Effects of Douglas fir stand age on soil chemical properties, nutrient dynamics, and enzyme activity: A case study in Northern Apennines, Italy

The aim of this study was to determine the effect of a Douglas fir plantation along a stand chronosequence in the North Apennine (Italy) on soil carbon and nitrogen stocks, as well as on soil chemical and biochemical properties involved in the nutrients biogeochemical cycle. In 2014, three sites of Douglas fir stands, aged 80, 100, and 120 years, were selected in Vallombrosa forest to study the dynamics of soil nutrients in the ecosystem. Along the Douglas fir chronosequence, general evidence of surface element accumulation was found, including a conspicuous increase of alkaline element with respect to Al, which was attributed to the increase of soil pH along the Douglas fir stand age classes. A general increase of specific enzyme activity (per unit of organic carbon) and functional diversity were observed in the epipedon of the Douglas fir stand over 100 years of age. Moreover, the (chitinase + leucine aminopeptidase) to acid phosphatase ratio progressively increased from 0.15 to 0.31 in the epipedon of the chrononsequence, while the -glucosidase to (chitinase + leucine aminopeptidase) ratio decreased from 1.45 to 0.83, suggesting nitrogen limitation with respect to carbon. In fact, the soil carbon stock progressively increased along the chronosequence, in the epipedon from 17 to 53 Mg C ha(-1) and in the endopedon from 17 to 37 Mg C ha(-1). Conversely, the soil nitrogen stock increased from 1.2 to 2.4 Mg N ha(-1), but not over the 100-year-old stand class. In conclusion, soil organic matter accumulation became sufficient to define the umbric horizon in the Northern Apennines when the Douglas fir plantation reached the age of 100 years. Over this age class of plants, a limitation of soil nitrogen may occur, affecting enzyme activities regulating the biogeochemical cycle of nutrients

GaN LNAs for Robust Receiving Systems in Radar and Space Applications

In this contribution a series of integrated circuits and methodologies, purposely developed for application in microwave receiving subsystems, will be presented. The integrated circuits, realized in GaN integrated technologies by different suppliers, find their applications in telecom systems as well as in RADAR ones, mainly for space-based apparatuses. The respective performance, as well as the key design methods will be presented in the contribution for bandwidths ranging from S-Band up to K-Band

Influence of baking conditions and formulation on furanic derivatives, 3-methylbutanal and hexanal and other quality characteristics of lab-made and commercial biscuits

Biscuit baking can cause the formation of heat-related toxic compounds, mainly through the Maillard reaction, including some volatile organic compounds (VOCs) that are potentially carcinogenic to humans. This study investigates the effects of different baking conditions and recipes on quality characteristics (moisture, water activity, colour, texture) and on the concentration of some VOCs (furfural, furfuryl acetate, 5-methylfurfural, furfuryl alcohol, 3-methylbutanal, hexanal) in biscuits. Specifically, lab-made biscuits baked under static and ventilated conditions and three commercial biscuit types categorised as shortbreads with eggs, with chocolate chips and dry petits were evaluated. Concerning the lab-made biscuits, the ventilated mode resulted in faster baking and a slightly lower concentration of investigated VOCs compared to the static mode. Besides the process conditions, the recipe also played a role in the final quality and target volatiles, whose concentrations were lower in dry petits than in shortbreads, which are characterised by higher sugar and fat contents

Correction to: Quality traits of raw and cooked cupped oysters

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Computer Percolation Models for Espresso Coffee: State of the Art, Results and Future Perspectives

Coffee is one of the most consumed beverages in the world. This has two main consequences: a high level of competitiveness among the players operating in the sector and an increasing pressure from the supply chain on the environment. These two aspects have to be supported by scientific research to foster innovation and reduce the negative impact of the coffee market on the environment. In this paper, we describe a mathematical model for espresso coffee extraction that is able to predict the chemical characterisation of the coffee in the cup. Such a model has been tested through a wide campaign of chemical laboratory analyses on espresso coffee samples extracted under different conditions. The results of such laboratory analyses are compared with the simulation results obtained using the aforementioned model. The comparison shows a close agreement between the real and in silico extractions, revealing that the model is a very promising scientific tool to take on the challenges of the coffee market

Discrimination of filter coffee extraction methods of a medium roasted specialty coffee based on volatile profiles and sensorial traits

An untargeted gas chromatography-mass spectrometry (GC-MS) approach combined with sensory analysis was used to present the effects of different extraction methods (i.e., Pure Brew, V60, AeroPress, and French Press) on specialty graded Coffea arabica from Kenya. Partial Least Square Discriminant analysis and hierarchical clustering were applied as multivariate statistical tools in data analysis. The results showed good discrimination and a clear clustering of the groups of samples based on their volatile profiles. Similarities were found related to the filter material and shape used for the extraction. Samples extracted with paper filters (V60 and AeroPress) resulted in higher percentages of caramel-, and flowery-related compounds, while from metal filter samples (Pure Brew and French Press), more fruity and roasted coffees were obtained. Discriminant analysis allowed the identification of eight compounds with a high VIP (variable important in projection) discriminant value (i.e., >1), with 2-furanmethanol being the main feature in discrimination. Sensorial analyses were carried out through an expert panel test. The main evaluations revealed the French Press system as the lowest-scored sample in all the evaluated parameters, except for acidity, where its score was similar to V60. In conclusion, the data obtained from GC-MS analyses were in line with the sensorial results, confirming that the extraction process plays a fundamental role in the flavor profile of filter coffee beverages

Seismically induced ground effects of the 1805, 1930 and 1980 earthquakes in the Southern Apennines (Italy

Seismically induced environmental effects (in particular, surfacefaults, ground cracks, slope failures, liquefaction, soil compaction, hydrological changes, tsunamis) are assumed to provide fundamentalinformation on the earthquake size and its intensity field, crucial for a more efficient seismic hazard assessment. Accordingly, this study is aimed at substantiating this assumption by showing that the knowledge about ground effects acquired in recent earthquakes, when combined with that illustrated in historical documents, allows to buildan improved picture of historic seismic events, with respect to that usually provided by the solely damage-based macroseismic scales. In this perspective, the environmental effects are analysed and cataloguedof three of the most ruinous earthquakes in Southern Italy of the last two centuries: the July 26,1805, Molise event (XI MCS, M 6.8), the July 23, 1930, Irpinia event (X MCS, M 6.7), and the November 23, 1980 Campania-Basilicata event (X MSK, Ms 6.9). The distribution of the earthquake environmental effects, in particular their distance from the known or supposed causative fault, has been investigated to obtain a more detailed and comprehensive picture of the macroseismic field, a key parameter in seismic hazard assessment and seismic zonation. KEY WORDS: historical seismicity, intensity, ground effects, earthquak