A Note on Real Tunneling Geometries

In the Hartle-Hawking ``no boundary'' approach to quantum cosmology, a real tunneling geometry is a configuration that represents a transition from a compact Riemannian spacetime to a Lorentzian universe. I complete an earlier proof that in three spacetime dimensions, such a transition is ``probable,'' in the sense that the required Riemannian geometry yields a genuine maximum of the semiclassical wave function.Comment: 5 page

International photovoltaic program. Volume 2: Appendices

The results of analyses conducted in preparation of an international photovoltaic marketing plan are summarized. Included are compilations of relevant statutes and existing Federal programs; strategies designed to expand the use of photovoltaics abroad; information on the domestic photovoltaic plan and its impact on the proposed international plan; perspectives on foreign competition; industry views on the international photovoltaic market and ideas about the how US government actions could affect this market;international financing issues; and information on issues affecting foreign policy and developing countries

Mean Curvature Flow on Ricci Solitons

We study monotonic quantities in the context of combined geometric flows. In particular, focusing on Ricci solitons as the ambient space, we consider solutions of the heat type equation integrated over embedded submanifolds evolving by mean curvature flow and we study their monotonicity properties. This is part of an ongoing project with Magni and Mantegazzawhich will treat the case of non-solitonic backgrounds \cite{a_14}.Comment: 19 page

Construction of two whole genome radiation hybrid panels for dromedary (Camelus dromedarius): 5000RAD and 15000RAD

The availability of genomic resources including linkage information for camelids has been very limited. Here, we describe the construction of a set of two radiation hybrid (RH) panels (5000RAD and 15000RAD) for the dromedary (Camelus dromedarius) as a permanent genetic resource for camel genome researchers worldwide. For the 5000RAD panel, a total of 245 female camel-hamster radiation hybrid clones were collected, of which 186 were screened with 44 custom designed marker loci distributed throughout camel genome. The overall mean retention frequency (RF) of the final set of 93 hybrids was 47.7%. For the 15000RAD panel, 238 male dromedary-hamster radiation hybrid clones were collected, of which 93 were tested using 44 PCR markers. The final set of 90 clones had a mean RF of 39.9%. This 15000RAD panel is an important high-resolution complement to the main 5000RAD panel and an indispensable tool for resolving complex genomic regions. This valuable genetic resource of dromedary RH panels is expected to be instrumental for constructing a high resolution camel genome map. Construction of the set of RH panels is essential step toward chromosome level reference quality genome assembly that is critical for advancing camelid genomics and the development of custom genomic tools

The Simplicial Ricci Tensor

The Ricci tensor (Ric) is fundamental to Einstein's geometric theory of gravitation. The 3-dimensional Ric of a spacelike surface vanishes at the moment of time symmetry for vacuum spacetimes. The 4-dimensional Ric is the Einstein tensor for such spacetimes. More recently the Ric was used by Hamilton to define a non-linear, diffusive Ricci flow (RF) that was fundamental to Perelman's proof of the Poincare conjecture. Analytic applications of RF can be found in many fields including general relativity and mathematics. Numerically it has been applied broadly to communication networks, medical physics, computer design and more. In this paper, we use Regge calculus (RC) to provide the first geometric discretization of the Ric. This result is fundamental for higher-dimensional generalizations of discrete RF. We construct this tensor on both the simplicial lattice and its dual and prove their equivalence. We show that the Ric is an edge-based weighted average of deficit divided by an edge-based weighted average of dual area -- an expression similar to the vertex-based weighted average of the scalar curvature reported recently. We use this Ric in a third and independent geometric derivation of the RC Einstein tensor in arbitrary dimension.Comment: 19 pages, 2 figure

Constructed Images of Iguazú National Park (Argentina) Related to Visitors’ Origins

We analyzed the perceptions of tourists visiting the famous waterfalls in Iguazú National Park to define how they envisaged the park with their constructed images. Nine hundred and seventy six questionnaires were completed by personally interviewing visitors in February and April 2011. They were asked to describe the park by choosing between 17 fixed features (tranquility, grandiosity, water, harmony, beauty, horizon, sound of nature, colors, rainforest, extension, green, maintenance, animals, diversity, nature, peace and wilderness) and also an open option. The constructed images were classified in categories of Beauty, Sublime, Picturesque and Spiritual and explored with SPSS and multivariate analyses. Results showed that the appeal of the waterfalls is multidimensional, combining different elements of the Picturesque, Sublime, Beauty, and also Spiritual, categories in different proportions. We identified associations between visitors’ origins and the constructed images among groups of visitors from North America, Latin-America, Europe, Australia, South Africa and East Asia. We confirmed the widespread election of picturesque and sublime features as visions with which to describe the national park. Water, beauty and grandiosity were the main features mentioned. Peace, tranquility and horizon were found as possible explanations for the divergence in visions between the six groups studied, especially segregating East Asians and South Africans from the other groups. The observed similarities and differences in the constructed images of Iguazú National Park of visitors coming from different parts of the world could be explained by both evolutionary and cultural frameworks. Some recommendations for park management and city planning are given

Secretion of Food Allergen Proteins in Saliva

RATIONALE: Peanut proteins were found to be secreted in 50% of lactating women’s breast milk. We wanted to develop a testing method to predict the secretion of peanut protein in breast milk. The secretion of food protein in saliva was hypothesized to be a possible predictor of secretion of foods in breast milk following ingestion. METHODS: Non-allergic volunteers, some lactating, ingested 50 grams of either whole peanuts, peanut milk or cow’s milk and various immunoassays were utilized to analyze for the presence of peanut or cow’s milk proteins in saliva and breast milk. Saliva and breast milk samples were subjected to SDS-PAGE, Western blot and ELISA analysis with anti-raw and roasted peanut and anti-alpha-casein antibodies and pooled serum IgE from peanut allergic individuals. RESULTS: Peanut protein levels in breast milk were undetectable using Western blot analysis and inconsistent with ELISA analysis. However, peanut proteins around 20 and 30 kDa that reacted with anti-roasted peanut antibody were detected, 6-18 hours following ingestion, in saliva of different individuals. An 18 KDa band that reacts with anti-alpha casein antibody was also detected in saliva 6-18 hours following ingestion. CONCLUSIONS: Secretion of food allergen proteins or peptides in saliva several hours following ingestion may have important implications for delayed allergic reaction by sensitive patients. Also, due to the fact that these proteins or peptides survive digestive enzymes, become absorbed into the blood stream and are subsequently secreted in biological fluids may indicate that they are most likely the sensitizing or tolerizing agent within an allergic food. Funding: National Peanut Board, USD

Triiodothyronine Represses MUC5AC Expression by Antagonizing Sp1 Binding to Its Promoter in Human Bronchial Epithelial HBE16 Cells

Mucus hypersecretion is a distinguished feature of chronic inflammatory airway diseases. Interestingly, in this condition thyroid function is impaired with decreased level of triiodothyronine (T3), indicating potential link between low level of T3 and mucus hypersecretion. But the underlying mechanisms are poorly understood. In this study we aimed to elucidate the effect of T3 on MUC5AC secretion in human bronchial epithelial HBE16 cells and further investigate how T3 regulates MUC5AC gene expression at transcriptional level. By RT-PCR and ELISA we showed that T3 inhibited MUC5AC mRNA expression and protein secretion in HBE16 cells. Furthermore, luciferase assay and site-directed mutagenesis analysis demonstrated that T3 repressed MUC5AC expression at transcriptional level and the mechanism might partly lie in the specific inhibition of Sp1 binding to the promoter. Our results suggest that decreased T3 level leads to the release of repression of MUC5AC expression and thus contributes to mucus hypersecretion

Nitrogen isotopes in chlorophyll and the origin of Eastern Mediterranean sapropels

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1997.Includes bibliographical references (p. 248-265).by Julian P. Sachs.Ph.D

Investigating Off-shell Stability of Anti-de Sitter Space in String Theory

We propose an investigation of stability of vacua in string theory by studying their stability with respect to a (suitable) world-sheet renormalization group (RG) flow. We prove geometric stability of (Euclidean) anti-de Sitter (AdS) space (i.e., $\mathbf{H}^n$) with respect to the simplest RG flow in closed string theory, the Ricci flow. AdS space is not a fixed point of Ricci flow. We therefore choose an appropriate flow for which it is a fixed point, prove a linear stability result for AdS space with respect to this flow, and then show this implies its geometric stability with respect to Ricci flow. The techniques used can be generalized to RG flows involving other fields. We also discuss tools from the mathematics of geometric flows that can be used to study stability of string vacua.Comment: 29 pages, references added in this version to appear in Classical and Quantum Gravit