Non-Destructive Global and Localized 2D T1/T2 NMR Relaxometry to Resolve Microstructure in Apples Affected by Watercore

Apples can be considered as having a complex system formed by several structures at different organization levels: macroscale (>100 μm) and microscale (<100 μm). This work implements 2D T1/T2 global and localized relaxometry sequences on whole apples to be able to perform an intensive non-destructive and non-invasive microstructure study. The 2D T1/T2 cross-correlation spectroscopy allows the extraction of quantitative information about the water compartmentation in different subcellular organelles. A clear difference is found as sound apples show neat peaks for water in different subcellular compartments, such as vacuolar, cytoplasmatic and extracellular water, while in watercore-affected tissues such compartments appear merged. Localized relaxometry allows for the predefinition of slices in order to understand the microstructure of a particular region of the fruit, providing information that cannot be derived from global 2D T1/T2 relaxometry.

Determinación de la amplificación sísmica local en el Campus Sur UPM mediante la técnica de sismología de microtremores ReMi.

En el Campus Sur de la Universidad Politécnica de Madrid se ha llevado a cabo un proyecto para obtener una caracterización del subsuelo mediante ensayos ReMi, en colaboración con el departamento de Geofísica del Instituto Geográfico Nacional. La técnica ReMi (Refraction Microtremor) permite, mediante ensayos geofísicos realizados localmente sobre el terreno,obtener los parámetros físicos del mismo, que resultan de especial interés en el ámbito de la ingeniería civil. Esta técnica se caracteriza por englobarse dentro de la sísmica pasiva, muy empleada en prospección geofísica y basada en la obtención del modelo subyacente de distribución de velocidades de propagación de la onda S en función de la profundidad, con la ventaja de aprovechar el ruido sísmico ambiental como fuente de energía. Fue desarrollada en el Laboratorio Sismológico de Nevada (EEUU) por Louie (2001), con el objetivo de presentar una técnica innovadora en la obtención de las velocidades de propagación de manera experimental. Presenta ciertas ventajas, como la observación directa de la dispersión de ondas superficiales,que da un buen resultado de la velocidad de onda S, siendo un método no invasivo, de bajo coste y buena resolución, aplicable en entornos urbanos o sensibles en los que tanto otras técnicas sismológicas como otras variedades de prospección presentan dificultades. La velocidad de propagación de la onda S en los 30 primeros metros VS30, es ampliamente reconocida como un parámetro equivalente válido para caracterizar geotécnicamente el subsuelo y se halla matemáticamente relacionada con la velocidad de propagación de las ondas superficiales a observar mediante la técnica ReMi. Su observación permite el análisis espectral de los registros adquiridos, obteniéndose un modelo representado por la curva de dispersión de cada emplazamiento, de modo que mediante una inversión se obtiene el modelo de velocidad de propagación en función de la profundidad. A través de estos modelos, pueden obtenerse otros parámetros de interés sismológico. Estos resultados se representan sobre mapas isométricos para obtener una relación espacial de los mismos, particularmente conocido como zonación sísmica. De este análisis se extrae que la VS30 promedio del Campus no es baja en exceso, correspondiéndose a posteriori con los resultados de amplificación sísmica, período fundamental de resonancia del lugar y profundidad del sustrato rocoso. En última instancia se comprueba que los valores de amplificación sísmica máxima y el período al cual se produce posiblemente coincidan con los períodos fundamentales de resonancia de algunos edificios del Campus. ABSTRACT In South Campus at Polytechnic University of Madrid, a project has been carried out to obtain a proper subsoil description by applying ReMi tests, in collaboration with the Department of Geophysics of the National Geographic Institute. Through geophysical tests conducted locally, the ReMi (Refraction Microtremor) technique allows to establish the physical parameters of soil, which are of special interest in the field of civil engineering. This technique is part of passive seismic methods, often used in geophysical prospecting. It focuses in obtaining the underlying model of propagation velocity distribution of the shear wave according to depth and has the advantage of being able to use seismic ambient noise as a source of energy. It was developed in the Nevada Seismological Laboratory (USA) by Louie (2001) as an innovative technique for obtaining propagation velocities experimentally. It has several other advantages, including the direct observation of the dispersion of surface waves, which allows to reliably measure S wave velocity. This is a non-invasive, low cost and good resolution method, which can be applied in urban or sensitive environments where other prospection methods present difficulties. The propagation velocity of shear waves in the first 30 meters Vs30 is widely recognized as a valid equivalent parameter to geotechnically characterize the subsurface. It is mathematically related to surface wave's velocity of propagation, which are to observe using REMI technique. Spectral analysis of acquired data sets up a model represented by the dispersion curve at each site, so that, using an inversion process, propagation velocity model in relation to depth is obtained. Through this models, other seismologically interesting parameters can be obtained. These results are represented on isometric maps in order to obtain a spatial relationship between them, a process which is known as seismic zonation. This analysis infers that Vs30 at South Campus is not alarmingly low , corresponding with subsequent results of seismic amplification, fundamental period of resonance of soil and depth of bedrock. Ultimately, it's found that calculated values of soil's fundamental periods at which maximum seismic amplification occurs, may possibly match fundamental periods of some Campus buildings.

Some recent applications of non-linear models to the engineering practice

The Department of Structural Analysis of the University of Santander has been for a longtime involved in the solution of the country´s practical engineering problems. Some of these have required the use of non-conventional methods of analysis, in order to achieve adequate engineering answers. As an example of the increasing application of non-linear computer codes in the nowadays engineering practice, some cases will be briefly presented. In each case, only the main features of the problem involved and the solution used to solve it will be shown

Piezoelectric sensing and non-parametric statistical signal processing for health monitoring of hysteretic dampers used in seismic-resistant structures

The paper proposes a new application of non-parametric statistical processing of signals recorded from vibration tests for damage detection and evaluation on I-section steel segments. The steel segments investigated constitute the energy dissipating part of a new type of hysteretic damper that is used for passive control of buildings and civil engineering structures subjected to earthquake-type dynamic loadings. Two I-section steel segments with different levels of damage were instrumented with piezoceramic sensors and subjected to controlled white noise random vibrations. The signals recorded during the tests were processed using two non-parametric methods (the power spectral density method and the frequency response function method) that had never previously been applied to hysteretic dampers. The appropriateness of these methods for quantifying the level of damage on the I-shape steel segments is validated experimentally. Based on the results of the random vibrations, the paper proposes a new index that predicts the level of damage and the proximity of failure of the hysteretic damper

Aberrant platelet-derived growth factor alpha-receptor transcript as a diagnostic marker for early human germ cell tumors of the adult testis.

Testicular germ cell tumors are the most common form of cancer in young adult males. They result from a derangement of primordial germ cells, and they grow out from a noninvasive carcinoma-in-situ precursor. Since carcinoma in situ can readily be cured by low-dose irradiation, there is a great incentive for non- or minimally invasive methods for detection of carcinoma in situ. We have recently shown that human Tera-2 embryonal carcinoma cells, obtained from a nonseminomatous testicular germ cell tumor, show alternative splicing and alternative promoter use of the platelet-derived growth factor alpha-receptor gene, giving rise to a unique 1.5-kb transcript. In this study we have set up a reverse transcriptase-polymerase chain reaction strategy for characterization of the various transcripts for this receptor. Using this technique, we show that a panel of 18 seminomas and II nonseminomatous testicular germ cell tumors all express the 1.5-kb transcript. In addition, a panel of 27 samples of testis parenchyma with established carcinoma in situ were all found to be positive for the 1.5-kb transcript, while parenchyma lacking carcinoma in situ, placenta, and control semen were all negative. These data show that the 1.5-kb platelet-derived growth factor alpha-receptor transcript can be used as a highly selective marker for detection of early stages of human testicular germ cell tumors.

Herdabilidade da velocidade de onda de pulso e associação do controle glicêmico e perfil lipídico com a rigidez arterial em uma população brasileira: \"Projeto Corações de Baependi\"

INTRODUÇÃO:A rigidez arterial aumentada é um importante determinante do risco cardiovascular e um forte preditor de morbimortalidade. Além disso, estudos demonstram que o enrijecimento vascular pode estar associado a fatores genéticos e metabólicos. Portanto,os objetivos do presente estudo são determinar a herdabilidade da velocidade de onda de pulso (VOP) e avaliar a associação do perfil lipídico e do controle glicêmico com o fenótipo de rigidez arterial em uma população brasileira.MÉTODOS:Foram selecionados 1675 indivíduos (ambos os gêneros com idade entre 18 e 102 anos) distribuídos em 109 famílias residentes no município de Baependi-MG. A VOP carótida-femoral foi avaliada de forma não invasiva através de um dispositivo automático.As variáveis lipídicas e a glicemia de jejum foram determinadas pelo método enzimático colorimétrico. Os níveis de hemoglobina glicada (HbA1c) foram determinados pelo método de cromatografia líquida de alta eficiência. As estimativas da herdabilidade da VOP foram calculadas utilizando-se a metodologia de componentes de variância implementadas no software SOLAR. RESULTADOS: A herdabilidade estimada para a VOP foi de 26%, sendo ajustada para idade, gênero, HbA1c e pressão arterial média. Os níveis de HbA1c foram associados a rigidez arterial, onde a elevação de uma unidade percentual da HbA1c representou um incremento de 54% na chance de risco para rigidez arterial aumentada. As variáveis lipídicas (LDL-c, HDL-c, colesterol não- HDL-c, colesterol total e triglicérides) apresentaram fraca correlação com a VOP. Além disso, uma análise de regressão linear estratificada para idade (ponto de corte >= 45 anos) demonstrou uma relação inversa entre LDL-c e VOP em mulheres com idade >= 45 anos. CONCLUSÃO: Os resultados indicam que a VOP apresenta herdabilidade intermediária (26%); a HbA1c esta fortemente associada a rigidez arterial aumentada; o LDL-c é inversamente relacionado com a VOP em mulheres com idade >= 45 anos, possivelmente devido às alterações metabólicas associadas à falência ovariana

Avaliação da gordura hepática utilizando ressonância magnética

A esteatose hepática, que se caracteriza pelo acúmulo excessivo de gordura nas células do fígado, é um problema que vem preocupando a comunidade médico-científica, pois sua incidência vem aumentando a nível global, com expectativa de se tornar a doença crônica hepática de maior predominância em várias partes do mundo. Apesar de ser considerada uma doença benigna, a esteatose pode evoluir para doenças mais graves como cirrose, fibrose avançada, esteato hepatite (com ou sem fibrose) ou carcinoma. Entretanto, é potencialmente reversível, mesmo em quadros mais graves, o que reforça a urgência de se desenvolver métodos confiáveis para detecção e avaliação, inclusive ao longo de tratamento. Os métodos atuais para diagnóstico e quantificação da gordura hepática ainda são falhos: com a ultrassonografia não se é capaz de realizar quantificação; a tomografia computadorizada faz uso de radiação ionizante; a punção (biópsia), considerada o padrão ouro, é precisa, mas invasiva e pontual. A Ressonância Magnética (RM), tanto com espectroscopia (MRS) como com imagem (MRI), são alternativas completamente não invasivas, capazes de fornecer o diagnóstico e quantificação da gordura infiltrada no fígado. Entretanto, os trabalhos encontrados na literatura utilizam sequências de pulsos desenvolvidas especialmente para esse fim, com métodos de pós-processamento extremamente rebuscados, o que não é compatível com o estado atual dos equipamentos encontrados em ambientes clínicos nem mesmo ao nível de experiência e conhecimento das equipes técnicas que atuam em clínicas de radiodiagnóstico. Assim, o objetivo central do presente trabalho foi avaliar o potencial da RM como candidato a método de diagnóstico e de quantificação de gordura em ambientes clínicos, utilizando, para isso, sequências de pulsos convencionais, disponíveis em qualquer sistema comercial de RM, com protocolos de aquisição e processamento compatíveis com àqueles realizados em exames clínicos, tanto no que se refere à simplicidade como ao tempo total de aquisição. Foram avaliadas diferentes abordagens de MRS e MRI utilizando a biópsia hepática como padrão de referência. Foram avaliados pacientes portadores de diabetes tipo II, que apresentam alta prevalência de esteatose hepática não alcoólica, além de grande variabilidade nos percentuais de gordura. Foram realizadas medidas de correlação, acurácia, sensibilidade e especificidade de cada uma das abordagens utilizadas. Todos os métodos avaliados apresentaram alto grau de correlação positiva (> 87%) com os dados obtidos de maneira invasiva, o que revela que os valores obtidos utilizando RM estão de acordo com aquilo observado pela biópsia hepática. Muito embora os métodos de processamento utilizados não sejam tão complexos quanto seriam necessários caso uma quantificação absoluta fosse desejada, nossas análises mostraram alta acurácia, especificidade e sensibilidade da RM na avaliação da esteatose. Em conclusão, a RM se apresenta, de fato, como uma excelente candidata para avaliar, de forma não invasiva, a fração de gordura hepática, mesmo quando se considera as limitações impostas por um ambiente clínico convencional. Isso sugere que essas novas metodologias podem começar a migrar para ambientes clínicos sem depender das sequências complexas e dos processamentos exóticos que estão descritos na literatura mais atual.

Intra-population variation and geographic correlation in Canthon humectus hidalgoensis using FTIR-ATR spectroscopy

In some cases external morphology is not sufficient to discern between populations of a species, as occurs in the dung beetle Canthon humectus hidalgoensis Bates; and much less to determine phenotypic distances between them. FTIR-ATR spectroscopy show several advantages over other identification techniques (e.g. morphological, genetic, and cuticular hydrocarbons analysis) due to the non-invasive manner of the sample preparation, the relative speed of sample analysis and the low-cost of this technology. The infrared spectrum obtained is recognized to give a unique ‘fingerprint’ because vibrational spectra are specific and unique to the molecular nature of the sample. In our study, results showed that proteins, amino acids and aromatic ethers of insect exocuticle have promising discriminative power to discern between different populations of C. h. hidalgoensis. Furthermore, the correlation between geographic distances between populations and the chemical distances obtained by proteins + amino acids + aromatic ethers was statistically significant, showing that the spectral and spatial information available of the taxa together with appropriated chemometric methods may help to a better understanding of the identity, structure, dynamics and diversity of insect populations.

Sea-floor images from during POLARSTERN cruise ANT-XV/3 to the Weddell Sea, Antarctica

Transects of a Remotely Operated Vehicle (ROV) providing sea-bed videos and photographs were carried out during POLARSTERN expedition ANT-XV/3 focussing on the ecology of benthic assemblages on the Antarctic shelf in the South-Eastern Weddell Sea. The ROV-system sprint 103 was equiped with two video- and one still camera, lights, flash-lights, compass, and parallel lasers providing a scale in the images, a tether-management system (TMS), a winch, and the board units. All cameras used the same main lense and could be tilted. Videos were recorded in Betacam-format and (film-)slides were made by decision of the scientific pilot. The latter were mainly made under the aspect to improve the identification of organisms depicted in the videos because the still photographs have a much higher optical resolution than the videos. In the photographs species larger than 3 mm, in the videos larger than 1 cm are recognisable and countable. Under optimum conditions the transects were strait; the speed and direction of the ROV were determined by the drift of the ship in the coastal current, since both, the ship and the ROV were used as a drifting system; the option to operate the vehicle actively was only used to avoide obstacles and to reach at best a distance of only approximately 30 cm to the sea-floor. As a consequence the width of the photographs in the foreground is approximately 50 cm. Deviations from this strategy resulted mainly from difficult ice- and weather conditions but also from high current velocity and local up-welling close to the sea-bed. The sea-bed images provide insights into the general composition of key species, higher systematic groups and ecological guilds. Within interdisciplinary approaches distributions of assemblages can be attributed to environmental conditions such as bathymetry, sediment characteristics, water masses and current regimes. The images also contain valuable information on how benthic species are associated to each other. Along the transects, small- to intermediate-scaled disturbances, e.g. by grounding icebergs were analysed and further impact to the entire benthic system by local succession of recolonisation was studied. This information can be used for models predicting the impact of climate change to benthic life in the Southern Ocean. All these approaches contribute to a better understanding of the fiunctioning of the benthic system and related components of the entire Antarctic marine ecosystem. Despite their scientific value the imaging methods meet concerns about the protection of sensitive Antarctic benthic systems since they are non-invasive and they also provide valuable material for education and outreach purposes.

Evaluation of a Quality Improvement Intervention for Anesthetic Management of Acute Ischemic Stroke Patients Undergoing Endovascular Therapy

Thesis (Master's)--University of Washington, 2016-06

Functional Optical Coherence Tomography: In Vivo Applications in Dermatology and Neuroscience

Thesis (Ph.D.)--University of Washington, 2016-06

The High Frequency Component of Heart Rate Variability and Delta EEG Power during Sleep in Healthy Women and Women with Irritable Bowel Syndrome

Thesis (Ph.D.)--University of Washington, 2016-06

Screening of obstructive and central apnoea/hypopnoea in children using variability: A preliminary study

Aim: Polysomnography (PSG) is the current standard protocol for sleep disordered breathing (SDB) investigation in children. Presently, there are limited reliable screening tests for both central (CE) and obstructive (OE) respiratory events. This study compared three indices, derived from pulse oximetry and electrocardiogram ( ECG), with the PSG gold standard. These indices were heart rate (HR) variability, arterial blood oxygen de-saturation (SaO(2)) and pulse transit time (PTT). Methods: 15 children (12 male) from routine PSG studies were recruited (aged 3 - 14 years). The characteristics of the three indices were based on known criteria for respiratory events (RPE). Their estimation singly and in combination was evaluated with simultaneous scored PSG recordings. Results: 215 RPE and 215 tidal breathing events were analysed. For OE, the obtained sensitivity was HR (0.703), SaO(2) (0.047), PTT (0.750), considering all three indices (0) and either of the indices (0.828) while specificity was (0.891), (0.938), (0.922), (0.953) and (0.859) respectively. For CE, the sensitivity was HR (0.715), SaO(2) (0.278), PTT (0.662), considering all indices (0.040) and either of the indices (0.868) while specificity was (0.815), (0.954), (0.901), (0.960) and (0.762) accordingly. Conclusions: Preliminary findings herein suggest that the later combination of these non-invasive indices to be a promising screening method of SDB in children.

Prediction of functional capacity in chronic heart failure patients using myocardial tissue Doppler

Background. Exercise therapy improves functional capacity in CHF, but selection and individualization of training would be helped by a simple non-invasive marker of peak VO2. Peak VO2 in these pts is difficult to predict without direct measurement, and LV ejection fraction is a poor predictor. Myocardial tissue velocities are less load-dependent, and may be predictive of the exercise response in CHF pts. We sought to use tissue velocity as a predictor of peak VO2 in CHF pts. Methods. Resting 2D-echocardiography and tissue Doppler imaging were performed in 182 CHF pts (159 male, age 62±10 years) before and after metabolic exercise testing. The majority of these patients (129, 71%) had an ischemic cardiomyopathy, with resting EF of 35±13% and a peak VO2 of 13.5±4.7 ml/kg/min. Results. Neither resting EF (r=0.15) nor peak EF (r=0.18, both p=NS) were correlated with peak VO2. However, peak VO2 correlated with peak systolic velocity in septal (Vss, r=0.31) and lateral walls (Vsl, r=0.26, both p=0.01). In a general linear model (r2 = 0.25), peak VO2 was calculated from the following equation: 9.6 + 0.68*Vss - 0.09*age + 0.06*maximum HR. This model proved to be a superior predictor of peak VO2 (r=0.51, p=0.01) than the standard prediction equations of Wasserman (r= -0.12, p=0.01). Conclusions. Resting tissue Doppler, age and maximum heart rate may be used to predict functional capacity in CHF patients. This may be of use in selecting and following the response to therapy, including for exercise training.

Development of a non-intrusive system to monitor radial pulse wave velocity

Understanding arterial distensibility has shown to be important in the pathogenesis of cardiovascular abnormalities like hypertension. It is also known that arterial pulse wave velocity (PWV) is a measure of the elasticity or stiffness of peripheral arterial blood vessels. However, it generally requires complex instrumentations to have an accurate measurement and not suited for continual monitoring. In this paper, it describes a simple and non-intrusive method to detect the cardiovascular pulse from a human wrist above the radial artery and a fingertip. The main components of this proposed method are a piezoelectric transducer and a photo-plethysmography circuitry. 5 healthy adults (4 male) with age ranging from 25 to 38 years were recruited. The timing consistency of the detected pulsations is first evaluated and compared to that obtained from a commercial electrocardiogram. Furthermore, the derived PWV is then assessed by the predicted values attained from regression equations of two previous similar studies. The results show good correlations (p < 0.05) and similarities for the former and latter respectively. The simplicity and non-invasive nature of the proposed method can be attractive for even younger or badly disturbed patients. Moreover, it can be used for prolonged monitoring for the comfort of the patients.