1,721,232 research outputs found
Purification, Characterization and Photodegradation studies of modified sepia melanin (Sepia officinalis). Determination of Eumelanin content in fibers from Alpaca (Vicugna pacos).
No full textCurrently melanins are still enigmatic bio-pigments bearing a structure as well as methods of determination not clearly fixed by the international scientific community. In many respects melanins are unique among biopolymers. The other essential biopolymers, that is proteins, nucleic acids and carbohydrates are chemically well characterized and can be determined using well established methodologies. On the other hand, we still do not have a method of accurately determination of melanin. Basically, the classes of mammalian melanins exist in two chemically distinct forms: the brown to black Eumelanin (Eu) and the yellow to reddish-brown Pheomelanin (Pheo). It is believed that melanin has a photoprotective role in animals. Although melanin has been postulated to act as a cellular antioxidant, little is known about the molecular mechanism of melanin photo-protection. An oxidative insult can produce modifications in the physiochemical characteristics of melanin and compromise its photo protective function. Sepia melanin (Sepia officcinalis)represents 98 % of Eumelanin pigment, and is thus used as standard material for the analysis of melanic black. Commercial sepia melanin (very expensive) is purified according to an unknown procedure. In our research, we carried out studies on the extraction and purification of sepia melanin by acid treatment using different concentrations of hydrochloric acid, under mechanic or ultrasonic agitation. This proved effective in producing a high degree purity sepia melanin then fully characterized by Elemental Analysis (EA), Ultraviolet-Visible (UV-VIS) and Infrared (IR) spectroscopy, Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) for metal ion analysis and quantitative studies of Eu polymers for chemical degradation to PTCA and PDCA by High Performance Liquid Chromatography (HPLC). A first modification of sepia melanin using hydrochloric acid afforded the hydrolysis of the sepia melanin while a second modification, obtained adding different salts, resulted in melanin in the salt form. Sepia melanin stability was studied by photodegradation measurements, UV-Vis absorbance spectra of different melanin solutions were measured before and after ultraviolet exposure. The difference spectra reveal that following ultraviolet exposure, a photo-bleaching effect can be observed in this range. The irradiation with ultraviolet radiation induced significant photochemical alterations in the sepia melanin. The obtained results can be used to extrapolate melanin degradation rates in vivo conditions, including the potential limits of its protective effect in humans
Sfuggire le gelate in vigneto con potature tardive
No full textNell’uva da tavola un andamento climatico non ottimale può causare una riduzione nelle rese e ritardare la maturazione dei grappoli determinando una variazione negativa dei prezzi sul mercato; a potatura può rivelarsi un valido alleato per poter mitigare e alla lunga modellare alcuni aspetti del ciclo annuale della vite
Macro-moths as possible assessment endpoints for non-target effects of Bt-maize pollen: A faunistic study in three Italian protected areas
No full textLepidoptera are the phytophagous group most at risk of impact by insect-resistant genetically modified (GM) plants since most of these crops have been developed to express toxins to specifically target lepidopteran pests. In the case of Bt-maize cultivation, pollen grains released by GM plants could dust larval host plants growing inside or nearby maize fields, thus leading to the exposure of caterpillars to the Cry toxins. This way of exposure has been studied mainly for butterflies, whereas moths, in spite of their great diversity and abundance, were rarely considered. To evaluate the potential exposure of moth species to maize pollen in absence of Cry-expressing plants, macro-moths were sampled by means of light traps in three protected areas of Northern, Central and Southern Italy where conventional maize is among the main crops. Light traps were activated in two consecutive years (2010- 11) from the beginning of June to the end of July, a period that encompasses the anthesis of most maize cultivars grown in Italy. Overall, 11446 individuals belonging to 201 species and nine families were collected. Given that larvae of several sampled species are likely to match the criteria of potential exposure to maize pollen and susceptibility to Cry toxins, macro-moths might be considered among the potential assessment endpoints for environmental risk assessment of GM plants, especially in the vicinity of protected areas. © 2017, Bulletin of Insectology. All rights reserved
Exploring the Grape Agrivoltaic System: Climate Modulation and Vine Benefits in the Puglia Region, Southeastern Italy
No full textClimate change poses significant challenges to agriculture, a sector with a long-standing tradition in the Mediterranean basin. The region faces altered rainfall patterns, extreme temperatures, aridification, loss of biodiversity, and changes in crop yield and quality. These impacts, combined with intensive farming practices, threaten long-term agricultural sustainability. This study investigates agrivoltaics (AVs), a dual-use technology that integrates solar energy production (photovoltaic panels) with agriculture, as a potential solution to enhance resilience and adaptation of crops. Research at an AV system in Puglia (Southeastern Italy), combined with grapevine (Vitis vinifera L.), assessed soil moisture, temperature, and microclimate conditions together with vine yield and fruitfulness. Results showed that shading from photovoltaic panels increased soil moisture and moderated soil temperature, thus benefiting crops. Vines beneath the panels yielded more grapes (+277%) than in the full sun, confirmed by even the better bud fruitfulness of the shaded canes. While panels had minimal impact on air temperature, they reduced wind speed and vapor pressure deficit, creating a better microenvironment for vines. Spectral analysis revealed an increase in UV and blue light under the panels, potentially affecting photosynthesis. The AV system also produced substantial electricity, more than 90% compared to a ground-mounted system, demonstrating its dual-use application. The higher land equivalent ratio (LER) achieved by the AV system (3.54) confirmed that such systems can be advantageous in areas with a Mediterranean climate, allowing crop and energy production on the same land
Purification, characterization and analysis of sepia melanin from commercial sepia ink (Sepia officinalis)
No full textAt the moment melanins are still enigmatic bio-pigments with structure and determination methods not clearly understood for the international scientific community. Among biopolymers, melanins are unique in many aspects. Some essential biopolymers (proteins, nucleic acids and carbohydrates) are chemically well characterized and can be determined using well established analytical methodologies. On the contrary, no available methods allow us to accurately determine melanin, mostly due to the intrinsic chemical properties of melanins. These pigments, in fact, are insoluble in a broad range of solvents and pH as well as difficult to purify as a result of the heterogeneity in their structural features. Mammalian melanins exist in two chemically distinct forms: the brown to black Eumelanin and the yellow to reddish-brown Pheomelanin. Sepia melanin obtained from Sepia officinalis consists of more than 98% of Eumelanin and is therefore used as standard material in the analysis of melanic black. Commercial sepia melanin is purified according to an undescribed procedure. In this research, extraction and purification studies were carried out on sepia melanin using a hydrochloric acid (0.5-3.0 M) treatment under mechanical or ultrasonic agitation. A high degree purity sepia melanin was obtained and further characterized using Elemental Analysis (EA), Ultraviolet-Visible (UV-VIS) and Infrared (IR) spectroscopy and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) for metal ion analysis. Finally, quantitative studies of the chemical degradation of Eu polymers to Pyrrole-2,3,5-tricarboxylic acid (PTCA) and Pyrrole-2,3-dicarboxylic acid (PDCA) by High Performance Liquid Chromatography (HPLC) were performed. The procedure we developed can be used to obtain a considerably less expensive sepia melanin which could prove important as a standard in future determinations of eumelanin and pheomelanin as well as in a vast field of scientific and industrial applications in such fields as human and veterinary medicine, pharmacology and cosmetics
The fig (Ficus carica L.): varietal evolution from Asia to Puglia region, southeastern Italy
Full text linkThe fig represents one of the oldest and widespread species in the Mediterranean basin, and thanks to man-made selections, it is possible to survey numerous varieties currently used for both main crop and brebas production. The fig is often associated with the birth of horticulture in Mediterranean and Near Asia areas. Figs were probably carried to southern Italy by Phoenicians and successively by Greeks and played an important role in Roman society. Puglia was in the past the most important region in southern Italy to produce figs and especially brebas (first crop), thanks to the excellent qualitative aspects of some varieties such as 'Petrelli' (syn. "Fiorone di S. Giovanni," "Fiorone di S. Antonio") and 'Domenico Tauro' that are mainly cultivated in the provinces of Bari and Brindisi. Main crop production, on the other hand, has always been based on the 'Dottato' variety, which was mainly used for drying and is partly consumed fresh, but also processed into jams and marmalades. There are numerous 'minor' varieties, which allow Puglia to be among the regions in the world with the greatest fig biodiversity, a kind of living repository grown during the centuries and in the last years rediscovered. However, the consumption and trade are exclusively at the local level, due to limited resistance to handling and shipping of such fruit; only a limited amount is destined to export. The main fig varieties cultivated in Puglia allow a wide ripening calendar starting from the first 10 days of June for brebas (often at the end of May) and ending in late September-October with late ripening varieties. The purpose of this mini review is to highlight the high degree of biodiversity that exists in Puglia region since many centuries, and the importance that this ancient crop could have in modern fruit growing, as it was once a key player in market scenarios in many Mediterranean and Near Asia countries. The fig biodiversity could be used either for fresh and processed consumption or for breeding programs for new varieties with desired traits and qualities
Fruit Crop Species with Agrivoltaic Systems: A Critical Review
Full text linkAs the world seeks alternatives to fossil fuels, agrivoltaics offer a promising solution by integrating solar panels with farming practices. This review examines three key agrivoltaic setups—static tilted, full-sun tracking, and agronomic tracking—dissecting their engineering features’ roles in optimizing both the electricity yield and the fruit productivity of some fruit crops. We emphasize the microclimatic modifications induced by agrivoltaic systems, mainly encompassing changes in solar radiation, air temperature, humidity, and wind. The data collected in this survey reveal a strong spatial heterogeneity distribution over different locations and a significant influence on fruit crops’ growth, yield, and quality, with variations among species. Such findings on the overall performance recommend a 30% shading threshold to prevent substantial declines in fruit characteristics, i.e., fruit yield and quality. Shading conditions over this threshold influence the leaf morphophysiological characteristics, impacting the photosynthesis capacity and fruit dry matter accumulation. This emphasizes the importance of further investigation into spectral radiation quality and carbon assimilation kinetics as daily responses for different fruit species to be cultivated in such new environments. Starting from this point, this review underscores the need to extend studies on various fruit crops, particularly those cultivated in semi-arid horticultural regions (i.e., for saving water), and suggests the use of comprehensive and standardized indicators for comparability across studies. Finally, the authors conclude that engineering improvements, along with new research programs on agrivoltaic systems, could lead to agricultural, environmental, and economic sustainability, as well as their practical implementation and attractiveness to farmers in the coming years
Antaño “Countryside” : La resistencia local frente al desarrollo de la ciudad industrial entre fines del siglo XIX y principios del siglo XX
Full text linkLa reciente divulgación sobre los estudios y las exposiciones organizadas sobre el ruralismo realizadas por AMO ha reavivado los debates sobre las lógicas de urbanización y los medios para la construcción de un paisaje más cercano a la naturaleza. En este trabajo tomaremos de ejemplo lo sucedido durante fines del siglo XIX y principios del siglo XX, entendiendo tal época como el momento de mayor crisis para el desarrollo de las ciudades y de las urbanizaciones industriales-capitalistas posterior al cambio de paradigma que significó la creación del motor de combustión interna, con sus consecuentes migraciones urbanas. Las oportunidades laborales que motivaron dichas migraciones se transformaron en formación de tugurios y hacinamientos peligrosos para la salubridad general, lo que generó la formación de numerosas crisis sociales que se verían paulatinamente reposadas por un principal instrumento: la vivienda obrera. De esta manera, ahondaremos las relaciones entre la vivienda obrera con los diversos estilos y tipos arquitectónicos, y, a su vez, la construcción de imaginarios urbanos como resistencia al avance de la modernización. Esta revisión de nuestro pasado urbano, a partir de las semejanzas con los debates contemporáneos, creemos que nos brindaran herramientas incuestionables para la resolución y el análisis de nuestro futuro.Fil: Magarelli, Lucio. Universidad de Buenos Aires; Argentina
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