Limiting opportunities for cheating stabilizes virulence in insect parasitic nematodes

Cooperative secretion of virulence factors by pathogens can lead to social conflict when cheating mutants exploit collective secretion, but do not contribute to it. If cheats outcompete cooperators within hosts, this can cause loss of virulence. Insect parasitic nematodes are important biocontrol tools that secrete a range of significant virulence factors. Critically, effective nematodes are hard to maintain without live passage, which can lead to virulence attenuation. Using experimental evolution, we tested whether social cheating might explain unstable virulence in the nematode Heterorhabditis floridensis by manipulating relatedness via multiplicity of infection (MOI), and the scale of competition. Passage at high MOI, which should reduce relatedness, led to loss of fitness: virulence and reproductive rate declined together and all eight independent lines suffered premature extinction. As theory predicts, relatedness treatments had more impact under stronger global competition. In contrast, low MOI passage led to more stable virulence and increased reproduction. Moreover, low MOI lineages showed a trade-off between virulence and reproduction, particularly for lines under stronger between-host competition. Overall, this study indicates that evolution of virulence theory is valuable for the culture of biocontrol agents: effective nematodes can be improved and maintained if passage methods mitigate possible social conflicts

A new mechanism of SOX9 action to regulate PKC expression in the intestine epithelium

International audienceVariations of protein kinase C (PKC) expression greatly influence the proliferation-to-differentiation transition (PDT) of intestinal epithelial cells and might have an important impact on intestinal tumorigenesis. We demonstrate here that the expression of PKCalpha in proliferating intestinal epithelial cells is repressed both in vitro and in vivo by the SOX9 transcription factor. This repression does not require DNA binding of the SOX9 high-mobility group (HMG) domain but is mediated through a new mechanism of SOX9 action requiring the central and highly conserved region of SOXE members. Because SOX9 expression is itself upregulated by Wnt-APC signaling in intestinal epithelial cells, the present study points out this transcription factor as a molecular link between the Wnt-APC pathway and PKCalpha. These results provide a potential explanation for the decrease of PKCalpha expression in colorectal cancers with constitutive activation of the Wnt-APC pathway

A generalized Tullock contest

We construct a generalized Tullock contest under complete information where contingent upon winning or losing, the payoff of a player is a linear function of prizes, own effort, and the effort of the rival. This structure nests a number of existing contests in the literature and can be used to analyze new types of contests. We characterize the unique symmetric equilibrium and show that small parameter modifications may lead to substantially different types of contests and hence different equilibrium effort levels

Repurposing a photosynthetic antenna protein as a super-resolution microscopy label

Techniques such as Stochastic Optical Reconstruction Microscopy (STORM) and Structured Illumination Microscopy (SIM) have increased the achievable resolution of optical imaging, but few fluorescent proteins are suitable for super-resolution microscopy, particularly in the far-red and near-infrared emission range. Here we demonstrate the applicability of CpcA, a subunit of the photosynthetic antenna complex in cyanobacteria, for STORM and SIM imaging. The periodicity and width of fabricated nanoarrays of CpcA, with a covalently attached phycoerythrobilin (PEB) or phycocyanobilin (PCB) chromophore, matched the lines in reconstructed STORM images. SIM and STORM reconstructions of Escherichia coli cells harbouring CpcA-labelled cytochrome bd 1 ubiquinol oxidase in the cytoplasmic membrane show that CpcA-PEB and CpcA-PCB are suitable for super-resolution imaging in vivo. The stability, ease of production, small size and brightness of CpcA-PEB and CpcA-PCB demonstrate the potential of this largely unexplored protein family as novel probes for super-resolution microscopy

PHAEOCHROMOCYTOMA

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72570/1/j.1445-2197.1988.tb01080.x.pd

Clinical course of untreated cervical intraepithelial neoplasia grade 2 under active surveillance : systematic review and meta-analysis

OBJECTIVE To estimate the regression, persistence, and progression of untreated cervical intraepithelial neoplasia grade 2 (CIN2) lesions managed conservatively as well as compliance with follow-up protocols. DESIGN Systematic review and meta-analysis. DATA SOURCES Medline, Embase, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) from 1 January 1973 to 20 August 2016. ELIGIBILITY CRITERIA Studies reporting on outcomes of histologically confirmed CIN2 in non-pregnant women, managed conservatively for three or more months. DATA SYNTHESIS Two reviewers extracted data and assessed risk of bias. Random effects model was used to calculate pooled proportions for each outcome, and heterogeneity was assessed using I-2 statistics. MAIN OUTCOME MEASURES Rates of regression, persistence, or progression of CIN2 and default rates at different follow-up time points (3, 6, 12, 24, 36, and 60 months). RESULTS 36 studies that included 3160 women were identified (seven randomised trials, 16 prospective cohorts, and 13 retrospective cohorts; 50% of the studies were at low risk of bias). At 24 months, the pooled rates were 50% (11 studies, 819/1470 women, 95% confidence interval 43% to 57%; I-2= 77%) for regression, 32% (eight studies, 334/1257 women, 23% to 42%; I-2= 82%) for persistence, and 18% (nine studies, 282/1445 women, 11% to 27%; I-2= 90%) for progression. In a subgroup analysis including 1069 women aged less than 30 years, the rates were 60% (four studies, 638/1069 women, 57% to 63%; I-2= 0%), 23% (two studies, 226/938 women, 20% to 26%; I-2= 97%), and 11% (three studies, 163/1033 women, 5% to 19%; I-2= 67%), respectively. The rate of non-compliance (at six to 24 months of follow-up) in prospective studies was around 10%. CONCLUSIONS Most CIN2 lesions, particularly in young women (<30 years), regress spontaneously. Active surveillance, rather than immediate intervention, is therefore justified, especially among young women who are likely to adhere to monitoring.Peer reviewe

Magnetism and Structural Distortion in the La0.7Sr0.3MnO3 Metallic Ferromagnet

Neutron scattering studies on a single crystal of the highly-correlated electron system, La1-xSrxMnO3 with x~0.3, have been carried out elucidating both the spin and lattice dynamics of this metallic ferromagnet. We report a large measured value of the spin wave stiffness constant, which directly shows that the electron transfer energy of the d band is large. The spin dynamics, including magnetic critical scattering, demonstrate that this material behaves similar to other typical metallic ferromagnets such as Fe or Ni. The crystal structure is rhombohedral, as previously reported, for all temperatures studied (below ~425K). We have observed new superlattice peaks which show that the primary rhombohedral lattice distortion arises from oxygen octahedra rotations resulting in an R-3c structure. The superlattice reflection intensities which are very sensitive to structural changes are independent of temperature demonstrating that there is no primary lattice distortion anomaly at the magnetic transition temperature, Tc = 378.1 K, however there is a lattice contraction.Comment: Submitted to Phys. Rev. B. (03Aug95) Uuencoded gz-compressed .tar file of Postscript text (12 pages) and 6 figures. Also available by WWW from http://insti.physics.sunysb.edu/~mmartin/ under my list of publications or by e-mail reques

High pressure phases in highly piezoelectric Pb(Zr0.52Ti0.48)O3

Two novel room-temperature phase transitions are observed, via synchrotron x-ray diffraction and Raman spectroscopy, in the Pb(Zr0.52Ti0.48)O3 alloy under hydrostatic pressures up to 16 GPa. A monoclinic (M)-to-rhombohedral (R1) phase transition takes place around 2-3 GPa, while this R1 phase transforms into another rhombohedral phase, R2, at about 6-7 GPa. First-principles calculations assign the R3m and R3c symmetry to R1 and R2, respectively, and reveal that R2 acts as a pressure-induced structural bridge between the polar R3m and a predicted antiferrodistortive R-3c phase.Comment: REVTeX, 4 pages with 3 figures embedded. Figs 1 and 3 in colo