The Collapse of a Wedge Clam Fishery in the Spanish Mediterranean Coast and Recovery Problems

[EN] In the sandy shores of the Spanish Mediterranean, Donax trunculus (Linnaeus, 1758) has a high commercial interest. In the Gulf of Valencia, poor management of fishing activity led to its closure in June 2015. The objective of this study was to analyze the evolution of the catches of D. trunculus before the closure of the fishery as well as the biomass and density of the population in the months following the closure, plus 2 y later. The area of study was located in the main fishing area of the Gulf of Valencia, which belongs to the fleet of the Gandia Fishermen's Guild. The fishing beds for this clam are found on sandy sediments in shallow waters (between 0 and 2 m). During the 10 y previous to the fishery closure, the annual catch per unit effort of D. trunculus suffered a sharp decrease, falling from values between 37 and 42 (kg small vessel(-1) d(-1)) during the period 2004-2008 to 5.5 in 2014. After the closure, the biomass and density of the wedge clam showed a seasonal pattern, with maximum values in summer, as well as notable differences in densities along the shore in each sampled month. Furthermore, a different size-frequency distribution across depth, with smaller individuals in the shallower areas, was observed. Nevertheless, a general and considerable decline for biomass and density from 2015 (monthly mean of commercial biomass ranged from 24 to 48 kg ha(-1)) to 2017 (from 4 to 13 kg ha-1) was noted. This indicates that the closure did not improve the state of the population. There are several hypotheses that could explain this decline such as overfishing, changes in environmental conditions, higher predation (in benthic and planktonic phases), and the reduction of food availability. Therefore, there would be a need to study them in greater depth, as well as to increase the understanding of the spatial dynamics and connectivity of the Donax beds.Escriva, J.; Rodilla, M.; Llario, F.; Falco, S. (2021). The Collapse of a Wedge Clam Fishery in the Spanish Mediterranean Coast and Recovery Problems. Journal of Shellfish Research. 40(1):37-47. https://doi.org/10.2983/035.040.0105S374740

Energy use for urban water management by utilities and Households in Los Angeles

Reducing energy consumption for urban water management may yield economic and environmental benefits. Few studies provide comprehensive assessments of energy needs for urban water sectors that include both utility operations and household use. Here, we evaluate the energy needs for urban water management in metropolitan Los Angeles (LA) County. Using planning scenarios that include both water conservation and alternative supply options, we estimate energy requirements of water imports, groundwater pumping, distribution in pipes, water and wastewater treatment, and residential water heating across more than one hundred regional water agencies covering over 9 million people. Results show that combining water conservation with alternative local supplies such as stormwater capture and water reuse (nonpotable or indirect potable) can reduce the energy consumption and intensity of water management in LA. Further advanced water treatment for direct potable reuse could increase energy needs. In aggregate, water heating represents a major source of regional energy consumption. The heating factor associated with grid-supplied electricity drives the relative contribution of energy-for-water by utilities and households. For most scenarios of grid operations, energy for household water heating significantly outweighs utility energy consumption. The study demonstrates how publicly available and detailed data for energy and water use supports sustainability planning. The method is applicable to cities everywhere

Cubipod® Armor Design in Depth-Limited Regular Wave-Breaking Conditions

[EN] Armor stability formulas for mound breakwaters are commonly based on 2D small-scale physical tests conducted in non-overtopping and non-breaking conditions. However, most of the breakwaters built around the world are located in breaking or partially-breaking wave conditions, where they must withstand design storms having some percentage of large waves breaking before they reach the structure. In these cases, the design formulas for non-breaking wave conditions are not fully valid. This paper describes the specific 2D physical model tests carried out to analyze the trunk hydraulic stability of single- and double-layer Cubipod (R) armors in depth-limited regular wave breaking and non-overtopping conditions with horizontal foreshore (m = 0) and armor slope (alpha) with cot alpha = 1.5. An experimental methodology was established to ensure that 100 waves attacked the armor layer with the most damaging combination of wave height (H) and wave period (T) for the given water depth (h(s)). Finally, for a given water depth, empirical formulas were obtained to estimate the Cubipod (R) size which made the armor stable regardless of the deep-water wave storm.This research was funded by Conselleria d'Educacio, Investigacio, Cultura i Esport (Generalitat Valenciana) under grant GV/2017/031.Gómez-Martín, ME.; Herrera, MP.; Gonzalez-Escriva, J.; Medina, JR. (2018). Cubipod® Armor Design in Depth-Limited Regular Wave-Breaking Conditions. Journal of Marine Science and Engineering. 6(4):150-161. https://doi.org/10.3390/jmse6040150S15016164Herrera, M. P., Gómez-Martín, M. E., & Medina, J. R. (2017). Hydraulic stability of rock armors in breaking wave conditions. Coastal Engineering, 127, 55-67. doi:10.1016/j.coastaleng.2017.06.010Battjes, J. A., & Groenendijk, H. W. (2000). Wave height distributions on shallow foreshores. Coastal Engineering, 40(3), 161-182. doi:10.1016/s0378-3839(00)00007-7Medina, J. R., & Gómez-Martín, M. E. (2012). KD AND SAFETY FACTORS OF CONCRETE ARMOR UNITS. Coastal Engineering Proceedings, 1(33), 29. doi:10.9753/icce.v33.structures.29Melby, J. A., & Kobayashi, N. (1998). Progression and Variability of Damage on Rubble Mound Breakwaters. Journal of Waterway, Port, Coastal, and Ocean Engineering, 124(6), 286-294. doi:10.1061/(asce)0733-950x(1998)124:6(286)Van Gent, M. R. A. (2013). Rock stability of rubble mound breakwaters with a berm. Coastal Engineering, 78, 35-45. doi:10.1016/j.coastaleng.2013.03.003Celli, D., Pasquali, D., De Girolamo, P., & Di Risio, M. (2018). Effects of submerged berms on the stability of conventional rubble mound breakwaters. Coastal Engineering, 136, 16-25. doi:10.1016/j.coastaleng.2018.01.011Concrete Layer Innovation (CLI) http://www.concretelayer.com/documentationGuidelines for Xbloc Concept Designs https://www.xbloc.com/sites/default/files/domain-671/documents/xbloc-design-guidelines-2014-671-15039173271578936988.pdfGómez-Martín, M. E., & Medina, J. R. (2014). Heterogeneous Packing and Hydraulic Stability of Cube and Cubipod Armor Units. Journal of Waterway, Port, Coastal, and Ocean Engineering, 140(1), 100-108. doi:10.1061/(asce)ww.1943-5460.0000223Medina, J. R., Hudspeth, R. T., & Fassardi, C. (1994). Breakwater Armor Damage due to Wave Groups. Journal of Waterway, Port, Coastal, and Ocean Engineering, 120(2), 179-198. doi:10.1061/(asce)0733-950x(1994)120:2(179)Herrera, M. P., & Medina, J. R. (2015). Toe berm design for very shallow waters on steep sea bottoms. Coastal Engineering, 103, 67-77. doi:10.1016/j.coastaleng.2015.06.005Herrera, M. P., Molines, J., & Medina, J. R. (2016). Hydraulic stability of nominal and sacrificial toe berms for mound breakwaters on steep sea bottoms. Coastal Engineering, 114, 361-368. doi:10.1016/j.coastaleng.2016.05.00

Air conditioning production by a single effect absorption cooling machine directly coupled to a solar collector field. Application to Spanish climates

Due to the increasing energy consumption of air conditioning in buildings and the need to decrease the fossil CO2 emissions to the environment, the interest of using renewable energy sources shows up stronger than ever. We present a general study whose aim is to propose a method to evaluate an upper bound in the potential of solar cooling by using some simplified models. As an example it has been applied to the very diverse climates of Spain. In the paper it has been assumed a direct solar coupling between the solar collector field and a single effect absorption cooling machine, without any intermediate solar storage tank. An equation is obtained that shows the dependence of the generator/solar-collectors equilibrium temperature on basic design parameters of the system (absorption machine-solar collectors). The paper analyzes the effect of these on the total amount of cooling produced along a typical mean year and the peak cooling power. The paper also includes a discussion on how to estimate the values and what is their physical meaning of the parameters which define the behavior of real absorption machines. Finally tables are included for the 12 climates of Spain that can be used as an example of how to make a quick pre-sizing of such direct coupled system. The classification of the Spanish climates is based on general data (average monthly total horizontal solar radiation, average monthly dry temperature, etc.) and the results could be generalized for climates with the same severity. Moreover if hourly weather data is available for any place (like tmy2, bin, epw, etc. files), the procedure can be applied without further changes.Sarabia Escrivà, EJ.; Lamas Sivila, EV.; Soto Francés, VM. (2011). Air conditioning production by a single effect absorption cooling machine directly coupled to a solar collector field. Application to Spanish climates. Solar Energy. 85(9):2108-2121. doi:10.1016/j.solener.2011.05.019S2108212185

Integration of GMR sensors with different technologies

Less than thirty years after the giant magnetoresistance (GMR) effect was described, GMR sensors are the preferred choice in many applications demanding the measurement of low magnetic fields in small volumes. This rapid deployment from theoretical basis to market and state-of-the-art applications can be explained by the combination of excellent inherent properties with the feasibility of fabrication, allowing the real integration with many other standard technologies. In this paper, we present a review focusing on how this capability of integration has allowed the improvement of the inherent capabilities and, therefore, the range of application of GMR sensors. After briefly describing the phenomenological basis, we deal on the benefits of low temperature deposition techniques regarding the integration of GMR sensors with flexible (plastic) substrates and pre-processed CMOS chips. In this way, the limit of detection can be improved by means of bettering the sensitivity or reducing the noise. We also report on novel fields of application of GMR sensors by the recapitulation of a number of cases of success of their integration with different heterogeneous complementary elements. We finally describe three fully functional systems, two of them in the bio-technology world, as the proof of how the integrability has been instrumental in the meteoric development of GMR sensors and their applications.Peer ReviewedPostprint (published version

Design and assessment of an efficient and equitable dynamic urban water tariff. Application to the city of Valencia, Spain

Water pricing policies have a large and still relatively untapped potential to foster more efficient management of water resources in scarcity situations. This work contributes a framework for designing equitable, financially stable and economically efficient urban water tariffs. A hydroeconomic simulation model links the marginal value of water, which reflects water scarcity given its competing uses, to water supply reservoir levels. Varying reservoir levels trigger variations in the second block of the proposed two-block increasing-rate tariff; these variations then reflect water's value at that time. The work contrasts the two-block scarcity tariff with a constant volumetric rate for the city of Valencia, Spain, and the drought-prone Jucar basin, where most of 430,000 households are equipped with smart meters. Results show urban consumption is reduced by 18% in the driest years, lowering basin-wide scarcity costs by 34%

Evolutionary Analysis of Mitogenomes from Parasitic and Free-Living Flatworms

Copyright: © 2015 Solà et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article

Echinoderms have bilateral tendencies

Echinoderms take many forms of symmetry. Pentameral symmetry is the major form and the other forms are derived from it. However, the ancestors of echinoderms, which originated from Cambrian period, were believed to be bilaterians. Echinoderm larvae are bilateral during their early development. During embryonic development of starfish and sea urchins, the position and the developmental sequence of each arm are fixed, implying an auxological anterior/posterior axis. Starfish also possess the Hox gene cluster, which controls symmetrical development. Overall, echinoderms are thought to have a bilateral developmental mechanism and process. In this article, we focused on adult starfish behaviors to corroborate its bilateral tendency. We weighed their central disk and each arm to measure the position of the center of gravity. We then studied their turning-over behavior, crawling behavior and fleeing behavior statistically to obtain the center of frequency of each behavior. By joining the center of gravity and each center of frequency, we obtained three behavioral symmetric planes. These behavioral bilateral tendencies might be related to the A/P axis during the embryonic development of the starfish. It is very likely that the adult starfish is, to some extent, bilaterian because it displays some bilateral propensity and has a definite behavioral symmetric plane. The remainder of bilateral symmetry may have benefited echinoderms during their evolution from the Cambrian period to the present

Sequencing and Analysis of the Mediterranean Amphioxus (Branchiostoma lanceolatum) Transcriptome

BACKGROUND: The basally divergent phylogenetic position of amphioxus (Cephalochordata), as well as its conserved morphology, development and genetics, make it the best proxy for the chordate ancestor. Particularly, studies using the amphioxus model help our understanding of vertebrate evolution and development. Thus, interest for the amphioxus model led to the characterization of both the transcriptome and complete genome sequence of the American species, Branchiostoma floridae. However, recent technical improvements allowing induction of spawning in the laboratory during the breeding season on a daily basis with the Mediterranean species Branchiostoma lanceolatum have encouraged European Evo-Devo researchers to adopt this species as a model even though no genomic or transcriptomic data have been available. To fill this need we used the pyrosequencing method to characterize the B. lanceolatum transcriptome and then compared our results with the published transcriptome of B. floridae. RESULTS: Starting with total RNA from nine different developmental stages of B. lanceolatum, a normalized cDNA library was constructed and sequenced on Roche GS FLX (Titanium mode). Around 1.4 million of reads were produced and assembled into 70,530 contigs (average length of 490 bp). Overall 37% of the assembled sequences were annotated by BlastX and their Gene Ontology terms were determined. These results were then compared to genomic and transcriptomic data of B. floridae to assess similarities and specificities of each species. CONCLUSION: We obtained a high-quality amphioxus (B. lanceolatum) reference transcriptome using a high throughput sequencing approach. We found that 83% of the predicted genes in the B. floridae complete genome sequence are also found in the B. lanceolatum transcriptome, while only 41% were found in the B. floridae transcriptome obtained with traditional Sanger based sequencing. Therefore, given the high degree of sequence conservation between different amphioxus species, this set of ESTs may now be used as the reference transcriptome for the Branchiostoma genus