1,923 research outputs found

    FAPRI 2000 World Agricultural Outlook

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    The Food and Agricultural Policy Research Institute (FAPRI) prepares a preliminary agricultural outlook on world agricultural production, consumption, and trade every fall. This is followed by an outside review, re-evaluation of projections, and completion of the final baseline in January. The FAPRI 2000 World Agricultural Outlook presents these final projections for world agricultural markets. A companion volume, the FAPRI 2000 U.S. Agricultural Outlook, presents the U.S. component of the baseline. FAPRI projections assume average weather patterns worldwide, existing policy, and policy commitments under current trade agreements. FAPRI projections do not include conjectures on potential policy changes, such as those resulting from the likely eastward enlargement of the European Union (EU). The baseline predicts recovery of world agricultural production, consumption, and trade, but with remaining price weakness for crops. Stock-to-use ratios in world crop markets remain high despite the strong recovery of Asian and Latin American economies. Above-average yields kept world production high relative to demand in 1999. In contrast, pork and beef prices are increasing significantly above their 1999 level. The physical volume of U.S. agricultural exports is projected to reverse the downward trend of fiscal year (FY) 1999, whereas the value of agricultural exports continue to decline for one more year before recovering because of low crop prices in 2000/01. World crop trade is projected to increase by 55 million metric tons (mmt) in the coming decade, with the United States capturing 49 percent of the expanded market, but still unable to increase its market share by a large percentage. Following this expansion of the market, grain prices increase by 35 percent in the projection period, but still stay well below the peak of 1995/96. The increase in world crop trade reflects the increasing specialization occurring in world agriculture. Increased market access and land scarcity in many Asian economies induce them to import grains and oilseeds to meet their feed demand. Developing Asia remains the fastest growing market for corn in the next decade. With implementation of Agenda 2000 reforms, the EU will reduce its wheat domestic price relative to the world price and will export wheat without subsidies after 2004, constraining gains in market shares for the United States. EU barley exports will expand significantly in the coming years but are likely to be constrained by General Agreement on Tariffs and Trade (GATT) commitments on export subsidies after 2004. World meat trade will increase by 31 percent over the next decade. The United States has become a competitive producer and exporter of meat products. In the coming decade, the United States will experience the largest meat export growth rates among major exporters of beef, pork, and broilers. U.S. exporters capture more than 70 percent of the growth in trade, increasing their share of the combined meat markets from 23 percent in 1999 to 37 percent in 2009. Meat imports are recovering and expanding rapidly in Japan, South Korea, and Taiwan. In Japan, the share of imports in consumption increases from 38 percent in the 1990s to 49 percent at the end of the next decade. Taiwan meat imports will triple from 1990-1999 levels to 2000-2009 levels, driven by imports of beef, non muscle pork products, and the opening of the poultry market. Recovery of Asian food demand will prompt dairy prices to grow by about 1 percent per year over the next decade. Total milk production is projected to increase, with particularly strong growth in the United States, Mexico, Argentina, and Brazil. Most of the growth occurs through yield increases. Per capita cheese consumption is expected to grow by 1 to 2 percent a year in most countries.Crop Production/Industries, Livestock Production/Industries,

    Particle-hole asymmetric ferromagnetism and spin textures in the triangular Hubbard-Hofstadter model

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    In a lattice model subject to a perpendicular magnetic field, when the lattice constant is comparable to the magnetic length, one enters the "Hofstadter regime," where continuum Landau levels become fractal magnetic Bloch bands. Strong mixing between bands alters the nature of the resulting quantum phases compared to the continuum limit; lattice potential, magnetic field, and Coulomb interaction must be treated on equal footing. Using determinant quantum Monte Carlo (DQMC) and density matrix renormalization group (DMRG) techniques, we study this regime numerically in the context of the Hubbard-Hofstadter model on a triangular lattice. In the field-filling phase diagram, we find a broad wedge-shaped region of ferromagnetic ground states for filling factor ν≲1\nu \lesssim 1, bounded by incompressible states at filling factor ν=1\nu = 1. For magnetic field strengths Φ/Φ0≲0.4\Phi/\Phi_0 \lesssim 0.4, we observe signatures of SU(2) quantum Hall ferromagnetism in the lowest magnetic Bloch band; however, we find no numerical evidence for conventional quantum Hall skyrmions. At large fields Φ/Φ0≳0.4\Phi/\Phi_0 \gtrsim 0.4, above the ferromagnetic wedge, we observe a low-spin metallic region with spin correlations peaked at small momenta. We argue that the phenomenology of this region likely results from exchange interaction mixing fractal Hofstadter subbands. The phase diagram derived beyond the continuum limit points to a rich landscape to explore interaction effects in magnetic Bloch bands.Comment: 15 pages, 15 figure

    Immediate Blood Draw for CD4+ Cell Count Is Associated with Linkage to Care in Durban, South Africa: Findings from Pathways to Engagement in HIV Care

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    Background Timely linkage to care by newly-diagnosed HIV+ individuals remains a significant challenge to achieving UNAIDS 90-90-90 goals. Current World Health Organization (WHO) guidelines recommend initiating anti-retroviral treatment (ART) regardless of CD4+ count, with priority given to those with CD4+ <350 cells/μl. We evaluated the impact of not having a day-of-diagnosis CD4+ count blood draw, as recommended by South African guidelines, on time to linkage, using data from a prospective cohort study. Methods Individuals (N = 2773) were interviewed prior to HIV counseling and testing at three public sector primary care clinics in the greater Durban area; 785 were newly-diagnosed and eligible for the cohort study; 459 (58.5%) joined and were followed for eight months with three structured assessments. Linkage to care, defined as returning to clinic for CD4+ count results, and day-of-diagnosis blood draw were self-reported. Results Overall, 72.5% did not have a day-of-diagnosis CD4+ count blood draw, and 19.2% of these never returned. Compared with a day-of-diagnosis blood draw, the adjusted hazard ratio of linkage (AHRlinkage) associated with not having day-of-diagnosis blood draw was 0.66 (95%CI: 0.51, 0.85). By 4 months, 54.8% of those without day-of-diagnosis blood draw vs. 75.2% with one were linked to care (chi-squared p = 0.004). Of those who deferred blood draw, 48.3% cited clinic-related and 51.7% cited personal reasons. AHRlinkage was 0.60 (95%CI: 0.44, 0.82) for clinic-related and 0.53 (95%CI: 0.38, 0.75) for personal reasons relative to having day-of-diagnosis blood draw. Conclusions Newly-diagnosed HIV+ individuals who did not undergo CD4+ count blood draw on the day they were diagnosed—regardless of the reason for deferring—had delayed linkage to care relative to those with same-day blood draw. To enhance prompt linkage to care even when test and treat protocols are implemented, all diagnostic testing required before ART initiation should be performed on the same day as HIV testing/diagnosis. This may require modifying clinic procedures to enable overnight blood storage if same-day draws cannot be performed, and providing additional counseling to encourage newly-diagnosed individuals to complete day-of-diagnosis testing. Tracking HIV+ individuals via clinic registries should commence immediately from diagnosis to reduce these early losses to care

    The Hydrogen Epoch of Reionization Array Dish I: Beam Pattern Measurements and Science Implications

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    The Hydrogen Epoch of Reionization Array (HERA) is a radio interferometer aiming to detect the power spectrum of 21 cm fluctuations from neutral hydrogen from the Epoch of Reionization (EOR). Drawing on lessons from the Murchison Widefield Array (MWA) and the Precision Array for Probing the Epoch of Reionization (PAPER), HERA is a hexagonal array of large (14 m diameter) dishes with suspended dipole feeds. Not only does the dish determine overall sensitivity, it affects the observed frequency structure of foregrounds in the interferometer. This is the first of a series of four papers characterizing the frequency and angular response of the dish with simulations and measurements. We focus in this paper on the angular response (i.e., power pattern), which sets the relative weighting between sky regions of high and low delay, and thus, apparent source frequency structure. We measure the angular response at 137 MHz using the ORBCOMM beam mapping system of Neben et al. We measure a collecting area of 93 m^2 in the optimal dish/feed configuration, implying HERA-320 should detect the EOR power spectrum at z~9 with a signal-to-noise ratio of 12.7 using a foreground avoidance approach with a single season of observations, and 74.3 using a foreground subtraction approach. Lastly we study the impact of these beam measurements on the distribution of foregrounds in Fourier space.Comment: 13 pages, 9 figures. Replaced to match accepted ApJ versio

    Curated genome annotation of Oryza sativa ssp. japonica and comparative genome analysis with Arabidopsis thaliana

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    We present here the annotation of the complete genome of rice Oryza sativa L. ssp. japonica cultivar Nipponbare. All functional annotations for proteins and non-protein-coding RNA (npRNA) candidates were manually curated. Functions were identified or inferred in 19,969 (70%) of the proteins, and 131 possible npRNAs (including 58 antisense transcripts) were found. Almost 5000 annotated protein-coding genes were found to be disrupted in insertional mutant lines, which will accelerate future experimental validation of the annotations. The rice loci were determined by using cDNA sequences obtained from rice and other representative cereals. Our conservative estimate based on these loci and an extrapolation suggested that the gene number of rice is ~32,000, which is smaller than previous estimates. We conducted comparative analyses between rice and Arabidopsis thaliana and found that both genomes possessed several lineage-specific genes, which might account for the observed differences between these species, while they had similar sets of predicted functional domains among the protein sequences. A system to control translational efficiency seems to be conserved across large evolutionary distances. Moreover, the evolutionary process of protein-coding genes was examined. Our results suggest that natural selection may have played a role for duplicated genes in both species, so that duplication was suppressed or favored in a manner that depended on the function of a gene
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