40 research outputs found

    Strategic corporate communication in the digital age

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    This chapter presents a systematic review of over thirty (30) types of online marketing methods. It describes different methods like email marketing, social network marketing, in-game marketing and augmented reality marketing, among other approaches. The researchers discuss that the rationale for using these online marketing strategies is to increase brand awareness, customer centric marketing and consumer loyalty. They shed light on various personalization methods including recommendation systems and user generated content in their taxonomy of online marketing terms. Hence, they explain how these online marketing methods are related to each other. The researchers contend that the boundaries between online marketing methods have not been clarified enough within the academic literature. Therefore, this chapter provides a better understanding of different online marketing methods. A review of the literature suggests that the ‘oldest’ online marketing methods including the email and the websites are still very relevant for today’s corporate communication. In conclusion, the researchers put forward their recommendations for future research about contemporary online marketing methods.peer-reviewe

    Effects of exposure to dmso in vitrification solution on cytotoxicity and in vitro viability of immature bovine oocyte.

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    Based on previous studies for vitrification of oocytes, it has been shown that short term exposure to DMSO during vitrification could improve the maturation rate and cause not spontaneous parthenogenesis (Isachenko et al., 2006). In addition, it was reported that DMSO in freezing media caused disassembly of microfilaments and chromosomal abnormalities in mouse oocytes (Vincent et al., 1990). On the other hand, DMSO is categorized as a potent glass former and its existence in vitrification solution seems necessary. The aim of this study was to determine the in vitro viability of immature bovine oocytes vitrified by short or long time exposure to DMSO. Materials and Methods: Cumulus oocytes complexes (COCs) with homogenous ooplasm were recovered from slaughterhouse ovaries and used in this study. The vitrification protocol was adapted from Kuwayama et al (2005) with minor modifications. Briefly, oocytes were washed twice in holding solution (HS, Hepes-buffered TCM medium supplemented with 20% fetal calf serum, FCS) and kept there for about 15 min. Group of four COCs were incubated in the first vitrification solution (VS1; 7.5% DMSO and 7.5% EG in HS) for 12 min. Equilibration in VS1 was performed in three steps of increasing concentration. First (F) and second (S) steps contained 1/3 and 2/3 of VS1 diluted in HS, and the third (T) step contained only pure VS1. Based on removal of DMSO from each step, five treatment groups were designed: (G1) control, (G2) VS1, (G3) F w/o DMSO, (G4) F+S w/o DMSO, and (G5) F+S+T w/o DMSO. For G3, G4 and G5, similar concentration of EG was added to replace DMSO in VS1. All treatment groups were equilibrated into the second vitrification solution (VS2; 15% DMSO, 15% EG and 0.5M sucrose in HS) for a further 60 sec. Two experiments were performed: (a) cytotoxicity after only exposure, and (b) in vitro viability after vitrification processes. In cytotoxicity test, immature oocytes were directly transferred to the warming solution (WS). In vitrification experiment, oocytes were instantly loaded on a Cryotop device and submerged into liquid nitrogen (LN2) for storage. The time of exposure from VS2 to LN2 was not longer than 90 s. Vitrified samples were maintained in LN2 for at least 10 days. Immediately after removing the Cryotop from LN2, thin strip of Cryotop was submerged in 3 ml HS plus 1M sucrose (WS; 39°C) and smoothly tried to detach oocytes from Cryotop device. Immature oocytes were left in WS for one minute and then transferred to HS plus 0.5M and 0.15M sucrose solution for 3 and 5 min, respectively. Finally, the immature oocytes were washed twice in HS for 5 min each and processed for in vitro maturation. Significant differences among treatments used in the experiment were revealed by one-way analysis of variance and followed by Duncan's multiple range test for mean comparisons (P < 0.05) using SAS software (ver. 9.1)

    Structural changes in cattle immature oocytes subjected to slow freezing and vitrification.

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    This study was conducted to evaluate the effect of different cryopreservation methods (slow-freezing and vitrification) on structural changes of bovine immature oocytes. Bovine ovaries were collected from local abattoirs. Cumulus-oocytecomplexes (COCs) were retrieved using aspiration method from 2-6 mm follicles. In Experiment 1, selected oocytes were randomly divided into 4 treatment groups namely freezing solution-exposed, frozen-thawed, vitrification solution-exposed and vitrified-thawed and then oocytes abnormalities were examined under a stereomicroscope. In Experiment 2, oocytes were randomly allocated to the same grouping as experiment 1 plus control group. Following freezing or vitrification, all oocytes were fixed in glutaraldehyde and processed for transmission electron microscopy. In experiment 1, there was a higher incidence of abnormalities in the frozen-thawed and vitrified-warmed oocytes compared to those in freezing solution and vitrification solution-exposed groups (P <0.05). In experiment 2, there were marked alterations in the perivitelline space, microvilli and vesicles of frozenthawed and vitrified-warmed oocytescharacterized by loss of elasticity and integrity of cytoplasmic processes and microvilli following cooling and warming. In conclusion, ethylene glycol-based freezingand vitrification solutions are suitable choices for cryopreservation of immature oocytes and most organelles are able to retain their normal morphology followingcryopreservation and thawing processe

    An online intelligent robust adaptive LSQR estimation method for LTI state space model

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    Abstract Regarding the low accuracy and instability of common online methods for estimating dynamic models in the time domain, in the presence of uncertainty in system dynamics, sensor noise and environmental disturbances, this area is still open for further research. In this paper, a new estimation method is proposed based on a new online robust meta‐heuristic adaptive LSQR (ORALSQR) for simultaneous estimation of a multi input/output linear dynamic model and system state variables. This new adaptive LSQR algorithm is used to solve the output matrix equations of the least squares error problem. The presented algorithm, based on its iterative nature, searches the answer subspace by using a new meta‐heuristic logic. In addition, the algorithm solving steps and the search domain size in each iteration are intelligently determined by the method. In an identification maneuver, this method estimates the state variables using an estimated model in the Kalman filter, then estimates the model online for the next iteration using the state variables. In addition the stability proof of this method is presented. Numerical results show more accuracy and robustness of this method compared to the other methods mentioned in this paper which contain LS and RLS based estimation methods
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