Effects of Developmental Stage, Embryonic Interferon-τ Secretion and Recipient Synchrony on Pregnancy Rate after Transfer of in vitro Produced Bovine Blastocysts

Three separate trials of bovine embryo transfers were performed consisting of 32, 41 and 33 transfers, respectively, to examine the effects of (a) the developmental stage of in vitro‐derived blastocysts, (b) the amount of interferon‐τ (IFN‐τ) they secreted during culture and (c) the cyclic stage of the recipient at the time of transfer on the probability of establishment of pregnancy. One blastocyst was transferred into the ipsilateral uterine horn to the CL. At the time of transfer, blastocysts were classified into one of three developmental stages (early blastocyst, blastocyst and expanded blastocyst) and the cyclic stage of each cow was assessed (?12 h, on time, +12 h, +24 h, >24 h). Prior to the second and third trials, blastocysts were individually cultured for 24 h in 50 μl medium droplets and the IFN‐τ concentration in the droplet was determined. Logistic regression analyses revealed that expanded blastocysts had a significantly higher likelihood of establishing pregnancy (p = 0.009), and that there was a significant interaction with the cyclic stage of the recipient in this group with lower rates of pregnancy resulting from decreasing synchrony with the recipient (p = 0.033). IFN‐τ secretion during culture was significantly higher in expanded blastocysts than in the other two groups (p < 0.05). A significant effect of the pre‐transfer level of IFN‐τ secretion was found only in the ‘Blastocyst’ group where transfer of embryos with lower IFN‐τ production prior to transfer resulted in higher pregnancy rates (p = 0.047). These results demonstrate that IFN‐τ secretion may be a useful tool to predict pregnancy outcome, but only within certain developmental stages.     

Uncommon disease symptoms caused by Fusarium oxysporum in tulips forced in the glasshouse after pre-cooling at 5°C

Rapidly developing disease symptoms not normally found in tulip bulb cultivation in The Netherlands are described. Mycelium of the fungus is present mainly in the parenchymatic tissues, giving further evidence that the fungus is not a vascular parasite in tulips. There are indications that enzymes or other compounds are involved in the syndrome. Possible factors influencing this uncommon disease development are mentioned.Samenvatting Een snelle ontwikkeling van ziektesymptomen wordt beschreven, die bij de normale teelt van tulpen in Nederland niet bekend is. Mycelium werd hoofdzakelijk aangetroffen in de parenchymatische weefsels, zowel inter- als intracellulair. Dit geeft een verdere steun aan de opvatting dat de schimmel in de tulp geen vaatparasiet is. Er bestaan aanwijzingen, dat enzymen of andere stoffen een rol spelen bij het ontstaan van dit ziektebeeld. Faktoren, die wellicht een rol spelen worden genoemd.     

Interband electronic excitation-assisted atomic-scale restructuring of metal surfaces by nanosecond pulsed laser light

Interaction of high-power laser light with materials often causes irreversible damage of the near-surface region. It is shown that copper single-crystal surfaces can be patterned by laser light. Irradiation with green light produced adatoms and vacancies, which self-organized into nanoscale pyramids. This restructuring can be removed by annealing. In contrast to green light, infrared laser irradiation at equivalent absorbed energy density did not produce any structural change. This, for metallic systems, unforeseen spectral difference in laser light action points to a concerted process as the source for structural modification, which involves long-lived primary excitation of localized d-electrons through interband transition together with phonon excitation.     

Origin of mountains on Io by thrust faulting and large-scale mass movements

Voyager stereoimages of Euboea Montes, Io, indicate that this mountain formed when a large crustal block was uplifted 10.5 kilometers and tilted by approximately 6 degrees. Uplift triggered a massive slope failure on the northwest flank, forming one of the largest debris aprons in the solar system. This slope failure probably involved relatively unconsolidated layers totaling approximately 2 kilometers in thickness, overlying a rigid crust (or lithosphere) at least 11 kilometers thick. Mountain formation on Io may involve localized deep-rooted thrust faulting and block rotation, due to compression at depth induced during vertical recycling of Io's crust.     

Triazole fungicides and the selection of resistance to medical triazoles in the opportunistic mould Aspergillus fumigatus

Azole resistance is an emerging problem in the opportunistic mould Aspergillus fumigatus. The triazoles are the most important agents for the management of Aspergillus diseases in humans. Selection for acquired resistance may occur in the hospital setting through exposure to high doses of azoles during azole therapy, but evidence is accumulating that A. fumigatus may become resistant to medical triazoles through environmental exposure to fungicides. The recovery of A. fumigatus isolates resistant to the medical triazoles from azole‐naive patients as well as from the environment strongly indicates an environmental route of resistance selection. Molecule alignment studies have identified five fungicides that share a very similar molecule structure with the medical triazoles, and thus may have selected for mechanisms that confer resistance to both groups of compounds. It is important to explore further the presumed fungicide‐driven route of resistance selection in order to implement effective preventive measures as the prevalence of azole resistance in A. fumigatus continues to increase and causes major challenges in the management of azole‐resistant Aspergillus diseases. Copyright © 2012 Society of Chemical Industry     

Arsenic mobilization in rice (Oryza sativa) and its accumulation in the grains

Flooded rice (Oryza sativa L.) may contain high arsenic (As) concentrations compared to other grain crops. For the development of measures to reduce the As concentration of rice grains, knowledge about the mobility of As within the rice plant is required. Therefore, to investigate the mobilization of As within the plant, rice was grown in nutrient solution and exposed to As either before flowering, after flowering, or continuously until maturity. Furthermore, rice was grown in four soils under greenhouse and field conditions and the time course of As accumulation in grains during the grain‐filling period was investigated. When grown in nutrient solution, As removal at flowering did not reduce As concentrations in polished rice compared to plants supplied with As continuously or after flowering. Plants that received As only after flowering had the same As concentrations in shoot and bran as plants receiving As only before flowering. However, continuous As supply resulted in doubling of As concentrations in both plant parts. In contrast to grain and shoot, the As concentration in the root decreased after As removal compared to the treatments receiving As only after flowering or continuously. The observations indicate that As was mobilized from root or shoot to the grain and that it was accumulated in the grain, although it was not available in nutrient solution during the grain‐filling period. In soil experiments, the 1000‐grain weight increased up to 2 weeks before harvest in the field as well as in the greenhouse. The As concentration in rice grain was constant during the whole grain‐filling period. It was at a similar level under field and greenhouse conditions, and its variation among soils was in the same order indicating that soil was the decisive factor for As concentration in grains. Our results suggest that temporary cultural measures during the cultivation period, for example drainage, might be ineffective because of the mobilization capacity within the rice plant. Moreover, harvest before final maturity of grains would not reduce the As concentration since it remained constant during the grain‐filling period.     

Phosphorus buffering capacity of substrate clays and its significance for plant cultivation

Peat is commonly used as the main component of horticultural substrates, but it has a very low buffering capacity for the anionic macronutrient phosphorus (P), which can be increased by the addition of clays. The aim of this study was to characterize the P adsorption capacity of different substrate clays and to evaluate its significance for plant P uptake. Substrate clays were characterized with a single‐point batch experiment and adsorption and desorption isotherms. The data were fitted to the Langmuir equation for a calculation of the maximum adsorption capacity. Additionally, the contents of oxalate extractable Fe and Al (ΣFe_ox + Al_ox) were determined. The influence of a varying P adsorption capacity of the clays on the P availability to plants in the respective peat–clay substrates and pure peat was investigated in a growth experiment with Impatiens walleriana fertigated with 0, 17, and 35 mg P L^?1 solution, respectively. The observed and calculated (Langmuir) P adsorption capacity of the clays could be well‐characterized by both the batch experiment and the adsorption isotherms and was highly correlated with the ΣFe_ox+Al_ox. A higher P adsorption capacity of the clay amendment in mixed substrates resulted in a lower P concentration in the substrate solution, while the CAT extractable P concentration (P_CAT) was the same. Plant growth and shoot P concentrations were enhanced in the substrates, showing a higher P adsorption capacity, since plants were able to take up the whole amount of P_CAT, and also part of the non‐CAT extractable P. However, the release rate was too low to ensure optimal plant growth, which was in accordance with the result of the desorption experiment. The absolute extent of P release was increased with the increasing P adsorption capacity of the clays and higher degree of P saturation (DPS).     

A contribution to the maintenance of phytopathogenic virus strains on tissue culture plantlets

Summary The long-term maintenance of phytopathogenic viruses on potato and tobacco tissue culture plantlets was investigated. Several strains of PVY^N, PVY^O, PVX, PVA, PVM, PVS and PLRV have been kept in a tissue culture type collection of viruses at the Institut für Kartoffelforschung Gross Lüsewitz for 1–3 years. The serological and biological activity of cultures established in vitro of PVY^N-D 884/Solanum tuberosum cv. Ackersegen, PVY^O-1427/Nicotiana tabacum cv. Samsun, PVX-Erstling/Nicotiana tabacum cv. Samsun and PVX-Erstling/Solanum tuberosum cv. Arkula was proved.     

Characterization of Transgenic Pigs That Express Human Decay Accelerating Factor and Cell Membrane‐tethered Human Tissue Factor Pathway Inhibitor

The expression of human complement regulatory proteins (hCRP; hDAF, hCD59, and hMCP) in pig tissues has been suggested as one of strategies to overcome the hyperacute rejection (HAR) in pig‐to‐human transplantation. Expression of human tissue factor pathway inhibitor (hTFPI) in porcine endothelial cells has been suggested as a remedy to overcome microvascular thrombosis. To investigate the effects of these combined transgenes, we established transformed pig cells expressing human decay accelerating factor (hDAF) under the control of enhancer promoter (5′LTR‐PCMVIE), and the fusion protein (hTFPI/hCD4) consisting of the functional domains (K1 and K2) of hTFPI and membrane‐tethering domains (D3 and D4) of hCD4 under the control of PCMVIE. Transgenic pigs were generated with the transformed porcine cells through somatic cell nuclear transfer (SCNT) technology. Analysis of quantitative PCR and real‐time quantitative RT‐PCR showed that four copies of hDAF were integrated and 391 copies of hDAF mRNA expressed in the cells of the transgenic pig. The enhancing activity of 5′LTR was approximately 2 fold compared to CMVIE promoter only. The cell viability test showed that more than 80% of ear cells were viable in the presence of 50% human serum. The chromogenic substrate assay and immunocytochemical staining with tail cells showed that the TFPI activity of fusion protein was observed on the cell membrane. The membrane localization of hDAF and hTFPI proteins was observed by immunocytochemical staining, and the expression of transgenes in heart and liver tissues was also confirmed by immunohistochemistry.