Production of Lambs After the Transfer of Fresh and Cryopreserved in vitro Produced Embryos from Prepubertal Lamb Oocytes and Unsorted and Sex-sorted Frozen-thawed Spermatozoa

Cumulus-oocyte complexes from hormone-stimulated 3-4-week-old (n=43) and 6-7-week-old (n=12) prepubertal lambs were matured in vitro and incubated with unsorted, or X- or Y-spermatozoa separated with a high-speed cell sorter (SX MoFlo)frozen-thawed. Presumptive zygotes were then cultured to the blastocyst stage, and transferred to recipients fresh or after cryopreservation (frozen). Oocyte cleavage was higher (p <0.05) with unsorted (515/926, 55.6%) than X- or Y-spermatozoa (261/672, 38.8% and 229/651, 35.2%, respectively) and blastocyst formation (% zygotes) by Day 9 of in vitro culture was lower (p <0.05) for X- (102/261, 39.1%) than unsorted spermatozoa (249/515, 48.3%), but did not differ between Y-spermatozoa (103/229, 45.0%) and unsorted spermatozoa, or between X- and Y-spermatozoa (p >0.05). For fresh embryos, survival to term was 50.0% (3/6) for unsorted, 0.0% (0/6) for X- and 16.7% (1/6) for Y-spermatozoa-derived embryos (p >0.05), and for frozen embryos was 4.0% (2/50) for unsorted, 9.1% (2/22) for X- and 2.9% (1/34) Y-spermatozoa-derived embryos (p >0.05). Of the two lambs born from X-spermatozoa-derived embryos, one was female (50%), and from the two Y-spermatozoa-derived lambs, both were male (100%), demonstrating that lambs can be produced after the transfer of fresh and cryopreserved IVP embryos derived from prepubertal lamb oocytes and frozen-thawed sex-sorted sperm.     

Interaction of ioxynil and mecoprop when applied to Stellaria media (L.) Vill.

The interaction of ioxynil and mecoprop applied to Stellaria media (L.) Vill. was investigated under controlled environmental conditions and several statistical methods were used to test for positive or negative interactions employing a multiplicative survival model. Information on the contribution of each herbicide to the total effect was gained by recording numbers of shoots and leaves, internode length and photosynthetic carbon dioxide exchange. Results showed that ioxynil and mecoprop can interact strongly, but the degree and direction of this interaction varied according to both the growth stage of the plants at spraying and the length of time between spraying and assessment of response. In general a synergistic interaction occurred where plants were younger at spraying and with a longer period of time between spraying and assessment of effects. These results are discussed in relation to the potential for using reduced doses of this herbicide mixture, and the importance of the design and interpretation of interaction studies are considered. Action réciproque de l'ioxynil et du MCPP appliqués sur Stellaria media (L.) Vill. L'action réciproque de l'ioxynil et du MCPP, appliqués sur Stellaria media (L.) Vill., a fait l'objet d'une étude dans des conditions ambientales contrôlées; plusieurs méthodes d'analyse statistique ont été mis en oeuvre pour déceler des actions réciproques positives ou négatives en utilisant un modèle multiplicatif de survivance. Les nombres de pousses et de feuilles, la longeur de l'entre-noeud et l'échange photosynthétique de l'acide carbonique ont été signalés pour obtenir des renseignements sur la part de chaque herbicide dans l'effet global. Les résultats ont révélé que l'ioxynil et le MCPP sont capables d'une forte action réciproque mais le niveau et le sens de cette interaction ont varié selon le stade de développement des plantes au moment de la pulvérisation ainsi que l'intervalle entre la pulvérisation et l'évaluation de la réaction. En général, une interaction synergique s'est fait voir plus les plantes étaient jeunes au moment de la pulvérisation et plus l'intervalle entre celle-ci et l'evaluation des effets était grand. Ces résultats sont discutées par rapport à la possibilité d'employer des doses réduites de cette association herbicide; on considère aussi l'importance du plan expérimental et de l'interprétation dans les études d'actions réciproques. Wechselwirkung von Ioxynil und Mecoprop auf Stellaria media (L.) Vill. Am Beispiel von Stellaria media (L.) Vill. wurde das Zusammenwirken von Ioxynil und Mecoprop unter kontrollierten Umweltbedingungen studiert. An einem multiplikativen Ueberlebensmodell wurden verschiedene statistische Methoden eingesetzt, um positive oder negative Wechselwirkungen aufzudecken. Zur Erarbeitung der notwendigen Information über den Beitrag jedes Herbizids zur Gesamtwirkung wurden folgende Parameter bestimmt: Anzahl Sprosse und Blätter, Länge der Internodien und der photosynthetische CO₂-Austausch. Die Resultate zeigten, dass Ioxynil und Mecoprop stark zusammenwirken können, wobei aber Grad und Qualität der Wechselwirkung (positiv oder negativ) je nach Alter der Pflanzen bei der Behandlung und Intervall zwischen Behandlung und Messung der Reaktion variierten. Der Trend zu Synergismus war umso ausgeprägter, je jünger die Pflanzen bei der Behandlung und je länger die Intervalle zwischen letzterer und den Messungen waren. Die Ergebnisse werden einerseits im Hinblick auf die Möglichkeit der Verwendung reduzierter Aufwandmengen dieser Herbizidmischung diskutiert, aber auch bezüglich der Wichtigkeit der Versuchsanlage zur Interpretation von Untersuchungen über Wechselwirkungen.     

Device Applications of Side-Chain Ferroelectric Liquid Crystalline Polymer Films

Side-chain ferroelectric liquid crystalline polymers are currently used in a number of applications, including displays and electrical sensors. Comparisons with existing technologies and materials indicate that relative to ceramics, such polymers have lower figures of merit but offer greater durability in sensor applications.     

Impact of Distillery Effluent on Soil Carbon and Nitrogen Dynamics in a Vertisol of Central India

Distilleries produce a huge quantity of effluents, popularly known as spent wash (SW), which when bio-methanated produce post-methanation effluents (PME). A field experiment on soybean–wheat system was conducted for five consecutive years in a Vertisol of central India to evaluate the effect of distillery effluent (DE) on soil carbon and nitrogen dynamics. Ten treatment combinations consisting of control, 100% NPK + Farmyard Manure (FYM), and graded level of SW and PME were applied. Total carbon content of soil increased significantly with applications of FYM and DE. SW was found superior in enhancing carbon content of soil in comparison to PME. Farmyard Manure contributed more carbon toward the recalcitrant pool, whereas DE contributed more carbon toward the active and slow pool. Nitrogen (N) availability was significantly improved with the application of DE. Balanced application of DE may act as amendment for increasing C and N stocks in Vertisol.     

Economic Evaluation of the Aerial Application of Cereal Herbicides1

A physical evaluation of the spray pattern achieved by a Piper Pawnee when set up to spray a cereal herbicide has been extended to include an estimation of both the biological and economic results for United Kingdom conditions. The result shows the economic importance of choosing the correct flight lane separation and the need to use a correctly set-up aircraft.     

Isolation and molecular characterisation of Neospora caninum in cattle in New Zealand

AIM: To isolate Neospora caninum from the brains of naturally infected cattle and use molecular techniques to characterise the isolates.

METHODS: Neospora caninum tachyzoites were isolated in Vero cell culture from the brains of a cow and two calves. The isolates were characterised using polymerase chain reaction (PCR) methods, DNA sequencing, an immunofluorescent anti-body test (IFAT), transmission electron microscopy (TEM), and immunohistochemistry (IHC). The brains of the three cattle were subjected to histopathological examination. A pathogenicity study was conducted in 120 BALB/c mice.

RESULTS: Neospora caninum tachyzoites were isolated from all three cases and first observed in vitro between 14 and 17 days post-inoculation. Parasites were sub-cultured and maintained in Vero cell culture for more than 6 months. PCR products were generated for all three isolates, using two different primers. Sequencing of the PCR products and a subsequent BLAST search identified the isolates as N. caninum. In addition, the isolates tested positive using IFAT and IHC, and ultrastructure revealed by TEM was characteristic of N. caninum. Histopathological examination revealed lesions characteristic of N. caninum in 1/3 brains. In the pathogenicity study using BALB/c mice, the mortality rate was 3–7%.

CONCLUSION: This was the first successful isolation of N. caninum in New Zealand confirmed using molecular characterisation tests.