Co-transport-induced instability of membrane voltage in tip-growing cells

A salient feature of stationary patterns in tip-growing cells is the key role played by the symports and antiports, membrane proteins that translocate two ionic species at the same time. It is shown that these co-transporters destabilize generically the membrane voltage if the two translocated ions diffuse differently and carry a charge of opposite (same) sign for symports (antiports). Orders of magnitude obtained for the time and lengthscale are in agreement with experiments. A weakly nonlinear analysis characterizes the bifurcation

Expansion of Foxp3+ T-cell populations by Candida albicans enhances both Th17-cell responses and fungal dissemination after intravenous challenge

Research Funding Wellcome Trust, UK. Grant Numbers: 086827, 080088 NIH. Grant Number: DE022550Peer reviewedPublisher PD

A model of hyphal tip growth involving microtubule-based transport

We propose a simple model for mass transport within a fungal hypha and its subsequent growth. Inspired by the role of microtubule-transported vesicles, we embody the internal dynamics of mass inside a hypha with mutually excluding particles progressing stochastically along a growing one-dimensional lattice. The connection between long range transport of materials for growth, and the resulting extension of the hyphal tip has not previously been addressed in the modelling literature. We derive and analyse mean-field equations for the model and present a phase diagram of its steady state behaviour, which we compare to simulations. We discuss our results in the context of the filamentous fungus, Neurospora crassa.Comment: 5 pages, 5 figure

The X-ray quantum efficiency measurement of high resistivity CCDs

The CCD247 is the second generation of high-resistivity device to be manufactured in e2v technologies plc development programme. Intended for infrared astronomy, the latest devices are fabricated on high resistivity (~8 kΩ cm) bulk silicon, allowing for a greater device thickness whilst maintaining full depletion when 'thinned' to a thickness of 150 μm. In the case of the front illuminated variant, depletion of up to 300 μm is achievable by applying a gate to substrate potential of up to 120 V, whilst retaining adequate spectral performance. The increased depletion depth of high-resistivity CCDs greatly improves the quantum efficiency (QE) for incident X-ray photons of energies above 5 keV, making such a device beneficial in future X-ray astronomy missions and other applications. Here we describe the experimental setup and present results of X-ray QE measurements taken in the energy range 2-20 keV for a front illuminated CCD247, showing QE in excess of 80% at 10 keV. Results for the first generation CCD217 and swept-charge device (1500 Ω cm epitaxial silicon) are also presented

Investigation of Touch-Sensitive Responses by Hyphae of the Human Pathogenic Fungus Candida albicans

Candida albicans is a fungus that commonly infects the mucosal surface of humans. The hyphal growth form of this fungus may initiate the primary invasion of the host. Here we show that hyphae respond thigmotropically and morphologically to cues such as the presence of a surface, pores, grooves and ridges. Growth on some firm surfaces elicits a helical growth response. Hyphae follow grooves and ridges of inert substrates and penetrate pores of filtration membranes. Our in vitro experiments suggest that thigmotropism may enhance the ability of a hypha to invade epithelia of a host at sites of weakened integrity

Seasonal and dietary influences on adipose tissue and systemic gene expression in control and previously laminitic ponies

The aims of the study were to determine whether adipose tissue global gene expression (i) differs between never laminitic (NL) and previously laminitic (PL) ponies; (ii) is influenced by season and/or a diet designed to simulate spring grass and (iii) differences seen also occur systemically in peripheral blood mononuclear cells (PBMCs). Subcutaneous adipose tissue and PBMCs were obtained from six NL and six PL ponies on three occasions; summer, winter (season study) and in winter after consuming a diet simulating spring grass for seven days (diet study). Adipose tissue global gene expression was determined using a 44K equine specific microarray, validated using multiplex quantitative real time PCR (qRT-PCR) and analysed using GeneSpring software and Ingenuity Pathway Analysis. PBMC gene expression was quantified using qRT-PCR. The total number of genes whose expression differed (=2-fold change, p=0.01) between PL and NL ponies was greater in summer (192 genes) compared to winter (58 genes); 40/192 genes influenced by disease in the summer were also seasonally regulated and were predominantly associated with inflammation. The genes modified by dietary intervention and PBMC gene expression did not follow the same pattern as the season study. Thus, adipose tissue global gene expression differed between NL and PL ponies most in summer compared to winter, and these differentially expressed genes predominantly related to inflammation

VIS: the visible imager for Euclid

Euclid-VIS is a large format visible imager for the ESA Euclid space mission in their Cosmic Vision program, scheduled for launch in 2019. Together with the near infrared imaging within the NISP instrument it forms the basis of the weak lensing measurements of Euclid. VIS will image in a single r+i+z band from 550-900 nm over a field of view of ~0.5 deg2. By combining 4 exposures with a total of 2240 sec, VIS will reach to V=24.5 (10{\sigma}) for sources with extent ~0.3 arcsec. The image sampling is 0.1 arcsec. VIS will provide deep imaging with a tightly controlled and stable point spread function (PSF) over a wide survey area of 15000 deg2 to measure the cosmic shear from nearly 1.5 billion galaxies to high levels of accuracy, from which the cosmological parameters will be measured. In addition, VIS will also provide a legacy imaging dataset with an unprecedented combination of spatial resolution, depth and area covering most of the extra-Galactic sky. Here we will present the results of the study carried out by the Euclid Consortium during the Euclid Definition phase.Comment: 10 pages, 6 figure

How Many Lymph Nodes Are Enough? Assessing the Adequacy of Lymph Node Yield for Staging in Favorable Histology Wilms Tumor

© 2019 Elsevier Inc. Purpose: Current investigational priorities in the treatment of favorable histology Wilms tumor (FHWT) center on accurate staging and risk-stratification. The extent of lymph node (LN) sampling has not been clearly defined; its importance cannot be overstated as it guides adjuvant therapy. The identification of a minimum LN yield to minimize the risk of harboring occult metastatic disease could help development of surgical guidelines. This study focuses on using the beta-binomial distribution to estimate the risk of occult metastatic disease in patients with FHWT. Materials & methods: The National Cancer Database was queried for patients with unilateral FHWT from 2004 to 2013. Data were used to characterize nodal positivity for patients who underwent surgery and had ≥ 1 positive LN and ≥ 2 LNs examined. The probability of missing a positive LN (i.e., false negative) for a given LN yield was calculated using an empirical estimation and the beta-binomial model. Patients were then stratified by tumor size. Results: 422 patients met study criteria. To limit the chance of missing a positive LN to ≤ 10%, the empirical estimation and beta-binomial model estimated that 6 and 10 LNs needed to be sampled, respectively. Tumor size did not influence the result. Internal validation showed little variation to maintain a false negative rate ≤ 10%. Conclusions: Using mathematical modeling, it appears that the desired LN yield in FHWT to reduce the risk of false-negative LN sampling to ≤ 10% is between 6 and 10. The current analysis represents an objective attempt to determine the desired surgical approach to LN sampling to accurately stage patients with FHWT. Level of evidence: I