Gastrointestinal nematode control practices on lowland sheep farms in Ireland with reference to selection for anthelmintic resistance     

Patten T  Good B  Hanrahan JP  Mulcahy G  de Waal T 《Irish veterinary journal》2011,64(1):4-6

Gastrointestinal parasitism is a widely recognised problem in sheep production, particularly for lambs. While anthelmintics have a pivotal role in controlling the effects of parasites, there is a paucity of data on how farmers use anthelmintics. A representative sample of Irish lowland farmers were surveyed regarding their parasite control practices and risk factors that may contribute to the development of anthelmintic resistance. Questionnaires were distributed to 166 lowland Irish sheep producers. The vast majority of respondents treated their sheep with anthelmintics. Lambs were the cohort treated most frequently, the majority of farmers followed a set programme as opposed to treating at sign of disease. A substantial proportion (61%) administered four or more treatments to lambs in a 'normal' year. Departures from best practice in anthelmintic administration that would encourage the development of anthelmintic resistance were observed. In conclusion, in the light of anthelmintic resistance, there is a need for a greater awareness of the principles that underpin the sustainable use of anthelmintics and practices that preserve anthelmintic efficacy should be given a very high priority in the design of helminth control programmes on each farm. To this end, given that veterinary practitioners and agricultural advisors were considered to be the farmer's most popular information resource, the capacity of these professions to communicate information relating to best practice in parasite control should be targeted.  相似文献   

Molecular markers assist in the development of diverse inbred backcross lines in European Long cucumber (<Emphasis Type="Italic">Cucumis sativus</Emphasis> L.)     

Isabelle Y. Delannay  Jack E. Staub 《Euphytica》2011,178(2):229-245

The popular fresh-market European Long cucumber (Cucumis sativus L.) is grown commercially worldwide under controlled, greenhouse environments. However, it has a narrow genetic base, where private and public improvement programs can trace their origins to comparatively few accessions. Therefore, a project was designed to identify diverse genotypes for use in the formation and analysis of inbred backcross (BC₂S₃) lines (IBL) to broaden the genetic base of this market class. Initially, 42 cucumber accessions were evaluated with a previously defined standard marker array to identify parents for use in backcrossing. The IBL were developed by crossing the elite commercial line NZ1 (Nunhems Vegetable Seeds, Haelen, The Netherlands) and PI 432858 (China), and then backcrossing the most genetically diverse BC₁ and BC₂ progeny to the elite parent as defined by marker analyses (19 polymorphic, mapped SSR, and SCAR marker loci), followed by three generations of single seed descent resulting in 116 IBL (BC₂S₃). The IBL were evaluated under greenhouse conditions for days to anthesis, sex expression, lateral branch number, yield, and exterior fruit quality in Madison, Wisconsin, USA (soil media), and in Haelen and Bergschenhoek, The Netherlands (soilless, hydroponic media). The IBL were genotyped using an expanded marker array (37 polymorphic SSR, SCAR, SNP, EST, BAC end, and gene-associated loci), and genetic relationships were examined by multivariate analyses using phenotypic and genotypic data. The 116 developed IBL possessed considerable morphological and genotypic diversity, where genetic distance (GD) among lines ranged between 0.00 and 0.77. These IBL possessed many commercially acceptable attributes, and, thus, genetic diversity in this market type could be substantially increased by the use of these genetically broad-based IBL during plant improvement.  相似文献   

Inflammatory blockade restores adult hippocampal neurogenesis   总被引：1，自引：0，他引：1  

Monje ML  Toda H  Palmer TD 《Science (New York, N.Y.)》2003,302(5651):1760-1765

Cranial radiation therapy causes a progressive decline in cognitive function that is linked to impaired neurogenesis. Chronic inflammation accompanies radiation injury, suggesting that inflammatory processes may contribute to neural stem cell dysfunction. Here, we show that neuroinflammation alone inhibits neurogenesis and that inflammatory blockade with indomethacin, a common nonsteroidal anti-inflammatory drug, restores neurogenesis after endotoxin-induced inflammation and augments neurogenesis after cranial irradiation.  相似文献   

Comparison of individual assignment methods and factors affecting assignment success in cattle breeds using microsatellites     

Seblewengel B. Talle  Erling Fimland  Ola Syrstad  Theo Meuwissen  Helge Klungland 《Acta Agriculturae Scandinavica, Section A - Animal Sciences》2013,63(2-3):74-79

Abstract

Comparisons of seven different individual assignment methods based on likelihood and distances were carried out with four different sets of data, which varied both in number of populations and genetic divergence. Based on 27 microsatellites genotyped in eight cattle breeds (Icelandic and seven Norwegian), 28 hybrid populations were simulated. Factors affecting individual assignment success, such as number and divergence of populations, sample size and number of loci, were assessed from actual and simulated data. The Bayesian, frequency and Nei-minimum methods performed more or less similarly. Individual assignment success depended mainly on population number and divergence (F_ST). Higher success was observed at high level of divergence among populations and at low number of source populations considered. With eight pure breeds and 27 loci considered the assignment success rate ranged from 55 to 70%. Generally, assignment success increased with increasing number of loci and/or sample size.  相似文献   

Characterisation of Phytophthora infestans Isolates Collected from Potato and Tomato Crops in Tunisia During 2006–2008     

Kalthoum Harbaoui  Theo van der Lee  Vivianne G. A. A. Vleeshouwers  Nouri Khammassy  Moncef Harrabi  Walid Hamada 《Potato Research》2013,56(1):11-29

Severe late blight epidemics in Tunisia in recent years prompted population studies on the pathogen responsible for this disease, Phythophthora infestans. Characterisation of 165 Tunisian P. infestans isolates collected from 2006 to 2008 was performed for the mating type and mt haplotype, while subsets were analysed for metalaxyl sensitivity (n?=?65), virulence on differential set of 11 R genes of Solanum demissum (n?=?31), aggressiveness on cv. Bintje (n?=?36) and measurement of the radial growth on agar medium at three temperatures (n?=?38). Most isolates from potato and all isolates from tomato had the A1 mating type. The A2 mating type was detected in the north-east and northern areas, but not in the north-west. All the A2 mating type isolates were metalaxyl resistant and seem to be part of a new generation of the P. infestans isolates which are more aggressive, with more complex races, and tolerant to higher temperatures. The increased severity of epidemics during 2006 to 2008 can be attributed to favourable weather conditions during growing seasons, adaptation of new genotypes, widespread phenylamide resistance in potato production regions and most probably incorrect spray programmes. In contrast to the presence of complex pathotypes in two major potato crop regions (north-east and northern areas), the P. infestans population detected in the other regions and in tomato crops was still relatively simple. Compared with the situation in Europe and the American continent, or even compared with neighbouring countries such as Algeria, the genetic changes in Tunisia are still comforting and require strict management decision on late blight control to avoid the spread of new P. infestans populations from Europe or neighbouring countries.  相似文献   

RESEARCH PAPER: Comparison of two different methods for physiologic dead space measurements in ventilated dogs in a clinical setting     

Martina Mosing  Lukas Staub  Yves Moens 《Veterinary anaesthesia and analgesia》2010,37(5):393-400

ObjectiveTo compare physiologic dead space (V_D) and physiologic dead space to tidal volume (V_T) ratio (V_D/V_T) obtained by an automated single breath test for carbon dioxide (CO₂) (method SBT) and a manual calculation (method MC) in ventilated healthy dogs.Study designProspective clinical study.AnimalsTwenty client‐owned dogs, ASA I and II undergoing anaesthesia for clinical purposes.MethodsFollowing pre‐medication, induction of anaesthesia, and intubation of the trachea, intermittent positive pressure ventilation was commenced. Mixed expired CO₂ partial pressure (PēCO₂) was measured by two methods: method MC by analysis, using an infrared capnograph, of the expired gas collected in a mixing box and method SBT which calculated it automatically by a device consisting of a mainstream capnograph and a pneumotachograph. At four time points arterial partial pressure of CO₂ (PaCO₂) was measured. Physiologic dead space variables (V_D and V_D/V_T) were calculated manually (method MC) or automatically (method SBT) using the Bohr–Enghoff equation.Method MC and SBT were compared using Bland–Altman plots and linear regression. Intra‐class correlation coefficient (ICC) was used to measure consistency of each method.ResultsFour measurement pairs were obtained in all 20 dogs for method SBT and MC. The bias was ?1.15 mmHg, 7.97 mL and 0.02 for PēCO₂, V_D and V_D/V_T, respectively. Linear regression analysis revealed a correlation coefficient (r²) of 0.79, 0.94, and 0.83 for PēCO₂, V_D and V_D/V_T, respectively. The ICC revealed an excellent consistency for both methods.ConclusionsThe single breath test (SBT) can be used for clinical evaluation of V_D and V_D/V_T in anaesthetized ventilated dogs.Clinical relevanceThrough measuring V_D and V_D/V_T important information about lung ventilation can be obtained and the SBT is an easy method to use for this purpose.  相似文献   

Inheritance of beta-carotene-associated flesh color in cucumber (<Emphasis Type="Italic">Cucumis sativus</Emphasis> L.) fruit     

H. E. Cuevas  H. Song  J. E. Staub  P. W. Simon 《Euphytica》2010,171(3):301-311

The nutritional value of cucumber (Cucumis sativus L.) can be improved by the introgression of β-carotene (i.e., provitamin A and/or orange flesh) genes from “Xishuangbanna gourd” (XIS; Cucumis sativus var. xishuangbannanesis Qi et Yuan) into US pickling cucumber. However, the genetics of β-carotene content has not been clearly defined in this US market type. Thus, three previous populations derived from a US pickling cucumber (‘Addis’) × XIS mating were evaluated for β-carotene content, from which the high β-carotene inbred line (S₄), ‘EOM 402-10’, was developed. A cross was then made between the US pickling cucumber inbred line ‘Gy7’ [gynoecious, no β-carotene, white flesh; P₁] and ‘EOM 402-10’ [monoecious, possessing β-carotene, orange flesh; P₂] to determine the inheritance of β-carotene in fruit mesocarp and endocarp tissue. Parents and derived cross-progenies (F₁, F₂, BC₁P₁, and BC₁P₂) were evaluated for β-carotene content in a greenhouse in Madison, Wisconsin. While F₁ and BC₁P₁ progeny produced mature fruits possessing white, light-green, and green (0.01–0.02 μg g⁻¹ β-carotene) mesocarp, the F₂ and BC₁P₂ progeny mesocarp segregated in various hues of white, green, yellow (0.01–0.34 μg g⁻¹ β-carotene), and orange (1.90–2.72 μg g⁻¹ β-carotene). Mesocarp and endocarp F₂ segregation adequately fit a 15:1 [low-β-carotene (0.01–0.34 μg g⁻¹): high-β-carotene (1.90–2.72 μg g⁻¹)] and 3:1 (low-β-carotene: high-β-carotene) ratio, respectively. Likewise, segregation of carotene concentration in mesocarp and endocarp tissues in BC₁P₂ progeny adequately fit a 3:1 (low-β-carotene: high-β-carotene) and 1:1 (low-β-carotene: high-β-carotene) ratio, respectively. Progeny segregations indicate that two recessive genes control the β-carotene content in the mesocarp, while one recessive gene controls β-carotene content in the endocarp. Single marker analysis of F₂ progeny using the carotenoid biosynthesis gene Phytoene synthase determined that there was no association between this gene and the observed β-carotene variation in either fruit mesocarp or endocarp.  相似文献   

Development of fine-leaved Festuca grass populations identifies genetic resources having improved forage production with potential for wildfire control in the western United States     

Matthew D. Robbins  Jack E. Staub  B. Shaun Bushman 《Euphytica》2016,207(2):377-385

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Modelling Sonchus arvensis root biomass allocation to below-ground shoot and fine root growth     

Bengt Torssell  Henrik Eckersten  Theo Verwijst 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2016,66(6):476-482

Below-ground (bg) shoot emergence rates of Sonchus arvensis are dependent on temperature and root weight. However, it is unknown to what extent this is due to a root depletion rate that depends on initial root weight, or due to differences in resource allocation to fine root and bg shoot growth. To resolve this, we retrieved data from an experiment in which plants were grown in the dark at constant temperature (4°C, 8°C, and 18°C) and harvested prior to or at shoot emergence. A dynamic mass-balance model, in which biomass of the initial root was allocated to bg shoot and fine root daily growth, and where respiration took place from all tissues, was used. The relative depletion rate of root biomass (RDR; d^?1) and fraction of the depleted biomass allocated to bg shoots (SFRR) were estimated and calibrated to observed biomass. The RDR increased with initial root weight and temperature and SFFR was highest for light roots and lowest for heaviest roots, whereas the rest was allocated to fine root biomass. The length-to-biomass ratio of bg shoots decreased with initial root weight. Under between-year weather variations (2004–2010), the reduction in root biomass during the coldest April–May was simulated to be over 12 days delayed compared with the warmest spring. The influence of biomass allocation on bg shoot elongation of heavier roots was thus stimulated by a larger fraction of root biomass being depleted, but counteracted by a smaller fraction of it allocated into bg shoot elongation, compared with lighter roots. The complexity of shoot emergence based on root depletion estimates may be a reason why predictions based on only an accumulated root weight-specific temperature sum, as proposed by a previous study, are expected to be less uncertain than those based on root depletion estimates.  相似文献   

Clinicopathologic Observations on Laryngoplasty Failure in a Horse     

Michael Robert Hardcastle BVSc  Frederik Ekhart Theo Pauwels DVM  Diplomate ACVS  Mark Grey Collett BVSc  MMedVet  MEd 《Veterinary surgery : VS》2012,41(5):649-653

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