The Leucocytic response of swine to stilbestrol and a progesterone-estradiol combination

This work was conducted in combination with the Regional Swine Breeding Laboratory, AHRD, ARS, USDA--P. [3].Digitized 2007 AES.Includes bibliographical references (page 15)

THE LIFESPAN OF CORPORA LUTEA INDUCED DURING THE LUTEAL PHASE OF THE ESTROUS CYCLE IN SWINE.

A more complete understanding of the mechanisms involved in the function and maintenance of the corpus luteum would be very useful in developing more effective methods of controlling the estrous cycle in farm animals. Various types and classes of experimental animals have been utilized in an effort to define the factors causing the persistence of the corpus luteum. In swine, several different experimental approaches have been made in an attempt to extend, experimentally, the functional lifespan of the corpus luteum in non-pregnant animals. Less frequently, attempts have been made to induce premature regression. In general, the procedures used to induce premature regression have not been effective when applied to the corpora lutea of cycling swine. For example, Sammelwitz et al. (1) reported that injected progesterone would cause luteal regression in pregnant swine but not in cycling swine

From Light Nuclei to Nuclear Matter. The Role of Relativity?

The success of non-relativistic quantum dynamics in accounting for the binding energies and spectra of light nuclei with masses up to A=10 raises the question whether the same dynamics applied to infinite nuclear matter agrees with the empirical saturation properties of large nuclei.The simple unambiguous relation between few-nucleon and many-nucleon Hamiltonians is directly related to the Galilean covariance of nonrelativistic dynamics. Relations between the irreducible unitary representations of the Galilei and Poincare groups indicate thatthe ``nonrelativistic'' nuclear Hamiltonians may provide sufficiently accurate approximations to Poincare invariant mass operators. In relativistic nuclear dynamics based on suitable Lagrangeans the intrinsic nucleon parity is an explicit, dynamically relevant, degree of freedom and the emphasis is on properties of nuclear matter. The success of this approach suggests the question how it might account for the spectral properties of light nuclei.Comment: conference proceedings "The 11th International Conference on Recent Progress in Many-Body Theories" to be published by World Scientifi

Fragmentation pathways of [Re₂(μ-OR)₃(CO)₆]– (R = H, Me) and ligand exchange reactions with oxygen donor ligands, investigated by electrospray mass spectrometry

The rhenium hydroxy and methoxy carbonyl complexes [Re₂(μOR)₃(CO)₆]⁻ (R = H or Me) have been studied by negative-ion electrospray mass spectrometry (ESMS). The complexes undergo facile exchange reactions with protic compounds, including alcohols and phenols. With dimethyl malonate, ester hydrolysis occurs giving carboxylate-containing complexes, and with H₂O₂ or ButOOH, oxidation to ReO₄⁻occurs. The feasibility and extent of these reactions can conveniently, rapidly, and unambiguously be determined by electrospray mass spectrometry, and is dependent on the acidity and steric bulk of the protic compound. The results also suggest that the complexes can be used as versatile starting materials for the synthesis of a wide range of analogous [Re₂(μ-OR)₃(CO)₆]⁻ complexes by simple reaction with an excess of the appropriate alcohol. By varying the applied cone voltage the fragmentation pathways have been investigated; the hydroxy complex undergoes dehydration followed by CO loss, whereas for the methoxy complex -hydride elimination (and CO loss) is observed, with confirmation provided by deuterium labelling studies. Under ESMS conditions, the neutral complexes [Re₂(μ-OR)₂(μ-dppf )(CO)₆] [R = H or Me; dppf = 1,1 -bis(diphenylphosphino)ferrocene] undergo substantial solvolysis and hydrolysis to give mainly mononuclear species; simple parent ions (e.g. [M + H]⁺) are not formed in appreciable abundance, probably due to the lack of an efficient ionisation pathway

AAA gunnermodel based on observer theory

The Luenberger observer theory is used to develop a predictive model of a gunner's tracking response in antiaircraft artillery systems. This model is composed of an observer, a feedback controller and a remnant element. An important feature of the model is that the structure is simple, hence a computer simulation requires only a short execution time. A parameter identification program based on the least squares curve fitting method and the Gauss Newton gradient algorithm is developed to determine the parameter values of the gunner model. Thus, a systematic procedure exists for identifying model parameters for a given antiaircraft tracking task. Model predictions of tracking errors are compared with human tracking data obtained from manned simulation experiments. Model predictions are in excellent agreement with the empirical data for several flyby and maneuvering target trajectories

Alteration of the estrous cycle of swine with exogenous pituitary gonadotrophins

Digitized 2007 AES.Includes bibliographical references (page 10)

Universality of residence-time distributions in non-adiabatic stochastic resonance

We present mathematically rigorous expressions for the residence-time and first-passage-time distributions of a periodically forced Brownian particle in a bistable potential. For a broad range of forcing frequencies and amplitudes, the distributions are close to periodically modulated exponential ones. Remarkably, the periodic modulations are governed by universal functions, depending on a single parameter related to the forcing period. The behaviour of the distributions and their moments is analysed, in particular in the low- and high-frequency limits.Comment: 8 pages, 1 figure New version includes distinction between first-passage-time and residence-time distribution

Imaginary companions in childhood: Relations to imagination skills and autobiographical memory in adults

The presence of a childhood imaginary companion (IC) has been proposed to reflect heightened imaginative abilities. This study hypothesized that adults who reported having a childhood IC would score higher on a task requiring the imaginative construction of visual scenes. Additionally, it was proposed that individuals who produced more vivid and detailed scenes would also report richer autobiographical memories, due to a shared reliance on imaginative abilities in construction and recollection. Sixty participants (20 with an IC), completed an adapted scene construction procedure and an autobiographical memory questionnaire. Participants reporting a childhood IC scored significantly higher on scene construction and rated themselves as more imaginative. Scene construction scores were also moderately related to the richness of autobiographical memories, although this was almost entirely due to scores on the thought/emotion/action component of scene construction. Autobiographical memory was unrelated to the presence of an IC. Implications for overlapping and dissociable aspects of imagination and memory are discussed