8,627 research outputs found
Seroepidemiological studies of herpesvirus-associated diseases of marine turtles: Fibropapillomatosis and lung-eye-trachea disease
We have developed immunological tests that can identify marine turtles in Florida (green and loggerhead) that have been exposed
to the LETV herpesvirus. The seroepidemiological data collected provides critical evidence about the relationship between
infection with the FP-associated herpesvirus and the LETV herpesvirus. The data supports the hypothesis that LETV and FPHV
infections are independent infections of marine turtles. The data shows that wild green turtles in Florida are exposed to the
LETD-associated herpesvirus, which is the first description ofLETV infection in free-ranging marine turtles. To our knowledge,
the antigenic proteins identified in this study are not only the first proteins from a reptilian herpesvirus to be cloned and
expressed, but they represent the first reptilian herpesvirus proteins to be identified as immunogenic in their host species. (16 page document
Further strategies for evaluating the etiological role of a tumor-associated herpesvirus in marine turtle fibropapillomatosis
In 1992, an interdisciplinary research team headquartered at the University of Florida
began studies in key targeted areas of fibropapillomatosis (FP) etiology and
pathogenesis. At that time, little was known about FP outside of field studies
documenting its prevalence in different areas of the world and studies of tumor
histopathology. Our primary objective was to develop a broad-based scientific
understanding of FP by applying principles of tumor biology, immunology, pathology,
virology, molecular biology, and epidemiology to FP in the green turtle, Chelonia
mydas. Long-term goals included the development of assays for FP and study of any
role of environmental co-factors in the disease. This report is a continuation of that
effort and the results reported here bring us closer to understanding the role of a
tumor-associated herpesvirus in marine turtle fibropapillomatosis.
This research has demonstrated that marine turtle herpesviruses can persist for
extended periods of time as infectious agents in the marine environment and that wild
green turtles in Florida are exposed to the LETD-associated herpesvirus. This is the
first description of LETV infection in free-ranging. marine turtles. In addition, data is
presented that supports the hypothesis that LETV and FPHV infections are
independent. These data reveal new levels of complexity that must be addressed
before reliable serodiagnostic assays for herpesvirus infections of chelonians can be
developed for widespread application. The results reported here also raise new
concerns about the potential impact of infections by new herpesviruses on populations
of wild marine turtles, an area which has previously been unexplored by turtle
biologists. (8 page document
VIRAL ONCOLYSIS: INCREASED IMMUNOGENICITY OF HOST CELL ANTIGEN ASSOCIATED WITH INFLUENZA VIRUS
A2G mice could be solidly immunized against the Ehrlich ascites tumor by single intraperitoneal injections of homogenized and lyophilized tumor cells which had been infected with oncolytic strains of influenza A virus. Similar homogenates from noninfected tumor cells were not immunogenic, even when mixed with egg-grown virus. The immunizing principle in viral oncolysates could not be separated from the oncolytic virus by differential centrifugation or adsorption to and elution from red cells. It could be inhibited by antibody raised in rabbits against the egg-grown oncolytic virus. This reaction showed serologic specificity. Thus, the immunogenicity of an oncolysate produced with the WSA strain of neurotropic influenza virus could be inhibited by rabbit anti-WSA, but not by rabbit antibody to the TUR strain of fowl plague virus. Conversely, the immunogenicity of an oncolysate prepared with the TUR strain could be inhibited by rabbit anti-TUR, but not by anti-WSA. When mice were preimmunized (primed) with egg-grown WSA virus, their antitumor response to a later injection of WSA oncolysate was of the anamnestic type. Priming with egg-grown influenza B virus had no such effect. It was concluded that the immunogenicity of certain host cell components was greatly increased by incorporation into the makeup of the oncolytic virus
The feasibility of radiolabeling for human serum albumin (HSA) adsorption studies
Human serum albumin (HSA) was labeled in various ways and with different radioactive labels (Technetium-99m and Iodine-125). Characterization with electrophoresis on polyacryl gel and immunoelectrophoresis did not reveal differences between labeled and nonlabeled HSA. The release of the label from labeled proteins in phosphate buffer (pH 7.4) was studied as a function of time. 125I-labeled proteins were stable and 99mTc-labeled proteins showed different stabilities depending on the labeling method which was used. The adsorption behavior of labeled HSA and HSA onto polystyrene (PS) and silicon rubber (SR) was studied by using two methods. It appeared that all labeled HSA compounds showed a preferential adsorption onto PS (and SR) substrates. The 99mTc-labeled HSA showed a high value of the preferential adsorption factor (Ï 1). The Ï value for 125I-labeled HSA was about 1.4. It was also shown that Ï was dependent on the kind of substrate used. The methods developed to determine preferential adsorption of labeled proteins compared to their nonlabeled analogs are also generally applicable for different types of compounds
Densely integrated photonic devices based on microring resonators for use in access networks
A reconfigurable optical add-drop multiplexer as well as a 1x4x4 reconfigurable λ router, designed for use in the second telecom window, are demonstrated. The devices that each have a footprint less than 2 mm are based on thermally tunable vertically coupled microring resonators fabricated in /
The linear barycentric rational quadrature method for Volterra integral equations
We introduce two direct quadrature methods based on linear rational interpolation for solving general Volterra integral equations of the second kind. The first, deduced by a direct application of linear barycentric rational quadrature given in former work, is shown to converge at the same rate as the rational quadrature rule but is costly on long integration intervals. The second, based on a composite version of this quadrature rule, loses one order of convergence but is much cheaper. Both require only a sample of the involved functions at equispaced nodes and yield an infinitely smooth solution of most classical examples with machine precision
Densely integrated microring resonator based photonic devices for use in access networks
Two reconfigurable optical add-drop multiplexers, operating in the second or third telecom window, as well as a 1x4x4 reconfigurable λ-router operating in the second telecom window, are demonstrated. The devices have a footprint less than 2 mm2 and are based on thermally tunable vertically coupled microring resonators fabricated in Si3N4/SiO2
Pathogenic, Molecular, and Immunological Properties of a Virus Associated with Sea Turtle Fibropapillomatosis. Phase II : Viral Pathogenesis and Development of Diagnostic Assays
Research conducted under this RWO from July 1, 1997 through June 30, 2000 has
provided important new information about the pathogenesis, virology, and
immunology of marine turtle fibropapillomatosis. In particular, we have provided
strong evidence for the association of a herpesvirus with fibropapillomatosis of the
green turtle,Chelonia mydas, and the loggerhead turtle, Caretta caretta, in Florida. In
addition we have provided new evidence for the absence of papillomaviruses from
sea turtle fibropapillomas. Although unsuccessful, important new attempts were made
to cultivate the FP-associated herpesvirus in vitro in collaboration with the National
Wildlife Health Center. During this period of time, we completed publication of the first
comprehensive description of the comparative pathology and pathogenesis of
experimentally induced and spontaneous fibropapillomas of green turtles (Chelonia
mydas). We initiated innovative studies on the persistence of a Chelonian
herpesviruses in the marine environment demonstrating for the first time that the
environmental survivability of Chelonian herpesviruses makes them real threats to
marine turtle health. Finally, we explored development of a serological assay for FP
using synthetic herpesvirus peptides and developed methodologies for detection of
antibodies to LETV [Iung-eye-trachea virus] a disease-associated herpesvirus of the
green turtle, Chelonia mydas.. This last initiative is ongoing and will further our efforts
to develop specific immunological assays for the FP-associated herpesvirus and FP. (17 page document
Numerical procedures for the calculation of the stresses in monocoques III : calculation of the bending moments in fuselage frames
This report deals with the calculation of the bending moments in and the distortions of fuselage rings upon which known concentrated and distributed loads are acting. In the procedure suggested, the ring is divided into a number of beams each having a constant radius of curvature. The forces and moments caused in the end sections of the beams by individual unit displacements of the end sections are listed in a table designated as the operations table in conformity with Southwell's nomenclature. The operations table and the external loads are equivalent to a set of linear equations. For their solution the following three procedures are presented: 1) Southwell's method of systematic relaxations. This is a step-by-step approximation procedure guided by the physical interpretation of the changes in the values of the unknown. 2) The growing unit procedure in which the individual beams are combined successively into beams of increasing length until finally the entire ring becomes a single beam. In each step of the procedure a set of not more than three simultaneous linear equations is solved. 3) Solution of the entire set of simultaneous equations by the methods of the matrix calculus. In order to demonstrate the manner in which the calculations may be carried out, the following numerical examples are worked out: 1) Curved beam with both its end sections rigidly fixed. The load is a concentrated force. 2) Egg-shape ring with symmetric concentrated loads. 3) Circular ring with antisymmetric concentrated loads and shear flow (torsion of the fuselage). 4) Same with V-braces incorporated in the ring. 5) Egg-shape ring with antisymmetric concentrated loads and shear flow (torsion of the fuselage). 6) Same with V-braces incorporated in the ring. The results of these calculations are checked, whenever possible, by calculations carried out according to known methods of analysis. The agreement is found to be good. The amount of work necessary for the solution of ring problems by the methods described in the present report is practically independent of the degree of redundancy of the structure. For this reason the methods are recommended for use particularly in problems of rings having one or more internal bracing elements
The effect of time constraint on anticipation, decision making, and option generation in complex and dynamic environments
Researchers interested in performance in complex and dynamic situations have focused on how individuals predict their opponent(s) potential courses of action (i.e., during assessment) and generate potential options about how to respond (i.e., during intervention). When generating predictive options, previous research supports the use of cognitive mechanisms that are consistent with long-term working memory (LTWM) theory (Ericsson and Kintsch in Phychol Rev 102(2):211â245, 1995; Ward et al. in J Cogn Eng Decis Mak 7:231â254, 2013). However, when generating options about how to respond, the extant research supports the use of the take-the-first (TTF) heuristic (Johnson and Raab in Organ Behav Hum Decis Process 91:215â229, 2003). While these models provide possible explanations about how options are generated in situ, often under time pressure, few researchers have tested the claims of these models experimentally by explicitly manipulating time pressure. The current research investigates the effect of time constraint on option-generation behavior during the assessment and intervention phases of decision making by employing a modified version of an established option-generation task in soccer. The results provide additional support for the use of LTWM mechanisms during assessment across both time conditions. During the intervention phase, option-generation behavior appeared consistent with TTF, but only in the non-time-constrained condition. Counter to our expectations, the implementation of time constraint resulted in a shift toward the use of LTWM-type mechanisms during the intervention phase. Modifications to the cognitive-process level descriptions of decision making during intervention are proposed, and implications for training during both phases of decision making are discussed
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