369 research outputs found

    Occurrence and distribution of soil Fusarium species under wheat crop in zero tillage

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    The presence of Fusarium species in cultivated soils is commonly associated with plant debris and plant roots. Fusarium species are also soil saprophytes. The aim of this study was to examine the occurrence and distribution of soil Fusarium spp. at different soil depths in a zero tillage system after the wheat was harvested. Soil samples were obtained at three depths (0-5 cm, 5-10 cm and 10-20 cm) from five crop rotations: I, conservationist agriculture (wheatsorghum- soybean); II, mixed agriculture/livestock with pastures, without using winter or summer forages (wheatsorghum- soybean-canola-pastures); III, winter agriculture in depth limited soils (wheat-canola-barley-late soybean); IV, mixed with annual forage (wheat-oat/Vicia-sunflower); V, intensive agriculture (wheat-barley-canola, with alternation of soybean or late soybean). One hundred twenty two isolates of Fusarium were obtained and identified as F. equiseti, F. merismoides, F. oxysporum, F. scirpi and F. solani. The most prevalent species was F. oxysporum, which was observed in all sequences and depths. The Tukey's test showed that the relative frequency of F. oxysporum under intensive agricultural management was higher than in mixed traditional ones. The first 5 cm of soil showed statistically significant differences (p = 0.05) with respect to 5-10 cm and 10-20 cm depths. The ANOVA test for the relative frequency of the other species as F. equiseti, F. merismoides, F. scirpi and F. solani, did not show statistically significant differences (p ≤ 0.05). We did not find significant differences (p ≤ 0.05) in the effect of crop rotations and depth on Shannon, Simpson indexes and species richness. Therefore we conclude that the different sequences and the sampling depth did not affect the alpha diversity of Fusarium community in this system.Instituto de Botánica "Dr. Carlos Spegazzini

    Functional diversity of sharks and rays is highly vulnerable and supported by unique species and locations worldwide

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    Elasmobranchs (sharks, rays and skates) are among the most threatened marine vertebrates, yet their global functional diversity remains largely unknown. Here, we use a trait dataset of >1000 species to assess elasmobranch functional diversity and compare it against other previously studied biodiversity facets (taxonomic and phylogenetic), to identify species- and spatial- conservation priorities. We show that threatened species encompass the full extent of functional space and disproportionately include functionally distinct species. Applying the conservation metric FUSE (Functionally Unique, Specialised, and Endangered) reveals that most top-ranking species differ from the top Evolutionarily Distinct and Globally Endangered (EDGE) list. Spatial analyses further show that elasmobranch functional richness is concentrated along continental shelves and around oceanic islands, with 18 distinguishable hotspots. These hotspots only marginally overlap with those of other biodiversity facets, reflecting a distinct spatial fingerprint of functional diversity. Elasmobranch biodiversity facets converge with fishing pressure along the coast of China, which emerges as a critical frontier in conservation. Meanwhile, several components of elasmobranch functional diversity fall in high seas and/or outside the global network of marine protected areas. Overall, our results highlight acute vulnerability of the world’s elasmobranchs’ functional diversity and reveal global priorities for elasmobranch functional biodiversity previously overlooked

    Occurrence and distribution of soil Fusarium species under wheat crop in zero tillage

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    The presence of Fusarium species in cultivated soils is commonly associated with plant debris and plant roots. Fusarium species are also soil saprophytes. The aim of this study was to examine the occurrence and distribution of soil Fusarium spp. at different soil depths in a zero tillage system after the wheat was harvested. Soil samples were obtained at three depths (0-5 cm, 5-10 cm and 10-20 cm) from five crop rotations: I, conservationist agriculture (wheatsorghum- soybean); II, mixed agriculture/livestock with pastures, without using winter or summer forages (wheatsorghum- soybean-canola-pastures); III, winter agriculture in depth limited soils (wheat-canola-barley-late soybean); IV, mixed with annual forage (wheat-oat/Vicia-sunflower); V, intensive agriculture (wheat-barley-canola, with alternation of soybean or late soybean). One hundred twenty two isolates of Fusarium were obtained and identified as F. equiseti, F. merismoides, F. oxysporum, F. scirpi and F. solani. The most prevalent species was F. oxysporum, which was observed in all sequences and depths. The Tukey's test showed that the relative frequency of F. oxysporum under intensive agricultural management was higher than in mixed traditional ones. The first 5 cm of soil showed statistically significant differences (p = 0.05) with respect to 5-10 cm and 10-20 cm depths. The ANOVA test for the relative frequency of the other species as F. equiseti, F. merismoides, F. scirpi and F. solani, did not show statistically significant differences (p ≤ 0.05). We did not find significant differences (p ≤ 0.05) in the effect of crop rotations and depth on Shannon, Simpson indexes and species richness. Therefore we conclude that the different sequences and the sampling depth did not affect the alpha diversity of Fusarium community in this system.Instituto de Botánica "Dr. Carlos Spegazzini

    Fungal diversity in soils with different uses in the pampean region of Argentina

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    Los hongos son relevantes en la descomposición de la materia orgánica, ciclado de nutrientes y sudisponibilidad para las plantas. El objetivo del presente estudio fue evaluar la comunidad fúngicade suelos con diferente uso utilizando la técnica PCR-DGGE. Se tomaron muestras de suelo (0-5 y5-20 cm de profundidad) de agricultura continua bajo siembra directa (AC), monte de Acacia sp.(MA) y pastizal natural (PN), en la región pampeana Argentina. La composición de la comunidadde hongos fue analizada utilizando la técnica molecular de la reacción en cadena de la polimerasa(PCR), electroforesis en geles con gradiente desnaturalizante (DGGE). A partir de los perfiles debandas de los geles DGGE se determinaron el número de bandas (S) y el coeficiente de similitudde Jaccard. Los perfiles obtenidos de la amplificación de fragmentos de ADN permitieron detectarespecies únicas en los primeros 5 cm de suelo para los usos de MA, AC y PN, al igual que para MAy PN en los 5 a 20 cm de profundidad. Por otro lado, se observaron fragmentos compartidos entrelos tres usos de suelo. El dendrograma identificó dos grupos, con un nivel de similitud próximo a35%. Los perfiles moleculares determinaron que la comunidad del PN se diferenció de las de MA yAC, los cuales están más cercanos entre sí. En conclusión, la técnica PCR-DGGE permitió determinardiferencias en la composición de las comunidades fúngicas edáficas entre suelos con diferente usoen la región pampeana Argentina.Fungi have a key role in organic matter decomposition, nutrient cycling and nutrient availability to plants. The objective of the present study was to evaluate the fungal community of soils with different uses using the PCR-DGGE technique. Soil samples (0-5 and 5-20 cm depth) were taken from continuous agriculture under no-till (AC), Acacia sp. forest (MA) and prairie (PN) in the pampean region of Argentina. The fungal community was analyzed using the molecular technique polymerase chain reaction (PCR) – denaturing gradient gel electrophoresis (DGGE). The number of bands (S) and Jaccard similarity coefficient were determined from band profiles of DGGE gels. The profiles obtained from amplification of DNA fragments allowed identifying unique species in the first 5 cm of the soil for MA, AC and PN uses as well as for MA and PN from 5 to 20 cm depth. On the other hand, shared fragments were observed among the three soil uses. The dendrogram identified two groups, with similarity coefficient close to 35%. The molecular profiles determined that the PN community differed from those of MA and AC, which are closer to each other. In conclusion, the PCR-DGGE technique allowed determining differences in the composition of edaphic fungal communities between soils with different use in the pampean region of Argentina.Fil: Marcos Valle, Facundo José. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Buenos Aires Sur.; ArgentinaFil: Moreno, Maria Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnolológico Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología. Laboratorio de Biología Funcional y Biotecnología; ArgentinaFil: Silvestro, L. B.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Cientifico Tecnolológico Mar del Plata. Instituto de Investigaciones en Biodiversidad y Biotecnología. Laboratorio de Biología Funcional y Biotecnología; ArgentinaFil: Castellari, Claudia Carla. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce; ArgentinaFil: Diaz Delfino, Alberto. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Buenos Aires Sur.; ArgentinaFil: Andreoli, Yolanda Elina. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Buenos Aires Sur.; ArgentinaFil: Picone, Liliana Inés. Instituto Nacional de Tecnologia Agropecuaria. Centro Regional Buenos Aires Sur.; Argentin

    Excellent Response to OnabotulinumtoxinA: Different Definitions, Different Predictors

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    The identification of patients who can benefit the most from the available preventive treatments is important in chronic migraine. We explored the rate of excellent responders to onabotulinumtoxinA in a multicenter European study and explored the predictors of such response, according to different definitions. A pooled analysis on chronic migraineurs treated with onabotulinumtoxinA and followed-up for, at least, 9 months was performed. Excellent responders were defined either as patients with a ≥75% decrease in monthly headache days (percent-based excellent responders) or as patients with <4 monthly headache days (frequency-based excellent responders). The characteristics of excellent responders at the baseline were compared with the ones of patients with a <30% decrease in monthly headache days. Percent-based excellent responders represented about 10% of the sample, whilst frequency-based excellent responders were about 5% of the sample. Compared with non-responders, percent-based excellent responders had a higher prevalence of medication overuse and a higher excellent response rate even after the 1st and the 2nd injection. Females were less like to be frequency-based excellent responders. Chronic migraine sufferers without medication overuse and of female sex may find fewer benefits with onabotulinumtoxinA. Additionally, the excellent response status is identifiable after the first cycle

    Dust Devil Tracks

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    Dust devils that leave dark- or light-toned tracks are common on Mars and they can also be found on the Earth’s surface. Dust devil tracks (hereinafter DDTs) are ephemeral surface features with mostly sub-annual lifetimes. Regarding their size, DDT widths can range between ∼1 m and ∼1 km, depending on the diameter of dust devil that created the track, and DDT lengths range from a few tens of meters to several kilometers, limited by the duration and horizontal ground speed of dust devils. DDTs can be classified into three main types based on their morphology and albedo in contrast to their surroundings; all are found on both planets: (a) dark continuous DDTs, (b) dark cycloidal DDTs, and (c) bright DDTs. Dark continuous DDTs are the most common type on Mars. They are characterized by their relatively homogenous and continuous low albedo surface tracks. Based on terrestrial and martian in situ studies, these DDTs most likely form when surficial dust layers are removed to expose larger-grained substrate material (coarse sands of ≥500 μm in diameter). The exposure of larger-grained materials changes the photometric properties of the surface; hence leading to lower albedo tracks because grain size is photometrically inversely proportional to the surface reflectance. However, although not observed so far, compositional differences (i.e., color differences) might also lead to albedo contrasts when dust is removed to expose substrate materials with mineralogical differences. For dark continuous DDTs, albedo drop measurements are around 2.5 % in the wavelength range of 550–850 nm on Mars and around 0.5 % in the wavelength range from 300–1100 nm on Earth. The removal of an equivalent layer thickness around 1 μm is sufficient for the formation of visible dark continuous DDTs on Mars and Earth. The next type of DDTs, dark cycloidal DDTs, are characterized by their low albedo pattern of overlapping scallops. Terrestrial in situ studies imply that they are formed when sand-sized material that is eroded from the outer vortex area of a dust devil is redeposited in annular patterns in the central vortex region. This type of DDT can also be found in on Mars in orbital image data, and although in situ studies are lacking, terrestrial analog studies, laboratory work, and numerical modeling suggest they have the same formation mechanism as those on Earth. Finally, bright DDTs are characterized by their continuous track pattern and high albedo compared to their undisturbed surroundings. They are found on both planets, but to date they have only been analyzed in situ on Earth. Here, the destruction of aggregates of dust, silt and sand by dust devils leads to smooth surfaces in contrast to the undisturbed rough surfaces surrounding the track. The resulting change in photometric properties occurs because the smoother surfaces have a higher reflectance compared to the surrounding rough surface, leading to bright DDTs. On Mars, the destruction of surficial dust-aggregates may also lead to bright DDTs. However, higher reflective surfaces may be produced by other formation mechanisms, such as dust compaction by passing dust devils, as this may also cause changes in photometric properties. On Mars, DDTs in general are found at all elevations and on a global scale, except on the permanent polar caps. DDT maximum areal densities occur during spring and summer in both hemispheres produced by an increase in dust devil activity caused by maximum insolation. Regionally, dust devil densities vary spatially likely controlled by changes in dust cover thicknesses and substrate materials. This variability makes it difficult to infer dust devil activity from DDT frequencies. Furthermore, only a fraction of dust devils leave tracks. However, DDTs can be used as proxies for dust devil lifetimes and wind directions and speeds, and they can also be used to predict lander or rover solar panel clearing events. Overall, the high DDT frequency in many areas on Mars leads to drastic albedo changes that affect large-scale weather patterns

    Effect of High-Titer Convalescent Plasma on Progression to Severe Respiratory Failure or Death in Hospitalized Patients with COVID-19 Pneumonia: A Randomized Clinical Trial

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    Importance: Convalescent plasma (CP) has been generally unsuccessful in preventing worsening of respiratory failure or death in hospitalized patients with COVID-19 pneumonia. Objective: To evaluate the efficacy of CP plus standard therapy (ST) vs ST alone in preventing worsening respiratory failure or death in patients with COVID-19 pneumonia. Design, Setting, and Participants: This prospective, open-label, randomized clinical trial enrolled (1:1 ratio) hospitalized patients with COVID-19 pneumonia to receive CP plus ST or ST alone between July 15 and December 8, 2020, at 27 clinical sites in Italy. Hospitalized adults with COVID-19 pneumonia and a partial pressure of oxygen-to-fraction of inspired oxygen (Pao2/Fio2) ratio between 350 and 200 mm Hg were eligible. Interventions: Patients in the experimental group received intravenous high-titer CP (≥1:160, by microneutralization test) plus ST. The volume of infused CP was 200 mL given from 1 to a maximum of 3 infusions. Patients in the control group received ST, represented by remdesivir, glucocorticoids, and low-molecular weight heparin, according to the Agenzia Italiana del Farmaco recommendations. Main Outcomes and Measures: The primary outcome was a composite of worsening respiratory failure (Pao2/Fio2ratio <150 mm Hg) or death within 30 days from randomization. Results: Of the 487 randomized patients (241 to CP plus ST; 246 to ST alone), 312 (64.1%) were men; the median (IQR) age was 64 (54.0-74.0) years. The modified intention-to-treat population included 473 patients. The primary end point occurred in 59 of 231 patients (25.5%) treated with CP and ST and in 67 of 239 patients (28.0%) who received ST (odds ratio, 0.88; 95% CI, 0.59-1.33; P =.54). Adverse events occurred more frequently in the CP group (12 of 241 [5.0%]) compared with the control group (4 of 246 [1.6%]; P =.04). Conclusions and Relevance: In patients with moderate to severe COVID-19 pneumonia, high-titer anti-SARS-CoV-2 CP did not reduce the progression to severe respiratory failure or death within 30 days. Trial Registration: ClinicalTrials.gov Identifier: NCT04716556

    "You have to get wet to learn how to swim" applied to bridging the gap between research into personnel scheduling and its implementation in practice

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    Personnel scheduling problems have attracted research interests for several decades. They have been considerably changed over time, accommodating a variety of constraints related to legal and organisation requirements, part-time staff, flexible hours of staff, staff preferences, etc. This led to a myriad of approaches developed for solving personnel scheduling problems including optimisation, meta-heuristics, artificial intelligence, decision-support, and also hybrids of these approaches. However, this still does not imply that this research has a large impact on practice and that state-of-the art models and algorithms are widely in use in organisations. One can find a reasonably large number of software packages that aim to assist in personnel scheduling. A classification of this software based on its purpose will be proposed, accompanied with a discussion about the level of support that this software offers to schedulers. A general conclusion is that the available software, with some exceptions, does not benefit from the wealth of developed models and methods. The remaining of the paper will provide insights into some characteristics of real-world scheduling problems that, in the author’s opinion, have not been given a due attention in the personnel scheduling research community yet and which could contribute to the enhancement of the implementation of research results in practice. Concluding remarks are that in order to bridge the gap that still exists between research into personnel scheduling and practice, we need to engage more with schedulers in practice and also with software developers; one may say we need to get wet if we want to learn how to swim
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