2,799 research outputs found

    Líneas de girasol de la EEA Pergamino

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    Se analizaron tres grupos de líneas de girasol (Helianthus annuus) de la EEA Pergamino del INTA. Grupo 1: líneas derivadas de los compuestos P1, P2, P4, PGRK y KLM liberadas en la década del 90. Grupo 2: líneas GP logradas de cruzas entre las del grupo 1 con otras fuentes, liberadas a partir del 2001. Grupo 3: líneas AO (contenido de oleico > 80%) derivadas de materiales del North Dakota y de cruzas con materiales locales. Se analizaron los siguientes caracteres: número de aquenios por capítulo, peso de cien aquenios, porcentaje de pepita y aceite, altura de planta y número de días desde siembra a floración. El objetivo fue evaluar la variabilidad del germoplasma entre grupos y las asociaciones entre caracteres dentro de cada grupo, para identificar el idiotipo y las características diferenciales. El efecto de la selección se manifestó claramente al comparar los grupos. En el Grupo 1, la selección se efectuó principalmente por rendimiento de semilla y en los Grupos 2 y 3, se dirigió a la mejora del contenido porcentual de aceite y contenido porcentual de oleico respectivamente. Las líneas del Grupo 2 y Grupo 3 (AO) superaron en contenido de aceite a las del Grupo 1, las cuales fueron de mayor altura y peso de aquenio. Dentro de cada grupo se identificaron de 4 a 6 subgrupos caracterizados por los objetivos del mejoramiento y diferenciándose líneas independientes derivadas por objetivos de selección indirecta. El germoplasma evaluado podría incorporarse a diferentes “backgrounds” genéticos según los objetivos del mejoramiento

    Strain Measurement on Composites: Errors due to Rosette Misalignment

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    Electrical resistance strain gauges are increasingly used for the determination of the strain field in composite components. The effect of the angular misalignment of a strain gauge rosette on the determination of the strains in a composite material is investigated in this paper. The theoretical analysis shows that the strain error along the principal material directions depends on the difference of principal strains, on the angular misalignment of the rosette and on the angle between the maximum principal strain and the fibre direction. The paper also shows experimental evidence for the theoretical analysis

    Multiple approach to identify bacteria into archaeological waterlogged wood

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    This study was carried out in collaboration with Soprintendenza del Mare (SM) that started, since 2004, to plan and realize underwater archaeological parks, such as in the Sicilian islands of Pantelleria (Gadir), Levanzo (Cala Minnola), Ustica (Falconiera), Panarea (Basiluzzo) and Filicudi (Capo Graziano). In situ conservation, as well as virtual exhibitions of the same topics, can contribute to ensure the protection and best fruition of underwater cultural heritage. The focus of this study was the identification of bacterial colonies in waterlogged wood samples from the rostrum of a excellent workmanship, that is very likely one of the wrecks attributed to Sextus Pompey fleet (36 BC) and discovered in Acqualadroni, Messina, Sicily, Italy (2008). Samples were analyzed by light and Scanning Electron Microscopy (SEM), in vitro culture and molecular technique (DNA base techniques). The results, focused on bacterial consortia, allowed us to reveal the presence of Pseudomonas sp., Sphingomonas sp., Xanthomonas sp. besides Marinobacter sp. and Desulforudis audaxviator. A prompt and accurate characterization of bacterial colonization represents one of the preliminary step in preservation/restoration projects, especially for waterlogged wood since the metabolic activity of specific bacteria induce and accelerate the deterioration processes. Although it is reported in a case study, this multiple approach is useful for reveal and identify bacterial colonizing both organic and inorganic artifacts.This study was carried out in collaboration with Soprintendenza del Mare (SM) that started, since 2004, to plan and realize underwater archaeological parks, such as in the Sicilian islands of Pantelleria (Gadir), Levanzo (Cala Minnola), Ustica (Falconiera), Panarea (Basiluzzo) and Filicudi (Capo Graziano). In situ conservation, as well as virtual exhibitions of the same topics, can contribute to ensure the protection and best fruition of underwater cultural heritage. The focus of this study was the identification of bacterial colonies in waterlogged wood samples from the rostrum of a excellent workmanship, that is very likely one of the wrecks attributed to Sextus Pompey fleet (36 BC) and discovered in Acqualadroni, Messina, Sicily, Italy (2008). Samples were analyzed by light and Scanning Electron Microscopy (SEM), in vitro culture and molecular technique (DNA base techniques). The results, focused on bacterial consortia, allowed us to reveal the presence of Pseudomonas sp., Sphingomonas sp., Xanthomonas sp. besides Marinobacter sp. and Desulforudis audaxviator. A prompt and accurate characterization of bacterial colonization represents one of the preliminary step in preservation/restoration projects, especially for waterlogged wood since the metabolic activity of specific bacteria induce and accelerate the deterioration processes. Although it is reported in a case study, this multiple approach is useful for reveal and identify bacterial colonizing both organic and inorganic artifacts

    Venous, Arterial, and Neuropathic Leg Ulcers With Emphasis on the Geriatric Population.

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    Leg ulcers are a common and often serious problem in older adults. Underlying conditions that increase risk include age-related increases in chronic venous insufficiency, peripheral artery disease, connective tissue and autoimmune conditions, reduced mobility, and diabetes mellitus (DM). Geriatric patients have a higher risk of multiple wound-related complications including infection, cellulitis, ischemia, and gangrene, any of which may lead to further complications including amputation. The very presence of these lower extremity ulcers in the elderly negatively impacts their quality of life and ability to function. Understanding and early identification of the underlying conditions and wound features are important for effective ulcer healing and complication mitigation. This targeted review focuses on the three most common types of lower extremity ulcers: venous, arterial, and neuropathic. The goal of this paper is to characterize and discuss the general and specific aspects of these lower extremity ulcers and their relevancy and impact on the geriatric population. The top five main results of this study can be summarized as follows. (1) Venous ulcers, caused by inflammatory processes secondary to venous reflux and hypertension, are the most common chronic leg ulcer in the geriatric population. (2) Arterial-ischemic ulcers are mainly due to lower extremity vascular disease, which itself tends to increase with increasing age setting the stage for an age-related increase in leg ulcers. (3) Persons with DM are at increased risk of developing foot ulcers mainly due to neuropathy and localized ischemia, both of which tend to increase with advancing age. (4) In geriatric patients with leg ulcers, it is important to rule out vasculitis or malignancy as causes. (5) Treatment is best made on a case-by-case basis, considering the patient\u27s underlying condition, comorbidities, overall health status, and life expectancy

    Long-term evolution of the heliospheric magnetic field inferred from cosmogenic 44^{44}Ti activity in meteorites

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    Typical reconstructions of historic heliospheric magnetic field (HMF) BHMFB_{\rm HMF} are based on the analysis of the sunspot activity, geomagnetic data or on measurement of cosmogenic isotopes stored in terrestrial reservoirs like trees (14^{14}C) and ice cores (10^{10}Be). The various reconstructions of BHMFB_{\rm HMF} are however discordant both in strength and trend. Cosmogenic isotopes, which are produced by galactic cosmic rays (GCRs) impacting on meteoroids and whose production rate is modulated by the varying HMF convected outward by the solar wind, may offer an alternative tool for the investigation of the HMF in the past centuries. In this work, we aim to evaluate the long-term evolution of BHMFB_{\rm HMF} over a period covering the past twenty-two solar cycles by using measurements of the cosmogenic 44^{44}Ti activity (τ1/2=59.2±0.6\tau_{1/2} = 59.2 \pm 0.6 yr) measured in 20 meteorites which fell between 1766 and 2001. Within the given uncertainties, our result is compatible with a HMF increase from 4.870.30+0.244.87^{+0.24}_{-0.30} nT in 1766 to 6.830.11+0.136.83^{+0.13}_{-0.11} nT in 2001, thus implying an overall average increment of 1.960.35+0.431.96^{+0.43}_{-0.35} nT over 235 years since 1766 reflecting the modern Grand maximum. The BHMFB_{\rm HMF} trend thus obtained is then compared with the most recent reconstructions of the near-Earth heliospheric magnetic field strength based on geomagnetic, sunspot number and cosmogenic isotope data.Comment: Accepted for publication in Astronomy and Astrophysic

    Extrafloral-nectar based partner manipulation in plant-ant relationship

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    Plant–ant interactions are generally considered as mutualisms, with both parties gaining benefits from the association. It has recently emerged that some of these mutualistic associations have, however, evolved towards other forms of relationships and, in particular, that plants may manipulate their partner ants to make reciprocation more beneficial, thereby stabilizing the mutualism. Focusing on plants bearing extrafloral nectaries, we review recent studies and address three key questions: (i) how can plants attract potential partners and maintain their services; (ii) are there compounds in extrafloral nectar that could mediate partner manipulation; and (iii) are ants susceptible to such compounds? After reviewing the current knowledge on plant–ant associations, we propose a possible scenario where plant-derived chemicals, such as secondary metabolites, known to have an impact on animal brain, could have evolved in plants to attract and manipulate ant behaviour. This new viewpoint would place plant–animal interaction in a different ecological context, opening new ecological and neurobiological perspectives of drug seeking and use
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