Decay of correlations for maps with uniformly contracting fibers and logarithm law for singular hyperbolic attractors

We consider two dimensional maps preserving a foliation which is uniformly contracting and a one dimensional associated quotient map having exponential convergence to equilibrium (iterates of Lebesgue measure converge exponentially fast to physical measure). We prove that these maps have exponential decay of correlations over a large class of observables. We use this result to deduce exponential decay of correlations for the Poincare maps of a large class of singular hyperbolic flows. From this we deduce logarithm laws for these flows.Comment: 39 pages; 03 figures; proof of Theorem 1 corrected; many typos corrected; improvements on the statements and comments suggested by a referee. Keywords: singular flows, singular-hyperbolic attractor, exponential decay of correlations, exact dimensionality, logarithm la

PEEP-ZEEP technique: cardiorespiratory repercussions in mechanically ventilated patients submitted to a coronary artery bypass graft surgery

<p>Abstract</p> <p>Background</p> <p>The PEEP-ZEEP technique is previously described as a lung inflation through a positive pressure enhancement at the end of expiration (PEEP), followed by rapid lung deflation with an abrupt reduction in the PEEP to 0 cmH₂O (ZEEP), associated to a manual bilateral thoracic compression.</p> <p>Aim</p> <p>To analyze PEEP-ZEEP technique's repercussions on the cardio-respiratory system in immediate postoperative artery graft bypass patients.</p> <p>Methods</p> <p>15 patients submitted to a coronary artery bypass graft surgery (CABG) were enrolled prospectively, before, 10 minutes and 30 minutes after the technique. Patients were curarized, intubated, and mechanically ventilated. To perform PEEP-ZEEP technique, saline solution was instilled into their orotracheal tube than the patient was reconnected to the ventilator. Afterwards, the PEEP was increased to 15 cmH₂O throughout 5 ventilatory cycles and than the PEEP was rapidly reduced to 0 cmH₂O along with manual bilateral thoracic compression. At the end of the procedure, tracheal suction was accomplished.</p> <p>Results</p> <p>The inspiratory peak and plateau pressures increased during the procedure (p < 0.001) compared with other pressures during the assessment periods; however, they were within lung safe limits. The expiratory flow before the procedure were 33 ± 7.87 L/min, increasing significantly during the procedure to 60 ± 6.54 L/min (p < 0.001), diminishing to 35 ± 8.17 L/min at 10 minutes and to 36 ± 8.48 L/min at 30 minutes. Hemodynamic and oxygenation variables were not altered.</p> <p>Conclusion</p> <p>The PEEP-ZEEP technique seems to be safe, without alterations on hemodynamic variables, produces elevated expiratory flow and seems to be an alternative technique for the removal of bronchial secretions in patients submitted to a CABG.</p

Can Score Databanks Help Teaching?

Basic courses in most medical schools assess students' performance by conferring scores. The objective of this work is to use a large score databank for the early identification of students with low performance and to identify course trends based on the mean of students' grades. METHODOLOGY/PRINCIPAL FINDINGS: We studied scores from 2,398 medical students registered in courses over a period of 10 years. Students in the first semester were grouped into those whose ratings remained in the lower quartile in two or more courses (low-performance) and students who had up to one course in the lower quartile (high-performance). ROC curves were built, aimed at the identification of a cut-off average score in the first semesters that would be able to predict low performances in future semesters. Moreover, to follow the long-term pattern of each course, the mean of all scores conferred in a semester was compared to the overall course mean obtained by averaging 10 years of data. Individuals in the low-performance group had a higher risk of being in the lower quartile of at least one course in the second semester (relative risk 3.907; 95% CI: 3.378-4.519) and in the eighth semester (relative risk 2.873; 95% CI: 2.495-3.308). The prediction analysis revealed that an average score of 7.188 in the first semester could identify students that presented scores below the lower quartiles in both the second and eighth semesters (p<0.0001 for both AUC). When scores conferred by single courses were compared over time, three time-trend patterns emerged: low variation, upward trend and erratic pattern. CONCLUSION/SIGNIFICANCE: An early identification of students with low performance may be useful in promoting pedagogical strategies for these individuals. Evaluation of the time trend of scores conferred by courses may help departments monitoring changes in personnel and methodology that may affect a student's performance

Fatores de risco para quedas em pacientes adultos hospitalizados: um estudo caso-controle

Objective: to identify risk factors for falls in hospitalized adult patients. Methods: a matched case-control study (one control for each case). A quantitative study conducted in clinical and surgical units of a teaching hospital in Southern Brazil. The sample comprised 358 patients. Data were collected over 18 months between 2013-2014. Data analysis was performed with descriptive statistics and conditional logistic regression using Microsoft Excel and SPSS version 18.0. Results: risk factors identified were: disorientation/confusion [OR 4.25 (1.99 to 9.08), p&lt;0.001]; frequent urination [OR 4.50 (1.86 to 10.87), p=0.001]; walking limitation [OR 4.34 (2.05 to 9.14), p&lt;0.001]; absence of caregiver [OR 0.37 (0.22 to 0.63), p&lt;0.001]; postoperative period [OR 0.50 (0.26 to 0.94), p=0.03]; and number of medications administered within 72 hours prior the fall [OR 1.20 (1.04 to 1.39) p=0.01]. Conclusion: risk for falls is multifactorial. However, understanding these factors provides support to clinical decision-making and positively influences patient safety.Objetivo: identificar los factores de riesgo para la ocurrencia de caídas en pacientes adultos hospitalizados. Métodos: un estudio caso-control emparejado (un control para cada caso). Investigación cuantitativa llevada a cabo en unidades clínicas y quirúrgicas de un hospital universitario en el Sur de Brasil. La muestra constó de 358 pacientes. Se recopilaron datos durante 18 meses, entre 2013-2014. El análisis de los datos se realizó mediante estadística descriptiva y regresión logística condicional, utilizando el Microsoft Excel y el SPSS versión 18.0. Resultados: los factores de riesgo identificados fueron: desorientación/confusión [OR 4,25 (1,99 a 9,08), p&lt;0,001]; micción frecuente [OR 4,50 (1,86 a 10,87), p=0,001]; limitación para caminar [OR 4,34 (2,05 a 9,14), p&lt;0,001]; ausencia de cuidadores [OR 0,37 (0,22 a 0,63), p&lt;0,001]; período postoperatorio [OR 0,50 (0,26 a 0,94), p=0,03]; y número de medicamentos administrados dentro de las 72 horas previas a la caída [OR 1,20 (1,04 a 1,39) p=0,01]. Conclusión: los riesgos de caídas son multifactoriales. Sin embargo, la comprensión de estos factores respalda la toma de decisiones clínicas y tiene un impacto positivo en la seguridad del paciente.Objetivo: identificar os fatores de risco para a ocorrência de quedas em pacientes adultos hospitalizados. Métodos: estudo do tipo caso-controle pareado (um controle para cada caso). Pesquisa quantitativa realizada em unidades clínicas e cirúrgicas de um hospital universitário da região Sul do Brasil. A amostra incluiu 358 pacientes. Os dados foram coletados durante 18 meses, entre 2013-2014. A análise dos dados foi realizada por meio de estatística descritiva e regressão logística condicional, utilizando o Microsoft Excel e o SPSS versão 18.0. Resultados: os fatores de risco identificados foram: desorientação/confusão [OR 4,25 (1,99 a 9,08), p&lt;0,001]; micção frequente [OR 4,50 (1,86 a 10,87), p=0,001]; limitação para caminhar [OR 4,34 (2,05 a 9,14), p&lt;0,001]; ausência de cuidador [OR 0,37 (0,22 a 0,63), p&lt;0,001]; período pós-operatório [OR 0,50 (0,26 a 0,94), p=0,03]; e o número de medicamentos administrados nas 72 horas anteriores à queda [OR 1,20 (1,04 a 1,39) p=0,01]. Conclusão: os riscos para quedas são multifatoriais. Todavia, conhecê-los dá suporte à decisão clínica do enfermeiro, o que contribui para a busca das melhores intervenções preventivas e impacta positivamente na segurança dos pacientes

Evaluation of 3-(3-chloro-phenyl)-5-(4-pyridyl)-4,5-dihydroisoxazole as a Novel Anti-Inflammatory Drug Candidate

BACKGROUND: 3-(3-chloro-phenyl)-5-(4-pyridyl)-4,5-dihydroisoxazole (DIC) is a five-membered heterocyclic compound containing a N-O bond. The anti-inflammatory effects of this compound were studied both in vitro and in vivo. PRINCIPAL FINDINGS: DIC effectively decreased TNF-α and IL-6 release from LPS-stimulated macrophages in a dose dependent manner. DIC diminished the levels of COX-2 with subsequent inhibition of PGE(2) production. DIC also compromised HMGB1 translocation from the nucleus to the cytoplasm. Moreover, DIC prevented the nuclear translocation of NF-κB and inhibited the MAPK pathway. In vivo, DIC inhibited migration of neutrophils to the peritoneal cavity of mice. CONCLUSIONS: This study presents the potential utilization of a synthetic compound, as a lead for the development of novel anti-inflammatory drugs

DNA Barcoding Bromeliaceae: Achievements and Pitfalls

<div><h3>Background</h3><p>DNA barcoding has been successfully established in animals as a tool for organismal identification and taxonomic clarification. Slower nucleotide substitution rates in plant genomes have made the selection of a DNA barcode for land plants a much more difficult task. The Plant Working Group of the Consortium for the Barcode of Life (CBOL) recommended the two-marker combination <em>rbcL</em>/<em>matK</em> as a pragmatic solution to a complex trade-off between universality, sequence quality, discrimination, and cost.</p> <h3>Methodology/Principal Findings</h3><p>It is expected that a system based on any one, or a small number of plastid genes will fail within certain taxonomic groups with low amounts of plastid variation, while performing well in others. We tested the effectiveness of the proposed CBOL Plant Working Group barcoding <em>markers</em> for land plants in identifying 46 bromeliad species, a group rich in endemic species from the endangered Brazilian Atlantic Rainforest. Although we obtained high quality sequences with the suggested primers, species discrimination in our data set was only 43.48%. Addition of a third marker, <em>trnH–psbA</em>, did not show significant improvement. This species identification failure in Bromeliaceaecould also be seen in the analysis of the GenBank's <em>matK</em> data set. Bromeliaceae's sequence divergence was almost three times lower than the observed for Asteraceae and Orchidaceae. This low variation rate also resulted in poorly resolved tree topologies. Among the three Bromeliaceae subfamilies sampled, Tillandsioideae was the only one recovered as a monophyletic group with high bootstrap value (98.6%). Species paraphyly was a common feature in our sampling.</p> <h3>Conclusions/Significance</h3><p>Our results show that although DNA barcoding is an important tool for biodiversity assessment, it tends to fail in taxonomy complicated and recently diverged plant groups, such as Bromeliaceae. Additional research might be needed to develop markers capable to discriminate species in these complex botanical groups.</p> </div

Evaluation of movements of lower limbs in non-professional ballet dancers: hip abduction and flexion

<p>Abstract</p> <p>Background</p> <p>The literature indicated that the majority of professional ballet dancers present static and active dynamic range of motion difference between left and right lower limbs, however, no previous study focused this difference in non-professional ballet dancers. In this study we aimed to evaluate active movements of the hip in non-professional classical dancers.</p> <p>Methods</p> <p>We evaluated 10 non professional ballet dancers (16-23 years old). We measured the active range of motion and flexibility through Well Banks. We compared active range of motion between left and right sides (hip flexion and abduction) and performed correlation between active movements and flexibility.</p> <p>Results</p> <p>There was a small difference between the right and left sides of the hip in relation to the movements of flexion and abduction, which suggest the dominant side of the subjects, however, there was no statistical significance. Bank of Wells test revealed statistical difference only between the 1^stand the 3^rdmeasurement. There was no correlation between the movements of the hip (abduction and flexion, right and left sides) with the three test measurements of the bank of Wells.</p> <p>Conclusion</p> <p>There is no imbalance between the sides of the hip with respect to active abduction and flexion movements in non-professional ballet dancers.</p

Pneumolysin Activates the NLRP3 Inflammasome and Promotes Proinflammatory Cytokines Independently of TLR4

Pneumolysin (PLY) is a key Streptococcus pneumoniae virulence factor and potential candidate for inclusion in pneumococcal subunit vaccines. Dendritic cells (DC) play a key role in the initiation and instruction of adaptive immunity, but the effects of PLY on DC have not been widely investigated. Endotoxin-free PLY enhanced costimulatory molecule expression on DC but did not induce cytokine secretion. These effects have functional significance as adoptive transfer of DC exposed to PLY and antigen resulted in stronger antigen-specific T cell proliferation than transfer of DC exposed to antigen alone. PLY synergized with TLR agonists to enhance secretion of the proinflammatory cytokines IL-12, IL-23, IL-6, IL-1β, IL-1α and TNF-α by DC and enhanced cytokines including IL-17A and IFN-γ by splenocytes. PLY-induced DC maturation and cytokine secretion by DC and splenocytes was TLR4-independent. Both IL-17A and IFN-γ are required for protective immunity to pneumococcal infection and intranasal infection of mice with PLY-deficient pneumococci induced significantly less IFN-γ and IL-17A in the lungs compared to infection with wild-type bacteria. IL-1β plays a key role in promoting IL-17A and was previously shown to mediate protection against pneumococcal infection. The enhancement of IL-1β secretion by whole live S. pneumoniae and by PLY in DC required NLRP3, identifying PLY as a novel NLRP3 inflammasome activator. Furthermore, NLRP3 was required for protective immunity against respiratory infection with S. pneumoniae. These results add significantly to our understanding of the interactions between PLY and the immune system