Combined Effects of the North Atlantic Oscillation and the Arctic Oscillation on Sea Surface Temperature in the Alborán Sea

We explored the possible effects of the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) on interannual sea surface temperature (SST) variations in the Albora´n Sea, both separately and combined. The probability of observing mean annual SST values higher than average was related to NAO and AO values of the previous year. The effect of NAO on SST was negative, while that of AO was positive. The pure effects of NAO and AO on SST are obscuring each other, due to the positive correlation between them. When decomposing SST, NAO and AO in seasonal values, we found that variation in mean annual SST and mean winter SST was significantly related to the mean autumn NAO of the previous year, while mean summer SST was related to mean autumn AO of the previous year. The one year delay in the effect of the NAO and AO on the SST could be partially related to the amount of accumulated snow, as we found a significant correlation between the total snow in the North Albora´n watershed for a year with the annual average SST of the subsequent year. A positive AO implies a colder atmosphere in the Polar Regions, which could favour occasional cold waves over the Iberian Peninsula which, when coupled with precipitations favoured by a negative NAO, may result in snow precipitation. This snow may be accumulated in the high peaks and melt down in spring-summer of the following year, which consequently increases the runoff of freshwater to the sea, which in turn causes a diminution of sea surface salinity and density, and blocks the local upwelling of colder water, resulting in a higher SST.CGL2009-11316 (Ministerio de Ciencia e Innovación, Spain, and FEDER

Adsorption of landfill leachates onto activated carbon: Equilibrium and kinetics

The adsorption of stabilized leachates generated in a municipal landfill onto three commercial activated carbons has been investigated. Norit 0.8, Chemviron AQ40 and Picacarb 1240 have been used as adsorbents. Equilibrium experiments have been conducted to obtain the experimental isotherm profiles. Isotherms have been plotted based on the adsorption of general parameters, for instance chemical oxygen demand, total carbon, absorption at 410 nm and absorption at 254 nm. Different literature models and error functions have been used to adequately fit the experimental data. As a rule of thumb, three-parameter models do adjust experimental results better than two-parameter models. Norit 0.8 shows better adsorption characteristics than the rest of activated carbons, both in terms of contaminant level reduction of per unit mass of absorbent and in terms of the process kinetics

Fenton-like oxidation of landfill leachate

The treatment of stabilized leachates by means of Fenton's like reagent [Fe(III)-H2O2] has been studied. It has been demonstrated that the oxidation state of the catalyst does not influence the efficacy of the process in terms of chemical oxygen demand depletion profiles. The abrupt increase in temperature experienced in oxidation experiments involves a wastage of hydrogen peroxide diminishing the fraction of this reagent addressed at removing COD. If temperature is kept constant, the hydrogen peroxide uptake is 10 mg of H2O2 consumed per mg of COD abated (from 15 to 30°C). Working temperatures above 30°C does not lead to additional COD conversion, contrarily, the percentage of wasted H2O2 is increased. A rough economic analysis of the process indicates that this treatment can be a suitable alternative to deal with this type of effluents

Study of different integrated physical-chemical + adsorption processes for landfill leachate remediation

Some integrated processes to deal with landfill leachates have been investigated and their efficiencies expressed in terms of chemical oxygen demand (COD) removal. The systems tested were the result of different combinations of the following single stages: acidic pH shift (elimination of humic substances), ozonation (O3), coagulation-flocculation with Fe(III) salts, Fenton's oxidation (Fe(III) + H2O2), wet air oxidation (with or without radical promoters), and adsorption onto activated carbon (commercial Norit 0.8 powdered activated carbon). COD removals obtained ranged in the interval of 80-96% for initial COD values close to 11000 mg L-1. None of the processes tested reduced the COD levels sufficiently to allow direct discharge; however, the ratio biochemical oxygen demand (BOD/COD was significantly increased (up to 1000% in some cases, i.e., from 0.1 to values above 1.0). Total carbon reduction achieved ranged from 60 to 94%, while complete decolorization (measured as the absorbance at 410 nm) was obtained in practically all the combinations investigate

Stabilized leachates: sequential coagulation–flocculation + chemical oxidation process

The combined sedimentation-chemical oxidation treatment of medium-stabilized landfill leachates has been investigated. The sequence of stages implemented was: (a) coagulation–flocculation by pH decrease (pH 2) to acidic conditions (COD removal ≈ 25% related to COD0 ≈ 7500 ppm); (b) coagulation–flocculation by Fe(III) addition (0.01 M) at pH 3.5 (COD removal ≈ 40% related to COD of supernatant after step (a); (c) Fenton (Fe(III) = 0.01 M; H2O2 = 1.0 M) oxidation (COD removal ≈ 80% related to COD of supernatant after step (a); and (d) coagulation–flocculation of Fenton’s effluent at pH 3.5 (COD removal ≈ 90% related to COD of supernatant after step (a). The use of Kynch theory allows for the design of clarifiers based on the amount of solids fed. For a general example of 1000 m3 day−1 of a feeding stream, clarifier area values of 286, 111 and 231 m2 were calculated for compacting indices of 3.7, 2.67 and 2.83 corresponding to the first, second and third consecutive sedimentation processes, respectively, (steps (a), (b) and (d))

Relationship between vestibular hair cell loss and deficits in two anti-gravity reflexes in the rat.

The tail-lift reflex and the air-righting reflex in rats are anti-gravity reflexes that depend on vestibular function. To begin identifying their cellular basis, this study examined the relationship between reflex loss and the graded lesions caused in the vestibular sensory epithelia by varying doses of an ototoxic compound. After ototoxic exposure, we recorded these reflexes using high speed video. The movies were used to obtain objective measures of the reflexes: the minimum angle formed by the nose, the back of the neck and the base of the tail during the tail-lift maneuver and the time to right in the air-righting test. The vestibular sensory epithelia were then collected from the rats and used to estimate the loss of type I (HCI), type II (HCII) and all hair cells (HC) in both central and peripheral parts of the crista, utricle, and saccule. As expected, tail-lift angles decreased, and air-righting times increased, while the numbers of HCs remaining in the epithelia decreased in a dose-dependent manner. The results demonstrated greater sensitivity of HCI compared to HCII to the IDPN ototoxicity, as well as a relative resiliency of the saccule compared to the crista and utricle. Comparing the functional measures with the cell counts, we observed that loss of the tail-lift reflex associates better with HCI than with HCII loss. In contrast, most HCI in the crista and utricle were lost before air-righting times increased. These data suggest that these reflexes depend on the function of non-identical populations of vestibular HCs

Geochemical characterisation and modelling of the Luchon hydrothermal system (Central Pyrenees, France) and lessons learnt for the use of geochemical modelling techniques in granite-hosted alkaline thermal waters

Alkaline hydrothermal systems hosted in granitic rocks have been extensively investigated as natural analogues for radioactive waste disposal and for the geological storage of CO2. Thereby, their geochemical characterisation provides useful information for the long-term performance assessment predictions. The geochemical modelling of one of these alkaline hydrothermal systems has been performed in Luchon (France), together with the application of different geothermometrical techniques to determine the temperature, pH and mineral equilibrium conditions at depth. The modelling results show that the main processes controlling the hydrogeochemical evolution of this system are: (1) the mixing between deep thermal and cold surface waters, (2) the conductive cooling and (3) the external input of CO2. Other important results are that the most alkaline thermal waters are characterised by a high pH-buffering capacity during the mixing processes, and that the high pH values that characterise these thermal waters are not only inherited from the deep reservoir but strongly enhanced by conductive cooling. The reservoir temperature predicted by the geothermometrical modelling is in the range of 117 ± 8 °C, in good agreement with the temperatures ranging from 108 to 133 °C predicted by the classical geothermometers. The results of these calculations indicate as well that the thermal solutions have reached equilibrium with quartz, albite, potassium feldspar, zoisite and prehnite, and that a re-equilibirum with kaolinite and calcite is reached during their ascent to the surface. Another important outcome is that the precipitation of calcite in the deep reservoir could take place as a CO2 mineral trapping mechanism in similar systems. Further, the sharp influence of the surface waters on the deep thermal waters reveals a high susceptibility of the system to potential contamination processes

CMOS Receiver Front-End Architecture for High-Speed SI-POF Links

This works presents a new CMOS analog front-end for short-reach high-speed optical communications which compensates the limited bandwidth of POF channels and is suitable for the required large area photodetectorf The proposed pseudo-differential architecture, formed by a preamplifier and an equalizer, has been designed in a standard 0.18-μm CMOS process with a 1-V supply voltage targeting gigabit transmission for NRZ modulation. The preamplifier is based on the flipped voltage follower stage to attain a very low input resistance in order to handle the large phodiode capacitance (3 pF). The equalizer can adjust the high-frequency boosting and the gain, to compensate for the variation of the characteristics of the channel due to length of the fiber, connections, etc. causing subtantial changes of the fiber bandwidth. Reliable electrical models are employed for a Mitsubishi GH SI-POF with 10-m to 50-m length and for a S5972 silicon photodiode from Hamamatsu suitable for such a fiber due to its large diameter (0.8 mm) and responsivity at 650 nm (0.44A/W). The bandwidth of the received signal can be enhanced from 100 MHz to 1.4 GHz and from 300 MHz to 1.4 GHz for a 50-m and 10-m POF respectively. The proposed circuit shows a transimpedance of 41.5 dBΩ while the theoretical sensitivity from noise performance is below -7.5 dBm with a BER = 10-12. The power consumption is below 16 mW from 1-V supply voltage. In conclusion it targets 1.25 Gbps through a 1-mm SI-POF up to 50-m length with a commercial Si PIN photodiode

Bioequivalence studies with anti-TNF biosimilars

Introduction: Biosimilars, as defined by the European Medicines Agency, have been used in Europe since 2006. The landscape was considerably expanded when the first biosimilar of a monoclonal was approved and introduced in the European market. CT-P13 was developed by Celltrion as an infliximab biosimilar in 2013, not without controversy. As these complex molecules cannot be completely identical, some experts, clinicians, and even patients were skeptical regarding the real bioequivalence of the drugs. Currently, several new infliximab and adalimumab biosimilars are available or will reach the market in a few months. Areas covered: Our goal is to review, mainly from a clinical perspective, the available evidence for bioequivalence of anti-TNF biosimilars. We aim to take into account not only preclinical studies, mostly done for regulatory issues, but also data from clinical studies. Expert opinion: We can conclude that bioequivalence with originator is well demonstrated in those drugs which have followed European Medicines Agency regulatory pathways. Switching from originator to biosimilar appears safe for all indications. However, there are few data available for switching from one biosimilar to another, or for complete interchangeability. Prospective studies and strict pharmacovigilance are recommended