Estimativa dos valores de MSAD em procedimentos de tomografia computadorizada utilizando filmes radiocrômicos

OBJETIVO: Verificar a viabilidade de filmes radiocrômicos como um dosímetro alternativo para estimativa da dose média em cortes múltiplos a partir dos perfis de kerma. MATERIAIS E MÉTODOS: Os filmes foram distribuídos em cilindros posicionados no centro e nas regiões periféricas de um objeto simulador padrão de abdome utilizado para dosimetria em tomografia computadorizada. RESULTADOS: Os valores de dose média em cortes múltiplos calculados foram 13,6 ± 0,7, 13,5 ± 0,7 e 18,7 ± 1,0 mGy para os valores de passo (pitch) de 0,75, 1,00 e 1,50, respectivamente. CONCLUSÃO: Apesar de os resultados mostrarem valores menores que o nível de referência de radiodiagnóstico de 25 mGy estabelecido pela legislação brasileira para exames de abdome, eles sugerem que há espaço para otimização dos procedimentos e uma revisão do valor para o nível de referência de radiodiagnóstico brasileiro.

Strategies to evaluate the impact of rectal volume on prostate motion during three-dimensional conformal radiotherapy for prostate cancer

Abstract Objective: To evaluate the rectal volume influence on prostate motion during three-dimensional conformal radiotherapy (3D-CRT) for prostate cancer. Materials and Methods: Fifty-one patients with prostate cancer underwent a series of three computed tomography scans including an initial planning scan and two subsequent scans during 3D-CRT. The organs of interest were outlined. The prostate contour was compared with the initial CT images considering the anterior, posterior, superior, inferior and lateral edges of the organ. Variations in the anterior limits and volume of the rectum were assessed and correlated with prostate motion in the anteroposterior direction. Results: The maximum range of prostate motion was observed in the superoinferior direction, followed by the anteroposterior direction. A significant correlation was observed between prostate motion and rectal volume variation ( p = 0.037). A baseline rectal volume superior to 70 cm3 had a significant influence on the prostate motion in the anteroposterior direction ( p = 0.045). Conclusion: The present study showed a significant interfraction motion of the prostate during 3D-CRT with greatest variations in the superoinferior and anteroposterior directions, and that a large rectal volume influences the prostate motion with a cutoff value of 70 cm3. Therefore, the treatment of patients with a rectal volume > 70 cm3 should be re-planned with appropriate rectal preparation.

A new approach to segmentation based on fusing circumscribed contours, region growing and clustering

One of the major problems in machine vision is the segmentation of images of natural scenes. This paper presents a new proposal for the image segmentation problem which has been based on the integration of edge and region information. The main contours of the scene are detected and used to guide the posterior region growing process. The algorithm places a number of seeds at both sides of a contour allowing stating a set of concurrent growing processes. A previous analysis of the seeds permits to adjust the homogeneity criterion to the regions's characteristics. A new homogeneity criterion based on clustering analysis and convex hull construction is proposed

Concerto for Violin and Orchestra No. 1 in A minor : Add-a-soloist ; you play the solo part

r1955.

Concerto for Violin and Orchestra No. 2 in E major : Add-a-soloist ; you play the solo part

r1955.

The attenuation of concentrations model: a new method for assessing mercury mobility in sediments

In this work we propose a new approach for the determination of the mobility of mercury in sediments based on spatial distribution of concentrations. We chose the Tainheiros Cove, located in the Todos os Santos Bay, Brazil, as the study area, for it has a history of mercury contamination due to a chloro-alkali plant that was active during 12 years. Twenty-six surface sediment samples were collected from the area and mercury concentrations were measured by cold vapour atomic absorption spectrophotometry. A contour map was constructed from the results, indicating that mercury accumulated in a "hot spot" where concentrations reach more than 1 µg g-1. The model is able to estimate mobility of mercury in the sediments based on the distances between iso-concentration contours that determines an attenuation of concentrations factor. Values of attenuation ranged between 0.0729 (East of the hot spot, indicating higher mobility) to 0.7727 (North of the hot spot, indicating lower mobility).

Parametrització de contorns oberts

Un dels principals problemes quan es realitza un anàlisi de contorns és la gran quantitat de dades implicades en la descripció de la figura. Per resoldre aquesta problemàtica, s’aplica la parametrització que consisteix en obtenir d’un contorn unes dades representatives amb els mínims coeficients possibles, a partir dels quals es podrà reconstruir de nou sense pèrdues molt evidents d’informació. En figures de contorns tancats, la parametrització més estudiada és l’aplicació de la transformada discreta de Fourier (DFT). Aquesta s’aplica a la seqüència de valors que descriu el comportament de les coordenades x i y al llarg de tots els punts que formen el traç. A diferència, en els contorns oberts no es pot aplicar directament la DFT ja que per fer-ho es necessita que el valor de x i de y siguin iguals tan en el primer punt del contorn com en l’últim. Això és degut al fet que la DFT representa sense error senyals periòdics. Si els senyals no acaben en el mateix punt, representa que hi ha una discontinuïtat i apareixen oscil·lacions a la reconstrucció. L’objectiu d’aquest treball és parametritzar contorns oberts amb la mateixa eficiència que s’obté en la parametrització de contorns tancats. Per dur-ho a terme, s’ha dissenyat un programa que permet aplicar la DFT en contorns oberts mitjançant la modificació de les seqüencies de x i y. A més a més, també utilitzant el programari Matlab s’han desenvolupat altres aplicacions que han permès veure diferents aspectes sobre la parametrització i com es comporten els Descriptors El·líptics de Fourier (EFD). Els resultats obtinguts han demostrat que l’aplicació dissenyada permet la parametrització de contorns oberts amb compressions òptimes, fet que facilitarà l’anàlisi quantitatiu de formes en camps com l’ecologia, medicina, geografia, entre d’altres.

Estudio teórico de la isomerización del ácido maleico en ácido fumárico: un enfoque basado en el concepto de superficie de energía potencial

A comparative study based on potential energy surfaces (PES) of 2-butanedioic and hypothetic 2-butanedioic/HCl acids is useful for understanding the maleic acid isomerization. The PES enables locating conformers of minimum energy, intermediates of reactions and transition states. From contour diagrams, a set of possible reaction paths are depicted interconnecting the proposed structures. The study was carried out in absentia and in the presence of the catalyst (HCl), using an solvatation model provided by the Gaussian software package. Clearly, the effect of HCl is given by new reaction paths with lower energetic barriers in relation to the reaction without catalyzing.

Comparison Structure Analysis

This study presents an automatic, computer-aided analytical method called Comparison Structure Analysis (CSA), which can be applied to different dimensions of music. The aim of CSA is first and foremost practical: to produce dynamic and understandable representations of musical properties by evaluating the prevalence of a chosen musical data structure through a musical piece. Such a comparison structure may refer to a mathematical vector, a set, a matrix or another type of data structure and even a combination of data structures. CSA depends on an abstract systematic segmentation that allows for a statistical or mathematical survey of the data. To choose a comparison structure is to tune the apparatus to be sensitive to an exclusive set of musical properties. CSA settles somewhere between traditional music analysis and computer aided music information retrieval (MIR). Theoretically defined musical entities, such as pitch-class sets, set-classes and particular rhythm patterns are detected in compositions using pattern extraction and pattern comparison algorithms that are typical within the field of MIR. In principle, the idea of comparison structure analysis can be applied to any time-series type data and, in the music analytical context, to polyphonic as well as homophonic music. Tonal trends, set-class similarities, invertible counterpoints, voice-leading similarities, short-term modulations, rhythmic similarities and multiparametric changes in musical texture were studied. Since CSA allows for a highly accurate classification of compositions, its methods may be applicable to symbolic music information retrieval as well. The strength of CSA relies especially on the possibility to make comparisons between the observations concerning different musical parameters and to combine it with statistical and perhaps other music analytical methods. The results of CSA are dependent on the competence of the similarity measure. New similarity measures for tonal stability, rhythmic and set-class similarity measurements were proposed. The most advanced results were attained by employing the automated function generation – comparable with the so-called genetic programming – to search for an optimal model for set-class similarity measurements. However, the results of CSA seem to agree strongly, independent of the type of similarity function employed in the analysis.

Utilização de surfactantes, na polpação kraft de madeira de eucalipto, como auxiliar na remoção de extrativos lipofílicos

Problemas de deposição de "pitch" em fábricas de celulose e de papel são atribuídos aos extrativos lipofílicos existentes na madeira. Uma das maneiras mais eficientes de controlar essa deposição é através da remoção de seus precursores do sistema, logo que possível, nas etapas de cozimento, lavagem da polpa marrom e pré-deslignificação com oxigênio. O uso de surfactantes como aditivos da polpação tem sido investigado, mas há grande deficiência de informações técnicas, e a aplicação industrial é, ainda, incipiente. A proposta deste trabalho foi analisar a viabilidade de minimizar a deposição de "pitch", intensificando a remoção de suas substâncias precursoras na etapa de polpação pelo uso de tensoativos sintéticos com propriedades umectantes e solubilizantes. Foram testados 20 princípios ativos de surfactantes em cozimento kraft convencional de madeira de eucalipto. Os resultados, alguns estatisticamente significativos, apontaram redução do teor de substâncias lipofílicas na polpa marrom. Foi observado que a remoção dos extrativos lipofílicos da madeira é afetada, inversamente, pelo teor de óxido de eteno na molécula do surfactante. Outros parâmetros de cozimento, como deslignificação, rendimento, teor de rejeitos e viscosidade da polpa, foram também avaliados.

Wood as a model material for medical biomaterials. In vivo and in vitro studies with bone and Betula pubescens Ehrh

Novel biomaterials are needed to fill the demand of tailored bone substitutes required by an ever‐expanding array of surgical procedures and techniques. Wood, a natural fiber composite, modified with heat treatment to alter its composition, may provide a novel approach to the further development of hierarchically structured biomaterials. The suitability of wood as a model biomaterial as well as the effects of heat treatment on the osteoconductivity of wood was studied by placing untreated and heat‐treated (at 220 C , 200 degrees and 140 degrees for 2 h) birch implants (size 4 x 7mm) into drill cavities in the distal femur of rabbits. The follow‐up period was 4, 8 and 20 weeks in all in vivo experiments. The flexural properties of wood as well as dimensional changes and hydroxyl apatite formation on the surface of wood (untreated, 140 degrees C and 200 degrees C heat‐treated wood) were tested using 3‐point bending and compression tests and immersion in simulated body fluid. The effect of premeasurement grinding and the effect of heat treatment on the surface roughness and contour of wood were tested with contact stylus and non‐contact profilometry. The effects of heat treatment of wood on its interactions with biological fluids was assessed using two different test media and real human blood in liquid penetration tests. The results of the in vivo experiments showed implanted wood to be well tolerated, with no implants rejected due to foreign body reactions. Heat treatment had significant effects on the biocompatibility of wood, allowing host bone to grow into tight contact with the implant, with occasional bone ingrowth into the channels of the wood implant. The results of the liquid immersion experiments showed hydroxyl apatite formation only in the most extensively heat‐treated wood specimens, which supported the results of the in vivo experiments. Parallel conclusions could be drawn based on the results of the liquid penetration test where human blood had the most favorable interaction with the most extensively heat‐treated wood of the compared materials (untreated, 140 degrees C and 200 degrees C heat‐treated wood). The increasing biocompatibility was inferred to result mainly from changes in the chemical composition of wood induced by the heat treatment, namely the altered arrangement and concentrations of functional chemical groups. However, the influence of microscopic changes in the cell walls, surface roughness and contour cannot be totally excluded. The heat treatment was hypothesized to produce a functional change in the liquid distribution within wood, which could have biological relevance. It was concluded that the highly evolved hierarchical anatomy of wood could yield information for the future development of bulk bone substitutes according to the ideology of bioinspiration. Furthermore, the results of the biomechanical tests established that heat treatment alters various biologically relevant mechanical properties of wood, thus expanding the possibilities of wood as a model material, which could include e.g. scaffold applications, bulk bone applications and serving as a tool for both mechanical testing and for further development of synthetic fiber reinforced composites.

St. Petersburg Court Chant and the Tradition of Eastern Slavic Church Singing

The present study examines the repertory of liturgical chant known as St. Petersburg Court Chant which emerged within the Imperial Court of St. Petersburg, Russia, and appeared in print in a number of revisions during the course of the 19th century, eventually to spread throughout the Russian Empire and even abroad. The study seeks answers to questions on the essence and composition of Court Chant, its history and liturgical background, and most importantly, its musical relationship to other repertories of Eastern Slavic chant. The research questions emerge from previous literary accounts of Court Chant (summarized in the Introduction), which have tended to be inaccurate and generally not based on critical research. The study is divided into eight main chapters. Chapter 1 provides a survey of the history of Eastern Slavic chant and the Imperial Court Chapel of St. Petersburg until 1917, with special emphasis on the history of singing traditional chant in polyphony, the status of the Court Chapel as a government authority, and its endeavours in publishing church music. Chapter 2 deals with the liturgical background of Eastern chant, the chant genres, and main repertories of Eastern Slavic chant. Chapter 3 concentrates on chant sources: it introduces the musical notations utilised, after which a typology of chant books is presented. The discussion continues with a survey of the sources of Court Chant and their content, the specimens selected for closer analysis, the comparative materials from other repertories, and ends with a commentary on some chant sources that have been excluded. The comparative sources include a specimen from around the beginning of the 12th century, a few manuscripts from the 17th century, and printed and manuscript chant books from the early 18th to early 20th century, covering the geographical area that delimits to the western Ukraine, Astrakhan, Nizhny Novgorod, and the Solovetsky Monastery. Chapter 4 presents the approach and methods used in the subsequent analytical comparisons. After a survey of the pitch organization of Eastern Slavic chant, the customary harmonization strategy of traditional chant polyphony is examined, according to which a method for meaningful analysis of the harmony is proposed. The method is based on the observation that the harmonic framework of chant polyphony derives from the standard pitch collection of monodic chant known as the Church Gamut, specific pitches of which form eight harmonic regions that behave like the usual tonalities of major and harmonic minor. Because of the considerable quantity of comparative chant forms, computer-assisted statistical methods are applied to the analysis of chant melodies. The primary chant forms and their respective comparative forms have been pre-processed into reduced chant prototypes and divided into redactions. The analyses are carried out by measuring the formal dissimilarities of the primary chant forms of the Court Chant repertory against each comparative form, and also by measuring the reciprocal dissimilarities of all chant versions in a redaction, the results of which are subjected to agglomerative hierarchical clustering in order to find out how the chant forms relate to each other. The dissimilarities are determined by applying a metric dissimilarity function that is based on the Levenshtein Distance. Chapter 5 provides the melodic and harmonic analyses of generic chants (chants used for multiple texts of different lengths), i.e., chants for stichera samoglasny and troparia, Chapter 6 of pseudo-generic chants (chants that are used for multiple texts but with certain restrictions), i.e., chants for heirmoi, prokeimena, and three other hymns, and Chapter 7 of non-generic chants, covering nine chants that in the Court repertory are not shared by multiple texts. The results are summarized and evaluated in Chapter 8. Accordingly, it can be established that, contrary to previous conceptions, melodically, Court Chant is in effect a full part of the wider Eastern Slavic chant tradition. Even if it is somewhat detached from the chant versions of the Synodal square-note chant books and the local tradition of Moscow, it is particularly close to chant forms of East Ukraine and some vernacular repertories from Russia. Respectively, the harmonization strategies of Court Chant do not show significant individuality in comparison with those of the available polyphonic comparative sources, the main difference being the part-writing, which generally conforms to western common practice standard, whereas the deviations from this tend to be more significant in other analysed repertories of polyphonic chant. Thus, insofar as the subsequent prevalence of Court Chant is not based on its forceful dissemination by authorities (as suggested in previous literature but for which little tangible evidence could be found in Chapter 1), in the present author’s interpretation, Court Chant attained its dominance principally because musically it was considered sufficiently traditional, and as a chant body supported by the government, was conveniently available in print in serviceable harmonizations.

Vocalization data mining for estimating swine stress conditions

This study aimed to identify differences in swine vocalization pattern according to animal gender and different stress conditions. A total of 150 barrow males and 150 females (Dalland® genetic strain), aged 100 days, were used in the experiment. Pigs were exposed to different stressful situations: thirst (no access to water), hunger (no access to food), and thermal stress (THI exceeding 74). For the control treatment, animals were kept under a comfort situation (animals with full access to food and water, with environmental THI lower than 70). Acoustic signals were recorded every 30 minutes, totaling six samples for each stress situation. Afterwards, the audios were analyzed by Praat® 5.1.19 software, generating a sound spectrum. For determination of stress conditions, data were processed by WEKA® 3.5 software, using the decision tree algorithm C4.5, known as J48 in the software environment, considering cross-validation with samples of 10% (10-fold cross-validation). According to the Decision Tree, the acoustic most important attribute for the classification of stress conditions was sound Intensity (root node). It was not possible to identify, using the tested attributes, the animal gender by vocal register. A decision tree was generated for recognition of situations of swine hunger, thirst, and heat stress from records of sound intensity, Pitch frequency, and Formant 1.

Vocalization of broilers can be used to identify their sex and genetic strain

In order to reach higher broiler performance, farmers target losses reduction. One way to make this possible is by rearing sexed broilers as male and female present diverse performance due to their physiological differences. Birds from different genetic strain also have a distinct performance at the same age. Considering that sexed flocks may present higher performance this study aimed to identify one-day-old chicks’ sex throughout their vocalization. This research also investigated the possibility of identifying the genetic strain by their vocalization attributes. A total of 120 chicks, half of them were from Cobb® genetic strain and the other half from Ross® genetic strain. From each group, a total of 30 were males and 30 females, which were previously separated by sex using their secondary physiological characteristics at the hatchery. Vocalizations audio recording was done inside a semi-anechoic chamber using a unidirectional microphone connected to an audio input of a digital recorder. Vocalizations were recorded for two minutes. Acoustic characteristics of the sounds were analyzed being calculated the fundamental frequency Pitch, the sound intensity, the first formant, and second formant. Results indicated that the vocalizations of both sexes could be identified by the second formant, and the genetic strain was detected by both the second formant and the Pitch.

Kahden merkkijonon pisimmän yhteisen alijonon ongelma ja sen ratkaiseminen

Tämä tutkielma kuuluu merkkijonoalgoritmiikan piiriin. Merkkijono S on merkkijonojen X[1..m] ja Y[1..n] yhteinen alijono, mikäli se voidaan muodostaa poistamalla X:stä 0..m ja Y:stä 0..n kappaletta merkkejä mielivaltaisista paikoista. Jos yksikään X:n ja Y:n yhteinen alijono ei ole S:ää pidempi, sanotaan, että S on X:n ja Y:n pisin yhteinen alijono (lyh. PYA). Tässä työssä keskitytään kahden merkkijonon PYAn ratkaisemiseen, mutta ongelma on yleistettävissä myös useammalle jonolle. PYA-ongelmalle on sovelluskohteita – paitsi tietojenkäsittelytieteen niin myös bioinformatiikan osa-alueilla. Tunnetuimpia niistä ovat tekstin ja kuvien tiivistäminen, tiedostojen versionhallinta, hahmontunnistus sekä DNA- ja proteiiniketjujen rakennetta vertaileva tutkimus. Ongelman ratkaisemisen tekee hankalaksi ratkaisualgoritmien riippuvuus syötejonojen useista eri parametreista. Näitä ovat syötejonojen pituuden lisäksi mm. syöttöaakkoston koko, syötteiden merkkijakauma, PYAn suhteellinen osuus lyhyemmän syötejonon pituudesta ja täsmäävien merkkiparien lukumäärä. Täten on vaikeaa kehittää algoritmia, joka toimisi tehokkaasti kaikille ongelman esiintymille. Tutkielman on määrä toimia yhtäältä käsikirjana, jossa esitellään ongelman peruskäsitteiden kuvauksen jälkeen jo aikaisemmin kehitettyjä tarkkoja PYAalgoritmeja. Niiden tarkastelu on ryhmitelty algoritmin toimintamallin mukaan joko rivi, korkeuskäyrä tai diagonaali kerrallaan sekä monisuuntaisesti prosessoiviin. Tarkkojen menetelmien lisäksi esitellään PYAn pituuden ylä- tai alarajan laskevia heuristisia menetelmiä, joiden laskemia tuloksia voidaan hyödyntää joko sellaisinaan tai ohjaamaan tarkan algoritmin suoritusta. Tämä osuus perustuu tutkimusryhmämme julkaisemiin artikkeleihin. Niissä käsitellään ensimmäistä kertaa heuristiikoilla tehostettuja tarkkoja menetelmiä. Toisaalta työ sisältää laajahkon empiirisen tutkimusosuuden, jonka tavoitteena on ollut tehostaa olemassa olevien tarkkojen algoritmien ajoaikaa ja muistinkäyttöä. Kyseiseen tavoitteeseen on pyritty ohjelmointiteknisesti esittelemällä algoritmien toimintamallia hyvin tukevia tietorakenteita ja rajoittamalla algoritmien suorittamaa tuloksetonta laskentaa parantamalla niiden kykyä havainnoida suorituksen aikana saavutettuja välituloksia ja hyödyntää niitä. Tutkielman johtopäätöksinä voidaan yleisesti todeta tarkkojen PYA-algoritmien heuristisen esiprosessoinnin lähes systemaattisesti pienentävän niiden suoritusaikaa ja erityisesti muistintarvetta. Lisäksi algoritmin käyttämällä tietorakenteella on ratkaiseva vaikutus laskennan tehokkuuteen: mitä paikallisempia haku- ja päivitysoperaatiot ovat, sitä tehokkaampaa algoritmin suorittama laskenta on.