160 research outputs found

    Personal photography and the personal computer

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    Thesis (M.S.V.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1985.MICROFICHE COPY AVAILABLE IN ARCHIVES AND ROTCH.Includes bibliographical references (leaves 78-85).A system for the capture and combination of video images is proposed as a prototype for a future personal computer that allows free manipulation and intermixing of information from the computer, video, and photography domains. The benefits in power, flexibility, and applicability to each area from combining with the others are explored. The history and development of the three media contributing to the work is briefly examined, as are the techniques usable in moving between and combining them. The "Moviecliptool" system is described. Moviecliptool's purpose is to allow the generation of high quality stills from a recorded video sequence; that is, moving from the video to the photography domain via the computer. It allows the user to capture a sequence of frames from conventional video equipment into the computer. the frames are brought up on an interactive display where the user can select among them, view them in detail, and, more importantly, begin to combine them to his taste. Moviecliptool provides tools for image enhancements to try to alleviate the noise problems inherent in the video medium, as well as interactive tools for manipulating the content of the images, either by direct modification or by selective combination of the images. The environment supporting moviecliptool is extensively described, as it has helped shape the design of the system. Future developments and directions for similar systems are discussed. The appearance in the commercial world of relevant systems is seen as heralding a promising future for tools which transcend media boundaries.by Leo Hourvitz.M.S.V.S

    HCG (1500IU) administration on day 3 after oocytes retrieval, following GnRH-agonist trigger for final follicular maturation, results in high sufficient mid luteal progesterone levels - a proof of concept

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    BACKGROUND: Controlled ovarian hyperstimulation (COH) which combining GnRH antagonist co-treatment and GnRH agonist trigger with an additional 1500 IU hCG luteal rescue on day of oocytes retrieval, has become a common tool aiming to reduce severe ovarian hyperstimulation syndrome (OHSS). In the present, proof of concept study, we evaluate whether by deferring the hCG rescue bolus for 3 days, we are still able to rescue the luteal phase. METHODS: Patients undergoing the GnRH-antagonist protocol, who were considered at high risk for developing severe OHSS and received GnRH-agonist for final oocyte maturation, were included. For luteal phase support, all patients received an “intense” luteal support. Those who had no signs of early moderate OHSS on day 3 after oocytes retrieval were instructed to inject 1500 IU of HCG bolus (hCG group). Ovarian stimulation characteristics and mid luteal progesterone levels were compared between those who received the HCG bolus and those who did not. RESULTS: Eleven IVF cycles were evaluated, 5 in the hCG group and 6 in the intense luteal support only group. While no in-between group differences were observed in ovarian stimulation characteristics, significantly higher mid luteal progesterone levels (>127 nmol/L vs 42.1 ± 14.5 nmol/L, respectively) and a non-significant increase in pregnancy rate (40% vs 16.6%, respectively), were observed in those who receive the hCG bolus compared to those who did not. CONCLUSIONS: hCG luteal rescue should be offered 3 days after oocytes retrieval only to those patients with no signs of early moderate OHSS. Further studies are required to elucidate the appropriate regimen of luteal HCG administration in patients undergoing final follicular maturation with GnRH-agonist

    Trophoblast attachment to the endometrial epithelium elicits compartment-specific transcriptional waves in an in-vitro model

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    Implantation is a major bottleneck in human reproduction (Polanski et al., 2014). The average implantation rate for an embryo ranges from 30% to 40% (Coughlan et al., 2014). Recurrent implantation failure (RIF) is estimated to occur in approximately 4% of IVF cycles (Koot et al., 2012), although estimates vary because there are several somewhat different definitions of RIF in the literature. Implantation of the blastocyst in the receptive endometrium is a sequential process involving apposition, attachment and invasion that precedes the establishment of pregnancy (Wang and Dey, 2006). Successful implantation requires embryo competence and endometrial receptivity, both of which are dynamic and highly regulated states (Wang and Dey, 2006). In addition to genetic disorders (which are a major cause of implantation failure and miscarriage), embryo competence, quality and ultimately developmental potential depend on the embryo achieving the correct regulatory, signalling and metabolic states (Fu et al., 2009; Hourvitz et al., 2006; Lundin et al., 2001; Simon and Laufer, 2012; Sjoblom et al., 2006). A key determinant of these embryonic states is their underlying transcriptional dynamics; for instance, waves of embryonic transcriptional activation direct early development and the symmetry breaking needed for cell fate specification (Shi et al., 2015; Vassena et al., 2011).info:eu-repo/semantics/publishedVersio

    Paternal effects on early embryogenesis

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    Historically, less attention has been paid to paternal effects on early embryogenesis than maternal effects. However, it is now apparent that certain male factor infertility phenotypes are associated with increased DNA fragmentation and/or chromosome aneuploidies that may compromise early embryonic development. In addition, there is a growing body of evidence that the fertilizing sperm has more function than just carrying an intact, haploid genome. The paternally inherited centrosome is essential for normal fertilization, and the success of higher order chromatin packaging may impact embryogenesis. Epigenetic modifications of sperm chromatin may contribute to the reprogramming of the genome, and sperm delivered mRNA has also been hythesized to be necessary for embryogenesis. There is less information about the epigenetic factors affecting embryogenesis than genetic factors, but the epigenetics of gamete and early embryogenesis is a rapidly advancing field

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