Fruit volatile analysis using an electronic nose.

Numerous and diverse physiological changes occur during fruit ripening, including the development of a specific volatile blend that characterizes fruit aroma. Maturity at harvest is one of the key factors influencing the flavor quality of fruits and vegetables. The validation of robust methods that rapidly assess fruit maturity and aroma quality would allow improved management of advanced breeding programs, production practices and postharvest handling. Over the last three decades, much research has been conducted to develop so-called electronic noses, which are devices able to rapidly detect odors and flavors. Currently there are several commercially available electronic noses able to perform volatile analysis, based on different technologies. The electronic nose used in our work (zNose, EST, Newbury Park, CA, USA), consists of ultra-fast gas chromatography coupled with a surface acoustic wave sensor (UFGC-SAW). This technology has already been tested for its ability to monitor quality of various commodities, including detection of deterioration in apple; ripeness and rot evaluation in mango; aroma profiling of thymus species; C(6) volatile compounds in grape berries; characterization of vegetable oil and detection of adulterants in virgin coconut oil. This system can perform the three major steps of aroma analysis: headspace sampling, separation of volatile compounds, and detection. In about one minute, the output, a chromatogram, is produced and, after a purging cycle, the instrument is ready for further analysis. The results obtained with the zNose can be compared to those of other gas-chromatographic systems by calculation of Kovats Indices (KI). Once the instrument has been tuned with an alkane standard solution, the retention times are automatically converted into KIs. However, slight changes in temperature and flow rate are expected to occur over time, causing retention times to drift. Also, depending on the polarity of the column stationary phase, the reproducibility of KI calculations can vary by several index units. A series of programs and graphical interfaces were therefore developed to compare calculated KIs among samples in a semi-automated fashion. These programs reduce the time required for chromatogram analysis of large data sets and minimize the potential for misinterpretation of the data when chromatograms are not perfectly aligned. We present a method for rapid volatile compound analysis in fruit. Sample preparation, data acquisition and handling procedures are also discussed

A general theorem on the divergence of vortex beams

The propagation and divergence properties of beams carrying orbital angular momentum (OAM) play a crucial role in many applications. Here we present a general study on the divergence of optical beams with OAM. We show that the mean absolute value of the OAM imposes a lower bound on the value of the beam divergence. We discuss our results for two different definitions of the divergence, the so called rms or encircled-energy. The bound on the rms divergence can be expressed as a generalized uncertainty principle, with applications in long-range communication, microscopy and 2D quantum systems.Comment: RevTex, published versio

Functional characterization and structure-guided mutational analysis of the transsulfuration enzyme cystathionine γ-lyase from toxoplasma gondii

Sulfur-containing amino acids play essential roles in many organisms. The protozoan parasite Toxoplasma gondii includes the genes for cystathionine β-synthase and cystathionine γ-lyase (TgCGL), as well as for cysteine synthase, which are crucial enzymes of the transsulfuration and de novo pathways for cysteine biosynthesis, respectively. These enzymes are specifically expressed in the oocyst stage of T. gondii. However, their functionality has not been investigated. Herein, we expressed and characterized the putative CGL from T. gondii. Recombinant TgCGL almost exclusively catalyses the α,γ-hydrolysis of L-cystathionine to form L-cysteine and displays marginal reactivity toward L-cysteine. Structure-guided homology modelling revealed two striking amino acid differences between the human and parasite CGL active-sites (Glu59 and Ser340 in human to Ser77 and Asn360 in toxoplasma). Mutation of Asn360 to Ser demonstrated the importance of this residue in modulating the specificity for the catalysis of α,β-versus α,γ-elimination of L-cystathionine. Replacement of Ser77 by Glu completely abolished activity towards L-cystathionine. Our results suggest that CGL is an important functional enzyme in T. gondii, likely implying that the reverse transsulfuration pathway is operative in the parasite; we also probed the roles of active-site architecture and substrate binding conformations as determinants of reaction specificity in transsulfuration enzymes

One-way quantum computation via manipulation of polarization and momentum qubits in two-photon cluster states

Four-qubit cluster states of two photons entangled in polarization and linear momentum have been used to realize a complete set of single qubit rotations and the C-NOT gate for equatorial qubits with high values of fidelity. By the computational equivalence of the two degrees of freedom our result demonstrate the suitability of two photon cluster states for rapid and efficient one-way quantum computing.Comment: RevTex4, 4 pages, 3 figure

Evaluation of Multispectral Data Acquired from UAV Platform in Olive Orchard

Precision agriculture is a management strategy to improve resource efficiency, production, quality, profitability and sustainability of the crops. In recent years, olive tree management is increasingly focused on determining the correct health status of the plants in order to distribute the main resource using different technologies. In the olive grove, the focus is often on the use of multispectral information from UAVs (Unmanned Aerial Vehicle), but it is not known how important spectral and biometric information actually is for the agronomic management of the olive grove. The aim of this study was to investigate the ability of multispectral data acquired from a UAV platform to predict nutritional status, biometric characteristics, vegetative condition and production of olive orchard as tool to DSS. Data were collected on vegetative characteristics closely related to vigour such as trunk cross-sectional area (TCSA), Nitrogen concentration of the leaves, canopy area and canopy volume. The production was collected for each plant to create an accurate yield map. The flight was carried out with a UAV equipped with a multispectral camera, at an altitude of 50 m and with RTK correction. The flight made it possible to determine the biometric condition and the spectral features through the normalized difference vegetation index (NDVI). The NDVI map allowed to determine the canopy area. The Structure for Motion (SfM) algorithm allow to determine the 3D canopy volume. The experiment showed that the NDVI was able to determine with high accuracy the vegetative characteristic as canopy area (r = 0.87 ***), TCSA (r = 0.58 ***) and production (r = 0.63 ***). The vegetative parameters are closely correlated with the production, especially the canopy area (r = 0.75 ***). Data clustering showed that the production of individual plants is closely dependent on leaf nitrogen concentration and vigour status

Unmanned aerial vehicle and proximal sensing of vegetation indices in olive tree (Olea europaea)

Remote and proximal sensing platforms at the service of precision olive growing are bringing new development possibilities to the sector. A proximal sensing platform is close to the vegetation, while a remote sensing platform, such as unmanned aerial vehicle (UAV), is more distant but has the advantage of rapidity to investigate plots. The study aims to compare multispectral and hyperspectral data acquired with remote and proximal sensing platforms. The comparison between the two sensors aims at understanding the different responses their use can provide on a crop, such as olive trees having a complex canopy. The multispectral data were acquired with a DJI multispectral camera mounted on the UAV Phantom 4. Hyperspectral acquisitions were carried out with a FieldSpec® HandHeld 2™ Spectroradiometer in the canopy portions exposed to South, East, West, and North. The multispectral images were processed with Geographic Information System software to extrapolate spectral information for each cardinal direction’s exposure. The three main Vegetation indices were used: normalized difference vegetation index (NDVI), normalized difference red-edge index (NDRE), and modified soil adjusted vegetation index (MSAVI). Multispectral data e could describe the total variability of the whole plot differentiating each single plant status. Hyperspectral data were able to describe vegetation conditions more accurately; they appeared to be related to the cardinal exposure. MSAVI, NDVI, and NDRE showed correlation r =0.63**, 0.69**, and 0.74**, respectively, between multispectral and hyperspectral data. South and West exposures showed the best correlations with both platforms

Effect of water deficit irrigation on vegetative growth of young cheery trees (Prunus avium L.)

En cerezo, plantas con excesivo vigor son poco precoces, poco productivas y de difícil manejo. El exceso de vigor podría ser controlado con estrategias de riego deficitario controlado (RDC). Durante dos años se realizó un ensayo de RDC en un monte frutal comercial joven y de alto vigor de cerezos Bing, plantado en suelo árido poco profundo y regado por goteo. Se evaluó la respuesta a distintos regímenes de riego sobre el crecimiento de brotes terminales y vigorosos, área y peso seco foliar, y crecimiento de tronco. Los tratamientos de riego fueron: T1 = 100%, T2 = 75% y T3 = 50% de la evapotranspiración máxima (ETc full), respectivamente. Se midió periódicamente el estado hídrico de la planta a través del potencial agua del tallo a mediodía y el estado hídrico del suelo mediante gravimetría. En T3 disminuyó la longitud de brotes, número y longitud de entrenudos, número de hojas, área foliar y peso seco foliar, y área de tronco. En T2 disminuyó la longitud de brotes y entrenudos y el área de sección de tronco. El potencial hídrico del tallo a mediodía fue un buen indicador del estado hídrico de las plantas. En cerezos, un ajuste preciso del nivel de restricción hídrica puede ser una estrategia de manejo para controlar vigor y para ahorrar importantes cantidades de agua.Vigorous cherry tree orchards are less precocious and productive, and difficult to manage. Regulated deficit irrigation (RDI) can be used as a strategy to control excessive vigor. In order to evaluate vegetative growth a two year RDI experiment was conducted in a commercial Bing sweet cherry orchard, planted in dry shallow soil with drip irrigation. The treatments were as follows: T1 = 100%, T2 = 75% and T3 = 50% of full ETc. Terminal and vigorous shoot length, leaf area, leaf dry weight and trunk cross-sectional area were evaluated. Plant water status was periodically measured by midday stem water potential and soil water content by gravimetric techniques. In T3 shoot length, number and length of internodes, number, area, and dry weight of leaves, and trunk area significantly decreased. In T2 shoot, internode and trunk area growth decreased, but the other variables were less affected. Midday stem water potential resulted a good indicator of plant water status. In cheery orchards a carefully managed RDI can be used to control vigor, saving significant amounts of water at the same time.Fil: Podestá, Lidia. Universidad Nacional de Cuyo. Facultad de Ciencias AgrariasFil: Sánchez, Enrique E.. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Alto ValleFil: Vallone, Rosana. Instituto Nacional de Tecnología Agropecuaria (Argentina). Estación Experimental Agropecuaria Mendoza.Fil: Morábito, José. Instituto Nacional del Agua (Argentina). Centro Regional Andin

ADRANOS: A numerical tool developed to analyse coolant operating conditions of the EU-DEMO divertor

In the context of the activities of the EUROfusion action, the University of Palermo has carried out a research campaign to evaluate the thermal-hydraulic performance of the EU-DEMO divertor Single-Circuit Cooling (SCC) option. Given the exceptional geometric complexity of this divertor design, the search for coolant operating conditions that comply with the applicable design constraints cannot be performed by relying on detailed 3D computational fluid-dynamic calculations. For this purpose, the Advanced Divertor paRametric Analysis for coolaNt Operating Scenarios (ADRANOS) code has been developed. It is a novel numerical tool capable of quickly assessing the thermofluid-dynamic behaviour of the divertor cooling circuit with reduced computational cost, predicting the divertor performance map at different coolant inlet conditions and mass flow rates, and allowing for the effortless study of different circuit topologies. This study introduces the ADRANOS modelling approach, describes its validation process, and demonstrates its application to various configurations of the SCC divertor option. The results obtained showed that it is possible to find suitable coolant operating conditions characterized by low temperature and high pressure, posing a challenge for the adoption of Eurofer as a structural material

'ACCORD' e-Platform: Development and evaluation of an innovative multicultural training for school professionals

The study aims at describing the development, application and evaluation of ACCORD, an innovative e-platform offering a free-accessible tailored multicultural training for school professionals through the application of current ICT research (e-learning, mobility, internet, artificial intelligence). The eplatform provided school professionals with a dedicated Massive Online Open Course (MOOC) and a Serious Game (SG), embedded within it, useful to enhance and (self-)evaluate their intercultural competences and negotiation abilities. Technological, Psychological, and Pedagogical models and approaches underpinned the methodology driving the creation of the e-platform contents. Following a pilot test, the edited version of the e-platform (including the SG, learning materials, lessons, questionnaires) was widely diffused in different languages (English, German, Italian, Flemish, Spanish). Pre- and post-training questionnaires were used to assess the learning experience and the efficacy of the training. Findings provided evidence supporting the learning effectiveness of ACCORD training. The experience with the e-platform has been positively rated by the users concerning both the technological and educational aspects. Overall, the study provided an overview on the creation, implementation and evaluation of a novel multicultural training tool, which has been proven to effectively foster the enhancement of intercultural and interethnic competencies of professionals working in the European educational contexts

Application of Precision Agriculture for the Sustainable Management of Fertilization in Olive Groves

Olive tree growing (Olea europaea L.) has considerably increased in the last decades, as has the consumption of extra virgin olive oil in the world. Precision agriculture is increasingly being applied in olive orchards as a new method to manage agronomic variability with the aim of providing individual plants with the right input amount, limiting waste or excess. The objective of this study was to develop a methodology on a GIS platform using GEOBIA algorithms in order to build prescription maps for variable rate (VRT) nitrogen fertilizers application in an olive orchard. The fertilization plan was determined for each tree by applying its own nitrogen balance, taking into account the variability of nitrogen in soil, leaf, production, and actual biometric and spectral conditions. Each olive tree was georeferenced using the S7-G Stonex instrument with real-time kinematic RTK positioning correction and the trunk cross section area (TCSA) was measured. Soil and leaves were sampled to study nutrient variability. Soil and plant samples were analyzed for all major physical and chemical properties. Spectral data were obtained using a multispectral camera (DJI multispectral) carried by an unmanned aerial vehicle (UAV) platform (DJI Phantom4). The biometric characteristics of the plants were extracted from the achieved normalized vegetation index (NDVI) map. The obtained prescription map can be used for variable rate fertilization with a tractor and fertilizer spreader connected via the ISOBUS system. Using the proposed methodology, the variable rate application of nitrogen fertilizer resulted in a 31% reduction in the amount to be applied in the olive orchard compared to the standard dose