Relationship Between Growth and Mycotoxin Production by Fusarium species, Biocides and Environment     

N. Magan  R. Hope  A. Colleate  E.S. Baxter 《European journal of plant pathology / European Foundation for Plant Pathology》2002,108(7):685-690

Fusarium head blight of cereals has, in recent years, become one of the most important pre-harvest diseases worldwide. This paper examines the in vitro efficacy of fungicides to control Fusarium species in cereals and the efficacy in the field on both Fusarium infection of ripening ears as well as their impact on mycotoxin production. Field studies suggest that fungicides such as tebuconazole and metconazole give good control of both Fusarium infection of ears and control of deoxynivalenol (DON) production. However, azoxystrobin and related fungicides are less effective, and grain from treated crops has sometimes been found to have increased concentrations of DON and nivalenol. Studies of isolates of Fusarium culmorum from different parts of Europe showed that complex interactions occur between environmental factors, fungicide type and isolate in relation to growth inhibition and DON production. These studies confirmed the ineffectiveness of azoxystrobin and suggest that environmental stress factors, particularly water availability and temperature, and low fungicide doses may stimulate mycotoxin production by Fusaria in vitro and in wheat grain.  相似文献   

Co-stimulation and modulation of the ensuing immune response   总被引：4，自引：0，他引：4  

Howard CJ  Hope JC  Stephens SA  Gliddon DR  Brooke GP 《Veterinary immunology and immunopathology》2002,87(3-4):123-130

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Mycobacterium paratuberculosis heat shock protein 70 as a tool in control of paratuberculosis     

Langelaar M  Koets A  Müller K  van Eden W  Noordhuizen J  Howard C  Hope J  Rutten V 《Veterinary immunology and immunopathology》2002,87(3-4):239-244

Paratuberculosis in cattle is a chronic intestinal disease in which a distinctive cellular reactivity of a Th1-type preceeds the phase in which antibody titers are easily detectable and the animal becomes clinically ill. During infection with Mycobacterium avium ssp. paratuberculosis (M.a.p), a decrease in CD4 T-helper cells has been observed in the clinical phase. Our ultimate aim is to elicit a cytotoxic reaction against infected macrophages, using recombinant Hsp70 (rHsp70) of M.a.p. as a tool to shuttle antigen into the MHC class I antigen presentation pathway. To investigate the mechanism of rHsp70 as a carrier for antigen into the cell, we studied the interaction between APC and Fitc-labelled rHsp70, using FACS analysis and confocal microscopy. Interaction of rHsp70 with the cell surface of bovine APC, presumably via a receptor, was shown on monocytes, monocyte derived macrophages and dendritic cell (DC). The interaction is detectable on the complete population of freshly derived monocytes, although peak intensity of fluorescence is lower on these cells than on macrophages and DCs. DCs show interaction on a high percentage of the cells, with high intensity, while in the case of macrophages only a subpopulation interacts with rHsp70. Efficient uptake of rHsp70 as compared to OVA is shown. Preincubation of DC with unlabelled rHsp70 leads to a decreased interaction with rHsp70-FITC. DC interacting with rHsp70 in addition showed high expression of MHC I, MHC II, Myd-1 (CD172a) and CD40. Further research will focus on loading of the rHsp70 with M.a.p. antigen for presentation in MHC class I.  相似文献   

Problèmes relatifs à la formulation des pesticides pour les pulvérisations à ultra-bas volume     

J.N. Hope 《EPPO Bulletin》1971,1(2):95-96

Après une étude des différents facteurs qui influent sur la mise au point de bonnes formulations ULV de pesticides, l'auteur souligne l'importance du choix judicieux des supports huileux et de l'incorporation des matières actives, et met en garde contre les aléas des formulations « sur place >>. L'emploi de pulvérisateurs capables de produire des gouttelettes de dimension bien définie s'impose également.  相似文献   

Phosphorous (P) deficiency due to low P availability in fishmeal produced from blue whiting (Micromesistius poutassou) in feed for under-yearling Atlantic salmon (Salmo salar) smolt     

S. Albrektsen  B. Hope  A. Aksnes 《Aquaculture (Amsterdam, Netherlands)》2009,296(3-4):318-328

Seawater transferred under-yearling Atlantic salmon (120 g) were fed a practical fishmeal formulated diet containing 57.4% blue whiting fishmeal and providing 15 g kg^− 1 total phosphorous (P) in the diet. The basal diet was supplemented with graded dietary levels of inorganic P (0, 3, 6, 9, 12 and 15 g kg^− 1) to total P levels of 15, 18, 21, 24, 27 and 30 g kg^− 1. Within a feeding period of 12 weeks, classical signs of P deficiency developed in Atlantic salmon fed the P un-supplemented diet containing 15 g kg^− 1 total P of natural origin. Deficiency signs included reduced growth and feed efficiency, reduced tissue mineral concentration (P, Ca, Mg, Zn), increased P:Ca ratio in the body, increased condition factor, metabolic disorder as indicated by lipid accumulation and impaired protein utilization, as well as reduced lipid, energy and Zn digestibility. Supplementation of inorganic P-salts in the diet at 3 g kg^− 1 (18 g kg^− 1 total P) significantly improved the production results with respect to growth and feed efficiency, and restored all other signs of P deficiency in fish. A higher supplementation level of 6 g kg^− 1 inorganic P (21 g kg^− 1 total P) was required for optimal mineralization in whole body and vertebrae. The highest supplementation levels of 15 g kg^− 1 added inorganic P (30 g kg^− 1 total P) seemed to increase P excretion and to have slightly negative impacts on growth and bone mineralization. Results suggest that P availability from blue whiting fishmeal is very low (3.2 g kg^− 1) and inadequate to meet dietary P requirement in rapidly growing under-yearling salmon immediately following seawater transfer, despite high natural P content in the blue whiting fishmeal.  相似文献   

Behavioural thermoregulation and bioenergetics of riverine smallmouth bass associated with ambient cold‐period thermal refuge          下载免费PDF全文

Jacob T. Westhoff  Craig Paukert  Sarah Ettinger‐Dietzel  Hope Dodd  Michael Siepker 《Ecology of Freshwater Fish》2016,25(1):72-85

Smallmouth bass in thermally heterogeneous streams may behaviourally thermoregulate during the cold period (i.e., groundwater temperature greater than river water temperature) by inhabiting warm areas in the stream that result from high groundwater influence or springs. Our objectives were to determine movement of smallmouth bass (Micropterus dolomieu) that use thermal refuge and project differences in growth and consumption among smallmouth bass exhibiting different thermal‐use patterns. We implanted radio transmitters in 29 smallmouth bass captured in Alley Spring on the Jacks Fork River, Missouri, USA, during the winter of 2012. Additionally, temperature archival tags were implanted in a subset of nine fish. Fish were tracked using radio telemetry monthly from January 2012 through January of 2013. The greatest upstream movement was 42.5 km, and the greatest downstream movement was 22.2 km. Most radio tagged fish (69%) departed Alley Spring when daily maximum river water temperature first exceeded that of the spring (14 °C) and during increased river discharge. Bioenergetic modelling predicted that a 350 g migrating smallmouth bass that used cold‐period thermal refuge would grow 16% slower at the same consumption level as a fish that did not seek thermal refuge. Contrary to the bioenergetics models, extrapolation of growth scope results suggested migrating fish grow 29% more than fish using areas of stream with little groundwater influence. Our results contradict previous findings that smallmouth bass are relatively sedentary, provide information about potential cues for migratory behaviour, and give insight to managers regarding use and growth of smallmouth bass in thermally heterogeneous river systems.  相似文献   

The Baby Boom and Nonmetropolitan Population Change, 1975‐1990     

Peter B. Nelson  James P. Nicholson  E. Hope Stege 《Growth and change》2004,35(4):525-544

ABSTRACT Both economic and demographic contexts influence aggregate migration streams at the regional scale. The influence of demographic and economic context on aggregate migration at the nonmetropolitan scale, however, remains unstudied. This paper presents analysis based on 1980 and 1990 Public Use Microdata Sample (PUMS) data related to age cohort effects on nonmetropolitan population change. The analysis provides enhanced understanding of how demographic factors like the baby boom might influence population movements into and out of nonmetropolitan regions. Using modified age‐cohort decomposition techniques, the analysis demonstrates how the fluctuations in nonmetropolitan population growth between 1975 and 1990 are tied to the differential migration flows of the peak baby boom years (those born between 1955 and 1964). The analysis further demonstrates how fluctuations in nonmetropolitan population growth across regions are tied to migration flows of these baby boomers. Significant variation remains within regions.  相似文献   

Characterisation of antibodies to bovine Toll-like receptor (TLR)-2 and cross-reactivity with ovine TLR2     

Kwong LS  Parsons R  Patterson R  Coffey TJ  Thonur L  Chang JS  Russell G  Haig D  Werling D  Hope JC 《Veterinary immunology and immunopathology》2011,139(2-4):313-318

Host recognition of conserved pathogen-associated molecular patterns (PAMPs) and their interactions with pattern-recognition receptors, including the Toll-like receptors (TLR) is essential for innate immune response induction. The TLR1 family (TLR1, 2, 6 and 10) is involved in the recognition of gram-positive and gram-negative bacteria and heterodimers of TLR1 or TLR6 with TLR2 are crucial for the identification of several PAMPs. Studies on cell surface expression of TLR in ruminants are hampered by the lack of specific antibodies and no convincingly cross-reactive anti-human antibodies have been described so far. We describe herein four antibodies which recognise bovine TLR2. Differences in TLR2 expression were evident on bovine antigen presenting cells with high level expression on peripheral blood monocytes and monocyte-derived macrophages. Lower levels of expression were evident on dendritic cell populations derived in vitro and ex vivo, and on alveolar macrophages. One of the antibodies recognised TLR2 expression on ovine peripheral blood monocytes. The identification of antibodies specific for bovine and ovine TLR2 will facilitate studies of the role of this important PRR in the initiation of immune responses to important pathogens.  相似文献   

Blood gas analysis and cooximetry in retired racing Greyhounds     

Sara Zaldivar‐Lopez DVM  MS  Hope K. Chisnell DVM  C. Guillermo Couto DVM  DACVIM  Nicole Westendorf‐Stingle RVT  Liliana M. Marin DVM  Maria C. Iazbik DVM  Edward S. Cooper VMD  MS  DACVECC  Maxey L. Wellman DVM  MS  PhD  DACVP  William W. Muir III DVM  MS  PhD  DACVA  DACVECC 《Journal of Veterinary Emergency and Critical Care》2011,21(1):24-28

Objective – The purposes of this study were to evaluate the oxygen affinity of hemoglobin (Hb) in healthy retired racing Greyhounds via cooximetry, and to establish reference intervals for blood gases and cooximetry in this breed. Design – Prospective clinical study. Setting – University Teaching Hospital. Animals – Fifty‐seven Greyhounds and 30 non‐Greyhound dogs. Interventions – Venous blood samples were collected from the jugular vein and placed into heparinized tubes. The samples were analyzed within 30 minutes of collection using a blood gas analyzer equipped with a cooximeter. Measurements and Main Results – Greyhounds had significantly higher pH, PO₂, oxygen saturation, oxyhemoglobin, total Hb, oxygen content, and oxygen capacity and significantly lower deoxyhemoglobin and P₅₀ when compared with non‐Greyhound dogs. Conclusion – These findings support the fact that this breed is able to carry a higher concentration of total oxygen in the blood. As reported previously, this breed also has lower P₅₀ and, therefore, high oxygen affinity. In light of recent findings suggesting that in certain tissues a high affinity for oxygen is beneficial, this adaptation may be of benefit during strenuous exercise.  相似文献   

A national programme for mastitis control in Australia: Countdown Downunder     

PB Brightling  RD Dyson  AF Hope  J Penry 《Irish veterinary journal》2009,62(Z4):S52

In 1998, Countdown Downunder, Australia's national mastitis and cell count control programme, was created. With funding from the country's leading dairy organisation, Dairy Australia, this programme was originally intended to run for three years but is now in its tenth year. As it was the first time Australia had attempted a national approach to mastitis control on the farm, the first three years of the programme were largely concerned with the development of resources to be used by farmers and service providers. The second three years were devoted to training with both groups. Since that time, Countdown Downunder has entered into a second resource development phase. The goal of the programme was to achieve a reduction in the bulk milk somatic cell count from the Australian dairy herd. To achieve this, the programme had to develop resources with clear and consistent messages around mastitis and somatic cell count control on farms. It was determined that progress toward the goals would be made more rapidly if service providers were trained in the use of these resources prior to farmers. This paper reviews the Countdown Downunder programme from 1998 to 2007.  相似文献