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Bat-borne zoonotic pathogens belonging to the family Paramxyoviridae, including Nipah and Hendra viruses, and the family Filoviridae, including Ebola and Marburg viruses, can cause severe disease and high mortality rates on spillover into human populations. Surveillance efforts for henipaviruses and filoviruses have been largely restricted to the Old World; however, recent studies suggest a potentially broader distribution for henipaviruses and filoviruses than previously recognized. In the current study, we screened for henipaviruses and filoviruses in New World bats collected across 4 locations in Trinidad near the coast of Venezuela. Bat tissue samples were screened using previously established reverse-transcription polymerase chain reaction assays. Serum were screened using a multiplex immunoassay to detect antibodies reactive with the envelope glycoprotein of viruses in the genus Henipavirus and the family Filoviridae. Serum samples were also screened by means of enzyme-linked immunosorbent assay for antibodies reactive with Nipah G and F glycoproteins. Of 84 serum samples, 28 were reactive with ≥1 henipavirus glycoprotein by ≥1 serological method, and 6 serum samples were reactive against ≥1 filovirus glycoproteins. These data provide evidence of potential circulation of viruses related to the henipaviruses and filoviruses in New World bats., (Published by Oxford University Press for the Infectious Diseases Society of America 2020.)

Hollow, cylindrical body plans, and obliquely striated muscles are characteristic of soft-bodied invertebrates, and both affect the biomechanics of movement in these diverse animals. We highlight two different aspects of functional heterogeneity in obliquely striated muscles, one driven by animal shape and size and the other by the intrinsic mechanical properties of the fibers. First, we show how a hollow, cylindrical shape in the mantle of cephalopod molluscs causes a significant difference in muscle strain (defined as the change in length divided by resting length) across the mantle wall, and describe the implications of such "transmural gradients of strain" for the length-tension relationship of the obliquely striated muscles that power movements in these animals. We show that transmural gradients of strain increase in magnitude as mantle wall proportions change during ontogeny, with the relatively thin mantle walls of newly hatched squid experiencing significantly smaller differences in strain than the thicker mantle walls of adults. Second, we describe how the length-tension relationship of obliquely striated mantle muscles varies with position to accommodate the transmural gradient of strain, with the result that circular muscle fibers near the inner and outer surfaces of the mantle are predicted to produce similar force during mantle contraction. The factors that affect the length-tension relationship in obliquely striated muscles are unknown, and thus we have not yet identified the mechanism(s) responsible for the transmural shift in the length-tension properties of the mantle circular fibers. We have, however, developed a mathematical model that predicts small changes in the oblique striation angle (which varies from 4 to 12° in adult squid) have a significant effect on the shape of the length-tension relationship, with lower angles predicted to result in a broader length-tension curve.

Squids encounter vastly different flow regimes throughout ontogeny as they undergo critical morphological changes to their two locomotive systems: the fins and jet. Squid hatchlings (paralarvae) operate at low and intermediate Reynolds numbers (Re) and typically have rounded bodies, small fins, and relatively large funnel apertures, whereas juveniles and adults operate at higher Re and generally have more streamlined bodies, larger fins, and relatively small funnel apertures. These morphological changes and varying flow conditions affect swimming performance in squids. To determine how swimming dynamics and propulsive efficiency change throughout ontogeny, digital particle image velocimetry (DPIV) and kinematic data were collected from an ontogenetic range of long-finned squid Doryteuthis pealeii and brief squid Lolliguncula brevis swimming in a holding chamber or water tunnel (Re = 20-20 000). Jet and fin wake bulk properties were quantified, and propulsive efficiency was computed based on measurements of impulse and excess kinetic energy in the wakes. Paralarvae relied predominantly on a vertically directed, high frequency, low velocity jet as they bobbed up and down in the water column. Although some spherical vortex rings were observed, most paralarval jets consisted of an elongated vortical region of variable length with no clear pinch-off of a vortex ring from the trailing tail component. Compared with paralarvae, juvenile and adult squid exhibited a more diverse range of swimming strategies, involving greater overall locomotive fin reliance and multiple fin and jet wake modes with better defined vortex rings. Despite greater locomotive flexibility, jet propulsive efficiency of juveniles/adults was significantly lower than that of paralarvae, even when juvenile/adults employed their highest efficiency jet mode involving the production of periodic isolated vortex rings with each jet pulse. When the fins were considered together with the jet for several juvenile/adult swimming sequences, overall propulsive efficiency increased, suggesting that fin contributions are important and should not be overlooked in analyses of the swimming performance of squids. The fins produced significant thrust and consistently had higher propulsive efficiency than did the jet. One particularly important area of future study is the determination of coordinated jet/fin wake modes that have the greatest impact on propulsive efficiency. Although such research would be technically challenging, requiring new, powerful, 3D approaches, it is necessary for a more comprehensive assessment of propulsive efficiency of the squid dual-mode locomotive system.

Administration of ammonium salts of perfluorooctanoate (PFOA) to rats results in peroxisome proliferation and benign liver tumors, events associated with activation of the nuclear receptor (NR) peroxisome proliferator-activated receptor-alpha (PPARalpha). Due to its fatty acid structure, PFOA may activate other NRs, such as PPARbeta, PPARgamma, liver X receptor (LXR), or retinoid X receptor (RXR). In this study, the activation of human, mouse, and rat PPARalpha, PPARbeta, PPARgamma, LXRbeta, and RXRalpha by PFOA (including its linear and branched isomers) and perfluorooctane sulfonate (PFOS) was investigated and compared to several structural classes of natural fatty acids and appropriate positive control ligands. An NR ligand-binding domain/Gal4 DNA-binding domain chimeric reporter system was used. Human, mouse, and rat PPARalpha were activated by PFOA isomers and PFOS. PPARbeta was less sensitive to the agents tested, with only PFOA affecting the mouse receptor. PFOA and PFOS also activated human, mouse, and rat PPARgamma, although the maximum induction of PPARgamma was much less than that seen with rosiglitazone, suggesting that PFOA and PFOS are partial agonists of this receptor. Neither LXRbeta nor the common heterodimerization partner RXRalpha was activated by PFOA in any species examined. Taken together, these data show that of the NRs studied, PPARalpha is the most likely target of PFOA and PFOS, although PPARgamma is also activated to some extent. Compared to naturally occurring long-chain fatty acids, e.g. linoleic and alpha-linolenic acids, these perfluorinated fatty acid analogs were more selective and less potent in their activation of the NRs.

Administration of phthalates is known to cause toxicity and liver cancer in rodents through the activation of peroxisome proliferator-activated receptors (PPARs), and the monoesters appear to be the active metabolites that function as ligands of PPARs. There is evidence that PPARs exhibit significant species differences in response to ligand activation. In this study, the activation of mouse and human PPARalpha, PPARbeta, and PPARgamma by a broad class of phthalate monoesters was investigated using a trans-activation assay, functional analysis of PPARalpha target gene expression, and a PPARgamma-mediated differentiation assay. These studies demonstrated a range in the ability of various phthalate monoesters to activate PPARalpha, with the mouse PPARalpha generally being activated at lower concentrations and exhibiting a greater response than human PPARalpha. Similarly, a range in the trans-activation of mouse PPARbeta by phthalate monoesters was also observed, but this effect was not found with human PPARbeta. A number of phthalate monoesters activated both mouse and human PPARgamma, with similar sensitivity being exhibited by both receptors. These studies show that the potency and efficacy of phthalate monoesters for the activation of PPARalpha and PPARgamma increase with increasing side-chain length. These studies also show that mouse PPARalpha and PPARbeta are generally activated at lower concentrations of phthalate monoesters than human PPARalpha and PPARbeta, and that both mouse and human PPARgamma exhibit similar sensitivity to phthalate monoesters. Lastly, there is a good relationship between the relative ability of phthalate monoesters to trans-activate PPARalpha and PPARgamma, and the relative induction of PPARalpha target gene mRNA and PPARgamma-mediated adipocyte differentiation, respectively.