Extratropical cyclone climatology across eastern Canada

Plante, Mathieu,Son, Seok‐,Woo,Atallah, Eyad,Gyakum, John,Grise, Kevin John Wiley Sons, Ltd 2015 International journal of climatology Vol.35 No.10

<P><B>ABSTRACT</B></P><P>Extratropical cyclone (ETC) tracks across eastern Canada are examined by applying a Lagrangian tracking algorithm to the lower‐tropospheric relative vorticity field of reanalysis data. Both the seasonal cycle and the interannual variability of ETCs are quantified in terms of overall cyclone frequency, intensity, and regions of development and decay. We find that ETCs travelling to eastern Canada tend to develop over the Rockies, the Great Lakes and the US East Coast. The ETCs are most intense over Newfoundland and the North Atlantic Ocean, confirming previous findings. While ETCs at cities along the Atlantic coastline (e.g. St. John's) are dominated by East Coast cyclones (which are intense in winter), those inland (e.g. Toronto) track primarily from the Great Lakes. ETCs that develop over the Gulf of Mexico affect eastern Canada infrequently, but those that do tend to be intense. The interannual variability of the wintertime ETCs is influenced by the El Niño‐Southern Oscillation (ENSO). Significant ENSO‐related variability is found over most regions of southern Canada, except on the east coast. Although ETCs at Toronto are significantly modulated by ENSO, no visible changes are found at St. John's. These ENSO‐related ETC changes are mostly due to the shifts in ETC development regions, with minor changes in the travelling direction of ETCs.</P>

Behaviors of ATP-dependent chromatin remodeling factors during maturation of bovine oocytes in vitro

Wee, Gabbine,Shin, Sang-Tae,Koo, Deog-Bon,Han, Yong-Mahn JOHN WILEY & SONS LTD 2010 MOLECULAR REPRODUCTION AND DEVELOPMENT Vol.77 No.2

<P>The mammalian oocyte undergoes dynamic changes in chromatin structure to reach complete maturation. However, little known is about behaviors of ATP-dependent chromatin remodeling factors (ACRFs) during meiosis. Here, we found that respective ACRFs may differently behave in the process of oocyte maturation in the bovine. All ACRFs interacted with oocytic chromatin at the germinal vesicle (GV) stage. Mi-2 and hSNF2H disappeared from GV-chromatin within 1 hr of in vitro culture whereas Brg-1 and BAF-170 were retained throughout germinal vesicle break down (GVBD). Brg-1 was localized on the condensed chromatin outside, whereas BAF-170 was entirely excluded from condensed chromatin. Thereafter, Brg-1 and BAF-170 interacted with metaphase I and metaphase II chromosomes. These results imply that Mi-2 and hSNF2H may initiate the meiotic resumption, and Brg-1 and BAF-170 may support chromatin condensation during meiosis. In addition, DNA methylation and methylation of histone H3 at lysine 9 (H3K9) seem to be constantly retained in the oocyte chromatin throughout in vitro maturation. Inhibition of ACRF activity by treatment with the inhibitor apyrase led to retarded chromatin remodeling in bovine oocytes, thereby resulting in poor development of fertilized embryos. Therefore, these results indicate that precise behaviors of ACRFs during meiosis are critical for nuclear maturation and subsequent embryonic development in the bovine. Mol. Reprod. Dev. 77: 126–135, 2010. © 2009 Wiley-Liss, Inc.</P>

Development and calcium level changes in pre-implantation porcine nuclear transfer embryos activated with 6-DMAP after fusion

Im, Gi-Sun,Samuel, Melissa,Lai, Liangxue,Hao, Yanhong,Prather, Randall S. JOHN WILEY & SONS LTD 2007 MOLECULAR REPRODUCTION AND DEVELOPMENT Vol.74 No.9

<P>This study investigated the effect of treatment with 6-dimethylaminopurine (6-DMAP) following fusion on in vitro development of porcine nuclear transfer (NT) embryos. Frozen thawed ear skin cells were transferred into the perivitelline space of enucleated oocytes. Reconstructed oocytes were fused and activated with electric pulse in 0.3 M mannitol supplemented with either 0.1 or 1.0 mM CaCl<SUB>2</SUB>. In each calcium concentration, activated oocytes were divided into three groups. Two groups of them were exposed to either ionomycin (I + 6-DMAP or 6-DMAP alone. In experiment 2, fused NT embryos in 0.3 M mannitol containing 1.0 mM CaCl<SUB>2</SUB> were exposed to 6-DMAP either immediately or 20 min after fusion/activation. For 0.1 mM CaCl<SUB>2</SUB>, oocytes activated with either I + 6-DMAP or 6-DMAP alone showed a higher (P < 0.05) developmental rate to the blastocyst stage than those activated with an electric pulse alone (26.7 and 22.5 vs. 12.5%). For 1.0 mM CaCl<SUB>2</SUB>, oocytes activated with either I + 6-DMAP or 6-DMAP alone showed significantly higher (P < 0.05) developmental rate to the blastocyst stage (35.6 and 28.3 vs. 19.8%). Developmental rate to the blastocyst stage was (P < 0.05) increased in NT embryos activated with 6-DMAP 20 min after fusion. 6-DMAP made a higher and wider Ca<SUP>2+</SUP> transient compared to that induced by electric pulses (Fig. 3). The fluctuation lasted during the time that oocytes were cultured in 6-DMAP. Regardless of Ca<SUP>2+</SUP> concentration in fusion medium, activation with 6-DMAP following electric pulses supported more development of porcine NT embryos. Activation of NT embryos with 6-DMAP after fusion in the presence of 1.0 mM CaCl<SUB>2</SUB> could support better developmental rate to the blastocyst stage. Mol. Reprod. Dev. 74: 1158–1164, 2007. © 2007 Wiley-Liss, Inc.</P>

Layer-by-layer AuCl3 doping of stacked graphene films

Oh, S.,Kim, B. J.,Kim, J. John Wiley Sons, Ltd 2014 Physica Status Solidi. Rapid Research Letters Vol.8 No.5

We investigated the effect of layer-by-layer AuCl3 doping on the electrical and optical properties of stacked graphene films. Graphene grown by the chemical-vapor deposition method on a Cu-foil was chemically doped by AuCl3 solution with a concentration of 20 mM. Eight different configurations were prepared and analyzed by using four-point probe measurements, optical transmittance measurements, scanning electron microscopy, and micro-Raman spectroscopy to compare the optical and electrical characteristics of the different graphene samples. In our study, the top-layer doping method was very effective because better performances considering both sheet resistance and optical transmittance were observed from the configurations with the top-layer doped. ((c) 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Establishment of an in vitro culture system for chicken preblastodermal cells

Park, Hyun Jeong,Park, Tae Sub,Kim, Tae Min,Kim, Jin Nam,Shin, Sang Su,Lim, Jeong Mook,Han, Jae Yong JOHN WILEY & SONS LTD 2006 MOLECULAR REPRODUCTION AND DEVELOPMENT Vol.73 No.4

<P>To develop an alternative source for chicken pluripotent cells, we examined (1) whether undifferentiated preblastodermal cells could be subcultured in vitro for an extended period and (2) how subculturing affected the physiological properties of preblastodermal cells. The average number of preblastodermal cells was 2,397 in stage V embryos and 36,345 in stage VII embryos; stage X embryos had an average of 53,857 blastodermal cells. The average cell size decreased significantly (70.63–18.83 µm in diameter; P < 0.0001) as the embryo grew; this was closely related to a reduction in the size and number of lipid vesicles in the cell cytoplasm. The culture conditions were optimized for the stage V preblastodermal cells and the control stage X blastodermal cells. On STO feeder cells, the preblastodermal cells achieved stable growth in vitro only in HES medium or a mixed medium of the Knockout DMEM and HES media. However, more than 10 passages of preblastodermal cells at intervals of 3–4 days was possible only by using the Knockout/HES mixed medium and BRL cell-conditioned HES medium for the primary cultures and subcultures, respectively. Colony-forming preblastodermal cells had well-delineated cytoplasm, which was positively stained for stem cell-specific markers by anti-stage-specific embryo antigen-1 antibody, periodic acid-Schiff's solution, and alkaline phosphatase. When preblastodermal cells with or without culturing were transferred into the blastodermal cavity of stage X embryos, only in vitro-cultured preblastodermal cells at stage V (4/5 = 80%) and stage VII (2/8 = 25%) induced somatic chimerism in recipient chickens. In conclusion, undifferentiated preblastodermal cells could be subcultured, and only the colony-forming preblastodermal cells that stained positively for stem cell markers could induce somatic chimerism. Mol. Reprod. Dev. © 2006 Wiley-Liss, Inc.</P>

In vitro development and cell allocation of porcine blastocysts derived by aggregation of in vitro fertilized embryos

Lee, Sang-Goo,Park, Chi-Hun,Choi, Don-Ho,Kim, Hye-Sun,Ka, Hak-Hyun,Lee, Chang-Kyu JOHN WILEY & SONS LTD 2007 MOLECULAR REPRODUCTION AND DEVELOPMENT Vol.74 No.11

<P>In pigs, the morphology and cell number of in vitro-produced blastocysts are inferior to those of their in vivo counterparts. The objective of this study was to increase developmental competence and to gain an understanding of cell allocation in blastocysts derived from the aggregation of four-cell stage porcine embryos produced in vitro. After removal of the zona pellucida, two (2×) and three (3×) four-cell stage embryos were aggregated by co-culturing them in aggregation plates. Five days after aggregation, the developmental ability and the number of cells in the aggregated embryos were determined. The percentage of blastocysts was higher (P < 0.05) in both the 2× and 3× aggregated embryos (66.6% and 72.0%, respectively) compared to that of the 1× embryos and the intact controls (43.1% and 36.4%, respectively). The total cell number of blastocysts also increased in aggregated embryos compared to that of intact controls (2.6-fold for 2× and 3.4-fold for 3×) (P < 0.05). The cells of two differentially stained embryos were started to mix at 72 hr after aggregation. In vitro-fertilized porcine aggregates (2×) were developed to blastocyst with a random distribution of cells from each embryo. The mRNA levels for the oct-4, bcl-xL and connexin 43 genes were higher (P < 0.05) and bak gene were lower (P < 0.05) in both the 2× and 3× aggregated embryos than the intact controls. Therefore, the aggregation of the four-cell stage embryos could be used to improve the quality of porcine preimplantation stage embryos produced in vitro. Mol. Reprod. Dev. 74: 1436–1445, 2007. © 2007 Wiley-Liss, Inc.</P>

Tetracycline-inducible gene expression in nuclear transfer embryos derived from porcine fetal fibroblasts transformed with retrovirus vectors

Choi, Bok Ryul,Koo, Bon Chul,Ahn, Kwang Sung,Kwon, Mo Sun,Kim, Jin-Hoi,Cho, Seong-Keun,Kim, Kyoung Mi,Kang, Jee Hyun,Shim, Hosup,Lee, Hyuna,Uhm, Sang Jun,Lee, Hoon Taek,Kim, Teoan JOHN WILEY & SONS LTD 2006 MOLECULAR REPRODUCTION AND DEVELOPMENT Vol.73 No.10

<P>A critical problem of transgenic livestock production is uncontrollable constitutive expression of the foreign gene, which usually results in serious physiological disturbances in transgenic animals. One of the best solutions for this problem may be use of controllable gene expression system. In this study, using retrovirus vectors designed to express the enhanced green fluorescent protein (EGFP) gene under the control of the tetracycline-inducible promoter, we examined whether the expression of the transgene could be controllable in fibroblast cells and nuclear transfer (NT) embryos of porcine. Transformed fibroblast cells were cultured in medium supplemented with or without doxycycline (a tetracycline analog) for 48 hr, and the induction efficiency was measured by comparing EGFP gene expression using epifluorescence microscopy and Western and Northern blot analyses. After the addition of doxycycline, EGFP expression increased up to 17-fold. The nuclei of transformed fibroblast cells were transferred into enucleated oocytes. Fluorescence emission data revealed strong EGFP gene expression in embryos cultured with doxycycline, but little or no expression in the absence of the antibiotic. Our results demonstrate the successful regulation of transgene expression in porcine nuclear transfer embryos, and support the application of an inducible expression system in transgenic pig production to solve the inherent problems of side-effects due to constitutive expression of the transgene. Mol. Reprod. Dev. © 2006 Wiley-Liss, Inc.</P>

Transcription profile in mouse four-cell, morula, and blastocyst: Genes implicated in compaction and blastocoel formation

Cui, Xiang-Shun,Li, Xing-Yu,Shen, Xing-Hui,Bae, Yong-Ju,Kang, Jason-Jongho,Kim, Nam-Hyung JOHN WILEY & SONS LTD 2007 MOLECULAR REPRODUCTION AND DEVELOPMENT Vol.74 No.2

<P>To gain insight into early embryo development, we utilized microarray technology to compare gene expression profiles in four-cell (4C), morula (MO), and blastocyst (BL) stage embryos. Differences in spot intensities were normalized, and grouped by using Avadis Prophetic software platform (version 3.3, Strand Genomics Ltd.) and categories were based on the PANTHER and gene ontology (GO) classification system. This technique identified 622 of 7,927 genes as being more highly expressed in MO when compared to 4C (P < 0.05); similarly, we identified 654 of 9,299 genes as being more highly expressed in BL than in MO (P < 0.05). Upregulation of genes for cytoskeletal, cell adhesion, and cell junction proteins were identified in the MO as compared to the 4C stage embryos, this means they could be involved in the cell compaction necessary for the development to the MO. Genes thought to be involved in ion channels, membrane traffic, transfer/carrier proteins, and lipid metabolism were also identified as being expressed at a higher level in the BL stage embryos than in the MO. Real-time RT-PCR was performed to confirm differential expression of selected genes. The identification of the genes being expressed in here will provide insight into the complex gene regulatory networks effecting compaction and blastocoel formation. Mol. Reprod. Dev. © 2006 Wiley-Liss, Inc.</P>

Feulgen reaction study of novel threadlike structures (Bonghan ducts) on the surfaces of mammalian organs

Shin, Hak-Soo,Johng, Hyeon-Min,Lee, Byung-Cheon,Cho, Sung-Il,Soh, Kyung-Soon,Baik, Ku-Youn,Yoo, Jung-Sun,Soh, Kwang-Sup JOHN WILEY & SONS LTD 2005 ANATOMICAL RECORD PART B THE NEW ANATOMIST Vol.284 No.1

<P>Threadlike structures on the surfaces of internal organs, which are thought to be part of the Bonghan duct system, were first reported about 40 years ago, but have been largely ignored since then. Recently, they were rediscovered, and in this study we discuss the Feulgen reaction that specifically stains DNA in order to identify these structures on the surface of rabbit livers as part of the Bonghan system. The distribution, shapes, and sizes of their nuclei are found to be similar to those of intravascular threadlike structures. The endothelial nuclei are rod-shaped, 10–20 μm long, and aligned in a broken-line striped fashion. The threadlike structure consists of a bundle of several subducts, which is a characteristic feature of Bonghan ducts and distinguishes them morphologically from lymphatic vessels. In addition, the Feulgen reaction clearly demonstrates that the subducts pass through a corpuscle, which is usually irregular or oval-shaped and is connected to two or several threadlike structures that form a web on the surfaces of organs. Furthermore, spherical granules of about 1 μm in diameter are detected in the subducts. These granules were well stained by using the Feulgen reaction, which implies that they contain DNA. According to previous reports, a granule is a type of microcell and plays an essential role in the physiology and therapeutic effect of the Bonghan system and acupuncture. This role has yet to be elucidated. Anat Rec (Part B: New Anat) 284B:35–40, 2005. © 2005 Wiley-Liss, Inc.</P>

Characterization of pig vasa homolog gene and specific expression in germ cell lineage

Lee, Gab Sang,Kim, Hye Soo,Lee, So Hyun,Kang, Min Soo,Kim, Dae Yong,Lee, Chang Kyu,Kang, Sung Keun,Lee, Byeong Chun,Hwang, Woo Suk JOHN WILEY & SONS LTD 2005 MOLECULAR REPRODUCTION AND DEVELOPMENT Vol.72 No.3

<P>The vasa gene is known to be an important factor for germ cell development in both invertebrates and vertebrates. In the present study, we cloned the porcine vasa homolog (Pvh, 2,172 bps) and investigated its expression at mRNA and protein levels. The isolated cDNA had deduced 724 amino acid residues with significant homology to mouse (85%) and human (91%) vasa. In adult tissues, Pvh transcript was restricted to the ovary and testis, and was undetectable in somatic tissues. During preimplantation embryo development, Pvh was transcribed in oocytes and fertilized 2-cell embryos, but not in other preimplantation embryos. In fetal stage, the transcript of Pvh gene was expressed in all fetal stage, except in day 17–18. Immunohistochemical analysis of fetal and adult gonad revealed that the Pvh protein was localized in oocytes and spermatocytes, consistent with mRNA expression. Interestingly, Pvh protein was also observed in proliferating primordial germ cells (PGCs) and freshly isolated PGCs, but not in embryonic germ cells. Our results suggest that Pvh gene can be a useful marker for germ cell development in pigs. Mol. Reprod. Dev. © 2005 Wiley-Liss, Inc.</P>