3,124 research outputs found
Applying Transaction Cost Economics: A Note on Biomass Supply Chains
Agricultural supply chains, especially those from producer to first handler, are relatively mature institutions. While agricultural economists often observe the evolution of marketing structures in developing nations, it is a rare opportunity to research a developing market within North America. The emerging bioenergy industryĂąâŹâwhich relies on non-food crops such as strawĂąâŹâprovides the potential to research and potentially impact the development of new supply chains. Here, we briefly review the literature related to biomass supply chains, pose a transaction cost approach to studying their development, and then discuss the procurement strategies of an industry leader: the Iogen Corporation.biomass supply chains, organization, transaction cost, Agribusiness, Demand and Price Analysis, Production Economics,
Cross-Hedging Fishmeal: Exploring Corn and Soybean Meal Futures Contracts
During 2006 the fishmeal price nearly doubled from 900MT. The objective of this research is to determine the optimal cross-hedge ratio between fishmeal and soybean meal and corn, and corresponding hedging weight between corn and soybean. Results indicate all hedging weight should be placed on the corn futures contract. This is an interesting result since prior fishmeal cross-hedging research has not analyzed the corn futures contract as a risk management mechanism.Crop Production/Industries, Risk and Uncertainty,
Global blue carbon accumulation in tidal wetlands increases with climate change
Coastal tidal wetlands produce and accumulate significant amounts of organic carbon (C) that help to mitigate climate change. However, previous data limitations have prevented a robust evaluation of the global rates and mechanisms driving C accumulation. Here, we go beyond recent soil C stock estimates to reveal global tidal wetland C accumulation and predict changes under relative sea level rise, temperature and precipitation. We use data from literature study sites and our new observations spanning wide latitudinal gradients and 20 countries. Globally, tidal wetlands accumulate 53.65 (95%CI: 48.52â59.01) Tg C yrâ1, which isâŒ30% of the organic C buried on the ocean floor. Modeling based on current climatic drivers and under projected emissions scenarios revealed a net increase in the global C accumulation by 2100. This rapid increase is driven by sea level rise in tidal marshes, and higher temperature and precipitation in mangroves. Countries with large areas of coastal wetlands, like Indonesia and Mexico, are more susceptible to tidal wetland C losses under climate change, while regions such as Australia, Brazil, the USA and China will experience a significant C accumulation increase under all projected scenarios
Fission and cluster decay of Sr nucleus in the ground-state and formed in heavy-ion reactions
Calculations for fission and cluster decay of are presented for
this nucleus to be in its ground-state or formed as an excited compound system
in heavy-ion reactions. The predicted mass distribution, for the dynamical
collective mass transfer process assumed for fission of , is clearly
asymmetric, favouring -nuclei. Cluster decay is studied within a
preformed cluster model, both for ground-state to ground-state decays and from
excited compound system to the ground-state(s) or excited states(s) of the
fragments.Comment: 14 pages LaTeX, 5 Figures available upon request Submitted to Phys.
Rev.
A CD3-Specific Antibody Reduces Cytokine Production and Alters Phosphoprotein Profiles in Intestinal Tissues From Patients With Inflammatory Bowel Disease
NOTICE: this is the authorâs version of a work that was accepted for publication in Gastroenterology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in GASTROENTEROLOGY, 10.1053/j.gastro.2014.03.04
Infrared problem for the Nelson model on static space-times
We consider the Nelson model with variable coefficients and investigate the
problem of existence of a ground state and the removal of the ultraviolet
cutoff. Nelson models with variable coefficients arise when one replaces in the
usual Nelson model the flat Minkowski metric by a static metric, allowing also
the boson mass to depend on position. A physical example is obtained by
quantizing the Klein-Gordon equation on a static space-time coupled with a
non-relativistic particle. We investigate the existence of a ground state of
the Hamiltonian in the presence of the infrared problem, i.e. assuming that the
boson mass tends to 0 at infinity
The velocity dispersion and mass function of the outer halo globular cluster Palomar 4
We obtained precise line-of-sight radial velocities of 23 member stars of the
remote halo globular cluster Palomar 4 (Pal 4) using the High Resolution
Echelle Spectrograph (HIRES) at the Keck I telescope. We also measured the mass
function of the cluster down to a limiting magnitude of V~28 mag using archival
HST/WFPC2 imaging. We derived the cluster's surface brightness profile based on
the WFPC2 data and on broad-band imaging with the Low-Resolution Imaging
Spectrometer (LRIS) at the Keck II telescope. We find a mean cluster velocity
of 72.55+/-0.22 km/s and a velocity dispersion of 0.87+/-0.18 km/s. The global
mass function of the cluster, in the mass range 0.55<=M<=0.85 M_solar, is
shallower than a Kroupa mass function and the cluster is significantly depleted
in low-mass stars in its center compared to its outskirts. Since the relaxation
time of Pal 4 is of the order of a Hubble time, this points to primordial mass
segregation in this cluster. Extrapolating the measured mass function towards
lower-mass stars and including the contribution of compact remnants, we derive
a total cluster mass of 29800 M_solar. For this mass, the measured velocity
dispersion is consistent with the expectations of Newtonian dynamics and below
the prediction of Modified Newtonian Dynamics (MOND). Pal 4 adds to the growing
body of evidence that the dynamics of star clusters in the outer Galactic halo
can hardly be explained by MOND.Comment: 17 pages, accepted for publication in MNRAS; Fig. 8 surface
brightness/density data at github.com/matthiasjfrank/pal4_surface_brightnes
Resolution of the type material of the Asian elephant, Elephas maximus Linnaeus, 1758 (Proboscidea, Elephantidae)
The understanding of Earthâs biodiversity depends critically on the accurate identification and nomenclature of
species. Many species were described centuries ago, and in a surprising number of cases their nomenclature or type
material remain unclear or inconsistent. A prime example is provided by Elephas maximus, one of the most iconic
and well-known mammalian species, described and named by Linnaeus (1758) and today designating the Asian
elephant. We used morphological, ancient DNA (aDNA), and high-throughput ancient proteomic analyses to
demonstrate that a widely discussed syntype specimen of E. maximus, a complete foetus preserved in ethanol, is
actually an African elephant, genus Loxodonta. We further discovered that an additional E. maximus syntype,
mentioned in a description by John Ray (1693) cited by Linnaeus, has been preserved as an almost complete skeleton
at the Natural History Museum of the University of Florence. Having confirmed its identity as an Asian elephant
through both morphological and ancient DNA analyses, we designate this specimen as the lectotype of E. maximus
Quark Gluon Plasma an Color Glass Condensate at RHIC? The perspective from the BRAHMS experiment
We review the main results obtained by the BRAHMS collaboration on the
properties of hot and dense hadronic and partonic matter produced in
ultrarelativistic heavy ion collisions at RHIC. A particular focus of this
paper is to discuss to what extent the results collected so far by BRAHMS, and
by the other three experiments at RHIC, can be taken as evidence for the
formation of a state of deconfined partonic matter, the so called
quark-gluon-plasma (QGP). We also discuss evidence for a possible precursor
state to the QGP, i.e. the proposed Color Glass Condensate.Comment: 32 pages, 18 figure
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