Semliki Forest virus strongly reduces mosquito host defence signaling

The Alphavirus genus within the Togaviridae family contains several important mosquito-borne arboviruses. Other than the antiviral activity of RNAi, relatively little is known about alphavirus interactions with insect cell defences. Here we show that Semliki Forest virus (SFV) infection of Aedes albopictus-derived U4.4 mosquito cells reduces cellular gene expression. Activation prior to SFV infection of pathways involving STAT/IMD, but not Toll signaling reduced subsequent virus gene expression and RNA levels. These pathways are therefore not only able to mediate protective responses against bacteria but also arboviruses. However, SFV infection of mosquito cells did not result in activation of any of these pathways and suppressed their subsequent activation by other stimuli

A supplement containing multiple types of gluconeogenic substrates alters intake but not productivity of heat-stressed Afshari lambs

Citation: Mahjoubi, E., Amanlou, H., Yazdi, M. H., Aghaziarati, N., Noori, G. R., Vahl, C. I., . . . Baumgard, L. H. (2016). A supplement containing multiple types of gluconeogenic substrates alters intake but not productivity of heat-stressed Afshari lambs. Journal of Animal Science, 94(6), 2497-2505. doi:10.2527/jas2015-9697Thirty-two Afshari lambs were used in a completely randomized design with a 2 x 2 factorial arrangement of treatments to evaluate a nutritional supplement designed to provide multiple gluconeogenic precursors during heat stress (HS). Lambs were housed in thermal neutral (TN) conditions and fed ad libitum for 8 d to obtain covariate data (period 1 [P1]) for the subsequent experimental period (period 2 [P2]). During P2, which lasted 9 d, half of the lambs were subjected to HS and the other 16 lambs were maintained in TN conditions but pair fed (PFTN) to the HS lambs. Half of the lambs in each thermal regime were fed (top-dressed) 100 g/d of a feed supplement designed to provide gluconeogenic precursors (8 lambs in HS [heat stress with Glukosa {HSG}] and 8 lambs in PFTN [pair-fed thermal neutral with Glukosa]) and the other lambs in both thermal regimes were fed only the basal control diet (HS without Glukosa [HSC] and pair-fed thermal neutral without Glukosa). Heat stress decreased DMI (14%) and by design there were no differences between the thermal treatments, but HSG lambs had increased DMI (7.5%; P < 0.05) compared with the HSC lambs. Compared with PFTN lambs, rectal temperature and skin temperature at the rump, shoulder, and legs of HS lambs were increased (P < 0.05) at 0700 and 1400 h. Rectal temperature at 1400 h decreased for HSG lambs (0.15 +/- 0.03 degrees C; P < 0.05) compared with HSC lambs. Despite similar DMI between thermal treatments, ADG for HS and PFTN lambs in P2 was decreased 55 and 85%, respectively, compared with lambs in P1 (P < 0.01). Although the prefeeding glucose concentration was not affected by thermal treatment or diet, HSG lambs had increased postfeeding glucose concentration compared with HSC lambs (P < 0.05). In contrast to the glucose responses, circulating insulin was influenced only by thermal treatment; HS lambs had increased insulin concentration (P < 0.01) before feeding and decreased concentration (P < 0.05) after feeding compared with PFTN lambs. Heat-stressed lambs had decreased NEFA concentration before feeding (P < 0.01) but not after feeding relative to PFTN lambs. Although this nutritional strategy did not affect ADG, the lower rectal temperature in HSG lambs indicates that dietary inclusion of a mixture of glucogenic precursors can potentially benefit animal health during HS

Generalized squeezing operators, bipartite Wigner functions and entanglement via Wehrl's entropy functionals

We introduce a new class of unitary transformations based on the su(1,1) Lie algebra that generalizes, for certain particular representations of its generators, well-known squeezing transformations in quantum optics. To illustrate our results, we focus on the two-mode bosonic representation and show how the parametric amplifier model can be modified in order to generate such a generalized squeezing operator. Furthermore, we obtain a general expression for the bipartite Wigner function which allows us to identify two distinct sources of entanglement, here labelled by dynamical and kinematical entanglement. We also establish a quantitative estimate of entanglement for bipartite systems through some basic definitions of entropy functionals in continuous phase-space representations.Comment: 16 page

Influence of topography on tide propagation and amplification in semi-enclosed basins

An idealized model for tide propagation and amplification in semi-enclosed rectangular basins is presented, accounting for depth differences by a combination of longitudinal and lateral topographic steps. The basin geometry is formed by several adjacent compartments of identical width, each having either a uniform depth or two depths separated by a transverse topographic step. The problem is forced by an incoming Kelvin wave at the open end, while allowing waves to radiate outward. The solution in each compartment is written as the superposition of (semi)-analytical wave solutions in an infinite channel, individually satisfying the depth-averaged linear shallow water equations on the f plane, including bottom friction. A collocation technique is employed to satisfy continuity of elevation and flux across the longitudinal topographic steps between the compartments. The model results show that the tidal wave in shallow parts displays slower propagation, enhanced dissipation and amplified amplitudes. This reveals a resonance mechanism, occurring when\ud the length of the shallow end is roughly an odd multiple of the quarter Kelvin wavelength. Alternatively, for sufficiently wide basins, also Poincaré waves may become resonant. A transverse step implies different wavelengths of the incoming and reflected Kelvin wave, leading to increased amplitudes in shallow regions and a shift of amphidromic points in the direction of the deeper part. Including the shallow parts near the basin’s closed end (thus capturing the Kelvin resonance mechanism) is essential to reproduce semi-diurnal and diurnal\ud tide observations in the Gulf of California, the Adriatic Sea and the Persian Gulf

Gene silencing in tick cell lines using small interfering or long double-stranded RNA

Gene silencing by RNA interference (RNAi) is an important research tool in many areas of biology. To effectively harness the power of this technique in order to explore tick functional genomics and tick-microorganism interactions, optimised parameters for RNAi-mediated gene silencing in tick cells need to be established. Ten cell lines from four economically important ixodid tick genera (Amblyomma, Hyalomma, Ixodes and Rhipicephalus including the sub-species Boophilus) were used to examine key parameters including small interfering RNA (siRNA), double stranded RNA (dsRNA), transfection reagent and incubation time for silencing virus reporter and endogenous tick genes. Transfection reagents were essential for the uptake of siRNA whereas long dsRNA alone was taken up by most tick cell lines. Significant virus reporter protein knockdown was achieved using either siRNA or dsRNA in all the cell lines tested. Optimum conditions varied according to the cell line. Consistency between replicates and duration of incubation with dsRNA were addressed for two Ixodes scapularis cell lines; IDE8 supported more consistent and effective silencing of the endogenous gene subolesin than ISE6, and highly significant knockdown of the endogenous gene 2I1F6 in IDE8 cells was achieved within 48 h incubation with dsRNA. In summary, this study shows that gene silencing by RNAi in tick cell lines is generally more efficient with dsRNA than with siRNA but results vary between cell lines and optimal parameters need to be determined for each experimental system

Neutron diffraction study of stripe order in La(2)NiO(4+d) with d=2/15

We report a detailed neutron scattering study of the ordering of spins and holes in oxygen-doped La(2)NiO(4.133). The single-crystal sample exhibits the same oxygen-interstitial order but better defined charge-stripe order than that studied previously in crystals with d = 0.125. In particular, charge order is observed up to a temperature at least twice that of the magnetic transition, T_m = 110.5 K. On cooling through T_m, the wave vector \epsilon, equal to half the charge-stripe density within an NiO(2) layer, jumps discontinuously from 1/3 to 0.2944. It continues to decrease with further cooling, showing several lock-in transitions on the way down to low temperature. To explain the observed lock-ins, a model is proposed in which each charge stripe is centered on either a row of Ni or a row of O ions. The model is shown to be consistent with the l-dependence of the magnetic peak intensities and with the relative intensities of the higher-order magnetic satellites. Analysis of the latter also provides evidence that the magnetic domain walls (charge stripes) are relatively narrow. In combination with a recent study of magnetic-field-induced effects, we find that the charge stripes are all O-centered at T>T_m, with a shift towards Ni centering at T<T_m. Inferences concerning the competing interactions responsible for the the temperature dependence of \epsilon and the localization of charge within the stripes are discussed.Comment: ReVTeX, 17 2-col pages, 10 eps figs. embedded with psfig, submitted to Phys. Rev.

Glycerol-3-Phosphate Acyltransferase 1 Deficiency in ob/ob Mice Diminishes Hepatic Steatosis but Does Not Protect Against Insulin Resistance or Obesity

OBJECTIVEHepatic steatosis is strongly associated with insulin resistance, but a causal role has not been established. In ob/ob mice, sterol regulatory element binding protein 1 (SREBP1) mediates the induction of steatosis by upregulating target genes, including glycerol-3-phosphate acyltransferase-1 (Gpat1), which catalyzes the first and committed step in the pathway of glycerolipid synthesis. We asked whether ob/ob mice lacking Gpat1 would have reduced hepatic steatosis and improved insulin sensitivity.RESEARCH DESIGN AND METHODSHepatic lipids, insulin sensitivity, and hepatic insulin signaling were compared in lean (Lep+/?), lean-Gpat1−/−, ob/ob (Lepob/ob), and ob/ob-Gpat1−/− mice.RESULTSCompared with ob/ob mice, the lack of Gpat1 in ob/ob mice reduced hepatic triacylglycerol (TAG) and diacylglycerol (DAG) content 59 and 74%, respectively, but increased acyl-CoA levels. Despite the reduction in hepatic lipids, fasting glucose and insulin concentrations did not improve, and insulin tolerance remained impaired. In both ob/ob and ob/ob-Gpat1−/− mice, insulin resistance was accompanied by elevated hepatic protein kinase C-ε activation and blunted insulin-stimulated Akt activation.CONCLUSIONSThese results suggest that decreasing hepatic steatosis alone does not improve insulin resistance, and that factors other than increased hepatic DAG and TAG contribute to hepatic insulin resistance in this genetically obese model. They also show that the SREBP1-mediated induction of hepatic steatosis in ob/ob mice requires Gpat1

Phenoloxidase activity acts as a mosquito innate immune response against infection with semliki forest virus

Several components of the mosquito immune system including the RNA interference (RNAi), JAK/STAT, Toll and IMD pathways have previously been implicated in controlling arbovirus infections. In contrast, the role of the phenoloxidase (PO) cascade in mosquito antiviral immunity is unknown. Here we show that conditioned medium from the Aedes albopictus-derived U4.4 cell line contains a functional PO cascade, which is activated by the bacterium Escherichia coli and the arbovirus Semliki Forest virus (SFV) (Togaviridae; Alphavirus). Production of recombinant SFV expressing the PO cascade inhibitor Egf1.0 blocked PO activity in U4.4 cell- conditioned medium, which resulted in enhanced spread of SFV. Infection of adult female Aedes aegypti by feeding mosquitoes a bloodmeal containing Egf1.0-expressing SFV increased virus replication and mosquito mortality. Collectively, these results suggest the PO cascade of mosquitoes plays an important role in immune defence against arboviruses

Stringency of COVID-19 containment response policies and air quality changes: a global analysis across 1851 cities

The COVID-19 containment response policies (CRPs) had a major impact on air quality (AQ). These CRPs have been time-varying and location-specific. So far, despite having numerous studies on the effect of COVID-19 lockdown on AQ, a knowledge gap remains on the association between stringency of CRPs and AQ changes across the world, regions, nations, and cities. Here, we show that globally across 1851 cities (each more than 300000 people) in 149 countries, after controlling for the impacts of relevant covariates (e.g., meteorology), Sentinel-5P satellite-observed nitrogen dioxide (NO2) levels decreased by 4.9% (95% CI: 2.2, 7.6%) during lockdowns following stringent CRPs compared to pre-CRPs. The NO2 levels did not change significantly during moderate CRPs and even increased during mild CRPs by 2.3% (95% CI: 0.7, 4.0%), which was 6.8% (95% CI: 2.0, 12.0%) across Europe and Central Asia, possibly due to population avoidance of public transportation in favor of private transportation. Among 1768 cities implementing stringent CRPs, we observed the most NO2 reduction in more populated and polluted cities. Our results demonstrate that AQ improved when and where stringent COVID-19 CRPs were implemented, changed less under moderate CRPs, and even deteriorated under mild CRPs. These changes were location-, region-, and CRP-specific