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Avaliação do teste de imunoperoxidase para detecção de anticorpos contra o vírus da leucose bovina (BLV) / Evaluation of immunoperoxidase test for the detection of antibodies against the bovine leukosis virus (BLV)Castro, Clarissa Caetano de 31 March 2011 (has links)
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Previous issue date: 2011-03-31 / The enzootic bovine leukosis is an illness caused by the bovine leukosis virus (BLV) which provokes a persistent infection in cattle and is responsible for significant economical losses to the bovines, mainly dairy cattle. It is widely spread in Brazilian cattle and it can come up in three forms: asymptomatic infection, persistent lymphocytosis and lymphosarcoma. The animals that have antibodies against the BLV must be eliminated or separated from the rest of the cattle, because they are carriers and disseminators of the virus during all their lifetimes. The diagnosis of this disease is essential for control and eradication strategies based on the segregation of infected animals in order to avoid or attenuate the transmission of the virus, and consequently, minimize the economical losses caused by the disease. During the BLV infection antibodies are produced against the main viral proteins, gp 51, gp 30 (envelope glicoproteins) and p24 (capsid protein). The agar gel immunodiffusion (AGID) and the enzyme-linked immunosorbent assay (ELISA) tests are the most used for diagnosis. In this report the immunoperoxidase technique (peroxidase linked assay - PLA) was evaluated in order to detect antibodies against the BLV. The results obtained in the PLA were compared with the AGID test and the specificity of the positive ones was confirmed by the Western blotting (WB) technique. Two hundred and one bovine serum samples of cattle coming from the city of Pelotas were tested: 59% (119) were positive in PLA and 26% (53) were positive in AGID. All the AGID positive samples were also PLA positive. From the 32,8% (66) of the conflicting serum results just eight were confirmed as positive in WB, indicating that the rest of the results were false-positive and showing that AGID failed in identifying 4% of the BLV positive animals. The PLA technique for the diagnosis of the BLV infection demonstrated to be very useful to use in control programs because it was more sensitive when compared to the AGID technique. However, the occurrence of false-positive results by the PLA makes its use unviable in eradication programs that involve the sacrifice of seropositive animals. / A leucose enzoótica dos bovinos (EBL) é uma enfermidade causada pelo vírus da leucose bovina (BLV), que ocasiona uma infecção persistente em bovinos, e é responsável por perdas econômicas significativas à pecuária, principalmente a leiteira. Amplamente disseminada no rebanho brasileiro, pode ser manifestada de três formas: aleucêmica, linfocitose persistente e linfossarcoma. Os animais com anticorpos contra o BLV deverão ser eliminados ou separados do restante do rebanho, pois significa que são portadores e disseminadores do vírus por toda a vida. O diagnóstico desta doença é essencial para estratégias de controle e erradicação baseadas na segregação de animais infectados no intuito de evitar ou amenizar a transmissão do vírus e, consequentemente, minimizar as perdas econômicas causadas pela doença. Durante a infecção pelo BLV são produzidos anticorpos contra as principais proteínas virais, gp51, gp30 (glicoproteínas do envelope) e p24 (proteína do capsídeo). O teste de imunodifusão em gel de ágar (agar gel immunodiffusion AGID) e o ensaio imunoenzimático (enzyme-linked immunosorbent assay ELISA) são os mais utilizados para diagnóstico. No presente trabalho foi avaliada a técnica de imunoperoxidase (peroxidase linked assay PLA) na detecção de anticorpos contra o BLV. Os resultados obtidos na PLA foram comparados com o teste de AGID e a especificidade dos positivos confirmada pela técnica de Western blotting (WB). Foram testadas 201 amostras de soro de bovinos provenientes de propriedades localizadas no município de Pelotas: 59% (119) foram positivos por PLA e 26% (53) positivos por AGID. Todas as amostras positivas na AGID foram também positivas na PLA. Dos 32,8% (66) dos soros com resultados conflitantes apenas oito foram confirmados como positivos no WB, indicando serem falso-positivos os demais resultados e constatando que a AGID falhou em identificar 4% de animais positivos para EBL. A técnica de PLA para diagnóstico de infecção pelo BLV se mostrou muito útil para uso em programas de controle devido à maior sensibilidade da técnica quando comparada com o teste de AGID. Contudo, a ocorrência de resultados falso-positivos pela PLA inviabiliza o seu uso em programas de erradicação que envolva o sacrifício do animal soropositivo.
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Comparações filogenômicas entre cepas de Listeria monocytogenes isoladas de diferentes fontes e regiões geográficas / PHYLOGENOMIC COMPARISONS BETWEEN Listeria monocytogenes STRAINS ISOLATED FROM DIFFERENT SOURCES AND GEOGRAPHIC REGIONS.Nalério, Élen Silveira 17 November 2009 (has links)
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Previous issue date: 2009-11-17 / Listeria monocytogenes is the causative agent of listeriosis which may cause a
range of diseases from gastroenteritis, meningitis and death. In fact, disease
outcome can be related to strain serotype/lineage thus molecular analyses has
demonstrated that L. monocytogenes is a highly diverse species which can be
grouped into three lineages. Whole-genome microarray can be employed to
study phylogenetic relationships among Listeria strains either species or
serotype level, in addition to demonstrate differences on their virulence potential
and/or environmental adaptation. The aim of this study was the whole genome
comparison of L. monocytogenes strains from different origins. Ninety-nine L.
monocytogenes strains from different geographical origins (Brazil, Denmark,
Austria, Ireland, USA and unknown), including clinical strains (humans and
animals), food and food industries strains were analysed. DNA from all strains
were competitively hybridized on to a L. monocytogenes DNA microarray based
on the whole-genome sequence L. monocytogenes EGD-e. DNA labeling and
hybridization protocol were followed according to Dorrell et al., (2001). Data
acquisition, processing and comparative phylogenomics were performed as
previously described by Stabler et al. (2006). Comparative phylogenomics
clustered the L. monocytogenes strains into two central clades which is
representative of the two main lineages of this species. In addition each of
these clades were divided into two further subclades. Clade formation was
independent of the geographical origin of strains with the exception of the clade
containing persistent strains (strains that persist in food-processing
environment), where none of the Brazilian strains were present. It was found 18
specific genes for lineage I strains (1/2a and 1/2c serotypes). These genes are
related to carbohydrate metabolism, two component regulatory system, ABC
transporter complex and bvrB and bvrC genes. Significantly all persistent
strains clustered together in the same lineage I clade. We achieved a set of
unique genes belonging exclusively to L. monocytogenes persistent strains
pointing to be responsible for its adaptation profile. The genes are involved in
stress resistance and are related to carbohydrate transport and metabolism,
environmental information processing, signal transduction mechanisms, cell
surface protein, amino acid transport and metabolism, nucleotide transport and
metabolism, translation, cell wall biogenesis, replication, recombination and
repair, transport of small molecules similar to ABC transporter, metabolism of
lipids and unknown function. Interestingly from 14 virulence listed genes most of
them were present in all studied L. monocytogenes strains with exception of
inlE and inlG genes. These findings indicate that genetic variability of L.
monocytogenes strains point to niche adaptation instead virulence
differentiation despite of different origins. Persistent strains clustered suggesting
genetic origin to survival in this environment. / Listeria monocytogenes é o agente causador da listeriose, uma infecção severa
que pode cursar com sintomas que variam desde gastroenterites, meningites e
até mesmo a morte. De fato, o desenvolvimento da doença pode ser
relacionado a determinados sorotipos/linhagens das cepas de Listeria. Análises
moleculares dos diferentes sorotipos/linhagens de L. monocytogenes,
demonstraram que esta espécie é amplamente diversa, a qual pode ser
agrupada em três linhagens. O estudo completo de genomas, baseado na
técnica de microarray, pode ser empregado para estudar a relação filogenética
entre cepas de Listeria tanto em nível de espécie, quanto em nível de sorotipo.
Não obstante, a técnica de microarray visa evidenciar as diferenças no
potencial patogênico e/ou adaptativo das cepas. O objetivo deste estudo foi a
comparação filogenética entre cepas de L. monocytogenes isoladas de
diferentes fontes. Foram analisadas 99 cepas de L. monocytogenes de
diferentes origens geográficas (Brasil, Dinamarca, Áustria, Irlanda, Estados
Unidos da América e fontes desconhecidas), incluindo cepas clínicas (humanas
e animais), de alimentos e de indústrias alimentícias. O DNA das cepas teste
foi hibridizado em DNA microarrays de L. monocytogenes baseado em
seqüências do genoma de L. monocytogenes EGD-e. Os protocolos para
marcação e hibridização do DNA seguiram as recomendações de Dorrell et al.,
(2001). A aquisição de dados, o processamento e as comparações
filogenômicas foram realizadas conforme previamente descrito por Stabler et al.
(2006). Comparações filogenômicas agruparam as cepas de L. monocytogenes
em dois clades centrais, os quais são representativos das duas principais
linhagens desta espécie. Além disso, cada um destes clades foram subdivididos
em mais dois sub-clades. A formação dos clades foi independente da
origem geográfica das cepas, com exceção do clade contendo cepas
persistentes (cepas que persistem no ambiente de processamento de
alimentos), onde nenhuma cepa Brasileira esteve presente. Foram identificados
18 genes específicos para as cepas da linhagem I (sorotipos 1/2a e 1/2c).
Esses genes são relacionados ao metabolismo de carboidratos, sistema
regulatório two component, complexo de transporte ABC e aos genes bvrB e
bvrC. A grande maioria das cepas persistentes se agrupou no mesmo clade
pertencente à linhagem I. Foi obtido um conjunto de genes únicos pertencentes
exclusivamente às cepas persistentes de L. monocytogenes, os quais sugerem
serem os responsáveis pelo perfil adaptativo destas cepas. Os genes são
envolvidos em resistência ao estresse e são relacionados ao transporte e
metabolismo de carboidratos, processamento de informação ambiental,
mecanismos de transdução de sinais, proteína de superfície celular, transporte
e metabolismo de aminoácidos, transporte e metabolismo de nucleotídeos,
tradução, biogênese de parede celular, replicação, recombinação e reparo,
transporte de pequenas moléculas similar ao transportador ABC, metabolismo
de lipídios e de função desconhecida. Dos 14 genes de virulência listados a
maioria deles esteve presente em todas as cepas de L. monocytogenes
estudadas, com exceção dos genes inlE e inlG. Estes dados sugerem que,
apesar das distintas origens de isolamento, a variabilidade genética das cepas
de L. monocytogenes é direcionada para adaptação ambiental, ao invés da
diferenciação visando virulência.
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Architectural Principles for Database Systems on Storage-Class MemoryOukid, Ismail 23 January 2018 (has links) (PDF)
Database systems have long been optimized to hide the higher latency of storage media, yielding complex persistence mechanisms. With the advent of large DRAM capacities, it became possible to keep a full copy of the data in DRAM. Systems that leverage this possibility, such as main-memory databases, keep two copies of the data in two different formats: one in main memory and the other one in storage. The two copies are kept synchronized using snapshotting and logging. This main-memory-centric architecture yields nearly two orders of magnitude faster analytical processing than traditional, disk-centric ones. The rise of Big Data emphasized the importance of such systems with an ever-increasing need for more main memory. However, DRAM is hitting its scalability limits: It is intrinsically hard to further increase its density.
Storage-Class Memory (SCM) is a group of novel memory technologies that promise to alleviate DRAM’s scalability limits. They combine the non-volatility, density, and economic characteristics of storage media with the byte-addressability and a latency close to that of DRAM. Therefore, SCM can serve as persistent main memory, thereby bridging the gap between main memory and storage. In this dissertation, we explore the impact of SCM as persistent main memory on database systems. Assuming a hybrid SCM-DRAM hardware architecture, we propose a novel software architecture for database systems that places primary data in SCM and directly operates on it, eliminating the need for explicit IO. This architecture yields many benefits: First, it obviates the need to reload data from storage to main memory during recovery, as data is discovered and accessed directly in SCM. Second, it allows replacing the traditional logging infrastructure by fine-grained, cheap micro-logging at data-structure level. Third, secondary data can be stored in DRAM and reconstructed during recovery. Fourth, system runtime information can be stored in SCM to improve recovery time. Finally, the system may retain and continue in-flight transactions in case of system failures.
However, SCM is no panacea as it raises unprecedented programming challenges. Given its byte-addressability and low latency, processors can access, read, modify, and persist data in SCM using load/store instructions at a CPU cache line granularity. The path from CPU registers to SCM is long and mostly volatile, including store buffers and CPU caches, leaving the programmer with little control over when data is persisted. Therefore, there is a need to enforce the order and durability of SCM writes using persistence primitives, such as cache line flushing instructions. This in turn creates new failure scenarios, such as missing or misplaced persistence primitives.
We devise several building blocks to overcome these challenges. First, we identify the programming challenges of SCM and present a sound programming model that solves them. Then, we tackle memory management, as the first required building block to build a database system, by designing a highly scalable SCM allocator, named PAllocator, that fulfills the versatile needs of database systems. Thereafter, we propose the FPTree, a highly scalable hybrid SCM-DRAM persistent B+-Tree that bridges the gap between the performance of transient and persistent B+-Trees. Using these building blocks, we realize our envisioned database architecture in SOFORT, a hybrid SCM-DRAM columnar transactional engine. We propose an SCM-optimized MVCC scheme that eliminates write-ahead logging from the critical path of transactions. Since SCM -resident data is near-instantly available upon recovery, the new recovery bottleneck is rebuilding DRAM-based data. To alleviate this bottleneck, we propose a novel recovery technique that achieves nearly instant responsiveness of the database by accepting queries right after recovering SCM -based data, while rebuilding DRAM -based data in the background. Additionally, SCM brings new failure scenarios that existing testing tools cannot detect. Hence, we propose an online testing framework that is able to automatically simulate power failures and detect missing or misplaced persistence primitives. Finally, our proposed building blocks can serve to build more complex systems, paving the way for future database systems on SCM.
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Fysioterapeutstudenters förhållningssätt till samband mellan funktionsnedsättning och långvarig ryggsmärtaStenman, Adam, Magnusson, Peter January 2017 (has links)
Bakgrund: Patienter med långvarig ländryggssmärta upplever ofta funktionsnedsättning, utan att där finns en tydlig koppling till vävnadsskada. Funktionsnedsättning kan delvis vara skapad av vården, av att patienter har fått kontraproduktiva råd av vårdgivare. Syfte: Att undersöka attityder och attitydskillnader mellan studenter i termin 1 och 6 på fysioterapeutprogrammet vid Uppsala Universitet gällande kopplingen mellan långvarig ländryggssmärta och funktionsnedsättning, samt om den egna upplevelsen av smärta påverkar resultatet. Metod: Studenter i termin 1 respektive 6 på fysioterapeutprogrammet vid Uppsala Universitet svarade på Health Care Providers Pain and Impairment Relationship Scale (HC-PAIRS). HC-PAIRS mäter i hur stor utsträckning vårdpersonal associerar funktionsnedsättning med långvarig icke-specifik ländryggssmärta. Resultat: Termin 6 svarade signifikant lägre än termin 1, vilket betyder att studenterna i termin 1 har mer negativa förväntningar på funktionsförmågan hos patienter med ländryggssmärta (55 mot 46). Signifikanta skillnader fanns inom områdena “förväntningar på funktion”, “förväntningar på social förmåga” och “behov av bot”, men inte inom “projicerad kognition”. Egen upplevelse av smärta påverkade inte resultatet. Slutsats: Studenter i termin 6 har ett mer positivt synsätt på funktionsförmågan hos patienter med långvarig ländryggssmärta än studenter i termin 1. Spridningen är dock stor i båda terminerna. / Background: Patients with persistent spinal pain often experience a loss of function, without a clear association with tissue damage. Loss of function may partly be healthcare caused, after patients being provided counterproductive advice by their caregiver. Purpose: To investigate the differences in attitudes among first term and last term physical therapy students at Uppsala University, in regards to persistent spinal pain and loss of function and to investigate if student’s own experience of persistent pain influences these attitudes. Method: The students answered the Health Care Providers Pain and Impairment Relations Scale (HC-PAIRS) Questionnaire. HC-PAIRS measures to what extent health care providers link loss of function to persistent spinal pain. Results: There was a significant difference between the semesters. The students in semester one having a higher overall score compared to the students in semester six (55,5 compared to 46). There were significant differences regarding “functional expectations”, “social expectations” and “need for cure”, but not in “projected cognition”. The students’ own experiences of persistent pain did not affect their scoring. Conclusion: Students in semester six had a more positive outlook on the functional ability among patients with persistent spinal pain than students in semester one. However, there was a vast spread of results within both semesters.
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Physicochemical characterization and biocompatibility studies of persistent luminescence nanoparticles for preclinical diagnosis applications / Caractérisation physicochimique des nanoparticules à luminescence persistante et étude de leur biocompatibilité pour des applications précliniques de diagnosticRamírez Garcia, Gonzalo 27 July 2016 (has links)
Les nanoparticules (NPs) à luminescence persistante de gallate de zinc dopée chrome (ZnGa1.995Cr0.005 O4) sont des matériaux innovants avec des propriétés optiques particulières qui permettent leur utilisation pour l'imagerie optique in vivo. Leur caractérisation a été effectuée par une méthode émergente dans ce domaine, l'électrophorèse capillaire. Les résultats ont démontré le potentiel de cette méthode pour garantir le contrôle et la qualité des NPs. Un ensemble général des tests de toxicité a été réalisé in vitro et in vivo après administration aiguë, à court et à long terme des ZnGa1.995Cr0.005O4, afin d'évaluer leur biocompatibilité. Lors de l'administration de NPs hydroxylés, différentes conséquences négatives ont été notées, ainsi comme l'effet protecteur du polyéthylène glycol fonctionnalisé en surface des NPs. En raison de l'importance des interactions des NPs avec les protéines plasmatiques lors de leur administration, nous avons évalué et appliqué pour la première fois la méthode électrocinétique de Hummel-Dreyer pour la détermination des interactions non spécifiques entre les NPs PEGylés et des protéines. Finalement, l'évaluation des interactions entre les ZnGa1.995Cr0.005O4 et un système binaire de protéines (albumine et Apolipoprotéine-E) a été effectuée par des méthodes électrocinétiques. Ces analyses ont montré une affinité plus forte entre la surface des NPs PEGylés et l'apolipoprotéine-E par rapport à l'albumine, ce qui pourrait représenter une stratégie novatrice pour la vectorisation des NPs vers la région du cerveau. Toutes les méthodes mentionnées ci-dessus peuvent être extrapolées pour l'analyse des autres NPs avec plusieurs des applications. / The chromium doped zinc gallate (ZnGa1.995Cr0.005O4) nanoparticles (NPs) are innovative materials with specific optical properties, notably the persistent luminescence, which allow their use for in vivo optical imaging. Their characterization was carried out by an emergent method in this area, the capillary electrophoresis. The obtained results demonstrated the potential of this method to ensure the control and quality of NPs. A general set of toxicity tests were performed in vitro and in vivo after acute, short- and long-term administration of the NPs to assess their biocompatibility. Various negative effects were noted upon administration of hydroxylated NPs, as well as the protective effect of NP PEGylation. Because of the importance of NP interactions with plasma proteins after their in vivo administration, we evaluated and applied for the first time the Hummel-Dreyer electrokinetic method for the determination of non-specific interactions between PEGylated NPs and proteins. Finally, the evaluation of the interactions between the ZnGa1.995Cr0.005O4 and a binary system of proteins (albumin and apolipoprotein-E) was carried out by electrokinetic methods. The results revealed greater affinity between the surface of the PEGylated NPs and the apolipoprotein-E compared to albumin, which could represent a novel strategy for the vectorization of NPs towards the brain region. All the above mentioned methods can be extrapolated for the analysis of other NPs with several potential applications.
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The Detection of Amazonian Manatees (Trichechus inunguis) Using Side-Scan Sonar and the Effect of Oil Activities on Their Habitats in Eastern EcuadorBrice, Caitlin E. 01 May 2014 (has links)
Substantial hunting pressure and habitat destruction caused by oil extraction has critically endangered the Amazonian manatee in Ecuador. The current population status is unknown because an effective method to observe them in the wild has yet to be developed. This study explored whether the Amazonian manatee persists or has been extirpated in the eastern Ecuadorian Amazon utilizing side-scan sonar to increase odds of detection. Spatial differences in probability of detection were quantified if manatees were observed. The level of chemical contamination was determined and compared spatially and temporally against historical data. Data were collected using opportunistic transect surveys and grab sampling of surface water in Yasuni National Park, Lagartococha, and Cuyabeno Wildlife Reserve. Surveys confirmed that the manatee population is extant. Manatees were encountered more often in Cuyabeno Wildlife Reserve than in Lagartococha and Yasuni. Side-scan sonar detected more manatees than previously reported in 1996-1999. Side-scan sonar is a viable method for detection of manatees in the Ecuadorian Amazon system and resulted in greater detection as a function of effort. All future population studies should incorporate side-scan sonar. Lead, arsenic, mercury, polynuclear aromatic hydrocarbons [PAHs], and volatile organic compounds [VOCs] were not detected in the waters of the study region. High total petroleum hydrocarbon [TPH] levels were measured in 7 samples from Yasuni National Park. The concentrations of TPH were higher in Yasuni National Park than in Lagartococha and Cuyabeno. TPHs were detected only in the study region with a recent oil spill; there was no evidence that TPHs were higher near oil production wells and pipelines. The concentrations of TPH were significantly different than those measured in 1998 (z =3.01710, p=0.0026). A dedicated study should be performed to develop a protocol for monitoring persistent oil contaminants in the Ecuadorian Amazon and determine their sink.
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Bone toxicity of persistent organic pollutantsFinnilä, M. A. (Mikko A. J.) 29 July 2014 (has links)
Abstract
Persistent organic pollutants (POPs), especially dioxin-like chemicals, have been shown to have adverse effects on skeleton and these effects are likely to be mediated via the aryl hydrocarbon receptor (AHR). In spite of the extensive research, the characteristics of developmental effects of POPs are poorly known and the role of AHR in POP bone toxicity and skeletal development in general.
In this project changes in bone morphology and strength as well as tissue matrix mechanics are studied by applying state of the art biomedical engineering methods. This allows understanding of the effects of dioxins exposure and AHR activity on the development and maturation of extracellular matrix in musculoskeletal tissues from a completely new perspective, and thereby improving the health risk assessment of POPs.
In the present study skeletal properties of rats exposed maternally to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), Northern Contaminant Mixture (NCM) and Aroclor1254 (A1254) were studied for cross-sectional morphometric and biomechanical properties, and data were analysed with benchmark dose modelling. In addition, extracellular matrix properties were analysed using nanoindentation. Similar measurements were performed for adult wild-type and AHR-null mice after TCDD exposure. The same animals were also analysed for microstructural changes using micro-computed tomography and their bone cell activity was estimated from serum markers and gene expression.
Analyses show decreased bone length and cross-sectional properties with consequently decreased bone strength. On the other hand, an increased trabecular BMD in response to NCM and A1254 was observed. In addition, bone matrix properties indicated delayed maturation or early senescence after maternal or adult exposure, respectively. The AHR is mainly responsible for bone toxicity of dioxin-like compounds and plays a role in bone development. This is likely due to disturbed bone remodeling as indicated by altered serum markers and gene expression. Overall these results indicate that POPs decrease bone strength, but the interpretation is difficult as there is more trabecular bone within cortical bone with compromised quality and increased porosity. / Tiivistelmä
Altistumisen pysyville orgaanisille ympäristökemikaaleille on todettu heikentävän luustoa. Dioksiinien ja dioksiininkaltaisten yhdisteiden vaikutusten on havaittu välittyvän aryylihiilivetyreseptorin (AHR) välityksellä. Huolimatta pitkään kestäneestä tutkimuksesta POP-yhdisteiden sikiönkehityksen aikaisen altistuksen vaikutukset ja etenkin niiden mekanismit ovat edelleen huonosti tunnettuja, samoin kuin AHR:n osuus POP-yhdisteiden luutoksisuudessa ja luuston kehityksessä ylipäätään.
Tässä työssä tutkittiin luuston rakenteellisia ja mekaanisia ominaisuuksia niin perinteisillä kuin uusimmilla biolääketieteen tekniikan menetelmillä. Tutkimuksen tavoitteena on saada uutta tietoa POP-altistuksen ja AHR-aktiivisuuden vaikutuksista luuston kehitykseen ja luukudoksen ikääntymisprosesseihin, mikä edesauttaa kyseisten yhdisteiden riskinarviointia.
Tutkimuksissa altistettiin kantavia rottaemoja 2,3,7,8-tetraklooridibenzo-p-dioksiinille (TCDD), pohjoiselle saasteseokselle ja kaupalliselle Arokloori 1254 PCB-seokselle. Sikiönkehityksen aikana altistuneiden jälkeläisten luuston poikkileikkausen morfologia ja biomekaaniset ominaisuudet mitattiin ja tulokset mallinnettiin vertailuannoksen määrittämiseksi. Lisäksi TCDD-altistettujen rottien luustomatriisin ominaisuuksia selvitettiin nanoindentaatiomenetelmällä. Samaa menetelmää käytettiin myös aikuisiässä TCDD:lle altistettujen villityypin hiirten ja AHR-poistogeenisiten hiirten tutkimiseen. Näiden hiirten luuston hienorakennetta mitattiin myös korkean resoluution mikro-tietokonetomografialla ja niiden luusolujen aktiivisuutta tutkittiin seerumin biomarkkerien ja luun muodostumiseen osallistuvien geenien ekspressiotasojen avulla.
Sikiönkehityksen aikainen altistuminen pohjoiselle saasteseokselle ja Arokloori 1254:lle hidasti luiden pituuskasvua. Lisäksi luiden poikkileikkauspinta-alat olivat pienentyneet ja mekaaniset ominaisuudet heikentyneet. Toisaalta hohkaluun määrä oli lisääntynyt altistumisen seurauksena.
Myös sikiönkehityksen aikainen altistuminen TCDD:lle hidasti luukudoksen kypsymistä ja johti aikuisiällä luukudoksen ennenaikaiseen vanhenemiseen. AHR:llä oli päärooli ainakin aikuisiän vaikutusten ilmenemiselle ja reseptorilla vaikutti olevan rooli luuston kehityksessä ylipäätään. Seerumin biomarkkereiden ja geeniekspression muutosten perusteella nämä vaikutukset johtuvat todennäköisesti luuston uusiutumisen häiriöistä. Yhteenvetona voidaan todeta, että POP-yhdisteet heikentävät luustoa, mutta tämän ilmiön diagnosoiminen on hankalaa, koska huonolaatuisen kuoriluun sisällä hohkaluun määrä on lisääntynyt.
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Optimizing Main Memory Usage in Modern Computing Systems to Improve Overall System PerformanceCampello, Daniel Jose 20 June 2016 (has links)
Operating Systems use fast, CPU-addressable main memory to maintain an application’s temporary data as anonymous data and to cache copies of persistent data stored in slower block-based storage devices. However, the use of this faster memory comes at a high cost. Therefore, several techniques have been implemented to use main memory more efficiently in the literature. In this dissertation we introduce three distinct approaches to improve overall system performance by optimizing main memory usage.
First, DRAM and host-side caching of file system data are used for speeding up virtual machine performance in today’s virtualized data centers. The clustering of VM images that share identical pages, coupled with data deduplication, has the potential to optimize main memory usage, since it provides more opportunity for sharing resources across processes and across different VMs. In our first approach, we study the use of content and semantic similarity metrics and a new algorithm to cluster VM images and place them in hosts where through deduplication we improve main memory usage.
Second, while careful VM placement can improve memory usage by eliminating duplicate data, caches in current systems employ complex machinery to manage the cached data. Writing data to a page not present in the file system page cache causes the operating system to synchronously fetch the page into memory, blocking the writing process. In this thesis, we address this limitation with a new approach to managing page writes involving buffering the written data elsewhere in memory and unblocking the writing process immediately. This buffering allows the system to service file writes faster and with less memory resources.
In our last approach, we investigate the use of emerging byte-addressable persistent memory technology to extend main memory as a less costly alternative to exclusively using expensive DRAM. We motivate and build a tiered memory system wherein persistent memory and DRAM co-exist and provide improved application performance at lower cost and power consumption with the goal of placing the right data in the right memory tier at the right time. The proposed approach seamlessly performs page migration across memory tiers as access patterns change and/or to handle tier memory pressure.
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Arbovirus Persistence and Selection of Persistent Variants Following Chronic Infection in Aedine Mosquitoes: A Comparative Study Between Ae. Aegypti and Ae. Albopictus 30 Days Post Infection With Sindbis VirusLyski, Zoe Leah 01 January 2013 (has links)
In the present investigation two container breeding mosquitoes, Aedes aegypti and Aedes albopictus were exposed to Sindbis virus (SINV). Mosquitoes were proffered a viremic bloodmeal using a vertical membrane feeder in an attempt to infect females while preserving virus-gut interactions that are speculated to be responsible for amplification and selective roles encountered in nature. Cohorts of 50 mosquitoes of each species were exposed to SINV strain TR339 or EMEM in a bloodmeal and incubated in insectary conditions for 30 days. Once infected, the mosquito remains persistently infected for life, accumulating mutations in the virus RNA genome. Plaque size variants may indicate changes to the virus genome, therefore in this investigation TR339 persistent disseminated isolates (TR339-PDIs) were isolated from mosquito legs 30 days post infection (p.i.) and assayed for plaque size differences. These TR339-PDIs represent virus selected for by the whole mosquito. TR339-PDIs following a long term infection were used to study virus adaptations selected for during persistent infection of the mosquito host. The two mosquito species exhibited different host responses to SINV; survivorship, dissemination rates, and immunohistochemistry of mosquito midguts and hindguts were assayed at 30 days p.i. Aedes aegypti and Ae. albopictus along with SINV strain TR339 provide a good model system to study the selective pressures that occur within the whole mosquito. Greater knowledge of the mechanisms of virus persistence in the mosquito host is vital for controlling arthropod-borne disease at the vector level.
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Gènes du métabolisme des xénobiotiques : rôle prédictif dans les niveaux de contamination biologique par les polluants environnementaux et implication dans le risque de cancer du sein. Analyse de l’étude CECILE / Xenobiotic Metabolism Genes : Prediction of Biological Contamination Levels by Environmental Pollutants and Implication in Breast Cancer Risk. Analysis of the CECILE StudyBerrandou, Takiy Eddine 20 December 2018 (has links)
Les gènes du métabolisme des xénobiotiques (MX) impliqués dans l’activation et l’élimination des cancérogènes environnementaux pourraient moduler le risque de cancer du sein, mais leurs effets dans ce cancer ont été peu étudiés et sont mal connus. Les objectifs de la thèse étaient d’étudier le rôle des gènes MX dans le cancer du sein d’une part, et dans les niveaux biologiques de cancérogènes mammaires suspectés, d’autre part. Les analyses ont porté sur les données d’une étude cas-témoins en population sur les cancers du sein (étude CECILE). L’association avec le cancer du sein a été étudiée (1) avec les variants du gène NAT2 qui déterminent le type d’acétyleur lent ou rapide de chaque individu ; (2) les polymorphismes des gènes MX étudiés conjointement au niveau de chacun des gènes et au niveau de l’ensemble du pathway à l’aide d’une méthode exploratoire de type « gene-set ». Dans chacune de ces approches, les interactions avec la consommation de tabac ont été étudiées. Dans une dernière partie, nous avons cherché à identifier les polymorphismes des gènes MX prédictifs des concentrations sanguines de polluants organochlorés persistants (p,p’-DDE et PCB153) chez les témoins de l’étude CECILE. Le risque de cancer du sein était augmenté chez les femmes ayant un profil génétique NAT2 d’acétyleuses rapides par rapport aux femmes ayant un profil d’acétyleuses lentes. Parmi les acétyleuses lentes, les femmes fumeuses avaient un risque de cancer du sein augmenté par rapport aux non fumeuses indiquant l’existence d’une interaction tabac-NAT2. L’approche « gene-set » montrait que les polymorphismes au niveau de plusieurs gènes MX et au niveau de l’ensemble du pathway étaient associés collectivement au cancer du sein. L’association entre le cancer du sein et l’ensemble des polymorphismes du pathway XM était observée chez les fumeuses, indiquant le rôle de la consommation de tabac dans cette association. Enfin, nous avons montré l’effet du gène CYP2B6 en tant que déterminant des niveaux sanguins de p,p’-DDE et PCB153. Nos résultats mettent en évidence un rôle des gènes XM dans le cancer du sein qui peut être expliqué par leur fonction dans le métabolisme et l’élimination des cancérogènes environnementaux. / The xenobiotic metabolism (XM) genes involved in the activation and elimination of environmental carcinogens may modulate breast cancer risk, but their effects in breast cancer have been little studied and are poorly understood. The objectives of the PhD were to study the role of XM genes in breast cancer on the one hand, and in the biological levels of suspected breast carcinogens on the other. The analyses were based on a population-based case-control study on breast cancer (CECILE study). We investigated the association of breast cancer (1) with NAT2 gene variants that determine the type of slow or rapid acetylator in each individual; (2) with polymorphisms of XM genes that were studied jointly at the gene and at the XM pathway level using a gene set method. In each of these approaches, interactions with tobacco consumption were studied. In a final section, we sought to identify polymorphisms of XM genes that predict blood concentrations of persistent organochlorine pollutants (p,p'-DDE and PCB153) among the controls of the CECILE study.The risk of breast cancer was increased in women with a NAT2 genetic profile of rapid acetylators compared to women with a profile of slow acetylators. Among slow acetylators, current smokers had an increased risk of breast cancer compared to non-smokers, indicating an interaction between tobacco smoking and NAT2 genotype. The gene set approach showed that polymorphisms at the level of some XM genes and at the level of the entire pathway were collectively associated with breast cancer. The association between breast cancer and all pathway XM polymorphisms was observed in female smokers, indicating a role for tobacco smoking in this association. Finally, we have shown that CYP2B6 gene was a determinant of blood levels of p,p'-DDE and PCB153. Our results highlight a role of XM genes in breast cancer that is explained by their function in the metabolism and elimination of environmental carcinogens.
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