EVALUATION OF HEDGING IN THE PRESENCE OF CROP INSURANCE AND GOVERNMENT LOAN PROGRAMS

This research evaluates the interaction of new alternative insurance designs, forward pricing tools and the government revenue protection program while assuming a government loan program is in place. A numerical analysis is conducted using a revenue simulation model that incorporates futures prices, basis, and yield variability. Three crop insurance designs at 75 percent of yield guarantee are evaluated. Optimal futures and at-the-money put option hedge ratios are derived for expected utility maximizing of soybean producers. Sensitivity to loan rate levels are examined. Our results suggest that loan programs profoundly alter the optimal producer strategy.Agricultural Finance, Marketing,

IMPLICATIONS OF CROP YIELD AND REVENUE INSURANCE FOR PRODUCER HEDGING

New types of crop insurance have expanded the tools from which crop producers may choose to manage risk. Little is known regarding how these products interact with futures and options. This analysis examines optimal futures and put ratios in the presence of four alternative insurance coverages. An analytical model investigates the comparative statics of the relationship between hedging and insurance. Additional numerical analysis is conducted which incorporates futures price, basis, and yield variability. Yield insurance is found to have a positive effect on hedging levels. Revenue insurance tends to result in slightly lower hedging demand than would occur given the same level of yield insurance coverage.Risk and Uncertainty,

A new family, Coryphoridae (Ephemeroptera: Ephemerelloidea), and description of the winged and egg stages of Coryphorus

A new family Coryphoridae is proposed in the superfamily Ephemerelloidea for the monotypic genus Coryphorus. Characters that distinguish Coryphoridae from all other Ephemerelloidea are discussed. The male imago, male subimago, female imago, and egg of Coryphorus aquilus Peters are described for the first time.Se propone a Coryphoridae como una nueva familia de Ephemerelloidea para el genero monotipico Coryphorus. Se discuten los caracteres que distinguen a Coryphoridae del resto de los Ephemerelloidea. Se describen por primera vez el imago macho, subimago macho, imago hembra y huevo de Coryphorus aquilus Peters

MECHANISTIC STUDY OF A RUTHENIUM HYDRIDE COMPLEX OF TYPE [RuH(CO)(N-N)(PR3)2]+ AS CATALYST PRECURSOR FOR THE HYDROFORMYLATION REACTION OF 1-HEXENE

Indexación: Web of Science; Scopus; Scielo.The catalytic activity of systems of type [RuH(CO)(N-N)(PR3)(2)](+) was evaluated in the hydroformylation reaction of 1-hexene. The observed activity is explained through a reaction mechanism on the basis of the quantum theory. The mechanism included total energy calculations for each of the intermediaries of the elemental steps considered in the catalytic cycle. The deactivation of the catalyst precursors takes place via dissociation of the polypyridine ligand and the subsequent formation of thermodynamically stable species, such as RuH(CO)(3)(PPh3)(2) and RuH3(CO)(PPh3)(2), which interrupt the catalytic cycle. In addition, the theoretical study allows to explain the observed regioselectivity which is defined in two steps: (a) the hydride migration reaction with an anti-Markovnikov orientation to produce the alkyl-linear-complex (3.1a), which is more stable by 19.4 kJ/mol than the Markovnikov orientation (alkyl-branched-complex) (3.1b); (b) the carbon monoxide insertion step generates the carbonyl alkyl-linear specie (4.1a) which is more stable by 9.5 kJ/mol than the alternative species (4.1b), determining the preferred formation of heptanal in the hydroformylation of 1-hexene. Palabras clavehttp://ref.scielo.org/db4yc

The Infrared Extinction Law at Extreme Depth in a Dark Cloud Core

We combined sensitive near-infrared data obtained with ground-based imagers on the ESO NTT and VLT telescopes with space mid-infrared data acquired with the IRAC imager on the Spitzer Space Telescope to calculate the extinction law A_\lambda/A_K as a function of \lambda between 1.25 and 7.76 micron to an unprecedented depth in Barnard 59, a star forming, dense core located in the Pipe Nebula. The ratios A_\lambda/A_K were calculated from the slopes of the distributions of sources in color-color diagrams \lambda-K vs. H-K. The distributions in the color-color diagrams are fit well with single slopes to extinction levels of A_K ~ 7 (A_V ~ 59 mag). Consequently, there appears to be no significant variation of the extinction law with depth through the B59 line of sight. However, when slopes are translated into the relative extinction coefficients A_\lambda/A_K, we find an extinction law which departs from the simple extrapolation of the near-infrared power law extinction curve, and agrees more closely with a dust extinction model for a cloud with a total to selective absorption R_V=5.5 and a grain size distribution favoring larger grains than those in the diffuse ISM. Thus, the difference we observe could be possibly due to the effect of grain growth in denser regions. Finally, the slopes in our diagrams are somewhat less steep than those from the study of Indebetouw et al. (2005) for clouds with lower column densities, and this indicates that the extinction law between 3 and 8 micron might vary slightly as a function of environment.Comment: 22 pages manuscript, 4 figures (2 multipart), 1 tabl

Diatoms as a paleoproductivity proxy in the NW Iberian coastal upwelling system (NE Atlantic)

The objective of the current work is to improve our understanding of how water column diatom's abundance and assemblage composition is seasonally transferred from the photic zone to seafloor sediments. To address this, we used a dataset derived from water column, sediment trap and surface sediment samples recovered in the NW Iberian coastal upwelling system. Diatom fluxes (2.2 (+/- 5.6) 10(6) valves m(-2) d(-1)) represented the majority of the siliceous microorganisms sinking out from the photic zone during all studied years and showed seasonal variability. Contrasting results between water column and sediment trap diatom abundances were found during downwelling periods, as shown by the unexpectedly high diatom export signals when diatom- derived primary production achieved their minimum levels. They were principally related to surface sediment remobilization and intense Minho and Douro river discharge that constitute an additional source of particulate matter to the inner continental shelf. In fact, contributions of allochthonous particles to the sinking material were confirmed by the significant increase of both benthic and freshwater diatoms in the sediment trap assemblage. In contrast, we found that most of the living diatom species blooming during highly productive upwelling periods were dissolved during sinking, and only those resistant to dissolution and the Chaetoceros and Leptocylindrus spp. resting spores were susceptible to being exported and buried. Fur-thermore, Chaetoceros spp. dominate during spring-early summer, when persistent northerly winds lead to the upwelling of nutrient-rich waters on the shelf, while Leptocylindrus spp. appear associated with late-summer upwelling relaxation, characterized by water column stratification and nutrient depletion. These findings evidence that the contributions of these diatom genera to the sediment's total marine diatom assemblage should allow for the reconstruction of different past upwelling regimes.CAIBEX [CTM2007-66408-C02-01/MAR]; REIMAGE [CTM2011-30155-C03-03]; Spanish Government, EXCAPA project [10MDS402013PR]; Xunta de Galicia; EU FEDER [INTERREG 2009/2011-0313/RAIA/E]; RAIA. co [INTERREG2011/2013-052/RAIA.co/1E]; CALIBERIA project [PTDC/MAR/102045/2008]; Fundacao para a Ciencia e a Tecnologia (FCT-Portugal) [COMPETE/FEDER-FCOMP01-0124-FEDER-010599]; Xunta de Galicia (Spain) [SFRH/BPD/111433/2015]; FCT (Portugal) [SFRH/BPD/111433/2015]; [SFRH/BD/88439/2012

Hunting Galaxies to (and for) Extinction

In studies of star-forming regions, near-infrared excess (NIRX) sources--objects with intrinsic colors redder than normal stars--constitute both signal (young stars) and noise (e.g. background galaxies). We hunt down (identify) galaxies using near-infrared observations in the Perseus star-forming region by combining structural information, colors, and number density estimates. Galaxies at moderate redshifts (z = 0.1 - 0.5) have colors similar to young stellar objects (YSOs) at both near- and mid-infrared (e.g. Spitzer) wavelengths, which limits our ability to identify YSOs from colors alone. Structural information from high-quality near-infrared observations allows us to better separate YSOs from galaxies, rejecting 2/5 of the YSO candidates identified from Spitzer observations of our regions and potentially extending the YSO luminosity function below K of 15 magnitudes where galaxy contamination dominates. Once they are identified we use galaxies as valuable extra signal for making extinction maps of molecular clouds. Our new iterative procedure: the Galaxies Near Infrared Color Excess method Revisited (GNICER), uses the mean colors of galaxies as a function of magnitude to include them in extinction maps in an unbiased way. GNICER increases the number of background sources used to probe the structure of a cloud, decreasing the noise and increasing the resolution of extinction maps made far from the galactic plane.Comment: 16 pages and 16 figures. Accepted for publication in ApJ. Full resolution version at http://www.cfa.harvard.edu/COMPLETE/papers/Foster_HuntingGalaxies.pd

A FLAMINGOS Deep Near Infrared Imaging Survey of the Rosette Complex I: Identification and Distribution of the Embedded Population

We present the results of a deep near-infrared imaging survey of the Rosette Complex. We studied the distribution of young embedded sources using a variation of the Nearest Neighbor Method applied to a carefully selected sample of near-infrared excess (NIRX) stars which trace the latest episode of star formation in the complex. Our analysis confirmed the existence of seven clusters previously detected in the molecular cloud, and identified four more clusters across the complex. We determined that 60% of the young stars in the complex and 86% of the stars within the molecular cloud are contained in clusters, implying that the majority of stars in the Rosette formed in embedded clusters. We compare the sizes, infrared excess fractions and average extinction towards individual clusters to investigate their early evolution and expansion. We found that the average infrared excess fraction of clusters increases as a function of distance from NGC 2244, implying a temporal sequence of star formation across the complex. This sequence appears to be primordial, possibly resulting from the formation and evolution of the molecular cloud and not from the interaction with the HII region.Comment: Accepted by Astrophysical Journa

Thermal Jeans fragmentation within 1000 AU in OMC-1S

We present subarcsecond 1.3 mm continuum ALMA observations towards the Orion Molecular Cloud 1 South (OMC-1S) region, down to a spatial resolution of 74 AU, which reveal a total of 31 continuum sources. We also present subarcsecond 7 mm continuum VLA observations of the same region, which allow to further study fragmentation down to a spatial resolution of 40 AU. By applying a Mean Surface Density of Companions method we find a characteristic spatial scale at ~560 AU, and we use this spatial scale to define the boundary of 19 `cores' in OMC-1S as groupings of millimeter sources. We find an additional characteristic spatial scale at ~2900 AU, which is the typical scale of the filaments in OMC-1S, suggesting a two-level fragmentation process. We measured the fragmentation level within each core and find a higher fragmentation towards the southern filament. In addition, the cores of the southern filament are also the densest (within 1100 AU) cores in OMC-1S. This is fully consistent with previous studies of fragmentation at spatial scales one order of magnitude larger, and suggests that fragmentation down to 40 AU seems to be governed by thermal Jeans processes in OMC-1S.Comment: Accepted to Ap