Specification of a Regional-National Recursive Model for IIASA/FAP's Iowa Task 2 Case Study

The major objectives of the Food and Agriculture Program (FAP) of the International Institute for Applied Systems Analysis are to evaluate the nature and dimensions of the world food situation, to identify factors affecting it, and to suggest policy alternatives at the national, regional, and global levels to alleviate current food problems and to prevent future ones. The present shortrun problems of policy are explored in FAP's Task 1, "Strategies: National Policy Models for Food and Agriculture" by means of a set of descriptive, general-equilibrium, price-endogenous national models of various countries linked in a consistent international framework. From a longer term perspective the food problem acquires added dimensions; and questions of availability of resources to produce adequate food, efficiency of techniques, and environmental consequences become important. These questions are addressed by FAP's Task 2 "Technological Transformations in Agriculture: Resource Limitations and Environmental Consequences". Quantitative knowledge of the interactions between agriculture and the environment requires a great deal of detailed information on the site-specific nature of resource inputs and on alternative land use practices. A general-equilibrium approach to such types of investigation is not empirically feasible. The research methodology of Task 2 is to formulate a series of region-specific case studies within a general recursive programming framework. The regional-national recursive model specified in this paper represents the intermediate stage of development of the Iowa Case Study. The Iowa model has been specified by a team of researchers including Dr. Earl 0. Heady, James Langley, Andrew Morton, and Burton English of the Center for Agricultural and Rural Development, Iowa State University, and Wen-yuan Huang and Klaus Alt of the Natural Resources Economics Division, U.S. Department of Agriculture. Work is continuing on the specification of various components of the Iowa model along with preliminary applications in accordance with the framework of FAP's Task 2

Birthweight, HIV exposure and infant feeding as predictors of malnutrition in Botswanan infants

Background: A better understanding of the nutritional status of infants who are HIV-Exposed-Uninfected (HEU) and HIV-Unexposed-Uninfected (HUU) during their first 1000 days is a key to improving population health, particularly in sub-Saharan Africa. Methods: A cross-sectional study compared nutritional status, feeding practices and determinants of nutritional status of HEU and HUU infants residing in representative selected districts in Botswana during their first 1000 days of life. Four hundred and thirteen infants (37.3% HIV16 exposed), aged 6-24 months attending routine child health clinics were recruited. Anthropometric, 24-hour dietary intake and socio-demographic data was collected. Anthropometric z-scores were calculated using 2006 WHO growth standards. Modelling of the determinants of malnutrition was undertaken using logistic regression. Results: Overall, prevalence of stunting, wasting and underweight were 10.4%, 11.9% and 10.2% respectively. HEU infants were more likely to be underweight (15.6% vs. 6.9%), (p<0.01) and stunted (15.6% vs. 7.3%), (p<0.05) but not wasted (p= 0.14) than HUU infants. HEU infants tended to be formula fed (89.4%) whereas HUU infants tended to breastfeed (89.6%) for the first six months (p<0.001). Significant predictors of nutritional status were HIV exposure, birthweight, birth length, Apgar score and mother/caregiver’s education with little influence of socioeconomic status. Conclusions: HEU infants aged 6-24 months had worse nutritional status compared to HUU infants. Low birthweight was the main predictor of undernutrition in this population. Optimisation of infants’ nutritional status should focus on improving birthweight. In addition, specific interventions should target HEU infants in order to eliminate growth disparity between HEU and HUU infants

Non-real zeros of derivatives of meromorphic functions

A number of results are proved concerning non-real zeros of derivatives of real and strictly non-real meromorphic functions in the plane

An integrated host-microbiome response to atrazine exposure mediates toxicity in Drosophila

The gut microbiome produces vitamins, nutrients, and neurotransmitters, and helps to modulate the host immune system-and also plays a major role in the metabolism of many exogenous compounds, including drugs and chemical toxicants. However, the extent to which specific microbial species or communities modulate hazard upon exposure to chemicals remains largely opaque. Focusing on the effects of collateral dietary exposure to the widely used herbicide atrazine, we applied integrated omics and phenotypic screening to assess the role of the gut microbiome in modulating host resilience in Drosophila melanogaster. Transcriptional and metabolic responses to these compounds are sex-specific and depend strongly on the presence of the commensal microbiome. Sequencing the genomes of all abundant microbes in the fly gut revealed an enzymatic pathway responsible for atrazine detoxification unique to Acetobacter tropicalis. We find that Acetobacter tropicalis alone, in gnotobiotic animals, is sufficient to rescue increased atrazine toxicity to wild-type, conventionally reared levels. This work points toward the derivation of biotic strategies to improve host resilience to environmental chemical exposures, and illustrates the power of integrative omics to identify pathways responsible for adverse health outcomes

Coastal scenic assessment and tourism management in western Cuba

Coastal scenic assessments via checklist tables (18 natural, 8 human related parameters), can provide benchmark measures regarding desirable/non-desirable beach conditions and also classify sites. The scenic value for 43 sites in western Cuba was investigated, with the aim of helping managers improve bathing areas, especially for tourism purposes. Sites were categorised from Class 1, (top grade scenery), between La Habana and Matanzas, as extremely attractive, with white sand, turquoise water and additional scenic elements. Class 2 sites were located in Varadero, and their high scores were greatly due to appropriate human interventions, e.g. beach nourishment and dune restoration works. Classes 3 to 5 (the latter having very poor scenery), included sites with low scores for natural parameters. For these sites, coastal managers can do little to alleviate scenic impact, apart from addressing the human parameters, where improvement is possible, e.g. by litter removal together with the present chaotic protective structures

A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007

We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access area to figures, tables at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000

Microwave determination of the quasiparticle scattering time in YBa2Cu3O6.95

We report microwave surface resistance (Rs) measurements on two very-high-quality YBa2Cu3O6.95 crystals which exhibit extremely low residual loss at 1.2 K (2-6 μΩ at 2 GHz), a broad, reproducible peak at around 38 K, and a rapid increase in loss, by 4 orders of magnitude, between 80 and 93 K. These data provide one ingredient in the determination of the temperature dependence of the real part of the microwave conductivity, σ1(T), and of the quasiparticle scattering time. The other necessary ingredient is an accurate knowledge of the magnitude and temperature dependence of the London penetration depth, λ(T). This is derived from published data, from microwave data of Anlage, Langley, and co-workers and from, high-quality μSR data. We infer, from a careful analysis of all available data, that λ2(0)/λ2(T) is well approximated by the simple function 1-t2, where t=T/Tc, and that the low-temperature data are incompatible with the existence of an s-wave, BCS-like gap. Combining the Rs and λ(T) data, we find that σ1(T), has a broad peak around 32 K with a value about 20 times that at Tc. Using a generalized two-fluid model, we extract the temperature dependence of the quasiparticle scattering rate which follows an exponential law, exp(T/T0), where T0≊12 K, for T between 15 and 84 K. Such a temperature dependence has previously been observed in measurements of the nuclear spin-lattice relaxation rate. Both the uncertainties in our analysis and the implications for the mechanism of high-temperature superconductivity are discussed

Bedmap2: improved ice bed, surface and thickness datasets for Antarctica

We present Bedmap2, a new suite of gridded products describing surface elevation, ice-thickness and the seafloor and subglacial bed elevation of the Antarctic south of 60° S. We derived these products using data from a variety of sources, including many substantial surveys completed since the original Bedmap compilation (Bedmap1) in 2001. In particular, the Bedmap2 ice thickness grid is made from 25 million measurements, over two orders of magnitude more than were used in Bedmap1. In most parts of Antarctica the subglacial landscape is visible in much greater detail than was previously available and the improved data-coverage has in many areas revealed the full scale of mountain ranges, valleys, basins and troughs, only fragments of which were previously indicated in local surveys. The derived statistics for Bedmap2 show that the volume of ice contained in the Antarctic ice sheet (27 million km3) and its potential contribution to sea-level rise (58 m) are similar to those of Bedmap1, but the mean thickness of the ice sheet is 4.6% greater, the mean depth of the bed beneath the grounded ice sheet is 72 m lower and the area of ice sheet grounded on bed below sea level is increased by 10%. The Bedmap2 compilation highlights several areas beneath the ice sheet where the bed elevation is substantially lower than the deepest bed indicated by Bedmap1. These products, along with grids of data coverage and uncertainty, provide new opportunities for detailed modelling of the past and future evolution of the Antarctic ice sheets