Intramammary immunization of pregnant mice with staphylococcal protein a reduces the post-challenge mammary gland bacterial load but not pathology

Protein A, encoded by the spa gene, is one of the major immune evading MSCRAMM of S. aureus, demonstrated to be prevalent in a significant percentage of clinical bovine mastitis isolates in Australia. Given its' reported significance in biofilm formation and the superior performance of S. aureus biofilm versus planktonic vaccine in the mouse mastitis model, it was of interest to determine the immunogenicity and protective potential of Protein A as a potential vaccine candidate against bovine mastitis using the mouse mastitis model. Pregnant Balb/c mice were immunised with Protein A emulsified in an alum-based adjuvant by subcutaneous (s/c) or intramammary (i/mam) routes. While humoral immune response of mice post-immunization were determined using indirect ELISA, cell-mediated immune response was assessed by estimation of interferon-gamma (IFN-γ) produced by protein A-stimulated splenocyte supernatants. Protective potential of Protein A against experimental mastitis was determined by challenge of immunized versus sham-vaccinated mice by i/mam route, based upon manifestation of clinical symptoms, total bacterial load and histopathological damage to mammary glands. Significantly (p<0.05) higher levels of IgG1 isotype were produced in mice immunized by the s/c route. In contrast, significantly higher levels of the antibody isotype IgG2a were produced in mice immunized by the i/mam route (p<0.05). There was significant reduction (p<0.05) in bacterial loads of the mammary glands of mice immunized by Protein A regardless of the route of immunization, with medium level of clinical symptoms observed up to day 3 post-challenge. However, Protein A vaccine failed to protect immunized mice post-challenge with biofilm producing encapsulated S. aureus via i/mam route, regardless of the route of immunization, as measured by the level of mammary tissue damage. It was concluded that, Protein A in its' native state was apparently not a suitable candidate for inclusion in a cell-free vaccine formulation against mastitis

The Erpenbeck high frequency instability theorem for ZND detonations

The rigorous study of spectral stability for strong detonations was begun by J.J. Erpenbeck in [Er1]. Working with the Zeldovitch-von Neumann-D\"oring (ZND) model, which assumes a finite reaction rate but ignores effects like viscosity corresponding to second order derivatives, he used a normal mode analysis to define a stability function V(\tau,\eps) whose zeros in $\Re \tau>0$ correspond to multidimensional perturbations of a steady detonation profile that grow exponentially in time. Later in a remarkable paper [Er3] he provided strong evidence, by a combination of formal and rigorous arguments, that for certain classes of steady ZND profiles, unstable zeros of $V$ exist for perturbations of sufficiently large transverse wavenumber \eps, even when the von Neumann shock, regarded as a gas dynamical shock, is uniformly stable in the sense defined (nearly twenty years later) by Majda. In spite of a great deal of later numerical work devoted to computing the zeros of V(\tau,\eps), the paper \cite{Er3} remains the only work we know of that presents a detailed and convincing theoretical argument for detecting them. The analysis in [Er3] points the way toward, but does not constitute, a mathematical proof that such unstable zeros exist. In this paper we identify the mathematical issues left unresolved in [Er3] and provide proofs, together with certain simplifications and extensions, of the main conclusions about stability and instability of detonations contained in that paper. The main mathematical problem, and our principal focus here, is to determine the precise asymptotic behavior as \eps\to \infty of solutions to a linear system of ODEs in $x$, depending on \eps and a complex frequency $\tau$ as parameters, with turning points $x_*$ on the half-line $[0,\infty)$

Seed coat mediated resistance against Aspergillus flavus infection in peanut

Toxic metabolites known as aflatoxins are produced via certain species of the Aspergillus genus, specifically A. flavus, A. parasiticus, A. nomius, and A. tamarie. Although various pre- and post-harvest strategies have been employed, aflatoxin contamination remains a major problem within peanut crop, especially in subtropical environments. Aflatoxins are the most well-known and researched mycotoxins produced within the Aspergillus genus (namely Aspergillus flavus) and are classified as group 1 carcinogens. Their effects and etiology have been extensively researched and aflatoxins are commonly linked to growth defects and liver diseases in humans and livestock. Despite the known importance of seed coats in plant defense against pathogens, peanut seed coat mediated defenses against Aspergillus flavus resistance, have not received considerable attention. The peanut seed coat (testa) is primarily composed of a complex cell wall matrix consisting of cellulose, lignin, hemicellulose, phenolic compounds, and structural proteins. Due to cell wall desiccation during seed coat maturation, postharvest A. flavus infection occurs without the pathogen encountering any active genetic resistance from the live cell(s) and the testa acts as a physical and biochemical barrier only against infection. The structure of peanut seed coat cell walls and the presence of polyphenolic compounds have been reported to inhibit the growth of A. flavus and aflatoxin contamination; however, there is no comprehensive information available on peanut seed coat mediated resistance. We have recently reviewed various plant breeding, genomic, and molecular mechanisms, and management practices for reducing A. flavus infection and aflatoxin contamination. Further, we have also proved that seed coat acts as a physical and biochemical barrier against A. flavus infection. The current review focuses specifically on the peanut seed coat cell wall-mediated disease resistance, which will enable researchers to understand the mechanism and design efficient strategies for seed coat cell wall-mediated resistance against A. flavus infection and aflatoxin contamination

Vortex structure in d-density wave scenario of pseudogap

We investigate the vortex structure assuming the d-density wave scenario of the pseudogap. We discuss the profiles of the order parameters in the vicinity of the vortex, effective vortex charge and the local density of states. We find a pronounced modification of these quantities when compared to a purely superconducting case. Results have been obtained for a clean system as well as in the presence of a nonmagnetic impurity. We show that the competition between superconductivity and the density wave may explain some experimental data recently obtained for high-temperature superconductors. In particular, we show that the d-density wave scenario explains the asymmetry of the gap observed in the vicinity of the vortex core.Comment: 8 pages, 10 figure

Interaction of vortices in viscous planar flows

We consider the inviscid limit for the two-dimensional incompressible Navier-Stokes equation in the particular case where the initial flow is a finite collection of point vortices. We suppose that the initial positions and the circulations of the vortices do not depend on the viscosity parameter \nu, and we choose a time T > 0 such that the Helmholtz-Kirchhoff point vortex system is well-posed on the interval [0,T]. Under these assumptions, we prove that the solution of the Navier-Stokes equation converges, as \nu -> 0, to a superposition of Lamb-Oseen vortices whose centers evolve according to a viscous regularization of the point vortex system. Convergence holds uniformly in time, in a strong topology which allows to give an accurate description of the asymptotic profile of each individual vortex. In particular, we compute to leading order the deformations of the vortices due to mutual interactions. This allows to estimate the self-interactions, which play an important role in the convergence proof.Comment: 39 pages, 1 figur

Structure and Dynamics of Liquid Iron under Earth's Core Conditions

First-principles molecular dynamics simulations based on density-functional theory and the projector augmented wave (PAW) technique have been used to study the structural and dynamical properties of liquid iron under Earth's core conditions. As evidence for the accuracy of the techniques, we present PAW results for a range of solid-state properties of low- and high-pressure iron, and compare them with experimental values and the results of other first-principles calculations. In the liquid-state simulations, we address particular effort to the study of finite-size effects, Brillouin-zone sampling and other sources of technical error. Results for the radial distribution function, the diffusion coefficient and the shear viscosity are presented for a wide range of thermodynamic states relevant to the Earth's core. Throughout this range, liquid iron is a close-packed simple liquid with a diffusion coefficient and viscosity similar to those of typical simple liquids under ambient conditions.Comment: 13 pages, 8 figure

Geriatric assessment predicts hospitalization frequency and long-term care use in older adult cancer survivors

PURPOSE The association between geriatric assessment (GA)–identified impairments and long-term health care use in older cancer survivors remains unknown. Our objective was to evaluate whether a GA performed at cancer diagnosis was predictive of hospitalizations and long-term care (LTC) use in older adult cancer survivors. METHODS Older adults with GA performed between 3 months before through 6 months after diagnosis were included (N = 125). Patients with Medicare Parts A and B coverage and no managed care were identified. Hospitalizations and LTC use (skilled nursing or assisted living) were assessed up to 5 years postdiagnosis. GA risk measures were evaluated in separate Poisson models estimating the relative risk (RR) for hospital and LTC visits, adjusting for age and Charlson comorbidity score. RESULTS The mean age of patients was 74 years, and the majority were female (80%) and white (90%). Breast cancer (64%) and early-stage disease (stages 0 to III, 77%) were common. Prefrail/frail status (RR, 2.5; P, .001), instrumental activities of daily living impairment (RR, 5.47; P, .001), and limitations in climbing stairs (RR, 2.94; P, .001) were associated with increased hospitalizations. Prefrail/frail status (RR, 1.86; P, .007), instrumental activities of daily living impairment (RR, 4.58; P, .001), presence of falls (RR, 6.73; P, .001), prolonged Timed Up and Go (RR, 5.45; P, .001), and limitations in climbing stairs (RR, 1.89; P, .005) were associated with LTC use. CONCLUSION GA-identified impairments were associated with increased hospitalizations and LTC use among older adults with cancer. GA-focused interventions should be targeted toward high-risk patients to reduce long-term adverse health care use in this vulnerable population

Patient-Reported Comorbidity and Survival in Older Adults with Cancer

Background: Our ability to optimize the care of older adults with cancer and comorbid illnesses is insufficient because most clinical trials lack systematic measurement. The primary purpose of this study was to evaluate the association between patient-reported comorbidity and all-cause mortality using various comorbidity scoring algorithms. Materials and Methods: The Carolina Senior Registry was linked with the North Carolina Central Cancer Registry to obtain mortality data. Comorbidity was assessed using the patient-reported Older Americans Resources and Services Questionnaire subscale that assesses 13 specific conditions and the degree to which each impairs activities. Multivariable Cox proportional hazard regression models were used to evaluate the association between comorbidities and all-cause mortality. Results: The study sample included 539 patients; the median age was 72 years, 72% were female, and 47% had breast cancer. Overall, 92% reported ≥1 comorbid condition, with a mean of 2.7 conditions (range 0–10), with arthritis and hypertension the most common (52% and 50%, respectively). Approximately 60% reported a functional limitation related to comorbidity. After adjusting for time from diagnosis to geriatric assessment, age, cancer type, and stage, the risk of death increased by 5% for each unit increase in comorbidity burden score (adjusted hazard ratio [HR] = 1.05, 95% confidence interval [CI]: 1.01–1.10) and 12% for each comorbid condition impacting function (HR = 1.12, 95% CI: 1.02–1.23). Conclusion: Comorbid conditions in older adults with cancer are highly prevalent and associated with all-cause mortality, particularly those conditions that impair function. Routine comorbidity assessment should be included in clinical trials and can be measured via a simple one-page patient-reported questionnaire. Implications for Practice: In order to optimize and personalize the care of older adults with cancer, systematic measurement of comorbidities is necessary in both clinical trials and routine practice. Patient-reported comorbid conditions in older adults with cancer are highly prevalent and are associated with increased risk of all-cause mortality, particularly for those conditions that impair function. Comorbidity can be systematically measured via a one-page patient-reported questionnaire and should be incorporated into future clinical trials and considered for use in oncology clinics to aid in assessing older adults with cancer

Hydrellia lagarosiphon Deeming (Diptera: Ephydridae), a potential biological control agent for the submerged aquatic weed, Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae)

The leaf-mining fly, Hydrellia lagarosiphon Deeming (Diptera: Ephydridae), was investigated in its native range in South Africa, to determine its potential as a biological control agent for Lagarosiphon major (Ridl.) Moss ex Wager (Hydrocharitaceae), an invasive submerged macrophyte that is weedy in many parts of the world. The fly was found throughout the indigenous range of the plant in South Africa. High larval abundance was recorded at field sites with nearly all L. major shoots sampled ontaining larvae, with densities of up to 10 larvae per shoot. Adults laid batches of up to 15 eggs, usually on the abaxial sides of L. major leaves. The larvae mined internally, leaving the epidermal tissues of the upper and lower leaves intact. The larvae underwent three instars which took an average of 24 days and pupated within the leaf tissue, from which the adults emerged. Impact studies in the laboratory showed that H. lagarosiphon larval feeding significantly restricted the formation of L. major side branches. Based on its biology and damage caused to the plant, Hydrellia lagarosiphon could be considered as a useful biological control candidate for L. major in countries where the plant is invasive