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Certain aspects in the collection, handling, storage, and subsequent analysis of discrete air samples from non-steady-state flux chambers are critical to generating accurate and unbiased estimates of nitrous oxide (N

Plasma thyroxine (T4) concentrations and seawater tolerance were measured in one-year-old (SI) and two-year-old (S2) Atlantic salmon (Salmo salar L.) smolts and S2 sea trout (Salmo trutta L.) smolts reared under natural temperature and photoperiod regimes in western Ireland (09?34/W 53?55/N). The S2 salmon and sea trout showed significant surges in T4 titres during April-May, which coincided approximately with the period of maximum seawater tolerance. However, no T4 surges were observed in SI salmon during the sampling period (February?June). Nevertheless, SI salmon exhibited a clear increase in seawater tolerance, indicating that they can complete smoltification without an observed elevation in T4 titres. The seawater tolerance of S2 sea trout progressively increased during the smolt period. The results demonstrate clear differences in seawater tolerance and the development of smoltification between sea trout and salmon. D.T.G. Quigley (corresponding author; e-mail: declanquigley? eircom.net), Carrigadrohid Smolts Ltd, Macroom, Co. Cork; M.J. Harvey, Martin Ryan Institute, Cama Research Laboratories, Cama, Co. Galway; T.J. Hayden and C. Dowling, Department of Zoology, University College Dublin, Belfield, Dublin 4; M.P. O'Keane

Twenty-eight bitches with unknown reproductive histories were injected intravenously with either human chorionic gonadotrophin (hCG) or equine chorionic gonadotrophin (eCG) (pregnant mare's serum gonadotrophin) and their oestradiol responses were measured at the time of the injection and 90 minutes later. They were at various stages of the oestrous cycle as determined by histology and a progesterone assay for luteal function. Twenty-six of them were considered to be entire because they showed either an increase in plasma oestradiol over preinjection values or steady high values. The ovaries were removed from 25 of these animals and the other probably had a remnant of ovary because it came into oestrus some weeks later. In two remaining bitches no oestradiol could be detected either before or after the injection of gonadotrophin and they were predicted to have been neutered, which was confirmed at laparotomy. In the entire bitches, the highest plasma oestradiol concentration was measured during metoestrus and the lowest during anoestrus.

Thirty-two permanently pseudopregnant bitches were treated with the anti-prolactin drug cabergoline. They had all been ovariohysterectomised up to five months after their last season, in some cases over two years previously, when most were reported as showing no signs of the condition. The clinical signs were mainly behavioural, the majority being aggressive, and a small number were lactating. The efficiency of the cabergoline therapy was classified by the owners as 'excellent' or 'good' in 50 per cent of the cases, and fair in 36 per cent. The rate of success was markedly better than in similar cases treated with reproductive steroids. In all but one of the bitches, the plasma prolactin concentrations were basal.

Extension of basement below significant detachment layers such as salt results in the formation of structures in the cover strata above the detachment layer in two ways. ‘Thick-skinned’ cover structures evolve to balance basement stretching. These are linked to the basement faults via detachment in the salt layer, or are directly linked to the basement structure, depending on the amount of basement fault displacement relative to salt layer thickness. Basement extension also results in rotation of major basement fault blocks, tilting the detachment layer and precipitating gravity-driven, ‘thin-skinned’ slip of the cover involving detached extensional faulting and folding. Detachment layers consisting specifically of salt play two roles in facilitating the development of thin-skinned systems: salt constitutes the detachment layer and also lends buoyancy to the cores of anticlinal folds, reducing resistance to shortening. The detachment layer may become tilted away from the basement fault scarp, resulting in ‘synthetic slip systems’ with the same polarity as the underlying basement fault, or the detachment may be tilted toward the basement scarp, giving ‘antithetic slip systems’, of the opposite polarity. In both cases the slides may terminate downdip in detachment folds and/or reverse faults. Both types of thin-skinned system will interact with those cover structures directly balancing basement extension and all of these components must be considered during section restoration. Tilt associated with 3D basement fault geometry (e.g. relay zones) may result in decoupled cover faults locally trending at high angles to the trend of underlying basement faults. Contrasting strain rates of basement faulting and related cover slip can lead to continuation of cover structural evolution after cessation of basement extension, giving for example cover faults and folds of Lower Cretaceous age in the Central North Sea, though basement extension had occurred in the Upper Jurassic. Synthetic systems may include footwall-derived olistostromes emplaced above basement hangingwalls—these commonly occur above basement relay ramps on segmented basin margins. Examples from the Central Graben and Channel Basin are discussed. Examples of antithetic systems from the Irish Sea, Central Graben and a field example from the Bristol Channel Basin are discussed.

A potent anti-prolactin drug, cabergoline, administered orally for five days, was clinically successful in treating three different clinical manifestations of pseudopregnancy in referred bitches. The clinical conditions treated were categorised as standard pseudopregnant bitches (n = 8), those previously unsuccessfully treated with hormones (n = 10) and those which had behavioural pseudopregnancy following ovariohysterectomy (n = 8). The number of bitches whose owners reported a 'good' response was seven out of eight, six out of 10 and six out of eight, respectively. There were very few side effects in that only one bitch vomited following treatment. The clinical response did not necessarily appear to be related to an alteration in circulating prolactin concentrations, suggesting that the drug may have a direct effect on the tissues as well as in most cases reducing the plasma prolactin concentrations.

Methodologies are required to verify agricultural greenhouse gas mitigation at scales relevant to farm management. Micrometeorological techniques provide a viable approach for comparing fluxes between fields receiving mitigation treatments and control fields. However, they have rarely been applied to spatially verifying treatments aimed at mitigating nitrous oxide emission from intensively grazed pastoral systems. We deployed a micrometeorological system to compare N2O flux among several ~ 1.5 ha plots in intensively grazed dairy pasture. The sample collection and measurement system is referred to as the Field-Scale Nitrous Oxide Mitigation Assessment System (FS-NOMAS) and used a tuneable diode laser absorption spectrometer to measure N2O gradients to high precision at four locations along a 300 m transect. The utility of the FS-NOMAS to assess mitigation efficacy depends largely on its ability to resolve very small vertical N2O gradients. The performance of the FS-NOMAS was assessed in this respect in laboratory and field-based studies. The FS-NOMAS could reliably resolve gradients of 0.039 ppb between a height of 0.5 m and 1.0 m. The gradient resolution achieved corresponded to the ability to detect an inter-plot N2O flux difference of 26.4 μg N2O-N m−2 h−1 under the most commonly encountered conditions of atmospheric mixing (quantified here by a turbulent transfer coefficient), but this ranged from 11 to 59 μg N2O-N m−2 h−1 as the transfer coefficient ranged between its 5th and 95th percentile. Assuming a likely value of 100 μg N2O-N m−2 h−1 for post-grazing N2O fluxes from intensively grazed New Zealand dairy pasture, the system described here would be capable of detecting a mitigation efficacy of 26% for a single (40 min) comparison. We demonstrate that the system has considerably greater sensitivity to treatment effects by measuring cumulative fluxes over extended periods.

The ability to manipulate the genome of the whole animal has, for the past 10 years, provided researchers with an alternative route of inquiry into many complex biological processes. Transgenic animals have numerous applications, encompassing a wide range of different disciplines, but they have proved especially useful in the investigation of gene regulation and gene function within the context of the living animal. This review describes the different techniques which have been used to produce transgenic animals and highlights advances which have been achieved using the transgenic approach.

The synthesis of essential fatty acids (EFAs) that have been shown to inhibit breast cancer cell growth in vitro and tumor growth in animals requires desaturation at C-6 of linoleic or alpha-linolenic acid. This observation, combined with reports that many tumors and tumor cell lines are deficient in Delta(6) desaturation and/or contain low levels of 6-desaturated EFAs, has led to the suggestion that loss of Delta(6) desaturating ability is relevant to the process of malignant transformation. This study was undertaken in search of direct evidence that malignant transformation of mammary epithelial cells alters EFA metabolism. We used two cell lines derived from the spontaneously immortalized human mammary epithelial cell line MCF-10A and expressing either the c-Ha-ras protooncogene (MCF-10AneoN) or an activated c-Ha-ras oncogene (MCF-10AneoT), and a cell line immortalized by transfection of human mammary epithelial cells with SV40 T antigen. We compared these cell lines in terms of ability to convert EFAs (30 mu M) to other EFAs of the same family. MCF-10AneoT cells lose the ability to perform Delta(6) and Delta(4) desaturations, whereas MCF-10AneoN cells and the SV40 T antigen-transformed cell line do not. No significant changes in growth response to culture with 6-desaturated EFAs were noted for MCF-10AneoT cells compared with MCF-10AneoN and parental MCF-10A cells, suggesting that FA metabolism alone cannot account for the effects of EFAs on the growth of neoplastic and non-neoplastic mammary epithelial cells.

The tetradentate ligand, common name Salban(But)H4 (N,N'-bis(2-hydroxy-3,5-di-tert-butylbenzyl)-1,4-diaminobutane) combines with appropriate amounts of LiAlH4 to produce the unique monomeric, uni-ligated aluminate [Salban(But)Al]Li(thf)2 (1) and the bimetallic derivative Salban(But)(AlH2Li(thf)2)2 (2).

An eight-year-old female border collie was referred with a two-month history of faecal tenesmus. Ultrasonography and radiology identified fluid-filled masses in the cranial vagina. The fluid was drained from the vaginal cysts via an episiotomy and the clinical signs resolved. Histological examination confirmed that the cysts were of urogenital origin. This is believed to be the first report of vaginal cysts causing faecal tenesmus in the dog.

The response of the ovine corpus luteum of pregnancy to the luteolytic effect of prostaglandin F2 alpha (dinoprost) and its analogue, cloprostenol, was tested in both superovulated and untreated ewes by monitoring plasma progesterone concentrations at the time of 'material recognition' and beyond (days 13 to 30). On days 13, 16 and 28, the majority of the superovulated ewes were refractory to 10 mg of dinoprost. The luteolytic efficacy of 250 micrograms of cloprostenol was compared with 10 mg of dinoprost on day 20 of pregnancy in superovulated and untreated animals and the two prostaglandins were also compared on days 26 and 30 in animals previously unresponsive to dinoprost. Generally, cloprostenol was more effective than dinoprost because there was less refractoriness on day 20 and no refractoriness on days 26 and 30 to this prostaglandin. No difference in the sensitivity to this drug was found between the superovulated and untreated groups on days 20 and 26.

Eight bitches presenting with vaginal discharges were diagnosed as having open pyometra, as assessed by ultrasonographic, radiographic, haematological and clinical investigation. Plasma progesterone was assessed before treatment with prostaglandin F2 alpha (Dinoprost) and three of the bitches had low concentrations. Each bitch was given multiple injections of PGF2 alpha and monitored during and after treatment. All bitches had basal progesterone concentrations after treatment and the uterine diameters were markedly reduced by that time. One bitch has subsequently produced a litter of seven pups. Five of six bitches that were subjected to ovariohysterectomy 1-2 months later had normal uteri, although one had caseated areas in the uterine wall.

An acute phase response has been identified during mid-gestation in bitches by determination of the serum C-reactive protein (CRP) concentration. In four pregnant bitches, a large increase in CRP during mid-gestation was followed by a second increase after parturition. In three pregnant bitches, a similar increase was observed during mid-gestation but the second (post parturition) increase was not detected. In two pregnant bitches only a small rise was observed in mid-gestation. No increase in CRP was observed in the serum of two bitches that were not mated following oestrus or in the serum of two bitches that were mated but did not become pregnant. One bitch was diagnosed as pregnant by palpation but did not produce a litter and did not have a mid-gestation increase in CRP. However, this animal did show an acute phase response shortly after oestrus.

Oocytes were collected from ovaries of bitches, at various stages of the oestrous cycle, after routine sterilization. Cumulus-enclosed oocytes were cultured for 0-72 h in a modified M-199 medium containing 10% oestrous bitch serum and 20 micrograms oestradiol ml-1. For oocytes surrounded by two or more layers of cumulus cells, an increase in the expression of mRNA transcripts for zona pellucida glycoprotein 3 (ZP3) was seen and reached peak levels after 48 h culture in vitro. Histological assessment showed that 39% of these oocytes had extruded their first polar body after 24 h culture in vitro. When these in vitro matured oocytes were transferred to oviduct cell monolayers and inseminated with fresh dog spermatozoa in Medium-199 supplemented with 10% fetal calf serum and 50 mg gentamicin sulfate ml-1, penetration of the zona pellucida started 1 h after insemination for oocytes that had been cultured for 48 and 72 h. At 12 h after insemination both male and female pronuclei were seen in 37.5% and 20% of the oocytes incubated for 48 and 72 h, respectively. No further development was seen.

Real-time B-mode ultrasound imaging was carried out, using a scanner of moderate quality, on 40 fresh bitch cadavers to identify the presence of ovaries and significant ovarian structures. The results indicated that accurate identification of the ovaries depended on the presence of significant follicles or corpora lutea (CL). The findings were verified at post-mortem examination. The study was continued by scanning 35 live bitches using three different scanning units of increasingly improved quality to show that the process of ovulation could be assessed with reasonable accuracy with improved quality of equipment, although the exact fate of the follicle could not be imaged. The results were judged against assays for blood circulating progesterone. A final group of seven live bitches were scanned with a high-grade scanner using an annular phased-array transducer to attempt to image the process of ovulation. The non-echogenic follicle disappeared and was replaced by the CL that was hypoechoic with respect to surrounding tissue, thus allowing accurate assessment of the time of ovulation. This was confirmed by progesterone assay.

It is vital that lambs receive at least 50ml/kg body weight of colostrum as soon as possible after birth. Without this, the lamb will be deprived quickly of energy for thermoregulation, as well as antibody protection. Colostrum contains high levels of fats and lactose, proteins and vitamins; however the consistency and colour vary between individual animals. Little is known of the cause of these variations. This experiment aimed to examine whether there were breed, age, genotype and litter size differences in the fat and protein levels of ewe colostrum collected within one hour of parturition.

The effect of pH and temperature on the capacity and binding of Bacillus stearothermophilus, alcohol dehydrogenase and phosphofructokinase to N6-(6-aminohexyl)-5′-AMP-Sepharose has been examined. Specific elution from the substituted AMP-Sepharose was examined using a variety of cofactors, fragments of cofactors and substrates. A purification scheme for each enzyme on the substituted AMP-Sepharose using nucleotides and gradients of pH and salt is presented. Interestingly, elevated temperature increased the affinity of both enzymes for N6-(6-aminohexyl)-5′-AMP-Sepharose, however, the Michaelis constant for nucleotide determined at various temperatures remained constant. The effect of pH and salt concentration on the binding of B. stearothermophilus glyceraldehyde-3-phosphate dehydrogenase to 6-aminohexanoyl-NAD+-Sepharose was also examined; raising the pH above 7.5 lowers the capacity of the matrix and the effect of a range of ammonium sulphate concentrations on the adsorption of the enzyme was examined. A specific purification of glyceraldehyde-3-phosphate dehydrogenase from partially purified extracts of this organism was achieved.

The catch from the fishery for the migratory Prochilodus platensis Holmberg on the Rio Pilcomayo shows considerable annual variation. Peaks were apparent in 1981 and 1982, followed by very low returns between 1983 and 1985 and a resurgence in 1986. The catch in 1986 was 1011t with the degree of annual variation probably lying between 500 and 2000t. In the Pilcomayo P. platensis is a rapidly growing short-lived fish with a maximum life expectancy of 6-7 years and an upper size approaching 61.5cm. The fish first migrate and appear in Bolivian’ waters when they are 21/2-3 years old, having spent the first 2 years on the nursery grounds, probably on the Argentine/Paraguay section of the river. Although fish of this age were numerous in the 1986 catches, the optimal market size is rather larger, and older fish are taken preferentially. The fishery actually depends upon very few age classes. A comparison of growth and mortality rates obtained from scale reading and from length frequency analysis by ELEFAN programs showed a close agreement. The considerable fluctuations in the fishery are largely due to the highly variable flood regime of the river rather than to fishing pressure, with the flood determining recruitment in 2 years’ time. Nevertheless, a combination of a sequence of poor flood years with sustained fishing pressure could seriously damage the fishery.

The data reported in the literature concerning the uses and composition of yarrow,Achillea millefolium aggr., Compositae, are compiled and discussed. Historically, this plant has been extensively used as a herbal remedy for numerous afflictions by many cultures on several continents. It has also been the subject of a considerable number of scientific investigations. It has, however, not been previously reviewed. Analysis of available information demonstrates the value of continued phytochemical investigations of folklore remedies.

1. 6-phosphogluconate dehydrogenase from sheep liver has been purified 350-fold by affinity chromatography with a final specific activity of 18 micronmol of NADP+/reduced min per mg of protein and an overall yield of greater than 40%. 2. A systematic investigation of potential ligands has been carried out: these included 6-phosphogluconate and NADP+, pyridoxal phosphate and several immobilized nucleotides. The results indicate that NADP+ is the most suitable ligand for the purification of 6-phosphogluconate dehydrogenase. 3. The effects of pH and alternative eluents have been examined in relation to the parameters known to affect the desorption phase of affinity chromatography; careful manipulation of the elution conditions permitted the separation of glucose 6-phosphate dehydrogenase, glutathione reductase and 6-phosphogluconate dehydrogenase from sheep liver on NADP+-Sepharose 4B. 4. A large-scale purification scheme for 6-phosphogluconate dehydrogenase is presented that uses the competitive inhibitors inorganic pyrophosphate and citrate as specific eluents.

3-Hydroxybutyrate dehydrogenase (EC 1.1.1.30) and malate dehydrogenase (EC 1.1.1.37) were purified to homogeneity on a large scale involving only two sequential affinity-chromatography steps on two triazine dye-Sepharose matrices. Recoveries of both enzymes were in excess of 60%. Malate dehydrogenase could also be purified by a combination of triazine dye affinity chromatography and gel filtration on Ultrogel AcA-44, but this offered no significant advantage over the purely affinity procedure.

Canine semen was obtained by digital manipulation from two donor dogs and twelve stud dogs. The sperm-rich fraction was diluted with either of two different diluents and the survival of spermatozoa before and after freezing was determined. It appeared that there was no difference in the post-thaw survival rate in either of the diluents used.

Summary 1. The interrelationships of five western European violets are determined by examining chromosome pairing in their F1 hybrids. Viola stagnina Kit. (n= 10), V. pumila Chaix. (n= 20), V. canina L. sspp. canina and montana (L.) Fries. (n= 20) and V. lactea Sm (n= 29) belong to the group Arosulatae and Viola riviniana Rchb. (n= 20) is in the group Rosulantes. 2. (a) Seven artificial interspecific hybrids were studied and the most frequent meiotic chromosomal arrangements can be summarized as follows: Viola canina × lactea (2n= 49)—2011+91; V. canina × stagnina (2n= 30)—101 + 101; V. canina (sspp. canina and montana) × riviniana (2n= 40)—1011+201; V. lactea × riviniana (2n= 49)—1011+291; V. pumila × canina (2n= 40)—1011 + 201; V. lactea × pumila (2n= 49)—1011+291. (b) V. canina ssp. canina × riviniana and V. lactea × riviniana also had supernumerary chromosomes, derived from their riviniana parent. These varied in number, even between the p.m.c. of a single hybrid plant, which suggests somatic chromosomal irregularity, possibly during premeiotic mitosis. (c) The two hybrids involving V. pumila frequently showed a high proportion of multivalents, as well as ‘clumping’ of the bivalents; the univalents were generally distinct but some tended to show secondary association at M1. 3. The genomic constitutions of the species were deduced from the chromosome pairing in the hybrids. The species are seen to be related in a reticulate pattern which is based on the combination of genomes by allopolyploidy. Within this pattern the groups, Arosulatae and Rosulantes, merge into one another, at least one genome being shared by species in each group. 4. The affinities and origin of Viola lactea are discussed. It is an allohexaploid deriving two genomes from V. canina. The species carrying the third genome cannot be found in western Europe and it is suggested that, if it still exists, it may be among the diploid Arosulatae in eastern Asia.