867 resultados para Fragmented oocytes


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Mesenchymal stem cells (MSCs) have been reported to secrete a variety of cytokines and growth factors acting as trophic suppliers, but little is known regarding the effects of conditioned medium (CM) of MSCs isolated from femurs and tibias of mouse on the artificial activation of mouse oocytes and on the developmental competence of the parthenotes. In the current study, we investigated the effect of CM on the events of mouse oocyte activation, namely oscillations of cytosolic calcium concentration ([Ca²+]i), meiosis resumption, pronucleus formation, and parthenogenetic development. The surface markers of MSCs were identified with a fluorescence-activated cell sorter. The dynamic changes of the spindle and formation of pronuclei were examined by laser-scanning confocal microscopy. Exposure of cumulus-oocyte complexes to CM for 40 min was optimal for inducing oocyte parthenogenetic activation and evoking [Ca²+]i oscillations similar to those evoked by sperm (95 vs 100%; P > 0.05). Parthenogenetically activated oocytes immediately treated with 7.5 µg/mL cytochalasin B (CB), which inhibited spindle rotation and second polar body extrusion, were mostly diploid (93 vs 6%, P < 0.01) while CB-untreated oocytes were mostly haploid (5 vs 83%, P < 0.01). Consequently, the blastocyst rate was higher in the CB-treated than in the CB-untreated oocytes. There was no significant difference in developmental rate between oocytes activated with CM and 7% ethanol (62 vs 62%, P > 0.05), but the developmental competence of the fertilized oocytes was superior to that of the parthenotes (88 vs 62%, P < 0.05). The present results demonstrate that CM can effectively activate mouse oocytes, as judged by the generation of [Ca²+]i oscillations, completion of meiosis and parthenogenetic development.

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Currents mediated by calcium-activated chloride channels (CaCCs), observed for the first time in Xenopus oocytes, have been recorded in many cells and tissues ranging from different types of neurons to epithelial and muscle cells. CaCCs play a role in the regulation of excitability in neurons including sensory receptors. In addition, they are crucial mediators of chloride movements in epithelial cells where their activity regulates electrolyte and fluid transport. The roles of CaCCs, particularly in epithelia, are briefly reviewed with emphasis on their function in secretory epithelia. The recent identification by three independent groups, using different strategies, of TMEM16A as the molecular counterpart of the CaCC is discussed. TMEM16A is part of a family that has 10 other members in mice. The discovery of the potential TMEM16 anion channel activity opens the way for the molecular investigation of the role of these anion channels in specific cells and in organ physiology and pathophysiology. The identification of TMEM16A protein as a CaCC chloride channel molecule represents a great triumph of scientific perseverance and ingenuity. The varied approaches used by the three independent research groups also augur well for the solidity of the discovery.

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Impaired cholinergic neurotransmission can affect memory formation and influence sleep-wake cycles (SWC). In the present study, we describe the SWC in mice with a deficient vesicular acetylcholine transporter (VAChT) system, previously characterized as presenting reduced acetylcholine release and cognitive and behavioral dysfunctions. Continuous, chronic ECoG and EMG recordings were used to evaluate the SWC pattern during light and dark phases in VAChT knockdown heterozygous (VAChT-KDHET, n=7) and wild-type (WT, n=7) mice. SWC were evaluated for sleep efficiency, total amount and mean duration of slow-wave, intermediate and paradoxical sleep, as well as the number of awakenings from sleep. After recording SWC, contextual fear-conditioning tests were used as an acetylcholine-dependent learning paradigm. The results showed that sleep efficiency in VAChT-KDHET animals was similar to that of WT mice, but that the SWC was more fragmented. Fragmentation was characterized by an increase in the number of awakenings, mainly during intermediate sleep. VAChT-KDHET animals performed poorly in the contextual fear-conditioning paradigm (mean freezing time: 34.4±3.1 and 44.5±3.3 s for WT and VAChT-KDHET animals, respectively), which was followed by a 45% reduction in the number of paradoxical sleep episodes after the training session. Taken together, the results show that reduced cholinergic transmission led to sleep fragmentation and learning impairment. We discuss the results on the basis of cholinergic plasticity and its relevance to sleep homeostasis. We suggest that VAChT-KDHET mice could be a useful model to test cholinergic drugs used to treat sleep dysfunction in neurodegenerative disorders.

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It has been shown that cytokines can act as molecular adjuvant to enhance the immune response induced by DNA vaccines, but it is unknown whether interleukin 33 (IL-33) can enhance the immunocontraceptive effect induced by DNA vaccines. In the present study, we explored the effects of murine IL-33 on infertility induced by Lagurus lagurus zona pellucida 3 (Lzp3) contraceptive DNA vaccine administered by the mucosal route. Plasmid pcD-Lzp3 and plasmid pcD-mIL-33 were encapsulated with chitosan to generate the nanoparticle chi-(pcD-Lzp3+pcD-mIL-33) as the DNA vaccine. Sixty female ICR mice, divided into 5 groups (n=12/group), were intranasally immunized on days 0, 14, 28, and 42. After intranasal immunization, the anti-LZP3-specific IgG in serum and IgA in vaginal secretions and feces were determined by ELISA. The results showed that chi-(pcD-Lzp3+pcD-mIL-33) co-immunization induced the highest levels of serum IgG, secreted mucosal IgA, and T cell proliferation. Importantly, mice co-immunized with chi-(pcD-Lzp3+pcD-mIL-33) had the lowest birth rate and mean litter size, which correlated with high levels of antibodies. Ovaries from infertile female mice co-immunized with chi-(pcD-Lzp3+pcD-mIL-33) showed abnormal development of ovarian follicles, indicated by atretic follicles and loss of oocytes. Our results demonstrated that intranasal delivery of the molecular adjuvant mIL-33 with chi-pcD-Lzp3significantly increased infertility by enhancing both systemic and mucosal immune responses. Therefore, chi-(pcD-Lzp3+pcD-mIL-33) co-immunization could be a strategy for controlling the population of wild animal pests.

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This study reports a case of a gonadotropin-releasing hormone agonist trigger in a young female with myelodysplastic syndrome (MDS) who underwent fertility preservation using random-start controlled ovarian stimulation. This method involves the stimulation of the ovary regardless of a patient's menstrual-cycle phase. A review of the related literature is also provided. A 17-year-old patient was diagnosed with MDS and required initiation of peripheral blood stem cell transplantation within a maximum of 3 weeks and was in the luteal phase of the menstrual cycle when the possibility of attempting preservation of fertility was presented to her. She opted for a random-start controlled ovarian stimulation with gonadotropins. With successful hemorrhagic prophylaxis, 17 oocytes were retrieved including 10 mature and 7 immature oocytes. Of the immature oocytes, 3 were successfully matured in vitro and a vitrification protocol was used to freeze the 13 mature oocytes.

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Sleep is important for the recovery of a critically ill patient, as lack of sleep is known to influence negatively a person’s cardiovascular system, mood, orientation, and metabolic and immune function and thus, it may prolong patients’ intensive care unit (ICU) and hospital stay. Intubated and mechanically ventilated patients suffer from fragmented and light sleep. However, it is not known well how non-intubated patients sleep. The evaluation of the patients’ sleep may be compromised by their fatigue and still position with no indication if they are asleep or not. The purpose of this study was to evaluate ICU patients’ sleep evaluation methods, the quality of non-intubated patients’ sleep, and the sleep evaluations performed by ICU nurses. The aims were to develop recommendations of patients’ sleep evaluation for ICU nurses and to provide a description of the quality of non-intubated patients’ sleep. The literature review of ICU patients’ sleep evaluation methods was extended to the end of 2014. The evaluation of the quality of patients’ sleep was conducted with four data: A) the nurses’ narrative documentations of the quality of patients’ sleep (n=114), B) the nurses’ sleep evaluations (n=21) with a structured observation instrument C) the patients’ self-evaluations (n=114) with the Richards-Campbell Sleep Questionnaire, and D) polysomnographic evaluations of the quality of patients’ sleep (n=21). The correspondence of data A with data C (collected 4–8/2011), and data B with data D (collected 5–8/2009) were analysed. Content analysis was used for the nurses’ documentations and statistical analyses for all the other data. The quality of non-intubated patients’ sleep varied between individuals. In many patients, sleep was light, awakenings were frequent, and the amount of sleep was insufficient as compared to sleep in healthy people. However, some patients were able to sleep well. The patients evaluated the quality of their sleep on average neither high nor low. Sleep depth was evaluated to be the worst and the speed of falling asleep the best aspect of sleep, on a scale 0 (poor sleep) to 100 (good sleep). Nursing care was mostly performed while the patients were awake, and thus the disturbing effect was low. The instruments available for nurses to evaluate the quality of patients’ sleep were limited and measured mainly the quantity of sleep. Nurses’ structured observatory evaluations of the quality of patients’ sleep were correct for approximately two thirds of the cases, and only regarding total sleep time. Nurses’ narrative documentations of the patients’ sleep corresponded with patients’ self-evaluations in just over half of the cases. However, nurses documented several dimensions of sleep that are not included in the present sleep evaluation instruments. They could be classified according to the components of the nursing process: needs assessment, sleep assessment, intervention, and effect of intervention. Valid, more comprehensive sleep evaluation methods for nurses are needed to evaluate, document, improve and study patients’ quality of sleep.

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This master’s thesis studies the case company’s current purchase invoice process and the challenges that are related to it. Like most of other master’s thesis this study consists of both theoretical- and empirical parts. The purpose of this work is to combine theoretical and empirical parts together so that the theoretical part brings value to the empirical case study. The case company’s main business is frequency converters for both low voltage AC & DC drives and medium voltage AC Drives which are used across all industries and applications. The main focus of this study is on the current invoice process modelling. When modelling the existing process with discipline and care, current challenges can be understood better. Empirical study relays heavily on interviews and existing, yet fragmented, data. This, along with own calculations and analysis, creates the foundation for the empirical part of this master’s thesis.

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This master’s thesis was made in order to gain answers to the question of how the integration of the marketing communications and the decision making related to it in a geographically dispersed service organization could be improved in a situation where an organization has gone through a merger. The effects of the organizational design dimensions towards the integration of the marketing communications and the decision making related to it was the main focus. A case study as a research strategy offered a perfect frames for an exploratory study and the data collection was conducted by semi-structured interviews and observing. The main finding proved that from the chosen design dimensions, decentralization, coordination and power, could be found specific factors that in a geographically dispersed organization are affecting the integration of the marketing communications negatively. The effects can be seen mostly in the decision making processes, roles and in the division of responsibility, which are affecting the other dimensions and by this, the integration. In a post-merger situation, the coordination dimension and especially the information asymmetry and the information flow seem to have a largest affect towards the integration of the marketing communications. An asymmetric information distribution with the lack of business and marketing education resulted in low self-assurance and at the end in fragmented management and to the inability to set targets and make independent decisions. As conclusions it can be stated, that with the organizational design dimensions can the effects of a merger towards the integration process of the marketing communications to be evaluated.

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This thesis addresses the coolability of porous debris beds in the context of severe accident management of nuclear power reactors. In a hypothetical severe accident at a Nordic-type boiling water reactor, the lower drywell of the containment is flooded, for the purpose of cooling the core melt discharged from the reactor pressure vessel in a water pool. The melt is fragmented and solidified in the pool, ultimately forming a porous debris bed that generates decay heat. The properties of the bed determine the limiting value for the heat flux that can be removed from the debris to the surrounding water without the risk of re-melting. The coolability of porous debris beds has been investigated experimentally by measuring the dryout power in electrically heated test beds that have different geometries. The geometries represent the debris bed shapes that may form in an accident scenario. The focus is especially on heap-like, realistic geometries which facilitate the multi-dimensional infiltration (flooding) of coolant into the bed. Spherical and irregular particles have been used to simulate the debris. The experiments have been modeled using 2D and 3D simulation codes applicable to fluid flow and heat transfer in porous media. Based on the experimental and simulation results, an interpretation of the dryout behavior in complex debris bed geometries is presented, and the validity of the codes and models for dryout predictions is evaluated. According to the experimental and simulation results, the coolability of the debris bed depends on both the flooding mode and the height of the bed. In the experiments, it was found that multi-dimensional flooding increases the dryout heat flux and coolability in a heap-shaped debris bed by 47–58% compared to the dryout heat flux of a classical, top-flooded bed of the same height. However, heap-like beds are higher than flat, top-flooded beds, which results in the formation of larger steam flux at the top of the bed. This counteracts the effect of the multi-dimensional flooding. Based on the measured dryout heat fluxes, the maximum height of a heap-like bed can only be about 1.5 times the height of a top-flooded, cylindrical bed in order to preserve the direct benefit from the multi-dimensional flooding. In addition, studies were conducted to evaluate the hydrodynamically representative effective particle diameter, which is applied in simulation models to describe debris beds that consist of irregular particles with considerable size variation. The results suggest that the effective diameter is small, closest to the mean diameter based on the number or length of particles.

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This thesis studies the collective memory of the Russian-speaking minority living in Estonia. The minority is exposed to two national narratives regarding the incorporation of Estonia into the Soviet Union in 1940. According to the Estonian narrative, Estonia was occupied and annexed by the Soviet Union while the Soviet-Russian narrative sees the actions to have been legal and voluntary. This thesis firstly examines thoughts the existence of these two opposing narratives evoke among the Russian-speaking minority and secondly it explores whether the views of the minority compare with the two official yet divergent narratives. The study focuses on the second and third generation minority members. The topic belongs to the field of memory studies. The objective is to understand the views the Russian minority have towards the controversial events of the years 1939-40. To accomplish the objectives set, a web-based survey using open-ended and multiple-choice questions was conducted. The open-ended questions addressed the main research questions while the multiple-choice questions contributed to forming a more comprehensive understanding of the subject in question. In order to interpret the data, qualitative content analysis has been applied. Based on the findings, the Russian-speaking minority respondents’ understanding of the events of 1939-40 could be described as fragmented, inconsistent and including viewpoints that resulted from the merger of different storylines. There is no single cohesive or coherent narrative of the past amongst the minority. In addition to that, their views do not generally comply with the narrative of the Russian Federation as often referred to in literature, even though the minority respondents do not want to see the Soviet involvement as critically as the Estonian narrative does. Many respondents conceive the events of 1939-40 as ambiguous revealing the ability to be tolerant and receptive in their views regarding the past.

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This paper aims at reconciling the evidence that sophisticated valuation models are increasingly used by companies in their investment appraisal with the literature of bounded rationality, according to which objective optimization is impracticable in the real world because it would demand an immense level of sophistication of the analytical and computational processes of human beings. We show how normative valuation models should rather be viewed as forms of reality representation, frameworks according to which the real world is perceived, fragmented for a better understanding, and recomposed, providing an orderly method for undertaking a task as complex as the investment decision.

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The Finnish legislation requires for a safe and secure learning environment. However, the comprehensive, risk based safety and security management (SSM) and the management commitment in the implementation and development of the SSM are not mentioned in the legislation. Multiple institutions, operators and researchers have studied and developed safety and security in educational institutions over the past decade. Typically the approach has been fragmented and without bringing up the importance of the comprehensive SSM. The development needs of the safety and security operations in universities have been studied. However, in universities of applied sciences (UASs) and in elementary schools (ESs), the performance level, strengths and weaknesses of the comprehensive SSM have not been studied. The objective of this study was to develop the comprehensive, risk based SSM of educational institutions by developing the new Asteri consultative auditing process and study its effects on auditees. Furthermore, the performance level in the comprehensive SSM in UASs and ESs were studied using Asteri and the TUTOR model developed by the Keski-Uusimaa Department for Rescue Services. In addition, strengths, development needs and differences were identified. In total, 76 educational institutions were audited between the years 2011 and 2014. The study is based on logical empiricism, and an observational applied research design was used. Auditing, observation and an electronic survey were used for data collection. Statistical analysis was used to analyze the collected information. In addition, thematic analysis was used to analyze the development areas of the organizations mentioned by the respondents in the survey. As one of the main contributions, this research presents the new Asteri consultative auditing process. Organizations with low performance levels on the audited subject benefit the most from the Asteri consultative auditing process. Asteri may be usable in many different types of audits, not only in SSM audits. As a new result, this study provides new knowledge on attitudes related to auditing. According to the research findings, auditing may generate negative attitudes and the auditor should take them into account when planning and preparing for audits. Negative attitudes can be compensated by producing added value, objectivity and positivity for the audit and, thus, improve the positive effects of auditing on knowledge and skills. Moreover, as the results of this study shows, auditing safety and security issues do not increase feelings of insecurity, but rather increase feelings of safety and security when using the new Asteri consultative auditing process with the TUTOR model. The results showed that the SSM in the audited UASs was statistically significantly more advanced than that in the audited ESs. However, there is still room for improvement in the ESs and the UASs as the approach to the SSM was fragmented. It can be assumed that the majority of Finnish UASs and ESs do not likely meet the basic level of the comprehensive, risk based the SSM.

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Innovation remains one of the key drivers of sustainable and successful business. The variety of innovation approaches such as open models, intersectional thinking and co-creation tackles the challenge of viable novel offerings across the world. These approaches have certain similarities and their elements constitute design thinking. Recent market and society trends such as technological advances and globalization have intensify companies’ interaction with customers. Emotional engagement, pleasing communication and delight have gained equal to functionality importance. The complex of these components constitutes consumer experience. Academic research conceptualizes these changes by introducing customer-centered innovation, which replaces product-oriented approaches. However, both methods omit experience concept and provide fragmented explanation of experience innovation. Experience is an essential process of offering perception, which drives customer decisions. Therefore, an agenda of experience innovation development can systemize and explain the mechanisms of experience innovation. The purpose of this study is to create and explain the stage process framework of experience innovation by the means of design thinking approach. The research proceeds in accordance with the following sub-objectives: 1. Conceptualization of consumer experience through customer value. 2. Creation of experience innovation framework by the means of design thinking. This study is conducted by the means of conceptual research methods. The main theoretical contribution of the study is creation of the integrated framework of consumer experience innovation. The elaboration of design thinking agenda and methods applied to experience design builds the guidelines of experience innovation development. This research synthesizes the conceptual elements of the framework that resolves inconsistencies and duplications of theories. This essential clarification simplifies application of the experience innovation agenda, which can be useful for the wide range of specialists, from marketing to strategists, and from managers to entrepreneurs, willing to offer compelling experience to customers. The study highlights the crucial role of consumer experience in maintaining customer loyalty and designs the roadmap of innovating experience through the communication with customers.

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Our surrounding landscape is in a constantly dynamic state, but recently the rate of changes and their effects on the environment have considerably increased. In terms of the impact on nature, this development has not been entirely positive, but has rather caused a decline in valuable species, habitats, and general biodiversity. Regardless of recognizing the problem and its high importance, plans and actions of how to stop the detrimental development are largely lacking. This partly originates from a lack of genuine will, but is also due to difficulties in detecting many valuable landscape components and their consequent neglect. To support knowledge extraction, various digital environmental data sources may be of substantial help, but only if all the relevant background factors are known and the data is processed in a suitable way. This dissertation concentrates on detecting ecologically valuable landscape components by using geospatial data sources, and applies this knowledge to support spatial planning and management activities. In other words, the focus is on observing regionally valuable species, habitats, and biotopes with GIS and remote sensing data, using suitable methods for their analysis. Primary emphasis is given to the hemiboreal vegetation zone and the drastic decline in its semi-natural grasslands, which were created by a long trajectory of traditional grazing and management activities. However, the applied perspective is largely methodological, and allows for the application of the obtained results in various contexts. Models based on statistical dependencies and correlations of multiple variables, which are able to extract desired properties from a large mass of initial data, are emphasized in the dissertation. In addition, the papers included combine several data sets from different sources and dates together, with the aim of detecting a wider range of environmental characteristics, as well as pointing out their temporal dynamics. The results of the dissertation emphasise the multidimensionality and dynamics of landscapes, which need to be understood in order to be able to recognise their ecologically valuable components. This not only requires knowledge about the emergence of these components and an understanding of the used data, but also the need to focus the observations on minute details that are able to indicate the existence of fragmented and partly overlapping landscape targets. In addition, this pinpoints the fact that most of the existing classifications are too generalised as such to provide all the required details, but they can be utilized at various steps along a longer processing chain. The dissertation also emphases the importance of landscape history as an important factor, which both creates and preserves ecological values, and which sets an essential standpoint for understanding the present landscape characteristics. The obtained results are significant both in terms of preserving semi-natural grasslands, as well as general methodological development, giving support to science-based framework in order to evaluate ecological values and guide spatial planning.

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The objective of this investigation was to clarify the adaptive significance of female sexual behaviours in the house cricket, Acheta domesticus, and the Texas field cricket, Gryllus integer. Experiments were focussed primarily on: nutritional factors affecting female reproductive success; the ontogeny of female sexual behaviours; female mating frequency and progeny production; and the pattern of sperm competition. Reproduction of singly mated female A. domesticus assigned to 3 nutritional regimes was compared . Females fed a vitamin and protein-enriched mouse chow, cannibalistic females, and starved females produced on the average, 513 , 200 and 68 offspring, respectively. Cannibals probably could not obtain the same amounts of essential nutrients as females fed mouse chow. Reabsorption of oocytes was likely the major factor contributing to the decreased reproduction of starved females. In addition, female !. domesticus fed mouse chow, but allowed constant access to males produced 11 times as many offspring than did females fed corn meal. Females fed corn meal probably could not absorb or synthesize enough dietary lipids, thus resulting in poor ovariole growth. Female !. domesticus first mate at an average adult age of 7 days, closely corresponding to when they first exhibit positive phonotaxis. Females mate repeatedly and often consume the externally attached spermatophore. In ~. domesticus, females allowed constant access to males produced significantly more offspring than did single maters. Similarly, doubly mated G. integer females produced more offspring than did single maters. This difference resulted largely from the failure of many single maters to reproduce. Remating by female crickets partly functions in offsetting the possibility of a failed initial mating. Nymph production increased significantly with the time the spermatophore was attached in singly mated ~. domesticus. Spermatophore consumption by the female was not affected by male guarding behaviour, and the interval between mating and eating of the spermatophore may often be shorter than the time required for maximum insemination. Some degree of sperm depletion in singly mated !. domesticus and G. integer may have occurred. The patterns of daily offspring production of singly and multiplymated females suggests that a factor provided by a male during mating stimulates female oviposition and/or egg production. Female crickets also might acquire nutrition from spermatophore consumption, a benefit that is augmented by female multiple mating. The electrophoretic examination of various allozymes in ~. integer did not permit determination of a pattern of sperm competition. However, the possibility of last male sperm predominance is related to male guarding behaviour.