Purification,characterization and comparison of glutathione S-transferases from black-grass (Alopecurus myosuroides Huds) biotypes

In the UK biotypes of black-grass (Alopecurus myosuroides Huds) showing resistance to both chlorotoluron (CTU) and aryloxyphenoxypropionate graminicides are increasingly being observed. Although the precise mechanisms involved in this resistance have yet to be identified, increased herbicide metabolism has been implicated as being involved in at least some cases of resistance. Glutathione S-transferases (GSTs) are a group of enzymes which have been demonstrated to metabolise herbicides in some plants, and the resistant black-grass biotype Peldon contains approximately double the GST activity towards 1-chloro-2,4-dinitrobenzene (CDNB) of susceptible biotypes. To investigate further the possible role of GSTs in herbicide resistance in black-grass, a purification procedure has been developed for these enzymes. A 27.5 kDa polypeptide possessing GST activity was purified from the susceptible biotype Herbiseed. Purification of GSTs from the resistant biotype Peldon also identified this polypeptide along with an additional 30 kDa polypeptide. An in-vitro kinetic study of both crude and purified GST extracts, and western blot analysis using antisera raised against the 27.5 kDa polypeptide, suggest that the 30 kDa polypeptide may possess GST activity, and is not a precursor of the 27.5 kDa polypeptide. These results are discussed and compared to GST profiles for other weeds and crops demonstrating herbicide resistance or tolerance. © 1999 Society of Chemical Industry     

Demographics of cattle positive for Mycobacterium avium subspecies paratuberculosis by faecal culture,from submissions to the Cork Regional Veterinary Laboratory

The demography of bovine infections caused by Mycobacterium avium subspecies paratuberculosis (MAP) in Ireland is poorly defined. The objective of this study was to describe the demographics of cattle positive to MAP on faecal culture, based on submissions to the Cork Regional Veterinary Laboratory (Cork RVL) from 1994 to 2006. The study focused on all available faecal samples from adult cattle with non-responsive chronic diarrhoea that were submitted by private veterinary practitioners to Cork RVL for MAP culture. For each MAP-positive by faecal culture animal, data were collated from Cork RVL and Cattle Movement Monitoring Scheme (CMMS) records. Johne's disease (JD) was confirmed in 110 animals from 86 herds by the Cork RVL between 1994 and 2006, with a rate of positive cases between 15% and 18% over last four years of the study. Two breeds (Holstein/Friesian or Limousin) made up 78% of submissions. Movements were assessed for the 57 study animals with available movement information, 90% died within one year of the test and 26% tested positive in the herd they were born into. The study provides preliminary information about movement trends and demographics of animals with MAP positive submissions. Although the study area is restricted, it includes the most intensive (and economically-important) dairy region in Ireland. The demographics of JD infection from the study area are in agreement with international reports. Further work is required to determine demographic trends, incidence and prevalence of JD throughout Ireland. It is hoped this work may contribute to the development of a surveillance strategy for MAP by regional veterinary laboratories.     

Antioxidative Effects of Astaxanthin against Nitric Oxide‐Induced Oxidative Stress on Cell Viability and Gene Expression in Bovine Oviduct Epithelial Cell and the Developmental Competence of Bovine IVM/IVF Embryos

The aim of the present study was to elucidate the fundamental mechanism of bovine oviduct epithelial cell (BOEC) co‐culture on developmental capacity of bovine in vitro oocyte maturation/in vitro fertilization (IVM/IVF) embryos. We examined the effects of astaxanthin against nitric oxide‐induced oxidative stress on cell viability by MTT assay, lipid peroxidation (LPO) by using thiobarbituric acid (TBA) reaction for malondialdehyde (MDA) and the expression of antioxidant genes (CuZnSOD, MnSOD and Catalase) or apoptosis genes (Bcl‐2, Caspase‐3 and Bax) by RT‐PCR in BOEC. We also evaluated the developmental rates of bovine IVM/IVF embryos co‐cultured with BOEC pre‐treated with astaxanthin (500 μm ) in the presence or absence of sodium nitroprusside (SNP, 1000 μm ) for 24 h. Cell viability in BOEC treated with SNP (50–2000 μm ) lowered, while astaxanthin addition (50–500 μm ) increased it in a dose‐dependent manner. Cell viability in astaxanthin plus SNP (1000 μm ) gradually recovered according to the increase in astaxanthin additions (100–500 mm ). The LPO in astaxanthin group (50–500 μM) gradually decreased in a dose dependent manner and among SNP or astaxanthin plus SNP group, SNP alone and astaxanthin (50 μM) plus SNP shown a significant increase than other groups (p < 0.05). Expression of apoptosis or antioxidant genes was detected by RT‐PCR. Bcl‐2 and antioxidant genes were detected in astaxanthin or astaxanthin plus SNP group, and Caspase‐3 and Bax genes were only found in SNP group. When bovine IVM/IVF embryos were cultured for 6–7 days under co‐culture system such as BOEC treated with astaxanthin in the presence or absence of SNP, the developmental ability to blastocysts in 500 μm astaxanthin group was the highest of all groups. These results suggest that astaxanthin has a antioxidative effect on cell viability and LPO of BOEC, and development of bovine IVM/IVF embryos due to the induction of antioxidant genes and suppression of apoptosis genes.     

Aboveground biomass and nitrogen in four short-rotation woody crop species growing with different water and nutrient availabilities

We quantified the effect of water and nutrient availability on aboveground biomass and nitrogen accumulation and partitioning in four species from the southeastern United States, loblolly pine (Pinus taeda), slash pine (Pinus elliottii), sweetgum (Liquidambar styraciflua), and sycamore (Platanus occidentalis). The 6-year-old stands received five levels of resource input (control, irrigation with 3.05 cm water week⁻¹, irrigation + 57 kg N ha⁻¹ year⁻¹, irrigation + 85 kg N ha⁻¹ year⁻¹, and irrigation + 114 kg N ha⁻¹ year⁻¹). Irrigation significantly increased foliage, stem, and branch biomass for sweetgum and sycamore, culminating in 103% and 238% increases in total aboveground biomass. Fertilization significantly increased aboveground components for all species resulting in 49, 58, 281, and 132% increases in total aboveground biomass for loblolly pine, slash pine, sweetgum, and sycamore, respectively. Standing total aboveground biomass of the fertilized treatments reached 79, 59, 48, and 54 Mg ha⁻¹ for loblolly pine, slash pine, sweetgum, and sycamore, respectively. Fertilization increased foliar nitrogen concentration for loblolly pine, sweetgum, and sycamore foliage. Irrigation increased total stand nitrogen content by 6, 14, 93, and 161% for loblolly pine, slash pine, sweetgum, and sycamore, respectively. Fertilization increased total nitrogen content by 62, 53, 172, and 69% with maximum nitrogen contents of 267, 212, 237, and 203 kg ha⁻¹ for loblolly pine, slash pine, sweetgum, and sycamore, respectively. Growth efficiency (stem growth per unit of leaf biomass) and nitrogen use efficiency (stem growth per unit of foliar nitrogen content) increased for the sycamore and sweetgum, but not the loblolly or slash pine.     

Dissociative anaesthesia in free-ranging male koalas and selected marsupials in captivity

Forty seven free-ranging, adult, male koalas were captured and administered an intramuscular injection of the dissociative anaesthetic, Telazol (tiletamine HCl plus zolazepam HCl), at dose rates of 5.0 to 7.7 mg/kg body weight. Anaesthesia induction was rapid and smooth and resulted in a surgical plane of anaesthesia lasting 30 to 45 min. There was no depression of heart rate or respiration. Mild salivation occurred in most animals, but was not a problem because the swallowing reflex was retained. There was no mortality or morbidity and the anaesthesia level was sufficient to allow electroejaculation and multiple blood sampling with no apparent animal discomfort. For 10 of 19 males in which anaesthesia was required for a 90 min protocol, a supplementary Telazol injection (average, 2.5 mg/kg) was necessary. All koalas recovered completely within 3 to 4 h of the initial injection. The results suggest that the optimal Telazol dosage for the adult male koala is 7.0 mg/kg body weight. The retrospective analysis of 259 anaesthesia records involving 14 species indicated that Telazol was equally effective and safe in other captive marsupials.     

Isolation and characterisation of two glucosyltransferases from Glycine max associated with bentazone metabolism

Two glucosyltransferases capable of glucosylating the primary major bentazone metabolite, 6-hydroxybentazone, have been isolated from tolerant soybean (Glycine max (L.) Fiskerby V) tissue. A soluble flavonol glucosyltransferase, whose primary substrate was kaempferol, was isolated from 3-week-old light-grown tissue. This enzyme had a relative molecular mass of 44 600, a pH optimum of 6·3 and Michaelis constants for kaempferol and 6-hydroxybentazone of 0·09 and 2·45 mM respectively. A membrane-bound glucosyltransferase whose primary substrate was the intermediate shikimic acid metabolite, p-hydroxyphenylpyruvic acid, was also isolated from 7-day-old etiolated tissue. This enzyme had a relative molecular mass of 53000 (which could be dissociated to approximately 28000), a pH optimum of 7·5 and Michaelis constants for p-hydroxyphenylpyruvic acid and 6-hydroxybentazone of 0·11 and 1·96 mM respectively. These results suggest that 6-hydroxybentazone, and possibly many other hydroxylated pesticides, may be further detoxified by several glucosyltransferases with overlapping specificity whose primary role involves the storage of endogenous metabolites.     

Using policy goals to evaluate red wolf reintroduction in eastern North Carolina

Despite being politicized in its early stages, the Red Wolf (Canis rufus) Recovery Program (RWRP) existed for 30 years in eastern North Carolina with little attention paid to finding common ground between policy contestants. We situated our data from 62 key informant interviews within Stone’s (2002) policy goals framework to evaluate red wolf recovery in eastern North Carolina, United States. Four goals underpin U.S. political culture and offer common ground with which to begin negotiation among policy contestants. Our results highlight challenges to achieving one definition prescribing how to treat each policy goal. The future of recovery within the red wolf’s historic range could hinge on decision-makers’ willingness to prioritize policy design over policy tool evaluation, developing a process by which to achieve an agreed-upon set of values underscoring red wolf recovery. This process must reconcile disagreements about what is fair or equitable treatment of landowners and include local-level experiences.     

Interglacial hydroclimate in the tropical West Pacific through the Late Pleistocene

Records of atmospheric carbon dioxide concentration (P(CO(2))) and Antarctic temperature have revealed an intriguing change in the magnitude of interglacial warmth and P(CO(2)) at around 430,000 years ago (430 ka), but the global climate repercussions of this change remain elusive. Here, we present a stalagmite-based reconstruction of tropical West Pacific hydroclimate from 570 to 210 ka. The results suggest similar regional precipitation amounts across the four interglacials contained in the record, implying that tropical hydroclimate was insensitive to interglacial differences in P(CO(2)) and high-latitude temperature. In contrast, during glacial terminations, drying in the tropical West Pacific accompanied cooling events in northern high latitudes. Therefore, the tropical convective heat engine can either stabilize or amplify global climate change, depending on the nature of the climate forcing.