A modelling approach to evaluate the present and future effectiveness of hypolimnetic withdrawal for the restoration of eutrophic Lake Varese (Northern Italy).

Hypolimnetic withdrawal has been applied as a restoration measure in lakes subject to eutrophication together with external load reduction, to decrease internal load by removing limiting nutrient phosphorus (P) from anoxic deep waters and contributing to the unloading of bottom sediments from previously deposited nutrients and organic matter. The aim of this study is to evaluate the effect of hypolimnetic withdrawal on Lake Varese, a 24 m-deep and 14.8 km2-large subalpine lake in North-Western Italy. The lake suffered from extended eutrophication in the second half of the 20th century due to uncontrolled delivery of untreated urban sewage. Several restoration measures have been implemented during the years, including hypolimnetic withdrawal. In 2019, a cooperative programme for the protection and management of the lake and its surroundings was launched, establishing a systematic annual hypolimnetic withdrawal in the stratified season since 2020. In this research, we calibrated a one-dimensional (1D) coupled ecological-hydrodynamic model (General Lake Model/Aquatic EcoDynamics - GLM/AED2) of Lake Varese with data surveyed in the lake in 2019-2021. Model simulations of the period 2020-2021 with and without the performed withdrawal proved the effectiveness of this measure on hypolimnetic P concentration reduction. Then, future simulations of 2023-2085 were carried out to predict the future efficiency of hypolimnetic withdrawal and of reductions in external nutrient loads under climate change scenarios. Results show that the prescribed withdrawal increases hypolimnetic temperatures. This effect, coupled with thermocline deepening due to global warming, will possibly lead to decreasing water mass stability in autumn and shorter stratification in the moderately deep Lake Varese, with an eventual decrease of P concentrations in the water column. The future effectiveness of hypolimnetic withdrawal is further discussed considering the possible role of dry periods.

Cerebral Outflow Discrepancies in Recurrent Benign Paroxysmal Positional Vertigo: Focus on Ultrasonographic Examination.

This prospective pilot study aimed to evaluate whether cerebral inflow and outflow abnormalities assessed by ultrasonographic examination could be associated with recurrent benign paroxysmal positional vertigo (BPPV). Twenty-four patients with recurrent BPPV, affected by at least two episodes, and diagnosed according to American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria, evaluated at our University Hospital, between 1 February 2020 and 30 November 2021, have been included. At the ultrasonographic examination, 22 of 24 patients (92%) reported one or more alterations of the extracranial venous circulation, among those considered for the diagnosis of chronic cerebrospinal venous insufficiency (CCSVI), although none of the studied patients were found to have alterations in the arterial circulation. The present study confirms the presence of alterations of the extracranial venous circulation in recurrent BPPV; these anomalies (such as stenosis, blockages or regurgitation of flow, or abnormal valves, as per the CCSVI) could cause a disruption in the venous inner ear drainage, hampering the inner ear microcirculation and then possibly causing recurrent otolith detachment.

DNA sequence and taxonomic gap analyses to quantify the coverage of aquatic cyanobacteria and eukaryotic microalgae in reference databases: Results of a survey in the Alpine region.

The taxonomic identification of organisms based on the amplification of specific genetic markers (metabarcoding) implicitly requires adequate discriminatory information and taxonomic coverage of environmental DNA sequences in taxonomic databases. These requirements were quantitatively examined by comparing the determination of cyanobacteria and microalgae obtained by metabarcoding and light microscopy. We used planktic and biofilm samples collected in 37 lakes and 22 rivers across the Alpine region. We focused on two of the most used and best represented genetic markers in the reference databases, namely the 16S rRNA and 18S rRNA genes. A sequence gap analysis using blastn showed that, in the identity range of 99-100%, approximately 30% (plankton) and 60% (biofilm) of the sequences did not find any close counterpart in the reference databases (NCBI GenBank). Similarly, a taxonomic gap analysis showed that approximately 50% of the cyanobacterial and eukaryotic microalgal species identified by light microscopy were not represented in the reference databases. In both cases, the magnitude of the gaps differed between the major taxonomic groups. Even considering the species determined under the microscope and represented in the reference databases, 22% and 26% were still not included in the results obtained by the blastn at percentage levels of identity ≥95% and ≥97%, respectively. The main causes were the absence of matching sequences due to amplification and/or sequencing failure and potential misidentification in the microscopy step. Our results quantitatively demonstrated that in metabarcoding the main obstacles in the classification of 16S rRNA and 18S rRNA sequences and interpretation of high-throughput sequencing biomonitoring data were due to the existence of important gaps in the taxonomic completeness of the reference databases and the short length of reads. The study focused on the Alpine region, but the extent of the gaps could be much greater in other less investigated geographic areas.

Generation and dispersion of chemical and biological gradients in a large-deep multi-basin lake (Lake Como, north Italy): The joint effect of external drivers and internal wave motions.

The formation of chemical and biological heterogeneity in lakes can be favored by physical and morphometric constrains. This study describes the results of four whole-lake field campaigns carried out in Lake Como (north Italy) during thermal stratification. The aim was to analyze the distribution of chemical-biological variables in a multi-basin lake as a result of internal and external physical drivers and constrains. Lake Como has a y-like shape encompassing three main sub-basins: northern, south-eastern, and south-western. Field data underlined: the presence of chemical-biological gradients between the south-western basin and the rest of the lake and the propagation of a fresher water-plume (formed by the two main northern inflows) into the northern basin and then into the south-western closed arm. The use of a three-dimensional hydrodynamic model showed a periodic movement of this plume that tends to enter the south-western basin first and then to return toward north, moving forward and back through the junction of the three arms. The entrance into the eastern basin, instead, occurs only secondarily. Wavelet transform analysis revealed common periodicity between the plume movement and the action of different external and internal lake-stressors, including: the discharge of the main inflow (period centered at 1, 3.3, and 6.5 day), the wind intensity (0.5 and 1 day) and the two main basin-scale internal wave motions: (3.3 day and 7.1 day). The periodic movement of the fresher water-plume enhances the water exchange and reduces the chemical-biological gradients between the western closed basin and the main lake, playing a crucial role in distributing both inorganic and organic materials at the lake basin-scale.

Plankton dynamics across the freshwater, transitional and marine research sites of the LTER-Italy Network. Patterns, fluctuations, drivers.

A first synoptic and trans-domain overview of plankton dynamics was conducted across the aquatic sites belonging to the Italian Long-Term Ecological Research Network (LTER-Italy). Based on published studies, checked and complemented with unpublished information, we investigated phytoplankton and zooplankton annual dynamics and long-term changes across domains: from the large subalpine lakes to mountain lakes and artificial lakes, from lagoons to marine coastal ecosystems. This study permitted identifying common and unique environmental drivers and ecological functional processes controlling seasonal and long-term temporal course. The most relevant patterns of plankton seasonal succession were revealed, showing that the driving factors were nutrient availability, stratification regime, and freshwater inflow. Phytoplankton and mesozooplankton displayed a wide interannual variability at most sites. Unidirectional or linear long-term trends were rarely detected but all sites were impacted across the years by at least one, but in many case several major stressor(s): nutrient inputs, meteo-climatic variability at the local and regional scale, and direct human activities at specific sites. Different climatic and anthropic forcings frequently co-occurred, whereby the responses of plankton communities were the result of this environmental complexity. Overall, the LTER investigations are providing an unparalleled framework of knowledge to evaluate changes in the aquatic pelagic systems and management options.

Are physicians aware enough of patient radiation protection? Results from a survey among physicians of Pavia District- Italy.

BACKGROUND: Radiological practices are the first anthropic sources of ionizing radiation exposure of the population. However, a review of recent publications underlines inadequate doctors' knowledge about doses imparted in medical practices and about patient protection that might explain unnecessary radiological prescriptions. We investigated the knowledge of the physicians of Pavia District (Italy) on the risk of radiation exposure. METHODS: A cross sectional study was performed involving the Medical Association of Pavia District. Data were collected with a self-administered questionnaire, available on-line with private login and password. RESULTS: Four hundred nineteen physicians fulfilled the questionnaire; 48% of participants reported training about radiation protection. The average percentage of correct answers on the knowledge on ionizing radiation was 62.29%, with a significantly higher result between radiologist. Around 5 and 13% of the responders do not know that, respectively, ultrasonography and magnetic resonance do not expose patients to ionizing radiations. Only 5% of the physicians properly identified the cancer risk rate associated to abdomen computed tomography. CONCLUSIONS: The findings show a quite good level of the general knowledge about ionizing radiations, higher that reported in literature. Nevertheless, we believe the usefulness of training on the risk linked to radiation exposure in medicine for physicians employed in every area.

Warming trends of perialpine lakes from homogenised time series of historical satellite and in-situ data.

The availability of more than thirty years of historical satellite data is a valuable source which could be used as an alternative to the sparse in-situ data. We developed a new homogenised time series of daily day time Lake Surface Water Temperature (LSWT) over the last thirty years (1986-2015) at a spatial resolution of 1km from thirteen polar orbiting satellites. The new homogenisation procedure implemented in this study corrects for the different acquisition times of the satellites standardizing the derived LSWT to 12:00 UTC. In this study, we developed new time series of LSWT for five large lakes in Italy and evaluated the product with in-situ data from the respective lakes. Furthermore, we estimated the long-term annual and summer trends, the temporal coherence of mean LSWT between the lakes, and studied the intra-annual variations and long-term trends from the newly developed LSWT time series. We found a regional warming trend at a rate of 0.017°Cyr-1 annually and 0.032°Cyr-1 during summer. Mean annual and summer LSWT temporal patterns in these lakes were found to be highly coherent. Amidst the reported rapid warming of lakes globally, it is important to understand the long-term variations of surface temperature at a regional scale. This study contributes a new method to derive long-term accurate LSWT for lakes with sparse in-situ data thereby facilitating understanding of regional level changes in lake's surface temperature.

Aortic perforation due to cardiac resynchronisation therapy defibrillator lead placement: Case report and medicolegal considerations.

A 45-year-old woman with dilated cardiomyopathy was admitted for the upgrade of a previously implanted pacemaker. Echocardiography showed intraventricular dyssynchrony and a low ejection fraction (0.35). Treatment with a cardiac resynchronization therapy defibrillator (CRT-D) was selected and the device was implanted. CRT-D interrogation revealed proper function. Following procedure termination, the patient went into cardiac arrest and died despite resuscitation attempts. An autopsy revealed that the medial aspect of the right atrium was pierced by an active lead and that the aorta had a deep lesion, 2 mm in length, on its lateral aspect. We explain the probable pathogenesis of this patient׳s death.

Recent trends in chloride and sodium concentrations in the deep subalpine lakes (Northern Italy).

A growing concern exists about the effects of chloride (Cl) on freshwater systems. Increasing Cl concentrations have been observed in the last few decades in several rivers and lakes, mainly in northern countries. In Italy, present levels and temporal changes of sodium (Na) and Cl in water bodies have rarely been assessed. Based on long-term data for the lakes of the subalpine district in Italy (Maggiore, Lugano, Como, Iseo, Garda), we analyzed trends affecting Cl and Na concentrations during the last 25 years, with the aim of identifying temporal changes and assessing possible causes. An in-depth analysis is presented for Lake Maggiore. Positive temporal Na and Cl trends were evident in all studied lakes, with the trends increasing since early 2000s. Data for Lake Maggiore tributaries showed a clear seasonality (higher values in winter and early spring). The NaCl used as road de-icing agent, together with Cl discharge from wastewater treatment plants, were identified as the main causes for the observed trends. Chloride concentrations in the lakes are below the threshold limit for reduced water quality and below concentrations known to harm aquatic biota. However, considering the relevance of deep subalpine lakes, representing almost 80% of the total freshwater volume in Italy, these trends indicate an important chemical change, which warrants further analysis.

[Information and consensus for an appropriate medical-legal management of nosocomial infections, also in the light of the recommendations of the Joint Commission International Accreditation and the directions of the Supreme Court]. / Informazione e consenso ai fini di un'appropriata gestione medico-legale delle infezioni nosocomiali, anche alla luce delle indicazioni della Joint Commission International Accreditation e degli indirizzi della Cassazione.

The author, underlined the general importance of the information towards the persons who receive hospital assistance and recalled also the historical bases and the international inquiry upon this matter, precises the reasons that need particular information procedure regarding the hospital infections, because the problems raised by these infections and the safety measures against them request to involve also all people entering the hospital as visitors. On the basis of some specific items fixed by the Joint Commission International Accreditation in order of the duties of the hospital directions, well applicable on this matter, the author suggests that the material impossibility to zeroing occurrence of the hospital infections, in case of litigations between hospitals and patients needs alternative dispute solutions. In this respect the author mentions the opportunities created by law in France and, very recently, in Italy too. Finally, the author points out the pretentions of the Italian Supreme Court about the completeness and the precision that must caractherize the procedure of informed consent about all risks of every medical activity, otherwise the liability of the hospitals and the members of their care staffs is quite presumed--even from the point of view of the penal aforethought--while the medical performance has been proper.

Defining chlorophyll-a reference conditions in European lakes.

The concept of "reference conditions" describes the benchmark against which current conditions are compared when assessing the status of water bodies. In this paper we focus on the establishment of reference conditions for European lakes according to a phytoplankton biomass indicator--the concentration of chlorophyll-a. A mostly spatial approach (selection of existing lakes with no or minor human impact) was used to set the reference conditions for chlorophyll-a values, supplemented by historical data, paleolimnological investigations and modelling. The work resulted in definition of reference conditions and the boundary between "high" and "good" status for 15 main lake types and five ecoregions of Europe: Alpine, Atlantic, Central/Baltic, Mediterranean, and Northern. Additionally, empirical models were developed for estimating site-specific reference chlorophyll-a concentrations from a set of potential predictor variables. The results were recently formulated into the EU legislation, marking the first attempt in international water policy to move from chemical quality standards to ecological quality targets.