1,691 research outputs found
Eigenlogic: a Quantum View for Multiple-Valued and Fuzzy Systems
We propose a matrix model for two- and many-valued logic using families of
observables in Hilbert space, the eigenvalues give the truth values of logical
propositions where the atomic input proposition cases are represented by the
respective eigenvectors. For binary logic using the truth values {0,1} logical
observables are pairwise commuting projectors. For the truth values {+1,-1} the
operator system is formally equivalent to that of a composite spin 1/2 system,
the logical observables being isometries belonging to the Pauli group. Also in
this approach fuzzy logic arises naturally when considering non-eigenvectors.
The fuzzy membership function is obtained by the quantum mean value of the
logical projector observable and turns out to be a probability measure in
agreement with recent quantum cognition models. The analogy of many-valued
logic with quantum angular momentum is then established. Logical observables
for three-value logic are formulated as functions of the Lz observable of the
orbital angular momentum l=1. The representative 3-valued 2-argument logical
observables for the Min and Max connectives are explicitly obtained.Comment: 11 pages, 2 table
A Rare Case of a Systemic Non-Langerhans Histiocytosis Presenting with Diabetes Insipidus and a Tentorial Mass
Introduction
The histiocytoses are a group of clinically diverse diseases distinguished from one another based on the specific immunophenotype of the lesional cells, implying derivation from the same precursor cell. Langerhans cell histiocytoses (LCH) diseases stem from abnormal dendritic cell lineages, while the non-Langerhans cell histiocytoses (non-LCH) are usually derived from an abnormal monocyte/macrophage cell line.1 Non-LCH with central nervous system (CNS) involvement is predictive of poor outcome. Histopathology is used to make a diagnosis of non-LCH. Immunohistochemistry and the clinical setting are used to differentiate between the various subtypes of non-LCH.1 The non-LCH can be divided into cutaneous non-LCH, cutaneous with a major systemic component, and systemic non-LCH.1 Erdheim-Chester disease (ECD) and Rosai-Dorfman disease (RDD) are systemic non-LCH diseases.
First described in 1930, ECD is characterized by xanthogranulomatous accumulations. The extent of infiltration is heterogeneous and can include skin, bones, lungs, kidneys, and the CNS. Approximately 500 cases have been reported so far.2 The majority of ECD patients harbor an activating mutation of the proto-oncogene BRAF, namely BRAF-V600E.3 Recent studies indicate CNS involvement as a predictor of highest mortality among ECD patients.4 First described in 1969, RDD is characterized by accumulation of histiocytes exhibiting emperipolesis in lymph nodes, in the head and neck or in extranodal sites. Extranodal sites include the CNS, skin, soft tissue and gastrointestinal tract. The clinical presentation is typically painless cervical lymphadenopathy with leukocytosis and a fever.5 The etiology of RDD is unknown.6 RDD with CNS involvement is rare and approximately 210 cases have been reported. CNS involvement typically lacks extracranial lymphadenopathy and resembles meningioma radiologically and clinically. 1 Select cases have demonstrated a combined presentation of ECD and RDD.2
In this report we describe a rare case presenting with headache and with clinically and pathologically overlapping features of RDD and ECD. We describe treatment and complications and review the existing literature regarding diagnosis and treatment for these rare conditions
Growth characteristics in individuals with osteogenesis imperfecta in North America: results from a multicenter study.
PurposeOsteogenesis imperfecta (OI) predisposes people to recurrent fractures, bone deformities, and short stature. There is a lack of large-scale systematic studies that have investigated growth parameters in OI.MethodsUsing data from the Linked Clinical Research Centers, we compared height, growth velocity, weight, and body mass index (BMI) in 552 individuals with OI. Height, weight, and BMI were plotted on Centers for Disease Control and Prevention normative curves.ResultsIn children, the median z-scores for height in OI types I, III, and IV were -0.66, -6.91, and -2.79, respectively. Growth velocity was diminished in OI types III and IV. The median z-score for weight in children with OI type III was -4.55. The median z-scores for BMI in children with OI types I, III, and IV were 0.10, 0.91, and 0.67, respectively. Generalized linear model analyses demonstrated that the height z-score was positively correlated with the severity of the OI subtype (P < 0.001), age, bisphosphonate use, and rodding (P < 0.05).ConclusionFrom the largest cohort of individuals with OI, we provide median values for height, weight, and BMI z-scores that can aid the evaluation of overall growth in the clinic setting. This study is an important first step in the generation of OI-specific growth curves
Associations between fruit and vegetable intake, leisure-time physical activity, sitting time and self-rated health among older adults : cross-sectional data from the WELL study
BackgroundLifestyle behaviours, such as healthy diet, physical activity and sedentary behaviour, are key elements of healthy ageing and important modifiable risk factors in the prevention of chronic diseases. Little is known about the relationship between these behaviours in older adults. The purpose of this study was to explore the relationship between fruit and vegetable (F&V) intake, leisure-time physical activity (LTPA) and sitting time (ST), and their association with self-rated health in older adults.MethodsThis cross-sectional study comprised 3,644 older adults (48% men) aged 55-65 years, who participated in the Wellbeing, Eating and Exercise for a Long Life ("WELL") study. Respondents completed a postal survey about their health and their eating and physical activity behaviours in 2010 (38% response rate). Spearman\u27s coefficient (rho) was used to evaluate the relationship between F&V intake, LTPA and ST. Their individual and shared associations with self-rated health were examined using ordinal logistic regression models, stratified by sex and adjusted for confounders (BMI, smoking, long-term illness and socio-demographic characteristics).ResultsThe correlations between F&V intake, LTPA and ST were low. F&V intake and LTPA were positively associated with self-rated health. Each additional serving of F&V or MET-hour of LTPA were associated with approximately 10% higher likelihood of reporting health as good or better among women and men. The association between ST and self-rated health was not significant in the multivariate analysis. A significant interaction was found (ST*F&V intake). The effect of F&V intake on self-rated health increased with increasing ST in women, whereas the effect decreased with increasing ST in men.ConclusionThis study contributes to the scarce literature related to lifestyle behaviours and their association with health indicators among older adults. The findings suggest that a modest increase in F&V intake, or LTPA could have a marked effect on the health of older adults. Further research is needed to fully understand the correlates and determinants of lifestyle behaviours, particularly sitting time, in this age group
Candidiasis : predisposing factors, prevention, diagnosis and alternative treatment
Candidiasis is the most common opportunistic yeast infection. Candida species and other microorganisms are involved in this complicated fungal infection, but Candida albicans continues to be the most prevalent. In the past two decades, it has been observed an abnormal overgrowth in the gastrointestinal, urinary and respiratory tracts, not only in immunocompromised patients, but also related to nosocomial infections and even in healthy individuals. There is a widely variety of causal factors that contribute to yeast infection which means that candidiasis is a good example of a multifactorial syndrome. Due to rapid increase in the incidence in these infections, this is the subject of numerous studies. Recently, the focus of attention is the treatment and, above all, the prevention of those complications. The diagnosis of candidiasis could become quite complicated. Prevention is the most effective “treatment,” much more than eradication of the yeast with antifungal agents. There are several aspects to consider in the daily routine that can provide a strength protection. However, a therapeutic approach is necessary when the infection is established, and therefore, other alternatives should be explored. This review provides an overview on predisposition factors, prevention and diagnosis of candidiasis, highlighting alternative approaches for candidiasis treatment.The authors are grateful to Foundation for Science and Technology (FCT, Portugal) for N. Martins grant (SFRH/BD/87658/2012), L. Barros researcher contract under "Programa Compromisso com Ciencia-2008'' and financial support to the research center CIMO (strategic project PEst-OE/AGR/UI0690/2011)
Effective Rheology of Bubbles Moving in a Capillary Tube
We calculate the average volumetric flux versus pressure drop of bubbles
moving in a single capillary tube with varying diameter, finding a square-root
relation from mapping the flow equations onto that of a driven overdamped
pendulum. The calculation is based on a derivation of the equation of motion of
a bubble train from considering the capillary forces and the entropy production
associated with the viscous flow. We also calculate the configurational
probability of the positions of the bubbles.Comment: 4 pages, 1 figur
Insufficient weight at birth and preschool-age growth in children attending charitably funded crèches in the municipality of Santo André , in the State of São Paulo , Brazil
OBJETIVOS: comparar o crescimento alcançado e a prevalência de baixa estatura na idade pré-escolar entre recém-nascidos de peso insuficiente (PNI) e de peso adequado (PNA). MÉTODOS: foram estudadas 323 crianças com PNI e 886 com PNA de famílias de baixa renda de quinze creches filantrópicas de Santo André, São Paulo, Brasil, em 2001 e 2002. As variáveis foram o escore Z de peso e de estatura para a idade, pelo referencial Center for Disease Control (CDC) and National Center for Health Statistics (NCHS) 2000, comparando-se as médias dos dois grupos. Calculou-se a razão de prevalência (RP) de baixa estatura na idade pré-escolar em decorrência do peso insuficiente ao nascer. RESULTADOS: o escore z médio de peso foi -0,09 e 0,39 e o escore z médio de estatura foi de -0,06 e de 0,24 para as crianças de PNI e de PNA, respectivamente. A prevalência de baixa estatura foi de 2,78% para as crianças com PNI e de 0,79% para aquelas com PNA. A RP de baixa estatura na idade pré-escolar para as crianças de PNI foi de 3,5 (IC95% 1,3-9,4). CONCLUSÕES: as crianças com PNI apresentaram crescimento inferior e maior risco de falhas de crescimento até a idade pré-escolar, sugerindo um efeito negativo do peso insuficiente ao nascer sobre o crescimento infantil.OBJECTIVES: to compare rate of growth and prevalence of low stature at preschool age in children who were underweight at birth and in children born with a normal weight. METHODS: the study covered 323 children born underweight and 886 born with a normal weight from low-income families in fifteen charitably funded crèches in the municipality of Santo André, in the State of São Paulo, Brazil, in 2001 and 2002. The variables used were the z score for weight and height for age, using the Center for Disease Control (CDC) and National Center for Health Statistics (NCHS) 2000 benchmark, comparing the means for the two groups. The prevalence ratio was calculated for low stature in preschool age children resulting from insufficient weight at birth. RESULTS: the z score for weight was -0.09 and 0.39 and the average z score for height was -0.06 and 0.24 for underweight and normal weight at birth, respectively. The prevalence of low stature was 2.78% for children born underweight and 0.79% for normal weight. The PR for low stature at preschool age for children born underweight was 3.5 (CI95% 1.3-9.4). CONCLUSIONS: children born underweight had a lower rate of growth and greater risk of developing a growth disorder up to preschool age, suggesting a negative effect of insufficient birth weight on child growth
Occupational Exposure to Endocrine-Disrupting Chemicals and Birth Weight and Length of Gestation: A European Meta-Analysis
BACKGROUND: Women of reproductive age can be exposed to
endocrine-disrupting chemicals (EDCs) at work and exposure to
EDCs in pregnancy may affect fetal growth. OBJECTIVES: We
assessed whether maternal occupational exposure to EDCs during
pregnancy as classified by application of a job exposure matrix
was associated with birth weight, term low birth weight (LBW),
length of gestation, and preterm delivery. METHODS: Using
individual participant data from 133,957 mother-child pairs in
13 European cohorts spanning births from 1994 to 2011, we linked
maternal job titles with exposure to 10 EDC groups as assessed
through a job exposure matrix. For each group, we combined the
two levels of exposure categories (possible and probable) and
compared birth outcomes with the unexposed group (exposure
unlikely). We performed meta-analyses of cohort-specific
estimates. RESULTS: Eleven percent of pregnant women were
classified as exposed to EDCs at work during pregnancy based on
job title. Classification of exposure to one or more EDC group
was associated with an increased risk of term LBW (OR 1.25,
95%CI 1.04, 1.49), as were most specific EDC groups; this
association was consistent across cohorts. Further, the risk
increased with increasing number of EDC groups (OR 2.11 95%CI
1.10, 4.06 for exposure to 4 or more EDC groups). There were few
associations (p < 0.05) with the other outcomes; women
holding job titles classified as exposed to bisphenol A or
brominated flame retardants were at higher risk for longer
length of gestation. CONCLUSION: Results from our large
population-based birth cohort design indicate that employment
during pregnancy in occupations classified as possibly or
probably exposed to EDCs was associated with an increased risk
of term LBW
Prostate cancer disparities in Black men of African descent: a comparative literature review of prostate cancer burden among Black men in the United States, Caribbean, United Kingdom, and West Africa
<p>Abstract</p> <p>Background</p> <p>African American men have the highest prostate cancer morbidity and mortality rates than any other racial or ethnic group in the US. Although the overall incidence of and mortality from prostate cancer has been declining in White men since 1991, the decline in African American men lags behind White men. Of particular concern is the growing literature on the disproportionate burden of prostate cancer among other Black men of West African ancestry in the Caribbean Islands, United Kingdom and West Africa. This higher incidence of prostate cancer observed in populations of African descent may be attributed to the fact that these populations share ancestral genetic factors. To better understand the burden of prostate cancer among men of West African Ancestry, we conducted a review of the literature on prostate cancer incidence, prevalence, and mortality in the countries connected by the Transatlantic Slave Trade.</p> <p>Results</p> <p>Several published studies indicate high prostate cancer burden in Nigeria and Ghana. There was no published literature for the countries Benin, Gambia and Senegal that met our review criteria. Prostate cancer morbidity and/or mortality data from the Caribbean Islands and the United Kingdom also provided comparable or worse prostate cancer burden to that of US Blacks.</p> <p>Conclusion</p> <p>The growing literature on the disproportionate burden of prostate cancer among other Black men of West African ancestry follows the path of the Transatlantic Slave Trade. To better understand and address the global prostate cancer disparities seen in Black men of West African ancestry, future studies should explore the genetic and environmental risk factors for prostate cancer among this group.</p
Effect of ionic strength and presence of serum on lipoplexes structure monitorized by FRET
<p>Abstract</p> <p>Background</p> <p>Serum and high ionic strength solutions constitute important barriers to cationic lipid-mediated intravenous gene transfer. Preparation or incubation of lipoplexes in these media results in alteration of their biophysical properties, generally leading to a decrease in transfection efficiency. Accurate quantification of these changes is of paramount importance for the success of lipoplex-mediated gene transfer <it>in vivo</it>.</p> <p>Results</p> <p>In this work, a novel time-resolved fluorescence resonance energy transfer (FRET) methodology was used to monitor lipoplex structural changes in the presence of phosphate-buffered saline solution (PBS) and fetal bovine serum. 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP)/pDNA lipoplexes, prepared in high and low ionic strength solutions, are compared in terms of complexation efficiency. Lipoplexes prepared in PBS show lower complexation efficiencies when compared to lipoplexes prepared in low ionic strength buffer followed by addition of PBS. Moreover, when serum is added to the referred formulation no significant effect on the complexation efficiency was observed. In physiological saline solutions and serum, a multilamellar arrangement of the lipoplexes is maintained, with reduced spacing distances between the FRET probes, relative to those in low ionic strength medium.</p> <p>Conclusion</p> <p>The time-resolved FRET methodology described in this work allowed us to monitor stability and characterize quantitatively the structural changes (variations in interchromophore spacing distances and complexation efficiencies) undergone by DOTAP/DNA complexes in high ionic strength solutions and in presence of serum, as well as to determine the minimum amount of potentially cytotoxic cationic lipid necessary for complete coverage of DNA. This constitutes essential information regarding thoughtful design of future <it>in vivo </it>applications.</p
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