Applications of electrified dust and dust devil electrodynamics to Martian atmospheric electricity

Atmospheric transport and suspension of dust frequently brings electrification, which may be substantial. Electric fields of 10 kVm-1 to 100 kVm-1 have been observed at the surface beneath suspended dust in the terrestrial atmosphere, and some electrification has been observed to persist in dust at levels to 5 km, as well as in volcanic plumes. The interaction between individual particles which causes the electrification is incompletely understood, and multiple processes are thought to be acting. A variation in particle charge with particle size, and the effect of gravitational separation explains to, some extent, the charge structures observed in terrestrial dust storms. More extensive flow-based modelling demonstrates that bulk electric fields in excess of 10 kV m-1 can be obtained rapidly (in less than 10 s) from rotating dust systems (dust devils) and that terrestrial breakdown fields can be obtained. Modelled profiles of electrical conductivity in the Martian atmosphere suggest the possibility of dust electrification, and dust devils have been suggested as a mechanism of charge separation able to maintain current flow between one region of the atmosphere and another, through a global circuit. Fundamental new understanding of Martian atmospheric electricity will result from the ExoMars mission, which carries the DREAMS (Dust characterization, Risk Assessment, and Environment Analyser on the Martian Surface)-MicroARES (Atmospheric Radiation and Electricity Sensor) instrumentation to Mars in 2016 for the first in situ measurements

In vitro evaluation of Mucuna pruriens (L.) DC. antioxidant activity

Mucuna pruriens (L). Dc is a plant of the Fabaceae family, commonly known as velvet bean, itchy bean, chiporro bean, mucuna, among others. This plant has several medicinal properties, including its potential to treat Parkinson's disease (PD). International studies have shown that this plant surpasses the benefits of the substance levodopa in the treatment of PD. Taking into account that nerve cells are highly sensitive to oxidative substances, this study evaluated the antioxidant activity of mucuna and compared it to that of levodopa. The plant seeds' phenolic concentration was quantified by using the Folin-Denis reagent and the antioxidant activity assays were performed by using three different methods: the reduction of the phosphomolybdenium complex, the reduction of radical 1,1-diphenyl-2-picrylhydrazyl (DPPH•) and the formation of radical monocation ABTS•+, from the acid [2-2'-azinobis (3-ethylbenzothiazoline-6-sulfonate)]. Results showed that M. pruriens presents high antioxidant capacity, although not superior to isolated levodopa antioxidant capacity. Therefore, further studies should be performed to elucidate the activity of this plant in humans.A Mucuna pruriens (L). Dc é uma planta da família Fabaceae, conhecida popularmente como feijão-veludo, fava-coceira, feijão chiporro, mucuna, entre outros. Possui diversas propriedades medicinais, entre elas, o tratamento da doença de Parkinson (DP). Estudos internacionais vêm demonstrando que essa planta possui atividade superior à do fármaco levodopa para o tratamento da DP. O presente estudo avaliou a possibilidade da atividade antioxidante dessa planta auxiliar nesses resultados, uma vez que as células nervosas são altamente sensíveis às substâncias oxidativas. Para isto foi quantificada a concentração fenólica da semente da mucuna e os testes empregados para a avaliação da atividade antioxidante foram o teste de redução do complexo fosfomolibdênio, redução do radical 1,1-difenil-2-picril-hidrazil (DPPH•) e a formação do radical monocatiônico ABTS•+, proveniente do ácido [2-2'-azino-bis(3-etil-benzolina-6-sulfonado)]. Essa análise demonstrou que M. pruriens possui alta capacidade antioxidante, no entanto, não superior à levodopa isolada e, portanto, novos estudos devem ser realizados para a elucidação da atividade dessa planta em seres humanos

Comparing Presenting Clinical Features in 48 Children With Microscopic Polyangiitis to 183 Children Who Have Granulomatosis With Polyangiitis (Wegener's) : an ARChiVe Cohort Study

OBJECTIVE: To uniquely classify children with microscopic polyangiitis (MPA), to describe their demographic characteristics, presenting clinical features, and initial treatments in comparison to patients with granulomatosis with polyangiitis (Wegener's) (GPA). METHODS: The European Medicines Agency (EMA) classification algorithm was applied by computation to categorical data from patients recruited to the ARChiVe (A Registry for Childhood Vasculitis: e-entry) cohort, with the data censored to November 2015. The EMA algorithm was used to uniquely distinguish children with MPA from children with GPA, whose diagnoses had been classified according to both adult- and pediatric-specific criteria. Descriptive statistics were used for comparisons. RESULTS: In total, 231 of 440 patients (64% female) fulfilled the classification criteria for either MPA (n\u2009=\u200948) or GPA (n\u2009=\u2009183). The median time to diagnosis was 1.6 months in the MPA group and 2.1 months in the GPA group (ranging to 39 and 73 months, respectively). Patients with MPA were significantly younger than those with GPA (median age 11 years versus 14 years). Constitutional features were equally common between the groups. In patients with MPA compared to those with GPA, pulmonary manifestations were less frequent (44% versus 74%) and less severe (primarily, hemorrhage, requirement for supplemental oxygen, and pulmonary failure). Renal pathologic features were frequently found in both groups (75% of patients with MPA versus 83% of patients with GPA) but tended toward greater severity in those with MPA (primarily, nephrotic-range proteinuria, requirement for dialysis, and end-stage renal disease). Airway/eye involvement was absent among patients with MPA, because these GPA-defining features preclude a diagnosis of MPA within the EMA algorithm. Similar proportions of patients with MPA and those with GPA received combination therapy with corticosteroids plus cyclophosphamide (69% and 78%, respectively) or both drugs in combination with plasmapheresis (19% and 22%, respectively). Other treatments administered, ranging in decreasing frequency from 13% to 3%, were rituximab, methotrexate, azathioprine, and mycophenolate mofetil. CONCLUSION: Younger age at disease onset and, perhaps, both gastrointestinal manifestations and more severe kidney disease seem to characterize the clinical profile in children with MPA compared to those with GPA. Delay in diagnosis suggests that recognition of these systemic vasculitides is suboptimal. Compared with adults, initial treatment regimens in children were comparable, but the complete reversal of female-to-male disease prevalence ratios is a provocative finding

The influence of recombinant human insulin-like growth factor-I (rhIGF-I) on cell growth and cytotoxicity of drugs in childhood rhabdomyosarcoma cell lines and xenograft models

Purpose: Recombinant human insulin-like growth factor I (rhIGF-I) has been reported to ameliorate vincristine-induced neuropathy, the dose-limiting side effect of this antimitotic anticancer drug. However, rhIGF-I also might have adverse effects, as has been shown in vitro, where it stimulates growth of cancer cells and protects them from cytotoxicity of anticancer drugs. The influence of rhIGF-I on the cytotoxicity of vincristine has not yet been studied. Furthermore, studies performed have been done under serum-free conditions, which are far from physiological. Methods: We studied the influence of rhIGF-I on the growth of two rhabdomyosarcoma cell lines (Rh30 and Rh1) and on the antitumor effects of vincristine, cisplatin, etoposide, doxorubicin, and topotecan under serum-free and serum-containing conditions. To extend the in vitro data, we grew Rh30 cells as xenografts in mice and determined the effects of vincristine, rhIGF-I or their combination on tumor growth. Results: In vitro, both cell lines demonstrated a functional type I IGF receptor, as shown by the rapid activation of ribosomal p70 S6 kinase after stimulation with rhIGF-I. Under serum-free conditions, rhIGF-I stimulated growth of both cell lines. Exposure to cytotoxic drugs with and without rhIGF-I resulted in higher cell numbers in cultures exposed to rhIGF-I. However, relative to the appropriate control, fractional growth inhibition and or cell kill of the cytotoxic drugs was identical with and without rhIGF-I. Under serum-containing conditions, rhIGF-I had no effect on cell growth or drug cytotoxicity. In vivo we did not find a significant influence of rhIGF-I on HxRh30 cell growth, or on the antitumor activity of vincristine. Conclusions: These studies show that rhIGF-I has no adverse effects on human rhabdomyosarcoma growth or on the antitumor effect of cytotoxic drugs under serum-containing conditions in vitro or in tumor-bearing mice. Potentially, therefore, rhIGF-I may ameliorate vincristine-induced neuropathy without adversely influencing tumor growth or vincristine cytotoxicity in children

The Audit Expectation Gap between Companies and Their Auditors: An Exploratory Study

This exploratory study aims to provide insight into the audit expectation gap between companies and their auditors measured by the materiality for the financial statement as a whole, defined for the purpose of this paper as the materiality gap. This gap, conceived as a component of the audit expectation gap, is little examined in literature. In order to investigate the existence of a materiality gap, financial statement preparers of the selected companies were asked to estimate the materiality of their financial statement. This was subsequently compared with the outcome of the materiality used by the auditor based on the audit file. Moreover, to obtain more insight into the possible materiality gap, a survey was sent out to the partners of the audit firm involved. This study shows that materiality levels assumed by the preparers of financial statements were lower than the materiality actually applied by the auditors

Costs of plasticity: responses to desiccation decrease post-metamorphic immune function in a pond-breeding amphibian

1.   Phenotypic plasticity may allow an organism to respond to temporally variable opportunities for growth and risks of mortality. However, life-history theory assumes that there are often trade-offs between the benefits afforded by plasticity in one trait and the consequences of that plasticity on other traits that affect fitness. In organisms with a complex life cycle, trade-offs may occur between larval and post-metamorphic traits. 2.   Many amphibians metamorphose in temporary ponds, and may accelerate larval development to avoid mortality when a pond desiccates. A younger age at metamorphosis often results in reduced body size, but may also facilitate a trade-off with physiological traits that are linked to fitness in the adult stage. 3.   We investigated a potential trade-off between desiccation-driven acceleration of development rate and immune system responsiveness in a species that breeds exclusively in temporary ponds. We exposed Rana sylvatica (wood frog) tadpoles to four possible desiccation regimes and then assayed the cell-mediated immune response to a standardized foreign antigen, phytohaemagglutinin (PHA), injected 3 weeks after metamorphosis. We also quantified total leucocyte numbers from haematological smears to obtain a secondary measure of individual immunological condition. 4.   Animals exposed to desiccation had shorter development times, weaker cellular immune system responses to PHA and lower total leucocyte numbers than animals from control groups. Both measures of immune response showed a decrease with increasing severity of the desiccation treatment. 5.   It is currently unclear whether the observed depression in immune response is transient or permanent. However, even temporary periods of immune system suppression shortly after metamorphosis may lead to greater susceptibility to opportunistic pathogens or parasites.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74472/1/j.1365-2435.2007.01340.x.pd