Separating ventricular activity in thoracic EIT using 4D image-based FEM simulations

One challenge in central hemodynamic monitoring based on electrical impedance tomography (EIT) is to robustly detect ventricular signal components and the corresponding EIT image region without external monitoring information. Current stimulation and voltage measurement of EIT were simulated with finite element porcine torso models in presence of a multitude ofthoracic blood volume shifts. The simulated measurement data was examined for linear dependence on changes in stroke volume. Based onthe results the EIT measurement information regardingstroke volume changesis sparse

The Effects of Foam Rolling on Flexibility

Studies have conflicting research based on whether foam rolling shows a significant difference in flexibility with the lower extremities. PURPOSE: To determine if there will be a significant difference in flexibility when using a foam roller compared to a five minute walk. METHODS: On the initial visit 14 participants self-reported their age, weight, and height, and then had their baseline flexibility assessed. Treatment conditions consisted of: 1) using a foam roller on the hamstrings, quadriceps, calves, and lower back, and 2) walking on a treadmill for five minutes. After each session, participant’s flexibility was measured three times with the Sit and Reach test. SPSS(V23) was used to conduct a repeated measures ANOVA to explore the difference in flexibility between the trials. The alpha was set at .05. RESULTS: A Repeated Measures ANOVA indicated a significant difference existed among the three levels of flexibility, F(2, 14) = 15.6, p = .001. Pairwise comparisons indicate a significant increase in flexibility after foam rolling compared to walking (+2.29 cm, p = .003) and baseline (+3.81 cm, p = .001). CONCLUSION: This study suggests that foam rolling is a better means to acutely increase flexibility compared to walking, therefore the predicted hypothesis that there will be a significant difference in lower body flexibility when using foam rolling compared to a five minute walk was accepted

Driver behaviour with adaptive cruise control

This paper reports on the evaluation of adaptive cruise control (ACC) from a psychological perspective. It was anticipated that ACC would have an effect upon the psychology of driving, i.e. make the driver feel like they have less control, reduce the level of trust in the vehicle, make drivers less situationally aware, but workload might be reduced and driving might be less stressful. Drivers were asked to drive in a driving simulator under manual and ACC conditions. Analysis of variance techniques were used to determine the effects of workload (i.e. amount of traffic) and feedback (i.e. degree of information from the ACC system) on the psychological variables measured (i.e. locus of control, trust, workload, stress, mental models and situation awareness). The results showed that: locus of control and trust were unaffected by ACC, whereas situation awareness, workload and stress were reduced by ACC. Ways of improving situation awareness could include cues to help the driver predict vehicle trajectory and identify conflicts

Ensembles of probability estimation trees for customer churn prediction

Customer churn prediction is one of the most, important elements tents of a company's Customer Relationship Management, (CRM) strategy In tins study, two strategies are investigated to increase the lift. performance of ensemble classification models, i.e (1) using probability estimation trees (PETs) instead of standard decision trees as base classifiers; and (n) implementing alternative fusion rules based on lift weights lot the combination of ensemble member's outputs Experiments ale conducted lot font popular ensemble strategics on five real-life chin n data sets In general, the results demonstrate how lift performance can be substantially improved by using alternative base classifiers and fusion tides However: the effect vanes lot the (Idol cut ensemble strategies lit particular, the results indicate an increase of lift performance of (1) Bagging by implementing C4 4 base classifiets. (n) the Random Subspace Method (RSM) by using lift-weighted fusion rules, and (in) AdaBoost, by implementing both

The impact of customer-specific marketing expenses on customer retention and customer profitability

We study the effects of customer-specific marketing expenses on customer retention and customer profitability in a business-to-business setting. Using data from a company providing hygiene services, we look at the impact of a hitherto unstudied type of expense targeted at individual customer relationships: the offering of free equipment to customers. The data allow tracking the activities performed in more than 4,500 customer relationships over a period of 4 years. Retention rates are higher for customers targeted with free equipment, but this effect results from an interaction with customer size. First-order dynamic panel data analyses show that the impact of targeted marketing expenses on customer dollar profit is positive for large customers, but there is no effect for smaller customers. Thus, targeted marketing expenses seem to be a tool for relationship maintenance rather than customer development: they help in retaining large customers that generate more profit, but they do not seem to work in developing new customers into larger, more profitable ones

Cirsium species show disparity in patterns of genetic variation at their range-edge, despite similar patterns of reproduction and isolation

Genetic variation was assessed across the UK geographical range of Cirsium acaule and Cirsium heterophyllum. A decline in genetic diversity and increase in population divergence approaching the range edge of these species was predicted based on parallel declines in population density and seed production reported seperately. Patterns were compared with UK populations of the widespread Cirsium arvense.Populations were sampled along a latitudinal transect in the UK and genetic variation assessed using microsatellite markers. Cirsium acaule shows strong isolation by distance, a significant decline in diversity and an increase in divergence among range-edge populations. Geographical structure is also evident in C. arvense, whereas no such patterns are seen in C.heterophyllum. There is a major disparity between patterns of genetic variation in C. acaule and C. heterophyllum despite very similar patterns in seed production and population isolation in these species. This suggests it may be misleading to make assumptions about the geographical structure of genetic variation within species based solely on the present-day reproduction and distribution of populations

Identification of evolutionary and kinetic drivers of NAD-dependent signaling

Nicotinamide adenine dinucleotide (NAD) provides an important link between metabolism and signal transduction and has emerged as central hub between bioenergetics and all major cellular events. NAD-dependent signaling (e.g., by sirtuins and poly-adenosine diphosphate [ADP] ribose polymerases [PARPs]) consumes considerable amounts of NAD. To maintain physiological functions, NAD consumption and biosynthesis need to be carefully balanced. Using extensive phylogenetic analyses, mathematical modeling of NAD metabolism, and experimental verification, we show that the diversification of NAD-dependent signaling in vertebrates depended on 3 critical evolutionary events: 1) the transition of NAD biosynthesis to exclusive usage of nicotinamide phosphoribosyltransferase (NamPT); 2) the occurrence of nicotinamide N-methyltransferase (NNMT), which diverts nicotinamide (Nam) from recycling into NAD, preventing Nam accumulation and inhibition of NAD-dependent signaling reactions; and 3) structural adaptation of NamPT, providing an unusually high affinity toward Nam, necessary to maintain NAD levels. Our results reveal an unexpected coevolution and kinetic interplay between NNMT and NamPT that enables extensive NAD signaling. This has implications for therapeutic strategies of NAD supplementation and the use of NNMT or NamPT inhibitors in disease treatment

Análise de timol em cera de abelha por micro-extracção em fase sólida (SPME)

A aplicação contínua de acaricídas lipofílicos sintéticos no tratamento das abelhas conduz a uma acumulação que depende da frequência, lipofilicidade e quantidade de princípio activo utilizada. Este efeito é mais acentuado na cera de abelha que no mel, no entanto, e porque a persistência destes resíduos é elevada, provoca o aparecimento de resistências e a perda do seu efeito acaricida.[1] Esta razão levou à pesquisa de outros compostos alternativos não tóxicos e não persistentes, com efeito sobre o ácaro das abelhas, Varroa Jacobsoni. Entre estes compostos encontra-se o timol, um composto fenólico, volátil, presente no tomilho. Dos diversos componentes dos óleos essenciais este é sem dúvida o que demonstrou maior efeito acaricida, utilizando-se no tratamento das abelhas directamente ou como componente de diversas formulações.[2] Em Portugal, foi introduzido muito recentemente sob a forma comercial de APIGUARD: um gel, à base de timol, que controla termicamente a libertação do princípio activo. O controlo dos resíduos de timol na cera de abelha e no mel é assim um desafio actual quer do ponto de vista sanitário quer de qualidade alimentar. A micro-extracção em fase sólida (SPME) é uma técnica de preparação de amostras que se baseia na sorção de analítos no revestimento de uma fibra de sílica fundida e posterior desorção térmica no injector de um cromatógrafo em fase gasosa (GC). Para além de combinar num único processo etapas de extracção, purificação e concentração dos analitos, a técnica de SPME apresenta uma série de vantagens relativamente às técnicas de extracção convencionais, como a extracção líquido-líquido e extracção em fase sólida, nomeadamente a sua relativa simplicidade e rapidez, reduzido custo e não utilização de solventes para a extracção de analitos, para além de permitir a extracção por imersão directa na amostra gasosa ou líquida e extracção por amostragem do espaço-de-cabeça da amostra líquida ou sólida.[3] Ao contrário das técnicas tradicionais, que permitem uma extracção quantitativa dos analitos, a técnica de SPME baseia-se num equilíbrio de partição do analito. Esta particularidade torna a técnica de SPME bastante sensível a parâmetros experimentais que possam afectar os coeficientes de partição dos analitos e, consequentemente, a sensibilidade e reprodutibilidade dos resultados.[4] O objectivo deste trabalho é o desenvolvimento de uma metodologia para a análise de timol em ceras contaminadas, utilizando como padrão interno a benzofenona. Em primeiro lugar, procedeu-se à optimização da técnica através da determinação da quantidade de cera, temperatura de análise e período de contacto da fibra com o espaço-de-cabeça da amostra mais adequados para o caso em estudo. Numa segunda fase, procedeu-se à análise de diversas lâminas de cera contaminadas propositadamente com timol e sujeitas a diferentes condições de armazenamento: em frio, ao ar e em estufa. Finalmente, procedeu-se à construção da curva de calibração e quantificação do timol presente nas diversas amostras de cera analisadas. Considerando-se os resultados, para os níveis de contaminação avaliados, as condições analíticas mais adequadas ocorrem com a utilização de 1 g de cera, mantendo-se a fibra em contacto com o espaço-de-cabeça durante 40 minutos a uma temperatura de 60 ºC. Nestas condições experimentais foi possível obter uma boa correlação linear (r2=0,990) no intervalo de concentrações [3,5-14 mg/g]. A quantidade de timol encontrada nas amostras é significativamente inferior à colocada durante o processo de fabrico das lâminas, pelo que o processo de conservação não é o mais adequado, sendo evidente uma menor quantidade de timol quando a lâmina de cera é colocada na estufa

Affinity-restricted memory B cells dominate recall responses to heterologous flaviviruses

Memory B cells (MBCs) can respond to heterologous antigens either by molding new specificities through secondary germinal centers (GCs) or selecting pre-existing clones without further affinity maturation. To distinguish these mechanisms in flavivirus infections and immunizations, we studied recall responses to envelope protein domain III (DIII). Conditional deletion of activation induced cytidine deaminase (AID) between heterologous challenges of West Nile, Japanese encephalitis, Zika, and Dengue viruses did not affect recall responses. DIII-specific MBCs were contained mostly within the plasma cell-biased CD80(+) subset and few GCs arose following heterologous boosters, demonstrating that recall responses are confined by pre-existing clonal diversity. Measurement of monoclonal antibody binding affinity to DIII proteins, timed AID deletion, single cell RNA-sequencing, and lineage tracing experiments point to selection of relatively low affinity MBCs as a mechanism to promote diversity. Engineering immunogens to avoid this MBC diversity may facilitate flavivirus type-specific vaccines with minimized potential for infection enhancement

Identifying the neutrino mass spectrum from a supernova neutrino burst

We study the role that the future detection of the neutrino burst from a galactic supernova can play in the reconstruction of the neutrino mass spectrum. We consider all possible 3$\nu$ mass and flavor spectra which describe the solar and atmospheric neutrino data. For each of these spectra we find the observable effects of the supernova neutrino conversions both in the matter of the star and the earth. We show that studies of the electron neutrino and anineutrino spectra as well as observations of the neutral current effects from supernova will allow us (i) to identify the solar neutrino solution, (ii) to determine the type of mass hierarchy (normal or inverted) and (iii) to probe the mixing $|U_{e3}|^2$ to values as low as $10^{-4} - 10^{-3}$.Comment: 53 pages, 13eps figures. Substantial changes made, new results, figures and tables adde