169 resultados para invasive pests

em Université de Lausanne, Switzerland


Relevância:

60.00% 60.00%

Publicador:

Resumo:

Species delimitation has been invigorated as a discipline in systematics by an influx of new character sets, analytical methods, and conceptual advances. We use genetic data from 68 markers, combined with distributional, bioclimatic, and coloration information, to hypothesize boundaries of evolutionarily independent lineages (species) within the widespread and highly variable nominal fire ant species Solenopsis saevissima, a member of a species group containing invasive pests as well as species that are models for ecological and evolutionary research. Our integrated approach uses diverse methods of analysis to sequentially test whether populations meet specific operational criteria (contingent properties) for candidacy as morphologically cryptic species, including genetic clustering, monophyly, reproductive isolation, and occupation of distinctive niche space. We hypothesize that nominal S. saevissima comprises at least 4-6 previously unrecognized species, including several pairs whose parapatric distributions implicate the development of intrinsic premating or postmating barriers to gene flow. Our genetic data further suggest that regional genetic differentiation in S. saevissima has been influenced by hybridization with other nominal species occurring in sympatry or parapatry, including the quite distantly related Solenopsis geminata. The results of this study illustrate the importance of employing different classes of genetic data (coding and noncoding regions and nuclear and mitochondrial DNA [mtDNA] markers), different methods of genetic data analysis (tree-based and non-tree based methods), and different sources of data (genetic, morphological, and ecological data) to explicitly test various operational criteria for species boundaries in clades of recently diverged lineages, while warning against over reliance on any single data type (e.g., mtDNA sequence variation) when drawing inferences.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Climate change affects the rate of insect invasions as well as the abundance, distribution and impacts of such invasions on a global scale. Among the principal analytical approaches to predicting and understanding future impacts of biological invasions are Species Distribution Models (SDMs), typically in the form of correlative Ecological Niche Models (ENMs). An underlying assumption of ENMs is that species-environment relationships remain preserved during extrapolations in space and time, although this is widely criticised. The semi-mechanistic modelling platform, CLIMEX, employs a top-down approach using species ecophysiological traits and is able to avoid some of the issues of extrapolation, making it highly applicable to investigating biological invasions in the context of climate change. The tephritid fruit flies (Diptera: Tephritidae) comprise some of the most successful invasive species and serious economic pests around the world. Here we project 12 tephritid species CLIMEX models into future climate scenarios to examine overall patterns of climate suitability and forecast potential distributional changes for this group. We further compare the aggregate response of the group against species-specific responses. We then consider additional drivers of biological invasions to examine how invasion potential is influenced by climate, fruit production and trade indices. Considering the group of tephritid species examined here, climate change is predicted to decrease global climate suitability and to shift the cumulative distribution poleward. However, when examining species-level patterns, the predominant directionality of range shifts for 11 of the 12 species is eastward. Most notably, management will need to consider regional changes in fruit fly species invasion potential where high fruit production, trade indices and predicted distributions of these flies overlap.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Operative treatment of coronoid fracture often requires a large dissection of soft tissue, resulting in elbow stiffness and functional limitation. The authors present a minimal invasive, safe technique, useful in the case of isolated coronoid fracture associated with elbow dislocation. This technique does not require soft tissue dissection and allows an early unlimited resumption of sports activities.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

INTRODUCTION: Timely diagnosis of invasive candidiasis (IC) remains difficult as the clinical presentation is not specific and blood cultures lack sensitivity and need a long incubation time. Thus, non-culture-based methods for diagnosing IC have been developed. Mannan antigen (Mn) and anti-mannan antibodies (A-Mn) are present in patients with IC. On behalf of the Third European Conference on Infections in Leukemia, the performance of these tests was analysed and reviewed. METHODS: The literature was searched for studies using the commercially available sandwich enzyme-linked immunosorbent assays (Platelia™, Bio-Rad Laboratories, Marnes-la-Coquette, France) for detecting Mn and A-Mn in serum. The target condition of this review was IC defined according to 2008 European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria. Sensitivity, specificity and diagnostic odds ratios (DOR) were calculated for Mn, A-Mn and combined Mn/A-Mn testing. RESULTS: Overall, 14 studies that comprised 453 patients and 767 controls were reviewed. The patient populations included in the studies were mainly haematological and cancer cases in seven studies and mainly intensive care unit and surgery cases in the other seven studies. All studies but one were retrospective in design. Mn sensitivity was 58% (95% confidence interval [CI], 53-62); specificity, 93% (95% CI, 91-94) and DOR, 18 (95% CI 12-28). A-Mn sensitivity was 59% (95% CI, 54-65); specificity, 83% (95% CI, 79-97) and DOR, 12 (95% CI 7-21). Combined Mn/A-Mn sensitivity was 83% (95% CI, 79-87); specificity, 86% (95% CI, 82-90) and DOR, 58 (95% CI 27-122). Significant heterogeneity of the studies was detected. The sensitivity of both Mn and A-Mn varied for different Candida species, and it was the highest for C. albicans, followed by C. glabrata and C. tropicalis. In 73% of 45 patients with candidemia, at least one of the serological tests was positive before the culture results, with mean time advantage being 6 days for Mn and 7 days for A-Mn. In 21 patients with hepatosplenic IC, 18 (86%) had Mn or A-Mn positive test results at a median of 16 days before radiological detection of liver or spleen lesions. CONCLUSIONS: Mn and A-Mn are useful for diagnosis of IC. The performance of combined Mn/A-Mn testing is superior to either Mn or A-Mn testing.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: Recommended oral voriconazole (VRC) doses are lower than intravenous doses. Because plasma concentrations impact efficacy and safety of therapy, optimizing individual drug exposure may improve these outcomes. METHODS: A population pharmacokinetic analysis (NONMEM) was performed on 505 plasma concentration measurements involving 55 patients with invasive mycoses who received recommended VRC doses. RESULTS: A 1-compartment model with first-order absorption and elimination best fitted the data. VRC clearance was 5.2 L/h, the volume of distribution was 92 L, the absorption rate constant was 1.1 hour(-1), and oral bioavailability was 0.63. Severe cholestasis decreased VRC elimination by 52%. A large interpatient variability was observed on clearance (coefficient of variation [CV], 40%) and bioavailability (CV 84%), and an interoccasion variability was observed on bioavailability (CV, 93%). Lack of response to therapy occurred in 12 of 55 patients (22%), and grade 3 neurotoxicity occurred in 5 of 55 patients (9%). A logistic multivariate regression analysis revealed an independent association between VRC trough concentrations and probability of response or neurotoxicity by identifying a therapeutic range of 1.5 mg/L (>85% probability of response) to 4.5 mg/L (<15% probability of neurotoxicity). Population-based simulations with the recommended 200 mg oral or 300 mg intravenous twice-daily regimens predicted probabilities of 49% and 87%, respectively, for achievement of 1.5 mg/L and of 8% and 37%, respectively, for achievement of 4.5 mg/L. With 300-400 mg twice-daily oral doses and 200-300 mg twice-daily intravenous doses, the predicted probabilities of achieving the lower target concentration were 68%-78% for the oral regimen and 70%-87% for the intravenous regimen, and the predicted probabilities of achieving the upper target concentration were 19%-29% for the oral regimen and 18%-37% for the intravenous regimen. CONCLUSIONS: Higher oral than intravenous VRC doses, followed by individualized adjustments based on measured plasma concentrations, improve achievement of the therapeutic target that maximizes the probability of therapeutic response and minimizes the probability of neurotoxicity. These findings challenge dose recommendations for VRC.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: Invasive fungal infections (IFIs) are life-threatening complications in patients with hemato-oncological malignancies, and early diagnosis is crucial for outcome. The compound 1,3-β-D-glucan (BG), a cell wall component of most fungal species, can be detected in blood during IFI. Four commercial BG antigenemia assays are available (Fungitell, Fungitec-G, Wako, and Maruha). This meta-analysis from the Third European Conference on Infections in Leukemia (ECIL-3) assessed the performance of BG assays for the diagnosis of IFI in hemato-oncological patients. METHODS: Studies reporting the performance of BG antigenemia assays for the diagnosis of IFI (European Organization for Research and Treatment of Cancer and Mycoses Study Group criteria) in hemato-oncological patients were identified. The analysis was focused on high-quality cohort studies with exclusion of case-control studies. Meta-analysis was performed by conventional meta-analytical pooling and bivariate analysis. RESULTS: Six cohort studies were included (1771 adult patients with 414 IFIs of which 215 were proven or probable). Similar performance was observed among the different BG assays. For the cutoff recommended by the manufacturer, the diagnostic performance of the BG assay in proven or probable IFI was better with 2 consecutive positive test results (diagnostic odds ratio for 2 consecutive vs one single positive results, 111.8 [95% confidence interval {CI}, 38.6-324.1] vs 16.3 [95% CI, 6.5-40.8], respectively; heterogeneity index for 2 consecutive vs one single positive results, 0% vs 72.6%, respectively). For 2 consecutive tests, sensitivity and specificity were 49.6% (95% CI, 34.0%-65.3%) and 98.9% (95% CI, 97.4%-99.5%), respectively. Estimated positive and negative predictive values for an IFI prevalence of 10% were 83.5% and 94.6%, respectively. CONCLUSIONS: Different BG assays have similar accuracy for the diagnosis of IFI in hemato-oncological patients. Two consecutive positive antigenemia assays have very high specificity, positive predictive value, and negative predictive value. Because sensitivity is low, the test needs to be combined with clinical, radiological, and microbiological findings.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Non-indigenous species can have strong impacts on biodiversity by affecting trophic relationships in their new environments. The piscivorous dice snake (Natrix tessellata) has been introduced to Geneva Lake, western Switzerland, where the endangered viperine snake (Natrix maura) is native. Local, dramatic declines in the viperine snake population might be associated with the appearance of the dice snake through dietary overlap between these 2 species, which mainly feed on bullhead (Cottus gobio). In response to this decline, a control program for dice snake was implemented in 2007 to reduce numbers of this introduced snake. In 2010, a new species of fish, the freshwater blenny (Salaria fluviatilis), which shares the same habitat as the bullhead, was introduced into Lake Geneva and has since reached high densities. We determined the impact of freshwater blenny on diet composition and body condition of dice snakes. In addition, we tested for effects of the control program on the body condition of dice snakes and viperine snakes. We collected 294 dice snakes between 2007 and 2013. Based on morphology and a genetic marker (cytochrome b gene), we determined the ®sh species contained in these snakes' stomachs. We found a drastic switch in dice snake diet following the arrival of freshwater blenny, as consumption of bullhead declined by 68% and was replaced by the blenny. In addition, the body condition of dice snakes increased significantly after the arrival of freshwater blenny. The body condition of both snake species was positively correlated with the number of dice snakes removed from the study area. This finding has important implications concerning the conservation of the endangered viperine snake, and suggests that the control program of dice snakes should be continued.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Biological invasions and land-use changes are two major causes of the global modifications of biodiversity. Habitat suitability models are the tools of choice to predict potential distributions of invasive species. Although land-use is a key driver of alien species invasions, it is often assumed that land-use is constant in time. Here we combine historical and present day information, to evaluate whether land-use changes could explain the dynamic of invasion of the American bullfrog Rana catesbeiana (=Lithobathes catesbeianus) in Northern Italy, from the 1950s to present-day. We used maxent to build habitat suitability models, on the basis of past (1960s, 1980s) and present-day data on land-uses and species distribution. For example, we used models built using the 1960s data to predict distribution in the 1980s, and so on. Furthermore, we used land-use scenarios to project suitability in the future. Habitat suitability models predicted well the spread of bullfrogs in the subsequent temporal step. Models considering land-use changes predicted invasion dynamics better than models assuming constant land-use over the last 50 years. Scenarios of future land-use suggest that suitability will remain similar in the next years. Habitat suitability models can help to understand and predict the dynamics of invasions; however, land-use is not constant in time: land-use modifications can strongly affect invasions; furthermore, both land management and the suitability of a given land-use class may vary in time. An integration of land-use changes in studies of biological invasions can help to improve management strategies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Invasive candidiasis (IC) is a relatively common syndrome in neonates and children and is associated with significant morbidity and mortality. These guidelines provide recommendations for the prevention and treatment of IC in neonates and children. Appropriate agents for the prevention of IC in neonates at high risk include fluconazole (A-I), nystatin (B-II) or lactoferrin ± Lactobacillus (B-II). The treatment of IC in neonates is complicated by the high likelihood of disseminated disease, including the possibility of infection within the central nervous system. Amphotericin B deoxycholate (B-II), liposomal amphotericin B (B-II), amphotericin B lipid complex (ABLC) (C-II), fluconazole (B-II), micafungin (B-II) and caspofungin (C-II) can all be potentially used. Recommendations for the prevention of IC in children are largely extrapolated from studies performed in adults with concomitant pharmacokinetic data and models in children. For allogeneic HSCT recipients, fluconazole (A-I), voriconazole (A-I), micafungin (A-I), itraconazole (B-II) and posaconazole (B-II) can all be used. Similar recommendations are made for the prevention of IC in children in other risk groups. With several exceptions, recommendations for the treatment of IC in children are extrapolated from adult studies, with concomitant pharmacokinetic studies. Amphotericin B deoxycholate (C-I), liposomal amphotericin B (A-I), ABLC (B-II), micafungin (A-I), caspofungin (A-I), anidulafungin (B-II), fluconazole (B-I) and voriconazole (B-I) can all be used.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The application of microbial biocontrol agents for the control of fungal plant diseases and plant insect pests is a promising approach in the development of environmentally benign pest management strategies. The ideal biocontrol organism would be a bacterium or a fungus with activity against both, insect pests and fungal pathogens. Here we demonstrate the oral insecticidal activity of the root colonizing Pseudomonas fluorescens CHA0, which is so far known for its capacity to efficiently suppress fungal plant pathogens. Feeding assays with CHA0-sprayed leaves showed that this strain displays oral insecticidal activity and is able to efficiently kill larvae of three important insect pests. We further show data indicating that the Fit insect toxin produced by CHA0 and also metabolites controlled by the global regulator GacA contribute to oral insect toxicity.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An online algorithm for determining respiratory mechanics in patients using non-invasive ventilation (NIV) in pressure support mode was developed and embedded in a ventilator system. Based on multiple linear regression (MLR) of respiratory data, the algorithm was tested on a patient bench model under conditions with and without leak and simulating a variety of mechanics. Bland-Altman analysis indicates reliable measures of compliance across the clinical range of interest (± 11-18% limits of agreement). Resistance measures showed large quantitative errors (30-50%), however, it was still possible to qualitatively distinguish between normal and obstructive resistances. This outcome provides clinically significant information for ventilator titration and patient management.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Reticulitermes santonensis is a subterranean termite that invades urban areas in France and elsewhere where it causes damage to human-built structures. We investigated the breeding system, colony and population genetic structure, and mode of dispersal of two French populations of R. santonensis. Termite workers were sampled from 43 and 31 collection points, respectively, from a natural population in west-central France (in and around the island of Oleron) and an urban population (Paris). Ten to 20 workers per collection point were genotyped at nine variable microsatellite loci to determine colony identity and to infer colony breeding structure. There was a total of 26 colonies, some of which were spatially expansive, extending up to 320 linear metres. Altogether, the analysis of genotype distribution, F-statistics and relatedness coefficients suggested that all colonies were extended families headed by numerous neotenics (nonwinged precocious reproductives) probably descended from pairs of primary (winged) reproductives. Isolation by distance among collection points within two large colonies from both populations suggested spatially separated reproductive centres with restricted movement of workers and neotenics. There was a moderate level of genetic differentiation (F(ST) = 0.10) between the Oleron and Paris populations, and the number of alleles was significantly higher in Oleron than in Paris, as expected if the Paris population went through bottlenecks when it was introduced from western France. We hypothesize that the diverse and flexible breeding systems found in subterranean termites pre-adapt them to invade new or marginal habitats. Considering that R. santonensis may be an introduced population of the North American species R. flavipes, a breeding system consisting primarily of extended family colonies containing many neotenic reproductives may facilitate human-mediated spread and establishment of R. santonensis in urban areas with harsh climates.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Despite advertising for NOTES in 2009, single trocart laparoscopic surgery is about to become a new standard in selected indications. As other important topics, the limits of oncological surgery are extended due to a systematic multidisciplinary approach. To discuss every publication would be difficult and our review will focus on a selected number of papers of importance for daily practice. As examples, the management of acute calculous cholecystitis, gastro-esophageal reflux, inguinal and incisional hernia repair as well as colorectal surgery are presented.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

BACKGROUND: The value of adenovirus plasma DNA detection as an indicator for adenovirus disease is unknown in the context of T cell-replete hematopoietic cell transplantation, of which adenovirus disease is an uncommon but serious complication. METHODS: Three groups of 62 T cell-replete hematopoietic cell transplant recipients were selected and tested for adenovirus in plasma by polymerase chain reaction. RESULTS: Adenovirus was detected in 21 (87.5%) of 24 patients with proven adenovirus disease (group 1), in 4 (21%) of 19 patients who shed adenovirus (group 2), and in 1 (10.5%) of 19 uninfected control patients. The maximum viral load was significantly higher in group 1 (median maximum viral load, 6.3x10(6) copies/mL; range, 0 to 1.0x10(9) copies/mL) than in group 2 (median maximum viral load, 0 copies/mL; range, 0 to 1.7x10(8) copies/mL; P<.001) and in group 3 (median maximum viral load, 0 copies/mL; range 0-40 copies/mL; P<.001). All patients in group 2 who developed adenoviremia had symptoms compatible with adenovirus disease (i.e., possible disease). A minimal plasma viral load of 10(3) copies/mL was detected in all patients with proven or possible disease. Adenoviremia was detectable at a median of 19.5 days (range, 8-48 days) and 24 days (range, 9-41 days) before death for patients with proven and possible adenovirus disease, respectively. CONCLUSION: Sustained or high-level adenoviremia appears to be a specific and sensitive indicator of adenovirus disease after T cell-replete hematopoietic cell transplantation. In the context of low prevalence of adenovirus disease, the use of polymerase chain reaction of plasma specimens to detect virus might be a valuable tool to identify and treat patients at risk for viral invasive disease.