Second Irish Crop Protection Conference; Dublin, 18th-19th October 1966     

T. M. THOMAS 《Weed Research》1967,7(1):87-88

  相似文献   

Higher Education on Urban Forestry in Europe: An Overview     

ANDERSEN FRODE  KONIJNENDIJK CECIL C  RANDRUP THOMAS B 《中国林业科技(英文版)》2003,(3)

In order to meet the demands of modern, information-based society, higher education in natural resource management needs to be transformed. Enhanced mobility of students and staff, multi- and transdisciplinary approaches, as well as innovative educational approaches are called for. Moreover, the urban component needs to be better incorporated, as exemplified by the emerging field of urban forestry. This paper relates to the developments in higher education within the context of education on urban forests and urban trees in Europe. Presented here are the main findings of a comparative European study led by the Danish Forest and Landscape Research Institute within the framework of the EU-funded COST Action E12 'Urban Forests and Trees'. In order to obtain an overview of the status of higher education on urban forestry in Europe, 180 educational institutions in 28 countries were sent a questionnaire. Results show that urban forestry is an expanding element of European education, as urban elements are becom  相似文献   

The Interaction of Green Spruce Aphid and Fertilizer Applications on the Growth of Sitka Spruce     

THOMAS  R. C.; MILLER  H. G 《Forestry》1994,67(4):329-341

In an 11-year-old stand of Sitka spruce (Picea sitchensis [Bong.]Carr.) application of nitrogen fertilizers, at a rate of 10kgN ha^–1 month^–1, increased mean diameter incrementby 12 per cent, while the further addition of phosphorus, at5 kg ha^–1 month^–1, resulted in a 23 per cent increase.An attack by the green spruce aphid (Elatobium albietinum Walker)occurred during the period of fertilizer addition. The mostseverely affected trees showed a reduction in diameter growthof 50 to 56 per cent but the severity of the attack betweentrees was unrelated to the treatments applied. However, fertilizerapplication did hasten the recovery of diameter growth afterdefoliation.  相似文献   

Fish utilisation of managed realignments   总被引：3，自引：0，他引：3  

S. COLCLOUGH  L. FONSECA  T. ASTLEY  K. THOMAS  & W. WATTS 《Fisheries Management and Ecology》2005,12(6):351-360

Abstract  One area of ecological benefit not yet fully evaluated in European waters is the utilisation of restored saltmarsh habitats by fish species. This study examines the utilisation of managed realignments and relic saltmarsh by fish species. Factors affecting habitat heterogeneity and fish populations are discussed, and recommendations are made with respect to scheme design and management that will maximise the biological and socio-economic values. Fish populations in the high intertidal areas were assessed using a suite of techniques, including observations on feeding behaviour. Each microhabitat was discussed as a function of the extent of fish colonisation. A positive relationship between the degree of fish utilisation and habitat heterogeneity was ascertained using species richness, abundance and behavioural observations. This study will aid habitat valuation for economic justification of managed realignments, over and above existing drivers, such as compensatory habitat for encroachment, flood defence and the European Union Habitats Directive. The work now forms part of a wider European Interreg IIIb project, COMCOAST.  相似文献   

In vivo and in vitro cell-mediated immune responses of rainbow trout, Oncorhynchus mykiss (Walbaum), against Cryptobia salmositica Katz, 1951 (Sarcomastigophora: Kinetoplastida)     

P. T. THOMAS  P. T. K. WOO 《Journal of fish diseases》1990,13(6):423-433

Abstract. Delayed-type hypersensitivity (DTH) reaction (an in vivo manifestation of cell-mediated immunity) was detected in Oncorhynchus mykiss maintained on a pantothenic-acid-supplemented diet 2 weeks after infection with Cryptobia salmositica. The reaction was similar to that in mammals with mononuclear cell infiltration into the dermis and muscle layers and the presence of oedema. DTH reaction was also displayed by fish on a pantothcnic-acid-supplemented diet that had recovered from the infection and were protected against further infection. The reaction was less marked in infected or protected fish on a pantothenie-acid-deficient diet. Inhibition of macrophage migration (an in vitro expression of cell-mediated immunity) was observed when head kidney cell suspensions from protected fish maintained on either pantothenic acid supplemented or deficient diets were incubated with Cryptobia antigen. No inhibition of migration was evident when head kidney cell suspensions from the above fish were incubated without antigen, nor was it evident when cells from uninfected fish were used. The occurrence of a typical DTH reaction in rainbow trout and the feasibility of assessing it by measuring the thickness of the induration provides a simple and practical method for assessing cell-mediated immunity in large scale vaccination programmes against pathogens.  相似文献   

Dietary modulation of humoral immune response and anaemia in rainbow trout, Oncorhynchus mykiss (Walbaum), infected with Cryptobia salmositica Katz, 1951     

P. T. THOMAS  P. T. K. WOO 《Journal of fish diseases》1990,13(6):435-446

Abstract. The humoral immune response in Cryptobia-salmositica -infected rainbow trout on pantothenic-acid-deficient/low protein (19%) diets was depressed. There was no significant difference in parasitaemia between fish on the pantothenic-acid-deficient diet and those on the supplemented diet; however, the parasitaemia in fish on 19% protein diet was significantly lower than that in fish on 38% protein diet. The low humoral responders, in contrast to the high responders (on 38 and 29% protein diets), had less severe anaemia and the packed cell volume at the end of the experiment was not significantly different from that at 2 weeks post-infection. Red cells from the low responders were Coombs' negative while those from the high responders were Coombs' positive from 4 to 6 weeks post-infection. The authors suggest that, in the low responders, red cell destruction is essentially due to the'lytic component' of the parasite antigen in contrast to the involvement of both the ^llytic' and the 'immune complex-forming' components in the high responders. The present study indicates that certain deficient diets are useful in modulating the parasitaemia and also in decreasing red cell destruction. Therefore, dietary modification may help in altering the course of such infections and the progression of the disease.  相似文献   

Cryptobia salmositica: an in vitro and in vivo study on the mechanism of anaemia in infected rainbow trout, Salmo gairdneri Richardson     

P. T. THOMAS  P. T. K. WOO 《Journal of fish diseases》1988,11(5):425-431

Abstract. There are two basic antigenic components in Cryptobia that are responsible for the anaemia in infected rainbow trout. A 'lytic component', which is dosage-dependent, causes lysis of red blood cells independent of antibody or complement. The second, an 'immune-complex-forming component', attaches to red blood cells, forms immune complexes with specific antibody and activates complement resulting in haemolysis. These two antigenic components, from both live and lysed Cryptobia , were present in the serum of infected fish. When sonicated antigen or heat-inactivated antiserum (from infected fish) was incubated with red cells from uninfected fish, a portion of the red cells was lysed and a positive Coombs' reaction was observed with the remaining intact red cells. The positive Coombs' reaction was due to immune complexes adsorbed onto the red cells and these lysed when incubated with complement. Antibody by itself did not adsorb onto the red cells. From the fourth week post-infection, a positive Coombs' reaction was observed in all infected fish and haemolysis occurred with complement. The authors suggest that, in infected fish, one or more components of the complement cascade is depleted continually during infection and that the anaemia is due to the lytic action of the antigen and immune complex formation on red cells. These lead to intra-vascular haemolysis as well as erythrophagocytosis. In general, the mechanism of anaemia in cryptobiosis appears similar to that in African trypanosomiasis.  相似文献   

Anorexia in rainbow trout, Oncorhynchus mykiss (Walbaum), infected with Cryptobia salmositica (Sarcomastigophora: Kinetoplastida): its onset and contribution to the immunodepression     

P. T. THOMAS  P. T. K. WOO 《Journal of fish diseases》1992,15(5):443-447

  相似文献   

The digestibility of diets containing processed dried lucerne by sheep and cows     

S. THOMAS  R. C. CAMPLING 《Grass and Forage Science》1979,34(2):149-152

A series of trials was conducted to compare the digestibility of organic matter in castrated male sheep and non-lactating and lactating cows given diets containing lucerne cobs. Similar digestibility coefficients were determined when sheep and non-lactating cows were given hay and lucerne cobs, but lactating cows digested diets of hay, lucerne cobs and concentrates less well than sheep. It is concluded that if sheep are used in digestibility trials with diets containing processed lucerne and concentrates intended for milking cows, appreciable errors of prediction of digestibility of organic matter may arise.  相似文献   

Lymphocystis disease in captive barramundi     

M PEARCE  JD HUMPHREY  AD HYATT  LM WILLIAMS 《Australian veterinary journal》1990,67(4):144-145

  相似文献