Large scale localization of protein phosphorylation by use of electron capture dissociation mass spectrometry.

We used on-line electron capture dissociation (ECD) for the large scale identification and localization of sites of phosphorylation. Each FT-ICR ECD event was paired with a linear ion trap collision-induced dissociation (CID) event, allowing a direct comparison of the relative merits of ECD and CID for phosphopeptide identification and site localization. Linear ion trap CID was shown to be most efficient for phosphopeptide identification, whereas FT-ICR ECD was superior for localization of sites of phosphorylation. The combination of confident CID and ECD identification and confident CID and ECD localization is particularly valuable in cases where a phosphopeptide is identified just once within a phosphoproteomics experiment

Exploring the genetic regulation of asexual sporulation in Zymoseptoria tritici

<p>Zymoseptoria tritici is the causal agent of septoria tritici blotch, a devastating fungal disease of wheat which can cause up to 40% yield loss. One of the ways in which Z. tritici spreads in the field is via rain splash-dispersed asexual pycnidiospores, however there is currently limited understanding of the genetic mechanisms governing the development of these propagules. In order to explore whether the existing models for conidiation in ascomycete fungi apply to Z. tritici, homologs to the well-characterized Aspergillus nidulans genes abacus (abaA), bristle (brlA), fluffy B (flbB), fluffy C (flbC), and stunted (stuA) were identified and knocked-out by Agrobacterium-mediated transformation. Although deletion of the ZtAbaA, ZtBrlA1, and ZtFlbB genes had no apparent effect on Z. tritici asexual sporulation or on pathogenicity, deletion of ZtFlbC or ZtBrlA2 resulted in mutants with reduced pycnidiospore production compared to the parental IPO323 strain. Deletion of ZtStuA gave non-pigmented mutants with altered vegetative growth and eliminated asexual sporulation and pathogenicity. These findings suggest that the well-established A. nidulans model of asexual sporulation is only partially applicable to Z. tritici, and that this pathogen likely uses additional, as yet uncharacterized genes to control asexual sporulation.</p

The Role of Cutaneous Receptors in the Menton Tap Silent Period

The neuromuscular mechanisms of the electromyographic silent period are poorly understood but clinically significant. Our purpose was to isolate the contribution of cutaneous afferents from the chin to the latency and the duration of the EMG silent period. Under the conditions of our experiment, the afferents of the mental nerve have no observable influence on the latency or the duration of the silent period educed by a menton tap.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66492/2/10.1177_00220345790580011001.pd

Lorentz-violating effects on topological defects generated by two real scalar fields

The influence of a Lorentz-violation on soliton solutions generated by a system of two coupled scalar fields is investigated. Lorentz violation is induced by a fixed tensor coefficient that couples the two fields. The Bogomol'nyi method is applied and first-order differential equations are obtained whose solutions minimize energy and are also solutions of the equations of motion. The analysis of the solutions in phase space shows how the stability is modified with the Lorentz violation. It is shown explicitly that the solutions preserve linear stability despite the presence of Lorentz violation. Considering Lorentz violation as a small perturbation, an analytical method is employed to yield analytical solutions.Comment: (9 pages, 11 figures

Magnetic flux inversion in Charged BPS vortices in a Lorentz-violating Maxwell-Higgs framework

We demonstrate for the first the existence of electrically charged BPS vortices in a Maxwell-Higgs model supplemented with a parity-odd Lorentz-violating (LV) structure belonging to the CPT-even gauge sector of the standard model extension and a fourth order potential (in the absence of the Chern-Simons term). The modified first order BPS equations provide charged vortex configurations endowed with some interesting features: localized and controllable spatial thickness, integer flux quantization, electric field inversion and localized magnetic flux reversion. This model could possibly be applied on condensed matter systems which support charged vortices carrying integer quantized magnetic flux, endowed with localized flipping of the magnetic flux.Comment: 6 Latex 2e pages, 5 figures. To appear in Physics Letters

The value of nonlinear control theory in investigating the underlying dynamics and resilience of a grocery supply chain

In an empirical context, a method to use nonlinear control theory in the dynamic analysis of supply chain resilience is developed and tested. The method utilises block diagram development, transfer function formulation, describing function representation of nonlinearities and simulation. Using both ‘shock’ or step response and ‘filter’ or frequency response lenses, a system dynamics model is created to analyse the resilience performance of a distribution centre replenishment system at a large grocery retailer. Potential risks for the retailer’s resilience performance include the possibility of a mismatch between supply and demand, as well as serving the store inefficiently and causing on-shelf stock-outs. Thus, resilience is determined by investigating the dynamic behaviour of stock and shipment responses. The method allows insights into the nonlinear system control structures that would not be evident using simulation alone, including a better understanding of the influence of control parameters on dynamic behaviour, the identification of inventory offsets potentially leading to ‘drift’, the impact of nonlinearities on supply chain performance and the minimisation of simulation experiments

The Science of Sungrazers, Sunskirters, and Other Near-Sun Comets

This review addresses our current understanding of comets that venture close to the Sun, and are hence exposed to much more extreme conditions than comets that are typically studied from Earth. The extreme solar heating and plasma environments that these objects encounter change many aspects of their behaviour, thus yielding valuable information on both the comets themselves that complements other data we have on primitive solar system bodies, as well as on the near-solar environment which they traverse. We propose clear definitions for these comets: We use the term near-Sun comets to encompass all objects that pass sunward of the perihelion distance of planet Mercury (0.307 AU). Sunskirters are defined as objects that pass within 33 solar radii of the Sun’s centre, equal to half of Mercury’s perihelion distance, and the commonly-used phrase sungrazers to be objects that reach perihelion within 3.45 solar radii, i.e. the fluid Roche limit. Finally, comets with orbits that intersect the solar photosphere are termed sundivers. We summarize past studies of these objects, as well as the instruments and facilities used to study them, including space-based platforms that have led to a recent revolution in the quantity and quality of relevant observations. Relevant comet populations are described, including the Kreutz, Marsden, Kracht, and Meyer groups, near-Sun asteroids, and a brief discussion of their origins. The importance of light curves and the clues they provide on cometary composition are emphasized, together with what information has been gleaned about nucleus parameters, including the sizes and masses of objects and their families, and their tensile strengths. The physical processes occurring at these objects are considered in some detail, including the disruption of nuclei, sublimation, and ionisation, and we consider the mass, momentum, and energy loss of comets in the corona and those that venture to lower altitudes. The different components of comae and tails are described, including dust, neutral and ionised gases, their chemical reactions, and their contributions to the near-Sun environment. Comet-solar wind interactions are discussed, including the use of comets as probes of solar wind and coronal conditions in their vicinities. We address the relevance of work on comets near the Sun to similar objects orbiting other stars, and conclude with a discussion of future directions for the field and the planned ground- and space-based facilities that will allow us to address those science topics

Postnatal Zika virus infection is associated with persistent abnormalities in brain structure, function, and behavior in infant macaques

The Zika virus (ZIKV) epidemic is associated with fetal brain lesions and other serious birth defects classified as congenital ZIKV syndrome. Postnatal ZIKV infection in infants and children has been reported; however, data on brain anatomy, function, and behavioral outcomes following infection are absent. We show that postnatal ZIKV infection of infant rhesus macaques (RMs) results in persistent structural and functional alterations of the central nervous system compared to age-matched controls. We demonstrate ZIKV lymphoid tropism and neurotropism in infant RMs and histopathologic abnormalities in the peripheral and central nervous systems including inflammatory infiltrates, astrogliosis, and Wallerian degeneration. Structural and resting-state functional magnetic resonance imaging (MRI/rs-fMRI) show persistent enlargement of lateral ventricles, maturational changes in specific brain regions, and altered functional connectivity (FC) between brain areas involved in emotional behavior and arousal functions, including weakened amygdala-hippocampal connectivity in two of two ZIKV-infected infant RMs several months after clearance of ZIKV RNA from peripheral blood. ZIKV infection also results in distinct alterations in the species-typical emotional reactivity to acute stress, which were predicted by the weak amygdala-hippocampal FC. We demonstrate that postnatal ZIKV infection of infants in this model affects neurodevelopment, suggesting that long-term clinical monitoring of pediatric cases is warranted