Characterization of anti-tumor immunity in oyster toadfish (Opsanus tau), and the effects of 7,12 -dimethylbenz(A)anthracene on this immune response

Cell-mediated lysis of cultured tumor target cells by nonspecific cytotoxic cells (NCC) was examined in the oyster toadfish (Opsanus tau), an estuarine teleost. NCC activity was evaluated in cells taken from the head kidney, peripheral blood, spleen and peritoneal cavity. NCC activity was a property of plastic nonadherent cells which lacked phagocytic activity, indicating that in terms of their functional capacity, the cells which mediate nonspecific cytoxic immune responses in oyster toadfish do not appear to be monocytes or macrophages. However, light and electron microscopic examination of these cells revealed that morphologically, they resemble monocytes and macrophages. A new technique to assess in vitro phagocytic function of fish macrophages is described. This assay involves the spectrophotometric measurement of congo red-stained yeast cells that have been phagocytized by macrophages. The assay is simple, rapid and reproducible. Furthermore, it is less subjective than previously described methods that employ microscopic examination of cells. Using this technique with oyster toadfish, phagocytosis of yeast cells was found to increase with time, reaching a maximum between 60 and 90 minutes (as determined by absorbance at 510 nm). Sampling sites selected for this field investigation had a sediment-bound polycyclic aromatic hydrocarbon (PAH) concentration gradient of 55 ppb to 96,000 ppb total PAH. Results of this study suggest that varying levels of PAH contamination did not lead to significant between-site differences in terms of simple ability of oyster toadfish macrophages to phagocytize foreign particles. This technique has been used in studies designed to characterize the functioning of oyster toadfish NCC and in toxicological investigations comparing the effects of PAH and NCC and macrophage function in oyster toadfish. Studies were undertaken to determine the effect of the chemical carcinogen 7,12-dimethylbenz (a) anthracene (DMBA) on the function of oyster toadfish peritoneal nonspecific cytotoxic cells (NCC) and macrophages. The functioning of these two cell populations was assessed in terms of their ability to lyse cultured tumor target cells and to phagocytize yeast cells, respectively. In a time-course study, the effects of DMBA on NCC activity were found to be highly persistent. Following a single intraperitoneal injection of 10 mg/kg, NCC activity was again virtually eliminated, and did not recover throughout the 28 days of the exposure study. (Abstract shortened by UMI.)

Regulation of Rabbit Testicular Capsular Motility: Prostaglandins, Sex Steroids, and Sympathomimetic Agents

Smooth-muscle active compounds were extracted from rat and rabbit testicular homogenates, and from bathing media of rabbit testicular capsular preparations and were tentatively characterized as prostaglandins. The endogenous prostaglandins were responsible for spontaneous testicular capsular contractions in vitro, but were not solely responsible for spontaneous testicular capsular motility in vivo. In this respect, significantly greater concentrations of prostaglandins were extracted from bathing media from spontaneously contracting capsules in vitro than from inactive capsules in vitro or spontaneously contracting capsules in vivo. No significant difference was observed in the amount of prostaglandin extracted from the bathing media of inactive in vitro and spontaneously active in vivo preparations. Various sex steroids (progesterone, testosterone, androstenedione, 17 α-hydroxyprogesterone, 5α-androstan-17 β-ol-3-one, and pregnenolone) inhibited spontaneous or prostaglandin-induced contractions in vitro and contractions potentiated by serotonin or acetylcholine, but the steroids did not inhibit spontaneous in vivo capsular motility or capsular motility generated by epinephrine in vitro. In this respect, α - and β-adrenergic receptors were present in rabbit testicular capsules, and α-adrenergic blocking agents inhibited spontaneously contracting in vivo capsules suggesting that sympathetic nervous innervation may regulate testicular motility. Log dose-response curves for the effect of prostaglandin E1, E2, F1α, F2α and epinephrine on in vitro rabbit testicular capsules were determined, log dose-response curves for prostaglandin E1, F2α, and epinephrine indicate that they are equivalent for both in vivo and in vitro preparations. All of these compounds generated stimulatory responses, but prostaglandin E1 and E2 were inhibitory at higher concentrations. The data suggested that the inhibitory response of the capsule to higher concentrations of prostaglandin E1 and E2 were mediated by cyclic AMP. Theophylline (a phosphodiesterase inhibitor), isoproterenol (a β-adrenergic agonist), and cyclic AMP inhibited testicular capsular motility. Moreover, subthreshold concentrations of cyclic AMP potentiated the inhibitory response to PGE

An Electrophysiological Study of the Oral Plate Sensory Organs of the Honey Bee (\u3cem\u3eApis mellifera\u3c/em\u3e L.)

The oral plate sense organs of the honey bee, Apis mellifera L. , have been investigated employing an electrophysiological technique which allows simultaneous stimulation and recording. The results of the study present evidence that the four bipolar sense cells innervating the sensory papillae on the oral surface of the hypopharynx are chemoreceptors. The sensory papillae respond to cations, glucose, water, and amino acids. Evidence for the absence of a mechanosensory cell is presented. The data concerning the sensory structures agree with the current theories of chemoreception

Quiet engine program flight engine design study

The results are presented of a preliminary flight engine design study based on the Quiet Engine Program high-bypass, low-noise turbofan engines. Engine configurations, weight, noise characteristics, and performance over a range of flight conditions typical of a subsonic transport aircraft were considered. High and low tip speed engines in various acoustically treated nacelle configurations were included

Communicating the Value of Ergonomics to Management – Part 2: Ergonomics ROI Case Study Applications

More than ever, human factors engineers and ergonomists need to justify our practice’s value to management. How can we effectively communicate with management? How should we present a Return on Investment (ROI) that leadership will find useful that addresses company profits, cost savings, productivity, first time quality, and turnover? What else does management care about other than ROI? This second panel in a two panel series will specifically highlight case studies in which presenters give examples of situations in which ROI for ergonomics was investigated from a business value. The session will start with four case study lectures followed by a panel discussion led by the moderators. The audience will be encouraged to participate with their own questions and comments

Growing Degree Days Predictions for Corn and Sorghum Development and Some Applications to Crop Production in Nebraska

The concept of growing degree days (GDD) originated with observations by Reamur (1735) that plant development is more closely related to the temperature accumulated to a given stage than with time alone. It was not until nearly 200 years later, however, that Merriam (1894), Livingston (1916) and Klages (1942) began to use temperature accumulations in plant distribution studies and in crop geography. In the early 1950\u27s, a system involving growing degree days became widely used in the canning industry to schedule plantings and thus control time of harvest of rapidly maturing vegetables. This system provided a more precise control of both quantity and maturity of produce delivered for processing. It had a profound effect on processing efficiency and the cost and quality of canned vegetables, particularly peas and sweet corn. This study concerns GDD requirement for the series of consecutive phenological stages of field corn (Zea mays L.) and grain sorghum (Sorghum bicolor (L.) Moench) from emergence to physiological maturity. Such data are important for crop management decisions throughout the growing season

The Bravyi-Kitaev transformation for quantum computation of electronic structure

Quantum simulation is an important application of future quantum computers with applications in quantum chemistry, condensed matter, and beyond. Quantum simulation of fermionic systems presents a specific challenge. The Jordan-Wigner transformation allows for representation of a fermionic operator by O(n) qubit operations. Here we develop an alternative method of simulating fermions with qubits, first proposed by Bravyi and Kitaev [S. B. Bravyi, A.Yu. Kitaev, Annals of Physics 298, 210-226 (2002)], that reduces the simulation cost to O(log n) qubit operations for one fermionic operation. We apply this new Bravyi-Kitaev transformation to the task of simulating quantum chemical Hamiltonians, and give a detailed example for the simplest possible case of molecular hydrogen in a minimal basis. We show that the quantum circuit for simulating a single Trotter time-step of the Bravyi-Kitaev derived Hamiltonian for H2 requires fewer gate applications than the equivalent circuit derived from the Jordan-Wigner transformation. Since the scaling of the Bravyi-Kitaev method is asymptotically better than the Jordan-Wigner method, this result for molecular hydrogen in a minimal basis demonstrates the superior efficiency of the Bravyi-Kitaev method for all quantum computations of electronic structure

Pole structure of the Hamiltonian ζ\zeta-function for a singular potential

We study the pole structure of the $\zeta$-function associated to the Hamiltonian $H$ of a quantum mechanical particle living in the half-line $\mathbf{R}^+$, subject to the singular potential $g x^{-2}+x^2$. We show that $H$ admits nontrivial self-adjoint extensions (SAE) in a given range of values of the parameter $g$. The $\zeta$-functions of these operators present poles which depend on $g$ and, in general, do not coincide with half an integer (they can even be irrational). The corresponding residues depend on the SAE considered.Comment: 12 pages, 1 figure, RevTeX. References added. Version to appear in Jour. Phys. A: Math. Ge