1,629 research outputs found
Studies on calcium requirements of ewes
Digitized 2007 AES.Includes bibliographical references (pages 34-35)
Canonical Solution of Classical Magnetic Models with Long-Range Couplings
We study the canonical solution of a family of classical spin
models on a generic -dimensional lattice; the couplings between two spins
decay as the inverse of their distance raised to the power , with
. The control of the thermodynamic limit requires the introduction of
a rescaling factor in the potential energy, which makes the model extensive but
not additive. A detailed analysis of the asymptotic spectral properties of the
matrix of couplings was necessary to justify the saddle point method applied to
the integration of functions depending on a diverging number of variables. The
properties of a class of functions related to the modified Bessel functions had
to be investigated. For given , and for any , and lattice
geometry, the solution is equivalent to that of the model, where the
dimensionality and the geometry of the lattice are irrelevant.Comment: Submitted for publication in Journal of Statistical Physic
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A consensus definition for lamellar macular hole
Background: A consensus on an optical coherence tomography (OCT) definition of lamellar macular hole (LMH) and similar conditions is needed.
Methods: The panel reviewed relevant peer-reviewed literature to reach a consensus on LMH definition and to differentiate LMH from other similar conditions.
Results: The panel reached a consensus on the definition of 3 clinical entities: LMH, epiretinal membrane (ERM) foveoschisis and macular pseudohole (MPH). LMH definition is based on 3 mandatory criteria and 3 optional anatomical features. The 3 mandatory criteria are the presence of irregular foveal contour, the presence of a foveal cavity with undermined edges, and the apparent loss of foveal tissue. Optional anatomical features include the presence of epiretinal proliferation, the presence of a foveal bump and the disruption of the ellipsoid line. ERM foveoschisis definition is based on 2 mandatory criteria: the presence of ERM and the presence of schisis at the level of Henle’s fiber layer. Three optional anatomical features can also be present: the presence of microcystoid spaces in the inner nuclear layer (INL), an increase of retinal thickness, and the presence of retinal wrinkling. MPH definition is based on 3 mandatory criteria and 2 optional anatomical features. Mandatory criteria include the presence of a foveal sparing ERM, the presence of a steepened foveal profile and an increased central retinal thickness. Optional anatomical features are the presence of microcystoid spaces in the INL and a normal retinal thickness.
Conclusions: The use of the proposed definitions may provide uniform language for clinicians and future research
The signal peptide of pro-opiomelancortin: Validation of a specific radioimmunoassay
The N-terminus portion of the POMC leader sequence (signal peptide) was synthesized, and an antiserum was raised against it. A radioimmunoassay was developed which is effective at a dilution of 1:500,000, and sensitive at less than 1 fmole/tube. Since leader sequences often exhibit structural homologies, and since synthetic peptides are not readily available, we resorted to an unusual procedure to establish specificity. This involved extraction of pituitary RNA, cell-free translation to produce the pre-prohormones, and purification by B-END and signal antibody affinity columns. The eluates were then tested by SDS gel electrophoresis and by multiple immunoprecipitations. All results showed that the signal antibody captured a single molecular species, approximately 30,000 in MW, which was also captured by the B-END column, and was immunoprecipitable by B-END and ACTH antisera. It therefore appears that this antibody selectively measures the POMC leader sequence and should be valuable in measuring the newly synthesized pre-prohormone.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23804/1/0000042.pd
Mesoscopic modeling of a two-phase flow in the presence of boundaries: the Contact Angle
We present a mesoscopic model, based on the Boltzmann Equation, for the
interaction between a solid wall and a non-ideal fluid. We present an analytic
derivation of the contact angle in terms of the surface tension between the
liquid-gas, the liquid-solid and the gas-solid phases. We study the dependency
of the contact angle on the two free parameters of the model, which determine
the interaction between the fluid and the boundaries, i.e. the equivalent of
the wall density and of the wall-fluid potential in Molecular Dynamics studies.
We compare the analytical results obtained in the hydrodynamical limit for
the density profile and for the surface tension expression with the numerical
simulations. We compare also our two-phase approach with some exact results for
a pure hydrodynamical incompressible fluid based on Navier-Stokes equations
with boundary conditions made up of alternating slip and no-slip strips.
Finally, we show how to overcome some theoretical limitations connected with a
discretized Boltzmann scheme and we discuss the equivalence between the surface
tension defined in terms of the mechanical equilibrium and in terms of the
Maxwell construction.Comment: 29 pages, 12 figure
Zero-g radio frequency gaging system for space shuttle propellant tanks
Radio frequency measuring system for space shuttle propellant tanks under conditions of weightlessnes
Histone citrullination represses miRNA expression resulting in increased oncogene mRNAs in somatolactotrope cells.
Peptidylarginine deiminase (PAD) enzymes convert histone arginine residues into citrulline to modulate chromatin organization and gene expression. Although PADs are expressed in anterior pituitary gland cells, their functional role and expression in pituitary adenomas is unknown. To begin to address these questions, we first examined normal human pituitaries and pituitary adenomas and found that PAD2, PAD4 and citrullinated histones are highest in prolactinomas and somatoprolactinomas. In the somatoprolactinoma-derived GH3 cell line, PADs citrullinate histone H3, which is attenuated by a pan-PAD inhibitor. RNA-sequencing and ChIP studies show that the expression of microRNAs let-7c-2, miR-23b and miR-29c is suppressed by histone citrullination. Our studies demonstrate that these miRNAs directly target the mRNA of the oncogenes HMGA, IGF-1 and N-MYC, which are highly implicated in human prolactinoma/somatoprolactinoma pathogenesis. Our results are the first to define a direct role for PAD catalyzed histone citrullination in miRNA expression, which may underlie the etiology of prolactinoma and somatoprolactinoma tumors through regulation of oncogene expression
National and Regional Implications of Targeting the Conservation Reserve
Within the Conservation Reserve (CR) program, a change in program criteria could reduce the amount of erosion material entering our nation\u27s waterways. The inclusion of land adjacent to water bodies, flowing streams, and river waterways may reduce erosion from these lands and improve water quality. These buffer strip areas, removed from production and placed in the reserve with a vegetative cover, would limit sedimentation and act to prevent upland erosion materials from reaching waterway channels, thus enhancing the programs\u27 environmental benefits. This paper analyzes the economic benefits of including buffer strups as eligible CR land, and it reviews the problems of identifying such areas
Opportunities for improving irrigation efficiency with quantitative models, soil water sensors and wireless technology
Increasingly serious shortages of water make it imperative to improve the efficiency of irrigation in agriculture, horticulture and in the maintenance of urban landscapes. The main aim of the current review is to identify ways of meeting this objective. After reviewing current irrigation practices, discussion is centred on the sensitivity of crops to water deficit, the finding that growth of many crops is unaffected by considerable lowering of soil water content and, on this basis, the creation of improved means of irrigation scheduling. Subsequently, attention is focused on irrigation problems associated with spatial variability in soil water and the often slow infiltration of water into soil, especially the subsoil. As monitoring of soil water is important for estimating irrigation requirements, the attributes of the two main types of soil water sensors and their most appropriate uses are described. Attention is also drawn to the contribution of wireless technology to the transmission of sensor outputs. Rapid progress is being made in transmitting sensor data, obtained from different depths down the soil profile across irrigated areas, to a PC that processes the data and on this basis automatically commands irrigation equipment to deliver amounts of water, according to need, across the field. To help interpret sensor outputs, and for many other reasons, principles of water processes in the soil–plant system are incorporated into simulation models that are calibrated and tested in field experiments. Finally, it is emphasized that the relative importance of the factors discussed in this review to any particular situation varies enormously
Two dimensional self-avoiding walk with hydrogen-like bonding: Phase diagram and critical behaviour
The phase diagram for a two-dimensional self-avoiding walk model on the
square lattice incorporating attractive short-ranged interactions between
parallel sections of walk is derived using numerical transfer matrix
techniques. The model displays a collapse transition. In contrast to the
standard -point model, the transition is first order. The phase diagram
in the full fugacity-temperature plane displays an additional transition line,
when compared to the -point model, as well as a critical transition at
finite temperature in the hamiltonian walk limit.Comment: 22 pages, 13 figures. To appear in Journal of Physics
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