144 research outputs found

    Quantification of aeroacoustic noise sources from wind turbines

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    One of the major environmental concerns regarding wind energy is an increase in noise levels, both in the atmosphere and the ocean. In this study, the generation and propagation of aeroacoustic noise from wind turbines were studied using available measurements together with several signal processing tools, as well as some well-known models within the field. The thesis starts by introducing some general and more advanced concepts regarding wind energy and aeroacoustics. Observational measurements conducted in a gust wind tunnel on a scaled wind turbine model were used to quantify noise characteristics from wind turbines. The experiment was conducted using 48 microphones in a ring array, with a known distance from the source. Then, a simple beamforming algorithm based on delay-and-sum in both 1D and 2D has been applied to identify the distribution of acoustic source strength on the turbine blade and subregions. An open-source program for the Amiet model was adjusted for studying the turbulence interaction and noise generation on the same NACA4412-airfoil, with some simplifications applied. Next, the low-frequency Parabolic Equation model (PE-model) for an inhomogeneous atmosphere was used to study the effect of different atmospheric stability conditions on noise propagation from a wind turbine. Tests for three stability conditions (stable, neutral, and unstable) for variations of source frequencies, as well as for different topography were presented and discussed. The studies conducted in this thesis illustrate the complexity of aeroacoustic noise and the different parts that need to be accounted for in the development of new wind farms, both onshore and offshore.MasteroppgÄve i energiENERGI399

    Geologic controls on fluid flow and seismic imaging of faults in carbonate rocks : Insights from quantitative outcrop analysis and reflection seismic modeling

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    Utforsking av undergrunnen har historisk sett hovudsakleg vore drive av Þkonomiske insentiv gjennom leiting etter hydrokarbon og andre geologiske ressursar. I nyare tid, derimot, har geologiens rolle i det grÞne skiftet fÄtt aukande fokus. Undergrunnen er svÊrt viktig for blant anna CO2- og hydrogenlagring, grunnvassressursar og geotermisk energi, og avgjerande for alle disse bruksomrÄda er strukturar som forkastingar og sprekkenettverk, og deira kontroll pÄ vÊskestraum i undergrunnen. Hovudfokuset i denne avhandlinga er Ä forbetre forstÄinga av undergrunnen gjennom to overordna tema; (i) kontrollen forkastings- og sprekkenettverk har pÄ vÊskestraum og reaksjonar mellom vÊsker og bergartar, og (ii) seismisk avbilding av slike forkastingar og deira vÊske-bergart reaksjonsprodukt i undergrunnen. SjÞlv om det er generell einigheit i at geologiske strukturer utÞver sterk kontroll pÄ vÊskestraum, har fÄ forsÞkt Ä kvantifisere dette forholdet. I samsvar med tema (i) ovanfor byrjar denne avhandlinga difor med Ä kvantifisere og visualisere forholdet mellom vÊskestraum og strukturell kompleksitet (Artikkel 1). Ved hjelp av sementerte haugar med lav porÞsitet som bevis for paleo-vÊskestraum, nyttast topologi for Ä karakterisere og visualisere strukturell kompleksitet i lokaliserte omrÄde, og kvantitativt dokumentere deira korrelasjon med omrÄder for lokalisert paleo-vÊskestraum. Artikkel 2 gir ei oversikt over geologiske kontrollar pÄ vÊskestraum i sedimentÊre bergartar, basert pÄ ein kombinasjon av litteraturanalyse og studie av eksempel frÄ felt der jernoksidutfelling blir brukt som bevis for paleo-vÊskestraum. Artikkelen dokumenterer eit vidt spenn av kontrollar pÄ vÊskestraum og inkluderer alt frÄ enkle geologiske heterogeniteter til meir komplekse nettverk av strukturar, og dokumenterer og kvantifiserer topologien til bÄde sprekkenettverk og hybridnettverk bestÄande av ein kombinasjon av sprekker og sedimentÊre avsetningsstrukturar som fungerer som leiarar for vÊskestraum. Eit viktig verktÞy for kartlegging av slike vÊskeleiande strukturar i undergrunnen er seismiske refleksjonsdata. I trÄd med Tema (ii), undersÞkjer Artikkel 3 effekten av smÄskala forkastingar (nÊr eller under seismisk opplÞysing) pÄ seismiske bilde ved hjelp av seismisk modellering. HovudmÄlet i denne artikkelen er Ä dokumentere effekten som forkastingar under- eller pÄ grensa til seismisk opplÞysing kan ha pÄ seismiske data. For eksempel illustrerer artikkelen korleis subtile forandringar i ein refleksjon kan vere resultat av smÄ forkastingar i undergrunnen, noko som er viktig ny innsikt og som mogleg kan bidra til Ä forbetre tolking av strukturar i seismikk. I tillegg til avbilding av forkastingar i seg sjÞlv, er ogsÄ produkta av vÊske-bergart interaksjon av interesse, og det er derfor viktig Ä ogsÄ forstÄ deira seismiske signatur. Ved hjelp av seismisk modellering av forkastingskontrollerte dolomittar i ei kalksteinsdominert sone i Suezbukta, blir seismisk avbilding av bÄde massive og stratigrafisk kontrollerte dolomittkroppar undersÞkt med varierande geologiske og geofysiske parametrar i Artikkel 4. Resultata i denne artikkelen gir ny innsikt i korleis forkastingskontrollerte hydrotermale dolomittkroppar blir avbilda i seismiske data; artikkelen dokumenterer at dei generelle trendane og nÊrvÊret av dolomitt i undergrunnen er mogleg Ä slutte frÄ seismiske data, men identifisering av individuelle, stratigrafisk kontrollerte dolomittkroppar er ikkje stadfesta mogleg. Funna frÄ denne avhandlinga fremjar den grunnleggande forstÄinga av sentrale geologiske kontrollar pÄ vÊskestraum i undergrunnen, og avbilding av potensielt strÞymingskontrollerande forkastingar og deira bergreaktive produkt i refleksjonsseismiske data. Den nye innsikta presentert i avhandlinga har eit breitt spekter av implikasjonar og nytteomrÄde, for eksempel for lokalisering av Þkonomisk betydelege fÞrekomstar av nyttige mineral, i risikovurdering for CO2- og hydrogenlagring, grunnvasshandtering, lokalisering av forureining, og meir.Exploration of the sub-surface has historically largely been driven by economic incentives through potential hydrocarbon recovery, but more recently the role of subsurface geology in the green shift has gained more focus. The subsurface are highly important for CO2- and hydrogen storage, freshwater resources, and geothermal energy to name a few, and crucial for all these are structures such as faults and their conjugate damage zones, veins, joints, and deformation bands, as well as the depositional architecture of the host rock. This thesis aim to improve our understanding of the sub-surface through two overarching themes, (i) fault and fracture networks and their controls on fluid flow and fluid-rock interaction, and (ii) the seismic imaging of such faults and their fluid-rock reactive products in the subsurface. Despite the consensus that structures exert strong control on fluid flow, few have attempted to quantify this relationship. In accordance with theme (i) above, this thesis therefore starts by quantifying and visualizing the relationship between fluid flow and structural complexity; using low-porosity cemented mounds as a record of paleo-fluid flow and topological characterization, zones of past fluid flow and areas of structural complexity are correlated and documented. Further, an overview of controls on fluid flow is given through literature review and documentation of outcrops using iron oxide precipitates as proxy for paleo-fluid flow; the fluid flow controls are ranging from simple geological heterogeneities to more complex networks of structures, and through topological characterization, the connectivity of fracture networks and hybrid networks are documented. The structures controlling flow can be found at all scales, but as the most commonly used tool for subsurface investigation is seismic imaging many of these will fall below seismic resolution. Following theme (ii), we investigate the effect of sub-seismic faults on seismic imaging using synthetic seismic from outcrop analogues and prove that under the right conditions, faults with throw as low as 5 m still produce distortion of reflections. But not only fault and fractures but also the products of fluid-rock interaction are of interest to explore in the subsurface, and hence it is important to understand their seismic signature. Using seismic modelling of fault-controlled dolomites in a limestone-dominated succession in the Golf of Suez it is found that the presence of both stratabound and massive dolomite bodies can be inferred, although only the massive dolomite can be distinguished individually. The findings form this thesis have implications for the fundamental understanding of how fluids are controlled in the subsurface, and present examples of how these controls might be imaged in reflection seismic data. This is in turn critical for a variety of processes and areas such as locating economically significant ore deposits, hydrocarbon seal risk assessment, prediction of earthquakes, groundwater management, and more. Due to the vast number of processes that are controlled by sub-surface fluid flow it is of both environmental, societal, and economic interest to be able to predict and understand fluid flow pathways, how they interact to form networks, and how they and their fluid-rock interactive products might be portrayed in reflection seismic data.Doktorgradsavhandlin

    OperatĂžrgrensesnitt, topside kommunikasjon for fjernstyrt undervannsfartĂžy og styring av ROV og Manipulator.

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    Denne bacheloroppgaven innebar utvikling av et overflatesystem for et fjernstyrt undervannsfartĂžy (ROV) som ble skapt av tverrfaglige grupper i studentorganisasjonen UiS Subsea. ROV-en ble utformet for Ă„ oppfylle betingelsene for MATE-konkurransen, som arrangeres i Colorado, USA, tidlig pĂ„ sommeren. Overflatesystemet krevde tre hovedimplementeringer for Ă„ oppfylle sitt formĂ„l. Det fĂžrste var en etablert forbindelse mellom overflate og undervannsdelen ved hjelp av UDP og TCP. Det andre var Ă„ legge til manĂžvreringsmuligheter for ROV-en og manipulatoren ved bruk av kontrollere. Det tredje var det grafiske brukergrensesnittet (GUI) for Ă„ presentere all relevant informasjon fra ROV-en. Systemet var modulĂŠrt, noe som innebar at det var enkelt Ă„ endre og implementere nye funksjoner. Det var basert pĂ„ fjorĂ„rets overflatesystem, men har blitt betydelig endret pĂ„ grunn av andre behov og krav. Det hadde en god struktur, med effektive klasser. Prosjektet ble delt inn i deloppgaver for Ă„ forenkle implementeringsprosessen og Ăžke effektiviteten. Denne tilnĂŠrmingen resulterte i det endelige produktet - overflatesystemet. ROV-en var styrbar, GUI-et viste nĂždvendig informasjon, og dataflyten fungerte bra. Systemet vil bli ytterligere forbedret i forkant av MATE-konkurransen, men dette vil ikke bli inkludert i bacheloroppgaven da endringene vil bli gjort etter fristen for innlevering av oppgaven.This bachelor thesis consisted of creating a topside system for a remotely operated vehicle (ROV) that was created by interdisciplinary groups in the student organization UiS Subsea. The ROV was created to satisfy the conditions for the MATE competition, which takes place in Colorado, USA, in early summer. The topside system required three main implementations to fulfill its purpose, the first being an established connection between the topside and subside using UDP and TCP, the second was adding maneuverability to the ROV and Manipulator with the use of controllers, and the third being the graphical user interface (GUI) to present all the relevant information from the ROV. The system was modular, which meant it was easy to change and implement functionalities. It was based on last year’s topside system but has been changed significantly because of other needs and requirements. It had a good structure, with well-functioning classes. The project was broken down into sub-tasks to simplify the implementation process and increase efficiency. This approach resulted in the total final product - the topside system. The ROV was controllable, the GUI displayed the necessary information, and the data flow worked well. The system will be further improved toward the MATE competition, which will not be included in the bachelor as the changes will be made after the bachelor thesis deadline

    OperatĂžrgrensesnitt, topside kommunikasjon for fjernstyrt undervannsfartĂžy og styring av ROV og Manipulator.

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    Denne bacheloroppgaven innebar utvikling av et overflatesystem for et fjernstyrt undervannsfartĂžy (ROV) som ble skapt av tverrfaglige grupper i studentorganisasjonen UiS Subsea. ROV-en ble utformet for Ă„ oppfylle betingelsene for MATE-konkurransen, som arrangeres i Colorado, USA, tidlig pĂ„ sommeren. Overflatesystemet krevde tre hovedimplementeringer for Ă„ oppfylle sitt formĂ„l. Det fĂžrste var en etablert forbindelse mellom overflate og undervannsdelen ved hjelp av UDP og TCP. Det andre var Ă„ legge til manĂžvreringsmuligheter for ROV-en og manipulatoren ved bruk av kontrollere. Det tredje var det grafiske brukergrensesnittet (GUI) for Ă„ presentere all relevant informasjon fra ROV-en. Systemet var modulĂŠrt, noe som innebar at det var enkelt Ă„ endre og implementere nye funksjoner. Det var basert pĂ„ fjorĂ„rets overflatesystem, men har blitt betydelig endret pĂ„ grunn av andre behov og krav. Det hadde en god struktur, med effektive klasser. Prosjektet ble delt inn i deloppgaver for Ă„ forenkle implementeringsprosessen og Ăžke effektiviteten. Denne tilnĂŠrmingen resulterte i det endelige produktet - overflatesystemet. ROV-en var styrbar, GUI-et viste nĂždvendig informasjon, og dataflyten fungerte bra. Systemet vil bli ytterligere forbedret i forkant av MATE-konkurransen, men dette vil ikke bli inkludert i bacheloroppgaven da endringene vil bli gjort etter fristen for innlevering av oppgaven.This bachelor thesis consisted of creating a topside system for a remotely operated vehicle (ROV) that was created by interdisciplinary groups in the student organization UiS Subsea. The ROV was created to satisfy the conditions for the MATE competition, which takes place in Colorado, USA, in early summer. The topside system required three main implementations to fulfill its purpose, the first being an established connection between the topside and subside using UDP and TCP, the second was adding maneuverability to the ROV and Manipulator with the use of controllers, and the third being the graphical user interface (GUI) to present all the relevant information from the ROV. The system was modular, which meant it was easy to change and implement functionalities. It was based on last year’s topside system but has been changed significantly because of other needs and requirements. It had a good structure, with well-functioning classes. The project was broken down into sub-tasks to simplify the implementation process and increase efficiency. This approach resulted in the total final product - the topside system. The ROV was controllable, the GUI displayed the necessary information, and the data flow worked well. The system will be further improved toward the MATE competition, which will not be included in the bachelor as the changes will be made after the bachelor thesis deadline

    OperatĂžrgrensesnitt, topside kommunikasjon for fjernstyrt undervannsfartĂžy og styring av ROV og Manipulator.

    Get PDF
    Denne bacheloroppgaven innebar utvikling av et overflatesystem for et fjernstyrt undervannsfartĂžy (ROV) som ble skapt av tverrfaglige grupper i studentorganisasjonen UiS Subsea. ROV-en ble utformet for Ă„ oppfylle betingelsene for MATE-konkurransen, som arrangeres i Colorado, USA, tidlig pĂ„ sommeren. Overflatesystemet krevde tre hovedimplementeringer for Ă„ oppfylle sitt formĂ„l. Det fĂžrste var en etablert forbindelse mellom overflate og undervannsdelen ved hjelp av UDP og TCP. Det andre var Ă„ legge til manĂžvreringsmuligheter for ROV-en og manipulatoren ved bruk av kontrollere. Det tredje var det grafiske brukergrensesnittet (GUI) for Ă„ presentere all relevant informasjon fra ROV-en. Systemet var modulĂŠrt, noe som innebar at det var enkelt Ă„ endre og implementere nye funksjoner. Det var basert pĂ„ fjorĂ„rets overflatesystem, men har blitt betydelig endret pĂ„ grunn av andre behov og krav. Det hadde en god struktur, med effektive klasser. Prosjektet ble delt inn i deloppgaver for Ă„ forenkle implementeringsprosessen og Ăžke effektiviteten. Denne tilnĂŠrmingen resulterte i det endelige produktet - overflatesystemet. ROV-en var styrbar, GUI-et viste nĂždvendig informasjon, og dataflyten fungerte bra. Systemet vil bli ytterligere forbedret i forkant av MATE-konkurransen, men dette vil ikke bli inkludert i bacheloroppgaven da endringene vil bli gjort etter fristen for innlevering av oppgavenThis bachelor thesis consisted of creating a topside system for a remotely operated vehicle (ROV) that was created by interdisciplinary groups in the student organization UiS Subsea. The ROV was created to satisfy the conditions for the MATE competition, which takes place in Colorado, USA, in early summer. The topside system required three main implementations to fulfill its purpose, the first being an established connection between the topside and subside using UDP and TCP, the second was adding maneuverability to the ROV and Manipulator with the use of controllers, and the third being the graphical user interface (GUI) to present all the relevant information from the ROV. The system was modular, which meant it was easy to change and implement functionalities. It was based on last year’s topside system but has been changed significantly because of other needs and requirements. It had a good structure, with well-functioning classes. The project was broken down into sub-tasks to simplify the implementation process and increase efficiency. This approach resulted in the total final product - the topside system. The ROV was controllable, the GUI displayed the necessary information, and the data flow worked well. The system will be further improved toward the MATE competition, which will not be included in the bachelor as the changes will be made after the bachelor thesis deadline

    The relationship between fluid flow, structures, and depositional architecture in sedimentary rocks: An example-based overview

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    Fluid flow in the subsurface is fundamental in a variety of geological processes including volcanism, metamorphism, and mineral dissolution and precipitation. It is also of economic and societal significance given its relevance, for example, within groundwater and contaminant transport, hydrocarbon migration, and precipitation of ore-forming minerals. In this example-based overview, we use the distribution of iron oxide precipitates as a proxy for palaeofluid flow to investigate the relationship between fluid flow, geological structures, and depositional architecture in sedimentary rocks. We analyse and discuss a number of outcrop examples from sandstones and carbonate rocks in New Zealand, Malta, and Utah (USA), showing controls on fluid flow ranging from simple geological heterogeneities to more complex networks of structures. Based on our observations and review of a wide range of the published literature, we conclude that flow within structures and networks is primarily controlled by structure type (e.g., joint and deformation band), geometry (e.g., length and orientation), connectivity (i.e., number of connections in a network), kinematics (e.g., dilation and compaction), and interactions (e.g., relays and intersections) within the network. Additionally, host rock properties and depositional architecture represent important controls on flow and may interfere to create hybrid networks, which are networks of combined structural and stratal conduits for flow.publishedVersio

    ”Å ha et barn sammen” : Ein studie av fosterforeldre sine forhandlingar med barneverntenesten.

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    Denne studien handlar om kontakta mellom fosterforeldre og barnevernteneste. Bakgrunnen for temaet er at denne kontakta kan ha betyding for kvaliteten pĂ„ fosterheimstiltaka og innverknad pĂ„ fosterbarna sine oppvekstvilkĂ„r. Ved Ă„ ta utgangspunkt i fosterforeldra sine opplevingar, kan forstĂ„inga av kontaktforholdet utvidast. Dermed kan ogsĂ„ handlingsrepertoaret til aktĂžrane i verksemda utvidast. Problemstillinga er som fĂžlgjer: Korleis forstĂ„r fosterforeldra kontakta dei har med barneverntenesten? For Ă„ belyse problemstillinga, har eg intervjua ti fosterforeldre frĂ„ Ă„tte fosterfamiliar om deira erfaringar frĂ„ kontakt med barneverntenesten. Datamaterialet vert konstruert og analysert etter kvalitativ metode med sĂŠrleg vekt pĂ„ omgrepa posisjonering og forhandling. Forhandling vert lagt som ein premiss for studien og er eit overordna analytisk perspektiv. Studien viser ein stor variasjon i fosterforeldra sine opplevingar av samhandling med barneverntenesten. Studien viser ogsĂ„ rĂžrslene i denne samhandlinga ved at endringar i konteksten medfĂžrer endringar i posisjonar og at fosterforeldre ogsĂ„ er med pĂ„ Ă„ skape seg posisjonar. Ulike posisjonar medfĂžrer ulike forhandlingsmĂ„tar. Forhandlingane viser til at betydningar ikkje er fastlagde, men i stadig forandring. Fosterforeldra forhandlar bĂ„de med seg sjĂžlv og barnevernarbeidarane om korleis dei skal forstĂ„ hendingar. Kompetanse og veiledning er to sentrale omrĂ„der i kontakta mellom fosterforeldre og barnevernteneste som eg har sett nĂŠrmare pĂ„. Studien viser at fosterforeldra ser det som viktig at barnevernarbeidaren kjenner barnet og/eller fosterfamilien, og at denne kjennskapen vert sett pĂ„ som det viktigaste grunnlaget for kompetanse hos barnevernarbeidarane. Studien viser ogsĂ„ at fosterforeldra opplever seg som likestilte med barnevernarbeidarane nĂ„r det gjeld kompetanse pĂ„ barna. Dei ser pĂ„ barnevernarbeidarane som kompetente nĂ„r dei anerkjenner fosterforeldra sin posisjon som den som kjenner barnet best og gĂ„r i dialog med dei om barnet sitt beste, forutan Ă„ utfĂžre dei formelle oppgĂ„vene. Fosterforeldra forventar ikkje nĂždvendigvis at barnevernarbeidarane skal ha ekspertkunnskap om barn, men mĂ„ sĂžrgje for Ă„ opprette kontakt med andre instansar nĂ„r barnet viser spesiell Ă„tferd. 6 Fosterforeldra i denne studien oppfattar i utgangspunktet veiledning som rĂ„d om korleis dei skal forholde seg i konkrete situasjonar dei stĂ„r oppe i med barna. Undervegs i intervjua med fosterforeldra reflekterar dei over veiledningsomgrepet, og forstĂ„inga av omgrepet forandrar seg til Ă„ omfatte meir enn konkrete rĂ„d. Studien viser at veiledning handlar om Ă„ reflektere over situasjonar og erfaringar med ein annan person som er i stand til Ă„ ta deira perspektiv.This research study covers the contact and relationship between foster parents and child welfare services. The reason I chose this subject is that this relationship could influence both the quality level of the decisions made to help the foster parents and also the quality of the living conditions of the foster children. By focusing on foster parents’ point of view, the understanding of this two sided relationship could expand and the ways of action increase. The topic sentence is: How do foster parents interpret the relationship they have with the child welfare service? I have interviewed ten different foster parents from eight different families regarding their experience with child welfare services. The research material has been constructed and analyzed using a qualitative method with emphasizes on the concepts positioning and negotiations. Negotiation was a premise for the research project and is an overall analytical perspective. The study shows that there is a variation in foster parents experiences of cooperation with the child welfare services. Furthermore, the study shows the dynamic factor in this cooperation by positions that change with contextual change. Additionally, the study shows that also the foster parents plays a role in achieving their positions in the relationship. Different positions leads to different forms of negotiation. These negotiations indicate the fact that interpretations are not static, but in continuous change. The foster parents negotiate both with themselves and the child welfare employees regarding how to interpret and understand incidents that happens. I have also taken a closer look at the two terms competency and supervising in my study. They are two crucial areas in the relationship and cooperation between foster parents and child welfare. My research shows that foster parents see it as important that the child welfare employee has knowledge about the child under custody and/or the foster family where the child is under custody. According to the foster parents interviewed, this knowledge is considered the most important in the employee’s competency level. Foster parents see themselves as equally knowledgeable about the children as a child welfare official. Furthermore, the study shows that foster parents consider child welfare employees as competent in situations where the employees acknowledge foster parents as the ones who know the foster child the best and communicate with the foster parents about what the child 8 needs, in addition to doing their official tasks. Foster parents don’t necessary expect that the officials should be subject matter experts about children in general, but instead take necessary steps to get in touch with other services when and if the child shows sign of abnormal behavior. The foster parents in this study initially understand supervising as advice of how to behave in specific situations with the child. However, during the interviews I experienced that the foster parents began to reflect more about the content of the term itself, and that their interpretation of supervising was readjusted to a deeper understanding of the term. The study shows that supervising is about being able to reflect on situations and experiences with another person who is able to see things from the foster parents’ perspective.Master i sosialt arbei

    Identifying prostate cancer and its clinical risk in asymptomatic men using machine learning of high dimensional peripheral blood flow cytometric natural killer cell subset phenotyping data

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    We demonstrate that prostate cancer can be identified by flow cytometric profiling of blood immune cell subsets. Herein, we profiled natural killer (NK) cell subsets in the blood of 72 asymptomatic men with Prostate-Specific Antigen (PSA) levels < 20 ng ml-1, of whom 31 had benign disease (no cancer) and 41 had prostate cancer. Statistical and computational methods identified a panel of eight phenotypic features (CD56dimCD16high, CD56+DNAM−1−, CD56+LAIR−1+, CD56+LAIR−1−, CD56brightCD8+, CD56+NKp30+, CD56+NKp30−, CD56+NKp46+) that, when incorporated into an Ensemble machine learning prediction model, distinguished between the presence of benign prostate disease and prostate cancer. The machine learning model was then adapted to predict the D’Amico Risk Classification using data from 54 patients with prostate cancer and was shown to accurately differentiate between the presence of low-/intermediate-risk disease and high-risk disease without the need for additional clinical data. This simple blood test has the potential to transform prostate cancer diagnostics

    Identifying the presence of prostate cancer in individuals with PSA levels <20 ng ml−1 using computational data extraction analysis of high dimensional peripheral blood flow cytometric phenotyping data

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    Determining whether an asymptomatic individual with Prostate-Specific Antigen (PSA) levels below 20 ng ml−1 has prostate cancer in the absence of definitive, biopsy-based evidence continues to present a significant challenge to clinicians who must decide whether such individuals with low PSA values have prostate cancer. Herein, we present an advanced computational data extraction approach which can identify the presence of prostate cancer in men with PSA levels <20 ng ml−1 on the basis of peripheral blood immune cell profiles that have been generated using multi-parameter flow cytometry. Statistical analysis of immune phenotyping datasets relating to the presence and prevalence of key leukocyte populations in the peripheral blood, as generated from individuals undergoing routine tests for prostate cancer (including tissue biopsy) using multi-parametric flow cytometric analysis, was unable to identify significant relationships between leukocyte population profiles and the presence of benign disease (no prostate cancer) or prostate cancer. By contrast, a Genetic Algorithm computational approach identified a subset of five flow cytometry features (CD8+CD45RA−CD27−CD28− (CD8+ Effector Memory cells); CD4+CD45RA−CD27−CD28− (CD4+ Terminally Differentiated Effector Memory Cells re-expressing CD45RA); CD3−CD19+ (B cells); CD3+CD56+CD8+CD4+ (NKT cells)) from a set of twenty features, which could potentially discriminate between benign disease and prostate cancer. These features were used to construct a prostate cancer prediction model using the k-Nearest-Neighbor classification algorithm. The proposed model, which takes as input the set of flow cytometry features, outperformed the predictive model which takes PSA values as input. Specifically, the flow cytometry-based model achieved Accuracy = 83.33%, AUC = 83.40%, and optimal ROC points of FPR = 16.13%, TPR = 82.93%, whereas the PSA-based model achieved Accuracy = 77.78%, AUC = 76.95%, and optimal ROC points of FPR = 29.03%, TPR = 82.93%. Combining PSA and flow cytometry predictors achieved Accuracy = 79.17%, AUC = 78.17% and optimal ROC points of FPR = 29.03%, TPR = 85.37%. The results demonstrate the value of computational intelligence-based approaches for interrogating immunophenotyping datasets and that combining peripheral blood phenotypic profiling with PSA levels improves diagnostic accuracy compared to using PSA test alone. These studies also demonstrate that the presence of cancer is reflected in changes in the peripheral blood immune phenotype profile which can be identified using computational analysis and interpretation of complex flow cytometry datasets

    An experimental study of low-level laser therapy in rat Achilles tendon injury

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    The aim of this controlled animal study was to investigate the effect of low-level laser therapy (LLLT) administered 30 min after injury to the Achilles tendon. The study animals comprised 16 Sprague Dawley male rats divided in two groups. The right Achilles tendons were injured by blunt trauma using a mini guillotine, and were treated with LLLT or placebo LLLT 30 min later. The injury and LLLT procedures were then repeated 15 hours later on the same tendon. One group received active LLLT (λ = 904 nm, 60 mW mean output power, 0.158 W/cm2 for 50 s, energy 3 J) and the other group received placebo LLLT 23 hours after LLLT. Ultrasonographic images were taken to measure the thickness of the right and left Achilles tendons. Animals were then killed, and all Achilles tendons were tested for ultimate tensile strength (UTS). All analyses were performed by blinded observers. There was a significant increase in tendon thickness in the active LLLT group when compared with the placebo group (p < 0.05) and there were no significant differences between the placebo and uninjured left tendons. There were no significant differences in UTS between laser-treated, placebo-treated and uninjured tendons. Laser irradiation of the Achilles tendon at 0.158 W/cm2 for 50 s (3 J) administered within the first 30 min after blunt trauma, and repeated after 15 h, appears to lead to edema of the tendon measured 23 hours after LLLT. The guillotine blunt trauma model seems suitable for inflicting tendon injury and measuring the effects of treatment on edema by ultrasonography and UTS. More studies are needed to further refine this model
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