1,969 research outputs found
Stationary plasmas in Vlasov theory
High temperature laboratory and rarefied space plasmas can be considered in many situations as collisionless and described by kinetic theory. The fundamental dynamics of the system is regulated by the Vlasov equation (collisionless Boltzmann equation) for the evolution of the distribution functions of the species present in the plasma, coupled to Maxwell's equations for the electromagnetic fields. This nonlinear system of equations relates self-consistently the fields to their source terms that are given by the moments of the distribution functions in velocity space. In this work stationary solutions of the coupled Vlasov-Maxwell system will be explored, in order to find interesting equilibrium configurations in plasmas. These stationary solutions of the Vlasov-Maxwell system are of interest because both for astrophysical and laboratory plasmas the nonlinear dynamics and the stability are strongly affected by the initial equilibrium conditions, in particular by density and temperature gradients as well as by pressure inhomogeneities and anisotropy of the distribution functions; the aim of this work is to provide a general overview on what conditions of pressure, temperature and density can be found inside a plasma at equilibrium.
Both analytical and numerical solutions are found.
Analytical solutions are obtained for various choices of the electronic distribution function, but only in the limit of small spatial inhomogeneities. Homogeneous configurations can be found in this limit; soliton-like solutions are obtained as limiting cases of periodic solutions. Equilibria where the same magnetic field configuration is produced by different temperature and density profiles are found as well.
The solutions obtained numerically clearly show that it is possible to create a very wide variety of configurations, from periodic to isothermal
Quantum computational logic with mixed states
In this paper we solve the problem how to axiomatize a system of quantum computational gates known as the PoincarĂ© irreversible quantum computational system. A Hilbert-style calculus is introduced obtaining a strong completeness theorem.Fil: Freytes Solari, Hector Carlos. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Domenech, Graciela. Consejo Nacional de InvestigaciĂłnes CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de AstronomĂa y FĂsica del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de AstronomĂa y FĂsica del Espacio; Argentin
APP1 Transcription Is Regulated by Inositol-phosphorylceramide Synthase 1-Diacylglycerol Pathway and Is Controlled by ATF2 Transcription Factor in Cryptococcus neoformans
Inositol-phosphorylceramide synthase 1 (Ipc1) is a fungal-specific enzyme that regulates the level of two bioactive molecules, phytoceramide and diacylglycerol (DAG). In previous studies, we demonstrated that Ipc1 regulates the expression of the antiphagocytic protein 1 (App1), a novel fungal factor involved in pathogenicity of Cryptococcus neoformans. Here, we investigated the molecular mechanism by which Ipc1 regulates App1. To this end, the APP1 promoter was fused to the firefly luciferase gene in the C. neofor-mans GAL7:IPC1 strain, in which the Ipc1 expression can be modulated, and found that the luciferase activity was indeed regulated when Ipc1 was modulated. Next, using the luciferase reporter assay in both C. neoformans wild-type and GAL7:IPC1 strains, we investigated the role of DAG and sphingolipids in the activation of the APP1 promoter and found that treatment with 1,2-dioctanoylglycerol does increase APP1 transcription, whereas treatment with phytosphingosine or ceramides does not. Two putative consensus sequences were found in the APP1 promoter for ATF and AP-2 transcription factors. Mutagenesis analysis of these sequences revealed that they play a key role in the regulation of APP1 transcription: ATF is an activator, whereas AP-2 in a negative regulator. Finally, we identified a putative Atf2 transcription factor, which is required for APP1 transcription and under the control of Ipc1-DAG pathway. These studies provide novel regulatory mechanisms of the sphingolipid pathway involved in the regulation of gene transcription of C. neoformans
ASSESSING PERFORMANCE IN FORENSIC HAIR EXAMINATION: A REVIEW
Forensic biological examination is a part of forensic science, which has the aims to identify biological matrix and stains on crime scenes or findings. Forensic biological examination is important for the identification of even the smallest biological samples and their attribution to a specific person, victim or suspect. During crime scene investigation hair is one of the biological samples that can be found and can lead the operators to identify the perpetrators. In fact, hair can be easily found on findings, both clothes and objects, near victims and/or in the area of the crime. The hairs functions of protection, sensing and thermal insulation make them strongly present in almost all human population, increasing the possibility to found them quite everywhere, also on crime scenes. Microscopic analysis of the human hairs can be used to make a comparative analysis on suspects, focus the attention on pretty well-known morphological characteristics such as: medulla; scales; cortex; cuticle and pigmentation. Furthermore, the bulb of human hair, found on crime scenes or on findings, can be used in forensic genetics examination to reach a DNA matching between hairs and suspect or victim. In fact, only within the bulb there are traces of nucleated cells that let the operators to extract DNA and carry out a genetic profile. The aim of this research is to cross-compare multiple knowledge from different research papers on forensic hair examination in order to assess the evolution of the study and technology in this field and for assess new perspective of research and forensic applications
Correction: Alternatively Activated (M2) Macrophage Phenotype Is Inducible by Endothelin-1 in Cultured Human Macrophages
[This corrects the article DOI: 10.1371/journal.pone.0166433.]
Role of Sterylglucosidase 1 (Sgl1) on the pathogenicity of Cryptococcus neoformans: Potential applications for vaccine development
Cryptococcosis caused by C. neoformans and C. gattii affects a large population and is a cause of significant morbidity and mortality. Despite its public health burden, there are currently no vaccines against cryptococcosis and new strategies against such infections are needed. In this study, we demonstrate that C. neoformans has the biochemical ability to metabolize sterylglucosides (SGs), a class of immunomodulatory glycolipids. Genetic manipulations that eliminate cryptococccal sterylglucosidase lead to the accumulation of SGs and generate a mutant strain (ĂŽsgl1) that is non-pathogenic in the mouse models of cryptococcosis. Interestingly, this mutant strain acts as a vaccine strain and protects mice against cryptococcosis following infection with C. neoformans or C. gattii. The immunity induced by the ĂŽsgl1 strain is not CD4+ T-cells dependent. Immunocompromised mice, which lack CD4+ T-cells, are able to control the infection by ĂŽsgl1 and acquire immunity against the challenge by wild-type C. neoformans following vaccination with the ĂŽsgl1 strain. These findings are particularly important in the context of HIV/AIDS immune deficiency and suggest that the ĂŽsgl1 strain might provide a potential vaccination strategy against cryptococcosis
A multi-methodological approach to record dynamics and timescales of the plumbing system of Zaro (Ischia Island, Italy)
Determining the time spans of processes related to the assembly of eruptible magma at active volcanoes is fundamental to understand magma chamber dynamics and assess volcanic hazard. This information can be recorded in the chemical zoning of crystals. Nevertheless, this kind of study is still poorly employed for the active volcanoes of the Neapolitan area (Southern Italy), in particular, for Ischia island where the risk is extremely high and this information can provide the basis for probabilistic volcanic hazard assessment. For these reasons, we acquired chemical composition on clinopyroxene crystals erupted at Ischia during the Zaro eruption (6.6 ± 2.2 ka) and performed numerical simulations of the input of mafic magma into a trachytic reservoir, in order to investigate various aspects of pre-eruptive dynamics occurring at different timescales. This event emplaced a ~ 0.1 km3 lava complex, in which the main trachytic lava flows host abundant mafic to felsic enclaves. Previous petrological investigation suggested that mafic magma(s) mixed/mingled with a trachytic one, before the eruption. In this work, the clinopyroxene zoning patterns depict the growth of crystals in different magmatic environments, recording sequential changes occurred in the plumbing system before the eruption. The evolution of the plumbing system involved a hierarchy of timescales: a few hours for magma mingling caused by mafic recharge(s) and likely occurred multiple times over a decade during which a dominant magmatic environment was sustained before the eruption. Such timescales must be considered in volcanic hazard assessment at Ischia and similar active volcanoes in densely populated areas
Un settore di 'Campagna Romana' a rischio di urbanizzazione (Valle Fontana - Valle delle Campanelle; Roma; Italia centrale). Un primo inquadramento finalizzato alla tutela
We carried out a first arrangement (by field study and literature) aimed at developing a local conservation strategy. Direct and indirect evidence were collected for 53 breeding bird species (23 from the original field study), with a significant dominance of the agro-forest species, including species declining at a regional/national level (e.g., Emberiza calandra). The area was recently indicated as the subject of anthropogenic changes by urbanization. In this regard, there is an urgent need for its inclusion in the natural reserve system of RomaNatura Protected Areas
Clinical and immunological phenotypes of selective IgM deficiency in children: Results from a multicenter study
background: a few studies assessed the clinical and immunological features of selective IgM deficiency (SIgMD), especially in the pediatric age. we aimed to characterize the clinical and immunological phenotypes of a cohort of pediatric patients with SIgMD according to the different diagnostic criteria available. methods: In this multicenter study, we evaluated pediatric SIgMD patients diagnosed at the pediatric clinic in pavia, Italy, or through the Italian primary Immunodeficiency NETwork (IPINET) and monitored changes in their diagnosis over a time frame that ranges from several months to several years. results: forty-eight patients with SIgMD were included (mean serum IgM: 33 mg/dL). the most common clinical manifestations were recurrent infections (67%) and allergies (48%). subgroup analysis according to SIgMD definition criteria of the european society for Immunodeficiencies (ESID) showed no significant difference in clinical manifestations, also considering the group with additional immunological abnormalities. sixteen patients had long-term follow-up, during which 87% preserved their SIgMD diagnosis, while two patients showed a reduction in IgA in addition to low IgM. conclusions: our data suggest that the identification of a reduction in serum IgM in children should lead to a complete immunological work-up to obtain a comprehensive clinical and immunological characterization of the patient. the follow-up of these patients is fundamental to define the disease evolution and appropriate management
Draft genome sequences of six listeria monocytogenes strains isolated from dairy products from a processing plant in Southern Italy
Here we announce the draft genome sequences of 6 Listeria monocytogenes strains from ricotta cheese produced in a dairy processing plant located in southern Italy and potentially involved in a multistate outbreak of listeriosis in the United States
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