• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 44
  • 29
  • 2
  • 1
  • 1
  • Tagged with
  • 102
  • 22
  • 21
  • 15
  • 14
  • 14
  • 12
  • 11
  • 11
  • 10
  • 9
  • 9
  • 9
  • 9
  • 9
  • 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.
91

A study of factors which contribute to appropriate pregnancy care for Aboriginal women in far north Queensland

Humphrey, Michael David Unknown Date (has links)
No description available.
92

A study of factors which contribute to appropriate pregnancy care for Aboriginal women in far north Queensland

Humphrey, Michael David Unknown Date (has links)
No description available.
93

Psychological well-being, maternal-foetal bonding and experiences of Indian surrogates

Lamba, Nishtha January 2018 (has links)
Over the past two decades, India has become an international hub of cross-border surrogacy. The extreme economic and cultural differences between international couples seeking surrogacy and the surrogates themselves, clinics compromising health of surrogates for profit, the stigmatisation of surrogacy in India, and the constant surveillance of these women living in a ‘surrogate house’, have raised concerns regarding the potentially negative psychological impact of surrogacy on Indian surrogates. The primary aims of the thesis were (i) to conduct a longitudinal assessment of surrogates’ psychological problems (anxiety, depression and stress) from pregnancy until several months after relinquishing the baby to the intended parents, (ii) to examine the nature of the bond formed between surrogates and the unborn baby and establish whether this prenatal bond contributes to their psychological problems, and (iii) to explore the experiences of surrogates during and post-surrogacy. Fifty surrogates were compared with a matched group of 69 expectant mothers during pregnancy. Of these, 45 surrogates and 49 compairson group of mothers were followed up 4-6 months after the birth. All surrogates were hosting pregnancies for international intended parents and had at least one child of their own. Data were obtained using standardised questionnaires and in-depth interviews and were analysed using quantitative and qualitative methods. Indian surrogates were found to be more depressed than the comparison group of mothers, both during pregnancy and after the birth. However, giving up the newborn did not appear to add to surrogates’ levels of depression. There were no differences between the surrogates and the expectant mothers in anxiety or stress during either phase of the study. The examination of risk factors for psychological problems among the surrogates showed that anticipation of stigma, experiences of social humiliation and receiving insufficient support during pregnancy were associated with higher levels of depression following the birth. With respect to bonding with the unborn child, surrogates experienced lower levels of emotional bonding (e.g. they interacted less, and wondered less about, the foetus), but exhibited higher levels of instrumental bonding (e.g. they adopted better eating habits and avoided unhealthy practices during pregnancy), than women who were carrying their own babies. Contrary to concerns, greater bonding with the unborn child was not associated with increased psychological problems post-relinquishment. All surrogates were able to give up the child. Meeting the intended parents after the birth positively contributed towards surrogates’ satisfaction with relinquishment whereas meeting the baby did not. The qualitative findings on surrogates’ experiences showed that the majority lacked basic medical information regarding surrogacy pregnancy; hid surrogacy from most people; felt positive and supported at the surrogate house; lived in uncertainty regarding whether or not they would be allowed to meet the intended parents and the baby; and did not actually get to meet them. These findings have important implications for policy and practice on surrogacy in the Global South.
94

The efficiency of ultrasonorgraphy in monitoring ovarian structures and foetal development in goats, sheep and cattle as verified through laparoscopy and laparotomy

Siphugu, Steven Mbonalo 18 May 2018 (has links)
MSCAGR (Animal Science) / Department of Animal Science / The main purpose of this study was to assess the efficiency of ultrasonography in monitoring reproductive organs, pregnancy diagnosis, and foetal gender identification and to verify its reliability by laparoscopy and laparotomy, where applicable. Reproductive organs, pregnancy diagnosis and gender of the foetus were examined by A-mode ultrasound using 3.0 - 8.0 MHz trans-rectal transducer. A Sony Olympus Model laparoscope with a camera transducer was used to monitor the reproductive organs and pregnancy diagnosis. In monitoring the follicular dynamics, daily ultrasonography (ULTS) scanning was done for 17 days in sheep and for 21 days in both goats and cattle. Follicles of diameter ≥ 3 mm were selected for analysis of growth, ovulation and regression. For determining the efficiency of the techniques, laparoscopy (LAPSC) and laparotomy (LAPT) were used on days 3 and 10 of the goats and sheep oestrous cycle. The follicles were grouped into three categories according to their diameter as 3 - 4.9 mm, 5 - 7.9 mm and ≥ 8 mm, whereas the follicles of cattle were grouped as 3 - 4.9 mm, 5 - 9.9 mm and ≥ 10 mm. Early pregnancy diagnosis examinations were carried out from day 18 post insemination until pregnancy was confirmed. Foetal gender examinations were conducted from day 40 of pregnancy until the day the gender of the foetus was confirmed. Follicular development was accompanied by the occurrence of waves of follicular growth at different period of the oestrous cycle. The first follicular wave emerged on day 1.0 ± 0.4 in goats, 1.2 ± 0.4 in sheep and 2.2 ± 0.4 in cattle. The maximum diameter of the dominant follicles of observed follicular waves in goats was 7.3 ± 0.4 mm, 6.6 ± 0.2 mm, 7.3 ± 0.2 mm; in sheep was 6.4 ± 0.4 mm, 6.6 ± 0.4 mm and 6.7 ± 0.7 mm and in cattle was 13.1 ± 0.8 mm, 14.2 ± 0.6 mm and 15.7 ± 0.6 mm in wave 1, 2 and 3, respectively. However, the maximum size of the dominant follicle of the ovulatory wave in cattle was larger than the dominant follicles of both first and second waves, but in goats and sheep the dominant follicles were of similar size throughout the waves. In cattle, the ovulatory wave was shorter (p ˂ 0.05) than the duration of the first and second waves, while in sheep and goats were similar throughout the waves. In goats the total number of follicles counted in right and left ovaries under category 3 - 4.9 mm was lower with ULTS and LAPSC than with LAPT method (p ˂ 0.05). In sheep the mean number of follicles between 3 - 4.9 mm category in both right and left ovaries were different (p ˂ 0.05) between ULTS and LAPT. However, for categories 5 - 7.9 mm and ≥ 8 mm in both goats and sheep the mean numbers of follicles observed by all techniques were similar (p ˃ 0.05). In goats, pregnancy diagnosis accuracy improved from zero percent on day 18 to 100% on day 26 - 28, in sheep pregnancy diagnosis was 40% on day 18 and improved to 100% on day 20 - 22 vi of gestation. In cattle accuracy of pregnancy diagnosis was not possible at day 18 and gradually increased to 100% on day 30 - 32 of gestation. Out of 5 (100%) goat’s foetuses whose gender was determined, the diagnosis was correct in 100% (3/3) of the male foetuses and 100% (2/2) of the female foetuses. In sheep two foetuses were sexed as males while the other three were sexed as females and were both 100%. Out of 60% (3/5) of foetuses examined in cattle, 1 (100%) was identified as male and the remaining 2 (100%) were identified as females. The results obtained confirmed that the accuracy for foetal gender by ultrasonography was 100% in all foetuses observed. The current study demonstrated that trans-rectal ultrasonography examination is an efficient method for monitoring follicular dynamics, diagnosing pregnancy and foetal gender identification and that it is as reliable as laparoscopy and laparotomy where they were applied together. / NRF
95

The right sized cow for emerging and commercial beef farmers in semi-arid South Africa : connecting biological and economic effeciency

Venter, Theo Muller January 2018 (has links)
Text in English / Cow size influences biological efficiency of individual animals, which influences herd composition and stock flow. This in turn influences the economic efficiency of the herd. This research followed the thread from animal size, to biological efficiency, to economic efficiency for beef cattle production under a typical production system in semi-arid South Africa. Cattle were grouped into three groups namely small, medium and large cattle, with mature weights of 300kg, 450kg and 600kg respectively. The net energy requirements of individual cattle were calculated for maintenance, growth, lactation and foetal production, for each of the three sizes. Growth rates, milk yield, reproduction rates, and management practices were assumed from existing research. Next the stock flow for a herd of small, medium and large cattle were calculated from the above. Income and expenses as commonly used in the research area were calculated from the stock flow. Gross profit above allocated costs were subsequently calculated for the three herds under the above-mentioned conditions. When assuming similar reproduction and growth rates for small, medium and large mature cattle, the following results were obtained: more heads of small cattle could be held on a set resource base, but the total live weight of a herd of large cattle that could be held on the same resource base was greater. This was mostly due to proportionately lower maintenance energy requirements in the herd of large cattle. In the simulation in this study, maintenance energy requirements for the herd of large cattle was 71.2%, compared to 72.0% for the herd of medium cattle and 73.1% for the herd of small cattle. Income from the herd of small cattle was the lowest, as less kilograms of beef were available to sell. Allocated costs for the herd of small cattle were the highest, due to a large number of expenses being charged per head of cattle. As a result, the herd of large cattle were more economically efficient than their smaller counterparts. Income above allocated costs for the herds of large, medium and small cattle were R1,182,865, R1,085,116 and R946,012 respectively. Larger cattle generally have a lower reproduction rate under similar conditions. No equation exists that directly links size to reproduction rates, especially considering the vast number of variables that influences reproduction rates. However, in the form of scenarios, it could be calculated that, given a reproduction rate of 80% for mature small cattle, when reproduction rates of large cattle were 24.7% lower than that of small cattle and the reproduction rates of medium cattle were 15.4% lower than that of small cattle, the large and medium herds became less profitable than the small herd. Smaller cattle mature faster than larger cattle which provides the opportunity for early breeding. When small cattle were bred early, at 15 months, at a calving rate of only 44.5% it was more profitable than when the same cows were bred at 24 months. When medium cattle were bred at 15 months, a calving rate of 37.0% was needed to be more profitable than when they were bred at 24 months. Even when the herd of small cattle were bred at 15 months with a reproduction rate of 100%, it could still not match the profitability of the herd of large cattle bred at 24 months given the reproduction rates of all other classes of animals were similar. When the herd of medium cattle were bred at 15 months, at a calving rate of 53.7%, it matched the profit of the herd of large cattle that were bred at 24 months, when the reproduction rates of other classes were equal. Scenarios were considered were feed intake was limited. When feed was limited to a specific amount, smaller cattle were more biologically efficient and cattle with potential for small mature sizes would grow to a larger size than cattle with potential for medium and large mature sizes. When feed was limited by a factor of the calculated energy requirements of small, medium and large cattle, large cattle were more effective. This is because large cattle use proportionately less energy for maintenance, which allows more energy to be allocated to growth, lactation and foetal production. When energy was limited to an amount per unit of metabolic weight, small cattle were more efficient than medium and larger cattle in the growth and production phases. Small, medium and large cattle were equally efficient (or inefficient) in the maintenance and lactation phases. Energy requirements of cattle in South Africa are commonly calculated using the Large Stock Unit (LSU). The LSU typically overestimates energy requirements for cattle, except in the lactation phase. When using the LSU to match small, medium or large cattle to a resource base, the LSU overestimates energy requirements of large cattle proportionately more than that of small and medium cattle. This is excluding the lactation phase, where energy requirements for all three sizes are underestimated and that of large cattle underestimated proportionately more. There are more considerations when matching cow size to managerial practices. A smaller body size is a natural adaptation to a semi-arid environment and this adaptation can be expressed in different ways. The number of animals on a resource base has implications on management practices. Having more heads of cattle on a resource base increases genetic variation of the herd, allowing for genetic progress to be made faster than in herd of fewer cattle. / Agriculture and  Animal Health / M.Sc. (Agriculture)
96

Détection et analyse des signaux ultrasonores d'un dispositif Doppler multi-capteurs pour le suivi de l'activité fœtale

KRIBECHE, Ali 30 June 2005 (has links) (PDF)
Ce travail a pour but essentiel de mettre au point des outils permettant une meilleure analyse des signaux Doppler provenant de l'activité fœtale. Il s'inscrit dans le cadre d'un projet RNTS (Réseau National des Technologies pour la Santé) intitulé Actifoetus. Il consiste à traiter les signaux fournis par 12 capteurs ultrasonores placés sur le ventre maternel et reliés à un appareillage Doppler à émission pulsée multivoies, développé par la société Ultrasons Technologies, Tours. Chaque capteur détecte les signaux Doppler produits par les structures fœtales en mouvement à 5 profondeurs successives dans l'utérus maternel. <br />L'objectif principal du projet est d'extraire des paramètres reflétant l'activité fœtale (rythmes cardiaque et pseudo respiratoire, mouvements des membres et du tronc, réponse à des stimuli, ...) pour la surveillance et le suivi des grossesses. Une seconde étape était de définir, à partir de ces données, l'état de bien-être ou de souffrance du fœtus en vue d'un monitorage ambulatoire de certaines grossesses à risque. Cette application en télé médecine nécessitera la mise au point d'un système portable de type Holter. <br />Le travail réalisé a comporté dans un premier temps une participation à la mise au point définitive de l'appareillage et de la méthode de recueil de données. La plus grande partie du travail a ensuite été consacrée à la mise au point et à la validation du traitement des signaux enregistrés sur des grossesses de 20 à 30 semaines. Ces enregistrements ont permis de montrer la qualité des signaux Doppler d'activité fœtale fournis par le système Actifoetus, et de valider l'utilisation de la Transformée de Fourier Rapide (FFT) et de la Fonction d'Autocorrélation (ACF) pour détecter l'activité cardiaque et les mouvements du fœtus. Nous avons pu également montrer que l'Analyse en Composantes Indépendantes (ACI) permet de séparer avec succès un mélange de plusieurs signaux Doppler. <br />La principale originalité du travail réside dans l'extraction d'informations statistiquement pertinentes concernant les mouvements et les rythmes du fœtus à partir de plusieurs capteurs ultrasonores. La mise en correspondance de ces données avec les signaux d'activité de la mère (Accéléromètre), ou de stimuli neurosensoriels, devrait permettre des applications cliniques importantes.<br />Le projet est conçu pour déboucher sur un appareil miniaturisé commercialisable à partir du démonstrateur réalisé. Les aspects de protection industrielle seront examinés aussi bien en ce qui concerne l'appareil holter lui-même, qu'au niveau des algorithmes de traitement et de fusion des données.
97

Hemodynamic and Geometric Changes of the Female Reproductive System in Health and Disease

Jessica L Ma (8799200) 05 May 2020 (has links)
<p>Preterm birth is the leading cause of newborn mortality, with 15 million babies born premature worldwide every year. Children that do survive early delivery are more likely to develop cognitive abnormalities, motor deficits, heart disease, cerebral palsy, and more. While little is known about the pathophysiology of preterm birth, several pregnancy-related complications are related to preterm birth, namely cervical insufficiency and preeclampsia. In the former, premature cervical remodeling and softening can result in the shortening of the cervix, increasing a woman’s risk of preterm birth; this condition is called cervical insufficiency (CI), which is the inability of the cervix to remain closed as a result of weakened tissues. CI is currently measured by a one-dimensional sonographic cervical length, where < 25 mm indicates shortening. Preeclampsia is a disorder that can be explained through the Page kidney phenomenon: compression of the left renal vein (LRV) causes renal venous outflow obstruction, leading to elevated intrarenal pressure and hypertension. The supine pressor test (SPT) is a diagnostic tool for preeclampsia where a positive test is defined by an increase of 20 mmHg in diastolic blood pressure (BP) when shifting from the left lateral recumbent to the supine position. Due to the intense risk of morbidity and mortality for both the mother and the fetus, the need to monitor BP changes is critical. Currently, there is an unmet clinical need to characterize the hemodynamic and geometric properties of the female reproductive organs throughout gestation. Utilizing ultrasound imaging can increase our knowledge about the 3D anatomy and systemic changes during pregnancy, unravel risk factors, establish preventative methods, and standardize treatment plans. In this thesis research, we developed a murine model to 1) examine the pathophysiology of renal vein stenosis, and 2) investigate the effects of stenosis on various cervical dimensions. Renal vein stenosis was found to greatly impact blood flow velocities, as well as cervical width (<i>p<0.05</i>). LRV and cervical area and height also trend towards significance, and there is negative damage to the left kidney and placentae within the stenosed cohort. We also conducted a human study that showed reduced change in postural BP in patients with higher body mass index (BMI). Systolic and diastolic BP in the supine position was significantly greater than in the lateral position for all BMIs with a baseline increase in BP of approximately 9-14 mmHg. These findings suggest that therapeutic positioning and close monitoring of BP could mitigate the risk of developing related disorders in pregnancy.</p>
98

Embryo cryopreservation and transfer to rederive a paternal rabbit line after 18 generations. Evaluation of growth and reproductive traits

Juárez Moreno, Jorge Daniel 01 September 2022 (has links)
Tesis por compendio / [ES] Para evaluar los efectos del proceso de selección en una línea paterna de conejos, se compararon los rasgos de crecimiento y rendimiento reproductivo de la descendencia actual (generación R36) en similar ambiente con una población control rederivada de embriones de una generación anterior (R18). Para reducir/evitar el efecto del proceso de criopreservación sobre los rasgos fenotípicos se rederivaron embriones de la generación actual (R36) y obtener una 3ra población (R37V). Capítulo 1, se compara la R37V y la descendencia de la R36 nacida por inseminación artificial (R37). Hubo diferencias en rasgos de crecimiento postnatal en las 3 generaciones evaluadas, pero no en el crecimiento fetal, componentes del tamaño de la camada y rasgos reproductivos. Así, los procesos de criopreservación y transferencia de embriones causan cambios en rasgos de crecimiento de poblaciones reconstituidas que influyen en las siguientes generaciones, sin producir cambios en los reproductivos. En los siguientes capítulos, para reducir/evitar los efectos del proceso de rederivación, la deriva genética y factores ambientales sobre los rasgos fenotípicos, se usó sólo poblaciones rederivadas para comparar los rendimientos reproductivos y de crecimiento. Capítulo 2, al ser los machos usados para producir dosis seminales en centros de inseminación y granjas, se evaluó si el programa de selección modificaba los rasgos seminales, el proteoma del plasma seminal y de espermatozoides, y la fertilidad del semen al usarla en inseminación artificial. Se analizó el proteoma del plasma seminal y espermatozoides de machos maduros de c/grupo y se prepararon dosis seminales para inseminación. Sólo el porcentaje de espermatozoides anormales mostró diferencias, presentando los R21 menos espermatozoides anormales que los R39. El análisis discriminante (DA-PLS) mostró efecto de la generación para el proteoma plasmático y espermático. En plasma seminal, se reportaron 64 proteínas diferencialmente expresadas y 56 sobreexpresadas en R39 (87,5%). Del proteoma de espermatozoides 132 diferencialmente abundantes y 89 sobreexpresadas en R39 (67,4%). A pesar de las diferencias en importantes proteínas relacionadas con la capacitación, la motilidad, la inmunoprotección de espermatozoides y la fecundación, no hubo diferencias en fertilidad y prolificidad con las dosis seminales para inseminación. Capítulo 3, se analizó el efecto de la selección por ganancia media diaria de peso (GMD) post-destete después de 37 generaciones. Tras 2 generaciones post rederivación (R21 vs. R39), todos los caracteres evaluados mostraron progreso resultado de la selección, y no afecta a los parámetros estimados de la curva de crecimiento de Gompertz. Los resultados demuestran que el programa de selección mejoró la GMD sin variar el peso corporal adulto, pero tras 37 generaciones de selección, este carácter parece agotado. Capítulo 4, comparamos los parámetros reproductivos de conejas entre las poblaciones rederivadas y control. Los rasgos de desarrollo prenatal y los componentes del tamaño de camada se midieron en la 2da generación post rederivación (R20 y R38). Así la selección por GMD no tiene efectos adversos sobre los componentes del tamaño de la camada, y el área del saco fetal al día 12 de gestación, área de la placenta fetal y la longitud cráneo-rabadilla del feto al 19 de gestación fueron mayores en R38. Resultados muestran que la selección por GMD no afecta negativamente el rendimiento reproductivo. Conclusión, el estudio demuestra que los efectos de la criopreservación sobre los rasgos de crecimiento persisten dos generaciones post rederivación. Además, la línea muestra signos de agotamiento del progreso genético quizás por el bajo rendimiento reproductivo y elevada mortalidad postnatal. La selección por GMD influyó en cambios del crecimiento fetal y del proteoma del eyaculado, sin afectar al rendimiento reproductivo de hembras ni la fertilidad y prolificidad de las dosis seminales de machos. / [CA] Per avaluar els efectes del procés de selección en una línia paterna de conills, es van comparar els trets de creixement i el rendiment reproductiu de la descendència de la generació actual (R36) sota el mateix entorn amb una població control derivada dels embrions emmagatzemats d'una generació anterior (R18). Per reduir/evitar l'efecte del procés de criopreservació embrions de la generació actual (R36) es van criopreservar i transferir (rederivar) per obtenir una 3a població (R37V). Capítol 1, es compara la generació R37V i la descendència de la 36a generació nascuda per inseminació artificial (R37). Hi ha diferències en els trets de creixement postnatal a les tres generacions avaluades. Tot i que el creixement fetal, els components de la mida de la ventrada i els trets reproductius no van mostrar diferències. La rederivació provoquen canvis en els trets de creixement de les poblacions reconstituïdes que influeixen en les generacions següents, sense canvis en els trets reproductius. En els capítols següents, per reduir/evitar els efectes del procés de rederivació, la deriva genètica i els factors ambientals sobre els trets fenotípics, es van utilitzar les poblacions rederivades per comparar els rendiments reproductius i de creixement. Capítol 2, ja que els mascles s'utilitzaven per produir dosis de semen en centres d'inseminació i granges, es va estudiar si un programa de selecció per guany mitja de pes diari pot canviar els trets seminals, el proteoma del plasma i dels espermatozoides i la fertilitat del semen en la inseminació artificial. Només el percentatge d'espermatozoides anormals mostra diferències significatives, R21 presentant menys espermatozoides anormals que R39. L'anàlisi discriminant (DA-PLS) mostra efecte de la generació al proteoma del plasma i dels espermatozoides. En plasma seminal, 64 proteïnes es van expressar de manera diferent, 56 sobre-expressades en R39 (87,5%). El proteoma de l'esperma 132 proteïnes diferencialment abundants, 89 sobre-expressades en R39 (67,4%). Tot i observar diferències en proteïnes importants relacionades amb la capacitat, la motilitat o la immunoprotecció dels espermatozoides i la fecundació, La fertilitat i la prolificitat es van detectar quan es van utilitzar dosis seminals comercials per a la inseminació. Capítol 3, vam avaluar l'efecte d'una selecció a llarg termini per a l'augment de pes mitjà diari (ADG). Després de dues generacions d'ambdues poblacions rederivades (R21 vs. R39), tots els trets avaluats mostra algun progrés. Aquesta resposta no sembla afectar els paràmetres estimats de la corba de creixement de Gompertz. Resultats demostra que el programa de selecció havia millorat l'ADG sense variacions en pes corporal adult, però després de 37 generacions de selecció, aquest tret sembla esgotat. Capítol 4, compara els trets reproductius entre poblacions femenins entre ambdues poblacions (rederivades i control). El desenvolupament fetal i els components de la mida de la ventrada es mesura els trets a la segona generació després de la rederivació (R20 i R38). Resultats suggereix que la selecció per ADG no té cap efecte advers sobre els components de la mida de la ventrada i la zona del sac fetal el dia 12 de gestació i la zona de la placenta fetal i la longitud de la corona-gropa del fetus el dia 19 de gestació eren més grans a la R38. La selecció per ADG no afecta negativament els components de la mida de la ventrada, el creixement fetal i el rendiment reproductiu. Nostre estudi proporciona més proves dels efectes de la criopreservació sobre els trets de creixement que persisteixen dues generacions després de la rederivació. La línia va mostrar signes d'esgotament del progrés genètic per baix rendiment reproductiu i l'alta mortalitat postnatal. La selecció per ADG va influir en els canvis en el creixement fetal i en el proteoma ejaculat, però no va afectar el rendiment reproductiu de les femelles ni la fertilitat i la prolificitat de les dosis seminals dels mascles. / [EN] To evaluate the effects of the selection process in a paternal line of rabbits, growth traits and reproductive performance from the offspring of the current generation (R36) were compared under the same environment with a control population rederived from embryos stored of a previous generation (R18). To reduce or avoid the effect of the cryopreservation process on phenotypic traits embryos of current generation (R36) were cryopreserved and transferred to obtain a third population (R37V). In chapter 1, R37V generation and offspring of 36th generation born by artificial insemination (generation R37) were compared. Differences in postnatal growth traits were observed in the three generations assessed. Although foetal growth, litter size components and reproductive traits did not show significant differences. In conclusion, cryopreservation and embryo transfer processes cause changes in growth traits of reconstituted populations that influence the following generations, without changes in reproductive traits. In the following chapters, to reduce or avoid the effects of the rederivation process, genetic drift and environmental factors on phenotypic traits, only the rederived populations were used to compare reproductive and growth performances. In chapter 2, considering that males were used to produce semen doses at insemination centres and farms, we studied whether a programme of selection by daily gain changed the seminal traits, plasma and sperm proteome and the fertility of semen when used in artificial insemination. Seminal plasma and sperm proteome from mature males of each group were analysed and semen doses were used to inseminate females. Only the percentage of abnormal sperm showed significant differences, R21 presented fewer abnormal sperm than R39. The discriminant analysis (DA-PLS) showed an effect of the generation for plasma and sperm proteome. In seminal plasma, 64 proteins were differentially expressed, 56 were overexpressed in R39 (87.5%). Sperm proteome reported 132 differentially abundant proteins, 89 were overexpressed in R39 (67.4%). Despite differences in important proteins related to capacitation, sperm motility or immunoprotection and to the fertilization process, no differences in fertility and prolificacy were detected when commercial seminal doses were used for insemination. In chapter 3, we evaluated the effect of a long-term selection for post-weaning average daily weight gain (ADG) over 37 generations. After two generations of both rederived populations (R21 vs. R39 generations), all evaluated traits showed some progress as a result of the selection. This response does not seem to affect the estimated Gompertz growth curve parameters. Results demonstrated that the selection programme had improved ADG without variations in adult body weight but, after 37 generations of selection, this trait seems exhausted. In chapter 4, we compared female reproductive traits between both rabbit populations (rederived and control). Foetal growth and litter size traits were measured in the second generation after rederivation (R20 and R38 generations). Our study suggests that selection for growth rate has no adverse effect on litter size components and the foetal sac area at day 12 of gestation, and foetal placenta area and crown-rump length of the foetus at day 19 of gestation were higher in the R38 generation. These results show that selection for growth rate does not adversely affect on reproductive performance. In conclusion, our study provides further evidence of the effects of cryopreservation on growth traits persisting two generations after rederivation. Moreover, the paternal line showed signs of genetic progress exhaustion due to low reproductive performance and high postnatal mortality. Selection by daily weight gain influenced changes in foetal growth and ejaculate proteome, but did not affect the reproductive performance of females or the fertility of seminal doses of males. / This research was supported by AGL2017-85162-C2-1-R research project funded by Ministerio de Economía, Industria y Competitividad (MICINN, Spain). Funding for open access charge: CRUE- Universitat Politècnica de València. / Juárez Moreno, JD. (2022). Embryo cryopreservation and transfer to rederive a paternal rabbit line after 18 generations. Evaluation of growth and reproductive traits [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/185071 / TESIS / Compendio
99

Analyse et extraction de paramètres de complexité de signaux biomédicaux / Analysis and extraction of complexity parameters of biomedical signals

Zaylaa, Amira 15 December 2014 (has links)
L'analyse de séries temporelles biomédicales chaotiques tirées de systèmes dynamiques non-linéaires est toujours un challenge difficile à relever puisque dans certains cas bien spécifiques les techniques existantes basées sur les multi-fractales, les entropies et les graphes de récurrence échouent. Pour contourner les limitations des invariants précédents, de nouveaux descripteurs peuvent être proposés. Dans ce travail de recherche nos contributions ont porté à la fois sur l’amélioration d’indicateurs multifractaux (basés sur une fonction de structure) et entropiques (approchées) mais aussi sur des indicateurs de récurrences (non biaisés). Ces différents indicateurs ont été développés avec pour objectif majeur d’améliorer la discrimination entre des signaux de complexité différente ou d’améliorer la détection de transitions ou de changements de régime du système étudié. Ces changements agissant directement sur l’irrégularité du signal, des mouvements browniens fractionnaires et des signaux tirés du système du Lorenz ont été testés. Ces nouveaux descripteurs ont aussi été validés pour discriminer des fœtus en souffrance de fœtus sains durant le troisième trimestre de grossesse. Des mesures statistiques telles que l’erreur relative, l’écart type, la spécificité, la sensibilité ou la précision ont été utilisées pour évaluer les performances de la détection ou de la classification. Le fort potentiel de ces nouveaux invariants nous laisse penser qu’ils pourraient constituer une forte valeur ajoutée dans l’aide au diagnostic s’ils étaient implémentés dans des logiciels de post-traitement ou dans des dispositifs biomédicaux. Enfin, bien que ces différentes méthodes aient été validées exclusivement sur des signaux fœtaux, une future étude incluant des signaux tirés d’autres systèmes dynamiques nonlinéaires sera réalisée pour confirmer leurs bonnes performances. / The analysis of biomedical time series derived from nonlinear dynamic systems is challenging due to the chaotic nature of these time series. Only few classical parameters can be detected by clinicians to opt the state of patients and fetuses. Though there exist valuable complexity invariants such as multi-fractal parameters, entropies and recurrence plot, they were unsatisfactory in certain cases. To overcome this limitation, we propose in this dissertation new entropy invariants, we contributed to multi-fractal analysis and we developed signal-based (unbiased) recurrence plots based on the dynamic transitions of time series. Principally, we aim to improve the discrimination between healthy and distressed biomedical systems, particularly fetuses by processing the time series using our techniques. These techniques were either validated on Lorenz system, logistic maps or fractional Brownian motions modeling chaotic and random time series. Then the techniques were applied to real fetus heart rate signals recorded in the third trimester of pregnancy. Statistical measures comprising the relative errors, standard deviation, sensitivity, specificity, precision or accuracy were employed to evaluate the performance of detection. Elevated discernment outcomes were realized by the high-order entropy invariants. Multi-fractal analysis using a structure function enhances the detection of medical fetal states. Unbiased cross-determinism invariant amended the discrimination process. The significance of our techniques lies behind their post-processing codes which could build up cutting-edge portable machines offering advanced discrimination and detection of Intrauterine Growth Restriction prior to fetal death. This work was devoted to Fetal Heart Rates but time series generated by alternative nonlinear dynamic systems should be further considered.
100

BIRTHWEIGHT AND SUSCEPTIBILITY TO CHRONIC DISEASE

Issa Al Salmi Unknown Date (has links)
The thesis examines the relationship of birthweight to risk factors and markers, such as proteinuria and glomerular filtration rate, for chronic disease in postnatal life. It made use of the Australian Diabetes, Obesity and Lifestyle Study (AusDiab). The AusDiab study is a cross sectional study where baseline data on 11,247 participants were collected in 1999-2000. Participants were recruited from a stratified sample of Australians aged ≥ 25 years, residing in 42 randomly selected urban and non-urban areas (Census Collector Districts) of the six states of Australia and the Northern Territory. The AusDiab study collected an enormous amount of clinical and laboratory data. During the 2004-05 follow-up AusDiab survey, questions about birthweight were included. Participants were asked to state their birthweight, the likely accuracy of the stated birthweight and the source of their stated birthweight. Four hundred and twelve chronic kidney disease (CKD) patients were approached, and 339 agreed to participate in the study. The patients completed the same questionnaire. Medical records were reviewed to check the diagnoses, causes of kidney trouble and SCr levels. Two control subjects, matched for gender and age, were selected for each CKD patient from participants in the AusDiab study who reported their birthweight. Among 7,157 AusDiab participants who responded to the questionnaire, 4,502 reported their birthweights, with a mean (standard deviation) of 3.4 (0.7) kg. The benefit and disadvantages of these data are discussed in chapter three. The data were analysed for the relationship between birthweight and adult body size and composition, disorders of glucose regulation, blood pressure, lipid abnormalities, cardiovascular diseases and glomerular filtration rate. Low birthweight was associated with smaller body build and lower lean mass and total body water in both females and males. In addition low birthweight was associated with central obesity and higher body fat percentage in females, even after taking into account current physical activity and socioeconomic status. Fasting plasma glucose, post load glucose and glycosylated haemoglobin were strongly and inversely correlated with birthweight. In those with low birthweight (< 2.5 kg), the risks for having impaired fasting glucose, impaired glucose tolerance, diabetes and all abnormalities combined were increased by 1.75, 2.22, 2.76 and 2.28 for females and by 1.40, 1.32, 1.98 and 1.49 for males compared to those with normal birthweight (≥ 2.5 kg), respectively. Low birthweight individuals were at higher risk for having high blood pressure ≥ 140/90 mmHg and ≥ 130/85 mmHg compared to those with normal birthweight. People with low birthweight showed a trend towards increased risk for high cholesterol (≥ 5.5 mmol/l) compared to those of normal birthweight. Females with low birthweight had increased risk for high low density lipoprotein cholesterol (≥ 3.5 mmol/l) and triglyceride levels (≥ 1.7 mmol/l) when compared to those with normal birthweight. Males with low birthweight exhibited increased risk for low levels of high density lipoprotein cholesterol (<0.9 mmol/l) than those with normal birthweight. Females with low birthweight were at least 1.39, 1.40, 2.30 and 1.47 times more likely to have angina, coronary artery disease, stroke and overall cardiovascular diseases respectively, compared to those ≥ 2.5 kg. Similarly, males with low birthweight were 1.76, 1.48, 3.34 and 1.70 times more likely to have angina, coronary artery disease, stroke and overall cardiovascular diseases compared to those ≥ 2.5 kg, respectively. The estimated glomerular filtration rate was strongly and positively associated with birthweight, with a predicted increase of 2.6 ml/min (CI 2.1, 3.2) and 3.8 (3.0, 4.5) for each kg of birthweight for females and males, respectively. The odd ratio (95% confidence interval) for low glomerular filtration rate (<61.0 ml/min for female and < 87.4 male) in people of low birthweight compared with those of normal birthweight was 2.04 (1.45, 2.88) for female and 3.4 (2.11, 5.36) for male. One hundred and eighty-nineCKD patients reported their birthweight; 106 were male. Their age was 60.3(15) years. Their birthweight was 3.27 (0.62) kg, vs 3.46 (0.6) kg for their AusDiab controls, p<0.001 and the proportions with birthweight<2.5 kg were 12.17% and 4.44%, p<0.001. Among CKD patients, 22.8%, 21.7%, 18% and 37.6% were in CKD stages 2, 3, 4 and 5 respectively. Birthweights by CKD stage and their AusDiab controls were as follows: 3.38 (0.52) vs 3.49 (0.52), p=0.251 for CKD2; 3.28 (0.54) vs 3.44 (0.54), p=0.121 for CKD3; 3.19 (0.72) vs 3.43 (0.56), p= 0.112 for CKD4 and 3.09 (0.65) vs 3.47 (0.67), p<0.001 for CKD5. The results demonstrate that in an affluent Western country with a good adult health profile, low birthweight people were predisposed to higher rates of glycaemic dysregulation, high blood pressure, dyslipidaemia, cardiovascular diseases and lower glomerular filtration rate in adult life. In all instances it would be prudent to adopt policies of intensified whole of life surveillance of lower birthweight people, anticipating this risk. The general public awareness of the effect of low birthweight on development of chronic diseases in later life is of vital importance. The general public, in addition to the awareness of people in medical practice of the role of low birthweight, will lead to a better management of this group of our population that is increasingly surviving into adulthood.

Page generated in 0.0448 seconds