Top PDF Nutrition and quality of aquaponic systems

Increasing world population and food demand have in recent years raised concerns about agroecosystems sustainability. While it is not certain if past trends in agriculture productivity can continue with the same pace, there is a raising awareness that food production should look into system integration. Aquaculture is seen as one of the solutions available, since fish can be more productive than warm blooded animals. Nevertheless integration of aquaculture wastes with agriculture can reduce sensitively the use of production inputs. In the case of aquaponics, the soilless plant production (hydroponics) on aquaculture water, there is a symbiotic association between fish and plants. Wastes from animals are nutrients for plants, which grow with no use of additional fertilization and serve to reclaim water into the system. Given optimal fish/plant ratio the system could be as performing as high-input agriculture. Two consecutive aquaponics trials with sweet basil (Ocimum basilicum L. cv superbo) and African catfish (Clarias gariepinus B.) were carried out at the experimental farm of the university of Tuscia in summer 2010. Two treatments, consisting of fish feeding a low protein (LP) and high protein diet (HP) under same stocking densities, supplied nutrients to sweet basil plants growing on floating rafts. Vegetable production was compared against a standard hydroponic control. No significant differences were noticed between aquaponics and hydroponics for both production and quality of plants, however vegetables differed in mineral composition, following the nutrient patterns present in water. Likewise catfish growth and feed conversion rate was similar in both diets. A nutrient budget was developed to determine nutrient uptake efficiency and to optimize fish/plant ratio. For the first trial uptake efficiency for both nitrogen, phosphorus and potassium was similar in all treatments, however in the second trial the increased fish biomass and the consequent increases in nutrient wastes lowered plant uptake efficiency in aquaponics. The optimal feed/plant ratio resulted in 27.2 g feed plant -1 (LP) and 18.8 g feed plant -1 (HP).

In Italy from the beginning of XX th Century were realized widespread reforestations, these activities continued up to the Second World War. Most of the barren areas were planted with conifers, considered more appropriate in poor soil conditions. So in unfavourable soil conditions the tree selection was addressed to the pines species, which are particularly tolerant, in particular Pinus nigra was the most omnipresent species. In warmer climate conditions were planted Mediterranean pines, particularly Pinus halepensis and Pinus pinaster. Nowadays most of the pine reforestations are in difficult stand situations, with excessive density, so starting intra-specific competition, producing trees particularly vulnerable to various stress factors and especially to aridity. Therefore it is essential to carry out thinning, with different features, appropriate to stands conditions and management strategies. Ideally thinning should be of moderate intensity, so that residual trees will not be stressed and frequent in short time intervals to stimulate tree growth (Ciancio 1986). Unfortunately selective thinning with a low removal intensity involves high costs, so often these treatments must be intensified to obtain a net income. Accordingly in low quality stands it is more advisable a geometric thinning, opening corridors and allowing machines passages, but also this solution rarely allows complete economic sustainability in energy wood harvesting (Magagnotti et al. 2009).

an aromatic cation (e.g. N-butylpyrimidinium or 1-ethyl-3-methylimidazole) and an inorganic anion (e.g. chloraluminate). It is evident that these compounds, although not very volatile, presented toxicity problems, especially about the aromatic cation. The ionic liquids subsequently studied were those having non-aromatic organic cations (e.g. Butylammonium + 3,4-dihydroxycinnamate). These compounds, defined as "second generation", had a limited diffusion despite their reduced toxicity, because only a few of the hundreds synthesized were liquids at room temperature [60]. Starting from the ionic liquids obtained, other systems were sought to make them compatible with the roles for which they were intended. Thus, task-specific ionic liquids (TSIL) were prepared in which the cation of a second generation ionic liquid was modified with different functional groups, thus giving new properties to the resulting compound. Many of these functionalized ionic liquids, defined as "third generation", were solid or extremely viscous at room temperature. This problem was partially worked out by solubilizing them in the non-functionalized ionic liquid, thus creating "task-specific" binary ionic liquids (BTSILs) [61].

• the equations defining the control solutions are generally highly nonlinear. After a transient silent period lasted almost twenty years, sampled-data systems have found a renewed interest by the control community throughout the last few decades motivated by the current technological developments. As a consequence, the aforementioned issues and questions have been re-addressed by several researchers in the field. Accordingly, an extended body of methodologies has been developed for sampled-data control so that the following rough classification can be deduced depending on the entry point one adopts for the definition of the control feedback. Emulation-based design – The design is carried out over the continuous-time original system by neglecting the effect of sampling so that the overall feedback is directly implemented through Zero-Order-Hold (ZOH) devices. Such an approach is rather naive and requires no extra design effort though it does not keep into account the effect of sampling (both in the measures and the input signal) over the closed-loop system. Accordingly, the same performances as in the continuous- time case are not preserved as the sampling period increases so preventing from fulfilling the control specifications the ideal continuous-time feedback was design to satisfy. Several works are aimed at quantifying estimates of the sampling period preserving the performances of the continuous-time systems and, thus, the quality of emulation-based feedbacks as in the works by Carnevale, Hetel, Mazenc, Nesic Omran and many others (e.g., [ 143 , 110 , 147 , 146 , 157 ]) even in the case of aperiodic sampling.

In all EU countries where capitation payments account for an important part of the funding given to general practitioners – i.e. Denmark, Ireland (where lower income groups are concerned), Italy, the Netherlands and the UK – everyone has to register with a particular general practitioner, group of general practitioners or health centre. Portugal, Spain and Slovenia also run patient list systems. In principle the patient list system is not directly linked to the gatekeeping role. Gatekeeping can be found in countries where patients are not registered with a primary care practice, such as Iceland, Croatia and, until introduction of the patient list system in June 2001, Norway. Within the European Union, however, patient list systems are always found in conjunction with gatekeeping arrangements: all EU countries either have both or have neither. Though there are no comparative international data on this issue, it seems quite plausible that registration with primary care facilities strongly contributes to the realisation of continuity and coordination in the delivery of healthcare. With respect to this last aspect, a system in which patients are registered with a GP offers a greater likelihood that medical information is stored in one place, than do systems without patient lists. A patient list system is not sufficient, however. Individual GPs need to keep comprehensive medical records and keep good working relationships with other health professionals in primary and secondary care. Computerized medical records are not just helpful for coordination and in providing continuous care to individual patients. A good practice database is also essential for the systematic screening and follow-up of patients affected by chronic ills. Routinely kept medical records become a major source of information for both epidemiological and health services research (Rosser and Van Weel, 2004; see also chapter I and III in this thesis). In some countries, the patient list system also applies to pharmacies. Registration of patients in one pharmacy greatly facilitates an active role of pharmacists in primary care, such as monitoring the medication of individual patients.

3 typically contains quite a lot of redundancy. This is partly due to the fact that computing cores is a challenging task. A possible approach to the generation of core solutions for a relational data exchange problem is to generate a canonical solution by chasing the tgds, and then to apply a post-processing algorithm for core identification. Several polynomial algorithms have been identified to this end [43, 51]. These algorithms provide a very general solution to the problem of computing core solutions for a data exchange setting. Also, an implemen- tation of the core-computation algorithm in [51] has been developed [74], thus making a significant step towards the goal of integrating core computations in schema mapping systems. However, experience with these algorithms shows that, although polynomial, they require very high computing times since they look for all possible endomorphisms among tuples in the canonical solution. As a consequence, they hardly scale to large mapping scenarios: even for databases of a few thousand tuples computing the core may require several hours.

ˆ DP-VW: it is a combination of truncated DP approaches and variable window methods; in this case, UC planning time window size is variated according to the increment of load demand reducing running times and obtaining a solution of acceptable quality [OS91]. The solution obtained by the DP approaches mentioned above is suboptimal, in particular when large-scale systems are considered, since these algorithms are based on priority lists or truncated combination methods. When the UC problem is decomposed into smaller sub problems which are solved by these DP approaches, Successive Approximation methods (SA) and Hierarchical approaches methods (HA) can be used in order to coordinate these sub problems, respectively either sequentially or in parallel [BH85] [HB86]. In order to reduce the solution space Lagrangian reduction can be combined with SA approaches considering the dual nature of the UC [NaIG87]. Recent trends on methods to solve the UC have been focused attention on the integration of fuzzy logic, expert systems and neural networks into DP approaches. Fuzzy logic can be applied to DP when load demands and generation parameters are known with uncertainty [SH91]. Nevertheless, the fuzzy approach requires a larger computational effort than the conventional DP method. The utilization of expert systems has been taken into account too, in order to enhance DP approaches, especially when truncated DP methods are developed. Constraints that are difficult to implement in a DP algorithm for the UC can be easily managed by this expert system [MSW88] [SHN91]. Neural networks have been integrated into DP algorithm too to generate economic dispatch schedules and the whole UC solution [KP07].

It is now clear that one of driving forces causing changes in the environment at local, regional, and even global scales is the human activity. Social, economic, and cultural systems are changing in a world that is more populated, urban, and interconnected than ever. Available statistics show that more than half (51%) of the world’s 7 billion people live in urban areas, value rising to 68% in Italy (Population Reference Bureau, 2012). Main effect of the urbanisation process is certainly the increasing use of virgin lands destined for urban use, making them ever more impervious (Paoletti, 1997; Cannata, 1993). The growth and spread of impervious surfaces within urbanizing watersheds pose significant threats to the quality of natural and built environments. These threats include increased stormwater runoff, reduced water quality, higher maximum summer temperatures, degraded and destroyed aquatic and terrestrial habitats, and the diminished aesthetic appeal of streams and landscapes (Barnes et al., 2002). Impervious surfaces like roads, parking lots, rooftops and sidewalks are made of asphalt, concrete or stones, and their presence change water cycle in urban areas (Fig. 1. 6). When landscapes are natural, the falling rain can easily infiltrate to the soil or be absorbed by vegetation. The latter also slow down the surface runoff, increasing watershed time of concentration. Moreover water infiltrated into soil is naturally filtered of impurities before it supplies groundwater or it reaches lakes, streams, rivers and sea. Conversely when a site is developed, it becomes less permeable and therefore less water can infiltrate back into the ground. As a consequence, rainfall is converted quickly into storm water runoff that can lead to increasing flooding events in our cities. Other negative effects of imperviousness are:

69 possible future strategy to offset fossil fuels for energy production. In fact, biomasses can represent a valid source of green energy in the next decades being fermentable sugars a valid substrate for bioethanol production and for the production of chemicals via fermentation. It is conceivable to argue that the production of biofuels can fuel the debate about food security and sustainability along with ethical concern regarding the possibility of competition for food production, increase of deforestation and other kind of land degradation (120). Because of that, competition for land use destination may arise. For example, recent investments in biofuel in United States have reduce the overall importation of oil from abroad but such strategy has also reduced supplies of food and grains with arguable reduction in the greenhouse emission (121). It has been estimated that we are currently exploiting half of the usable land in the world for agricultural and pastoral activities (122), further cultivation for biomass production would in turn determine a change in the land use destination of either marginal areas or woody lands with unavoidable soil degradation. Regardless the increasing demand for new lands that would come into being if humankind is to rely on biomass energy in the next future, 70 million ha are due to be subtracted to natural ecosystems in developing countries in order to meet the increasing demand for food by 2050 (6). Increasing the quality of the biomass can make production systems more efficient and hence reduce the need of land for biomass production. However, it is conceivable that agricultural biomass production for industry in the future would be devoted to the production of high value compounds as nutraceuticals and pharmaceutical preparations, and that low value biofuels would be mainly produced by recycling waste biomass.

unequivocal identity of the analyte when used with conventional detection systems. Uncertainty may arise because another component of the mixture may elute at the desired retention time. A compound-specific detector is thus an essential adjunct to characterize unambiguously the components that elute from any separation system. In this respect, mass spectrometry offers the unique advantages of high molecular specificity, detection sensitivity and dynamic range. Only mass spectrometry has the ability to provide confirmatory evidence of an analyte because of its ability to distinguish closely related compounds on the basis of the molecular mass and structure-specific fragment ion information. The confidence in identification of a target compound, however, diminishes when it is present in a mixture. Because of the universal nature of mass spectrometry detection, the data obtained might also contain signal due to other components of the mixture. The coupling of a separation device with mass spectrometry thus benefits mutually. The result is a powerful two-dimensional analysis approach, where the high- resolution separation and the highly sensitive and structure-specific detection are both realized simultaneously. Following are some of the benefits that accrue when a separation technique and mass spectrometry are coupled.

Flavonoids are polyphenolic compounds comprising fifteen carbons, with two aromatic rings (rings A and B in Figure 1.3) connected by a three-carbon chain that forms a closed pyran ring (heterocyclic ring containing oxygen, the C ring) with ring A. Therefore, their structure is also referred to as C6-C3-C6. They can be subdivided into different subgroups depending on the carbon of the C ring on which B ring is attached, and the degree of unsaturation and oxidation of the C ring. Flavonoids in which B ring is linked in position 3 of the ring C are called isoflavones; those in which B ring is linked in position 4, neoflavonoids, while those in which the B ring is linked in position 2 can be further subdivided into several subgroups on the basis of the structural features of the C ring. These subgroup are: flavones, flavonols, flavanones, flavanonols, flavanols or catechins and anthocyanins. Finally, flavonoids with open C ring are called chalcones. In each subgroup flavonoids can be differentiated based on the substituents on rings A and B [21]. Hydroxyl groups are usually present at the 4, 5 and 7 positions. Sugars are very common with the majority of flavonoids existing naturally as glycosides. Whereas both sugars and hydroxyl groups increase the water solubility of flavonoids, other substituents, such as methyl groups, make flavonoids lipophilic. Their biological activities depend on the structural features of the ring B and the patterns of glycosylation and hydroxylation of the three rings, making the flavonoids one of the most diversified groups of phytochemicals [22]. Although flavonoids are ubiquitous in higher plants, their substitution with specific groups may be peculiar to certain species.

All experiments were conducted at the same mean temperature (15°C), relative humidity (74%) and CO2 concentration (400 µmol mol -1 ). The mean daily photosynthetic active radiation (PAR) was 5.0 (low, Exp. I), 6.8 (medium, Exp. II) and 9.0 (high, Exp. III) mol m -2 . For each trial seeds of Brassicia juncea L. cultivar Red Giant and Brassica rapa L. subsp. nipposinica var. chiloneifera. cultivar Mibuna Early were sown in rockwool cubes under greenhouse conditions. The plants at the two-true leaf stage, 25 days after sowing, were transferred into eight meter long gullies supplied continuously with nutrient solution. Distance between the 46 plants in each gully amounted to 0.17 m. Total nitrogen concentration was the same in all treatments but treatments differed in nitrogen forms (100 % NH4, 50% NH4 + 50 % NO3, 100 % NO3). In 100% NH4 treatment, NH4 was supplied using NH4Cl while NH4NO3 was used in the 50% NH4 + 50 % NO3 treatments. Treatments were arranged in a randomized complete block design with three replications. Macronutrients were supplied in all treatments at the following concentrations (mM): K 3.6, Ca 4.2, P 0.6, Mg 1.0, S 1.3; micronutrients had the following concentrations (µM): Fe 40.0, Mn 5.0, Zn 4.0, B 30, Cu 0.5, Mo 0.5. During all experiments, the electrical conductivity was kept at 2 dS m -1 by adding stock solution or deionised water according to the variations (± 10% of the target value). In all nutrient solutions a MES buffer was applied at 1.5 mM to keep the pH in the range of 5.6-5.8. Moreover, phosphoric acid or potassium hydroxide was added when the solution pH drifted above or below the threshold.

The electrical system should not only be able to provide cheap, safe and secure energy to the consumer, but also to compensate for the continually changing load demand. During that process the quality of power could be distorted by faults on the system, or by the switching of heavy loads within the customers facilities. In the early days of power systems, distortion did not impose severe problems towards end-users or utilities. Engineers first raised the issue in the late 1980s when they discovered that the majority of total equipment interruptions were due to power quality disturbances. Highly interconnected transmission and distribution lines have highlighted the previously small issues in power quality due to the wide propagation of power quality disturbances in the system. The reliability of power systems has improved due to the growth of interconnections between utilities. In the modern industrial world, many electronic and electrical control devices are part of automated processes in order to increase energy efficiency and productivity. However, these control devices are characterized by extreme sensitivity in power quality variations, which has led to growing concern over the quality of the power supplied to the customer.

and high-performance columns that provide minimum broadening of the separated bands are the heart of the modern LC system. Besides the nature of the packing material, an important role is played by the way how the columns are packed. They need also to be appropriately designed in order to minimize the dispersion and to allow the individual solutes to reach the detector, after they have been moved apart and separated. After injection into an HPLC column, any sample components that doe not interact with the stationary phase would be eluted in the void volume (vo) which is characteristic for that column. This void volume represents both the interstitial volume between the particles of the bonded phase and the available volume within the particle pores themselves. The retention times, tr(A) and tr(B), for the two sample components shown in Figure 1.1.2 are the times elapsed from injection to the times of maximum concentration in the eluted peaks. Similarly, the retention volumes are the amounts of solvent required for their elution. The basic principle of this separation techniques derive from various parameters that are summarized here:

Replication of content is an important issue in P2P systems, especially if these are de- voted to collaborative knowledge management [ 26, 28, 31, 66]. Replication mecha- nisms are usually classified into reactive and proactive mechanisms [ 140]. In reactive replication, as objects are transferred from the home node to the requesting peer, in- termediate nodes through which the data flows, determine independently whether or not to cache the content. Some researchers propose to cache pointers instead of real objects in order to yield better query search performance. In DiCAS [ 175], queries are forwarded to peers of a predefined group which passively cache the pointers in an unstructured P2P network. However, a large overhead is necessary to update the pointers when the object is moved or deleted, since the updated location information has to be flooded to the whole overlay network. In proactive replication, content is pushed to selected peers by the node that stores the primary copy, in order to obtain better performance in terms of query latency, load balance etc. However, the cost of replicating objects to a large number of peers can be cumbersome in both terms of disk space and bandwidth, particularly for systems that support applications with large objects (e.g., audio, video, software distribution). A replication strategy based on object popularity in unstructured P2P networks is explored in [ 31]. Nevertheless, this strategy does not reduce the worst-case search latency for all the objects. The strategy adopted in this paper borrows characteristics of both reactive and proac- tive approaches. A push-based mechanism is initiated by a peer when it generates or receives an updated version of an object, since it forwards this object to other workers, in a P2P fashion. This approach assures a quick dissemination of objects to the members of a community but, owing to its decentralized and unstructured na- ture, cannot guarantee that every worker is given the updated version of every shared object all the time. However, the updated version of an object is always maintained by the related Manager node. Therefore, whenever a worker cannot obtain the up- dated version of an object through the P2P mechanism, it can always request this object, with a pull modality, to the Manager. An issue strictly related to replica- tion is content consistency, which is, in fact, a fundamental reliability requirement

It is worth noting that the proposed NNE model estimates the dynamic contribution taking only the current I in as input. In fact, the internal state re- lated to V dyn is modeled by means of the feedback loops of the Leaky-RNN. Conversely, the black box models ELM, RBF-NN, and WNN need to include the previous sample of the output voltage V out [ k − 1 ] in the input tuple for ap- proximating V out [ k ] . However, due to the very slow dynamics characterizing the cells (hundreds or even thousands of seconds) and because the sampling time is usually set close to one second, black box models can easily converge to the trivial prediction model in which V out [ k ] ' V out [ k − 1 ] . This fact could jeopardize the effectiveness of the models in the SoC estimation task since it widely compromises the dependence of V out on SoC. Indeed, as any state ob- server, SR-UKF requires that all the state variables must affect the output of the model in order to allow their effective estimation. If the model converges to V out [ k ] ' V out [ k − 1 ] , the influence of SoC in the estimation of V out is re- duced or even nullified, compromising its estimation. The proposed neural model overcomes the drawback discussed above. In fact, it avoids the in- troduction of a sliding windowing of V out , preserving the influence of SoC in the model output. In addition, it has the further advantage of estimating sep- arately the unknown distinct voltage responses, providing then information about the physical behavior of electrochemical cells.

Chitosan oligosaccharides (COS) are obtained through chemical or enzymatic hydrolysis from chitosan and their use has recently increased. Unlike chitosan, COS are soluble in aqueous solutions in all proportions, due to the short chain length and to the free amino groups in D-glucosamine units (Jeon et al. 2000). Moreover, they are biodegradable, biocompatible, atoxic and have a low viscosity. These characteristics attracted researchers’ attention for being promising oligosaccharides that have potentials in agriculture and in cosmetic, pharmaceutical and food industry. Several biological activities of COS have been demonstrated in recent years, including antimicrobial (Jeon and Kim 2000 and literature cited therein; Jeon et al. 2001; Choi et al. 2001), antitumoral (Nam et al. 1999; Jeon and Kim 2002; Nam et al. 2007; Shen et al. 2009), antioxidant (Xing et al. 2005), hypocholesterolemic (Kim et al. 2005), hypoglycemic (Miura et al. 1995), anti-Alzheimer's (Yoon et al. 2009) and accelerating calcium absorption (Jung et al. 2006). Moreover, COS have proven to promote plant growth, improving the capacity of plants against salt and drought stress (Dzung et al. 2011; Chatelain et al. 2014; Zou et al. 2015) and to be effective elicitors of innate immunity against diseases of plants such as tobacco, rice, grape and other (Agrawal et al. 2002; Eikemo et al. 2003; Cabrera et al. 2006; Chen et al. 2009). Studies on their use as biopesticides have been conducted, indeed they have a powerful protective effect on various species of plants of economic interest (Yin et al. 2010; Zhao et al 2007). They are an effective post-harvest treatment for inhibiting diseases, which affect many fruits such as citrus fruits, tomato, pear, apple and peach (Chien et al. 2007; Badawy and Rebea 2009; Meng et al 2010; Yang et al 2010, 2012; Yan et al. 2011). It was also demonstrated that a pre-harvest administration of COS determines a higher post-harvest resistance to pathogens (Yan et al. 2012; Ma et al. 2013). Their biological activity strictly depends on its chemical and physical properties such as viscosity, polymerization degree and deacetylation degree (Cabrera et al. 2006 and literature cited therein; Zou et al. 2015).

We propose a novel protocol for WSNs that performs decentralized time- synchronized channel swapping (DT-SCS) and circumvents certain conver- gence and network utilization problems of existing designs, such as the state- of-the-art TSCH protocol of IEEE802.15.4e-2012. The unique aspect of our approach is the use of pulsed coupled oscillators that concurrently perform synchronization and desynchronization in multiple channels. This allows for rapid convergence to the steady state in a completely decentralized manner, that is, without requiring a node or channel coordinator, or time synchroniza- tion via a global clock. DT-SCS spontaneously adapts to node churn and vary- ing packet losses, while offering high degree of connectivity through channel swapping. Experimentation via simulations and a real Contiki-based imple- mentation on TelosB motes shows that, in comparison to TSCH, the proposed DT-SCS leads to a significant reduction of the convergence time and substan- tially higher network throughput utilization. These traits render the proposed DT-SCS an excellent candidate for WSN deployments that collect and com- municate large quantities of information in a decentralized manner.

In a scenario of rapid growing small UAS applications, the UTM system is envisioned to enable safe and efficient operations, by providing services such as airspace design, corridors, dynamic geofencing, severe weather and wind avoidance, congestion management, terrain avoidance, route planning and re-routing, separation management, sequencing and spacing, and contingency management (Ren et al. 2017). The most significant benefit of the UTM system is that it would not rely on as many technologies as concepts that require the UAS itself to equip fully for safe operation in the existing airspace. Standing on current guidelines, UTM will adopt the principle of distributed authority rather than relying on centralized control (Kopardekar et al. 2016). This opens up the system to more service providers. Decentralization privatizes the cost of serving and adapting to market needs, while government regulators remain key for ensuring that safety, access, and equity are maintained (Airbus 2018).

Culture medium was discarded and cells were washed twice in PBS at 37°C to preserve their viability, and then detached from flask by standard trypsinization. 10 6 cells per sample cells were washed twice in PBS/glucose 90 mg/100 mol at 37°C. Cells were then suspended in 1 ml PBS-glucose 90 mg/ml containing 10 μM dichlorofluorescein 2’-7’-diacetate (DCFH- DA) (Sigma-Aldrich). Samples were incubated for 30 min in the dark, to allow the probe uptake. Cells were washed twice with PBS/glucose buffer and recovered for 60 min in the dark before analysis. DCFH-DA diffusion into cells was allowed by acetyl groups, while deacetylation by intracellular esterase activity prevented the DCFH exit from cells (Gnocchi et al., 2012). Emission analyses were performed immediately after treatment by the automatic plate reader Victor 3V Perkin Elmer and Wallac 1420 software. Excitation and emission wavelengths were set at 498 nm and 530 nm. Samples fluorescence was reported in arbitrary units (UAF). To assess ROS content variations after X-ray exposure, cells were irradiated during the terminal recovery time. The assay was repeated five times.