955 resultados para Self-Abasement Complex
Resumo:
The intracellular location of nucleic acid sensors prevents recognition of extracellular self-DNA released by dying cells. However, on forming a complex with the endogenous antimicrobial peptide LL37, extracellular DNA is transported into endosomal compartments of plasmacytoid dendritic cells, leading to activation of Toll-like receptor-9 and induction of type I IFNs. Whether LL37 also transports self-DNA into nonplasmacytoid dendritic cells, leading to type I IFN production via other intracellular DNA receptors is unknown. Here we found that LL37 very efficiently transports self-DNA into monocytes, leading the production of type I IFNs in a Toll-like receptor-independent manner. This type I IFN induction was mediated by double-stranded B form DNA, regardless of its sequence, CpG content, or methylation status, and required signaling through the adaptor protein STING and TBK1 kinase, indicating the involvement of cytosolic DNA sensors. Thus, our study identifies a novel link between the antimicrobial peptides and type I IFN responses involving DNA-dependent activation of cytosolic sensors in monocytes.
Resumo:
Suicide by self-poisoning is rather common around the world. This paper presents an exceptional complex suicide in which nicotine was applied in the form of self-made patches soaked with an extraction from fine-cut tobacco. In addition, the 51-year-old suicide victim took a lethal dose of diphenhydramine. Toxicological analysis also revealed the presence of tetrazepam in subtherapeutic concentrations. The scene of death suggested an autoerotic accident at first, as the body was tied with tapes, cables and handcuffs. As a result of the entire investigations, the fatality had to be classified as a suicidal intoxication by nicotine and diphenhydramine.
Resumo:
We uncover the global organization of clustering in real complex networks. To this end, we ask whether triangles in real networks organize as in maximally random graphs with given degree and clustering distributions, or as in maximally ordered graph models where triangles are forced into modules. The answer comes by way of exploring m-core landscapes, where the m-core is defined, akin to the k-core, as the maximal subgraph with edges participating in at least m triangles. This property defines a set of nested subgraphs that, contrarily to k-cores, is able to distinguish between hierarchical and modular architectures. We find that the clustering organization in real networks is neither completely random nor ordered although, surprisingly, it is more random than modular. This supports the idea that the structure of real networks may in fact be the outcome of self-organized processes based on local optimization rules, in contrast to global optimization principles.
Resumo:
Dissolved organic matter (DOM) is a complex mixture of organic compounds, ubiquitous in marine and freshwater systems. Fluorescence spectroscopy, by means of Excitation-Emission Matrices (EEM), has become an indispensable tool to study DOM sources, transport and fate in aquatic ecosystems. However the statistical treatment of large and heterogeneous EEM data sets still represents an important challenge for biogeochemists. Recently, Self-Organising Maps (SOM) has been proposed as a tool to explore patterns in large EEM data sets. SOM is a pattern recognition method which clusterizes and reduces the dimensionality of input EEMs without relying on any assumption about the data structure. In this paper, we show how SOM, coupled with a correlation analysis of the component planes, can be used both to explore patterns among samples, as well as to identify individual fluorescence components. We analysed a large and heterogeneous EEM data set, including samples from a river catchment collected under a range of hydrological conditions, along a 60-km downstream gradient, and under the influence of different degrees of anthropogenic impact. According to our results, chemical industry effluents appeared to have unique and distinctive spectral characteristics. On the other hand, river samples collected under flash flood conditions showed homogeneous EEM shapes. The correlation analysis of the component planes suggested the presence of four fluorescence components, consistent with DOM components previously described in the literature. A remarkable strength of this methodology was that outlier samples appeared naturally integrated in the analysis. We conclude that SOM coupled with a correlation analysis procedure is a promising tool for studying large and heterogeneous EEM data sets.
Resumo:
Poly(ß,L-malic acid) (PMLA) was made to interact with the cationic anticancer drug Doxorubicin (DOX) in aqueous solution to form ionic complexes with different compositions and an efficiency near to 100%. The PMLA/DOX complexes were characterized by spectroscopy, thermal analysis, and scanning electron microscopy. According to their composition, the PMLA/DOX complexes spontaneously self-assembled into spherical micro or nanoparticles with negative surface charge. Hydrolytic degradation of PMLA/DOX complexes took place by cleavage of the main chain ester bond and simultaneous release of the drug. In vitro drug release studies revealed that DOX delivery from the complexes was favored by acidic pH and high ionic strength
Resumo:
Adipose tissue (AT) is distributed as large differentiated masses, and smaller depots covering vessels, and organs, as well as interspersed within them. The differences between types and size of cells makes AT one of the most disperse and complex organs. Lipid storage is partly shared by other tissues such as muscle and liver. We intended to obtain an approximate estimation of the size of lipid reserves stored outside the main fat depots. Both male and female rats were made overweight by 4-weeks feeding of a cafeteria diet. Total lipid content was analyzed in brain, liver, gastrocnemius muscle, four white AT sites: subcutaneous, perigonadal, retroperitoneal and mesenteric, two brown AT sites (interscapular and perirenal) and in a pool of the rest of organs and tissues (after discarding gut contents). Organ lipid content was estimated and tabulated for each individual rat. Food intake was measured daily. There was a surprisingly high proportion of lipid not accounted for by the main macroscopic AT sites, even when brain, liver and BAT main sites were discounted. Muscle contained about 8% of body lipids, liver 1-1.4%, four white AT sites lipid 28-63% of body lipid, and the rest of the body (including muscle) 38-44%. There was a good correlation between AT lipid and body lipid, but lipid in"other organs" was highly correlated too with body lipid. Brain lipid was not. Irrespective of dietary intake, accumulation of body fat was uniform both for the main lipid storage and handling organs: large masses of AT (but also liver, muscle), as well as in the"rest" of tissues. These storage sites, in specialized (adipose) or not-specialized (liver, muscle) tissues reacted in parallel against a hyperlipidic diet challenge. We postulate that body lipid stores are handled and regulated coordinately, with a more centralized and overall mechanisms than usually assumed.
Resumo:
Dissolved organic matter (DOM) is a complex mixture of organic compounds, ubiquitous in marine and freshwater systems. Fluorescence spectroscopy, by means of Excitation-Emission Matrices (EEM), has become an indispensable tool to study DOM sources, transport and fate in aquatic ecosystems. However the statistical treatment of large and heterogeneous EEM data sets still represents an important challenge for biogeochemists. Recently, Self-Organising Maps (SOM) has been proposed as a tool to explore patterns in large EEM data sets. SOM is a pattern recognition method which clusterizes and reduces the dimensionality of input EEMs without relying on any assumption about the data structure. In this paper, we show how SOM, coupled with a correlation analysis of the component planes, can be used both to explore patterns among samples, as well as to identify individual fluorescence components. We analysed a large and heterogeneous EEM data set, including samples from a river catchment collected under a range of hydrological conditions, along a 60-km downstream gradient, and under the influence of different degrees of anthropogenic impact. According to our results, chemical industry effluents appeared to have unique and distinctive spectral characteristics. On the other hand, river samples collected under flash flood conditions showed homogeneous EEM shapes. The correlation analysis of the component planes suggested the presence of four fluorescence components, consistent with DOM components previously described in the literature. A remarkable strength of this methodology was that outlier samples appeared naturally integrated in the analysis. We conclude that SOM coupled with a correlation analysis procedure is a promising tool for studying large and heterogeneous EEM data sets.
Resumo:
Self-organization is a growing interdisciplinary field of research about a phenomenon that can be observed in the Universe, in Nature and in social contexts. Research on self-organization tries to describe and explain forms, complex patterns and behaviours that arise from a collection of entities without an external organizer. As researchers in artificial systems, our aim is not to mimic self-organizing phenomena arising in Nature, but to understand and to control underlying mechanisms allowing desired emergence of forms, complex patterns and behaviours. Rather than attempting to eliminate such self-organization in artificial systems, we think that this might be deliberately harnessed in order to reach desirable global properties. In this paper we analyze three forms of self-organization: stigmergy, reinforcement mechanisms and cooperation. The amplification phenomena founded in stigmergic process or in reinforcement process are different forms of positive feedbacks that play a major role in building group activity or social organization. Cooperation is a functional form for self-organization because of its ability to guide local behaviours in order to obtain a relevant collective one. For each forms of self-organisation, we present a case study to show how we transposed it to some artificial systems and then analyse the strengths and weaknesses of such an approach
Resumo:
A new Cu(II) trimers, [Cu3(dcp)2(H2O)8]. 4DMF, with the ligand 3,5-pyrazoledicarboxylic acid monohydrate (H3dcp) has been prepared by solvent method. Its solid-state structure has been characterized by elemental analysis, thermal analysis (TGA and DSC), and single crystal X-ray diffraction. X-ray crystallographic studies reveal that this complex has extended 1-D,2-D and 3-D supramolecular architectures directed by weak interactions (hydrogen bond and aromatic π-π stacking interaction) leading to a sandwich solid-state structure.
Resumo:
Systems biology is a new, emerging and rapidly developing, multidisciplinary research field that aims to study biochemical and biological systems from a holistic perspective, with the goal of providing a comprehensive, system- level understanding of cellular behaviour. In this way, it addresses one of the greatest challenges faced by contemporary biology, which is to compre- hend the function of complex biological systems. Systems biology combines various methods that originate from scientific disciplines such as molecu- lar biology, chemistry, engineering sciences, mathematics, computer science and systems theory. Systems biology, unlike “traditional” biology, focuses on high-level concepts such as: network, component, robustness, efficiency, control, regulation, hierarchical design, synchronization, concurrency, and many others. The very terminology of systems biology is “foreign” to “tra- ditional” biology, marks its drastic shift in the research paradigm and it indicates close linkage of systems biology to computer science. One of the basic tools utilized in systems biology is the mathematical modelling of life processes tightly linked to experimental practice. The stud- ies contained in this thesis revolve around a number of challenges commonly encountered in the computational modelling in systems biology. The re- search comprises of the development and application of a broad range of methods originating in the fields of computer science and mathematics for construction and analysis of computational models in systems biology. In particular, the performed research is setup in the context of two biolog- ical phenomena chosen as modelling case studies: 1) the eukaryotic heat shock response and 2) the in vitro self-assembly of intermediate filaments, one of the main constituents of the cytoskeleton. The range of presented approaches spans from heuristic, through numerical and statistical to ana- lytical methods applied in the effort to formally describe and analyse the two biological processes. We notice however, that although applied to cer- tain case studies, the presented methods are not limited to them and can be utilized in the analysis of other biological mechanisms as well as com- plex systems in general. The full range of developed and applied modelling techniques as well as model analysis methodologies constitutes a rich mod- elling framework. Moreover, the presentation of the developed methods, their application to the two case studies and the discussions concerning their potentials and limitations point to the difficulties and challenges one encounters in computational modelling of biological systems. The problems of model identifiability, model comparison, model refinement, model inte- gration and extension, choice of the proper modelling framework and level of abstraction, or the choice of the proper scope of the model run through this thesis.
Resumo:
The goal of this paper was to test the presence of mimicry in Asclepias curassavica L., Epidendrum fulgens Brong., and Lantana camara L. The study was carried out at the Parque Estadual de Itapeva, RS, southern Brazil, from 2004 to 2006. Flowering period of each of the three species was followed up; focal observations of butterflies visiting flowers, from fixed point and during random walks were carried out. We also estimated the frequency of pollinaria removal in the orchid, as well as its mode of reproduction. All these variables were important for testing the mimicry hypothesis. Despite some temporal coincidences in the flowering period of two plants in the system, there was no statistical association among the three plants as to flowering period. Twenty-nine species of butterflies, as potential pollinators, were recorded, particularly Agraulis vanillae maculosa, Dryas iulia alcionea, Urbanus simplicius, Tegosa claudina, and Heliconius erato phyllis, which were the more frequent visitors of the three plants. There was association between the number of visits to L. camara and E. fulgens, based on Pearson correlation (r = 0.4603; n = 19; P = 0.0473). Pollinaria removal of E. fulgens was low, as measured by the percentage of removal (range: 0 - 10%). The analysis of the mode of reproduction of this orchid showed its pollinator-dependence, since no fruits were formed by spontaneous self-pollination. In contrast, the percentage of fruit set that resulted from geitonogamy and xenogamy was, in average, 86%. The results here shown are not conclusive as to the occurrence of a mimicry system among the three plants.
Resumo:
Business intelligence (BI) is an information process that includes the activities and applications used to transform business data into valuable business information. Today’s enterprises are collecting detailed data which has increased the available business data drastically. In order to meet changing customer needs and gain competitive advantage businesses try to leverage this information. However, IT departments are struggling to meet the increased amount of reporting needs. Therefore, recent shift in the BI market has been towards empowering business users with self-service BI capabilities. The purpose of this study was to understand how self-service BI could help businesses to meet increased reporting demands. The research problem was approached with an empirical single case study. Qualitative data was gathered with a semi-structured, theme-based interview. The study found out that case company’s BI system was mostly used for group performance reporting. Ad-hoc and business user-driven information needs were mostly fulfilled with self-made tools and manual work. It was felt that necessary business information was not easily available. The concept of self-service BI was perceived to be helpful to meet such reporting needs. However, it was found out that the available data is often too complex for an average user to fully understand. The respondents felt that in order to self-service BI to work, the data has to be simplified and described in a way that it can be understood by the average business user. The results of the study suggest that BI programs struggle in meeting all the information needs of today’s businesses. The concept of self-service BI tries to resolve this problem by allowing users easy self-service access to necessary business information. However, business data is often complex and hard to understand. Self-serviced BI has to overcome this challenge before it can reach its potential benefits.
Resumo:
Business intelligence (BI) is an information process that includes the activities and applications used to transform business data into valuable business information. Today’s enterprises are collecting detailed data which has increased the available business data drastically. In order to meet changing customer needs and gain competitive advantage businesses try to leverage this information. However, IT departments are struggling to meet the increased amount of reporting needs. Therefore, recent shift in the BI market has been towards empowering business users with self-service BI capabilities. The purpose of this study was to understand how self-service BI could help businesses to meet increased reporting demands. The research problem was approached with an empirical single case study. Qualitative data was gathered with a semi-structured, theme-based interview. The study found out that case company’s BI system was mostly used for group performance reporting. Ad-hoc and business user-driven information needs were mostly fulfilled with self-made tools and manual work. It was felt that necessary business information was not easily available. The concept of self-service BI was perceived to be helpful to meet such reporting needs. However, it was found out that the available data is often too complex for an average user to fully understand. The respondents felt that in order to self-service BI to work, the data has to be simplified and described in a way that it can be understood by the average business user. The results of the study suggest that BI programs struggle in meeting all the information needs of today’s businesses. The concept of self-service BI tries to resolve this problem by allowing users easy self-service access to necessary business information. However, business data is often complex and hard to understand. Self-serviced BI has to overcome this challenge before it can reach its potential benefits.
Resumo:
This study performed a aecondvy dau analysis of information collected during the Youth Leisure Study (YLS). The purpose of this study was to examine the potential moderating influences of gender and general self-efTicacy on the relationships aoKXig sensation-seeking and various forms of substance use in adolescents. Specifically, the predictive ability of sensation seeking on five adolescents substance use outcomes (alcohol, tobacco, and marijuana use; binge drinking; and number of times drunk) was examined. Moderated hierarchical multiple regression (MHMR) analyses were used to examine the relationships among study variables. The results for this study indicate that the relationships among sensation-seeking and forms of adolescent substance use are more complex than literature suggests. Main effect relationships were found consistently for sensation-seeking and general self-efficacy with each of the outcome variables. Results for gender were not consistent across the substance use outcomes. Gender was a significant predictor for marijuana use only. The moderating effects of general self-efficacy (GSE) on the sensation-seekingsubstance use relationship were inconsistent. While no significant interactions were found for tobacco or alcohol use outcomes, GSE was found to moderate the relationship between sensation-seeking and marijuana use indicating that feelings of high general selfefficacy act as a buffer or guard against marijuana use. A consistent pattern was found among the alcohol use variables (alcohol use. binge drinking, and number of times drunk). Gender was found to moderate each of these variables indicating that higher levels of sensation seeking are more predictive of higher levels of adolescent alcohol use in males only. Implications of this study on the field of education, are discussed further, and suggestions for future research are presented.
Resumo:
This qualitative phenomenological investigation explored six female Master of Education students' critical understandings of their identity and role negotiations, and their perceptions of environmental conditions that facilitated or impeded their identity explorations and negotiations within the institution. The interweaving of Feminist and Women's Development theories enabled the data to be examined under different, yet complementary, lenses. The data collection strategies included: four to five in-depth semistructured interviews, three take-home activities (involving identity mapping, object and metaphor identification, and strategy development), and the compilation of extensive interview notes as well as researcher reflections. The combination of a constant comparative method and a voice-centered method were used in tandem to analyze the data. Together they uncovered five emergent themes: (a) intricate understandings of key terms; (b) life-long learning and transformative pathways; (c) gender issues; (d) challenges, tensions, and possibilities; as well as (e) personal, professional, and educational implications. The findings underscored the possibility for both a singular static identity and dynamic multifaceted identities to exist in tandem, and the emergence of natural or logical identity intersections, as well as disjointed or colliding identity intersections. Ultimately, it is the continuous negotiation of internal and external spheres that contributes to the complexity and multidimensionality of graduate students' identities.