Irrigation technology and commercialization of rice in the Gambia: effects on income and nutrition

Rice trade Gambia., Irrigation Economic aspects Gambia., Agricultural innovations Gambia., Food supply Gambia., Income Gambia.,

SuperCam, a 64-pixel heterodyne imaging array for the 870 micron atmospheric window

We report on the development of SuperCam, a 64 pixel, superheterodyne camera designed for operation in the astrophysically important 870 micron atmospheric window. SuperCam will be used to answer fundamental questions about the physics and chemistry of molecular clouds in the Galaxy and their direct relation to star and planet formation. The advent of such a system will provide an order of magnitude increase in mapping speed over what is now available and revolutionize how observational astronomy is performed in this important wavelength regime. Unlike the situation with bolometric detectors, heterodyne receiver systems are coherent, retaining information about both the amplitude and phase of the incident photon stream. From this information a high resolution spectrum of the incident light can be obtained without multiplexing. SuperCam will be constructed by stacking eight, 1x8 rows of fixed tuned, SIS mixers. The IF output of each mixer will be connected to a low-noise, broadband MMIC amplifier integrated into the mixer block. The instantaneous IF bandwidth of each pixel will be ~2 GHz, with a center frequency of 5 GHz. A spectrum of the central 500 MHz of each IF band will be provided by the array spectrometer. Local oscillator power is provided by a frequency multiplier whose output is divided between the pixels by using a matrix of waveguide power dividers. The mixer array will be cooled to 4K by a closed-cycle refrigeration system. SuperCam will reside at the Cassegrain focus of the 10m Heinrich Hertz telescope (HHT). A prototype single row of the array will be tested on the HHT in 2006, with the first engineering run of the full array in late 2007. The array is designed and constructed so that it may be readily scaled to higher frequencies.Comment: 12 pages, 14 figures, to be published in the Proceedings of SPIE Vol. 6275, "Astronomical Telescopes and Instrumentation, Millimeter and Submillimeter Detectors and Instrumentation for Astronomy III

Effects of chronic exercise on feelings of energy and fatigue: A quantitative synthesis

The authors investigated the effect of chronic exercise on feelings of energy and fatigue using metaanalytic techniques. Chronic exercise increased feelings of energy and lessened feelings of fatigue compared with control conditions by a mean effect delta of 0.37. The effect varied according to the presence or absence of a placebo control or whether chronic exercise was completed alone or in combination with an additional therapy. Investigations that used a placebo control and examined chronic exercise alone found no effect of chronic exercise on feelings of energy and fatigue. Certain placebo controls may increase feelings of energy and lessen feelings of fatigue when used with older adults or people with psychological distress. The results highlight the need for research identifying the most useful control conditions for accurately interpreting mental health outcome data obtained in chronic exercise investigations

Test and integration results from SuperCam: a 64-pixel array receiver for the 350 GHz atmospheric window

We report on laboratory testing and telescope integration of SuperCam, a 64 pixel imaging spectrometer designed for operation in the astrophysically important 870 micron atmospheric window. SuperCam will be used to answer fundamental questions about the physics and chemistry of molecular clouds in the Galaxy and their direct relation to star and planet formation. The Supercam key project is a fully sampled Galactic plane survey covering over 500 square degrees of the Galaxy in ^(12)CO(3-2) and ^(13)CO(3-2) with 0.3 km/s velocity resolution. SuperCam will have several times more pixels than any existing spectroscopic imaging array at submillimeter wavelengths. The exceptional mapping speed that will result, combined with the efficiency and angular resolution provided by the HHT will make SuperCam a powerful instrument for probing the history of star formation in our Galaxy and nearby galaxies. SuperCam will be used to answer fundamental questions about the physics and chemistry of molecular clouds in the Galaxy and their direct relation to star and planet formation. Through Galactic surveys, particularly in CO and its isotopomers, the impact of Galactic environment on these phenomena will be realized. These studies will serve as “finder charts” for future focused research (e.g. with ALMA) and markedly improve the interpretation, and enhance the value of numerous contemporary surveys. In the past, all heterodyne focal plane arrays have been constructed using discrete mixers, arrayed in the focal plane. SuperCam reduces cryogenic and mechanical complexity by integrating multiple mixers and amplifiers into a single array module with a single set of DC and IF connectors. These modules are housed in a closed-cycle cryostat with a 1.5W capacity 4K cooler. The Supercam instrument is currently undergoing laboratory testing with four of the eight mixer array modules installed in the cryostat (32 pixels). Work is now underway to perform the necessary modifications at the 10m Heinrich Hertz Telescope to accept the Supercam system. Supercam will be installed in the cassegrain cabin of the HHT, including the optical system, IF processing, spectrometers and control electronics. Supercam will be integrated with the HHT during the 2009-2010 observing season with 32 pixels installed. The system will be upgraded to 64 pixels during the summer of 2010 after assembly of the four additional mixer modules is completed

First observations with SuperCam and future plans

Supercam is a 345 GHz, 64-pixel heterodyne imaging array for the Heinrich Hertz Submillimeter Telescope (HHSMT). By integrating SIS mixer devices with Low Noise Ampliers (LNAs) in 8 - 1x8 pixel modules, the size needed for the cryostat and the complexity of internal wiring is signicantly reduced. All subsystems including the optics, cryostat, bias system, IF boxes, and spectrometer have been integrated for all 64 pixels. In the spring of 2012, SuperCam was installed on the HHSMT for an engineering run where it underwent system level tests and performed rst light observations. In the fall of 2012 SuperCam will begin a 500 square degree survey of the Galactic Plane in ^(12)CO J=3-2. This large-scale survey will help answer fundamental questions about the formation, physical conditions, and energetics of molecular clouds within the Milky Way. The data set will be available via the web to all interested researchers

Observation of High-Energy Astrophysical Neutrinos in Three Years of IceCube Data

A search for high-energy neutrinos interacting within the IceCube detector between 2010 and 2012 provided the first evidence for a high-energy neutrino flux of extraterrestrial origin. Results from an analysis using the same methods with a third year (2012-2013) of data from the complete IceCube detector are consistent with the previously reported astrophysical flux in the 100 TeV - PeV range at the level of $10^{-8}\, \mathrm{GeV}\, \mathrm{cm}^{-2}\, \mathrm{s}^{-1}\, \mathrm{sr}^{-1}$ per flavor and reject a purely atmospheric explanation for the combined 3-year data at $5.7 \sigma$. The data are consistent with expectations for equal fluxes of all three neutrino flavors and with isotropic arrival directions, suggesting either numerous or spatially extended sources. The three-year dataset, with a livetime of 988 days, contains a total of 37 neutrino candidate events with deposited energies ranging from 30 to 2000 TeV. The 2000 TeV event is the highest-energy neutrino interaction ever observed.Comment: 8 pages, 5 figures. Accepted by PRL. The event catalog, event displays, and other data tables are included after the final page of the article. Changed from the initial submission to reflect referee comments, expanding the section on atmospheric backgrounds, and fixes offsets of up to 0.9 seconds in reported event times. Address correspondence to: J. Feintzeig, C. Kopper, N. Whitehor

Irrigation Technology and Commercialization of Rice in the Gambia: Effects on Income and Nutrition

With its focus in irrigation technology and commercialization of rice in West Africa, this study addresses the question of how agricultural growth in Sub-Saharan Africa may improve food security. Over the last few decades in Africa, rice has ranked second after maize among cereal that have contributed to the overall growth of cereal output. In West Africa, rice imports have grown rapidly during the last two decades. Future decisions on irrigation investments and technology choices will be critical importance in view of numerous past failures and excessive costs of irrigation in Sub-Saharan Africa. This research by Joachim Von Braun, Detlev Puetz, and Patrick Webb is to be seen against the backdrop of policy priorities resulting from the earlier work of IFPRI and its collaborators on accelerating food production in Sub-Saharan Africa. The study resulted highlight the measurable positive effect that incremental income in the hands of the poorest had on nutritional improvement. It is encouraging to learn that yield levels comparable to the highest yields in Asia can be obtained in irrigation schemes in Africa, but the issue of lowering irrigation costs remains a crucial one. In another emphasis of the study is the identification of very high substitution effects between irrigated crops and rainfed crops because of swift labor movements between the crops. The study comprehensively traces the nutritional effects of technological change in the Gambia via production, income, employment, and consumption effects in innovative ways. It stresses the need to consider cause and effect relationships in complex household economic systems. Having a multidisciplinary team of economist, anthropologists, and public health experts work on these issues has proven very useful. A particularly noteworthy aspect of this study is the complex relationship between agricultural productivity and labor utilization. An increase in labor productivity may induce both fundamental changes in the intrahousehold system of division of labor and major shifts of labor between agriculture subsectors. Emphasis is required in program design on breaking the labor bottlenecks in this environment under seasonal stress. Among the important lessons of the study are that technological change is a key to improving food security at the household level in this west African environment, and that irrigated rice with appropriate technological consideration in the riverine areas can make a substantial contribution. To incorporate women farmers into the technologically driven modernization process, women must have access to the means that permit them to use the new technologies- especially access to inputs and credit. Food- security improvements with wear rural health services need to be alleviated jointly to reap maximum benefits from the agricultural commercialization process. The latter point confirms findings of comparable research by IFPRI in Guatemala and Kenya that health and sanitation services in rural health services need to be alleviated jointly to reap maximum sanitations services in rural areas have to move in tandem with the agriculture modernization process in order to reduce the nutrition problem along the hunger problem