N=3 Warped Compactifications

Orientifolds with three-form flux provide some of the simplest string examples of warped compactification. In this paper we show that some models of this type have the unusual feature of D=4, N=3 spacetime supersymmetry. We discuss their construction and low energy physics. Although the local form of the moduli space is fully determined by supersymmetry, to find its global form requires a careful study of the BPS spectrum.Comment: 27 pages, v2: 32pp., RevTeX4, fixed factors, slightly improved sections 3D and 4B, v3: added referenc

Exactly solvable model of superstring in Ramond-Ramond plane wave background

We describe in detail the solution of type IIB superstring theory in the maximally supersymmetric plane-wave background with constant null Ramond-Ramond 5-form field strength. The corresponding light-cone Green-Schwarz action found in hep-th/0112044 is quadratic in both bosonic and fermionic coordinates. We find the spectrum of the light-cone Hamiltonian and the string representation of the supersymmetry algebra. The superstring Hamiltonian has a ``harmonic-oscillator'' form in both the string-oscillator and the zero-mode parts and thus has discrete spectrum in all 8 transverse directions. We analyze the structure of the zero-mode sector of the theory, establishing the precise correspondence between the lowest-lying ``massless'' string states and the type IIB supergravity fluctuation modes in the plane-wave background. The zero-mode spectrum has certain similarity to the supergravity spectrum in AdS_5 x S^5 of which the plane-wave background is a special limit. We also compare the plane-wave string spectrum with expected form of the light-cone gauge spectrum of superstring in AdS_5 x S^5.Comment: 33 pages, latex. v4: minor sign corrections in (1.5) and (3.62), to appear in PR

Introduction to M Theory and AdS/CFT Duality

An introductory survey of some of the developments that have taken place in superstring theory in the past few years is presented. The main focus is on three particular dualities. The first one is the appearance of an 11th dimension in the strong coupling limit of the type IIA theory, which give rise to M theory. The second one is the duality between the type IIB theory compactified on a circle and M theory on a two-torus. The final topic is an introduction to the recently proposed duality between superstring theory or M theory on certain anti de Sitter space backgrounds and conformally invariant quantum field theories.Comment: 26 pages; To be published in the Proceedings of a conference held in Corfu, Greece in September 1998. v2: reference adde

Global agricultural intensification during climate change: A role for genomics

Summary: Agriculture is now facing the 'perfect storm' of climate change, increasing costs of fertilizer and rising food demands from a larger and wealthier human population. These factors point to a global food deficit unless the efficiency and resilience of crop production is increased. The intensification of agriculture has focused on improving production under optimized conditions, with significant agronomic inputs. Furthermore, the intensive cultivation of a limited number of crops has drastically narrowed the number of plant species humans rely on. A new agricultural paradigm is required, reducing dependence on high inputs and increasing crop diversity, yield stability and environmental resilience. Genomics offers unprecedented opportunities to increase crop yield, quality and stability of production through advanced breeding strategies, enhancing the resilience of major crops to climate variability, and increasing the productivity and range of minor crops to diversify the food supply. Here we review the state of the art of genomic-assisted breeding for the most important staples that feed the world, and how to use and adapt such genomic tools to accelerate development of both major and minor crops with desired traits that enhance adaptation to, or mitigate the effects of climate change. &gt

Reproductive phenology of Dipteryx odorata (Aubl.) Willd (Fabaceae) in two forest areas in the Central Amazon

Long term phenological studies in tropical forests are scarce. A phenological study of Dipteryx odorata was carried out from 1974 to 2000 in two areas of Amazon Forest: Reserva Florestal Ducke (RFD) and Estação Experimental de Silvicultura Tropical (EEST). The objective was to compare the phenological patterns between the two areas, to verify the regularity of flowering and fruiting over a period of 27 years, and to verify the influence of climatic factors in these events. Five trees were marked in the RFD and five in the EEST; and were observed monthly for the presence of flowers, unripe and ripe fruits. The flowering and unripe fruiting presented an irregular pattern in both areas, and also varied with regard to duration and period of occurrence between years and seasons. Nevertheless, they presented similar frequency of occurrence during the 27 years of observation. On the other hand, the production of ripe fruits presented a different pattern, with three year intervals without ripe fruits in the RFD, and seven year intervals in the EEST. We concluded that the frequency of flowering and unripe fruiting was annual, and the frequency of occurrence of ripe fruiting was supra-annual, with an irregular pattern, and a duration from intermediate to extended. We also observed the occurrence of one to three year intervals between flowering and unripe fruiting episodes, and one to seven year intervals between episodes with ripe fruiting. The influence of climatic factors in the patterns observed was not clear. We suggest the rational use of natural products extracted from Dipteryx odorata, the "cumaru", especially the fruits, and the development of more long term studies, fundamental for understanding the reproductive phenological patterns as well as the resource offering patterns in tropical forests.Estudos fenológicos de longa duração em florestas tropicais são raros. Foi realizado o acompanhamento fenológico de Dipteryx odorata, no período de 1974 à 2000, em duas áreas de floresta amazônicaa Reserva Florestal Ducke (RFD) e Estação Experimental de Silvicultura Tropical (EEST). O objetivo foi observar os padrões fenológicos nas duas áreas, verificar a regularidade da floração e frutificação num período de 27 anos e a influência dos fatores climáticos nestes eventos. Foram marcados cinco indivíduos na RFD e cinco na EEST e observados quanto à produção de flores, frutos imaturos e maduros. A floração e a produção de frutos imaturos apresentaram padrão irregular nas duas áreas observadas, variando quanto a época de ocorrência e a duração entre anos e estações, mas apresentaram freqüência de ocorrência similar nos 27 anos observados. Para a fenofase frutos maduros este padrão foi diferente, com intervalos de até três anos sem ocorrência de frutos maduros, na RFD e de sete anos na EEST. Conclui-se que a freqüência de ocorrência das fenofases de floração e frutos imaturos foi anual e a de frutos maduros supra-anual, todas com padrão irregular e duração de intermediária a prolongada. Ocorreu variação de um a três anos entre episódios de floração e frutos imaturos e de um a sete anos entre episódios de frutos maduros, não ficando evidente, nesta análise, a influência dos fatores climáticos nos padrões observados. Sugere-se o uso racional dos produtos derivados de Dipteryx odorata, o cumaru, especialmente quanto à exploração de seus frutos e o desenvolvimento de mais estudos de longa duração, fundamentais para entender os padrões fenológicos reprodutivos e de oferta de recursos em florestas tropicais

The Sudbury Neutrino Observatory

The Sudbury Neutrino Observatory is a second generation water Cherenkov detector designed to determine whether the currently observed solar neutrino deficit is a result of neutrino oscillations. The detector is unique in its use of D2O as a detection medium, permitting it to make a solar model-independent test of the neutrino oscillation hypothesis by comparison of the charged- and neutral-current interaction rates. In this paper the physical properties, construction, and preliminary operation of the Sudbury Neutrino Observatory are described. Data and predicted operating parameters are provided whenever possible.Comment: 58 pages, 12 figures, submitted to Nucl. Inst. Meth. Uses elsart and epsf style files. For additional information about SNO see http://www.sno.phy.queensu.ca . This version has some new reference

Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study

A41 Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study In: Addiction Science & Clinical Practice 2017, 12(Suppl 1): A4

Measurement of the νe and total 8B solar neutrino fluxes with the Sudbury Neutrino Observatory phase-III data set

This paper details the solar neutrino analysis of the 385.17-day phase-III data set acquired by the Sudbury Neutrino Observatory (SNO). An array of 3He proportional counters was installed in the heavy-water target to measure precisely the rate of neutrino-deuteron neutral-current interactions. This technique to determine the total active 8B solar neutrino flux was largely independent of the methods employed in previous phases. The total flux of active neutrinos was measured to be 5.54-0.31+0.33(stat.)-0.34+0.36(syst.)×106 cm-2 s-1, consistent with previous measurements and standard solar models. A global analysis of solar and reactor neutrino mixing parameters yielded the best-fit values of Δm2=7.59-0.21+0.19×10 -5eV2 and θ=34.4-1.2+1.3degrees