Arbuscular mycorrhizal fungi for the biocontrol of plant-parasitic nematodes: a review of the mechanisms involved

Arbuscular mycorrhizal fungi (AMF) are obligate root symbionts that can protect their host plant against biotic stress factors such as plant-parasitic nematode (PPN) infection. PPN consist of a wide range of species with different life styles that can cause major damage in many important crops worldwide. Various mechanisms have been proposed to play a role in the biocontrol effect of AMF against PPN. This review presents an overview of the different mechanisms that have been proposed, and discusses into more detail the plausibility of their involvement in the biocontrol against PPN specifically. The proposed mechanisms include enhanced plant tolerance, direct competition for nutrients and space, induced systemic resistance (ISR) and altered rhizosphere interactions. Recent studies have emphasized the importance of ISR in biocontrol and are increasingly placing rhizosphere effects on the foreground as well, both of which will be the focal point of this review. Though AMF are not yet widely used in conventional agriculture, recent data help to develop a better insight into the modes of action, which will eventually lead toward future field applications of AMF against PPN. The scientific community has entered an exciting era that provides the tools to actually unravel the underlying molecular mechanisms, making this a timely opportunity for a review of our current knowledge and the challenges ahead

Nomenclature usuelle de 550 fibres textiles : avec indication de leur provenance, leurs usages, etc.

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Lung penetration, bronchopulmonary pharmacokinetic/pharmacodynamic profile and safety of 3 g of ceftolozane/tazobactam administered to ventilated, critically ill patients with pneumonia

Objectives: Ceftolozane/tazobactam is approved for hospital-acquired/ventilator-associated bacterial pneumonia at double the dose (i.e. 2 g/1 g) recommended for other indications. We evaluated the bronchopulmonary pharmacokinetic/pharmacodynamic profile of this 3 g ceftolozane/tazobactam regimen in ventilated pneumonia patients. Methods: This was an open-label, multicentre, Phase 1 trial (clinicaltrials.gov: NCT02387372). Mechanically ventilated patients with proven/suspected pneumonia received four to six doses of 3 g of ceftolozane/tazobactam (adjusted for renal function) q8h. Serial plasma samples were collected after the first and last doses. One bronchoalveolar lavage sample per patient was collected at 1, 2, 4, 6 or 8 h after the last dose and epithelial lining fluid (ELF) drug concentrations were determined. Pharmacokinetic parameters were estimated by noncompartmental analysis and pharmacodynamic analyses were conducted to graphically evaluate achievement of target exposures (plasma and ELF ceftolozane concentrations >4 mg/L and tazobactam concentrations >1 mg/L; target in plasma: similar to 30% and similar to 20% of the dosing interval, respectively). Results: Twenty-six patients received four to six doses of study drug; 22 were included in the ELF analyses. Ceftolozane and tazobactam T-max (6 and 2 h, respectively) were delayed in ELF compared with plasma (1h). Lung penetration, expressed as the ratio of mean drug exposure (AUC) in ELF to plasma, was 50% (ceftolozane) and 62% (tazobactam). Mean ceftolozane and tazobactam ELF concentrations remained >4 mg/L and >1mg/L, respectively, for 100% of the dosing interval. Therewere no deaths or adverse event-related study discontinuations. Conclusions: In ventilated pneumonia patients, 3 g of ceftolozane/tazobactam q8h yielded ELF exposures considered adequate to cover ceftolozane/tazobactam-susceptible respiratory pathogens

A clinician’s guide to management of intra-abdominal hypertension and abdominal compartment syndrome in critically ill patients

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2020. Other selected articles can be found online at . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901

The geochronological framework of the Irumide Belt: A prolonged crustal history along the margin of the Bangweulu Craton.

Ion microprobe U-Th-Pb analyses of zircon from 40 granitoid rocks collected from the late Mesoproterozoic Irumide Belt in Central Southern Africa, along the southern margin of the Archean to Paleoproterozoic Bangweulu Block, provide a comprehensive set of age data for this complex orogen. The data indicate that the Irumide Belt is constructed on a basement of principally Paleoproterozoic (ca. 2.05–1.93 Ga) age with a subordinate Neoarchean (ca. 2.73 Ga) component, which is overlain by a platformal quartzite-pelite succession known as the Muva Supergroup. Previously published U-Pb detrital zircon data for the Paleoproterozoic Muva Supergroup, which show age populations that match all of the pre-1.9 Ga basement components identified within the Irumide Belt, suggest that the pre-Muva basement was assembled as a coherent block by ~1.8 Ga, which we refer to as the Bangweulu Craton. The southern margin of the Bangweulu Craton was then intruded by a previously unrecognized suite of biotite-bearing granitoid rocks between 1.66 and 1.55 Ga, not recorded elsewhere in the region, and was later the site of emplacement of voluminous granitoid magmatism during the Irumide Orogeny at between 1.05 and 1.00 Ga. Hf isotopic data from zircon in these suites indicate variable influence from cryptic Archean rocks in the lower crustal melting zone of the Bangweulu Block. U-Pb analyses of inherited zircon cores in magmatic zircon in these granitoid rocks, directly confirm the presence of this reworked cryptic Archean basement of the Bangweulu Craton.The age data confirm previously proposed tectonic models for the Mesoproterozoic evolution of central Africa, refuting the presence of a continent-spanning Grenvillian-aged Orogen, including the Kibaran Belt, Irumide Belt and Choma-Kalomo Block of central Africa and connecting with Mesoproterozoic terranes further south along the margins of the Kalahari Craton. The data clearly show that the Proterozoic tectonic evolution of the Bangweulu Craton, which became attached to the southern margin of the larger Congo Craton during the Mesoproterozoic, involved a series of distinct convergent orogenic episodes affecting and reworking its southern (passive) margin. The mismatch in timing of Mesoproterozoic orogenic activity along the Bangweulu Craton, compared to that on the margins of the Kalahari, is compatible with the notion that these continental fragments were not juxtaposed along these Mesoproterozoic belts and in their present-day relative positions at the time. Whether either of these central and southern African cratons did form part of Rodinia, however, remains a matter for debate

Proterozoic tectonostratigraphy and paleogeography of central Madagascar derived from detrital zircon U-Pb age populations

Detrital zircon U-Pb ages determined by SHRIMP distinguish two clastic sequences among Proterozoic metasedimentary rocks from central Madagascar. The Itremo Group is older: zircon data, stromatolite characteristics, and carbon isotope data all point to a depositional age around 1500-1700 Ma. The Molo Group is younger, deposited between ∼620 Ma (the age of the youngest zircon) and ∼560 Ma (the age of metamorphic overgrowths on detrital cores). Geochronologic provenance analysis of the Itremo Group points to sources in East Africa as well as local sources in central and southern Madagascar but provides no evidence for a detrital contribution from northern and eastern Madagascar nor from southern India. Detrital zircon and sedimentologic similarities between rocks of the Itremo Group and the Zambian Muva Supergroup suggest a lithostratigraphic correlation between the two. The Molo Group has a strong 1000-1100 Ma detrital signature that also indicates an east African provenance and suggests a Neoproterozoic geographic connection with Sri Lanka but shows no indication of input from the Dharwar craton and eastern Madagascar. Central Madagascar was probably juxtaposed with the Tanzanian craton in the Paleo- and Mesoproterozoic, whereas northern and eastern Madagascar were connected to India. Internal assembly of Madagascar postdates Neoproterozoic Molo Group sedimentation and is likely to have occurred at about 560 Ma. © 2004 by The University of Chicago. All rights reserved.Rónadh Cox, Drew S. Coleman, Carla B. Chokel, Stephen B. DeOreo, Joseph L. Wooden, Alan S. Collins, Bert De Waele, and Alfred Kröne

The approach to vortex reconnection

We present numerical solutions of the Gross--Pitaevskii equation corresponding to reconnecting vortex lines. We determine the separation of vortices as a function of time during the approach to reconnection, and study the formation of pyramidal vortex structures. Results are compared with analytical work and numerical studies based on the vortex filament method.Comment: 11 pages, 9 figure

Hydrogeology and geochemistry of the sulfur karst springs at Santa Cesarea Terme (Apulia, southern Italy)

This work describes the geochemical and hydrogeological characteristics of Santa Cesarea Terme, an active sulfuric acid speleogenetic system located along the Adriatic coastline (Apulia, southern Italy). It represents a very peculiar site, where rising thermal and acidic waters mix with seawater creating undersaturated solutions with respect to CaCO3, able to dissolve and corrode limestone and create caves. The Santa Cesarea Terme system is composed of four caves: Fetida, Sulfurea, Gattulla, and Solfatara. Hypogene morphologies and abundant deposits of native sulfur (especially in Gattulla Cave) and sulfate minerals are present in these caves. Fetida and Gattulla caves were investigated primarily because they are easily accessible throughout the whole year through artificial entrances, the other caves being reachable only from the sea. Geochemical analysis of water, monitoring of cave atmosphere, and measurement of the stable isotopes of S, O, and H helped to identify the main processes occurring in this complex cave system. In particular, changes in Ba2+ and Sr2+ concentration allowed for the identification of two main domains of influence, characterized by marine and rising acidic waters