Source Differentiated Mexican Dairy Import Demand

Mexico is a major destination of dairy exports and is the single largest importer of US dairy exports. We use a restricted source almost ideal demand system to estimate the demand for dairy products imported into Mexico. The estimation facilitates an examination of the demand for dairy imports and the results have implications for exporting firms and countries. Our estimates indicate fierce competition for the Mexican market between the US, Oceania, and “other countries†primarily from South America.dairy trade, import demand, almost ideal demand system, source differentiation, Demand and Price Analysis, International Relations/Trade, Q10, Q11, Q17,

Femtosecond pulses at 50-W average power from an Yb:YAG planar waveguide amplifier seeded by an Yb:KYW oscillator

We report the demonstration of a high-power single-side-pumped Yb:YAG planar waveguide amplifier seeded by an Yb:KYW femtosecond laser. Five passes through the amplifier yielded 700-fs pulses with average powers of 50 W at 1030 nm. A numerical simulation of the amplifier implied values for the laser transition saturation intensity, the small-signal intensity gain coefficient and the gain bandwidth of 10.0 kW cm(-2), 1.6 cm(-1), and 3.7 nm respectively, and identified gain-narrowing as the dominant pulse-shaping mechanism. (C) 2012 Optical Society of America</p

An assessment of chemical contaminants in the marine sediments of southwest Puerto Rico

This report summarizes the results of a characterization of chemical contaminants in the sediments in southwest Puerto Rico. The report is part of a project to integrate various analytical specialties to assess linkages between chemical contaminants and the condition of coral reefs. In this phase of the project, over 120 chemical contaminants were analyzed in sediments collected, including a number of organic (e.g., hydrocarbons), inorganic (e.g., metals), and biological (bacterial) compounds/analytes. The report also provides a preliminary analysis of the association between sediment contaminants and coral species richness. Overall, the levels of chemical contaminants in the study area between Guanica Bay and the town of La Parguera were fairly low. At most of the sites sampled, particularly adjacent to the town of La Parguera, concentrations of organic and inorganic contaminants were below the median values from NOAA’s National Status and Trends Program, which monitors the Nation’s coastal and estuarine waters for chemical contaminants. Elevated levels of a number of contaminant classes were seen at the two sites sampled within Guanica Bay. An initial analysis of modeled PAH (hydrocarbon) data and coral species richness (reef building species) indicated a strong negative correlation between the presence of PAHs in the sediments and coral species richness. Additional work is needed to assess possible reasons for this observed pattern. (PDF contains 126 pages)

Characterisation of oil sludges from different sources before treatment: high-field nuclear magnetic resonance (NMR) in the determination of oil and water content

Oil sludges are wastes from the oil industry containing complex mixtures of oil hydrocarbons, water, sediments, and heavy metals. These wastes are of main importance for the petroleum industry since it is estimated that more than a billion tons have been stored worldwide. There are several types of oil sludges, but the oil tank bottom sludges are the most studied. Therefore, it is necessary to analyse a variety of oil sludges to establish a detail characterisation, with fast and reliable methods before selecting a suitable treatment. Five sludges were analysed in this study: an oil drilling, oil refinery, oil-water separator, and two waste engine oil sludges. This is a rare report detailing the use of high-field (500 MHz) nuclear magnetic resonance (NMR) to determine oil and water contents in oil sludges, which are more commonly analysed by low-field NMR (below 100 MHz). The proposed NMR procedure was validated by the analysis of oil-water calibration standards (experimental errors < 15%). There was a good agreement among the data obtained from the 1D proton spectra and the Carr-Purcell- Meiboom-Gill (CPMG) T2 decays (percentage differences < 5%). The T2 decays data showed that all sludges had only two components attributed to oil and water, and their relative ratios were determined. The sediment content was determined by the oven-drying method, and the oil hydrocarbon fractions and trace elements were assessed. The oil sludges presented different ranges in the oil, water, sediment and heavy metals contents. The higher presence of C10-C18 aliphatic fractions in the oil from the sludges was an indicator of the potential to be reused as diesel fuel. The sludges had potentially toxic elements (PTEs) values under the limit of the landfilling standards established by the European Union, except for the WSS sludge. Ca and Fe had the highest concentrations in all sludges, which are characteristic of these wastes. The techniques used in this study can be an alternative for a rapid characterisation of the oil sludges, so their most appropriate treatment can be established

Formation rates of core collapse SNe and GRBs

We study the evolution of stars that may be the progenitors of long-soft gamma-ray burst (GRBs) -- rotating naked helium stars presumed to have lost their envelopes to winds or companions. Our aim is to investigate the formation and development of single and binary systems and from this population evaluate the rates of interesting individual species. Using a rapid binary evolution algorithm, that enables us to model the most complex binary systems and to explore the effect of metallicity on GRB production, we draw the following conclusions. First we find that, if we include an approximate treatment of angular momentum transport by mass loss, the resulting spin rates for single stars become too low to form a centrifugally supported disc that can drive a GRB engine. Second massive stars in binaries result in enough angular momentum -- due to spin-orbit tidal interactions -- to form a centrifugally supported disc and are thus capable of supplying a sufficient number of progenitors. This holds true even if only a small fraction of bursts are visible to a given observer and the GRB rate is several hundred times larger than the observed rate. Third low-metallicity stars aid the formation of a rapidly rotating, massive helium cores at collapse and so their evolution is likely to be affected by the local properties of the ISM. This effect could increase the GRB formation rate by a factor of 5-7 at Z=Z_solar/200. Finally we quantify the effects of mass loss, common-envelope evolution and black-hole formation and show that more stringent constraints to many of these evolution parameters are needed in order to draw quantitative conclusions from population synthesis work.Comment: 37 pages, 14 figures, MNRAS in pres

Deep-water chemosynthetic ecosystem research during the Census of Marine Life Decade and Beyond: A Proposed Deep-Ocean Road Map

The ChEss project of the Census of Marine Life (2002–2010) helped foster internationally-coordinated studies worldwide focusing on exploration for, and characterization of new deep-sea chemosynthetic ecosystem sites. This work has advanced our understanding of the nature and factors controlling the biogeography and biodiversity of these ecosystems in four geographic locations: the Atlantic Equatorial Belt (AEB), the New Zealand region, the Arctic and Antarctic and the SE Pacific off Chile. In the AEB, major discoveries include hydrothermal seeps on the Costa Rica margin, deepest vents found on the Mid-Cayman Rise and the hottest vents found on the Southern Mid-Atlantic Ridge. It was also shown that the major fracture zones on the MAR do not create barriers for the dispersal but may act as trans-Atlantic conduits for larvae. In New Zealand, investigations of a newly found large cold-seep area suggest that this region may be a new biogeographic province. In the Arctic, the newly discovered sites on the Mohns Ridge (71°N) showed extensive mats of sulfur-oxidisng bacteria, but only one gastropod potentially bears chemosynthetic symbionts, while cold seeps on the Haakon Mossby Mud Volcano (72°N) are dominated by siboglinid worms. In the Antarctic region, the first hydrothermal vents south of the Polar Front were located and biological results indicate that they may represent a new biogeographic province. The recent exploration of the South Pacific region has provided evidence for a sediment hosted hydrothermal source near a methane-rich cold-seep area. Based on our 8 years of investigations of deep-water chemosynthetic ecosystems worldwide, we suggest highest priorities for future research: (i) continued exploration of the deep-ocean ridge-crest; (ii) increased focus on anthropogenic impacts; (iii) concerted effort to coordinate a major investigation of the deep South Pacific Ocean – the largest contiguous habitat for life within Earth's biosphere, but also the world's least investigated deep-ocean basin

Deficiency of the zinc finger protein ZFP106 causes motor and sensory neurodegeneration

Acknowledgements We are indebted to Jim Humphries, JennyCorrigan, LizDarley, Elizabeth Joynson, Natalie Walters, Sara Wells and the whole necropsy, histology, genotyping and MLC ward 6 teams at MRC Harwell for excellent technical assistance. We thank the staff of the WTSI Illumina Bespoke Team for the RNA-seq data, the Sanger Mouse Genetics Project for the initial mouse characterization and Dr David Adams for critical reading of the manuscript. We also thank KOMP for the mouse embryonic stem cells carrying the knockout first promoter-less allele (tm1a(KOMP)Wtsi) within Zfp016. Conflict of Interest statement. None declared. Funding This work was funded by the UK Medical Research Council (MRC) to A.A.-A. and a Motor Neurone Disease Association (MNDA) project grant to A.A.-A. and EMCF. D.L.H.B. is a Wellcome Trust Senior Clinical Scientist Fellow and P.F. is a MRC/MNDA Lady Edith Wolfson Clinician Scientist Fellow. Funding to pay the Open Access publication charges for this article was provided by the MRC grant number: MC_UP_A390_1106.Peer reviewedPublisher PD

The discovery of new deep-sea hydrothermal vent communities in the Southern ocean and implications for biogeography

Since the first discovery of deep-sea hydrothermal vents along the Gala´pagos Rift in 1977, numerous vent sites and endemic faunal assemblages have been found along mid-ocean ridges and back-arc basins at low to mid latitudes. These discoveries have suggested the existence of separate biogeographic provinces in the Atlantic and the North West Pacific, the existence of a province including the South West Pacific and Indian Ocean, and a separation of the North East Pacific, North East Pacific Rise, and South East Pacific Rise. The Southern Ocean is known to be a region of high deep-sea species diversity and centre of origin for the global deep-sea fauna. It has also been proposed as a gateway connecting hydrothermal vents in different oceans but is little explored because of extreme conditions. Since 2009 we have explored two segments of the East Scotia Ridge (ESR) in the Southern Ocean using a remotely operated vehicle. In each segment we located deep-sea hydrothermal vents hosting high-temperature black smokers up to 382.8uC and diffuse venting. The chemosynthetic ecosystems hosted by these vents are dominated by a new yeti crab (Kiwa n. sp.), stalked barnacles, limpets, peltospiroid gastropods, anemones, and a predatory sea star. Taxa abundant in vent ecosystems in other oceans, including polychaete worms (Siboglinidae), bathymodiolid mussels, and alvinocaridid shrimps, are absent from the ESR vents. These groups, except the Siboglinidae, possess planktotrophic larvae, rare in Antarctic marine invertebrates, suggesting that the environmental conditions of the Southern Ocean may act as a dispersal filter for vent taxa. Evidence from the distinctive fauna, the unique community structure, and multivariate analyses suggest that the Antarctic vent ecosystems represent a new vent biogeographic province. However, multivariate analyses of species present at the ESR and at other deep-sea hydrothermal vents globally indicate that vent biogeography is more complex than previously recognised