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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Reliability modeling for capital project decisions

Poulassichidis, Antonios 05 January 2011 (has links)
Exploration and Production (E&P) project costs within the oil industry are continuously increasing reflecting a reality of more harsh environments, remote locations with minimal existing infrastructure and cost increases for materials and skilled resources. The significant capital expenditures translate to a number of projects either for new or revamped production facilities. Successful project completion requires a series of correct decisions throughout the project life-cycle namely design, construction, operations, maintenance and decommissioning. Using a Reliability, Availability and Maintainability (RAM) model as part of the project decision process is an E&P industry best practice that recently gained acceptance in Hess Corporation. This paper presents the RAM methodology and the gains from its application in a capital project. / text
82

THE INTERACTION BETWEEN THE INTRACLUSTER MEDIUM AND THE CLUSTER STELLAR CONTENT

Sivanandam, Suresh January 2010 (has links)
We study specific aspects of the relationship between the stellar content and the intracluster media (ICM) of galaxy clusters. First, we attempt to solve the long-standing difficulty in explaining the highly enriched ICM by including a previously unaccounted for stellar component: the intracluster stars. To determine the relative contributions of galactic and intracluster stars to the enrichment of the intracluster medium (ICM), we present X-ray surface brightness, temperature, and Fe abundance profiles for a set of twelve galaxy clusters for which we have extensive optical photometry. Assuming a standard IMF and simple chemical evolution model scaled to match the present-day cluster early-type SN Ia rate, the stars in the brightest cluster galaxy (BCG) plus the intracluster stars (ICS) generate 31⁺¹¹₋₉%, on average, of the observed ICM Fe within r₅₀₀(∼ 0.6 times r₂₀₀, the virial radius). Because the ICS typically contribute 80% of the BCG+ICS Fe, we conclude that the ICS are significant, yet often neglected, contributors to the ICM Fe within r₅₀₀. However, the BCG+ICS fall short of producing all the Fe, so metal loss from stars in other cluster galaxies must also contribute. By combining the enrichment from intracluster and galactic stars, we can account for all the observed Fe. These models require a galactic metal loss fraction (0.84(−0.14)^(+0.11)) that, while large, is consistent with theoretical models of Fe mass not retained by galactic stars. The SN Ia rates, especially as a function of galaxy environment and redshift, remain a significant source of uncertainty in further constraining the metal loss fraction. Second, we study the effects of ram-pressure stripping on infalling galaxies using a warm molecular hydrogen (H₂) as a tracer by carrying out a Spitzer infrared spectrograph (IRS) survey of four galaxies with signatures of ram-pressure stripping. We have discovered two galaxies, ESO 137-001 and NGC 4522, with warm H₂ tails stretching 20 kpc and 4 kpc in length, respectively. In the case of ESO 137-001 where we measure a warm H₂ mass loss rate of ∼ 2 − 3 M⊙ yr⁻¹, we estimate that the galaxy will lose all of its gas in a single pass through the cluster core. Strong warm H₂ emission is detected in one other galaxy, CGCG 97-073, which a region within its tail that is mainly dominated by H₂ emission. The warm H₂ observed in these three galaxies share similar temperature and column density properties with warm H₂ masses ranging from 10⁶ − 10⁸ M⊙. From a comparison with the SINGS warm H₂ sample, our results indicate that these galaxies experiencing significant ram-pressure stripping show anomalously high warm H₂ emission that cannot be explained purely from star formation. This adds credence to the hypothesis that H₂ within these galaxies is being shock-heated from the interaction with the ICM. We also discover that stripping of warm and hot dust, as measured at 8 μm and 24 μm, is a common feature of the galaxies observed in our sample. In the case of NGC 4522, we capture the turbulent nature of the stripping process. We measure the star formation rates using published Hα and measured 24 μm luminosities for all of our galaxies and find that some of them have suppressed star formation rates compared to similar mass counterparts in the field. We find a possible association between Hα and warm H₂ emission in three of the four galaxies observed. We conclude that the variation of H₂ properties observed in our sample is likely due to the galaxies being in different stages of ram-pressure stripping. Finally, we report on our efforts to improve the performance of the Lochkeed Arizona Infrared Spectrometer (LAIRS), a near-IR, tunable filter imager. We have made significant progress in identifying the sources of key issues such as the a highly asymmetric line profile and the unstable performance of the servo controller at the MMT. Solutions have been implemented for these issues, such as a revised mounting strategy for the tunable filter plates and a completely new controller with higher bandwidth. Significant progress has been made towards resolving these issues, but a few issues remain before LAIRS meets all of its requirements.
83

Spädbarnsanalys : När samspelet mor - barn inte fungerar

Hübner, Ulrika January 2010 (has links)
The aim of the study is to investigate the practice of psychoanalysis with infants, and its effect on mother and child. With psychoanalytical thoeries and contemporary research on infants interaction as a basis, five interwievs with psychoanalysts in practice has been done. Also taking part of a clinical meeting with nine psychoanalysts has been done. Two of the interwieved analysts where part of this meeting, therefor the total sum of twelve psychoanalysts who reports their thoughts about the process i infantanalysis. The study also includes three participating observations of infantanalysis. The collected material has been examined with the intention to understand the psychoanalysts own experiences as well as the eventual effect the analys could have on mother, child and sometimes the father. The psychoanalysts describes how the treatment really helps both mother an child, and the proof for this is the mothers way to change her way to interact with the baby. The result shows the analysts themselves believes the interaction mother – child is improving with help from analysis. The discussion debate however the eventual effect on mother – child can be established, how the analysis is practised and if the psychoanalysts way to treat children is anything anyone could practise. / Syftet med denna studie är att undersöka psykoanalys med spädbarn och dess inverkan på mor-barn samspelet. Med utgångspunkt i psykoanalytiska teorier och nutida forskning om spädbarnets medfödda samspelskompetenser har fem intervjuer med praktiserande psykoanalytiker utförts. Utöver dessa fem intervjuer har medverkande på ett kliniskt möte med nio närvarande psykoanalytiker gjorts. Två av de intervjuade ingår i gruppen psykoanalytiker på det kliniska mötet; totalt redogörs tolv psykoanalytikers uppfattningar om processerna i spädbarnsanalys. I undersökningen ingår också tre deltagande observationer av spädbarnsanalys. Det insamlade materialet har granskats med intentionen att förstå både psykoanalytikernas egna upplevelser av spädbarnsanalysen, och den eventuella effekt analysen har på mor, barn och i vissa fall även fadern. Spädbarnsanalytikerna beskriver att behandlingen hjälper både mor och barn och beviset för det är att moderns beteende och förmåga att uttrycka sig förändras så att samspelet mor-barn fungerar bättre. Resultatet visar att spädbarnsanalytikerna själva anser sig se att samspelet mellan mor och barn stärks av analys. Diskussionen tar upp hur den eventuella effekten på mor - barn i analys kan påvisas, hur analysen praktiseras och om psykoanalytikerns sätt att bemöta spädbarn kan användas av alla som möter mor - barn par där samspelet inte fungerar.
84

Space-Efficient Data Structures in the Word-RAM and Bitprobe Models

Nicholson, Patrick 06 August 2013 (has links)
This thesis studies data structures in the word-RAM and bitprobe models, with an emphasis on space efficiency. In the word-RAM model of computation the space cost of a data structure is measured in terms of the number of w-bit words stored in memory, and the cost of answering a query is measured in terms of the number of read, write, and arithmetic operations that must be performed. In the bitprobe model, like the word-RAM model, the space cost is measured in terms of the number of bits stored in memory, but the query cost is measured solely in terms of the number of bit accesses, or probes, that are performed. First, we examine the problem of succinctly representing a partially ordered set, or poset, in the word-RAM model with word size Theta(lg n) bits. A succinct representation of a combinatorial object is one that occupies space matching the information theoretic lower bound to within lower order terms. We show how to represent a poset on n vertices using a data structure that occupies n^2/4 + o(n^2) bits, and can answer precedence (i.e., less-than) queries in constant time. Since the transitive closure of a directed acyclic graph is a poset, this implies that we can support reachability queries on an arbitrary directed graph in the same space bound. As far as we are aware, this is the first representation of an arbitrary directed graph that supports reachability queries in constant time, and stores less than n choose 2 bits. We also consider several additional query operations. Second, we examine the problem of supporting range queries on strings of n characters (or, equivalently, arrays of n elements) in the word-RAM model with word size Theta(lg n) bits. We focus on the specific problem of answering range majority queries: i.e., given a range, report the character that is the majority among those in the range, if one exists. We show that these queries can be supported in constant time using a linear space (in words) data structure. We generalize this result in several directions, considering various frequency thresholds, geometric variants of the problem, and dynamism. These results are in stark contrast to recent work on the similar range mode problem, in which the query operation asks for the mode (i.e., most frequent) character in a given range. The current best data structures for the range mode problem take soft-Oh(n^(1/2)) time per query for linear space data structures. Third, we examine the deterministic membership (or dictionary) problem in the bitprobe model. This problem asks us to store a set of n elements drawn from a universe [1,u] such that membership queries can be always answered in t bit probes. We present several new fully explicit results for this problem, in particular for the case when n = 2, answering an open problem posed by Radhakrishnan, Shah, and Shannigrahi [ESA 2010]. We also present a general strategy for the membership problem that can be used to solve many related fundamental problems, such as rank, counting, and emptiness queries. Finally, we conclude with a list of open problems and avenues for future work.
85

AN EFFECTIVE CACHE FOR THE ANYWHERE PIXEL ROUTER

Raghunathan, Vijai 01 January 2007 (has links)
Designing hardware to output pixels for light field displays or multi-projector systems is challenging owing to the memory bandwidth and speed of the application. A new technique of hardware that implements ‗anywhere pixel routing‘ was designed earlier at the University of Kentucky. This technique uses hardware to route pixels from input to output based upon a Look up Table (LUT). The initial design suffered from high memory latency due to random accesses to the DDR SDRAM input buffer. This thesis presents a cache design that alleviates the memory latency issue by reducing the number of random SDRAM accesses. The cache is implemented in the block RAM of a field programmable gate array (FPGA). A number of simulations are conducted to find an efficient cache. It is found that the cache takes only a few kilobits, about 7% of the block RAM and on an average speeds up the memory accesses by 20-30%.
86

Adaptive Range Counting and Other Frequency-Based Range Query Problems

Wilkinson, Bryan T. January 2012 (has links)
We consider variations of range searching in which, given a query range, our goal is to compute some function based on frequencies of points that lie in the range. The most basic such computation involves counting the number of points in a query range. Data structures that compute this function solve the well-studied range counting problem. We consider adaptive and approximate data structures for the 2-D orthogonal range counting problem under the w-bit word RAM model. The query time of an adaptive range counting data structure is sensitive to k, the number of points being counted. We give an adaptive data structure that requires O(n loglog n) space and O(loglog n + log_w k) query time. Non-adaptive data structures on the other hand require Ω(log_w n) query time (Pătraşcu, 2007). Our specific bounds are interesting for two reasons. First, when k=O(1), our bounds match the state of the art for the 2-D orthogonal range emptiness problem (Chan et al., 2011). Second, when k=Θ(n), our data structure is tight to the aforementioned Ω(log_w n) query time lower bound. We also give approximate data structures for 2-D orthogonal range counting whose bounds match the state of the art for the 2-D orthogonal range emptiness problem. Our first data structure requires O(n loglog n) space and O(loglog n) query time. Our second data structure requires O(n) space and O(log^ε n) query time for any fixed constant ε>0. These data structures compute an approximation k' such that (1-δ)k≤k'≤(1+δ)k for any fixed constant δ>0. The range selection query problem in an array involves finding the kth lowest element in a given subarray. Range selection in an array is very closely related to 3-sided 2-D orthogonal range counting. An extension of our technique for 3-sided 2-D range counting yields an efficient solution to adaptive range selection in an array. In particular, we present an adaptive data structure that requires O(n) space and O(log_w k) query time, exactly matching a recent lower bound (Jørgensen and Larsen, 2011). We next consider a variety of frequency-based range query problems in arrays. We give efficient data structures for the range mode and least frequent element query problems and also exhibit the hardness of these problems by reducing Boolean matrix multiplication to the construction and use of a range mode or least frequent element data structure. We also give data structures for the range α-majority and α-minority query problems. An α-majority is an element whose frequency in a subarray is greater than an α fraction of the size of the subarray; any other element is an α-minority. Surprisingly, geometric insights prove to be useful even in the design of our 1-D range α-majority and α-minority data structures.
87

La variabilité dans l'intensité ou l'orientation des interactions sexuelles chez le bélier : Etude des structures centrales impliquées / Variability in the intensity of direction of sexual interactions in the ram : a study of central structures involved

Santos, Fernando Carlos Borja Dos 14 December 2011 (has links)
L’objectif principal de cette thèse est de comprendre l’origine de la variabilité d’expression du comportement sexuel (CS). Nous avons trouvé que l’approche latérale est le CS le plus exprimé et que sa quantification peut servir comme mesure de la libido et donner une idée de la performance. Nous avons montré des effets remarquables de l’âge et de la lumière sur le CS du bélier. Nous avons également montré que les structures cérébrales impliquées dans la phase motivationnelle et consommatoire ne étaient pas les mêmes et que quel que soit le partenaire sexuel préféré, l’exposition à ce partenaire provoquait une activation des mêmes structures cérébrales ; le niveau de libido semble être déterminé par des sites spécifiques et bien précis comme l’aire préoptique, le noyau paraventriculaire et la partie médiane du Lit de la strie terminale. Le Cortex ent pourrait fonctionner comme un inhibiteur de la motivation hétérosexuelle. / The main objective of this thesis was to acquire a better understanding of the origin of the variability of the expression of sexual behavior. The nudging is most expressed sexual behavior and quantification of this behavior can be used to measure their libido and give a clue on their performance. We have discovered the remarkable effects of age et lighting of the ram's sexual behavior and that the cerebral structures involved in the motivation phase and consummatory phase are not the same and seems that, no matter which sexual partner is chosen, the fact of being exposed to this partner provokes the activation of these cerebral structures et what the expression of sexual motivation level seems to have specific and precise sites in the Preoptic Area, the Paraventricular Nucleus (PVN) and the Nucleus of the bed of the striae terminalis medial (BNSTmed). The Entorhinal cortex could function as an inhibitor of heterosexual motivation.
88

Kontamination av RAM-minne vid användning av IT-forensisk mjukvara

Franzén, Joel, Norryd, Johan January 2018 (has links)
This report addresses a very specific area of computer forensics and information security. A computer forensic scientict are needed to act in critical situations, therefore the person needs broad knowledge of the physical memory, also known as volatile memory withincomputer forensics. As cybercrimes are rapidly increasing more for each year, it has also contributed to a huge development in the computer forensic department. Since the volatile memory of a computer plays a significant role in an investigation, a computer forensics actions can be crucial in the collection of evidence. Volatile memory is something that exists in all computer systems and the purpose is to store information temporarily, in other words, it only exists when the system is active. Volatile memory is an information source that is rich in information from a computer forensic perspective. Volatile memories are built up of binary code, which requires that these are analyzed using various tools. This availability of these tools today is very large. There are several different methods for analyzing the volatile memory in a computer, not just for the government, but also for the public. As the range of these methods and tools are big, we have chosen to focus on computer forensic tools that pay an important part of the work of a computer forensic. The execution of the practical part, we have chosen to apply in a virtualization environment, to carry out the experiments in a controlled manner. The experiments were a big success in showing that changes to the memory allocation have occurred in the event of contamination. When the dump-files were performed by the tools, a percentage difference could be determined and further analysis of these showed that contamination occurred. / Denna rapport behandlar ett väldigt specifikt område inom IT-forensik och informationssäkerhet. Då berörda parter, det vill säga IT-forensiker, emellanåt behöver agera i kritiska lägen krävs det att personen har breda kunskaper om det volatila minnet, mer känt som volatila minnen inom IT-forensik. Då IT-brott ökar allt mer för varje år behöver också utvecklingen inom IT-forensik ständig utveckling. Eftersom det volatila minnet ien dator har en betydande roll i samband med en utredning kan en IT-forensikers handlingar vara avgörande i bevisinsamlingen. Volatila minnen är något som finns i alla datorsystem och dess syfte är att lagra information temporärt, då minnet endast existerar när systemet är igång. Det volatila minnet är en informationskälla som är rik på viktig information ur ett IT-forensiskt perspektiv. Volatila minnen är uppbyggda av binärkod, vilket kräver att dessa analyseras med hjälp av olika verktyg. Utbudet av dessa verktyg är idag väldigt stora, det finns flertalet olika metoder för att gå tillväga för att analysera det volatila minnet i en dator, inte bara för myndigheter, utan även för allmänheten. Eftersom utbudet av dessa metoder och verktyg är stora, har vi valt att inrikta oss på IT-forensiska verktyg som är en viktig del i arbetet som IT-forensiker. Utförandet av den praktiska delen har vi valt att applicera i virtualiseringsmiljö, för att på ett kontrollerat sätt utföra experimenten. Vid experimenten erhöllsdet framgångsrika resultat där påvisning av att förändringar i minnesallokeringar skett, det vill säga kontamination. När RAM-dumparna väl hade utförts av verktygen fastställdes en procentuell skillnad och vidare analysering av dessa påvisade att kontamination förekommit.
89

Uso do semên ovino congelado em inseminação artificiais cervicais e fatores que afetam a fertilidade dos rebanhos / Employment of ram frozen semen in cervical superficial inseminations and factors affecting flock fertility

Pinheiro, Carlos Bayard Martins January 2009 (has links)
O melhoramento genético ovino carece de uma maior conexão genética entre os rebanhos, o que pode solucionado pelo uso mais intensivo do sêmen congelado. Entretanto, com os níveis tecnológicos atualmente disponíveis o sêmen congelado apenas pode ser empregado com eficácia diretamente no útero, dependendo de sincronização de estros e mão de obra especializada para as inseminações via laparoscopia. Uma outra alternativa é o uso de sêmen congelado com 200 milhões de espermatozóides por dose com inseminações efetuadas cerca de doze horas após a identificação do estro, preconizado para a inseminação artificial dos ovinos na Noruega pelos próprios produtores. O presente ensaio consta de uma adaptação local deste modelo com o objetivo geral de verificar a viabilidade de uso da inseminação cervical superficial com sêmen ovino congelado numa dose de 0,25 ml contendo 200 x 106 de espermatozóides em palhetas de 0,50 ml após cio natural, empregando baixo uso de insumos e mão de obra semi-qualificada. As observações foram procedidas em duas propriedades no Rio Grande do Sul, incluindo 1419 ovelhas das raças Merino, Ideal e Texel. Os resultados obtidos indicaram que as diferenças nas taxas de não retorno entre carneiros poderá ser minimizada através da utilização de outros métodos de análise e seleção de carneiros mais férteis após os procedimentos de congelamento/descongelamento, e, adicionalmente que a constatação de uma taxa de não retorno entre 25-35% nas distintas condições investigadas, permitem inferir que os sistemas investigados podem ser utilizados para interligar geneticamente rebanhos via uso de sêmen congelado. / A sheep improvement program depends on genetic connexion among flocks, which could be done by extensive use of frozen semen. However, nowadays-available technology just recommends the employment of frozen semen directly inside the uterine ambient through laparoscopy. Alternatively, there is a model recommended for Norway producers including frozen semen with 200 millions of sperms used in cervical superficial inseminations up to twelve hours from oestrus detection. The present essay is an local adaption of this system aiming to verify the viability of the employment of frozen semen for sheep reproduction in a volume of 0,25 ml, with 200 x 106 sperms in 0,50 ml straws, after natural oestrus, using low input resource and semi-qualified artificial insemination technicians. The observations were done in the two properties located at Rio Grande do Sul, including 1419 ewes from Merino, Ideal and Texel breeds. The results obtained indicate that the differences in non return rates among rams could be minimized by the employment of other methods of ram selection before the freezing procedures, and additionally the observed 25-35% non return rates in the distinct conditions investigated, permits to infer that the tested system could be useful to connect genetically the flocks using frozen semen.
90

Avaliação de duas curvas de congelação e dois sistemas de refrigeração para a preservação de sêmen ovino combinados com três diluentes comerciais e suas interferências na motilidade viabilidade, potencial de membrana mitocondrial e defeitos acrossomais espermáticos / Evaluation of three semen commercial extenders after two different freezing curves and during two different liquid storage on ram sperm motility, viability, mitochondrial membrane potential and defected acrosome

Baggio, Melchiani January 2012 (has links)
Com os processos de preservação do sêmen, os espermatozoides sofrem danos devido à indução de alterações estruturais e funcionais na membrana e, aliada a estrutura anatômica do cérvix da ovelha, repercute na redução de fertilidade após a inseminação artificial. Muitos protocolos de congelação e de refrigeração aliados a inúmeros diluentes, vêm sendo estudados, a fim de diminuir os danos causados a essas células e aumentar sua capacidade fertilizante. Para otimizar os processos de congelação e de refrigeração, os objetivos deste estudo foram determinar (1) a influência do método de congelação na motilidade, viabilidade, potencial de membrana mitocondrial e nos defeitos acrossomais do semen ovino criopreservado e (2) a influência de três diluentes comerciais na motilidade, viabilidade, potencial de membrana mitocondrial e nos defeitos acrossomais do sêmen ovino refrigerado. Doze ejaculados foram coletados, diluídos e congelados utilizando (A) uma curva manual de congelação (em vapor de nitrogênio liquido) e (B) um congelador programável (CL-8800, Cryologic Freeze Control®). Na curva A, as amostras foram refrigeradas e congeladas à 30°C/min. Na curva B, houve uma redução de temperatura de 20°C até -50°C durante 37min. Imediatamente após as curvas de criopreservação, as amostras foram submersas em nitrogênio líquido (-196ºC). Para o descongelamento, as palhetas foram submetidas à 37°C por 20seg e analisadas. Para os protocolos de refrigeração, o sêmen diluído em Botubov®, Bovimix® e TYB® foi armazenado à 5°C e à 15°C, e avaliado em 0, 24, 48 e 72h pós coleta. As análises de viabilidade e potencial de membrana mitocondrial (MMP) foram realizadas por citometria de fluxo, e a motilidade e os defeitos acrossomais foram avaliados microscopicamente. Motilidade (29%), viabilidade (18%) e MMP (26%) dos espermatozoides criopreservados com o diluente Bovimix® e a curva B foram significativamente (P<0,05) superiores do que todos os outros tratamentos. As amostras refrigeradas e diluídas com o diluente Bovimix® apresentaram resultados superiores, tanto à 5°C quanto à 15°C, para MMP (44% e 51%, respectivamente) e viabilidade (60% e 53%, respectivamente) 72h pós coleta, quando comparado com as amostras diluídas com Botubov® e TYB®. Em conclusão, os protocolos de congelação/descongelação e de refrigeração utilizados nestes experimentos, reduziram a motilidade, viabilidade, MMP e aumentaram os defeitos acrossomais quando comparados com o sêmen fresco. Os protocolos de congelação/descongelação prejudicaram mais a função espermática quando comparado com os protocolos de refrigeração. Por fim, os resultados sugerem que as amostras espermáticas diluídas com o diluente Bovimix® causou menos danos às células espermáticas do que as amostras diluídas com os diluentes Botubov® e TYB®, tanto nos protocolos de congelação, quanto nos protocolos de refrigeração. / The process of sperm preservation damages spermatozoa due to induction of structural and functional changes in the membrane, and allied to the ewe cervix anatomy, reflects the reduction in fertility after artificial insemination. Many semen preservation protocols including freezing and cooling rates coupled with different extenders have been studied in order to reduce sperm cryo-damage, increase the fertilizing capacity and increase the time of storage. To improve freezing and cooling processes, the objectives of this study were to determine (1) the influence of freezing method on sperm motility, viability, mitochondrial membrane potential and defected acrosome of cryopreserved sperm and (2) the influence of three commercial extenders on the motility, viability, mitochondrial membrane potential and defected acrosome of liquid storaged and frozen-thawed sperm. Twelve semen samples were collected from two mature rams, pooled, and diluted in Botubov®, Bovimix® and TYB®, and frozen using (A) a manual freezing method (liquid nitrogen vapor) and (B) an automated programmable freezer (CL-8800, Cryologic Freeze Control®). For curve A, semen samples were maintained at 37°C and then cooled/frozen at 30°C/min. For curve B, the temperature reduced from 20°C to -50°C during 37min. Immediately, after cryopreservation curves, samples were plunged and stored into liquid nitrogen (-196ºC). Then, the straws were thawed at 37°C for 20sec, and analyzed. For cooling studies, pooled ram semen was diluted in Botubov®, Bovimix® and TYB®, stored at 5°C and at 15°C, and evaluated at 0, 24, 48 and 72 h post collection. For viability and mitochondrial membrane potential (MMP) assessments, semen samples were stained and analyzed by flow cytometry. Motility and defected acrosome assessments were analyzed microscopically. Motility (29%), viability (18%) and MMP (26%) of spermatozoa cryopreserved in Bovimix® coupled to curve B were significantly (P<0.05) higher than all other treated groups. Semen samples diluted with Bovimix® and stored at 5°C and at 15°C yielded better MMP (44% and 51%, respectively) than the samples diluted in Botubov® and in TYB®, and also showed higher viability characteristics at 5°C and at 15°C (60% and 53%, respectively) 72h post collection. In conclusion, freezing/thawing and cooling protocols used in these experiments reduced sperm motility, viability, MMP and increased the defects of acrosomes when compared to fresh semen. Freezing/thawing protocols harmed more spermatozoa function than cooling protocols. Furthermore, our results suggest that the semen samples diluted in the extender Bovimix® caused the least cellular injury than the samples diluted in Botubov® and in TYB® on freezing and on cooling protocols.

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