The exotic invasive plant Vincetoxicum rossicum is a strong competitor even outside its current realized climatic temperature range

Dog-strangling vine (Vincetoxicum rossicum) is an exotic plant originating from Central and Eastern Europe that is becoming increasingly invasive in southern Ontario, Canada. Once established, it successfully displaces local native plant species but mechanisms behind this plant’s high competitive ability are not fully understood. It is unknown whether cooler temperatures will limit the range expansion of V. rossicum, which has demonstrated high tolerance for other environmental variables such as light and soil moisture. Furthermore, if V. rossicum can establish outside its current climatic limit it is unknown whether competition with native species can significantly contribute to reduce fitness and slow down invasion. We conducted an experiment to test the potential of V. rossicum to spread into northern areas of Ontario using a set of growth chambers to simulate southern and northern Ontario climatic temperature regimes. We also tested plant-plant competition by growing V. rossicum in pots with a highly abundant native species, Solidago canadensis, and comparing growth responses to plants grown alone. We found that the fitness of V. rossicum was not affected by the cooler climate despite a delay in reproductive phenology. Growing V. rossicum with S. canadensis caused a significant reduction in seedpod biomass of V. rossicum. However, we did not detect a temperature x competition interaction in spite of evidence for adaptation of S. canadensis to cooler temperature conditions. We conclude that the spread of V. rossicum north within the tested range is unlikely to be limited by climatic temperature but competition with an abundant native species may contribute to slow it down

Application of plant–soil feedbacks in the selection of crop rotation sequences

Plant–soil feedback (PSF) can be a major driver of plant performance in com- munities, and this concept can be used in selecting crop rotation sequences to maximize agricultural yields. Potential benefits of using PSF in this context include nutrient use optimization, pathogen reduction, and enhancement of mutualisms between crops and microbes. Yet the contributions of these com- bined mechanisms are poorly understood. Here we investigated the relative contributions of these mechanisms using five major crops commonly culti- vated in rotation (alfalfa, canola, maize, soybean, and wheat) under controlled conditions. We trained soil by growing each of the five crops in a “training phase,” and then reciprocally planted the five crops in the trained soils in a “feedback phase.” To tease out soil biota from nutrient effects, we established three treatments: “control” (trained unsterilized soil used in the feedback phases), “biota” (sterilized soil in the feedback phase inoculated with soil biota from the control treatment after the training phase), and “nutrient” (sterilized soils in both phases). Plant–soil feedback for each crop was calculated by com- paring the total biomass of each crop grown in soils trained by each of the four other crops (i.e., in rotation) against total biomass in self-trained soil (i.e., monocropping). We found that PSF values varied among crop combina- tions in all the treatments, but such variation was the greatest in the nutrient treatment. Overall, soil biota feedback tended to be lower, whereas nutrient feedback tended to be greater compared to the unsterilized control soil, suggesting that effects of antagonistic biota outweighed those of beneficial microbes in the biota treatment, and that plants optimized nutrient uptake when the soil microbiome was absent in the nutrient treatment. Furthermore, soils in the nutrient treatment trained by the legume crops (alfalfa and soy- bean) tended to provide the greatest positive feedback, emphasizing the impor- tant legacy of N2 fixers in crop rotation. Taken together, our data demonstrate how nutrients and soil biota can be integral to PSFs among crops, and that assessing PSFs under controlled conditions can serve as a basis to determine the most productive crop rotation sequences prior to field testing.info:eu-repo/semantics/publishedVersio

Does a Carbonatite Deposit Influence Its Surrounding Ecosystem?

Carbonatites are unusual alkaline rocks with diverse compositions. Although previous work has characterized the effects these rocks have on soils and plants, little is known about their impacts on local ecosystems. Using a deposit within the Great Lakes–St. Lawrence forest in northern Ontario, Canada, we investigated the effect of a carbonatite on soil chemistry and on the structure of plant and soil microbial communities. This was done using a vegetation survey conducted above and around the deposit, with corresponding soil samples collected for determining soil nutrient composition and for assessing microbial community structure using 16S/ITS Illumina Mi-Seq sequencing. In some soils above the deposit a soil chemical signature of the carbonatite was found, with the most important effect being an increase in soil pH compared with the non-deposit soils. Both plants and microorganisms responded to the altered soil chemistry: the plant communities present in carbonatite-impacted soils were dominated by ruderal species, and although differences in microbial communities across the surveyed areas were not obvious, the abundances of specific bacteria and fungi were reduced in response to the carbonatite. Overall, the deposit seems to have created microenvironments of relatively basic soil in an otherwise acidic forest soil. This study demonstrates for the first time how carbonatites can alter ecosystems in situ

High resolution stratigraphy and miocene facies correlation in Lisbon and Setúbal Peninsula (Lower Tagus basin, Portugal)

Correlation between facies associations (marine, estuarine and distal fluviatile environments) and disconformities, observed between Foz da Fonte (SW of Setúbal Peninsula) and Santa Iria da Azóia (NE of Lisbon) are presented. The precise definition of the marine-continental facies relationships improved very much the chronology of the depositional sequence boundaries. Tectonic and eustatic controls are discussed on the basis of subsidence rates variation

A pilot study on fear and risk of fall: The impact of an8-month multicomponent exercise program in community-dwelling aged adults

The objective of this study was to investigate the impact of an 8-month multicomponent exercise program in community-dwelling older adults. A comprehensive approach was employed to assess the feasibility and effectiveness of a thrice-weekly exercise intervention. Aged over 60 years, the capacity to stand and walk with or without assistive equipment, being physically inactive, medical clearance, and living in the community were all eligibility criteria. The Timed-up and Go test and Berg Balance Scale were used to examine risk of falling. The Fall-Efficacy Scale International was used to examine the fear of falling. The community-based exercise program involved thirty-five participants, the average age was 67.54 years (SD = 3.81) and 71% were female. At-tendance rates ranged from 76% to 100% on average. There was a significant trend toward a clinically important improvement in the timed-up and go test (t = 4.66; p < .001; d = 0.20), berg balance scale (t = -11.20; p < .001; d = 1.47) and fall-efficacy scale international (t = 5.81; p < .001; d = 0.88). This study has provided preliminary evidence that an 8-month community-based low-cost exercise program may be effective in improving agility, balance, and decreasing fear of falling in older people.info:eu-repo/semantics/publishedVersio

Prevailing Negative Soil Biota Effect and No Evidence for Local Adaptation in a Widespread Eurasian Grass

Soil biota effects are increasingly accepted as an important driver of the abundance and distribution of plants. While biogeographical studies on alien invasive plant species have indicated coevolution with soil biota in their native distribution range, it is unknown whether adaptation to soil biota varies among populations within the native distribution range. The question of local adaptation between plants and their soil biota has important implications for conservation of biodiversity and may justify the use of seed material from local provenances in restoration campaigns.We studied soil biota effects in ten populations of the steppe grass Stipa capillata from two distinct regions, Europe and Asia. We tested for local adaptation at two different scales, both within (ca. 10-80 km) and between (ca. 3300 km) regions, using a reciprocal inoculation experiment in the greenhouse for nine months. Generally, negative soil biota effects were consistent. However, we did not find evidence for local adaptation: both within and between regions, growth of plants in their 'home soil' was not significantly larger relative to that in soil from other, more distant, populations.Our study suggests that negative soil biota effects can prevail in different parts of a plant species' range. Absence of local adaptation points to the possibility of similar rhizosphere biota composition across populations and regions, sufficient gene flow to prevent coevolution, selection in favor of plasticity, or functional redundancy among different soil biota. From the point of view of plant--soil biota interactions, our findings indicate that the current practice of using seeds exclusively from local provenances in ecosystem restoration campaigns may not be justified

Análise da variabilidade do IRI obtido por vários perfilómetros

A irregularidade longitudinal, caracterizada habitualmente pelo Índice Internacional de Irregularidade (IRI – International Roughness Index), é um dos parâmetros de estado dos pavimentos rodoviários cuja variabilidade pode ter consequências relevantes nas estratégias de reabilitação e, consequentemente, nos custos e na sua vida de serviço. Por esta razão, este artigo tem por principal objectivo proporcionar às entidades referidas informação útil no que respeita à variabilidade do IRI, calculado a partir de dados obtidos por vários perfilómetros. Assim, foram seleccionados cinco veículos do tipo”multifunções”, que pertencem quer a empresas de consultadoria quer a instituições de investigação, e três trechos de estrada com camadas de desgaste em betão betuminoso drenante, betão betuminosos rugoso e betão betuminoso “convencional”. Cada veículo percorreu cinco vezes cada trecho nos dois sentidos de tráfego. O espaçamento adoptado para o cálculo do IRI foi de 100 m. A média e o desvio padrão foram os parâmetros usados para estudar a variabilidade dos resultados. De uma forma geral verificou-se que o valor do desvio padrão do IRI é 20 a 30% do valor da média

Estuarine consumers utilize marine, estuarine and terrestrial organic matter and provide connectivity among these food webs

The flux of organic matter (OM) across ecosystem boundaries can influence estuarine food web dynamics and productivity. However, this process is seldom investigated taking into account all the adjacent ecosystems (e.g. ocean, river, land) and different hydrological settings (i.e. river discharge). Therefore, we aimed to quantify the contribution of autochthonous and allochthonous OM to the lower food web along the estuarine salinity gradient, under different river discharge conditions. The carbon (C) and nitrogen (N) stable isotope ratios of pelagic (zooplankton) and benthic (Corbicula fluminea) primary consumers indicated that they rely on a mixture of autochthonous and allochthonous OM, including terrestrial-derived OM. Unexpectedly, the highest contribution of terrestrial-derived OM to the estuarine food web was observed during a low river discharge period (up to 70%), that succeeded a large winter flood, showing that extreme weather events may produce prolonged effects on estuarine food webs. The contribution of marine-derived OM was higher during low river discharge periods (up to 88%) and was restricted to the seaward end of the estuary. Concomitantly, the contribution of phytoplankton to primary consumers was the highest observed (up to 91%). Further, both pelagic and benthic consumers also relied on benthic C (i.e. sediment OM and microphytobenthos). This study demonstrates that primary consumers enhance connectivity between estuarine ecosystems by utilizing subsidies of terrestrial and marine origin, and also between estuarine habitats through reliance on pelagic and benthic OM

Remifentanil bolus dose is a safe procedure to control intense noxious stimuli in hypertensive neurosurgical patients

Patients with hypertension may be more prone to develop hypotension as a consequence of opioid administration under general anesthesia. The hemodynamic and bispectral index responses to a remifentanil bolus in neurosurgical hypertensive patients under target-controlled infusion with propofol and remifentanil are addressed. Ten healthy patients and 10 patients with diagnosed hypertension under pharmacological treatment were studied. A 2 µg/kg remifentanil bolus was administered to all patients before skin incision under target-controlled infusion with propofol and remifentanil. Mean arterial pressure, heart rate, and the area under the curve for the bispectral index of the electroencephalogram were analyzed within the groups and compared between them every 30 seconds for two minutes following the bolus. Two minutes after the remifentanil bolus, remifentanil predicted effect-site concentrations reached maximum values of 8.46±0.91 ng/ml and 9.74±1.29 ng/ml in the healthy and hypertensive patients, respectively. Both groups showed a significant decrease in mean arterial pressure, heart rate, and in the area under the curve for the bispectral index. Mean arterial pressure decreased by 17.3±10% and 24±9%, heart rate by 11.1±8% and 12±8%, and the bispectral index by 13±9.2% and 8.6±8.4% in the healthy and hypertensive patients, respectively, 120 seconds after the remifentanil bolus. In a clinical situation in which high remifentanil doses may be required, hypertensive patients are expected to have hemodynamic and bispectral index responses similar to those observed in healthy patients.info:eu-repo/semantics/publishedVersio

Indigenous Arbuscular Mycorrhizal Fungal Assemblages Protect Grassland Host Plants from Pathogens

Plant roots can establish associations with neutral, beneficial and pathogenic groups of soil organisms. Although it has been recognized from the study of individual isolates that these associations are individually important for plant growth, little is known about interactions of whole assemblages of beneficial and pathogenic microorganisms associating with plants