Candida albicans stimulates in vivo differentiation of haematopoietic stem and progenitor cells towards macrophages by a TLR2-dependent signalling

Toll-like receptors (TLRs) are expressed by haematopoietic stem and progenitor cells (HSPCs), and may play a role in haematopoiesis in response to pathogens during infection. We have previously demonstrated that (i) inactivated yeasts of Candida albicans induce in vitro differentiation of HSPCs towards the myeloid lineage, and (ii) soluble TLR agonists induce in vivo their differentiation towards macrophages. In this work, using an in vivo model of HSPCs transplantation, we report for the first time that HSPCs sense C. albicans in vivo and subsequently are directed to produce macrophages by a TLR2-dependent signalling. Purified lineage-negative cells (Lin−) from bone marrow of C57BL/6 mice (CD45.2 alloantigen) were transplanted into B6Ly5.1 mice (CD45.1 alloantigen), which were then injected with viable or inactivated C. albicans yeasts. Transplanted cells were detected in the spleen and in the bone marrow of recipient mice, and they differentiate preferentially to macrophages, both in response to infection or in response to inactivated yeasts. The generation of macrophages was dependent on TLR2 but independent of TLR4, as transplanted Lin− cells from TLR2−/− mice did not give rise to macrophages, whereas Lin− cells from TLR4−/− mice generated macrophages similarly to control cells. Interestingly, the absence of TLR2, or in a minor extent TLR4, gives Lin− cells an advantage in transplantation assays, as increases the percentage of transplanted recovered cells. Our results indicatethat TLR-mediated recognition of C. albicans by HSPCs may help replace and/or increase cells that constitute the first line of defence against the fungus, and suggest that TLR-mediated signalling may lead to reprogramming early progenitors to rapidly replenishing the innate immune system and generate the most necessary mature cells to deal with the pathogen.

Application of Text Summarization techniques to the Geographical Information Retrieval task

Automatic Text Summarization has been shown to be useful for Natural Language Processing tasks such as Question Answering or Text Classification and other related fields of computer science such as Information Retrieval. Since Geographical Information Retrieval can be considered as an extension of the Information Retrieval field, the generation of summaries could be integrated into these systems by acting as an intermediate stage, with the purpose of reducing the document length. In this manner, the access time for information searching will be improved, while at the same time relevant documents will be also retrieved. Therefore, in this paper we propose the generation of two types of summaries (generic and geographical) applying several compression rates in order to evaluate their effectiveness in the Geographical Information Retrieval task. The evaluation has been carried out using GeoCLEF as evaluation framework and following an Information Retrieval perspective without considering the geo-reranking phase commonly used in these systems. Although single-document summarization has not performed well in general, the slight improvements obtained for some types of the proposed summaries, particularly for those based on geographical information, made us believe that the integration of Text Summarization with Geographical Information Retrieval may be beneficial, and consequently, the experimental set-up developed in this research work serves as a basis for further investigations in this field.

Towards automatic tweet generation: A comparative study from the text summarization perspective in the journalism genre

In recent years, Twitter has become one of the most important microblogging services of the Web 2.0. Among the possible uses it allows, it can be employed for communicating and broadcasting information in real time. The goal of this research is to analyze the task of automatic tweet generation from a text summarization perspective in the context of the journalism genre. To achieve this, different state-of-the-art summarizers are selected and employed for producing multi-lingual tweets in two languages (English and Spanish). A wide experimental framework is proposed, comprising the creation of a new corpus, the generation of the automatic tweets, and their assessment through a quantitative and a qualitative evaluation, where informativeness, indicativeness and interest are key criteria that should be ensured in the proposed context. From the results obtained, it was observed that although the original tweets were considered as model tweets with respect to their informativeness, they were not among the most interesting ones from a human viewpoint. Therefore, relying only on these tweets may not be the ideal way to communicate news through Twitter, especially if a more personalized and catchy way of reporting news wants to be performed. In contrast, we showed that recent text summarization techniques may be more appropriate, reflecting a balance between indicativeness and interest, even if their content was different from the tweets delivered by the news providers.

Tailoring the Surface Chemistry of Activated Carbon Cloth by Electrochemical Methods

This paper presents a systematic study of the effect of the electrochemical treatment (galvanostatic electrolysis in a filter-press electrochemical cell) on the surface chemistry and porous texture of commercial activated carbon cloth. The same treatments have been conducted over a granular activated carbon in order to clarify the effect of morphology. The influence of different electrochemical variables, such as the electrode polarity (anodic or cathodic), the applied current (between 0.2 and 1.0 A) and the type of electrolyte (HNO3 and NaCl) have also been analyzed. The anodic treatment of both activated carbons causes an increase in the amount of surface oxygen groups, whereas the cathodic treatment does not produce any relevant modification of the surface chemistry. The HNO3 electrolyte produced a lower generation of oxygen groups than the NaCl one, but differences in the achieved distribution of surface groups can be benefitial to selectively tune the surface chemistry. The porous texture seems to be unaltered after the electro-oxidation treatment. The validity of this method to introduce surface oxygen groups with a pseudocapacitive behavior has been corroborated by cyclic voltammetry. As a conclusion, the electrochemical treatment can be easily implemented to selectively and quantitatively modify the surface chemistry of activated carbons with different shapes and morphologies.

Role of IFN-gamma in immune responses to Candida albicans infections

Candida albicans is the most frequent etiologic agent that causes opportunistic fungal infections called candidiasis, a disease whose systemic manifestation could prove fatal and whose incidence is increasing as a result of an expanding immunocompromised population. Here we review the role of interferon-gamma (IFN-γ) in host protection against invasive candidiasis. This cytokine plays an essential role in both the innate and adaptive arms of the immune response to candidiasis. We focus on recent progress on host-pathogen interactions leading to the production of IFN-γ by host cells. IFN-γ is produced by CD4 Th1, CD8, γδ T, and natural killer (NK) cells, essentially in response to both IL-12 and/or IL-18; more recently, a subset of C. albicans-specific Th17 cells have been described to produce both IL-17 and IFN-γ. IFN-γ plays an important role in the regulation of the immune system as well as in the control of the infectious process, as it is required for optimal activation of phagocytes, collaborates in the generation of protective antibody response, and favors the development of a Th1 protective response.

Syntactic and Semantic Relationships in Models of Complex Systems: An Ecological Case

In this paper, the authors extend and generalize the methodology based on the dynamics of systems with the use of differential equations as equations of state, allowing that first order transformed functions not only apply to the primitive or original variables, but also doing so to more complex expressions derived from them, and extending the rules that determine the generation of transformed superior to zero order (variable or primitive). Also, it is demonstrated that for all models of complex reality, there exists a complex model from the syntactic and semantic point of view. The theory is exemplified with a concrete model: MARIOLA model.

Enhanced electro-oxidation resistance of carbon electrodes induced by phosphorus surface groups

The electro-oxidation of carbon materials enormously degrades their performance and limits their wider utilization in multiple electrochemical applications. In this work, the positive influence of phosphorus functionalities on the overall electrochemical stability of carbon materials has been demonstrated under different conditions. We show that the extent and selectivity of electroxidation in P-containing carbons are completely different to those observed in conventional carbons without P. The electro-oxidation of P-containing carbons involves the active participation of phosphorus surface groups, which are gradually transformed at high potentials from less-to more-oxidized species to slow down the introduction of oxygen groups on the carbon surface (oxidation) and the subsequent generation of (C*OOH)-like unstable promoters of electro-gasification. The highest-oxidized P groups (–C–O–P-like species) seem to distribute the gained oxygen to neighboring carbon sites, which finally suffer oxidation and/or gasification. So it is thought that P-groups could act as mediators of carbon oxidation although including various steps and intermediates compared to electroxidation in P-free materials.

An Acyl-NHC Osmium Cooperative System: Coordination of Small Molecules and Heterolytic B–H and O–H Bond Activation

The hexahydride complex OsH6(PiPr3)2 (1) activates the C–OMe bond of 1-(2-methoxy-2-oxoethyl)-3-methylimidazolium chloride (2), in addition to promoting the direct metalation of the imidazolium group, to afford a five-coordinate OsCl(acyl-NHC)(PiPr3)2 (3) compound. The latter coordinates carbon monoxide, oxygen, and molecular hydrogen to give the corresponding carbonyl (4), dioxygen (5), and dihydrogen (6) derivatives. Complex 3 also promotes the heterolytic bond activation of pinacolborane (HBpin), using the acyl oxygen atom as a pendant Lewis base. The hydride ligand and the Bpin substituent of the Fischer-type carbene of the resulting complex 7 activate the O–H bond of alcohols and water. As a consequence, complex 3 is a metal ligand cooperating catalyst for the generation of molecular hydrogen, by means of both the alcoholysis and hydrolysis of pinacolborane, via the intermediates 7 and 6.

Simulation of the secondary electrons energy deposition produced by proton beams in PMMA: influence of the target electronic excitation description

We have studied the radial dependence of the energy deposition of the secondary electron generated by swift proton beams incident with energies T = 50 keV–5 MeV on poly(methylmethacrylate) (PMMA). Two different approaches have been used to model the electronic excitation spectrum of PMMA through its energy loss function (ELF), namely the extended-Drude ELF and the Mermin ELF. The singly differential cross section and the total cross section for ionization, as well as the average energy of the generated secondary electrons, show sizeable differences at T ⩽ 0.1 MeV when evaluated with these two ELF models. In order to know the radial distribution around the proton track of the energy deposited by the cascade of secondary electrons, a simulation has been performed that follows the motion of the electrons through the target taking into account both the inelastic interactions (via electronic ionizations and excitations as well as electron-phonon and electron trapping by polaron creation) and the elastic interactions. The radial distribution of the energy deposited by the secondary electrons around the proton track shows notable differences between the simulations performed with the extended-Drude ELF or the Mermin ELF, being the former more spread out (and, therefore, less peaked) than the latter. The highest intensity and sharpness of the deposited energy distributions takes place for proton beams incident with T ~ 0.1–1 MeV. We have also studied the influence in the radial distribution of deposited energy of using a full energy distribution of secondary electrons generated by proton impact or using a single value (namely, the average value of the distribution); our results show that differences between both simulations become important for proton energies larger than ~0.1 MeV. The results presented in this work have potential applications in materials science, as well as hadron therapy (due to the use of PMMA as a tissue phantom) in order to properly consider the generation of electrons by proton beams and their subsequent transport and energy deposition through the target in nanometric scales.

A Novel Prediction Method for Early Recognition of Global Human Behaviour in Image Sequences

Human behaviour recognition has been, and still remains, a challenging problem that involves different areas of computational intelligence. The automated understanding of people activities from video sequences is an open research topic in which the computer vision and pattern recognition areas have made big efforts. In this paper, the problem is studied from a prediction point of view. We propose a novel method able to early detect behaviour using a small portion of the input, in addition to the capabilities of it to predict behaviour from new inputs. Specifically, we propose a predictive method based on a simple representation of trajectories of a person in the scene which allows a high level understanding of the global human behaviour. The representation of the trajectory is used as a descriptor of the activity of the individual. The descriptors are used as a cue of a classification stage for pattern recognition purposes. Classifiers are trained using the trajectory representation of the complete sequence. However, partial sequences are processed to evaluate the early prediction capabilities having a specific observation time of the scene. The experiments have been carried out using the three different dataset of the CAVIAR database taken into account the behaviour of an individual. Additionally, different classic classifiers have been used for experimentation in order to evaluate the robustness of the proposal. Results confirm the high accuracy of the proposal on the early recognition of people behaviours.

Group-Based Symptom Trajectories in Indicated Prevention of Adolescent Depression

Background: Adolescent depression prevention research has focused on mean intervention outcomes, but has not considered heterogeneity in symptom course. Here, we empirically identify subgroups with distinct trajectories of depressive symptom change among adolescents enrolled in two indicated depression preven- tion trials and examine how cognitive-behavioral (CB) interventions and baseline predictors relate to trajectory membership. Methods: Six hundred thirty-one participants were assigned to one of three conditions: CB group intervention, CB bibliotherapy, and brochure control. We used group-based trajectory modeling to identify trajectories of depressive symptoms from pretest to 2-year follow-up. We examined associations between class membership and conditions using chi- square tests and baseline predictors using multinomial regressions. Results: We identified four trajectories in the full sample. Qualitatively similar trajectories were found in each condition separately. Two trajectories of positive symptom course (low-declining, high-declining) had declining symptoms and were dis- tinguished by baseline symptom severity. Two trajectories of negative course (high-persistent, resurging), respectively, showed no decline in symptoms or de- cline followed by symptom reappearance. Participants in the brochure control condition were significantly more likely to populate the high-persistent trajectory relative to either CB condition and were significantly less likely to populate the low-declining trajectory relative to CB group. Several baseline factors predicted trajectory classes, but gender was the most informative prognostic factor, with males having increased odds of membership in a high-persistent trajectory rel- ative to other trajectories. Conclusions: Findings suggest that CB preventive interventions do not alter the nature of trajectories, but reduce the risk that adolescents follow a trajectory of chronically elevated symptoms.

Group-Based Symptom Trajectories in Indicated Prevention of Adolescent Depression

Background: Adolescent depression prevention research has focused on mean intervention outcomes, but has not considered heterogeneity in symptom course. Here, we empirically identify subgroups with distinct trajectories of depressive symptom change among adolescents enrolled in two indicated depression preven- tion trials and examine how cognitive-behavioral (CB) interventions and baseline predictors relate to trajectory membership. Methods: Six hundred thirty-one participants were assigned to one of three conditions: CB group intervention, CB bibliotherapy, and brochure control. We used group-based trajectory modeling to identify trajectories of depressive symptoms from pretest to 2-year follow-up. We examined associations between class membership and conditions using chi- square tests and baseline predictors using multinomial regressions. Results: We identified four trajectories in the full sample. Qualitatively similar trajectories were found in each condition separately. Two trajectories of positive symptom course (low-declining, high-declining) had declining symptoms and were dis- tinguished by baseline symptom severity. Two trajectories of negative course (high-persistent, resurging), respectively, showed no decline in symptoms or de- cline followed by symptom reappearance. Participants in the brochure control condition were significantly more likely to populate the high-persistent trajectory relative to either CB condition and were significantly less likely to populate the low-declining trajectory relative to CB group. Several baseline factors predicted trajectory classes, but gender was the most informative prognostic factor, with males having increased odds of membership in a high-persistent trajectory rel- ative to other trajectories. Conclusions: Findings suggest that CB preventive interventions do not alter the nature of trajectories, but reduce the risk that adolescents follow a trajectory of chronically elevated symptoms.

Study of plutonium oxide heat generation in a wood moderated container /

The generation of heat due to the radioactive decay of plutonium in the form of plutonium dioxide stored in wooden containers is considered. The results of two experiments in which plutonium dioxide is placed inside wooden blocks and the temperature rise measured at various points is reported. Heat transfer calculations are then performed to show that the data obtained are those which would be expected, i.e., that Fourier's Law adequately describes the situation. The heat build up in a proposed wood moderated shipping container is calculated, using some of the assumptions verified in the described experiments.

Educational Systems for Maximizing Learning Online and in the Classroom

Thesis (Ph.D.)--University of Washington, 2016-06

Communicative practices in online communication: A case of agreeing to disagree

Online communities have evolved beyond the realm of social phenomenon to become important knowledge-sharing media with real economic consequences. However, the sharing of knowledge and the communication of meaning through Internet technology presents many difficulties. This is particularly so for online finance forums where market-sensitive information and disinformation about exchange-traded stocks is regularly disseminated. The development of trust and the effect of misinformation in this environment are important in the growth of this communication medium. Forum administrators need to better understand and handle the development of trust. In this article, we analyze and discuss the communicative practices of a group of investors and members of an online community of interest. We found that conflict as a driver of knowledge sharing is an important consideration for forum administrators and designers.