151 research outputs found
Rawls and Political Realism: Realistic Utopianism or Judgement in Bad Faith?
Political realism criticises the putative abstraction, foundationalism and neglect of the agonistic dimension of political practice in the work of John Rawls. This paper argues that had Rawls not fully specified the implementation of his theory of justice in one particular form of political economy then he would be vulnerable to a realist critique. But he did present such an implementation: a property-owning democracy. An appreciation of Rawls s specificationist method undercuts the realist critique of his conception of justice as fairness
Pioneering contributions by Robert Edwards to oocyte in vitro maturation (IVM)
The history of in vitro maturation (IVM) of mammalian oocytes, especially of human oocytes, holds a special place for Robert Edwards. He was the first to comprehensively examine and demonstrate maturation of human oocytes in vitro and in so doing he changed the course of medicine by fertilizing them in vitro. In reviewing his contribution, we have examined the state of the field at the time and discuss his pioneering insights into mammalian oocyte biology. We will also discuss how some of the major concepts and challenges identified by Edwards 50 years ago remain among the major challenges facing IVM today.J.G. Thompson and R.B. Gilchris
EGF increases expression and activity of PAs in preimplantation rat embryos and their implantation rate
BACKGROUND: Embryo implantation plays a major role in embryogenesis and the outcome of pregnancy. Plasminogen activators (PAs) have been implicated in mammalian fertilization, early stages of development and embryo implantation. As in-vitro developing embryos resulted in lower implantation rate than those developed in-vivo we assume that a reduced PAs activity may be involved. In the present work we studied the effect of EGF on PAs activity, quantity and embryo implantation. METHODS: Zygotes were flushed from rat oviducts on day one of pregnancy and grown in-vitro in R1ECM supplemented with EGF (10 ng/ml) and were grown up to the blastocyst stage. The control groups were grown in the same medium without EGF. The distribution and quantity of the PAs were examined using fluorescence immunohistochemistry followed by measurement of PAs activity using the chromogenic assay. Implantation rate was studied using the embryo donation model. RESULTS: PAs distribution in the embryos was the same in EGF treated and untreated embryos. Both PAs were localized in the blastocysts' trophectoderm, supporting the assumption that PAs play a role in the implantation process in rats. EGF increased the quantity of uPA at all stages studied but the 8-cell stage as compared with controls. The tissue type PA (tPA) content was unaffected except the 8-cell stage, which was increased. The activity of uPA increased gradually towards the blastocyst stage and more so due to the presence of EGF. The activity of tPA did not vary with the advancing developmental stages although it was also increased by EGF. The presence of EGF during the preimplantation development doubled the rate of implantation of the treated group as compared with controls
Reversible Disassembly of the Actin Cytoskeleton Improves the Survival Rate and Developmental Competence of Cryopreserved Mouse Oocytes
Effective cryopreservation of oocytes is critically needed in many areas of human reproductive medicine and basic science, such as stem cell research. Currently, oocyte cryopreservation has a low success rate. The goal of this study was to understand the mechanisms associated with oocyte cryopreservation through biophysical means using a mouse model. Specifically, we experimentally investigated the biomechanical properties of the ooplasm prior and after cryopreservation as well as the consequences of reversible dismantling of the F-actin network in mouse oocytes prior to freezing. The study was complemented with the evaluation of post-thaw developmental competence of oocytes after in vitro fertilization. Our results show that the freezing-thawing process markedly alters the physiological viscoelastic properties of the actin cytoskeleton. The reversible depolymerization of the F-actin network prior to freezing preserves normal ooplasm viscoelastic properties, results in high post-thaw survival and significantly improves developmental competence. These findings provide new information on the biophysical characteristics of mammalian oocytes, identify a pathophysiological mechanism underlying cryodamage and suggest a novel cryopreservation method
Preserving and Using Germplasm and Dissociated Embryonic Cells for Conserving Caribbean and Pacific Coral
Coral reefs are experiencing unprecedented degradation due to human activities, and protecting specific reef habitats may not stop this decline, because the most serious threats are global (i.e., climate change), not local. However, ex situ preservation practices can provide safeguards for coral reef conservation. Specifically, modern advances in cryobiology and genome banking could secure existing species and genetic diversity until genotypes can be introduced into rehabilitated habitats. We assessed the feasibility of recovering viable sperm and embryonic cells post-thaw from two coral species, Acropora palmata and Fungia scutaria that have diffferent evolutionary histories, ecological niches and reproductive strategies. In vitro fertilization (IVF) of conspecific eggs using fresh (control) spermatozoa revealed high levels of fertilization (>90% in A. palmata; >84% in F. scutaria; P>0.05) that were unaffected by tested sperm concentrations. A solution of 10% dimethyl sulfoxide (DMSO) at cooling rates of 20 to 30°C/min most successfully cryopreserved both A. palmata and F. scutaria spermatozoa and allowed producing developing larvae in vitro. IVF success under these conditions was 65% in A. palmata and 53% in F. scutaria on particular nights; however, on subsequent nights, the same process resulted in little or no IVF success. Thus, the window for optimal freezing of high quality spermatozoa was short (âŒ5 h for one night each spawning cycle). Additionally, cryopreserved F. scutaria embryonic cells hadâŒ50% post-thaw viability as measured by intact membranes. Thus, despite some differences between species, coral spermatozoa and embryonic cells are viable after low temperature (â196°C) storage, preservation and thawing. Based on these results, we have begun systematically banking coral spermatozoa and embryonic cells on a large-scale as a support approach for preserving existing bio- and genetic diversity found in reef systems
Simultaneous assessment of plasmatic, acrosomal, and mitochondrial membranes in ram sperm by fluorescent probes
Die rechtliche Regelung des Instituts der kostenlosen Rechtshilfe in der Republik Kroatien mit besonderer BerĂŒcksichtigung der gesetzlichen Regelungen in den postjugoslawischen Staaten
âPravo i pravdu neÄemo nikome prodati, uskratiti ili odgoditi.â
40. paragraf Velike povelje sloboda
Pravo na pristup pravosuÄu (access to justice) jedno je od temeljnih ljudskih prava. Ostvarivanje toga prava uvelike ovisi o dostupnosti pravne pomoÄi svim graÄanima bez obzira na njihov socioekonomski status. Stoga je postojanje uÄinkovitog sustava besplatne pravne pomoÄi u svakoj zemlji jedan od temeljnih jamaca ostvarivanja ljudskih prava u svakodnevnom ĆŸivotu. U radu se razmatra razvoj i ureÄenje instituta besplatne pravne pomoÄi u Republici Hrvatskoj te u ostalim postjugoslavenskim drĆŸavama s ciljem regionalnog prikaza njegova ureÄenja.«To no one will we sell, to no one will we refuse or delay, right or justice» 40th paragraph of the Magna Charta The paper considers the development and regulation of the institute of legal aid in the Republic of Croatia and in the other post-Yugoslav states with the aim of providing a regional outline of their regulation. In recent years legislators in the post-Yugoslav states have been increasingly involved in the regulation of legal aid and, in order to develop modern legal systems, they adopted laws aimed at ensuring and protecting the right to legal aid. The normative activities for regulating legal aid began with the constitutional guarantee for such aid, and were made effective by the provisions of the criminal codes and the civil procedure acts. Later, under the influence of the acquis communautaire of the modern European states they were to be included in the provisions of separate laws of the post-Yugoslav states. This shows that there was an evolution in the development of the right to legal aid, not only as the right to such aid in the form of good will and charity of the state, but also as one of the fundamental human rights guaranteed by constitutional and legal norms.âNiemandem werden wir Recht oder Gerechtigkeit verkaufen, verweigern oder verzögern.â Magna Carta, § 40 In dieser Arbeit werden die Entwicklung und Regelung des Instituts der kostenlosen Rechtshilfe in der Republik Kroatien und in den anderen postjugoslawischen Staaten erörtert, wodurch seine Regelung in der Region dargestellt werden soll. In den letzten Jahren ist die Regelung des Anspruchs auf kostenlose Rechtshilfe zu einer wichtigen Aufgabe fĂŒr die Gesetzgeber in den postjugoslawischen Staaten geworden, die zwecks Aufbau moderner Rechtsordnungen Gesetze verabschiedeten, deren Gegenstand die Wahrnehmung und der Schutz des Rechts auf kostenlose Rechtshilfe ist. Die normative AktivitĂ€t zur Einrichtung der kostenlosen Rechtshilfe begann mit der Verfassungsgarantie des Rechtsanspruches auf kostenlose Rechtshilfe, die in den Bestimmungen der Straf- und der Zivilprozessordnung ihren konkreten Niederschlag fanden, um sich unter dem Einfluss der Trends in der Gesetzgebung der modernen europĂ€ischen Staaten zu Bestimmungen in Sondergesetzen der postjugoslawischen Staaten zu verwandeln. Dies belegt eine Evolution in der Entwicklung des Rechtsanspruchs auf kostenlose Rechtshilfe als nicht allein des Anspruchs auf Hilfe in Form einer wohltĂ€terischen Geste von staatlichem guten Willen, sondern als eines Grundrechts, das durch Verfassungs- und Gesetzesnormen garantiert wird
Efeito de concentração espermĂĄtica e perĂodo de incubação oĂłcitoespermatozĂłides na fecundação in vitro em bovinos da raça Gir
In Vitro and In Vivo Development of Horse Cloned Embryos Generated with iPSCs, Mesenchymal Stromal Cells and Fetal or Adult Fibroblasts as Nuclear Donors
The demand for equine cloning as a tool to preserve high genetic value is growing worldwide; however, nuclear transfer efficiency is still very low. To address this issue, we first evaluated the effects of time from cell fusion to activation (<1h, n = 1261; 1-2h, n = 1773; 2-3h, n = 1647) on in vitro and in vivo development of equine embryos generated by cloning. Then, we evaluated the effects of using different nuclear donor cell types in two successive experiments: I) induced pluripotent stem cells (iPSCs) vs. adult fibroblasts (AF) fused to ooplasts injected with the pluripotency-inducing genes OCT4, SOX2, MYC and KLF4, vs. AF alone as controls; II) umbilical cord-derived mesenchymal stromal cells (UC-MSCs) vs. fetal fibroblasts derived from an unborn cloned foetus (FF) vs. AF from the original individual. In the first experiment, both blastocyst production and pregnancy rates were higher in the 2-3h group (11.5% and 9.5%, respectively), respect to <1h (5.2% and 2%, respectively) and 1-2h (5.6% and 4.7%, respectively) groups (P<0.05). However, percentages of born foals/pregnancies were similar when intervals of 2-3h (35.2%) or 1-2h (35.7%) were used. In contrast to AF, the iPSCs did not generate any blastocyst-stage embryos. Moreover, injection of oocytes with the pluripotency-inducing genes did not improve blastocyst production nor pregnancy rates respect to AF controls. Finally, higher blastocyst production was obtained using UC-MSC (15.6%) than using FF (8.9%) or AF (9.3%), (P<0.05). Despite pregnancy rates were similar for these 3 groups (17.6%, 18.2% and 22%, respectively), viable foals (two) were obtained only by using FF. In summary, optimum blastocyst production rates can be obtained using a 2-3h interval between cell fusion and activation as well as using UC-MSCs as nuclear donors. Moreover, FF line can improve the efficiency of an inefficient AF line. Overall, 24 healthy foals were obtained from a total of 29 born foals
107 COMPARISON OF PRIMATE SPERM CRYOPRESERVATION PROTOCOLS: POST-THAW SPERM RECOVERY AND HYPERACTIVATION IN CULTURE
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