Pulse vs. Optimal Stationary Fishing: The Northern Stock of Hake

Pulse fishing may be a global optimal strategy in multicohort fisheries. In this article we compare the pulse fishing solutions obtained by using global numerical methods with the analytical stationary optimal solution. This allows us to quantify the potential benefits associated with the use of periodic fishing in the Northern Stock of hake. Results show that: first, management plans based exclusively on traditional reference targets as Fmsy may drive fishery economic results far from the optimal; second, global optimal solutions would imply, in a cyclical manner, the closure of the fishery for some periods and third, second best stationary policies with stable employment only reduce optimal present value of discounted profit in a 2%.optimal fisheries, management optimization in age-structured models, pulse fishing

Benthosearcher: a machine learning based tool to ultra-fast, automatic characterization of vulnerable marine ecosystems

The degradation and impoverishment of the seabed that has been detected during last decades is the result of numerous variables, among which are uncontrolled exploitation of the seabed concerning its vulnerability, based on trawling gear. Intending to bring the situation under control, European fishing authorities have concluded a series of proposals to promote, define and defend Marine Vulnerable Ecosystems (VMEs), among which one of the most controversial and with the greatest social and economic impact is the veto of trawling in numerous fishing areas/grounds that currently are exploited by a large c number of vessels from many countries of the EU, which see their livelihood in danger. In the process of proposing an alternative that is attractive to both parts, we propose an automatic, real-time tool (BentoSearcher) based on artificial intelligence so that trawlers have will have the autonomy to decide whether or not to cast the net on the seabed in which the vessel is operating based on the data of benthic species detected in previous fishing hauls or trips that characterize and allow to identify vulnerable seabeds

Pulse vs. Optimal Stationary Fishing: The Northern Stock of Hake

Pulse fishing may be a global optimal strategy in multicohort fisheries. In this article we compare the pulse fishing solutions obtained by using global numerical methods with the analytical stationary optimal solution. This allows us to quantify the potential benefits associated with the use of periodic fishing in the Northern Stock of hake. Results show that: first, management plans based exclusively on traditional reference targets as Fmsy may drive fishery economic results far from the optimal; second, global optimal solutions would imply, in a cyclical manner, the closure of the fishery for some periods and third, second best stationary policies with stable employment only reduce optimal present value of discounted profit in a 2%.Financial aid from the Spanish Ministry of Education and Science (ECO2009-14697-C02- 01 and 02), the Basque Government (HM-2009-1-21) and the Xunta de Galicia (Anxeles Alvariño programme) is gratefully acknowledged

Caps on working hours per vessel: A general equilibrium analysis

General equilibrium analysis shows that regulation based on caps on working hours per vessel affect the entry/exit margin (more low productivity vessels stay in the fishery), wages (a less productive fleet implies lower equilibrium wages) and aggregate employment allocated to the sector. Although the total number of vessels increases, total employment in the fishery is reduced and the aggregate rents generated in the fishery are lower. Moreover, regulatory policies based on input controls also affect capital dynamics across the stock recovery phases. In comparison with a fishery regulated via efficient instruments, we find that those dynamics are characterized by fewer exits of vessels. Finally, using data from the Western Mediterranean Sea, we show that the use of input controls gives rise to a Spanish fleet around 14 percent larger than the one that would result from a non-distortionary instrument

Fleet dynamics and capital malleability

When individual stay/exit decisions depend on the opportunity cost of exiting, capital malleability is endogenously determined by the instruments used for stock rehabilitation. In a General Equilibrium framework, we characterize the transitional dynamics caused by stock rehabilitation policies. We show that a management policy based on input controls generates less exit, a less productive fleet, and overcapitalization, as input controls require a higher number of firms to achieve the same biological targets. Using data from the Multiannual Plan for the Western Mediterranean, we show that the use of input controls generates a Spanish fleet around 14 percent higher than the one that would result from a non distortionary instrument

Fleet dynamics and capital malleability

When individual stay/exit decisions depend on the opportunity cost of exiting, capital malleability is endogenously determined by the instruments used for stock rehabilitation. In a General Equilibrium framework, we characterize the transitional dynamics caused by stock rehabilitation policies. We show that a management policy based on input controls generates less exit, a less productive fleet, and overcapitalization, as input controls require a higher number of firms to achieve the same biological targets. Using data from the Multiannual Plan for the Western Mediterranean, we show that the use of input controls generates a Spanish fleet around 14 percent higher than the one that would result from a non distortionary instrument

Fleet dynamics and overcapitalization under rational expectations

When individual stay/exit decisions depend on the opportunity cost of exiting, capital malleability is endogenously determined by the instruments used for stock rehabilitation. In a General Equilibrium framework, we characterize the transitional dynamics caused by stock rehabilitation policies. We show that a management policy based on input controls generates less exit, a less productive fleet, and overcapitalization, as input controls require a higher number of firms to achieve the same biological targets. Using data from the Multiannual Plan for the Western Mediterranean, we show that the use of input controls generates a Spanish fleet around 14 percent higher than the one that would result from a non distortionary instrument

On the structure and stability of novel cationic DPPC liposomes doped with gemini surfactants

A novel formulation of cationic liposomes was studied by mixing dipalmitoylphosphatidylcholine (DPPC) with tetradecyltrimethylammonium bromide gemini surfactants with different alkane spacer groups lengths attached to their ammonium head-groups. The physicochemical characterization of the cationic liposomes was obtained by combining experimental results from differential scanning microcalorimetry (DSC) with molecular dynamic simulations, in order to understand their structural configuration. An adapted Ising model was used to interpret the results in terms of cooperativity of the phase transitions. The gemini surfactants partition into the lipid bilayer of DPPC liposomes, and the induced changes in colloidal stability and phase transition were analyzed in detail. The DPPC liposomes became positively charged upon gemini surfactant partition, showing increased colloidal stability. Our results show significant differences in structural configuration between gemini surfactants with short and long spacer lengths. While gemini with shorter spacers allocate within the lipid bilayer with both headgroups in the same layer, geminis with longer spacers unexpectedly intercalate in the lipid membrane in a particular zig-zag configuration, with each headgroup located at a different side of the bilayer, altering the coupling degree parameters of the membrane’s phase transition. The extraordinary increase of colloidal stability of DPPC liposomes with gemini surfactants at very low molar ratio and the possibility to tune the physicochemical properties of the membrane by control de spacer length of the geminis opens new possibilities for cationic liposomal formulations with potential applications in vaccines, drug/gene delivery or biosensingThis work was supported by the Spanish Research Agency (AEI) under Project PID2019-109517RB-I00. ERDF funds are also acknowledged. Facilities provided by the Galician Supercomputing Centre (CESGA) are also acknowledgedS

Advances in electronic monitoring of fishing catches based on artificial intelligence

Monitoring plays a key role in all aspects of fsheries management, including those related to sustainable management of resources, the economic performance of the fshery, and the distribution of benefts from the exploitation of the fshery and environment. In this work, software improvements made on the remote electronic monitoring (REM) device iObserver are described towards the improvement of fsheries monitoring by precisely identifying and quantifying fshing catches on board commercial vessel´s. To this aim, we exploit deep learning and convolutional neural networks (CNNs) capabilities and potential.Peer Reviewe

Characterization of Hydrogels for Their Application in Tissue Regeneration

Alterations in neurogenesis result in the inevitable loss of brain nervous tissue and cause neurodegenerative diseases, such as Parkinson’s disease (PD), Alzheimer’s disease (AD), and Huntington’s disease (HD). In this regard, hydrogels based on natural biopolymers have attractive properties, such as excellent biocompatibility, a low immune response, and a significant similarity to the extracellular matrix (ECM) of tissues, thus supporting cell proliferation and migration. Human ECM is composed by relatively small amounts of fibrous, proteins, and polysaccharides. For example, scaffolds composed of gelatin and hyaluronic acid are highly abundant components in human ECM. The methacrylation of hyaluronic acid (HAMA) and gelatin (GelMA) through carboxyl and hydroxyl groups under UV light radiation at 365 nm produce polymeric scaffolds with elastic moduli similar to tissues, and, therefore, potential candidates to adhere, host, and facilitate cell proliferation and differentiation, which are dependent on their mechanical properties. In this work, the mechanical, thermal, and morphological properties of HAMA and GelMA hydrogel mixtures were studied and characterized via linear rheological measurements, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM)S