N=2 Coset Compactifications with Non-Diagonal Invariants

We consider 4-dimensional string models obtained by tensoring N=2 coset theories with non-diagonal modular invariants. We present results from a systematic analysis including moddings by discrete symmetries.Comment: 29 page

Cyclic Permutations in Kazama-Suzuki String Models

Moddings by cyclic permutation symmetries are performed in 4-dimensional strings, built up from N=2 coset models of the type $CP_m=SU(m+1)/SU(m)\times U(1)$. For some exemplifying cases, the massless chiral and antichiral states of $E_6$ are computed. The extent of the equivalence between different conformal invariant theories which possess equal chiral rings is analyzed.Comment: 26 pages, LaTex fil

Supergravity duals of gauge theories from F(4) gauged supergravity in six dimensions

We construct supergravity solutions dual to twisted field theories that are the worldvolume theories of D4-branes wrapped on 2, 3-cycles, and NS-fivebranes on 3-cycles. We first obtain the solutions for the Romans' six-dimensional gauged supergravity theories and then up-lift them to ten dimensions. In particular, we find solutions for field configurations with either non-Abelian fields or B-fields being excited. One of these solutions, in the massless case, is up-lifted to the massless type IIA string theory. This is the first example of such a kind. The cases studied provide new examples of the AdS/CFT duality involving twisted field theories.Comment: 26 pages, 3 figures, minor changes and references added to match the published versio

Economic Impacts of Soybean Rust on the US Soybean Sector

The spread of Asian Soybean Rust (ASR) represents a real threat to the U.S. soybean sector. We assess the potential impacts of ASR on domestic soybean production and commodity markets as well as the competitive position of the US in the soybean export market. We develop a mathematical stochastic dynamic sector model with endogenous prices to assess the economic impacts of ASR on US agriculture. The model takes into account the disease spread during the cropping season, the inherent uncertainty regarding the risk of infection, and the dichotomous decisions that farmers make (no treatment, preventive treatment, and curative treatment) facing the risk of infection. Our results suggest substantial impacts from potential ASR spread on agricultural output, prices and exports. Our simulation results suggest that substantial losses to the US soybean producers may be avoided by establishing effective soybean rust controls. ASR control policies can be particularly efficient if applied in the gateway regions on the path of the ASR spread. On the other hand, our results indicate a possible gradual shift in soybean production from lower-latitude states toward higher-latitude statesAsian Soybean Rust, Stochastic Models, Dynamic Models, Crop Production/Industries, C61, Q13,

Economic Impacts of Soybean Rust on the US Soybean Sector

The spread of Asian Soybean Rust (ASR) represents a real threat to the U.S. soybean sector. We assess the potential impacts of ASR on domestic soybean production and commodity markets as well as the competitive position of the US in the soybean export market. We develop a mathematical stochastic dynamic sector model with endogenous prices to assess the economic impacts of ASR on US agriculture. The model takes into account the disease spread during the cropping season, the inherent uncertainty regarding the risk of infection, and the dichotomous decisions that farmers make (no treatment, preventive treatment, and curative treatment) facing the risk of infection. Our results suggest substantial impacts from potential ASR spread on agricultural output, prices and exports. Our simulation results suggest that substantial losses to the US soybean producers may be avoided by establishing effective soybean rust controls. ASR control policies can be particularly efficient if applied in the gateway regions on the path of the ASR spread. On the other hand, our results indicate a possible gradual shift in soybean production from lower-latitude states toward higher-latitude states.Asian Soybean Rust, Stochastic Models, Dynamic Models, Agribusiness, Marketing, C61, Q13,

A new eclipsing binary system with a pulsating component detected by CoRoT

We report the discovery of CoRoT 102980178 (R.A.= 06:50:12.10, Dec.= -02:41:21.8, J2000) an Algol-type eclipsing binary system with a pulsating component (oEA). It was identified using a publicly available 55 day long monochromatic lightcurve from the CoRoT initial run dataset (exoplanet field). Eleven consecutive 1.26m deep total primary and the equal number of 0.25m deep secondary eclipses (at phase 0.50) were observed. The following light elements for the primary eclipse were derived: HJD_MinI= 2454139.0680 + 5.0548d x E. The lightcurve modeling leads to a semidetached configuration with the photometric mass ratio q=0.2 and orbital inclination i=85 deg. The out-of-eclipse lightcurve shows ellipsoidal variability and positive O'Connell effect as well as clear 0.01m pulsations with the dominating frequency of 2.75 c/d. The pulsations disappear during the primary eclipses, which indicates the primary (more massive) component to be the pulsating star. Careful frequency analysis reveals the second independent pulsation frequency of 0.21 c/d and numerous combinations of these frequencies with the binary orbital frequency and its harmonics. On the basis of the CoRoT lightcurve and ground based multicolor photometry, we favor classification of the pulsating component as a gamma Doradus type variable, however, classification as an SPB star cannot be excluded.Comment: 16 pages, 7 figures, 3 tables, accepted to Communications in Asteroseismolog

Territories of scarcity and creativity: a critical view of informal settlements and emerging tactics under conditions of scarcity in Nairobi, Kenya and Quito, Ecuador

This thesis explores the processes through which scarcity is constructed in informal settlements and how conditions emerging within its limits gives way to particular socio-spatial phenomena and influence the emergence of self-organisation and creative strategies from a non-expert perspective. At the same time, this thesis deconstructs these emerging tactics (reactive and transformative) in a diagrammatic way to generate a critical study of their potential for socio-spatial change that goes beyond the everyday survival. Most people associate scarcity with “not having enough” of something, most usually of a material nature. In contrast, this paper is based on the premise that scarcity is a constructed condition, therefore exploring it beyond its immediate manifestation and illustrating its discursive, distributive and socio-material components. In this line, the research uses Assemblage Theory as both an approach and a tool for analysis. This approach allows the research to depart from everyday narratives of the residents, and gradually evolve into a multi-scalar, non-linear reading of scarcity, by following leads into different realms and unpacking a series of routine events to uncover their connections to wider processes and particular elements affecting the settlement and the city as a whole. For this purpose, the research is based on a qualitative, flexible and multi-sited methodology, using different case studies as testing grounds. Collected data stems from a 11-months ethnographic fieldwork in informal settlements in Ecuador and Kenya, analysing the socio-spatial practices and strategies deployed by the different actors producing the built environment and arising from everyday and latent experiences of scarcity. The thesis examines the multi-scalar nature of these strategies, including self-building and management tactics, the mobilisation of grassroots organisations, the innovative ways of collaborating deployed by different coalitions and the reformulation of urban development policies. As outcomes of the research, the thesis will show illustrative diagrams that allow a better understanding of, firstly, the construction of scarcity in the built environment beyond its immediate manifestation and secondly, the way that emerging tactics a) improve existing conditions of scarcity, b) reinforce the status quo or c) contribute to the worsening of the original condition. Therefore, this thesis aims to offer lessons with both practical and theoretical considerations, by firstly, giving an insight into the complexity and transcalar nature of the construction of scarcity in informal settlements; secondly, by illustrating how acute conditions related to scarcity gives birth to a plethora of particular phenomena shaping the territory, social relationships and processes; and thirdly, by identifying specific characteristics within the informal that might allow for new readings of the city and possibilities for socio-spatial change under conditions of scarcity

Strategic Planning and Project Selection for IT Portfolio Management

Software project proposals, solicited from various sources across an organization, could significantly vary in strategic value, overlap in functionality, and assume conflicting technical infrastructure. Without a holistic approach toward project selection and planning, the resulting project portfolio will likely incur undue risk while delivering poor return on investment. We propose a two-stage optimization procedure. In the first stage, project characteristics such as strategic alignment, perceived benefits, cost, and risk are considered to maximize portfolio value. In the second stage, inter-project dependencies and team expertise are used to determine how projects are assigned to programs and in what sequence they should be carried out. Future extension on the proposed optimization procedure is also discussed

Impact of decitabine on immunohistochemistry expression of the putative tumor suppressor genes FHIT, WWOX, FUS1 and PTEN in clinical tumor samples.

BackgroundSince tumor suppressor gene function may be lost through hypermethylation, we assessed whether the demethylating agent decitabine could increase tumor suppressor gene expression clinically. For fragile histidine triad (FHIT), WW domain-containing oxidoreductase (WWOX), fused in sarcoma-1 (FUS1) and phosphatase and tensin homolog (PTEN), immunohistochemistry scores from pre- and post-decitabine tumor biopsies (25 patients) were correlated with methylation of the long interspersed nuclear element-1 (LINE-1) repetitive DNA element (as a surrogate for global DNA methylation) and with tumor regression.ResultsWith negative staining pre-decitabine (score = 0), the number of patients converting to positive staining post-decitabine was 1 of 1 for FHIT, 3 of 6 for WWOX, 2 of 3 for FUS1 and 1 of 10 for PTEN. In tumors with low pre-decitabine tumor suppressor gene scores (≤150), expression was higher post-treatment in 8 of 8 cases for FHIT (P = 0.014), 7 of 17 for WWOX (P = 0.0547), 7 of 12 for FUS1 (P = 0.0726), and 1 of 16 for PTEN (P = 0.2034). If FHIT, WWOX and FUS1 were considered together, median pre- versus post-decitabine scores were 60 versus 100 (P = 0.0002). Overall, tumor suppressor gene expression change did not correlate with LINE-1 demethylation, although tumors converting from negative to positive had a median decrease in LINE-1 methylation of 24%, compared to 6% in those not converting (P = 0.069). Five of 15 fully evaluable patients had reductions in tumor diameter (range 0.2% to 33.4%). Of these, three had simultaneous increases in three tumor suppressor genes (including the two patients with the greatest tumor regression) compared to 2 of 10 with tumor growth (P = 0.25).ConclusionsIn tumors with low tumor suppressor gene expression, decitabine may be associated with increased expression of the tumor suppressor genes FHIT, FUS1, and WWOX, but not PTEN