospitals with Acute Encephalitis Syndrome (AES) annually in Asia. Japanese encephalitis (JE) accounts for approximately one-quarter of cases; in most cases no pathogen is identified and management is supportive. Although JE is known to result in neurological impairment, few studies have examined the wider impact of JE and AES on patients and their families.Wellcome TrustUniversity of Liverpool Clinical Fellowshi

Can managers empower nurse-midwives to improve maternal health care? A comparison of two resource-poor hospitals in Tanzania

Maternal mortality is very high in Tanzania. Competent hospital care is key to improving maternal outcomes, but there is a crisis of availability and performance of health workers in maternal care. This article uses interviews with managers, nurse-midwives, and women who had given birth in two hospitals providing virtually all the emergency maternal care in one Tanzania city. It contrasts women's experience in the two hospitals, and analyses interconnections with nurse-midwives' and managers' experiences of working conditions. The conceptual literature on nurse empowerment identifies some key explanatory variables for these contrasts. Staff experienced less frustration and constraint in one of the hospitals; had more access to structurally empowering resources; and experienced greater congruence between job commitment and working culture, resulting in better work engagement. Conversely, nurse-midwives in the other hospital were constrained by supply shortages and recurrent lack of support. Contrasting management styles and their impacts demonstrate that even in severely resource-constrained environments, there is room for management to empower staff to improve maternal care. Empowering management practices include participatory management, supportive supervision, better incentives, and clear leadership concerning ward culture. Structural constraints beyond the capacity of health facility managers must however also be addresse

Application of handheld devices to field research among underserved construction worker populations: a workplace health assessment pilot study

This is the final version of the article. Available from BioMed Central via the DOI in this record.BACKGROUND: Novel low-cost approaches for conducting rapid health assessments and health promotion interventions among underserved worker groups are needed. Recruitment and participation of construction workers is particularly challenging due to their often transient periods of work at any one construction site, and their limited time during work to participate in such studies. In the present methodology report, we discuss the experience, advantages and disadvantages of using touch screen handheld devices for the collection of field data from a largely underserved worker population. METHODS: In March 2010, a workplace-centered pilot study to examine the feasibility of using a handheld personal device for the rapid health assessment of construction workers in two South Florida Construction sites was undertaken. A 45-item survey instrument, including health-related questions on tobacco exposure, workplace safety practices, musculoskeletal disorders and health symptoms, was programmed onto Apple iPod Touch® devices. Language sensitive (English and Spanish) recruitment scripts, verbal consent forms, and survey questions were all preloaded onto the handheld devices. The experience (time to survey administration and capital cost) of the handheld administration method was recorded and compared to approaches available in the extant literature. RESULTS: Construction workers were very receptive to the recruitment, interview and assessment processes conducted through the handheld devices. Some workers even welcomed the opportunity to complete the questionnaire themselves using the touch screen handheld device. A list of advantages and disadvantages emerged from this experience that may be useful in the rapid health assessment of underserved populations working in a variety of environmental and occupational health settings. CONCLUSIONS: Handheld devices, which are relatively inexpensive, minimize survey response error, and allow for easy storage of data. These technological research modalities are useful in the collection and assessment of environmental and occupational research data.This study was supported in part by the National Institute for Occupational Safety and Health (NIOSH)'s Deep South Educational Research Center at the University of Alabama (sub-contract: 288477-10) as a Graduate Student Pilot Grant Award; the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) grant F31AR057687 and the National Institute for Occupational Safety and Health (NIOSH) grant R01 OH003915