Search results for "Fish"
showing 10 items of 3164 documents
Improved growth performance in rainbow trout Oncorhynchus mykiss reared at high densities is linked to increased energy retention
2015
Abstract Behaviour has been suggested as an underlying factor influencing how rearing density affects growth performance in Salmonid fishes. At low densities there is an elevated intensity of aggressive interactions and the formation of dominance hierarchies. As density increases, it is commonly assumed that aggression decreases, as the cost and effort required to establish and maintain dominance hierarchies increase. The increased energy expenditure associated with aggressive interactions has been identified as one mechanism causing a reduced efficiency in feed utilisation and therefore decreased growth performance. Manipulating aggressive behaviour through density may have advantages from…
Identifying causes, dynamics and consequences of work accidents in forest operations in an alpine context
2016
Abstract In a sustainable perspective, where wood harvesting and use perfectly respond to environmental needs, social sustainability and related health and safety of forest workers cannot be disregarded. The aim of this study was the analysis of the accidents records in public companies in the Province of Trento, in Northern Italy, regarding forest operations in the period 1995–2013. Several information were available thanks to the up-to-date accident books compiled by each company. With an average Frequency index in the examined period of 88 injuries per million hours worked, forest operations were confirmed as one of the most dangerous works along all productive sectors. Monday had a sign…
First results of iButton® loggers and infrared camera application inside a greenhouse
2017
Greenhouse microclimate management (temperature, relative humidity) plays a very important role in order to optimize the production process improving pest and disease control, irrigation and energy efficiency. The systems mostly used in Sicily (south Italy) to record the ambient parameters are made up of fixed measuring stations able to give useful information about the climate inside the greenhouse limited to some pre-fixed points. In this study we texted a novel system made up of humidity and temperature data loggers (iButton®) placed inside a greenhouse. The iButton® temperature/humidity logger (DS1923) is a rugged, self-sufficient system that measures temperature and/or humidity and r…
The identifiability analysis for setting up measuring campaigns in integrated water quality modelling.
2012
Abstract Identifiability analysis enables the quantification of the number of model parameters that can be assessed by calibration with respect to a data set. Such a methodology is based on the appraisal of sensitivity coefficients of the model parameters by means of Monte Carlo runs. By employing the Fisher Information Matrix, the methodology enables one to gain insights with respect to the number of model parameters that can be reliably assessed. The paper presents a study where identifiability analysis is used as a tool for setting up measuring campaigns for integrated water quality modelling. Particularly, by means of the identifiability analysis, the information about the location and …
Discussion of “Analysis of Geometrical Relationships and Friction Losses in Small-Diameter Lay-Flat Polyethylene Pipes” by Giuseppe Provenzano, Vince…
2016
For a lay-flat drip line with an inner nominal diameter dn = 16 mm, characterized by three different pipe wall thicknesses, WT, 6, 8 and 10 mil, the Authors of the original paper very accurately investigated the geometrical expansion of the cross-sectional diameter as a function of different pressure head values, ranging in between 0.84-17.55 m. Results obtained by the Authors, for pressure heads not exceeding a threshold pressure value, showed significant d variations, in a very narrow range of pressure heads, which however is seldom considered in practice (less than 3 m). The Authors experimentally evaluated a modified Blasius’ law friction coefficient, c, equal to 0.285, corresponding to…
Describing urban soils through a faceted system ensures more informed decision-making
2016
Urban areas are increasing worldwide at a dramatic rate and their soils definitely deserve more attention than they have received in the past. In urban environments, soils potentially provide the same ecosystem services as in rural and wild environments, although in some cases they are depleted of their basic functions, such as when they lose their productive and filtering capacities because of sealing, and become mere supports for infrastructures. In other cases, soils of urban areas acquire new functions that are unique to these environments. Current soil classifications fail to effectively account for the complexity of urban soils and the information that is required for their management…
New theoretical solution of the outflow process with a weir with complex shape
2016
AbstractIn this paper, the outflow process of a weir with an irregular shape is studied using dimensional analysis and the incomplete self-similarity theory. The new unique stage–discharge relationship, which is deduced theoretically, represents a novel and comprehensive equation to describe the weir outflow process for a full range of flow and different geometric variables of weirs, including finite-crested weirs, broad-crested weirs with positive or negative crest slope, broad-crested weirs with an upstream, downstream, or both upstream and downstream crest ramps, and, triangular weirs with an upstream or downstream ramp. Finally the proposed stage–discharge relationship is calibrated usi…
Inferring Population Structure from Early Life Stage: The Case of the European Anchovy in the Sicilian and Maltese Shelves
2022
The European anchovy is an important fishing resource in the Sicilian Channel that supports a high recruitment success variability. The presence of two spawning areas, the drifting of the larvae along the currents and the different oceanographic conditions within the region suggest the presence of different larvae subpopulations. Morphometric and biochemical approaches have been used to analyze the differences among larvae collected. The amino acid composition discriminates two larval groups closely related to the spawning regions: Adventure Bank and the shelf between the South of Sicily and Malta. In addition, there are morphometric and growth differences between recently hatched larvae in…
Mean flow, secondary currents and bed shear stress at a 180-degree laboratory bend with and without enhanced permeable groins as an Eco-friendly rive…
2022
River restoration aims to apply environmentally-friendly structures for bank protection in meandering rivers to restore their natural habitat. Enhanced Permeable Groin (EPG) is a novel river restoration technique that can improve the fish habitat environment in a river system by creating a series of eco-friendly scour pools. This study reports the results of two groups of 3D velocity measurements in a 180-degree channel bend in cases with and without an EPG for clear water conditions to characterize the mechanisms leading to the primary stages of the scouring phenomenon. The analysis revealed that the presence of an EPG amplified the velocity magnitude in the regions near the tip of the van…
Prospective, randomized, single-center trial comparing double-balloon enteroscopy and spiral enteroscopy in patients with suspected small-bowel disor…
2013
Background Double-balloon enteroscopy (DBE) is an established method in diagnostic and therapeutic small-bowel enteroscopy. Objective Spiral enteroscopy (SE) appears to be a promising new technique. A randomized, prospective study was conducted to compare both methods. Design Randomized, prospective study. Setting Single tertiary referral center. Patients Between September 2009 and March 2011, 26 patients with suspected mid-GI disorders completed the study. Interventions Patients were randomly assigned to DBE or SE. The oral examination was conducted first, with the deepest point reached being marked with India ink. An additional anal examination followed the day after, with the aim of reac…