Provisional list of parasites occurring on Fundulus spp

In recent years interest in the utilization of fishes, particularly marine species, as experimental animals has increased. In the search for species amenable to this use, many investigators have chosen the hardy euryhaline species belonging to the genus Fundulus. In the course of holding these animals under restricted laboratory conditions, problems involving parasitization have developed. In the summer of 1964, workers at our Institute experienced great difficulty in maintaining Fundulus in captivity, and large numbers of experimental animals died. Examination of these fish revealed them to be heavily infested with monogenetic trematodes (mostly gyrodactylids, a few dactylogyrids). Inasmuch as severe cases of parasitism could well effect experimental results and render interpretation difficult, it is important that rnlationships between experimental animals and their parasites be recognized and dealt with. It is hoped that this provisional list of symbionts of the fundulid cyprinidonts will be of help in this regard. The following lists of parasites and bibliographic data have been compiled from monographic works, check-lists and various papers in the pertinent fields. Additional records from the researches of workers at this Institute are reported

BIOPHYSICAL SIMULATION IN SUPPORT OF CROP PRODUCTION DECISIONS: A CASE STUDY IN THE BLACKLANDS REGION OF TEXAS

Economic feasibility of Texas Blacklands corn production in relation to sorghum, wheat, and cotton is studied. Biophysical simulation generated yield data are integrated with an economic decision model using quadratic programming. Given the various scenarios analyzed, corn is economically feasible for the Blacklands. A crop mix of half corn and half cotton production is selected under risk neutrality with wheat entering if risk aversion is present. Corn and grain sorghum production are highly substitutable. Profit effects attributed to changing corn planting dates are more pronounced than profit changes resulting from altering corn population or maturity class.Crop Production/Industries,

Entropy and the driving force for the filling of carbon nanotubes with water

The spontaneous filling of hydrophobic carbon nanotubes (CNTs) by water observed both experimentally and from simulations is counterintuitive because confinement is generally expected to decrease both entropy and bonding, and remains largely unexplained. Here we report the entropy, enthalpy, and free energy extracted from molecular dynamics simulations of water confined in CNTs from 0.8 to 2.7-nm diameters. We find for all sizes that water inside the CNTs is more stable than in the bulk, but the nature of the favorable confinement of water changes dramatically with CNT diameter. Thus we find (i) an entropy (both rotational and translational) stabilized, vapor-like phase of water for small CNTs (0.8–1.0 nm), (ii) an enthalpy stabilized, ice-like phase for medium-sized CNTs (1.1–1.2 nm), and (iii) a bulk-like liquid phase for tubes larger than 1.4 nm, stabilized by the increased translational entropy as the waters sample a larger configurational space. Simulations with structureless coarse-grained water models further reveal that the observed free energies and sequence of transitions arise from the tetrahedral structure of liquid water. These results offer a broad theoretical basis for understanding water transport through CNTs and other nanostructures important in nanofluidics, nanofiltrations, and desalination

Monogenetic trematodes from the Southern Pacific Ocean Polyopisthocotyleids from the Australian fishes, the subfamily Polylabrinae and Microcotylinae

This eighth of a series of monogenetic trematodes from the Southern Pacific Ocean discusses two species of Monogenea from Australian waters. Polylabroides mylionis n. sp., from the gills of Mylio butcheri, is described. Neobivagina agonostomi (Sandars, 1945} Dillon and Hargis, 1965, from the gills of Aldrichett~ forsteri, is redescribed; a new locality record is reported for Neobivagina agonostomi

Monogeneans from the southern Pacific Ocean: Polyopisthocotyleids from the Australian fishes, the subfamily Microcotylinae

This seventh in a series of monogenetic trematodes from the Southern Pacific Ocean discusses nine species of Monogenea from Australian waters. Redescriptions are given for Microcotyle arripis Sandars, 1945, M. bassensis Murray, 1931, M. helotes Sandars, 1944, M. nemadactylus Dillon and Hargis, 1965, M. neozealanicus Dillon and Hargis, 1965, M. odacis Sandars, 1945, M. pentapodi Sandars, 1944, and M. temnodontis Sandars, 1945. New locality records are reported for all of the above. New host records are established for Microcotyle bassensis Murray, 1931 and M. neozealanicus Dillon and Hargis, 1965. Microtyle sp. from the gills of Acanthopagrus australis (Gunther) is reported

Monogeneans from the southern Pacific Ocean, Polyopisthocotyleids from the Australian fishes, the subfamily Polylabrinae and Microcotylinae

This sixth of a series on monogenetic trematodes from the Southern Pacific Ocean discusses five species of Monogenea from Australian waters. Polylabris carnivonensis n. sp., from the gills of Leiognathus fasciatus, and Polylabris sigani no. sp., from the gills of Siganus ormin, are described. Polylabris sillaginae (Woolcock, 1936) n. comb and Gonoplasius carangis Sandars, 1944 are redescribed. In order that comparisons can be made between Australian and New Zealand populations, Kahawaia truttae (Dillon and Hargis, 1965) Lebedev, 1969 is briefly I described

Origin of adiabatic and non-adiabatic spin transfer torques in current-driven magnetic domain wall motion

A consistent theory to describe the correlated dynamics of quantum mechanical itinerant spins and semiclassical local magnetization is given. We consider the itinerant spins as quantum mechanical operators, whereas local moments are considered within classical Lagrangian formalism. By appropriately treating fluctuation space spanned by basis functions, including a zero-mode wave function, we construct coupled equations of motion for the collective coordinate of the center-of-mass motion and the localized zero-mode coordinate perpendicular to the domain wall plane. By solving them, we demonstrate that the correlated dynamics is understood through a hierarchy of two time scales: Boltzmann relaxation time when a non-adiabatic part of the spin-transfer torque appears, and Gilbert damping time when adiabatic part comes up.Comment: 4 pages, 2 figure

DNA Instability at Chromosomal Fragile Sites in Cancer

Human chromosomal fragile sites are specific genomic regions which exhibit gaps or breaks on metaphase chromosomes following conditions of partial replication stress. Fragile sites often coincide with genes that are frequently rearranged or deleted in human cancers, with over half of cancer-specific translocations containing breakpoints within fragile sites. But until recently, little direct evidence existed linking fragile site breakage to the formation of cancer-causing chromosomal aberrations. Studies have revealed that DNA breakage at fragile sites can induce formation of RET/PTC rearrangements, and deletions within the FHIT gene, resembling those observed in human tumors. These findings demonstrate the important role of fragile sites in cancer development, suggesting that a better understanding of the molecular basis of fragile site instability is crucial to insights in carcinogenesis. It is hypothesized that under conditions of replication stress, stable secondary structures form at fragile sites and stall replication fork progress, ultimately resulting in DNA breaks. A recent study examining an FRA16B fragment confirmed the formation of secondary structure and DNA polymerase stalling within this sequence in vitro, as well as reduced replication efficiency and increased instability in human cells. Polymerase stalling during synthesis of FRA16D has also been demonstrated. The ATR DNA damage checkpoint pathway plays a critical role in maintaining stability at fragile sites. Recent findings have confirmed binding of the ATR protein to three regions of FRA3B under conditions of mild replication stress. This review will discuss recent advances made in understanding the role and mechanism of fragile sites in cancer development

Kolmogorov Similarity Hypotheses for Scalar Fields: Sampling Intermittent Turbulent Mixing in the Ocean and Galaxy

Kolmogorov's three universal similarity hypotheses are extrapolated to describe scalar fields like temperature mixed by turbulence. By the analogous Kolmogorov third hypothesis for scalars, temperature dissipation rates chi averaged over lengths r > L_K should be lognormally distributed with intermittency factors I that increase with increasing turbulence energy length scales L_O as I_chi-r = m_T ln(L_O/r). Tests of Kolmogorovian velocity and scalar universal similarity hypotheses for very large ranges of turbulence length and time scales are provided by data from the ocean and the Galactic interstellar medium. The universal constant for turbulent mixing intermittency m_T is estimated from oceanic data to be 0.44+-0.01, which is remarkably close to estimates for Kolmogorov's turbulence intermittency constant m_u of 0.45+-0.05 from Galactic as well as atmospheric data. Extreme intermittency complicates the oceanic sampling problem, and may lead to quantitative and qualitative undersampling errors in estimates of mean oceanic dissipation rates and fluxes. Intermittency of turbulence and mixing in the interstellar medium may be a factor in the formation of stars.Comment: 23 pages original of Proc. Roy. Soc. article, 8 figures; in "Turbulence and Stochastic Processes: Kolmogorov's ideas 50 years on", London The Royal Society, 1991, J.C.R. Hunt, O.M. Phillips, D. Williams Eds., pages 1-240, vol. 434 (no. 1890) Proc. Roy. Soc. Lond. A, PDF fil