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Physical reasons suggested in [J.B. Hartle, S.W. Hawking, Wave function of the universe, Phys. Rev. D41 (1990) 1815-1834] for the Quantum Gravity Problem lead us to study type-changing metrics on a manifold. The most interesting cases are Transverse Rieniann-Lorentz Manifolds. Here we study the conformal geometry of such manifolds., Depto. de Álgebra, Geometría y Topología, Fac. de Ciencias Matemáticas, TRUE, pub

Contains fulltext : 220280.pdf (Publisher’s version ) (Closed access)

Contains fulltext : 220280.pdf (Publisher’s version ) (Closed access)

Contains fulltext : 220280.pdf (Publisher’s version ) (Closed access)

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or Covid-19), which began as an epidemic in China and spread globally as a pandemic, has necessitated resource management to meet emergency needs of Covid-19 patients and other emergent cases. We have conducted a survey to analyze caseload and measures to adapt indications for a perception of crisis. Methods: We constructed a questionnaire to survey a snapshot of neurosurgical activity, resources, and indications during 1 week with usual activity in December 2019 and 1 week during SARS-CoV-2 pandemic in March 2020. The questionnaire was sent to 34 neurosurgical departments in Europe; 25 departments returned responses within 5 days. Results: We found unexpectedly large differences in resources and indications already before the pandemic. Differences were also large in how much practice and resources changed during the pandemic. Neurosurgical beds and neuro-intensive care beds were significantly decreased from December 2019 to March 2020. The utilization of resources decreased via less demand for care of brain injuries and subarachnoid hemorrhage, postponing surgery and changed surgical indications as a method of rationing resources. Twenty departments (80%) reduced activity extensively, and the same proportion stated that they were no longer able to provide care according to legitimate medical needs. Conclusion: Neurosurgical centers responded swiftly and effectively to a sudden decrease of neurosurgical capacity due to relocation of resources to pandemic care. The pandemic led to rationing of neurosurgical care in 80% of responding centers. We saw a relation between resources before the pandemic and ability to uphold neurosurgical services. The observation of extensive differences of available beds provided an opportunity to show how resources that had been restricted already under normal conditions translated to rationing of care that may not be acceptable to the public of seemingly affluent

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Rearing in enriched environment (EE) improves the recuperation in animal models of Parkinson's disease (PD). Administration of TiO2-nanowired cerebrolysin (CBL) could represent an additional strategy to protect or repair the nigrostriatal system. This study aims to explore morphofunctional and biochemical changes in a preclinical stage of PD testing the synergistic efficiency of combining both strategies, housing in EE, and nanodelivery of CBL. Sprague-Dawley male rats receiving intrastriatally 6-hydroxydopamine after a short evolution time were segregated into CBL group (rats receiving nanowired CBL), EE group (rats housed in EE), CBL + EE group (rats housed in EE and receiving nanowired CBL), and control group (rats without additional treatment). Prodromic stage and treatment effects were characterized by the presence of motor symptoms (amphetamine-induced rotational behavior test). Tyrosine hydroxylase (TH) immunohistochemistry and Western blot (p-Akt/Akt and p-ERK/ERK 1/2 as survival markers and caspase-3 as apoptotic marker) were performed in striatum and SN. A decrease in motor symptoms was shown by rats receiving CBL. EE monitoring cages revealed that rats from CBL + EE group showed more significant number of laps in the wheel than EE group. In SN, CBL + EE group also presented the highest neuronal density. Moreover, p-Akt/Akt and p-ERK/ERK 1/2 ratio was significant higher and caspase-3 expression was lower in CBL + EE group. In conclusion, the combination of CBL and EE provided evidence of neuoprotective-neurorestorative mechanisms by which this combined strategy promoted morphofunctional improvement by activation of survival pathways after dopamine depletion in a preclinical model of PD.

This paper presents a review of the state-of-the-art in understanding and quantification of the Mediterranean heat and mass (i.e. salt and water) budgets. The budgets are decomposed into a basin averaged surface component, lateral boundary components (through the Gibraltar and the Dardanelles Straits), a river input component and a content change component. An assessment of the different methods and observational products that have been used to quantify each of these components is presented. The values for the long term average of each component are also updated based on existing literature and a first estimate of heat fluxes associated with the riverine input has been produced. Special emphasis is put on the characterization of associated uncertainties and proposals for advancing current knowledge are presented for each budget component. With the present knowledge of the different components, the Mediterranean budgets can be closed within the range of uncertainty. However, the uncertainty range remains relatively high for several terms, particularly the basin averaged surface heat fluxes. Consequently, the basin averaged heat budget remains more strongly constrained by the Strait of Gibraltar heat transport than by the surface heat flux. It is worth remarking that if a short (∼few years) averaging period is used, then the heat content change must also be considered to constrain the heat budget. Concerning the water and salt fluxes, the highest uncertainties are found in the direct estimates of the Strait of Gibraltar water and salt transport. Therefore, the indirect estimate of those transports using the budget closure leads to smaller uncertainties than the estimates based on direct observations. Finally, estimates of Mediterranean heat and salt content trends are also reviewed. However, these cannot be improved through the indirect estimates due to the large temporal uncertainties associated to the surface fluxes and the fluxes through Gibraltar. The consequences

This paper presents a review of the state-of-the-art in understanding and quantification of the Mediterranean heat and mass (i.e. salt and water) budgets. The budgets are decomposed into a basin averaged surface component, lateral boundary components (through the Gibraltar and the Dardanelles Straits), a river input component and a content change component. An assessment of the different methods and observational products that have been used to quantify each of these components is presented. The values for the long term average of each component are also updated based on existing literature and a first estimate of heat fluxes associated with the riverine input has been produced. Special emphasis is put on the characterization of associated uncertainties and proposals for advancing current knowledge are presented for each budget component. With the present knowledge of the different components, the Mediterranean budgets can be closed within the range of uncertainty. However, the uncertainty range remains relatively high for several terms, particularly the basin averaged surface heat fluxes. Consequently, the basin averaged heat budget remains more strongly constrained by the Strait of Gibraltar heat transport than by the surface heat flux. It is worth remarking that if a short (∼few years) averaging period is used, then the heat content change must also be considered to constrain the heat budget. Concerning the water and salt fluxes, the highest uncertainties are found in the direct estimates of the Strait of Gibraltar water and salt transport. Therefore, the indirect estimate of those transports using the budget closure leads to smaller uncertainties than the estimates based on direct observations. Finally, estimates of Mediterranean heat and salt content trends are also reviewed. However, these cannot be improved through the indirect estimates due to the large temporal uncertainties associated to the surface fluxes and the fluxes through Gibraltar. The consequences

The Industry 4.0 Italian plan is the new attempt of the National Government in Italy to adopt a comprehensive industrial policy aimed to adapt the industrial sector to the new trajectories of manufacturing. A variety of policy plans and interventions have been recently developed in order to sustain these processes everywhere in Europe. . The 9 enabling technologies identified in the so called ‘Calenda plan’ (from the Italian ministry of economic development name, coordinated the plan writing) are not just a list of industrial technologies available, but are a chance for (re)create a new business model in the factory 4.0, but more and more in the ‘social environment’ 4.0 where the whole value chain in a business company need to be re-thought. An analysis of the potential impact of these policy frameworks has still to be implemented. This paper aims to disentangle the relationship between policies and the Italian manufacturing starting from an overview of the industrial policies in Italy and raising the main problems and contradictions potentially stemming out from the Italian plan.

Peer Reviewed, Postprint (author's final draft)

It is widely known that market orientation (MO) and customer value help companies achieve sustainable sales growth over time. Nevertheless, one cannot ignore the existence of a gap on how to measure this relationship. Following this idea, this study proposes six fuzzy key performance indicators that aims to measure customer retention and loyalty of the portfolio. The work uses 300 sales executives. This exploratory study concludes that indicators such as MO, customer orientation (CO), degree of CO value of sales force, innovation capability, lifetime value, and customer service quality positively influence customer retention and loyalty portfolio.

Purpose: This special issue of the Journal of Business & Industrial Marketing, entitled “Business, Industrial Marketing and Uncertainty”, presents selected extended studies that were presented at the European Academy of Management and Business Economics Conference (AEDEM 2012). Design/methodology/approach: The main focus of this year was reflected in the slogan: “Creating new opportunities in an uncertain environment”. The objective was to show the importance that uncertainty has in our current world, strongly affected by many complexities and modern developments, especially through the new technological advances. Findings: One fundamental reason that explains the economic crisis is that the government and companies were not well prepared for these critical situations. And the main justification for this is that they did not have enough information. Otherwise, they would have tried any possible strategy to avoid the crisis. Usually, uncertainty is defined as the situation with unknown information in the environment. Originality/value: From a theoretical perspective, the problem here is that enterprises and governments should assess the information and the uncertainty in a more appropriate way. Usually, they have some studies in this direction, but many times, it is not enough, as it was proved in the last economic crisis.

The fungus Candida rugosa secretes an extracellular lipase whose production is induced by the addition of fatty acids to the culture broth. This lipase is indeed composed by several protein isoforms partly differing in their catalytic properties. Synthesis and secretion of lipase proteins by C. rugosa cells were studied in culture media containing either glucose or oleic acid as the carbon source. It was shown that, according to their regulation, lipase-encoding genes might be grouped in two classes, one of which is constitutively expressed and the other is induced by fatty acids. The synthesis of inducible enzymes is inhibited at the level of transcription by the addition of glucose and, conversely, oleic acid appears to hinder the synthesis of the constitutive lipase. Growth conditions supporting high level expression both in batch and in continuous culture give rise to the intracellular accumulation of enzyme, possibly due to the existence of a rate-limiting step in the transport of the newly synthesized protein. These results suggest the possibility to develop fermentation processes aimed at the control of the enzyme composition.

This paper is the outcome of a workshop held in Rome in November 2011 on the occasion of the 25th anniversary of the POEM (Physical Oceanography of the Eastern Mediterranean) program. In the workshop discussions, a number of unresolved issues were identified for the physical and biogeochemical properties of the Mediterranean Sea as a whole, i.e., comprising the Western and Eastern sub-basins. Over the successive two years, the related ideas were discussed among the group of scientists who participated in the workshop and who have contributed to the writing of this paper. Three major topics were identified, each of them being the object of a section divided into a number of different sub-sections, each addressing a specific physical, chemical or biological issue: 1. Assessment of basin-wide physical/biochemical properties, of their variability and interactions. 2. Relative importance of external forcing functions (wind stress, heat/moisture fluxes, forcing through straits) vs. internal variability. 3. Shelf/deep sea interactions and exchanges of physical/biogeochemical properties and how they affect the sub-basin circulation and property distribution. Furthermore, a number of unresolved scientific/methodological issues were also identified and are reported in each sub-section after a short discussion of the present knowledge. They represent the collegial consensus of the scientists contributing to the paper. Naturally, the unresolved issues presented here constitute the choice of the authors and therefore they may not be exhaustive and/or complete. The overall goal is to stimulate a broader interdisciplinary discussion among the scientists of the Mediterranean oceanographic community, leading to enhanced collaborative efforts and exciting future discoveries.

This paper is the outcome of a workshop held in Rome in November 2011 on the occasion of the 25th anniversary of the POEM (Physical Oceanography of the Eastern Mediterranean) program. In the workshop discussions, a number of unresolved issues were identified for the physical and biogeochemical properties of the Mediterranean Sea as a whole, i.e., comprising the Western and Eastern sub-basins. Over the successive two years, the related ideas were discussed among the group of scientists who participated in the workshop and who have contributed to the writing of this paper. Three major topics were identified, each of them being the object of a section divided into a number of different sub-sections, each addressing a specific physical, chemical or biological issue: 1. Assessment of basin-wide physical/biochemical properties, of their variability and interactions. 2. Relative importance of external forcing functions (wind stress, heat/moisture fluxes, forcing through straits) vs. internal variability. 3. Shelf/deep sea interactions and exchanges of physical/biogeochemical properties and how they affect the sub-basin circulation and property distribution. Furthermore, a number of unresolved scientific/methodological issues were also identified and are reported in each sub-section after a short discussion of the present knowledge. They represent the collegial consensus of the scientists contributing to the paper. Naturally, the unresolved issues presented here constitute the choice of the authors and therefore they may not be exhaustive and/or complete. The overall goal is to stimulate a broader interdisciplinary discussion among the scientists of the Mediterranean oceanographic community, leading to enhanced collaborative efforts and exciting future discoveries.

This paper is the outcome of a workshop held in Rome in November 2011 on the occasion of the 25th anniversary of the POEM (Physical Oceanography of the Eastern Mediterranean) program. In the workshop discussions, a number of unresolved issues were identified for the physical and biogeochemical properties of the Mediterranean Sea as a whole, i.e., comprising the Western and Eastern sub-basins. Over the successive two years, the related ideas were discussed among the group of scientists who participated in the workshop and who have contributed to the writing of this paper. Three major topics were identified, each of them being the object of a section divided into a number of different sub-sections, each addressing a specific physical, chemical or biological issue: 1. Assessment of basin-wide physical/biochemical properties, of their variability and interactions. 2. Relative importance of external forcing functions (wind stress, heat/moisture fluxes, forcing through straits) vs. internal variability. 3. Shelf/deep sea interactions and exchanges of physical/biogeochemical properties and how they affect the sub-basin circulation and property distribution. Furthermore, a number of unresolved scientific/methodological issues were also identified and are reported in each sub-section after a short discussion of the present knowledge. They represent the collegial consensus of the scientists contributing to the paper. Naturally, the unresolved issues presented here constitute the choice of the authors and therefore they may not be exhaustive and/or complete. The overall goal is to stimulate a broader interdisciplinary discussion among the scientists of the Mediterranean oceanographic community, leading to enhanced collaborative efforts and exciting future discoveries.

This paper is the outcome of a workshop held in Rome in November 2011 on the occasion of the 25th anniversary of the POEM (Physical Oceanography of the Eastern Mediterranean) program. In the workshop discussions, a number of unresolved issues were identified for the physical and biogeochemical properties of the Mediterranean Sea as a whole, i.e., comprising the Western and Eastern sub-basins. Over the successive two years, the related ideas were discussed among the group of scientists who participated in the workshop and who have contributed to the writing of this paper. Three major topics were identified, each of them being the object of a section divided into a number of different sub-sections, each addressing a specific physical, chemical or biological issue: 1. Assessment of basin-wide physical/biochemical properties, of their variability and interactions. 2. Relative importance of external forcing functions (wind stress, heat/moisture fluxes, forcing through straits) vs. internal variability. 3. Shelf/deep sea interactions and exchanges of physical/biogeochemical properties and how they affect the sub-basin circulation and property distribution. Furthermore, a number of unresolved scientific/methodological issues were also identified and are reported in each sub-section after a short discussion of the present knowledge. They represent the collegial consensus of the scientists contributing to the paper. Naturally, the unresolved issues presented here constitute the choice of the authors and therefore they may not be exhaustive and/or complete. The overall goal is to stimulate a broader interdisciplinary discussion among the scientists of the Mediterranean oceanographic community, leading to enhanced collaborative efforts and exciting future discoveries.

The long-term monitoring of basic hydrological parameters (temperature and salinity), collected as time series with adequate temporal resolution (i.e. with a sampling interval allowing the resolution of all important timescales) in key places of the Mediterranean Sea (straits and channels, zones of dense water formation, deep parts of the basins), constitute a priority in the context of global changes. This led CIESM (The Mediterranean Science Commission) to support, since 2002, the HYDROCHANGES programme (www.ciesm.org/marine/programs/hydrochanges.htm), a network of autonomous conductivity, temperature, and depth (CTD) sensors, deployed on mainly short and easily manageable subsurface moorings, within the core of a certain water mass. The HYDROCHANGES strategy is twofold and develops on different scales. To get information about long-term changes of hydrological characteristics, long time series are needed. But before these series are long enough they allow the detection of links between them at shorter timescales that may provide extremely valuable information about the functioning of the Mediterranean Sea. The aim of this paper is to present the history of the programme and the current set-up of the network (monitored sites, involved groups) as well as to provide for the first time an overview of all the time series collected under the HYDROCHANGES umbrella, discussing the results obtained thanks to the programme.

The long-term monitoring of basic hydrological parameters (temperature and salinity), collected as time series with adequate temporal resolution (i.e. with a sampling interval allowing the resolution of all important timescales) in key places of the Mediterranean Sea (straits and channels, zones of dense water formation, deep parts of the basins), constitute a priority in the context of global changes. This led CIESM (The Mediterranean Science Commission) to support, since 2002, the HYDROCHANGES programme (www.ciesm.org/marine/programs/hydrochanges.htm), a network of autonomous conductivity, temperature, and depth (CTD) sensors, deployed on mainly short and easily manageable subsurface moorings, within the core of a certain water mass. The HYDROCHANGES strategy is twofold and develops on different scales. To get information about long-term changes of hydrological characteristics, long time series are needed. But before these series are long enough they allow the detection of links between them at shorter timescales that may provide extremely valuable information about the functioning of the Mediterranean Sea. The aim of this paper is to present the history of the programme and the current set-up of the network (monitored sites, involved groups) as well as to provide for the first time an overview of all the time series collected under the HYDROCHANGES umbrella, discussing the results obtained thanks to the programme.

The long-term monitoring of basic hydrological parameters (temperature and salinity), collected as time series with adequate temporal resolution (i.e. with a sampling interval allowing the resolution of all important timescales) in key places of the Mediterranean Sea (straits and channels, zones of dense water formation, deep parts of the basins), constitute a priority in the context of global changes. This led CIESM (The Mediterranean Science Commission) to support, since 2002, the HYDROCHANGES programme (www.ciesm.org/marine/programs/hydrochanges.htm), a network of autonomous conductivity, temperature, and depth (CTD) sensors, deployed on mainly short and easily manageable subsurface moorings, within the core of a certain water mass. The HYDROCHANGES strategy is twofold and develops on different scales. To get information about long-term changes of hydrological characteristics, long time series are needed. But before these series are long enough they allow the detection of links between them at shorter timescales that may provide extremely valuable information about the functioning of the Mediterranean Sea. The aim of this paper is to present the history of the programme and the current set-up of the network (monitored sites, involved groups) as well as to provide for the first time an overview of all the time series collected under the HYDROCHANGES umbrella, discussing the results obtained thanks to the programme.

Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 116 (2011): C12026, doi:10.1029/2011JC007093., The baroclinic response to barotropic tidal forcing in the Camarinal Sill area, within the Strait of Gibraltar, is investigated with a three-dimensional, fully nonlinear, nonhydrostatic numerical model. The aim of numerical efforts was the assessment of three-dimensional effects, which are potentially significant in the area because of rather irregular bottom topography, variable background stratification, and complex structure of barotropic tides. Model results reveal a complex baroclinic response under relatively moderate flood tidal currents, which includes the formation of internal hydraulic jumps upstream of the sill, internal cross waves close to the channel walls, and a plunging pycnocline at the lee side of the sill crest. These structures exhibit significant cross-channel spatial dependence and may appear to be aligned together across the channel. This fact makes their identification difficult from the surface pattern captured by remote sensing images. Under strong barotropic forcing (spring tides) the upstream hydraulic jumps are shifted to the lee side of Camarinal Sill, where a single internal hydraulic jump is formed. Significant first- and second-mode hydraulic jumps are also generated near smaller secondary sills in Tangier basin, thus extending the occurrence of intense water mixing and energy dissipation to other zones of the strait., This work is a contribution to the Spanishfunded National Project INGRES-2 (CTM2006-02326). Partial financial support from Acción Complementaria CTM2009-05810/E (Spanish Ministry of Science and Innovation) and project P08-RNM-3738 from Plan Andaluz de Investigación (Andalucia regional government) is acknowledged., 2012-06-17

Author Posting. © American Geophysical Union, 2011. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 116 (2011): C12026, doi:10.1029/2011JC007093., The baroclinic response to barotropic tidal forcing in the Camarinal Sill area, within the Strait of Gibraltar, is investigated with a three-dimensional, fully nonlinear, nonhydrostatic numerical model. The aim of numerical efforts was the assessment of three-dimensional effects, which are potentially significant in the area because of rather irregular bottom topography, variable background stratification, and complex structure of barotropic tides. Model results reveal a complex baroclinic response under relatively moderate flood tidal currents, which includes the formation of internal hydraulic jumps upstream of the sill, internal cross waves close to the channel walls, and a plunging pycnocline at the lee side of the sill crest. These structures exhibit significant cross-channel spatial dependence and may appear to be aligned together across the channel. This fact makes their identification difficult from the surface pattern captured by remote sensing images. Under strong barotropic forcing (spring tides) the upstream hydraulic jumps are shifted to the lee side of Camarinal Sill, where a single internal hydraulic jump is formed. Significant first- and second-mode hydraulic jumps are also generated near smaller secondary sills in Tangier basin, thus extending the occurrence of intense water mixing and energy dissipation to other zones of the strait., This work is a contribution to the Spanishfunded National Project INGRES-2 (CTM2006-02326). Partial financial support from Acción Complementaria CTM2009-05810/E (Spanish Ministry of Science and Innovation) and project P08-RNM-3738 from Plan Andaluz de Investigación (Andalucia regional government) is acknowledged., 2012-06-17

Four-year time series of observations in Espartel sill at the western part of the Strait of Gibraltar have been analyzed in order to investigate the variability of the Mediterranean outflow. It is assumed that the observed variability comes from the changing properties of the dense waters that are located at the maximum depth from where they can be uplifted in the upstream basin (Alboran Sea, inside the Mediterranean Sea) and evacuated through the strait. From this perspective, the following three mechanisms are investigated: (1) the replenishment of the deep basin by newly formed Western Mediterranean Deep Water that, depending on its density, can either uplift old resident waters or lay above them leaving in any case a cold signature in the temperature series; (2) the presence/absence of the energetic anticyclonic gyres in the Alboran Sea, particularly the western one, which can transfer momentum to the underlying Mediterranean vein and provide it with additional energy to ascend over the sills of the strait; and (3) the meteorologically enhanced flows that follow the rapid changes of atmospheric pressure over the western Mediterranean basin, which would be able to aspire deeper waters residing in the upstream basin. The three mechanisms act on different timescales, from annual in case (1) to monthly in case (2) to weekly in case (3) although these two latter are modulated annually by the seasonal prevalence of the western Alboran gyre in summer and of the strong meteorologically driven fluctuations in winter. The mechanisms overlap at annual timescales making it difficult to separate out the different contributions.

[1] Four‐year time series of observations in Espartel sill at the western part of the Strait of Gibraltar have been analyzed in order to investigate the variability of the Mediterranean outflow. It is assumed that the observed variability comes from the changing properties of the dense waters that are located at the maximum depth from where they can be uplifted in the upstream basin (Alborán Sea, inside the Mediterranean Sea) and evacuated through the strait. From this perspective, the following three mechanisms are investigated: (1) the replenishment of the deep basin by newly formed Western Mediterranean Deep Water that, depending on its density, can either uplift old resident waters or lay above them leaving in any case a cold signature in the temperature series; (2) the presence/absence of the energetic anticyclonic gyres in the Alborán Sea, particularly the western one, which can transfer momentum to the underlying Mediterranean vein and provide it with additional energy to ascend over the sills of the strait; and (3) the meteorologically enhanced flows that follow the rapid changes of atmospheric pressure over the western Mediterranean basin, which would be able to aspire deeper waters residing in the upstream basin. The three mechanisms act on different timescales, from annual in case (1) to monthly in case (2) to weekly in case (3) although these two latter are modulated annually by the seasonal prevalence of the western Alborán gyre in summer and of the strong meteorologically driven fluctuations in winter. The mechanisms overlap at annual timescales making it difficult to separate out the different contributions.

Four-year time series of observations in Espartel sill at the western part of the Strait of Gibraltar have been analyzed in order to investigate the variability of the Mediterranean outflow. It is assumed that the observed variability comes from the changing properties of the dense waters that are located at the maximum depth from where they can be uplifted in the upstream basin (Alboran Sea, inside the Mediterranean Sea) and evacuated through the strait. From this perspective, the following three mechanisms are investigated: (1) the replenishment of the deep basin by newly formed Western Mediterranean Deep Water that, depending on its density, can either uplift old resident waters or lay above them leaving in any case a cold signature in the temperature series; (2) the presence/absence of the energetic anticyclonic gyres in the Alboran Sea, particularly the western one, which can transfer momentum to the underlying Mediterranean vein and provide it with additional energy to ascend over the sills of the strait; and (3) the meteorologically enhanced flows that follow the rapid changes of atmospheric pressure over the western Mediterranean basin, which would be able to aspire deeper waters residing in the upstream basin. The three mechanisms act on different timescales, from annual in case (1) to monthly in case (2) to weekly in case (3) although these two latter are modulated annually by the seasonal prevalence of the western Alboran gyre in summer and of the strong meteorologically driven fluctuations in winter. The mechanisms overlap at annual timescales making it difficult to separate out the different contributions.

Four-year time series of observations in Espartel sill at the western part of the Strait of Gibraltar have been analyzed in order to investigate the variability of the Mediterranean outflow. It is assumed that the observed variability comes from the changing properties of the dense waters that are located at the maximum depth from where they can be uplifted in the upstream basin (Alboran Sea, inside the Mediterranean Sea) and evacuated through the strait. From this perspective, the following three mechanisms are investigated: (1) the replenishment of the deep basin by newly formed Western Mediterranean Deep Water that, depending on its density, can either uplift old resident waters or lay above them leaving in any case a cold signature in the temperature series; (2) the presence/absence of the energetic anticyclonic gyres in the Alboran Sea, particularly the western one, which can transfer momentum to the underlying Mediterranean vein and provide it with additional energy to ascend over the sills of the strait; and (3) the meteorologically enhanced flows that follow the rapid changes of atmospheric pressure over the western Mediterranean basin, which would be able to aspire deeper waters residing in the upstream basin. The three mechanisms act on different timescales, from annual in case (1) to monthly in case (2) to weekly in case (3) although these two latter are modulated annually by the seasonal prevalence of the western Alboran gyre in summer and of the strong meteorologically driven fluctuations in winter. The mechanisms overlap at annual timescales making it difficult to separate out the different contributions.

[1] Four‐year time series of observations in Espartel sill at the western part of the Strait of Gibraltar have been analyzed in order to investigate the variability of the Mediterranean outflow. It is assumed that the observed variability comes from the changing properties of the dense waters that are located at the maximum depth from where they can be uplifted in the upstream basin (Alborán Sea, inside the Mediterranean Sea) and evacuated through the strait. From this perspective, the following three mechanisms are investigated: (1) the replenishment of the deep basin by newly formed Western Mediterranean Deep Water that, depending on its density, can either uplift old resident waters or lay above them leaving in any case a cold signature in the temperature series; (2) the presence/absence of the energetic anticyclonic gyres in the Alborán Sea, particularly the western one, which can transfer momentum to the underlying Mediterranean vein and provide it with additional energy to ascend over the sills of the strait; and (3) the meteorologically enhanced flows that follow the rapid changes of atmospheric pressure over the western Mediterranean basin, which would be able to aspire deeper waters residing in the upstream basin. The three mechanisms act on different timescales, from annual in case (1) to monthly in case (2) to weekly in case (3) although these two latter are modulated annually by the seasonal prevalence of the western Alborán gyre in summer and of the strong meteorologically driven fluctuations in winter. The mechanisms overlap at annual timescales making it difficult to separate out the different contributions.

The output of a two-layer hydrodynamic model along a west–east section of the Gibraltar Strait is used to estimate tidal induced mixing between the Mediterranean and Atlantic water layers and to simulate the effects of mixing processes on biogeochemical fluxes and the pelagic community of the area. The hydrodynamic model is used to estimate interfacial mixing and water advection which drive the dynamics of the pelagic community. The model was run for 13 months, in order to analyse the effect of annual modulations in tidal amplitude on mixing. Incorporation of a third intermediate layer leads to a significant improvement in the model results, showing the necessity for a three layer circulation scheme when modelling biogeochemical processes in the Strait of Gibraltar. Pelagic processes are modelled using a simple Nutrient–Phytoplankton–Zooplankton (NPZ) model. The intense physical mixing and advection in the channel are the main influence on plankton dynamics in the area. It is found that residence times within the channel are so short that phytoplankton communities cannot grow appreciably during their transit. As a consequence, the use of a more sophisticated biogeochemical model does not lead to significant changes in the results obtained. According to the model, mixing over the Camarinal Sill causes an average of 16% of the out-flowing nutrients to be returned back to the Mediterranean. This fraction varies between 4% and 35% as a function of the tidal amplitude. The comparison of the model results with field data suggests that in order to obtain an accurate simulation of the plankton ecosystem dynamics in the strait, it is necessary to take into account the full horizontal flow, as recirculation and coast-channel interactions seems to be very important processes in explaining the biological patterns in the area.

The output of a two-layer hydrodynamic model along a west–east section of the Gibraltar Strait is used to estimate tidal induced mixing between the Mediterranean and Atlantic water layers and to simulate the effects of mixing processes on biogeochemical fluxes and the pelagic community of the area. The hydrodynamic model is used to estimate interfacial mixing and water advection which drive the dynamics of the pelagic community. The model was run for 13 months, in order to analyse the effect of annual modulations in tidal amplitude on mixing. Incorporation of a third intermediate layer leads to a significant improvement in the model results, showing the necessity for a three layer circulation scheme when modelling biogeochemical processes in the Strait of Gibraltar. Pelagic processes are modelled using a simple Nutrient–Phytoplankton–Zooplankton (NPZ) model. The intense physical mixing and advection in the channel are the main influence on plankton dynamics in the area. It is found that residence times within the channel are so short that phytoplankton communities cannot grow appreciably during their transit. As a consequence, the use of a more sophisticated biogeochemical model does not lead to significant changes in the results obtained. According to the model, mixing over the Camarinal Sill causes an average of 16% of the out-flowing nutrients to be returned back to the Mediterranean. This fraction varies between 4% and 35% as a function of the tidal amplitude. The comparison of the model results with field data suggests that in order to obtain an accurate simulation of the plankton ecosystem dynamics in the strait, it is necessary to take into account the full horizontal flow, as recirculation and coast-channel interactions seems to be very important processes in explaining the biological patterns in the area.

Sea level values from a two-dimensional model of the Mediterranean Sea forced by atmospheric pressure and wind are used to estimate the barotropic flow through the Strait of Gibraltar for the period 1958–2001. The Mediterranean mean sea level derived from the model ranges between ±20 cm with a standard deviation of 5.5 cm and is correlated to the North Atlantic Oscillation (NAO) index. Thus NAO historical data and reconstructions are used to derive the Mediterranean Sea level variability from 1659 until 2001. The accuracy of the reconstruction is estimated in 2.7 cm for monthly mean values, 0.41 cm for annual mean values, and 0.22 cm for decadal mean values (0.48 cm for decadal winter mean sea level). The barotropic flow through the strait is computed from the model output as the time derivative of the total volume of the basin. During the period 1958–2001 the estimated daily flow ranges between ±2.7 Sv, with a standard deviation of 0.56 Sv. The dominant periodicities are in between 1 and 2 weeks. At these scales the model successfully reproduces previously published flow estimates based on current meter observations, which confirms that atmospheric pressure and wind dominate the intraseasonal variability of the flow. For the annual cycle the variability of the atmospherically induced flow is similar to the variability of the flow induced by the evaporation-precipitation (E-P) budget (±0.025 Sv), though absolute values of the first are about a third of the latter. At longer timescales the atmospheric contribution is much smaller than the E-P induced flow.

Sea level values from a two-dimensional model of the Mediterranean Sea forced by atmospheric pressure and wind are used to estimate the barotropic flow through the Strait of Gibraltar for the period 1958–2001. The Mediterranean mean sea level derived from the model ranges between ±20 cm with a standard deviation of 5.5 cm and is correlated to the North Atlantic Oscillation (NAO) index. Thus NAO historical data and reconstructions are used to derive the Mediterranean Sea level variability from 1659 until 2001. The accuracy of the reconstruction is estimated in 2.7 cm for monthly mean values, 0.41 cm for annual mean values, and 0.22 cm for decadal mean values (0.48 cm for decadal winter mean sea level). The barotropic flow through the strait is computed from the model output as the time derivative of the total volume of the basin. During the period 1958–2001 the estimated daily flow ranges between ±2.7 Sv, with a standard deviation of 0.56 Sv. The dominant periodicities are in between 1 and 2 weeks. At these scales the model successfully reproduces previously published flow estimates based on current meter observations, which confirms that atmospheric pressure and wind dominate the intraseasonal variability of the flow. For the annual cycle the variability of the atmospherically induced flow is similar to the variability of the flow induced by the evaporation-precipitation (E-P) budget (±0.025 Sv), though absolute values of the first are about a third of the latter. At longer timescales the atmospheric contribution is much smaller than the E-P induced flow.

Aquest article mostra el resultat de la col·laboració portada a terme durant els darrers anys entre grups d'enginyeria química, enginyeria ambiental i intel·ligència artificial. El treball se centra en el desenvolupament de tècniques per a la millora i supervisió de processos complexos, especialment del tractament biològic d'aigües residuals. L'experiència demostra que la millor opció requereix desenvolupar un sistema supervisor que combini i integri tècniques de control clàssic (controlador automàtic del nivell d'oxigen dissolt en el reactor biològic, ús de models descriptius del procés, etc.) amb sistemes basats en el coneixement (concretament sistemes experts i sistemes basats en casos). El present article descriu la complexitat de la gestió del procés de tractament de les aigües residuals, l'arquitectura integrada que es proposa i el desenvolupament i la construcció de cadascun dels mòduls d'aquesta proposta per a la implementació real a l'estació depuradora d'aigües residuals de Granollers. Finalment, es detallen alguns resultats del procés de validació del seu funcionament enfront de situacions quotidianes de la planta., This paper shows the result of years of work by a cooperative research group including chemical engineers, environmental scientists and computer scientists. This research has been focused on the development and implementation of new techniques for the optimisation of complex process management, mainly related to wastewater treatment plants (WWTP). The experience obtained indicates that the best approach is a Supervisory System that combines and integrates classical control of WWTP (automatic controller for maintaining a fixed dissolved oxygen level in the aeration tank, use of mathematical models to describe the process...) with the application of knowledge-based systems (mainly expert systems and case-based systems). The first part is an introduction to wastewater treatment processes and an explanation of the complexity of the management and control of such complex processes. The next section illustrates the architecture of the supervisory system and the work carried out to develop and build the expert system, the casebased system and the simulation model for implementation in a real plant (the Granollers WWTP). Finally, some results of the field validation phase of the Supervisory System when dealing with real situations in the plant are described.

To estimate the volume transport through the Strait of Gibraltar and to study the spatial structure of the time-variable flow, a varying number of current meter moorings were maintained at the eastern entrance of the strait between October 1994 and April 1998, and was complemented with intensive shipboard measurements during the European Union project Canary Island Azores Gibraltar Experiment (CANIGO). A tidal inverse model is used to merge these data sets in order to investigate the flow at the eastern entrance of the strait. The two-dimensional structure of the tidal flow was described by simple analytical functions. Harmonics with the seven most important tidal frequencies were used as temporal functions. With this model, the tidal currents can be predicted for any time and location at the eastern entrance of the strait, and more than 92% of the variance of the lower layer flow is explained. It was used to remove the tidal currents from the individual measurements and to calculate the mean flow through the strait from the residuals. Combined with a similar inverse model for determining the depth of the interface between Mediterranean and Atlantic water, the volume transport was estimated to be 0.81 ± 0.07 Sv for the upper layer and −0.76 ± 0.07 Sv for the lower layer. The correlation of the tidal currents and the fluctuations of the interface accounts for ∼7% of the transport at the eastern entrance.

To estimate the volume transport through the Strait of Gibraltar and to study the spatial structure of the time-variable flow, a varying number of current meter moorings were maintained at the eastern entrance of the strait between October 1994 and April 1998, and was complemented with intensive shipboard measurements during the European Union project Canary Island Azores Gibraltar Experiment (CANIGO). A tidal inverse model is used to merge these data sets in order to investigate the flow at the eastern entrance of the strait. The two-dimensional structure of the tidal flow was described by simple analytical functions. Harmonics with the seven most important tidal frequencies were used as temporal functions. With this model, the tidal currents can be predicted for any time and location at the eastern entrance of the strait, and more than 92% of the variance of the lower layer flow is explained. It was used to remove the tidal currents from the individual measurements and to calculate the mean flow through the strait from the residuals. Combined with a similar inverse model for determining the depth of the interface between Mediterranean and Atlantic water, the volume transport was estimated to be 0.81 ± 0.07 Sv for the upper layer and −0.76 ± 0.07 Sv for the lower layer. The correlation of the tidal currents and the fluctuations of the interface accounts for ∼7% of the transport at the eastern entrance.

To estimate the volume transport through the Strait of Gibraltar and to study the spatial structure of the time-variable flow, a varying number of current meter moorings were maintained at the eastern entrance of the strait between October 1994 and April 1998, and was complemented with intensive shipboard measurements during the European Union project Canary Island Azores Gibraltar Experiment (CANIGO). A tidal inverse model is used to merge these data sets in order to investigate the flow at the eastern entrance of the strait. The two-dimensional structure of the tidal flow was described by simple analytical functions. Harmonics with the seven most important tidal frequencies were used as temporal functions. With this model, the tidal currents can be predicted for any time and location at the eastern entrance of the strait, and more than 92% of the variance of the lower layer flow is explained. It was used to remove the tidal currents from the individual measurements and to calculate the mean flow through the strait from the residuals. Combined with a similar inverse model for determining the depth of the interface between Mediterranean and Atlantic water, the volume transport was estimated to be 0.81 ± 0.07 Sv for the upper layer and −0.76 ± 0.07 Sv for the lower layer. The correlation of the tidal currents and the fluctuations of the interface accounts for ∼7% of the transport at the eastern entrance.

From October 1995 to April 1996, three mooring lines were deployed at the eastern entrance of the Strait of Gibraltar. The spatial coverage of the mooring array allows for a good description of the tides. They exhibit a dominant semidiurnal nature and a noticeable baroclinic structure that matches the one of the mean exchange. Tidal currents in the upper layer are irregular and usually too weak to reverse the mean upper layer how that keeps on flowing east. Lower layer flow reverses with semidiurnal periodicity because of the smallness of the mean flow and the appreciable amplitude of the regular semidiurnal oscillation of tidal currents in this layer. Tidal transports can be satisfactorily compared with previous estimates of Bryden et al. [1994] if we allow for strong internal divergences associated with the internal tide. No significant eddy flux of water transport (tidal rectification) is observed at the eastern section, contrary to the almost 50% of the total layer transport found by Bryden et al. [1994] in Camarinal Sill section. Time-dependent hydraulic theory provides a good scenario for interpreting these two independent sets of observations despite the fact that the composite Froude number does not reach the critical values predicted in the hydraulic models most of the time.