T-Duality: Topology Change from H-flux

T-duality acts on circle bundles by exchanging the first Chern class with the fiberwise integral of the H-flux, as we motivate using E_8 and also using S-duality. We present known and new examples including NS5-branes, nilmanifolds, Lens spaces, both circle bundles over RP^n, and the AdS^5 x S^5 to AdS^5 x CP^2 x S^1 with background H-flux of Duff, Lu and Pope. When T-duality leads to M-theory on a non-spin manifold the gravitino partition function continues to exist due to the background flux, however the known quantization condition for G_4 fails. In a more general context, we use correspondence spaces to implement isomorphisms on the twisted K-theories and twisted cohomology theories and to study the corresponding Grothendieck-Riemann-Roch theorem. Interestingly, in the case of decomposable twists, both twisted theories admit fusion products and so are naturally rings.Comment: 36 pages, latex2e, uses xypic package. Made only a few superficial changes in the manuscrip

Yang-Mills theory for bundle gerbes

Given a bundle gerbe with connection on an oriented Riemannian manifold of dimension at least equal to 3, we formulate and study the associated Yang-Mills equations. When the Riemannian manifold is compact and oriented, we prove the existence of instanton solutions to the equations and also determine the moduli space of instantons, thus giving a complete analysis in this case. We also discuss duality in this context.Comment: Latex2e, 7 pages, some typos corrected, to appear in J. Phys. A: Math. and Ge

Access and Attitudes to HPV Vaccination amongst Hard-To-Reach Populations in Kenya.

BACKGROUND: Sub-Saharan Africa bears the greatest burden of cervical cancer. Human papillomavirus (HPV) vaccination programmes to prevent the disease will need to reach vulnerable girls who may not be able access health and screening services in the future. We conducted formative research on facilitators and barriers to HPV vaccination and potential acceptability of a future HPV vaccination programme amongst girls living in hard-to-reach populations in Kenya. METHODS: Stakeholder interviews with Ministry of Health staff explored barriers to and support for the uptake of HPV vaccination. A situation assessment was conducted to assess community services in Maasai nomadic pastoralist communities in Kajiado County and in Korogocho informal settlement in Nairobi city, followed by focus group discussions (n=14) and semi-structured interviews (n=28) with health workers, parents, youth, and community and religious leaders. These covered marriage, knowledge of cervical cancer and HPV, factors that might inhibit or support HPV vaccine uptake and intention to accept HPV vaccine if a programme was in place. RESULTS: Reported challenges to an HPV vaccination programme included school absenteeism and drop-out, early age of sex and marriage, lack of parental support, population mobility and distance from services. Despite little prior knowledge of cervical cancer and HPV, communities were interested in receiving HPV vaccination. Adequate social mobilisation and school-based vaccination, supplemented by out-reach activities, were considered important facilitating factors to achieve high coverage. There was some support for a campaign approach to vaccine delivery. CONCLUSIONS: Given the high level of support for a vaccine against cervical cancer and the experience of reaching pastoralist and slum-dwellers for other immunizations, implementing an HPV vaccine programme should be feasible in such hard-to-reach communities. This may require additional delivery strategies in addition to the standard school-based delivery, with vaccine offered at multiple venues, potentially through a campaign approach

The United Nations Basic Space Science Initiative: The TRIPOD concept

Since 1990, the United Nations is annually holding a workshop on basic space science for the benefit of the worldwide development of astronomy. Additional to the scientific benefits of the workshops and the strengthening of international cooperation, the workshops lead to the establishment of astronomical telescope facilities through the Official Development Assistance (ODA) of Japan. Teaching material, hands-on astrophysics material, and variable star observing programmes had been developed for the operation of such astronomical telescope facilities in an university environment. This approach to astronomical telescope facility, observing programme, and teaching astronomy has become known as the basic space science TRIPOD concept. Currently, a similar TRIPOD concept is being developed for the International Heliophysical Year 2007, consisting of an instrument array, data taking and analysis, and teaching space science.Comment: 8 pages, LaTe

S100 Inhibitors: A New Paradigm for Treating Alzheimer’s Disease

Alzheimer’s disease (AD) is the most common form of dementia, a neurological condition characterized by cognitive impairment and the inability to perform daily tasks. Neuritic protein aggregates in the brain, known as plaques, are a hallmark of AD pathology. These plaques are deposits of the amyloid-beta (A-Beta) peptide, which is derived from a larger molecule known as the amyloid precursor protein (APP). APP can be processed in one of two ways: in the non-amyloidogenic pathway, APP cleavage generates a variety of fragments that are thought to promote neuronal growth and survival; in the amyloidogenic pathway, APP cleavage leads to the production of the neurotoxic A-Beta peptide. Our lab has recently demonstrated that inhibition of two members of the S100 family of calcium binding proteins, S100A1 and S100B, synergistically reverses cognitive decline in the PSAPP mouse model of AD. However, the molecular underpinnings of this process are not known. This study tests the hypothesis that improved cognition, which is accompanied by a reduction in plaque load, is due to increased non-amyloidogenic APP processing. Western blotting was used to quantify the levels of full-length APP and A-Beta in brain lysates from 12-14 month old PSAPP and PSAPP/S100 knockout mice. APP and Aβ levels were similar in PSAPP/S100 knockout and PSAPP mice. These data suggest that the decreased pathology observed in SAPP/S100 knockout mice is not attributable to alternative processing of APP. Future directions of study include an examination of other possible mechanisms that may be responsible for observed differences in pathology. The molecular processes of plaque buildup and Aβ clearance have been proposed as targets for further study in S100 knockout mice. Once identified, this mechanistic information can be used toward the development of S100 inhibitors that improve memory loss in patients. The availability of novel pharmacological interventions for AD will significantly reduce the monetary and societal impacts of this debilitating disease

Topological Field Theory and Rational Curves

We analyze the superstring propagating on a Calabi-Yau threefold. This theory naturally leads to the consideration of Witten's topological non-linear sigma-model and the structure of rational curves on the Calabi-Yau manifold. We study in detail the case of the world-sheet of the string being mapped to a multiple cover of an isolated rational curve and we show that a natural compactification of the moduli space of such a multiple cover leads to a formula in agreement with a conjecture by Candelas, de la Ossa, Green and Parkes.Comment: 20 page

Robust free space board-to-board optical interconnect with closed loop MEMS tracking

We present a free-space optical interconnect system capable of dynamic closed-loop optical alignment using a microlens scanner with a proportional integral and derivative controller. Electrostatic microlens scanners based on combdrive actuators are designed and characterized with vertical cavity surface emitting lasers (VCSELs) for adaptive optical beam tracking in the midst of mechanical vibration noise. The microlens scanners are fabricated on silicon-on-insulator wafers with a bulk micromachining process using deep reactive ion etching. We demonstrate dynamic optical beam positioning with a 700 Hz bandwidth and a maximum noise reduction of approximately 40 dB. Eye diagrams with a 1 Gb/s modulation rate are presented to demonstrate the improved optical link in the presence of mechanical noise

Green Team – Ecological Restoration of Plaster Creek

Plaster Creek, though its watershed is home to many potential stewards in Grand Rapids, is the most polluted creek in West Michigan. The Green Team, a branch of Plaster Creek Stewards, is a group of students that work during the summer with a focus on research, education, and working directly to restore Plaster Creek. The team works toward this goal through urban green infrastructure, utilizing native plants to manage stormwater. Two Calvin students, Caleb Mathai and Jia Luchs, one high school intern, Ben Zwart, and twelve high school students living in the Plaster Creek watershed were hired by PCS this summer to work and learn together. The group was mentored by Rachel Warners, a recent Calvin College graduate. Nearby in Rockford, another Green Team for the Rogue River worked to maintain their watershed and joined the Plaster Creek team occasionally for projects

Stillbirths: ending preventable deaths by 2030

Efforts to achieve the new worldwide goals for maternal and child survival will also prevent stillbirth and improve health and developmental outcomes. However, the number of annual stillbirths remains unchanged since 2011 and is unacceptably high: an estimated 2·6 million in 2015. Failure to consistently include global targets or indicators for stillbirth in post-2015 initiatives shows that stillbirths are hidden in the worldwide agenda. This Series paper summarises findings from previous papers in this Series, presents new analyses, and proposes specific criteria for successful integration of stillbirths into post-2015 initiatives for women’s and children’s health. Five priority areas to change the stillbirth trend include intentional leadership; increased voice, especially of women; implementation of integrated interventions with commensurate investment; indicators to measure effect of interventions and especially to monitor progress; and investigation into crucial knowledge gaps. The post-2015 agenda represents opportunities for all stakeholders to act together to end all preventable deaths, including stillbirths