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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 34 for “"sperm cells"”.
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Chemotaxis of Sperm Cells
Sperm cells are guided to the egg by chemoattractants in many species. Sperm cells are propelled in a liquid by the regular beat of their flagellum. In the presence of a concentration gradient of a chemoattractant, they can steer upwards the concentration gradient, a process called chemotaxis. Eggs …
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DNA profiling of single sperm cells and single skin flakes in forensics using micromanipulation and whole genome amplification.
… to a DNA sample. By DNA profiling of single spermatozoa and skin flakes, problems associated with mixed profile could ideally be overcome. However, PCR is not a sensitive enough method to generate DNA profiles by STRs on single cells. Moreover, high quality intact DNA is required, but is not …
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Attempts to isolate highly viable, morphologically normal, Y- chromosome-bearing bovine spermatozoa
… normal, Y-chromosome-bearing bovine spermatozoa. The column consisted of a 500 ml separatory funnel in which 26 ml of extended semen was layered on top of a discontinuous gradient of 4% BSA (60 ml) over 10% BSA (60 ml). Results indicated that the greatest percentage of the applied …
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Characterization of Phosphatidylserine Expression in Bovine Sperm
… expression of phosphatidylserine (PS) on bovine sperm and investigate what factors may impact it, as previous research demonstrated that phosphatidylserine (PS) plays a role in murine fertilization. Despite conventionally being an apoptotic marker, it is present on viable and …
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Spermatogenesis in the sand crab Emerita Analoga
<p>Crustacean spermatozoa are among the most peculiarly modified germ cells in the animal kingdom. Many of their striking cytological specializations may be observed in the sperm cells or Emerita analoga, the so-called sand crab. This animal has been used by the writer for studies on …
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The Use And Development Of Laser Microdissection To Separate Spermatozoa From Epithelial Cells For Str Analysis
… when cell separation of the sexual assailant's sperm from the victim's cells is incomplete. The forensic community continues to seek improvements in cell separation methods from mixtures for DNA typing. This report describes the use of laser microdissection (LMD) for the separation of pure …
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Determination of the effects of caffeine C1, 3. 7- trimethylxanthine in Tris-based egg yolk extender and different incubation intervals on the quality of cryopreserved bull semen
… used to maintain the structure and function of cells by halting their metabolism and enzymatic activity at cryogenic temperatures. Cryopreservation induces structural and functional damage to bovine spermatozoa, resulting in reduced post-thaw fertility potential. Caffeine's ability to modify …
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Analyzing the Longevity of Sperm Within the Female Japanese Quail by Assessing Sperm Penetration of the Perivitelline Layer Under Optimal and Suboptimal Conditions.
… semen within the female reproductive tract. The sperm storage tubules will store and subsequently release semen to travel up the oviduct. Sperm cells that make the trek up the oviduct have a chance to fertilize the ovum. These sperm cells will bind to the perivitelline layer of the ovum and …
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Comparison of results using temperature controlled differential extraction and differential extraction using the QIAGEN EZ1 advanced
… extract the deoxyribonucleic acid (DNA) from the cells, it is hard for labs to keep up with the demand. The extraction method used is called differential extraction, where the epithelial cells from the victim are separated from the sperm cells from the perpetrator into different fractions. The …
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Evaluation of Tom Fertility as Affected by Dietary Fatty Acid Composition
… fertility, motility, perivitelline layer sperm penetration percent, and live vs. dead sperm were analyzed. Whereas body weight increased linearly from 31 to 56 weeks of age (WOA), there was no effect of dietary treatment. As measured by the Accudenz® procedure, there were differences in …
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A Forward Genetic Screen Revealed the Role of POLDIP2 in Ensuring Maternal Inheritance of Mitochondrial DNA in Drosophila melanogaster
… genomes are eliminated in the late stages of spermatogenesis. In *Drosophila melanogaster*, two nuclear-encoded mitochondrial proteins, EndoG and PolG1, were shown to participate in the elimination of the paternal mtDNA (DeLuca & O'Farrell, 2012; Yu et al., 2017). However, many details of this …
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Negative biomarkers of sperm quality and male fertility
… light microscopy provides information about sperm motility and basic morphology but has a limited ability to predict reproductive performance in an assisted reproduction setting. In-depth analysis carried out quickly and with repeatable precision on a large number of sperm cells is important …
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Immunological castration of boars temporarily reduces testosterone concentration, testis size and function, without long term effects on libido and sperm quality
… Semen volume, gel weight and total number of sperm cells were not different among treatments. Sperm concentration was greater for DI than SI (P = 0.011), and tended to be greater for DI compared to CNT (P = 0.102). Sperm motility tended to be greater for DI boars compared to CNT boars (P = …
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Confocal Characterization of the Apical Testes and Ultrastructural Analysis of the Seminal Visicles of Drosophila pseudoobscura
… (which plays a pivotal role in the initiation of spermatogenesis) using antibodies available for the D. melanogaster testes. Using immunofluorescence techniques, we have characterized D. pseudoobscura adherent proteins in a specific region termed "the hub" responsible for maintaining the cells …
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Magnetic Micromotors in Assisted Reproductive Technology
… First, as synthetic motor units for individual sperm cells, representing a novel approach to counteract sperm immotility (asthenozoospermia), which is one of the most prevalent causes of male infertility. Second, as synthetic carriers of fertilized oocytes (zygotes) towards the realization of …
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Microsurgical Fertilization of Mammalian Eggs: An Assessment of Clinical Utilization
… fertilization is the technique in which a spermatozoon or sperm nucleus is injected into the cytoplasm of an egg. To establish a foundation for the use of microsurgical fertilization as a means of treating infertility, this study evaluated the procedure in hamster and human eggs. Hamster …
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Acrosomal molecules exposure during human sperm capacitation
At ejaculation sperm cells cannot fertilize. They need to undergo a series of molecular modifications to achieve competency. Surprisingly,molecular markers for identifying sperm populations competent to fertilize are not robust. However, recently an intra - acrosomal protein exposed at the …
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(Im)possible baby : how to stimulate discussions about possibilities of two-mum and two-dad children
… because of the possibility of making egg and sperm cells from parents of the same sex," he said."2 Is creating a baby from same-sex parents the ethical thing to do? Who has the right to decide this, and how? This project aims to design and inspire debate about the bioethics of producing babies …
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Utilization of nanostructured surfaces for sensing applications and the use of nanoentities for the fabrication of new materials
… for the patterned immobilization of human spermatozoa cells. Such arrays would allow for the investigation of specific individual sperm cells. This could have a use in the field of artificial insemination. Chapter 6 utilizes citrate passivated Au nanoparticles to prepare composite PEO/Au …
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Spermatogenesis and oogenesis of Haemonchus contortus, a nematode parasitic in the abomasum of sheep and other ruminants
… with the development of the reproductive cells of this species. In the present work a study has been made of spermatogenesis and oogenesis with some attention directed to methods of copulation, the passage of the sperm cells upon entrance into the vulva and the anatomical location in the …
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