Chemical and mineralogical weathering rates and processes in an upland granitic till catchment in Scotland   总被引：1，自引：0，他引：1  

D. C. Bain  A. Mellor  M. J. Wilson  D. M. L. Duthie 《Water, air, and soil pollution》1994,73(1):11-27

Weathering in an upland granitic till catchment receiving an intermediate level of acidic deposition has been studied by chemical and mineralogical analyses of soil profiles and chemical analysis of precipitation and streamwater. Long-term weathering rates for base cations calculated from analyses of soil profile horizons using Zr as an internal, immobile, index element are similar for alpine podzols and peaty podzols and are 2–3 meq.m^–2.a^–1 for Ca and Mg, and 10–11 meq.m^–2.a^–1 for K and Na. The high loss of Na is associated with the weathering of oligoclase, particularly in the coarse sand fraction. Loss of K is related to weathering of K-feldspar and micas. Current weathering rates for base cations calculated from input-output budgets are higher than long-term rates by factors of 12, 8 and 3 for Ca, Mg and Na, but lower by a factor of 7 for K probably due to biomass uptake. The higher current overall loss of base cations may be due to increased rates of weathering in recent times but this is not conclusive as there are large uncertainties inherent in both methods of estimation.  相似文献   

A preliminary review of weathering rates in relation to their method of calculation for acid sensitive soil parent materials     

S. J. Langan  M. E. Hodson  D. C. Bain  R. A. Skeffington  M. J. Wilson 《Water, air, and soil pollution》1995,85(3):1075-1081

The release of base cations from chemical weathering is the fundamental process by which base cations lost through leaching or biological uptake are replenished. Soils with a high content of easily weatherable minerals will, in general, be readily able to neutralise incoming acidity and satisfy biological requirements through this supply of base cations from weathering. Conversely those soils with a low content of such minerals will be unable to buffer acid inputs or meet biological demands and will be vulnerable to acidification. It is evident therefore that an accurate estimate of the rate of chemical weathering is a prerequisite for any assessment of ecosystem sensitivity to acidification. The principal methods by which these calculations are made can be grouped into those based on element depletion in soil horizons calculated against a conservative element reference, catchment fluxes, laboratory studies and the use of mathematical models which utilise data from each of these sources. A review of the published data has been undertaken to determine if a systematic variation in weathering rates can be observed for a range of parent materials and/or methods used. Variations of 0.03–0.8 keq ha^?1yr^?1 for K⁺, 0.0–1.0 keq ha^?1yr^?1 for Na⁺, 0.01–1.39 keq ha^?1yr^?1 for Mg²⁺ and 0.0–5.8 keq ha^?1yr^?1 for Ca²⁺ were found. In general individual cation weathering rates determined from catchment fluxes, and also the model MAGIC, are dominated by Ca²⁺, with Mg²⁺ being the next most significant release rate. However it has not been possible to determine any other systematic variations due to the limited number of sites where weathering rate has been determined by more than one method.  相似文献   

Genetic analysis of infectious pancreatic necrosis virus from Scotland     

Bain N  Gregory A  Raynard RS 《Journal of fish diseases》2008,31(1):37-47

Infectious pancreatic necrosis (IPN) is a highly contagious disease of young salmonid fish, and is one of the most serious economic diseases in aquaculture. In Scotland, an increase in IPN virus (IPNV) outbreaks in seawater Atlantic salmon, Salmo salar, has been reported in recent years. The aim of this study was to analyse the VP2 gene from recent IPNV isolates from Scotland, to determine whether there are epidemiological links between IPNV isolates from farms (13), wild fish (17) and the environment (6) in order to investigate potential wild and farmed fish interactions. Comparison of the nucleotide sequence of the VP2 gene revealed that 34 of 36 isolates were 97.1-100% similar and the deduced amino acid sequences showed 97-100% identity. Two isolates from wild fish exhibited the most divergence at 85-87.3% similarity to the other isolates at the nucleotide level and 88.2-90.8% identity at the deduced amino acid level. Phylogenetic analyses revealed that 34 of 36 of the isolates from Scotland were genetically closely related to the A2 (Sp) serotype of IPNV. The two wild isolates from seatrout, Salmo trutta, and flounder, Platichthys flesus, were most closely related to the European A5 (Te) serotype. This study represents a comprehensive IPNV phylogenetic study that indicates that there are closely related or identical isolates in circulation in the marine environment, which adds evidence that disease interactions between wild and farmed fish may occur. This type of analysis is a useful tool in the management and control of fish diseases because it can assist in the identification of epidemiological links and highlight potential risks to aquaculture.  相似文献   

Production of biologically active equine interleukin 12 through expression of p35, p40 and single chain IL-12 in mammalian and baculovirus expression systems.     

E L McMonagle  S Taylor  H van Zuilekom  L Sanders  N Scholtes  L J Keanie  C A Hopkins  N A Logan  D Bain  D J Argyle  D E Onions  V E Schijns  L Nicolson 《Equine veterinary journal》2001,33(7):693-698

Interleukin-12 (IL-12) is a key cytokine in the development of cell-mediated immune responses. Bioactive IL-12 is a heterodimeric cytokine composed of disulphide linked p35 and p40 subunits. The aim of this study was to verify biologically activity of the products expressed from equine interleukin-12 (IL-12) p35 and p40 cDNAs and to establish whether equine IL-12 could be expressed as a p35/p40 fusion polypeptide, as has been reported for IL-12a of several mammalian species. We report production of equine IL-12 through expression of p35 and p40 subunits in mammalian and insect cells and of a p35:p40 fusion polypeptide in mammalian cells. Conditioned medium recovered from cultures transiently transfected with constructs encoding equine p35 and p40 subunits or single chain IL-12 enhanced IFN-gamma production in cells derived from equine lymph nodes. Preincubation of IFN-gamma inducing preparations with anti-p40 monoclonal antibody resulted in a significant decrease in IFN-gamma induction capacity. Medium recovered from p35 and p40-expressing baculovirus infected cultures enhanced target cell IFN-gamma production and proliferation. Experimental studies in mice and other animals have revealed a therapeutic benefit of IL-12 in cancer, inflammatory and infectious disease and an adjuvant effect in prophylactic regimes. Production of a bioactive species-specific IL-12 is a first step towards an investigation of its potential application in equine species.  相似文献   

The processing potential of tubers of the cultivated potato,Solanum tuberosum L., after storage at low temperatures. 2. Sugar concentration     

J. Brown  G. R. Mackay  H. Bain  D. W. Griffith  M. J. Allison 《Potato Research》1990,33(2):219-227

Summary Several clones from a potato breeding programme at the Scottish Crop Research Institute (SCRI) produced acceptable (pale) coloured fry products after five months' storage at 4°C. Chemical analysis of tuber samples taken at five-week intervals during storage at 4°C and 10°C gave a substantial variation in glucose, fructose and sucrose concentrations among the 22 clones examined. Several unnamed SCRI clones showed little accumulation of reducing sugars when stored at 4°C. In marked contrast, the cultivars Record and Pentland Dell, currently the most widely used cultivars for fry processing in the UK, accumulated far greater levels of sugar during low temperature storage. Glucose concentration proved more important than fructose concentration in determining fry colour. Clones with the lowest concentrations of glucose after storage at 4°C also showed lowest concentrations when stored at 10°C. These results are in agreement with previous reports on the predictive value of glucose levels at harvest, but this is the first identification of such low temperature, low sweetening variants in agronomically adapted clones of the cultivated tetraploid potato.  相似文献   

Morphological and molecular data on the dermal microfilariae of a species of Cercopithifilaria from a dog in Sicily     

Otranto D  Brianti E  Dantas-Torres F  Weigl S  Latrofa MS  Gaglio G  Cauquil L  Giannetto S  Bain O 《Veterinary parasitology》2011,182(2-4):221-229

Dermal microfilariae found in a dog from Sicily, Italy, were characterized morphologically and genetically and differentiated from those of all the other blood microfilariae commonly found in dogs. In particular, the microfilariae were short (mean length of 186.7 μm), presented a body flattened dorso-ventrally and a rounded head, bearing a tiny cephalic hook. The genetic identity of microfilariae herein studied was also assessed by molecular amplification, sequencing and analyzing of multiple ribosomal ITS-2 and mitochondrial (cox1 and 12S) target genes. Both morphologic and genetic characterization as well as the molecular phylogenetic history inferred using sequences of a barcoding dataset were concordant in supporting the identification of Cercopithifilaria at the genus level. Surprisingly, microfilariae here examined were well distinct from Cercopithifilaria grassii (Noè, 1907), from northern Italy, and resembled those of a species described in Brazil, Cercopithifilaria bainae Almeida & Vicente, 1984. This paper provides evidence for the existence of a Cercopithifilaria species infesting a dog from Sicily and also presents a PCR protocol on skin samples as a tool for further epidemiological studies, which could provide evidence on the aetiology and the natural history of this filarial species.  相似文献   

The effect of storage temperature on reducing sugar concentration and the activities of three amylolytic enzymes in tubers of the cultivated potato,Solanum tuberosum L.   总被引：1，自引：0，他引：1  

J. E. Cottrell  C. M. Duffus  L. Paterson  G. R. Mackay  M. J. Allison  H. Bain 《Potato Research》1993,36(2):107-117

Summary Reducing sugar content, and activities of three starch hydrolysing enzymes, alpha-amylase, beta-amylase and debranching enzyme were measured over several months in tubers of five cultivars stored at 4°C or 10°C. Cultivars differed in their sensitivity to storage temperature. Reducing sugar content of tubers and the activities of three starch hydrolysing enzymes increased sharply during the first weeks of storage at 4°C. At 10°C, reducing sugar content, and the activity of the three enzymes remained constant or increased only slightly. Deceased.  相似文献   

Production of Oocytes of Nile Tilapia (Oreochromis niloticus) for In Vitro Fertilization via Hormonal Treatments     

DAA Oliveira  CG Aleixo  SA Prado  RK Luz  NLAF Sarmento  EA Teixeira  MR Luz  EM Turra 《Reproduction in domestic animals》2013,48(6):1049-1055

Only a few studies have described hormonal treatments for induction of synchronicity and gamete collection in Nile tilapia (Oreochromis niloticus), both important for assortative matings in breeding programmes and essential for polyploidy technologies. In this study, we compared the effectiveness of carp pituitary extract (CPE), Nile tilapia pituitary extract (TPE), human chorionic gonadotropin (hCG) and gonadotropin‐releasing hormone (GnRH) protocols on the induction of spawning and egg production in Nile tilapia. Among the hormonal treatments analysed, only hCG was effective for producing viable gametes for in vitro fertilization. To verify the viability of this hormonal treatment, hCG was tested using different doses (1000, 2000, 3000, 4000 and 5000 IU/kg) in a large number of females (208 animals) from two Nile tilapia lines. The results indicated that hCG doses between 1000 and 5000 IU/kg could be used to induce final oocyte maturation in Nile tilapia with collection of stripped oocytes. This is the first study to report differential reproductive responses to hormonal treatment between tilapia lines: line 1 was more efficient at producing eggs and post‐hatching larvae after hCG induction than line 2. In conclusion, we demonstrated that the hCG protocol may be applied on a large scale to induce final oocyte maturation in Nile tilapia. The development of a protocol for in vitro fertilization in Nile tilapia may aid in breeding programmes and biotechnological assays for the development of genetically modified lines of Nile tilapia.  相似文献   

Framing and reframing the environmental risks and economic benefits of ethanol production in Iowa     

Carmen Bain  Theresa Selfa 《Agriculture and Human Values》2013,30(3):351-364

Recent research exposing environmental and social externalities of biofuels has undermined the earlier national consensus that they would provide climate mitigation and rural development benefits, but support for ethanol remains strong in Iowa. The objective of this paper is to understand how stakeholder groups in Iowa have framed the benefits and risks associated with ethanol’s impact on the local economy and environment. Our case study draws on in-depth, semi-structured interviews conducted with key informants from agricultural organizations, environmental organizations, and government departments in the state. We find that in Iowa, widespread support for ethanol production exists among government, energy, and farm groups, and that they frame ethanol production as economically beneficial to rural communities and agriculture, while minimizing the possibility of associated environmental risks. Although participants from environmental organizations in Iowa express apprehension about the environmental impacts of expanded corn ethanol production, their unease is muted in relation to economic benefits and in relation to other environmental issues, and few have publicly voiced their concerns. To understand these findings, we draw from the environmental sociology literature that examines the role of powerful natural resource interests in framing the importance of resource extraction and commodity production to community identity and economy and in delegitimizing and naturalizing associated environmental issues and problems. We argue that powerful natural resource interests in Iowa both naturalize environmental problems related to ethanol production and engage in diversionary reframing to emphasize the economic benefits while minimizing or rejecting the potential environmental risks.  相似文献   

A survey of wild marine fish identifies a potential origin of an outbreak of viral haemorrhagic septicaemia in wrasse,Labridae, used as cleaner fish on marine Atlantic salmon,Salmo salar L., farms          下载免费PDF全文

I S Wallace  K Donald  L A Munro  W Murray  C C Pert  H Stagg  M Hall  N Bain 《Journal of fish diseases》2015,38(6):515-521

Viral haemorrhagic septicaemia virus (VHSV) was isolated from five species of wrasse (Labridae) used as biological controls for parasitic sea lice predominantly, Lepeophtheirus salmonis (Krøyer, 1837), on marine Atlantic salmon, Salmo salar L., farms in Shetland. As part of the epidemiological investigation, 1400 wild marine fish were caught and screened in pools of 10 for VHSV using virus isolation. Eleven pools (8%) were confirmed VHSV positive from: grey gurnard, Eutrigla gurnardus L.; Atlantic herring, Clupea harengus L.; Norway pout, Trisopterus esmarkii (Nilsson); plaice, Pleuronectes platessa L.; sprat, Sprattus sprattus L. and whiting, Merlangius merlangus L. The isolation of VHSV from grey gurnard is the first documented report in this species. Nucleic acid sequencing of the partial nucleocapsid (N) and glycoprotein (G) genes was carried out for viral characterization. Sequence analysis confirmed that all wild isolates were genotype III the same as the wrasse and there was a close genetic similarity between the isolates from wild fish and wrasse on the farms. Infection from these local wild marine fish is the most likely source of VHSV isolated from wrasse on the fish farms.  相似文献