De Novo synthesis of VP16 coordinates the exit from HSV latency in vivo

The mechanism controlling the exit from herpes simplex virus latency (HSV) is of central importance to recurrent disease and transmission of infection, yet interactions between host and viral functions that govern this process remain unclear. The cascade of HSV gene transcription is initiated by the multifunctional virion protein VP16, which is expressed late in the viral replication cycle. Currently, it is widely accepted that VP16 transactivating function is not involved in the exit from latency. Utilizing the mouse ocular model of HSV pathogenesis together with genetically engineered viral mutants and assays to quantify latency and the exit from latency at the single neuron level, we show that in vivo (i) the VP16 promoter confers distinct regulation critical for viral replication in the trigeminal ganglion (TG) during the acute phase of infection and (ii) the transactivation function of VP16 (VP16TF) is uniquely required for the exit from latency. TG neurons latently infected with the VP16TF mutant in 1814 do not express detectable viral proteins following stress, whereas viruses with mutations in the other major viral transcription regulators ICP0 and ICP4 do exit the latent state. Analysis of a VP16 promoter/reporter mutant in the background of in 1814 demonstrates that the VP16 promoter is activated in latently infected neurons following stress in the absence of other viral proteins. These findings support the novel hypothesis that de novo expression of VP16 regulates entry into the lytic program in neurons at all phases of the viral life cycle. HSV reactivation from latency conforms to a model in which stochastic derepression of the VP16 promoter and expression of VP16 initiates entry into the lytic cycl

Deaf and hearing children's picture naming Impact of age of acquisition and language modality on representational gesture

Stefanini, Bello, Caselli, Iverson, & Volterra (2009) reported that Italian 24-36 month old children use a high proportion of representational gestures to accompany their spoken responses when labelling pictures. The two studies reported here used the same naming task with (1) typically developing 24-46-month-old hearing children acquiring English and (2) 24-63-month-old deaf children of deaf and hearing parents acquiring British Sign Language (BSL) and spoken English. In Study 1 children scored within the range of correct spoken responses previously reported, but produced very few representational gestures. However, when they did gesture, they expressed the same action meanings as reported in previous research. The action bias was also observed in deaf children of hearing parents in Study 2, who labelled pictures with signs, spoken words and gestures. The deaf group with deaf parents used BSL almost exclusively with few additional gestures. The function of representational gestures in spoken and signed vocabulary development is considered in relation to differences between native and non-native sign language acquisition

Cell-Fate Choice in Dictyostelium: Intrinsic Biases Modulate Sensitivity to DIF Signaling

AbstractCell fate in Dictyostelium development depends on intrinsic differences between cells, dating from their growth period, and on cell interactions occurring during development. We have sought for a mechanism linking these two influences on cell fate. First, we confirmed earlier work showing that the vegetative differences are biases, not commitments, since cells that are stalky-biased when developed with one partner are sporey with another. Then we tested the idea that these biases operate by modulating the sensitivity of cells to the signals controlling cell fate during development. Cells grown without glucose are stalky-biased when developed with cells grown with glucose. We find, using monolayer culture conditions, that they are more sensitive to each of the stalk-inducing signals, DIFs 1–3. Mixing experiments show that this bias is a cell-intrinsic property. Cells initiating development early in the cell cycle are stalky compared to those initiating development later in the cycle. Likewise, they are more sensitive to DIF-1. Assays of standard markers for prestalk and prespore cell differentiation reveal similar differences in DIF-1 sensitivity between biased cells; DIF-1 dechlorinase (an early prestalk cell marker enzyme) behaves in a consistent manner. We propose that cell-fate biases are manifest as differences in sensitivity to DIF

Multi-end functionalised polymer additives synthesised by living anionic polymerisation-the impact of additive molecular structure upon surface properties

Numerous applications require specific properties at polymer surfaces that differ from the bulk. Herein we describe the novel synthesis of a series of multi-end functionalised poly(styrene) and poly(isoprene) additives carrying 1 to 3 fluoroalkyl (CF) groups. The additives were prepared by endcapping the living chain ends of polymers prepared via living anionic polymerisation. The resulting polymers have been used as additives to render the surface of polymer films hydrophobic/lipophobic and we have characterised these polymer films using static contact angle measurements with water as the contact fluid. We have found that the additive molecular weight, the number of CF groups, additive concentration and annealing conditions have a significant impact upon the resulting surface properties. Increasing the additive concentration and/or number of CF groups resulted in higher contact angles whereas increasing the molecular weight of additive reduced contact angles and surface hydrophobicity. It has been discovered that these additives undergo rapid adsorption to the surface of a thin film in the time taken to produce the film by spin coating and the result is significantly enhanced surface properties. Annealing polystyrene films above the glass transition temperature revealed some interesting behaviour in so much that it demonstrated that on many occasions it is preferable to anneal films containing very small quantities of additive rather than to simply add greater quantities of additive. In addition to contact angles measurements, Rutherford backscattering (RBS) analysis has been carried out on examples of modified poly(isoprene) films to quantitatively analyse the effect of additive molecular weight and number of fluoroalkyl groups on the near surface elemental composition of the modified thin films and confirming the relationship (described above) between these additive molecular parameters and surface adsorption. Finally, we have described a model which compares the behaviour of the additives in thin films to surfactants in solution

The influence of sense-contingent argument structure frequencies on ambiguity resolution in aphasia

Verbs with multiple senses can show varying argument structure frequencies, depending on the underlying sense. When acknowledge is used to mean ‘recognise’, it takes a direct object (DO), but when it is used to mean ‘admit’ it prefers a sentence complement (SC). The purpose of this study was to investigate whether people with aphasia (PWA) can exploit such meaning-structure probabilities during the reading of temporarily ambiguous sentences, as demonstrated for neurologically healthy individuals (NHI) in a self-paced reading study (Hare et al., 2003). Eleven people with mild or moderate aphasia and eleven neurologically healthy control participants read sentences while their eyes were tracked. Using adapted materials from the study by Hare et al., target sentences containing an SC structure (e.g. He acknowledged (that) his friends would probably help him a lot) were presented following a context prime that biased either a direct object (DO-bias) or sentence complement (SC-bias) reading of the verbs. Half of the stimuli sentences did not contain that so made the post verbal noun phrase (his friends) structurally ambiguous. Both groups of participants were influenced by structural ambiguity as well as by the context bias, indicating that PWA can, like NHI, use their knowledge of a verb’s sense-based argument structure frequency during online sentence reading. However, the individuals with aphasia showed delayed reading patterns and some individual differences in their sensitivity to context and ambiguity cues. These differences compared to the NHI may contribute to difficulties in sentence comprehension in aphasia

A comparison of forage yield and quality in a simulated graze-out for twelve varieties of hard red and white winter wheat

Six hard white winter wheat varieties (Burchett, Lakin, NuFrontier, NuHills, Nu- Horizon, and Trego) and six hard red winter wheat varieties (2137, Jagalene, Jagger, OK101, Stanton, and Thunderbolt) were planted in two southwestern Kansas counties, Clark and Stanton, to compare simulated graze-out forage yield and quality. Four replicated plots were planted in September 2003 for each variety at each location. Forage samples were collect from each plot during December 2003, March 2004, and April or May 2004. Dry matter content, dry matter yield, crude protein, acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrients (TDN), net energy (NEm, NEg), relative feed value (RFV), and nitrate nitrogen were determined. Significant location-by-variety interactions were observed for most factors. Although significant differences in crude protein and energy were detected, it is unlikely that the performance of stock cattle would differ when grazing each of the varieties because the lowest crude protein concentration would support excellent gain, and because the differences in energy were relatively small

Gavestinel does not improve outcome after acute intracerebral hemorrhage: an analysis from the GAIN International and GAIN Americas studies

<p><b>Background and Purpose:</b> Glycine Antagonist in Neuroprotection (GAIN) International and GAIN Americas trials were prospectively designed, randomized, placebo-controlled trials of gavestinel, a glycine-site antagonist and putative neuroprotectant drug administered within 6 hours of suspected ischemic or hemorrhagic stroke. Both trials reported that gavestinel was ineffective in ischemic stroke. This analysis reports the results in those with primary intracerebral hemorrhage.</p> <p><b>Methods:</b> The primary hypothesis was that gavestinel treatment did not alter outcome, measured at 3 months by the Barthel Index (BI), from acute intracerebral hemorrhage, based on pooled results from both trials. The BI scores were divided into 3 groups: 95 to 100 (independent), 60 to 90 (assisted independence), and 0 to 55 (dependent) or dead.</p> <p><b>Results:</b> In total, 3450 patients were randomized in GAIN International (N=1804) and GAIN Americas (N=1646). Of these, 571 were ultimately identified to have spontaneous intracerebral hematoma on baseline head computerized tomography scan. The difference in distribution of trichotomized BI scores at 3 months between gavestinel and placebo was not statistically significant (P=0.09). Serious adverse events were reported at similar rates in the 2 treatment groups.</p> <p><b>Conclusions:</b> These observations from the combined GAIN International and GAIN Americas trials suggest that gavestinel is not of substantial benefit or harm to patients with primary intracerebral hemorrhage. These findings are similar to results previously reported in patients with ischemic stroke.</p&gt

Random Mating in the Face of Balancing Selection at the Major Histocompatibility Complex Class I in Song Sparrows (Melospiza melodia)

The major histocompatibility complex (MHC) is a large group of genes encoding cell-surface proteins that recognize and bind pathogens to initiate an adaptive immune response. MHC loci experience intense pathogen-mediated selection which may be directional, where specific alleles provide the best disease protection, or balancing, where rare alleles or diverse combinations are most protective. However, balancing selection (specifically heterozygote advantage) is more common and often accompanied by disassortative mating. I sought to use genetic and behavioural information to evaluate whether balancing selection and disassortative mating occur at MHC class I (MHCI) in a population of song sparrows (Melospiza melodia). Despite evidence of balancing selection (high ratios of nonsynonymous to synonymous sequence variation and trans-species polymorphisms), the genetic distance between social mates was no different than expected under random mating. This may suggest a low impact of MHCI diversity on lifetime reproductive success, or an inability to discern MHCI genotype

Synthesis and characterisation of end-functionalised poly(N-vinylpyrrolidone) additives by reversible addition–fragmentation transfer polymerisation

We describe herein the synthesis of a series of multi-end functionalized poly(N-vinyl pyrrolidone) (PVP) additives bearing two or three C8F17 fluoroalkyl (CF) groups, designed as additives to modify surface properties. The PVP additives were prepared by reversible addition–fragmentation transfer (RAFT) polymerization, with end functionality imparted via the use of CF functionalized chain transfer agents (CTAs). The resulting PVP additives, when used in modest quantities dispersed in thin films of an unmodified PVP matrix significantly reduce the surface energy, rendering their surfaces more hydrophobic and lipophobic. This is achieved by virtue of the low surface energy of the pendant C8F17 end groups which cause the additive to spontaneously surface segregate during the spin coating process. The resulting thin films have been characterized by static contact angle measurements using dodecane as the contact fluid, and the impact of additive molecular weight, matrix molecular weight, the number of CF groups and additive concentration upon surface properties is reported herein. Significant increases in contact angle were observed with increasing additive concentration, up to a critical aggregation concentration (CAC). Increasing the number of CF groups (from 2 to 3); reducing additive molecular weight or increasing the matrix molecular weight, resulted in increased contact angles and hence surface lipophobicity. Rutherford backscattering (RBS) analysis was performed on films containing varying concentrations of additive, in order to quantitatively measure the near-surface fluorine concentration of these films. The results of these experiments were in excellent agreement with those obtained by contact angle analysis, confirming the surface activity and low surface energy of the additives

Eigenvector perturbation methodology for uncertainty quantification of turbulence models

Reynolds-averaged Navier-Stokes (RANS) models are the primary numerical recourse to investigate complex engineering turbulent flows in industrial applications. However, to establish RANS models as reliable design tools, it is essential to provide estimates for the uncertainty in their predictions. In the recent past, an uncertainty estimation framework relying on eigenvalue and eigenvector perturbations to the modeled Reynolds stress tensor has been widely applied with satisfactory results. However, the methodology for the eigenvector perturbations is not well established. Evaluations using only eigenvalue perturbations do not provide comprehensive estimates of model form uncertainty, especially in flows with streamline curvature, recirculation, or flow separation. In this article, we outline a methodology for the eigenvector perturbations using a predictor-corrector approach, which uses the incipient eigenvalue perturbations along with the Reynolds stress transport equations to determine the eigenvector perturbations. This approach was applied to benchmark cases of complex turbulent flows. The uncertainty intervals estimated using the proposed framework exhibited substantial improvement over eigenvalue-only perturbations and are able to account for a significant proportion of the discrepancy between RANS predictions and high-fidelity data