48 research outputs found
Transportation and Quality Adjusted Basis: Does the Law of One Price Hold for Feeder Cattle?
Feeder calf prices are examined from a national video auction sales from 2004-2006. Many cattle, lot, and market characteristics significantly impact feeder cattle basis. Auction prices were adjusted for quality differences and for transportation costs and compared across regions. Basis was significantly different after the adjustment from region to region.feeder cattle prices, law of one price, video auctions, Demand and Price Analysis, Farm Management, Livestock Production/Industries, Marketing,
Snowmass White Paper: String Theory and Particle Physics
We review recent developments and outstanding questions regarding connecting
the top-down UV complete physical framework of string theory with the observed
physics of the Standard Model and beyond the Standard Model physics,
emphasizing the global nonperturbative framework of F-theory and general
lessons from UV physics. This paper, prepared for the TF01 conveners of the
Snowmass 2022 process, provides a brief synopsis of this important area,
focusing on ongoing developments and opportunities.Comment: 34 pages (17 pages text +17 pages references
Rheology of Ring Polymer Melts: From Linear Contaminants to Ring/Linear Blends
Ring polymers remain a major challenge to our current understanding of
polymer dynamics. Experimental results are difficult to interpret because of
the uncertainty in the purity and dispersity of the sample. Using both
equilibrium and non-equilibrium molecular dynamics simulations we have
systematically investigated the structure, dynamics and rheology of perfectly
controlled ring/linear polymer blends with chains of such length and
flexibility that the number of entanglements is up to about 14 per chain, which
is comparable to experimental systems examined in the literature. The smallest
concentration at which linear contaminants increase the zero-shear viscosity of
a ring polymer melt of these chain lengths by 10% is approximately one-fifth of
their overlap concentration. When the two architectures are present in equal
amounts the viscosity of the blend is approximately twice as large as that of
the pure linear melt. At this concentration the diffusion coefficient of the
rings is found to decrease dramatically, while the static and dynamic
properties of the linear polymers are mostly unaffected. Our results are
supported by a primitive path analysis.Comment: 5 pages, 4 figures, accepted by PR
Magnetic field assisted fractionation of nonmagnetic colloids in ferrofluid
IEEE Transactions on Magnetics, 43(6): pp. 2692-2694.Flocculation of nonmagnetic colloidal particles in ferrofluid while in the presence of an external uniform magnetic field is investigated
experimentally. Magnetic nanoparticles in ferrofluid create magnetic interactions between nonmagnetic colloidal particles. It is demonstrated
that nonmagnetic particles can be fractionated by size much more efficiently in the presence of these magnetic interactions
Molecular Dynamics Simulation Study of Nonconcatenated Ring Polymers in a Melt: I. Statics
Molecular dynamics simulations were conducted to investigate the structural
properties of melts of nonconcatenated ring polymers and compared to melts of
linear polymers. The longest rings were composed of N=1600 monomers per chain
which corresponds to roughly 57 entanglement lengths for comparable linear
polymers. For the rings, the radius of gyration squared was found to scale as N
to the 4/5 power for an intermediate regime and N to the 2/3 power for the
larger rings indicating an overall conformation of a crumpled globule. However,
almost all beads of the rings are "surface beads" interacting with beads of
other rings, a result also in agreement with a primitive path analysis
performed in the following paper (DOI: 10.1063/1.3587138). Details of the
internal conformational properties of the ring and linear polymers as well as
their packing are analyzed and compared to current theoretical models.Comment: 15 pages, 14 figure
Arraying nonmagnetic colloids by magnetic nanoparticle assemblers
IEEE Transactions On Magnetics, 42(10): pp. 3548-3553.We review our recent work on the manipulation and assembly of nonmagnetic colloidal materials above magnetically programmable
surface templates. The nonmagnetic materials are manipulated by a fluid dispersion of magnetic nanoparticles, known as ferrofluid.
Particle motion is guided by a program of magnetic information stored in a substrate in the form of a lithographically patterned template
of micromagnets. We show how dynamic control over the motion of nonmagnetic particles can be accomplished by applying rotating
external magnetic field. This unexpectedly large degree of control over particle motion can be used to manipulate large ensembles of
particles in parallel, potentially with local control over particle trajectory
Validation of high gradient magnetic field based drug delivery to magnetizable implants under flow
IEEE Transactions on Biomedical Engineering, 55(2): pp. 643-649.The drug-eluting stent’s increasingly frequent occurrence
late stage thrombosis have created a need for new strategies
for intervention in coronary artery disease. This paper demonstrates
further development of our minimally invasive, targeted
drug delivery system that uses induced magnetism to administer
repeatable and patient specific dosages of therapeutic agents to specific
sites in the human body. Our first aim is the use of magnetizable
stents for the prevention and treatment of coronary restenosis;
however, future applications include the targeting of tumors, vascular
defects, and other localized pathologies. Future doses can
be administered to the same site by intravenous injection. This
implant-based drug delivery system functions by placement of a
weakly magnetizable stent or implant at precise locations in the
cardiovascular system, followed by the delivery of magnetically
susceptible drug carriers. The stents are capable of applying high
local magnetic field gradients within the body, while only exposing
the body to a modest external field. The local gradients created
within the blood vessel create the forces needed to attract and hold
drug-containing magnetic nanoparticles at the implant site. Once
these particles are captured, they are capable of delivering therapeutic
agents such as antineoplastics, radioactivity, or biological
cells
Cross-ancestry GWAS meta-analysis identifies six breast cancer loci in African and European ancestry women
Our study describes breast cancer risk loci using a cross-ancestry GWAS approach. We first identify variants that are associated with breast cancer at P \u3c 0.05 from African ancestry GWAS meta-analysis (9241 cases and 10193 controls), then meta-analyze with European ancestry GWAS data (122977 cases and 105974 controls) from the Breast Cancer Association Consortium. The approach identifies four loci for overall breast cancer risk [1p13.3, 5q31.1, 15q24 (two independent signals), and 15q26.3] and two loci for estrogen receptor-negative disease (1q41 and 7q11.23) at genome-wide significance. Four of the index single nucleotide polymorphisms (SNPs) lie within introns of genes (KCNK2, C5orf56, SCAMP2, and SIN3A) and the other index SNPs are located close to GSTM4, AMPD2, CASTOR2, and RP11-168G16.2. Here we present risk loci with consistent direction of associations in African and European descendants. The study suggests that replication across multiple ancestry populations can help improve the understanding of breast cancer genetics and identify causal variants
Cross-ancestry GWAS meta-analysis identifies six breast cancer loci in African and European ancestry women.
Our study describes breast cancer risk loci using a cross-ancestry GWAS approach. We first identify variants that are associated with breast cancer at P < 0.05 from African ancestry GWAS meta-analysis (9241 cases and 10193 controls), then meta-analyze with European ancestry GWAS data (122977 cases and 105974 controls) from the Breast Cancer Association Consortium. The approach identifies four loci for overall breast cancer risk [1p13.3, 5q31.1, 15q24 (two independent signals), and 15q26.3] and two loci for estrogen receptor-negative disease (1q41 and 7q11.23) at genome-wide significance. Four of the index single nucleotide polymorphisms (SNPs) lie within introns of genes (KCNK2, C5orf56, SCAMP2, and SIN3A) and the other index SNPs are located close to GSTM4, AMPD2, CASTOR2, and RP11-168G16.2. Here we present risk loci with consistent direction of associations in African and European descendants. The study suggests that replication across multiple ancestry populations can help improve the understanding of breast cancer genetics and identify causal variants