Seawater physics and chemistry along the Med-SHIP transects in the Mediterranean Sea in 2016

The Mediterranean Sea has been sampled irregularly by research vessels in the past, mostly by national expeditions in regional waters. To monitor the hydrographic, biogeochemical and circulation changes in the Mediterranean Sea, a systematic repeat oceanographic survey programme called Med-SHIP was recommended by the Mediterranean Science Commission (CIESM) in 2011, as part of the Global Ocean Ship-based Hydrographic Investigations Program (GO-SHIP). Med-SHIP consists of zonal and meridional surveys with different frequencies, where comprehensive physical and biogeochemical properties are measured with the highest international standards. The first zonal survey was done in 2011 and repeated in 2018. In addition, a network of meridional (and other key) hydrographic sections were designed: the first cycle of these sections was completed in 2016, with three cruises funded by the EU project EUROFLEETS2. This paper presents the physical and chemical data of the meridional and key transects in the Western and Eastern Mediterranean Sea collected during those cruises.

Short-term impact assessment of ocean liming: A copepod exposure test

Ocean liming (OL) is a potential carbon dioxide removal (CDR) method that aims to increase the ocean's capacity to absorb atmospheric CO2 by adding hydrated lime to the surface ocean. Modeling studies indicate that OL may cause temporary pH spikes lasting several minutes, depending on the lime sparging rate. Little is known about the short-term effects of these spikes on marine organisms. Aim of the present study is to investigate these effects on the copepod Acartia tonsa. Copepods were exposed to different pH conditions (9, 10, 11, 12) by dosing different hydrated lime solutions. Copepod mortality, movements, and behavior were recorded. At pH 9 for short exposure times (<6 h), no negative effects were observed indicating a potential tolerable threshold for OL applications. At longer exposure times (>6 h) and pH higher than 9, negative effects (mortality and sublethal effects) were found significantly higher than in the control.

Evidence of Covid-19 lockdown effects on riverine dissolved organic matter dynamics provides a proof-of-concept for needed regulations of anthropogenic emissions

The fast spread of SARS-CoV-2 virus in Italy resulted in a 3-months lockdown of the entire country. During this period, the effect of the relieved anthropogenic activities on the environment was plainly clear all over the country. Herein, we provide the first evidence of the lockdown effects on riverine dissolved organic matter (DOM) dynamics. The strong reduction in anthropogenic activities resulted in a marked decrease in dissolved organic carbon (DOC) concentration in the Arno River (-44%) and the coastal area affected by its input (-15%), compared to previous conditions. The DOM optical properties (absorption and fluorescence) showed a change in its quality, with a shift toward smaller and less aromatic molecules during the lockdown. The reduced human activity and the consequent change in DOM dynamics affected the abundance and annual dynamics of heterotrophic prokaryotes. The results of this study highlight the extent to which DOM dynamics in small rivers is affected by secondary and tertiary human activities as well as the quite short time scales to return to the impacted conditions. Our work also supports the importance of long-term research to disentangle the effects of casual events from the natural variability.

Organic Copper Speciation by Anodic Stripping Voltammetry in Estuarine Waters With High Dissolved Organic Matter

The determination of copper (Cu) speciation and its bioavailability in natural waters is an important issue due to its specific role as an essential micronutrient but also a toxic element at elevated concentrations. Here, we report an improved anodic stripping voltammetry (ASV) method for organic Cu speciation, intended to eliminate the important problem of surface-active substances (SAS) interference on the voltammetric signal, hindering measurements in samples with high organic matter concentration. The method relies on the addition of nonionic surfactant Triton-X-100 (T-X-100) at a concentration of 1 mg L^-1. T-X-100 competitively inhibits the adsorption of SAS on the Hg electrode, consequently 1) diminishing SAS influence during the deposition step and 2) strongly improving the shape of the stripping Cu peak by eliminating the high background current due to the adsorbed SAS, making the extraction of Cu peak intensities much more convenient. Performed tests revealed that the addition of T-X-100, in the concentration used here, does not have any influence on the determination of Cu complexation parameters and thus is considered "interference-free." The method was tested using fulvic acid as a model of natural organic matter and applied for the determination of Cu speciation in samples collected in the Arno River estuary (Italy) (in spring and summer), characterized by a high dissolved organic carbon (DOC) concentration (up to 5.2 mgC L^-1) and anthropogenic Cu input during the tourist season (up to 48 nM of total dissolved Cu). In all the samples, two classes of ligands (denoted as L₁ and L₂) were determined in concentrations ranging from 3.5 ± 2.9 to 63 ± 4 nM eq Cu for L₁ and 17 ± 4 to 104 ± 7 nM eq Cu for L₂, with stability constants logK _Cu,1 = 9.6 ± 0.2-10.8 ± 0.6 and logK _Cu,2 = 8.2 ± 0.3-9.0 ± 0.3. Different linear relationships between DOC and total ligand concentrations between the two seasons suggest a higher abundance of organic ligands in the DOM pool in spring, which is linked to a higher input of terrestrial humic substances into the estuary. This implies that terrestrial humic substances represent a significant pool of Cu-binding ligands in the Arno River estuary.

Time resolved data unveils the complex DOM dynamics in a Mediterranean river

In this study, dissolved organic carbon (DOC) data and optical properties (absorbance and fluorescence) of DOM, weekly collected in the Arno River for 2 years, are used to investigate the main processes determining DOM temporal dynamics in a small Mediterranean river, with torrential hydrology and medium-high human impact, and to quantify the contribution of this river to Med Sea carbon budget. A clear seasonal cycle of DOM, with DOC values ranging between 170 and 490 μM, was observed. Optical properties indicates that DOM quality in the river is different depending on the season; terrestrial humic-like substances prevail in winter, when discharge and floods are the main drivers of DOM concentration and quality, whereas autochthonous protein-like substances prevail in spring and summer, when biological processes dominate. Our results provide a robust estimate of the DOC flux to the Med Sea (9.6 · 10⁹ g DOC yr^-1) and of its range of variability (12.95 · 10⁹-5.12 · 10⁹ g DOC yr^-1). The 80% of this flux was generally delivered during autumn/winter with significant amounts ascribed to single flood events (up to 26% in 2014). This study, by providing a rich dataset on water quantity and quality and by quantifying the importance of the hydrological regime on DOC transport, represents an important step toward a quantitative modeling of the Arno River.

A rare iatrogenic association of syndrome of inappropriate secretion of antidiuretic hormone, neuroleptic malignant syndrome and rhabdomyolysis

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is considered the prevalent cause of hyponatremia in hospitalized patients. Neuroleptic malign syndrome (NMS) is an idiosyncratic drug reaction showing fever, dysautonomia and rigidity with increased levels of Creatinine-phosphokinase (CPK) dependent on leakage of muscle contents into the circulation and defined as rhabdomyolysis. Although different diagnostic criteria for NMS have been established, it should be recognized that atypical presentations occur, particularly during treatment with atypical antipsychotics. We here present a case report of a psychiatric patient affected by a SIADH complicated with NMS/rhabdomyolysis, induced by second-generation (atypical) antipsychotic drugs in combination with carbamazepine and promazine.

Localized herpes zoster infection: a rare cause of syndrome of inappropriate secretion of antidiuretic hormone

Hyponatremia is the most common electrolyte abnormality observed in clinical practice and syndrome of inappropriate secretion of antidiuretic hormone (SIADH) is diagnosed in nearly 40% of the hospitalized hyponatremic patients. We present a case report of herpes zoster infection causing a severe hyponatremia/hypokalemia. This rare association between SIADH and varicella-zoster virus infection is described in only few case in the literature. In our case report, the associated hypokalemia was not related to the use of diuretics but, probably, dependent on the frank serum hyposmolality able to induce an aldosterone release.

A MSFD complementary approach for the assessment of pressures, knowledge and data gaps in Southern European Seas: The PERSEUS experience

PERSEUS project aims to identify the most relevant pressures exerted on the ecosystems of the Southern European Seas (SES), highlighting knowledge and data gaps that endanger the achievement of SES Good Environmental Status (GES) as mandated by the Marine Strategy Framework Directive (MSFD). A complementary approach has been adopted, by a meta-analysis of existing literature on pressure/impact/knowledge gaps summarized in tables related to the MSFD descriptors, discriminating open waters from coastal areas. A comparative assessment of the Initial Assessments (IAs) for five SES countries has been also independently performed. The comparison between meta-analysis results and IAs shows similarities for coastal areas only. Major knowledge gaps have been detected for the biodiversity, marine food web, marine litter and underwater noise descriptors. The meta-analysis also allowed the identification of additional research themes targeting research topics that are requested to the achievement of GES.

Biophysical processes affecting DOM dynamics at the Arno river mouth (Tyrrhenian Sea)

Dissolved organic carbon (DOC) and optical properties (absorption and fluorescence) of chromophoric dissolved organic matter (CDOM) were measured in October 2012, at the Arno river mouth and in a coastal station close to it. The data reported indicates that the Arno river represents an important source of DOC and CDOM to this coastal area, with a total DOC flux of 11.23-12.04 · 10(9)g C · y(-1). Moving from the river to the sea, CDOM absorption and fluorescence decreased, while the spectral slope increased, suggesting a change in the molecular properties of CDOM. Mineralization experiments were carried out in order to investigate the main processes of DOM removal and/or transformation in riverine and coastal water. DOC removal rates were 20 μM · month(-1) in the river and 3 μM · month(-1) in the seawater, while CDOM was released during the first 30 days and removed in the following 40 days.

Enzymatic activities and prokaryotic abundance in relation to organic matter along a West-East Mediterranean transect (TRANSMED cruise)

The distribution of extracellular enzymatic activities (EEA) [leucine aminopeptidase (LAP), ß-glucosidase (GLU), alkaline phosphatase (AP)], as well as that of prokaryotic abundance (PA) and biomass (PB), dissolved organic carbon (DOC), particulate organic carbon and particulate total nitrogen (POC, PTN), was determined in the epi-, meso-, and bathypelagic waters of the Mediterranean Sea along a West-East transect and at one Atlantic station located outside the Strait of Gibraltar. This study represents a synoptical evaluation of the microbial metabolism during early summer. Decreasing trends with depth were observed for most of the parameters (PA, PB, AP, DOC, POC, PTN). Significant differences between the western and eastern basins of the Mediterranean Sea were found, displaying higher rates of LAP and GLU and lower C/N ratios more in the eastern than in the western areas. Conversely, in the epipelagic layer, PA and PB were found to be higher in the western than in the eastern basins. PB was significantly related to DOC concentration (all data, n = 145, r = 0.53, P < 0.01), while significant correlations of EEA with POC and PTN were found in the epipelagic layer, indicating an active response of microbial metabolism to organic substrates. Specific enzyme activities normalized to cell abundance pointed out high values of LAP and GLU in the bathypelagic layer, especially in the eastern basin, while cell-specific AP was high in the epi- and bathypelagic zone of the eastern basin indicating a rapid regeneration of inorganic P for both prokaryotes and phytoplankton needs. Low activity and abundance characterized the Atlantic station, while opposite trends of these parameters were observed along the Mediterranean transect, showing the uncoupling between abundance and activity data. In the east Mediterranean Sea, decomposition processes increased probably in response to mesoscale structures which lead to organic matter downwelling.

The bio-optical properties of CDOM as descriptor of lake stratification

Multivariate statistical techniques are used to demonstrate the fundamental role of CDOM optical properties in the description of water masses during the summer stratification of a deep lake. PC1 was linked with dissolved species and PC2 with suspended particles. In the first principal component that the role of CDOM bio-optical properties give a better description of the stratification of the Salto Lake with respect to temperature. The proposed multivariate approach can be used for the analysis of different stratified aquatic ecosystems in relation to interaction between bio-optical properties and stratification of the water body.

[Synchronous adenomas of the stomach and rectum with severe protein-losing syndrome]

The authors report a case of generalized edema with low colloidal osmotic pressure of plasma in an elderly man. After the exclusion of malnutrition and any myocadic, renal or hepatic involvement it has been shown that the physiopathogenetic mechanism is based on protein-losing enteropathy. Upper and lower endoscopy of the gastrointestinal tract reveals double synchronous villous adenomas of the rectum and stomach (the latter rare but often associated with the former). It is likely that these two lesions may play an important role in the development of "anasarca" but only complete reversal of symptoms after surgical excision of tumors would demonstrate the causative relationship. The study confirms two findings already observed in the literature. The first is the increased risk of villous adenoma malignant transformation, especially where rarely located, such as in the gastric site. The other depends upon the variety of villous adenoma symptomatology. The effects of low plasmatic protein levels are prominent in this case, but clinical manifestations range form insidious signs of occult bleeding, to frank diarrhea and/or rectal bleeding, up to unusual cases of secretory diarrhea with profound dehydration and hypokalemia or malabsorption.

Propafenone in Wolff-Parkinson-White syndrome at risk

We present our experience on the efficacy of propafenone in ten symptomatic patients with Wolff-Parkinson-White syndrome. The symptoms were dizziness in seven patients and syncope in three patients. While experiencing the symptoms, three of them presented an episode of atrial fibrillation, the shortest preexcited RR intervals being 140, 190, and 200 ms. In the other seven patients, the ECG was not recorded during the symptoms, but an episode of atrial fibrillation was subsequently induced by transesophageal pacing. The shortest preexcited RR intervals during induced atrial fibrillation were 180, 200, 270, 240, 230, 250, and 200 ms. Seven patients had both atrial fibrillation and supraventricular tachycardia. Propafenone (1-2 mg/kg) administered IV in only the patients with sustained atrial fibrillation (spontaneous in two and induced in one patient) prolonged the shortest preexcited RR intervals from 190, 200, and 180 ms to 340, 335, and 340 ms. In the other seven patients, propafenone was not given IV because atrial fibrillation rapidly deteriorated into ventricular fibrillation (one patient) or spontaneously reverted within 1-2 minutes to sinus rhythm (six patients). After oral propafenone, serial trans-esophageal pacing studies reinduced atrial fibrillation in 4 of 6 patients (the shortest preexcited RR intervals increased from 190, 180, 200, and 270 ms to 420, 320, 340, and 380 ms); only in one patient was it possible after propafenone to induce an atrial flutter without preexcitation. After propafenone therapy in 4 of 7 patients, supraventricular tachycardia was not inducible.(ABSTRACT TRUNCATED AT 250 WORDS)