Prevalence and characterization of Salmonella spp. in three shellfish-harvesting areas in France

Shellfish farming is an important economic activity in the Brittany and Normandy regions. However, a part of the production sites corresponds to relatively sensitive areas where the presence of faecal microorganisms is a major concern for shellfish and constitutes a possible health risk. Indeed, shellfish bioaccumulates in their tissues pathogenic contaminants present in water and can cause food-borne diseases such as salmonellosis. During a two-year study, we evaluated the presence of faecal indicators, measured the prevalence of Salmonella spp., isolated and characterized Salmonella spp. from three French shellfish-harvesting areas (shellfish and sediment) and their watersheds (from river water samples).

Energy Cooperation in Energy Harvesting Communication Systems

In energy harvesting communications, users transmit messages using energy harvested from nature. In such systems, transmission policies of the users need to be carefully designed according to the energy arrival profiles. When the energy management policies are optimized, the resulting performance of the system depends only on the energy arrival profiles. In this dissertation, we introduce and analyze the notion of energy cooperation in energy harvesting communications where users can share a portion of their harvested energy with the other users via wireless energy transfer. This energy cooperation enables us to control and optimize the energy arrivals at users to the extent possible. In the classical setting of cooperation, users help each other in the transmission of their data by exploiting the broadcast nature of wireless communications and the resulting overheard information. In contrast to the usual notion of cooperation, which is at the signal level, energy cooperation we introduce here is at the battery energy level. In a multi-user setting, energy may be abundant in one user in which case the loss incurred by transferring it to another user may be less than the gain it yields for the other user. It is this cooperation that we explore in this dissertation for several multi-user scenarios, where energy can be transferred from one user to another through a separate wireless energy transfer unit. We first consider the offline optimal energy management problem for several basic multi-user network structures with energy harvesting transmitters and one-way wireless energy transfer. In energy harvesting transmitters, energy arrivals in time impose energy causality constraints on the transmission policies of the users. In the presence of wireless energy transfer, energy causality constraints take a new form: energy can flow in time from the past to the future for each user, and from one user to the other at each time. This requires a careful joint management of energy flow in two separate dimensions, and different management policies are required depending on how users share the common wireless medium and interact over it. In this context, we analyze several basic multi-user energy harvesting network structures with wireless energy transfer. To capture the main trade-offs and insights that arise due to wireless energy transfer, we focus our attention on simple two- and three-user communication systems, such as the relay channel, multiple access channel and the two-way channel. Next, we focus on the delay minimization problem for networks. We consider a general network topology of energy harvesting and energy cooperating nodes. Each node harvests energy from nature and all nodes may share a portion of their harvested energies with neighboring nodes through energy cooperation. We consider the joint data routing and capacity assignment problem for this setting under fixed data and energy routing topologies. We determine the joint routing of energy and data in a general multi-user scenario with data and energy transfer. Next, we consider the cooperative energy harvesting diamond channel, where the source and two relays harvest energy from nature and the physical layer is modeled as a concatenation of a broadcast and a multiple access channel. Since the broadcast channel is degraded, one of the relays has the message of the other relay. Therefore, the multiple access channel is an extended multiple access channel with common data. We determine the optimum power and rate allocation policies of the users in order to maximize the end-to-end throughput of this system. Finally, we consider the two-user cooperative multiple access channel with energy harvesting users. The users cooperate at the physical layer (data cooperation) by establishing common messages through overheard signals and then cooperatively sending them. For this channel model, we investigate the effect of intermittent data arrivals to the users. We find the optimal offline transmit power and rate allocation policy that maximize the departure region. When the users can further cooperate at the battery level (energy cooperation), we find the jointly optimal offline transmit power and rate allocation policy together with the energy transfer policy that maximize the departure region.

Evolution of factors affecting mechanical olive harvesting

Harvest efficiency is defined as the percentage of fruits harvested by total production. The percentage of fruits harvested is less than 100% when working with trunk shakers to detach olives. It is important to increase the percentage of fruits harvested in order to increase farmer’s income. This objective can be achieved knowing the evolution of the main factors affecting fruit detachment. Fruit removal force (FRF), fruit weight (P) and the ratio between them are important for harvest efficiency. Field trials took place for two years (2013-2014) in Vilariça Valley, northeast Portugal in an olive orchard with ‘Cobrançosa Transmontana’ cultivar. It was adopted a mechanical harvesting system based on a trunk shaker to detach fruits, and an inverted umbrella to collect fruits. Elementary operation times were measured in seconds to evaluate work rates. FRF and P were measured in the ripening period, to evaluate their evolution. In this paper are presented the preliminary results of the ratio FRF (fruit removal force)/fruit weight evolution during the ripening period (P) and the results of the equipment work rate (trees h-1). The ratio FRF/P has predominantly descendant values in the weeks before harvest, from 140 to 80 as a result of a FRF downward variation from 4.9 to 2.94 N and an upward variation of P from 0.0294 to 0.0637 N. The FRF/P ratio stabilizes the decline in the last week of November just before harvesting, registering in some cases a slight increase in consequence of FRF increase higher than P increase (contrary to the tendency of previous weeks). Equipment work rate showed values between 40 and 57 trees h-1, confirming previous results.

Comparison between benzyladenine and metamitron as chemical thinning agents in Gala, Kanzi, Pink Lady and Red Delicious apple cultivars

Mestrado em Engenharia Agronómica - Instituto Superior de Agronomia - UL

Population structure of pond-raised Macrobrachium amazonicum with different stocking and harvesting strategies

The effect of size-grading of juveniles prior to stocking, as well as selective harvesting, on the population structure of pond-raised Macrobrachium amazonicum was studied. A randomized-complete-blocks design with 4 treatments and 3 replicates was used. The treatments were: upper size-graded juveniles, lower size-graded juveniles, ungraded juveniles (traditional), and ungraded juveniles with selective harvesting. Twelve 0.01 ha earthen ponds were stocked at 40 juveniles m(-2), according to the relevant treatment. Every three weeks, random samples from each pond were obtained for biometry, and after 3.5 months, the ponds were drained and completely harvested. Animals were then counted, weighed, and sexed; males were sorted as Translucent Claw (TC), Cinnamon Claw (CC), Green Claw 1 (GC1), and Green Claw 2 (GC2), and females as Virgin (VF), Berried (BE), and Open (OF). The prawns developed rapidly in the ponds. attaining maturity and differentiating into male morphotypes after about 2 months in all treatments. The fast-growing juveniles (upper grading fraction) mostly did not constitute the dominant males (CC] and GC2) in the adult population. Population development was slower in ponds stocked with Lower prawns, whereas selective harvesting increased the frequency of GC1 and reduced the final mean weight of GC2 males. The proportion of males increased throughout the culture period, but was generally not affected by the stocking or harvesting strategies. Grading juveniles and selective harvesting slightly altered the population dynamics and structure, although the general population development showed similar patterns in ponds stocked with upper, lower, and ungraded juveniles, or selectively harvested. (C) 2010 Elsevier B.V. All rights reserved.

Long-term assessment of wild boar harvesting and cattle removal for bovine tuberculosis control in free ranging populations

Wild boar is a recognized reservoir of bovine tuberculosis (TB) in the Mediterranean ecosystems, but information is scarce outside of hotspots in southern Spain. We describe the first high-prevalence focus of TB in a non-managed wild boar population in northern Spain and the result of eight years of TB management. Measures implemented for disease control included the control of the local wild boar population through culling and stamping out of a sympatric infected cattle herd. Post-mortem inspection for detection of tuberculosis-like lesions as well as cultures from selected head and cervical lymph nodes was done in 745 wild boar, 355 Iberian ibexes and five cattle between 2004 and 2012. The seasonal prevalence of TB reached 70% amongst adult wild boar and ten different spoligotypes and 13 MIRU-VNTR profiles were detected, although more than half of the isolates were included in the same clonal complex. Only 11% of infected boars had generalized lesions. None of the ibexes were affected, supporting their irrelevance in the epidemiology of TB. An infected cattle herd grazed the zone where 168 of the 197 infected boars were harvested. Cattle removal and wild boar culling together contributed to a decrease in TB prevalence. The need for holistic, sustained over time, intensive and adapted TB control strategies taking into account the multi-host nature of the disease is highlighted. The potential risk for tuberculosis emergence in wildlife scenarios where the risk is assumed to be low should be addressed.

Energy harvesting from hydroelectric systems for remote sensors

Hydroelectric systems are well-known for large scale power generation. However, there are virtually no studies on energy harvesting with these systems to produce tens or hundreds of milliwatts. The goal of this work was to study which design parameters from large-scale systems can be applied to small-scale systems. Two types of hydro turbines were evaluated. The first one was a Pelton turbine which is suitable for high heads and low flow rates. The second one was a propeller turbine used for low heads and high flow rates. Several turbine geometries and nozzle diameters were tested for the Pelton system. For the propeller, a three-bladed turbine was tested for different heads and draft tubes. The mechanical power provided by these turbines was measured to evaluate the range of efficiencies of these systems. A small three-phase generator was developed for coupling with the turbines in order to evaluate the generated electric power. Selected turbines were used to test battery charging with hydroelectric systems and a comparison between several efficiencies of the systems was made. Keywords

Integrated CoPtP permanent magnets for MEMS electromagnetic energy harvesting applications

This work reports the development of integrated Co rich CoPtP hard magnetic material for MEMS applications such as Electromagnetic Vibration Energy Harvesting. We report a new method of electrodeposition compared to the conventional DC plating, involving a combination of forward and reverse pulses for optimized deposition of Co rich CoPtP hard magnetic material. This results in significant improvements in the microstructure of the developed films as the pulse reverse plated films are smooth, stress free and uniform. Such improvements in the structural properties are reflected in the hard magnetic properties of the material as well. The intrinsic coercivities of the pulse reverse deposited film are more than 6 times higher for both in-plane and out-of-plane measurement directions and the squareness of the hysteresis loops also improve due to the similar reasons.

Energy harvesting for monitoring bridges over their operational life

The use of energy harvesting materials for large infrastructure is a promising and growing field. In this regard, the use of such harvesters for the purpose of structural health monitoring of bridges has been proposed in recent times as one of the feasible options since the deployment of them can remove the necessity of an external power source. This paper addresses the performance issue of such monitors over the life-cycle of a bridge as it deteriorates and the live load on the structure increases. In this regard, a Lead Zirconate Titanate (PZT) material is considered as the energy harvesting material and a comparison is carried out over the operational life of a reinforced concrete bridge. The evolution of annual average daily traffic (AADT) is taken into consideration, as is the degradation of the structure over time, due to the effects of corrosion. Evolution of such harvested energy is estimated over the life-cycle of the bridge and the sensitivity of harvested energy is investigated for varying rates of degradation and changes in AADT. The study allows for designing and understanding the potential of energy harvesters as a health monitor for bridges. This paper also illustrates how the natural growth of traffic on a bridge over time can accentuate the identification of damage, which is desirable for an ageing structure. The paper also assesses the impact and effects of deployment of harvesters in a bridge as a part of its design process, considering performance over the entire life-cycle versus a deployment at a certain age of the structure.

Capacity building activities in rain water harvesting: South Kyrgyzstan

Water and food are fundamental human rights. However, a number of communities in the world suffer due to a lack of these most basic needs. With few alternative economic opportunities, communities in rural and mountainous Kyrgyzstan have to rely mainly on agriculture for their livelihoods.

Energy harvesting from hydroelectric systems for remote sensors

Hydroelectric systems are well-known for large scale power generation. However, there are virtually no studies on energy harvesting with these systems to produce tens or hundreds of milliwatts. The goal of this work was to study which design parameters from large-scale systems can be applied to small-scale systems. Two types of hydro turbines were evaluated. The first one was a Pelton turbine which is suitable for high heads and low flow rates. The second one was a propeller turbine used for low heads and high flow rates. Several turbine geometries and nozzle diameters were tested for the Pelton system. For the propeller, a three-bladed turbine was tested for different heads and draft tubes. The mechanical power provided by these turbines was measured to evaluate the range of efficiencies of these systems. A small three-phase generator was developed for coupling with the turbines in order to evaluate the generated electric power. Selected turbines were used to test battery charging with hydroelectric systems and a comparison between several efficiencies of the systems was made. Keywords

Enzymatic activity on sediments and nematode assemblage responses during seagrass beds habitat recovery following the disturbance of the traditional digging activity of bivalves harvesting.

Sediment digging is an anthropogenic activity connected to the exploitation of living resources in estuarine and marine environments. The knowledge on the functional responses of the benthic assemblages to the physical disturbance is an important baseline to understand the ecological processes of the habitat recovery and restoration and to develop tools for the management of the harvesting activities. To investigate the effects of the digging activity of the bivalves on Zostera noltii seagrass beds a manipulative field experiment was conducted that included the enzymatic activity of sediments and the associated nematode assemblages. Four plots (two undisturbed serving as control and two dug to collect bivalves - treatment) with 18 subplots were randomly located at seagrass beds in the Mira estuary at the SW coast of Portugal. Samples were randomly and unrepeatably collected from three subplots of each plot in five different occasions, before sediment digging (T0) up to six months after disturbance (T5). Microbial activity in sediments was assess by determining the extracelular enzymatic activity of six hydrolytic enzymes (sulfatase, phosphatase, b -N-acetilglucosaminidase, b-glucosidase, urease, protease) and two oxidoreductases (phenol oxidase and peroxidase). The microbial community status was also assessed through the measurement of dehydrogenase, which reflects microbial respiration. The nematode assemblages composition, biodiversity and trophic composition at different sampling occasions were also analyzed. The fluorometric and biochemical parameters analysed of the Z. noltii plants during the experimental period showed a recovery of the seagrass beds, and it was detected an increase of the enzymatic activity of the sediments after disturbance. The nematodes assemblages were similar in all sampling occasions. The seagrass beds and the nematodes assemblages associated showed a high resilience to the stress caused by the traditional bivalves digging activity. The obtained results allow the development of a management programme for the commercial fishing activity to maintain the good environmental status and minimized the secondary environmental effects on marine and estuarine habitats through the establishment of a baseline for the regulation of the harvesting frequency.

Estudo in silico de sítios de restrição enzimática de genes da proteína capsidial e análise de diversidade genética de Apple chlorotic leaf spot virus em fruteiras de semente e caroço.

Cultivares comerciais de macieiras são infectadas por 3 espécies principais de vírus: Apple chlorotic leaf spot virus (ACLSV), Apple stem grooving virus (ASGV) e Apple stem pitting virus (ASPV), geralmente em infecções complexas. O objetivo do estudo foi caracterizar a diversidade genética de genes da proteína capsidial (CP) de isolados de ACLSV.

Advances on apple production under semiarid climate: N fertigation

The fertilizing management for apple tree is essential, especially for nitrogen, one of the most important nutrients affecting fruit yield. Thus, an experiment was conducted in 2012 and 2013 to evaluate the fruit production, yield and leaf chlorophyll of ?Princesa? and ?Eva? apples as a function of nitrogen fertigation under Brazilian semiarid conditions. The experimental design consisted of randomised blocks, with treatments distributed in a factorial arrangement 2 x 4, corresponding to apple cultivars (Eva and Princesa); and nitrogen doses (160, 120, 80 and 40 kg of N ha-1), with four replications and three plants. Calcium nitrate was used as nitrogen source (15.5% of N) with applications twice a week during 40 days, reaching 12 fertilizing performances through irrigation water. The following variables were evaluated: i) fruit production per plant (kg plant-1); ii) fruit yield (t ha-1); iii) number of fruits per plant; iv) leaf chlorophyll meter readings (index); and v) leaf nitrogen concentration (g kg-1). Princesa apple cultivar if compared to ?Eva? presents a better fruit production performance under Brazilian semiarid. Furthermore, nitrogen doses fertilized through irrigation water have no effect on fruit production of Eva and Princesa apple cultivars during the first production cycle.

Integrated control of two tortricid (Lepidoptera) pests in apple orchards with sex pheromones and insecticides.

The apple is attacked by a significant number of insect pests in Brazilian commercial orchards, including Bonagota salubricola and Grapholita molesta (Lepidoptera: Tortricidae). Sexual disruption of B. salubricola and G. molesta was evaluated in apple orchard using the flowable pheromone formulations, SPLAT Grafo+Bona (SG+B), SPLAT Attract and Kill Grafo+Bona (SAKG+B), and compared with the standard insecticides used for management in the Integrated Apple Production (IAP) system. Both formulations were applied at a rate of 1kg/ha on October 10, 2005 and December 13, 2005 using 300 and 1000 point sources/ha of SG+B and SAKG+B, respectively in experimental units of 7 ha. Adult male captures of B. salubricola and G. molesta were evaluated weekly in Delta traps with specific synthetic sex pheromone from October 10, 2005 to February 14, 2006. Damage to fruits was evaluated on November 21 and December 21, 2005, and January 25 and February 14, 2006. In the SPLAT treated experimental units a significant reduction was observed in the number of B. salubricola and G. molesta males caught in Delta traps compared to the experimental unit IAP. Damage by B. salubricola at harvest ranged from 1.63 to 4.75% with no differences between treatments, while damage by G. molesta was near zero in all experimental units. Mating disruption using SG+B and SAKG+B was sufficient to control B. salubricola and G. molesta with results equivalent to IAP guidelines. This technology is promising for management of both pests in Brazilian apple orchards with immediate reduction of 43% in the number of insecticide applications.