Prevalence of infectious diseases in feral cats in Northern Florida

Objectives of this study were to determine prevalence of infection in feral cats in Northern Florida with a select group of infectious organisms and to determine risk factors for infection. Blood samples or sera from 553 cats were tested with a panel of antibody, antigen or PCR assays. Male cats were at higher risk for FIV, Mycoplasma haemofelis, and M. haemominutum. Infection with either FeLV or FIV was associated with increased risk for coinfection with the other retrovirus, M. haemofelis, or M. haemominutum. Bartonella henselae had the highest prevalence and was the only organism that did not have any associated risk for coinfection with other organisms. Feral cats in this study had similar or lower prevalence rates of infections than those published for pet cats in the United States. Thus, feral cats assessed in this study appear to be of no greater risk to human beings or other cats than pet cats.     

A Redox Fuel Cell That Operates with Methane as Fuel at 120{degrees}C

Platinum black efficiently catalyzes the oxidation of methane by iron(III) to generate carbon dioxide and eight equivalents of iron(II) in solutions of sulfuric acid in water. The rate of oxidation increases over 4 hours to reach approximately 4.83 x 10(-2) moles of iron(II) per gram atom of surface platinum per second. A redox fuel cell was assembled that used this reaction in a liquid reformer to generate soluble reducing equivalents of iron(II) from methane, which was electrochemically oxidized to iron(III) in the cell. A vanadium(V)-(IV)-nitric acid-O(2) redox system catalyzed the electrochemical reduction of O(2). The open-circuit voltage of the cell was 0.48 volt, and the maximum power output of the cell was 8.1 milliwatts per cubic centimeter of graphite felt electrode.     

Sensitivity analysis of sea scallop (Placopecten magellanicus) larvae trajectories to hydrodynamic model configuration on Georges Bank and adjacent coastal regions

The previous larval-trajectory modeling studies on Georges Bank were assessed through process-oriented Lagrangian-tracking comparison experiments using the high-resolution Gulf of Maine/Georges Bank Finite-Volume Coastal Ocean Model (GOM-FVCOM). The results indicate that in a strong nonlinear system such as Georges Bank, the passive tracer movement is driven by a fully three-dimensional Lagrangian flow field that varies in space and time due to large tidal excursion and steep bottom topography. The particle-tracking methods developed based on the assumption of weak nonlinearity of the flow field are not applicable to Georges Bank. The results of previous larval transport studies driven by circulation fields constructed under the weak-nonlinearity assumption need to be interpreted with caution. In the present work, the influence of model physical setups on sea scallop larval dispersal and settlement on Georges Bank and adjacent shelf regions is examined. Distinct differences in the spatial distribution of the passive larvae predicted by the model under various physical conditions suggest that a fully nonlinear model driven by realistic spatially and temporally varying forcing should be employed for Lagrangian-based studies of fishery population dynamics on Georges Bank.     

The role of B‐type esterases in conferring insecticide resistance in the tobacco whitefly,Bemisia tabaci (Genn)

Separation of non‐specific esterases on electrophoretic gels has played a key role in distinguishing between races or biotypes of the tobacco whitefly, Bemisia tabaci. One intensively staining esterase in particular (termed E_0.14) has assumed significance as a diagnostic of B‐type whiteflies (aka Bemisia argentifolii), despite any knowledge of its biological function. In this study, a whitefly strain (B‐Null) homozygous for a null allele at the E_0.14 locus that had been isolated from a B‐type population was used to demonstrate a significant role for E_0.14 in resistance of B‐type populations to pyrethroids but not to organophosphates (OPs). Bioassays with pyrethroids, following pre‐treatment with sub‐lethal doses of the OP profenofos (to inhibit esterase activity), coupled with metabolism studies with radiolabelled permethrin, supported the conclusion that pyrethroid resistance in a range of B‐type strains expressing E_0.14 was primarily due to increased ester hydrolysis. In the same strains, OP resistance appeared to be predominantly conferred by a modification to the target‐site enzyme acetylcholinesterase. © 2000 Society of Chemical Industry     

Transient expression shows ligand gating and allosteric potentiation of GABAA receptor subunits

Human gamma-aminobutyric acid A (GABAA) receptor subunits were expressed transiently in cultured mammalian cells. This expression system allows the simultaneous characterization of ligand-gated ion channels by electrophysiology and by pharmacology. Thus, coexpression of the alpha and beta subunits of the GABAA receptor generated GABA-gated chloride channels and binding sites for GABAA receptor ligands. Channels consisting of only alpha or beta subunits could also be detected. These homomeric channels formed with reduced efficiencies compared to the heteromeric receptors. Both of these homomeric GABA-responsive channels were potentiated by barbiturate, indicating that sites for both ligand-gating and allosteric potentiation are present on receptors assembled from either subunit.     

Natural hybridization between two sibling species of Anolis lizards: chromosome cytology

The Lesser Antillean lizards Anolis trinitatis and Anolis aenous were both apparently introduced to Trinidad where they are hybridizing. The parental species have 36 and 34 chromosomes, respectively. Hybrids have 35 chromosomes. Meiosis in hybrids is abnormal. There is an accumulation of cells at metaphase I, and poor homolog pairing, characterized by a low frequency of chiasmata and numerous univalents.     

A comparison of the F-test, Friedman’s test, and several aligned rank tests for the analysis of randomized complete blocks

Several tests for randomized complete block designs are compared, including the F-test, Friedman’s test, and a few aligned rank tests. An additive model was used in this simulation study with random errors that were generated independently from one of nine distributions. These distributions included the uniform, normal, double exponential, and six skewed distributions from the generalized lambda family. The simulations showed that Friedman’s test has low power compared with the aligned rank tests if the number of treatments does not exceed six. A new aligned rank F-test is proposed that maintains its significance level and has relatively high power. The simulations also showed that the proposed aligned rank test has higher power than the F-test for the double exponential and the skewed distributions if there is a large number of experimental units. If the number of experimental units exceeds 30, the proposed aligned rank test is recommended for skewed or long-tailed distributions. If the number of experimental units does not exceed 30, the normal theory F-test is recommended.