5,040 research outputs found
Aperiodic String Transducers
Regular string-to-string functions enjoy a nice triple characterization
through deterministic two-way transducers (2DFT), streaming string transducers
(SST) and MSO definable functions. This result has recently been lifted to FO
definable functions, with equivalent representations by means of aperiodic 2DFT
and aperiodic 1-bounded SST, extending a well-known result on regular
languages. In this paper, we give three direct transformations: i) from
1-bounded SST to 2DFT, ii) from 2DFT to copyless SST, and iii) from k-bounded
to 1-bounded SST. We give the complexity of each construction and also prove
that they preserve the aperiodicity of transducers. As corollaries, we obtain
that FO definable string-to-string functions are equivalent to SST whose
transition monoid is finite and aperiodic, and to aperiodic copyless SST
Modelling the chemical recycling of crosslinked poly (methyl methacrylate): kinetics of depolymerisation
Whereas increasing plastic solid waste production constitutes one of the main challenges of modern society, mainly due to the lack of suitable recycling technologies, chemical recycling represents an attractive solution for the conversion of plastic solid waste into valuable chemical intermediates. Herein, a kinetic model for the pyrolysis of a dental industry waste, ethylene glycol dimethacrylate (EGDMA) crosslinked poly (methyl methacrylate) (PMMA), is presented for the first time. Kinetics parameters and their statistical significance have been estimated from eight non-isothermal thermogravimetric analysis (TGA) experiments with heating rates varying between 5 and 50 °C·min-1 by using nonlinear regression. Our analysis indicates that the mechanism of depolymerisation of EGDMA crosslinked PMMA is likely to involve a consecutive reaction pathway involving two steps. The developed kinetic model - containing five kinetic parameters only - was able to predict well all non-isothermal TGA runs, and was validated against isothermal TGA experiments at 400 °C
Sterol O-Acyltransferase 1 (SOAT1, ACAT) Is a Novel Target of Steroidogenic Factor-1 (SF-1, NR5A1, Ad4BP) in the Human Adrenal
Context: Steroidogenic factor-1 (SF-1, NR5A1, Ad4BP) is a master regulator of adrenal development and steroidogenesis. Defects in several known targets of SF-1 can cause adrenal disorders in humans.Objective: We aimed to identify novel targets of SF-1 in the human adrenal. These factors could be important regulators of adrenal development and steroidogenesis and potential candidates for adrenal dysfunction.Design: A gene discovery strategy was developed based on bidirectional manipulation of SF-1. Overexpression or knockdown of SF-1 in NCI-H295R human adrenocortical cells was used to identify a subset of positively-regulated SF-1 targets.Results: This approach identified well-established SF-1 target genes (STAR, CYP11A) and several novel genes (VSNL1, ZIM2, PEG3, SOAT1, and MTSS1). Given its role in cholesterol metabolism, sterol O-acyltransferase 1 (SOAT1, previously referred to as acyl-Coenzyme A: cholesterol acyltransferase 1, ACAT) was studied further and found to be expressed in the developing human fetal adrenal cortex. We hypothesized that impaired SOAT1 activity could result in adrenal insufficiency through reduced cholesteryl ester reserves or through toxic destruction of the adrenal cells during development. Therefore, mutational analysis of SOAT1 in a cohort of 43 patients with unexplained adrenal insufficiency was performed but failed to reveal significant coding sequence changes.Conclusions: Our reverse discovery approach led to the identification of novel SF-1 targets and defined SOAT1 as an important factor in human adrenal steroidogenesis. SF-1-dependent upregulation of SOAT1 may be important for maintaining readily-releasable cholesterol reserves needed for active steroidogenesis and during episodes of recurrent stress. (J Clin Endocrinol Metab 96: E663-E668, 2011
Contribution of microscopy for understanding the mechanism of action against trypanosomatids
Transmission electron microscopy (TEM) has proved to be a useful tool to study the ultrastructural alterations and the target organelles of new antitrypanosomatid drugs. Thus, it has been observed that sesquiterpene lactones induce diverse ultrastructural alterations in both T. cruzi and Leishmania spp., such as cytoplasmic vacuolization, appearance of multilamellar structures, condensation of nuclear DNA, and, in some cases, an important accumulation of lipid vacuoles. This accumulation could be related to apoptotic events. Some of the sesquiterpene lactones (e.g., psilostachyin) have also been demonstrated to cause an intense mitochondrial swelling accompanied by a visible kinetoplast deformation as well as the appearance of multivesicular bodies. This mitochondrial swelling could be related to the generation of oxidative stress and associated to alterations in the ergosterol metabolism. The appearance of multilamellar structures and multiple kinetoplasts and flagella induced by the sesquiterpene lactone psilostachyin C indicates that this compound would act at the parasite cell cycle level, in an intermediate stage between kinetoplast segregation and nuclear division. In turn, the diterpene lactone icetexane has proved to induce the external membrane budding on T. cruzi together with an apparent disorganization of the pericellar cytoskeleton. Thus, ultrastructural TEM studies allow elucidating the possible mechanisms and the subsequent identification of molecular targets for the action of natural compounds on trypanosomatids.Fil: Lozano, Esteban Sebastián. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mendoza. Instituto de Medicina y BiologĂa Experimental de Cuyo; ArgentinaFil: Spina Zapata, Renata MarĂa. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mendoza. Instituto de HistologĂa y EmbriologĂa de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias MĂ©dicas. Instituto de HistologĂa y EmbriologĂa de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Barrera, Patricia Andrea. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mendoza. Instituto de HistologĂa y EmbriologĂa de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias MĂ©dicas. Instituto de HistologĂa y EmbriologĂa de Mendoza Dr. Mario H. Burgos; ArgentinaFil: Tonn, Carlos Eugenio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - San Luis. Instituto de Investigaciones en TecnologĂa QuĂmica. Universidad Nacional de San Luis. Facultad de QuĂmica, BioquĂmica y Farmacia. Instituto de Investigaciones en TecnologĂa QuĂmica; ArgentinaFil: Sosa Escudero, Miguel Angel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mendoza. Instituto de HistologĂa y EmbriologĂa de Mendoza Dr. Mario H. Burgos. Universidad Nacional de Cuyo. Facultad de Ciencias MĂ©dicas. Instituto de HistologĂa y EmbriologĂa de Mendoza Dr. Mario H. Burgos; Argentin
The influence of maternal and infant nutrition on cardiometabolic traits: novel findings and future research directions from four Canadian birth cohort studies
A mother's nutritional choices while pregnant may have a great influence on her baby's development in the womb and during infancy. There is evidence that what a mother eats during pregnancy interacts with her genes to affect her child's susceptibility to poor health outcomes including childhood obesity, pre-diabetes, allergy and asthma. Furthermore, after what an infant eats can change his or her intestinal bacteria, which can further influence the development of these poor outcomes. In the present paper, we review the importance of birth cohorts, the formation and early findings from a multi-ethnic birth cohort alliance in Canada and summarise our future research directions for this birth cohort alliance. We summarise a method for harmonising collection and analysis of self-reported dietary data across multiple cohorts and provide examples of how this birth cohort alliance has contributed to our understanding of gestational diabetes risk; ethnic and diet-influences differences in the healthy infant microbiome; and the interplay between diet, ethnicity and birth weight. Ongoing work in this birth cohort alliance will focus on the use of metabolomic profiling to measure dietary intake, discovery of unique diet–gene and diet–epigenome interactions, and qualitative interviews with families of children at risk of metabolic syndrome. Our findings to-date and future areas of research will advance the evidence base that informs dietary guidelines in pregnancy, infancy and childhood, and will be relevant to diverse and high-risk populations of Canada and other high-income countries
IN VITRO ANTIOXIDANT CAPACITY, PHENOLIC, ASCORBIC ACID AND LYCOPENE CONTENT OF GUAVA (Psidium guajava L.) JUICES AND NECTARS
Coordenação de Aperfeiçoamento de Pessoal de NĂvel Superior (CAPES)Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq)The aim of this work was to determine the antioxidant capacity in vitro of three different brands of guava nectars and juices, through free radicals scavenging methods, 1,1-diphenyl-2-picrylhydrazine (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS(.+)), and its correlation with the total polyphenolic content, total lycopene and ascorbic acid. Brands revealed statistical differences (p <= 0.05) in antioxidant capacity, ranging from 1.9 to 7.7 molTE/mL. Antioxidant capacity presented positive correlation for ascorbic acid content and polyphenolic compounds, being relatively low for the lycopene. Different process can influence the content of these compounds as well as interfere in their antioxidant capacity. The control of the production process is important to add value to guava products and fulfill the new tendency of the market.272175182Coordenação de Aperfeiçoamento de Pessoal de NĂvel Superior (CAPES)Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de NĂvel Superior (CAPES)Conselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico (CNPq
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Investigating the impact of poverty on colonization and infection with drug-resistant organisms in humans: a systematic review
Background
Poverty increases the risk of contracting infectious diseases and therefore exposure to antibiotics. Yet there is lacking evidence on the relationship between income and non-income dimensions of poverty and antimicrobial resistance. Investigating such relationship would strengthen antimicrobial stewardship interventions.
Methods
A systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed, Ovid, MEDLINE, EMBASE, Scopus, CINAHL, PsychINFO, EBSCO, HMIC, and Web of Science databases were searched in October 2016. Prospective and retrospective studies reporting on income or non-income dimensions of poverty and their influence on colonisation or infection with antimicrobial-resistant organisms were retrieved. Study quality was assessed with the Integrated quality criteria for review of multiple study designs (ICROMS) tool.
Results
Nineteen articles were reviewed. Crowding and homelessness were associated with antimicrobial resistance in community and hospital patients. In high-income countries, low income was associated with Streptococcus pneumoniae and Acinetobacter baumannii resistance and a seven-fold higher infection rate. In low-income countries the findings on this relation were contradictory. Lack of education was linked to resistant S. pneumoniae and Escherichia coli. Two papers explored the relation between water and sanitation and antimicrobial resistance in low-income settings.
Conclusions
Despite methodological limitations, the results suggest that addressing social determinants of poverty worldwide remains a crucial yet neglected step towards preventing antimicrobial resistance
Predictive validity of the CriSTAL tool for short-term mortality in older people presenting at Emergency Departments: a prospective study
© 2018, The Author(s). Abstract: To determine the validity of the Australian clinical prediction tool Criteria for Screening and Triaging to Appropriate aLternative care (CRISTAL) based on objective clinical criteria to accurately identify risk of death within 3 months of admission among older patients. Methods: Prospective study of ≥ 65 year-olds presenting at emergency departments in five Australian (Aus) and four Danish (DK) hospitals. Logistic regression analysis was used to model factors for death prediction; Sensitivity, specificity, area under the ROC curve and calibration with bootstrapping techniques were used to describe predictive accuracy. Results: 2493 patients, with median age 78–80 years (DK–Aus). The deceased had significantly higher mean CriSTAL with Australian mean of 8.1 (95% CI 7.7–8.6 vs. 5.8 95% CI 5.6–5.9) and Danish mean 7.1 (95% CI 6.6–7.5 vs. 5.5 95% CI 5.4–5.6). The model with Fried Frailty score was optimal for the Australian cohort but prediction with the Clinical Frailty Scale (CFS) was also good (AUROC 0.825 and 0.81, respectively). Values for the Danish cohort were AUROC 0.764 with Fried and 0.794 using CFS. The most significant independent predictors of short-term death in both cohorts were advanced malignancy, frailty, male gender and advanced age. CriSTAL’s accuracy was only modest for in-hospital death prediction in either setting. Conclusions: The modified CriSTAL tool (with CFS instead of Fried’s frailty instrument) has good discriminant power to improve prognostic certainty of short-term mortality for ED physicians in both health systems. This shows promise in enhancing clinician’s confidence in initiating earlier end-of-life discussions
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