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1.
Luuk B. Schoonman T. Wilsmore Emmanuel S. Swai 《Tropical animal health and production》2010,42(4):579-587
In view of the worldwide importance of Toxoplasma gondii and the fragmented information on the seroprevalence of the disease in animals in Tanzania, a study, using the modified Eiken
latex agglutination test (LAT), was conducted from May 2003 to January 2004 to determine the prevalence of antibody to T. gondii in 130 randomly selected farms comprising 655 cattle. The overall seroprevalence of T.gondii antibodies in cattle and farms were 3.6% and 13%, respectively. Risk factors for animal and herd-level toxoplasmosis seropositivity
were tested using multivariable logistic regression to control for confounding factors. Cattle managed under traditional husbandry
practises were more likely to be seropositive than those managed under smallholder practises (48% versus 4.7%; p < 0.01). Herd size of ≥ 9 cattle were at greater risk of acquiring infection than herds holding fewer animals [≤ 9 cattle],
(odd ratio [OR] = 3.99; 95% confidence interval [CI], 0.97–16.48; P = 0.001). We concluded that seroprevalence at herd level was high and relatively low at animal level, possibly due to the
reduced susceptibility of cattle to T.gondii infection as compared to goats and sheep. The high seroprevalence in animals managed by traditional husbandry practise suggests
that the parasite is widely distributed in the environment and could pose a public health threat to the people living in those
areas. 相似文献
2.
Isaurinda Baptista Brian Irvine Luuk Fleskens Violette Geissen Coen Ritsema 《Land Degradation \u0026amp; Development》2016,27(7):1679-1690
Field trials have demonstrated the potential of soil conservation technologies but have also shown significant spatial–temporal yield variability. This study considers the Pan‐European Soil Erosion Risk Assessment – Desertification Mitigation Cost‐Effectiveness modelling approach to capture a greater range of climatic conditions to assess the potential effect of an improved agricultural management practice emerged from field trials as a promising strategy for enhancing food security and reducing soil and land degradation. The model considers the biophysical and socio‐economic benefits of the improved soil conservation technique (T3) – residue mulch combined with pigeon pea hedges and an organic amendment, against a local baseline practice (T0). The historic rainfall statistics and 50‐year rainfall realizations provide a unique time series of rainfall and an envelope of the potential crop yield. Envelopes of potential biomass production help express the agricultural risk associated with climate variability and the potential of the conservation measures to absorb the risk, highlighting the uncertainty of a given crop yield being achieved in any particular year. T3 elevates yield under both sub‐humid and semi‐arid climates with greater security for sub‐humid areas even though risk of crop failure still exists. The technology offered good potential to increase yields by 20% in 42% of the dryland area in Santiago Island and reduce erosion by 8·6 Mg ha−1, but in terms of cost‐effectiveness, it might be prohibitively expensive for farmers lacking inputs. The findings can enable the assessment of policy options at larger scale or influence adoption of improved conservation measures under the climatic variability of the Cabo Verde drylands and resilience to future climate change. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
3.
A cross-sectional study was conducted between May 2003 and January 2004 on 130 households and 655 (246 indigenous and 409
crossbred) cattle to determine the prevalence of bovine tuberculosis (bTB) and assess risk factors associated with prevalence
in smallholder dairy and traditionally managed herds in the Tanga region of North-eastern Tanzania. Random sampling, single
intradermal tuberculin (SIT), comparative intradermal tuberculin (SCIT) tests and a questionnaire were used to gather individual
animal and herd level information. From 642 animal tested by SIT, 35 (5.4%) were positive reactors for tuberculosis. Out of
those 35 bTB positive reactors, eight (1.25%) proved to be positive reactors for tuberculosis upon further testing by SCIT.
Based on the SCIT test, individual animal prevalences of bTB in the smallholder dairy and traditionally managed cattle was
2% and 0%, respectively. The corresponding overall herd prevalence was 5.7% and 0%, respectively. In conclusion, bTB prevalence
seems low; however, its potential risk to public health is of concern; underscoring the need for further research, active
surveillance to better understand the epidemiology of the disease in different cattle production systems in Tanzania. 相似文献
4.
5.
A Stringent and Broad Screen of Solanum spp. tolerance Against Erwinia Bacteria Using a Petiole Test
Hendrik Rietman Richard Finkers Luuk Evers Patricia S. van der Zouwen Jan M. van der Wolf Richard G. F. Visser 《American Journal of Potato Research》2014,91(2):204-214
Blackleg and stem rot caused by coliform bacteria belonging to Dickeya spp. and Pectobacterium spp. (both referred to as Erwinia in this paper) are a problem for potato growers worldwide and no sources of high tolerance are currently present in the cultivated S. tuberosum gene pool. To find sources of tolerance, 532 genotypes from 340 accessions, covering most of the known potato species, were assayed with P. wasabiae, P. carotovorum and D. ‘solani’ species in a petiole test. This petiole test was optimized later on using well responding genotypes from the broad screen. Based on the obtained data, the best developmental stage for cell wall degradation tests was identified to be the 4th-6th youngest leaf. Under the stringent biotic and climatic screening conditions used, only three genotypes were regarded as tolerant against all tested Erwinia species. These genotypes all belonged to the series Yungasensa, this series can be readily crossed with cultivated potato and is considered as a genetic source to upgrade the Erwinia tolerance level of cultivated potato. 相似文献
6.
Mingxia Wang Yuanpeng Wang Wenfeng Tan Fan Liu Xionghan Feng Luuk K. Koopal 《Journal of Soils and Sediments》2010,10(5):879-885
Purpose
Oxides are ubiquitous in nature and play an important role in scavenging metal ions from soils and sediments. At the common pH range of the natural environment the well-studied Fe and Al oxides mostly carry a positive charge and adsorbed amounts of heavy metals, and their desorption percentages decrease with increasing ionic strength. The less well studied but also important Mn oxides possess negative charges in the natural environment and this will lead to a different behavior. Therefore, it is useful to further investigate how the electrolyte concentration and type affect the metal ion adsorption/desorption by Mn oxides. 相似文献7.
Assessment of protective efficacy of live and killed vaccines based on a non-encapsulated mutant of Streptococcus suis serotype 2. 总被引：4，自引：0，他引：4
Henk J Wisselink Norbert Stockhofe-Zurwieden Luuk A T Hilgers Hilde E Smith 《Veterinary microbiology》2002,84(1-2):155-168
The protective efficacy of a live and killed non-encapsulated isogenic mutant of Streptococcus suis serotype 2 was determined in pigs, and compared with the efficacy of the capsulated wild-type strain. SPF pigs were vaccinated twice intramuscularly at 4 and 7 weeks of age with a dose of 1 x 10(9) formalin-killed CFU of the wild-type (WT-BAC), formalin-killed non-encapsulated mutant (CM-BAC) or live non-encapsulated mutant (CM-LIVE) strain. After 2 weeks, vaccinated pigs and non-vaccinated controls were challenged intravenously with 1 x 10(7) CFU of the homologous, wild-type S. suis serotype 2 strain. Protection was evaluated by clinical, bacteriological, serological and post-mortem examinations. All pigs vaccinated with WT-BAC were completely protected against challenge with the homologous serotype. Pigs vaccinated with CM-BAC were partially protected. Although all pigs vaccinated with CM-BAC survived the challenge, four out of five pigs developed clinical signs of disease for several days. Compared to the WT-BAC and CM-BAC, the CM-LIVE vaccine was less protective. Two out of five pigs vaccinated with CM-LIVE died in the course of the experiment and all of them developed specific clinical signs of disease for several days. The protective efficacy of the vaccines could be associated with serum antibody titers. Antibody titers against cells of wild-type and non-encapsulated mutant strains as well as against muramidase-released proteins (MRP) were high in pigs vaccinated with WT-BAC and CM-BAC. Pigs vaccinated with CM-LIVE showed lower antibody titers. Antibody titers against purified capsular polysaccharides (CPS) of S. suis serotype 2 were only found in pigs vaccinated with WT-BAC. These findings indicate that CPS and other bacterial components of WT-BAC are probably essential for full protection against homologous challenge. 相似文献
8.
Oliver Jancke Luuk K.A. Dorren Frédéric Berger Marc Fuhr Michael Köhl 《Forest Ecology and Management》2009
Coppice forest stands can play a key protective role on active rockfall slopes in mountainous regions. This paper aims at quantifying their protection function and at explaining the role of different stand parameters in this function. To achieve these objectives we first made field inventories focussing on the dendrometric and spatial characteristics of 13 coppice stands. Then, we developed a 2D simulation model, called RockCop, to quantify their protective function against rockfall. The simulations show that the predominant size of the falling rocks conditions which of the dendrometric stand parameters mainly determine the protective function of a coppice stand. In the case of small rocks (20 cm Ø), we conclude that a higher stand density improves the protective function. Thus, for those rocks, young stands are most adequate. An acceptable level of protection against medium-sized rocks (50 cm Ø) is only fulfilled by few coppice stands and determined by specific combinations of stand density, stem diameters, basal area and species composition. None of the investigated stands offer sufficient protection against large rocks (1 m Ø). 相似文献
9.
Chen Hao Fleskens Luuk Schild Johanna Moolenaar Simon Wang Fei Ritsema Coen 《Landscape Ecology》2022,37(1):329-346
Landscape Ecology - From 1999 onwards, China has initiated a large-scale landscape restoration project in the Chinese Loess Plateau, which has had profound but variable impacts on the local... 相似文献
10.
J. Perkins M. Reed L. Akanyang J. Atlhopheng R. Chanda L. Magole W. Mphinyane K. Mulale R. Sebego L. Fleskens B. Irvine M. Kirkby 《Land Degradation \u0026amp; Development》2013,24(5):463-477
It is increasingly recognised that tackling land degradation through more sustainable land management depends on incorporating multiple perspectives by using a variety of methods at multiple scales, including the perspectives of those who manage and/or use the land. This paper reports experience implementing a previously proposed methodological framework that is designed to facilitate knowledge sharing between researchers and stakeholders about land degradation severity and extent, and sustainable land management options. Empirical findings are presented from the Botswana site of the EU‐funded Desertification Mitigation and Remediation of Land project. The paper reflects upon the challenges and benefits of the proposed framework and identifies a number of benefits, notably related to insights arising from the integration of local and scientific knowledge, and the ownership of the sustainable land management strategies that emerged from the process. However, implementing the framework was not without challenges, and levels of poverty and formal education may limit the implementation of the framework in some developing world contexts. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献