共查询到20条相似文献,搜索用时 11 毫秒
1.
Christelle Robinet Nico Van Opstal Richard Baker Alain Roques 《Biological invasions》2011,13(12):2981-2995
Pine wilt disease, which can rapidly kill pines, is caused by the pine wood nematode, Bursaphelenchus xylophilus. It is expanding its range in many countries in Asia and measures are being taken at the EU level to prevent its spread from
Portugal. Due to the threat to European forests, it is important to prevent additional introductions and target surveillance
to the points of entry that pose the greatest risk. In this study, we present a model to identify the European ports from
which the nematode can spread most rapidly across Europe. This model describes: (1) the potential spread of the pine wood
nematode based on short-distance spread (the active flight of the vector beetles) and long-distance spread (primarily due
to human-mediated transportation), and (2) the development of pine wilt disease based on climate suitability and the potential
spread of the nematode. Separate introductions at 200 European ports were simulated under various climate change scenarios.
We found that the pine wood nematode could invade 19–60% of the study area (30°00 N–72°00 N, 25°00 W–40°00 E) by 2030, with
the highest spread from ports located in Eastern and Northern Europe. Based on climate change scenarios, the disease could
affect 8–34% of the study area by 2030, with the highest spread from ports located in South-Eastern Europe. This study illustrates
how a spread model can be used to determine the critical points of entry for invasive species, so that surveillance can be
targeted more accurately and control measures prioritised. 相似文献
2.
Chun Yan Wang Can Yin Zhe Ming Fang Zhen Wang Yun Bo Wang Jian Jie Xue 《Biocontrol Science and Technology》2018,28(3):268-277
The present study evaluated the protective effects of the nematophagous fungus Esteya vermicola on the large pine trees of Mt. Wora, Jinju, South Korea for six years. When pine trees were treated with E. vermicola 110 days before artificial normal pinewood nematode (PWN) infection, 30–50% of the trees survived for six years. When pine trees were treated with E. vermicola one week after artificial normal PWN infection, 40% of the trees were saved. In contrast, all of the control trees were killed by pine wilt disease in the first year. Although it has been more than six years since the beginning of this experiment, the existence of E. vermicola inside the treated pine trees was successfully detected using a PCR method with two pairs of specific primers for E. vermicola. These results suggest that E. vermicola possesses great potential as a biocontrol agent to combat the disastrous pine wilt disease. This is the first report of using nematophagous fungi to control pine wilt disease in the field for a duration of over five years. 相似文献
3.
The symptoms and causal agents of early-dying disease (Verticillium wilt) of potatoes 总被引:2,自引:0,他引:2
The only characteristic symptom produced by Verticillium albo-atrum and V. dahliae in infected potato plants is unilateral chlorosis and necrosis: this was not shown until the approach of host maturity, and was distinguishable from symptoms of natural senescence only in its slightly earlier expression. Of six species of Verticillium tested against potato (King Edward), V. albo-atrum, V. dahliae, V. nigrescens and V. nubilum were pathogenic (all produced ‘wilt’ symptoms and relative virulence was in that decreasing order) but V. tricorpus and V. lateritium did not induce disease. Isolates of V. albo-atrum and V. dahliae, obtained from a number of other host plants, were also pathogenic to potato. Possible reasons are given for the fewness of records of ‘Early dying’ disease (Verticillium wilt) of potatoes in the field. 相似文献
4.
Pine wilt disease (PWD) caused by the pine wood nematode is the most serious global threat to pine forests. Hazard ratings of trees and forests to pest attacks provide important information to efficiently identify current or future hazardous conditions. However, in spite of the importance of hazard ratings for managing PWD, there are few studies on hazard ratings in this system. In this study, we evaluated the hazard ratings of pine trees and pine stands to PWD by considering environmental factors at the level of the stand and the individual tree. Our results showed that trees with larger diameter at breast height (DBH) showed a higher risk rate than those with smaller DBH, indicating that large trees have an increased probability of exposure to vector beetles because they are tall and have a large crown volume. We also found that reduced tree vigour could be related to susceptibility to PWD. In pine stands, geographical factors showed a high correlation with the occurrence of PWD. PWD occurrence was rare at high altitudes, but was more common on steep and south-facing slopes. These patterns were consistently observed in the results from 2 computational approaches: self-organizing map (SOM) and random forest models. The combination of SOM and random forest was effective to extract ecological information from the dataset. The SOM efficiently characterized relations among variables, and the random forest model was effective at predicting ecological variables, including the hazard rating of trees to disturbances. 相似文献
5.
Katsumi Togashi 《Population Ecology》1991,33(2):245-256
To understand the mechanism of spread of pine wilt disease caused by the pinewood nematode, Bursaphelenchus xylophilus, which is vectored by a cerambycid, Monochamus alternatus, the spatial distribution of trees weakened by the nematode was examined within a Pinus thunbergii stand from June to October for 4 years. The weakened trees were distributed in a clumped pattern in 1980 and 1981, at an early stage of infestation. In many cases, they showed a double-clumped pattern. The degree of aggregation was higher in June or July than after August. They were uniformly distributed in June or July 1982 and in June 1983 whereas they showed a double-clumped pattern after August. The trees were frequently weakened in June or July when they were near the trees weakened during the previous year. At quadrat sizes of more than 25 m2, spatial overlapping was pronounced between trees weakened during June–July of the current year and those weakened in the previous year. The seasonal changes in spatial distribution of weakened trees were explained by the interaction among M. alternatus, B. xylophilus and Pinus trees. 相似文献
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7.
Katsumi Togashi 《Population Ecology》1988,30(2):177-192
Summary The seasonal occurrence ofMonochamus alternatus and newly weakened trees were investigated in aPinus thunbergii stand for 4 years. Adult beetles were present between June and September with a peak in their population occurring in early
July followed by a decline then a period of about one month being in a steady number. The average number ofBursaphelenchus xylophilus (Nematoda), which is the causal agent of pine wilt disease, within beetles decreased as the season advanced. Pine trees newly
weakened byB. xylophilus appeared between June and October, especially from August to October. The proportion of weakened or killed trees was directly
proportional to the average beetle density per tree from June to August. 相似文献
8.
Background
A logical model of the known metabolic processes in S. cerevisiae was constructed from iFF708, an existing Flux Balance Analysis (FBA) model, and augmented with information from the KEGG online pathway database. The use of predicate logic as the knowledge representation for modelling enables an explicit representation of the structure of the metabolic network, and enables logical inference techniques to be used for model identification/improvement. 相似文献9.
Arun K. Bose Arthur Gessler Andreas Bolte Alessandra Bottero Allan Buras Maxime Cailleret J. Julio Camarero Matthias Haeni Ana‐Maria Here Andrea Hevia Mathieu Lvesque Juan C. Linares Jordi Martinez‐Vilalta Luis Matías Annette Menzel Raúl Snchez‐Salguero Matthias Saurer Michel Vennetier Daniel Ziche Andreas Rigling 《Global Change Biology》2020,26(8):4521-4537
Global climate change is expected to further raise the frequency and severity of extreme events, such as droughts. The effects of extreme droughts on trees are difficult to disentangle given the inherent complexity of drought events (frequency, severity, duration, and timing during the growing season). Besides, drought effects might be modulated by trees’ phenotypic variability, which is, in turn, affected by long‐term local selective pressures and management legacies. Here we investigated the magnitude and the temporal changes of tree‐level resilience (i.e., resistance, recovery, and resilience) to extreme droughts. Moreover, we assessed the tree‐, site‐, and drought‐related factors and their interactions driving the tree‐level resilience to extreme droughts. We used a tree‐ring network of the widely distributed Scots pine (Pinus sylvestris) along a 2,800 km latitudinal gradient from southern Spain to northern Germany. We found that the resilience to extreme drought decreased in mid‐elevation and low productivity sites from 1980–1999 to 2000–2011 likely due to more frequent and severe droughts in the later period. Our study showed that the impact of drought on tree‐level resilience was not dependent on its latitudinal location, but rather on the type of sites trees were growing at and on their growth performances (i.e., magnitude and variability of growth) during the predrought period. We found significant interactive effects between drought duration and tree growth prior to drought, suggesting that Scots pine trees with higher magnitude and variability of growth in the long term are more vulnerable to long and severe droughts. Moreover, our results indicate that Scots pine trees that experienced more frequent droughts over the long‐term were less resistant to extreme droughts. We, therefore, conclude that the physiological resilience to extreme droughts might be constrained by their growth prior to drought, and that more frequent and longer drought periods may overstrain their potential for acclimation. 相似文献
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11.
Fugo Takasu 《Population Ecology》2009,51(3):399-409
Pine wilt disease is caused by the pinewood nematode Bursaphelenchus xylophilus, which is vectored by the Japanese pine sawyer beetle Monochamus alternatus. Due to their mutualistic relationship, according to which the nematode weakens and makes trees available for beetle reproduction
and the beetle in turn carries and transmits the nematode to healthy pine trees, this disease has resulted in severe damage
to pine trees in Japan in recent decades. Previous studies have worked on modeling of population dynamics of the vector beetle
and the pine tree to explore spatial expansion of the disease using an integro-difference equation with a dispersal kernel
that describes beetle mobility over space. In this paper, I revisit these previous models but retaining individuality: by
considering mechanistic interactions at the individual level it is shown that the Allee effect, an increasing per-capita growth
rate as population abundance increases, can arise in the beetle dynamics because of the necessity for beetles to contact pine
trees at least twice to reproduce successfully. The incubation period after which a tree contacted by a first beetle becomes
ready for beetle oviposition by later beetles is crucial for the emergence of this Allee effect. It is also shown, however,
that the strength of this Allee effect depends strongly on biological mechanistic properties, especially on beetle mobility.
Realistic individual-based modeling highlights the importance of how spatial scales are dealt with in mathematical models.
The link between mechanistic individual-based modeling and conventional analytical approaches is also discussed. 相似文献
12.
Population ageing is a worldwide phenomenon, most advanced in developed countries and expected to continue over the next few decades. As people are surviving longer with age-associated disease and disability, there is an imperative to identify innovative solutions for an already overburdened health care system. Such innovations need to be focused on disease management, taking into consideration the strong associations that have been established between psychosocial factors and pathophysiological mechanisms associated with chronic disease. Aside from personal and community costs, chronic diseases produce a significant economic burden due to the culmination of health care costs and lost productivity. This commentary reports on a programme of research, Translating Research, Integrated Public Health Outcomes and Delivery, which will evaluate an optimal health programme that adopts a person-centred approach and engages collaborative therapy to educate, support and improve the psychosocial health of those with chronic disease. The effectiveness of the optimal health programme will be evaluated across three of the most significant contributors to disease burden: diabetes mellitus, chronic kidney disease and stroke. Cost-effectiveness will also be evaluated. The findings derived from this series of randomised controlled trials will also provide evidence attesting to the potential applicability of the optimal health programme in other chronic conditions. 相似文献
13.
Effects of pine wilt disease invasion on soil properties and Masson pine forest communities in the Three Gorges reservoir region,China 总被引:1,自引:0,他引:1 下载免费PDF全文
Pine wilt disease (PWD) has caused significant Masson pine mortality in the Three Gorges reservoir region in central China. In this study, five uniform Masson pine stand types infected by PWD were selected and surveyed on slopes and aspects with similar environmental conditions. In sites that had been infected, soil bulk density was reduced, and the difference among the groups was statistically significant (P < 0.05) at the 0–10 cm and 10–20 cm soil layers, but not at 20–40 cm. Other soil water‐related physical properties, excluding noncapillary porosity, significantly differed among the groups in all soil layers. Additionally, the values of available phosphorus, sodium, potassium, calcium, and magnesium were higher in the invaded stands, but the total nitrogen and organic matter contents were lower. Masson pine does not become reestablished following PWD‐induced mortality but is instead replaced by broad‐leaved tree species. Among the 19 examined environmental variables, five were found to be significantly related with the ordination of plant community structure: Masson pine stumps (MPS), K+, capillary water holding capacity (CWHC), capillary porosity (CP), and soil water content (SWC). Among these factors, the plant community structure was principally related to MPS and K+. The findings of this study show that the outbreak of PWD has impacted Masson pine forest soil properties and altered forest community composition. The disease is negatively related with the presence of Masson pine and positively associated with that of broad‐leaved tree species. 相似文献
14.
Block R Kakinami L Liebman S Shearer GC Kramer H Tsai M 《Prostaglandins, leukotrienes, and essential fatty acids》2012,86(4-5):175-182
IntroductionData on the associations of fatty acids with chronic kidney disease (CKD) are sparse.Materials and methodsWe performed a cross-sectional study of 2792 men and women from the MESA cohort of African–American, Caucasian, Chinese and Hispanic adults without known cardiovascular disease. Plasma phospholipid fatty acid proportions were associated with estimated glomerular filtration rate (eGFR) and the albumin/creatinine ratio.ResultsCis-vaccenic acid (18:1n?7), adjusted for other fatty acids using multivariate logistic regression (CI: 1.0–1.4), and step-wise logistic regression (CI: 1.02–1.42), was positively associated with reduced eGFR. The Framingham Risk Score, when adjusting for fatty acid proportions and demographic factors, was positively associated with CKD as measured by the eGFR and the albumin/creatinine ratio.Discussion and conclusionsPlasma phospholipid proportions of the 18 carbon monounsaturated cis-vaccenic acid {18:1n?7}) and the Framingham Risk Score are associated with kidney function. The potential role of 18:1n?7 in the development of CKD warrants further investigation. 相似文献
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16.
Shoda-Kagaya E 《Bulletin of entomological research》2007,97(2):167-174
To study the dispersal process of the pine sawyer Monochamus alternatus (Hope) in frontier populations, a microsatellite marker-based genetic analysis was performed on expanding populations at the northern limit of its range in Japan. In Asian countries, M. alternatus is the main vector of pine wilt disease, the most serious forest disease in Japan. Sawyers were collected from nine sites near the frontier of the pine wilt disease damage area. A mountain range divides the population into western and eastern sides. Five microsatellite loci were examined and a total of 188 individuals was genotyped from each locus with the number of alleles ranged from two to nine. The mean observed heterozygosity for all loci varied from 0.282 to 0.480 in the nine sites, with an overall mean of 0.364. None of the populations have experienced a significant bottleneck. Significant differentiation was found across the mountain range, but the genetic composition was similar amongst populations of each side. It is believed that the mountain range acts as a geographical barrier to dispersal and that gene flow without a geographical barrier is high. On the west side of the mountain range, a pattern of isolation by distance was detected. This was likely to be caused by secondary contact of different colonizing routes on a small spatial scale. Based on these data, a process linking genetic structure at local (kilometres) and regional spatial scales (hundreds of kilometres) was proposed. 相似文献
17.
Baird Mark E.; Emsley Steve M.; Mcglade Jacqueline M. 《Journal of plankton research》2001,23(8):841-848
In the preceding paper in this issue, a phytoplankton growthmodel based on an analogy with chemical kinetics (the CR model)was re-derived, and a comparison made with the growth rate ofcultured phytoplankton assemblages extracted from temperatelakes. In this paper, further derivation of the CR model leadsto the same model of carbon isotope fractionation used by Rauet al. (Mar. Ecol. Prog. Ser., 133, 275285, 1996). Boththe CR and Rau et al. models are compatible with the observationthat isotope fractionation during phytoplankton growth, 相似文献
18.
From Asia to Europe across Siberia: phylogeography of the Siberian spined loach (Teleostei,Cobitidae) 下载免费PDF全文
We assessed the genetic variability of the Siberian spined loach Cobitis melanoleuca across its unusually broad distribution that encompasses areas greatly affected by Pleistocene glaciations. Due to extensive morphological variation among their populations, the taxonomic status of C. melanoleuca is complicated. It is unclear whether C. melanoleuca represents a single taxonomic unit or contains several species or subspecies. Our analyses showed low genetic variability in all populations without any phylogenetic structure. The absence of molecular distinctiveness indicates the conspecificity of all C. melanoleuca populations. Only a few common haplotypes shared by East Asian, Siberian and European populations were found at high frequency in the nuclear genes analysed. At the mitochondrial level, Siberian populations shared haplotypes with populations located at both extremes of the species’ range suggesting central populations as a source of current mitochondrial variability. Unimodal mismatch distributions and significant values from neutrality tests support a recent expansion of C. melanoleuca. Our time estimates suggest a postglacial colonisation of European waters around 1.0 MYA, indicating that C. melanoleuca may represent the last cobitid immigrant in Europe that used the northern route across Siberia to expand its range. 相似文献
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Yasrebi H 《Bioinformatics (Oxford, England)》2011,27(8):1168-1169
SurvJamda (Survival prediction by joint analysis of microarray data) is an R package that utilizes joint analysis of microarray gene expression data to predict patients' survival and risk assessment. Joint analysis can be performed by merging datasets or meta-analysis to increase the sample size and to improve survival prognosis. The prognosis performance derived from the combined datasets can be assessed to determine which feature selection approach, joint analysis method and bias estimation provide the most robust prognosis for a given set of datasets. AVAILABILITY: The survJamda package is available at the Comprehensive R Archive Network, http://cran.r-project.org. CONTACT: hyasrebi@yahoo.com. 相似文献