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Abstract In alkaline freshwater systems, the apparent absence of carbon limitation to gross primary production (GPP) at low CO2 concentrations suggests that bicarbonates can support GPP. However, the contribution of bicarbonates to GPP has never been quantified in lakes along the seasons. To detect the origin of the inorganic carbon maintaining GPP, we analyze the daily stoichiometric ratios of CO2–O2 and alkalinity–O2 in a deep hardwater lake. Results show that aquatic primary production withdraws bicarbonate from the alkalinity pool for two‐thirds of the year. Alkalinity rather than CO2 is the dominant inorganic carbon source for GPP throughout the stratified period in both the littoral and pelagic environments. This study sheds light on the neglected role of alkalinity in the freshwater carbon cycle throughout an annual cycle.

Abstract Background Streptococcal infections are one of the main causes of fish disease. During the last decade, Streptococcus iniae has become one of the most important aquatic pathogens worldwide, causing high losses in marine and freshwater finfish. Clinical signs in farmed fish include loss of appetite, lethargy and grouping at the bottom of the tank. Gross changes comprise darkening of the skin and haemorrhage at the basis of fins and opercula. To date, S. iniae has been isolated from several wild and farmed fish species but never in the European eel (Anguilla anguilla). In Europe, eel production from aquaculture is around 4500 tonnes and Italy is the third largest producer. This communication represents the first report of an outbreak of S. iniae infection in European eels. Case presentation The outbreak occurred at an eel farm in northern Italy between May 2021 and September 2021. The outbreak caused about 2% mortality per month, resulting in the loss of about 10% of the farmed fish. The diseased eels showed apathy, lethargy, inactivity and inappetence. In July 2021, three eels were necropsied. Necropsy revealed skin and branchial hyperaemia, a few skin ulcers, and diffuse peritoneal congestion with a few haemorrhagic-like spot lesions. Swab samples for bacteriology were taken from the kidneys, liver, spleen, and brain. Additionally, four eels were opened and swap samples as above were taken. All the investigated eels were found dead. Bacteriological examination revealed growth of Streptococcus spp. from all samples. Identification of S. iniae was done by biochemical characterization, the API20STREP microsystem, 16S rDNA sequencing, and MALDI-TOF. Antimicrobial therapy (oxytetracycline and erythromycin) was ineffective. Conclusions This is the first report of S. iniae infection in the European eel. Although this may be an isolated outbreak, it is of concern due to the losses associated with this pathogen in fish worldwide and because the European eel is an endangered species. Due to the difficulties of controlling the disease with antimicrobials, it is advisable to plan other effective control measures, such as improving water quality and the environmental conditions, reducing fish density, improving biosecurity, and by using immunostimulants and, when possible, vaccines.

In the petrochemical industry, in order to control the final product quality over time and to detect potential plant failures, the amount of lab (off-line) analysis performed every day is very demanding in terms of resources and time. Hence, at/in-line monitoring can be an efficient solution to decrease chemical wastes and operators’ efforts and to perform a fast detection of deviations from normal operative conditions. Moving toward this implementation requires both installation of analytical sensors and the development of models capable to predict in real time the quality parameters of the polymers based on both process and analytical sensors. The primary aim of the current work has been the development of real time monitoring models by advanced chemometric tools for the prediction of a General Purpose PolyStyrene (GPPS) quality property, fusing Near Infrared (NIR) and process sensors data. In the plant considered, in addition to standard process sensors, along the GPPS production line, operating in continuous, two NIR probes are installed in-line. After the arrangement of the available data in different blocks, aiming at studying the specific contribution of the two types of sensors and of the main phases of the process, Multiblock-PLS (MB-PLS) method was employed to fuse the different blocks and to assess which were the most relevant sensors and plant phases for the prediction of the two quality parameters. Good prediction performances were achieved, allowing identifying the most significant data blocks for the GPPS quality prediction. Moreover, prediction errors obtained by models computed without considering blocks of data belonging to the final stages of the process were similar to those involving all the available data blocks. Therefore, a good real time assessment of the GPPS quality can be obtained even before the production is completed, which is very promising in view of minimizing the number of off-line laboratory analyses.

The influence of human activities on the role of inland waters in the global carbon (C) cycle is poorly constrained. In this study, we investigated the impact of human land use on the sources and biodegradation of dissolved organic matter (DOM) and its potential impact on bacterial respiration in 10 independent catchments of the Lake Geneva basin. Sites were selected along a gradient of human disturbance (agriculture and urbanization) and were visited twice during the winter high-flow period. Bacterial respiration and DOM bioavailability were measured in the laboratory through standardized dark bioassays, and the influence of human land uses on DOM sources, composition and reactivity was assessed from fluorescence spectroscopy. Bacterial respiration was higher in agro-urban streams but was related to a short-term bioreactive pool (0–6 d of incubation) of autochthonous origin, whose relative contribution to the total DOM pool increased with the degree of human disturbance. On the other hand, the degradation of a long-term (6–28 d) bioreactive pool related to terrestrial DOM was independent from the catchment land use and did not contribute substantially to aquatic bacterial respiration. From a greenhouse gas emission perspective, our results suggest that human activities may have a limited impact on the net C exchanges between inland waters and the atmosphere, as most CO2 fixed by aquatic producers in agro-urban streams is cycled back to the atmosphere after biomineralization. Although seasonal and longitudinal changes in DOM sources must be considered, the implications of our results likely apply more widely as a greater proportion of autochthonous-DOM signature is a common feature in human-impacted catchments. Yet, on a global scale, the influence of human activities remains to be determined given the large diversity of effects of agriculture and urbanization on freshwater DOM depending on the local environmental context.

The gas transfer velocity (k) is a major source of uncertainty when assessing the magnitude of lake gas exchange with the atmosphere. For the diversity of existing empirical and process-based k models, the transfer velocity increases with the level of turbulence near the air–water interface. However, predictions for k can vary by a factor of 2 among different models. Near-surface turbulence results from the action of wind shear, surface waves, and buoyancy-driven convection. Wind shear has long been identified as a key driver, but recent lake studies have shifted the focus towards the role of convection, particularly in small lakes. In large lakes, wind fetch can, however, be long enough to generate surface waves and contribute to enhance gas transfer, as widely recognised in oceanographic studies. Here, field values for gas transfer velocity were computed in a large hard-water lake, Lake Geneva, from CO2 fluxes measured with an automated (forced diffusion) flux chamber and CO2 partial pressure measured with high-frequency sensors. k estimates were compared to a set of reference limnological and oceanic k models. Our analysis reveals that accounting for surface waves generated during windy events significantly improves the accuracy of k estimates in this large lake. The improved k model is then used to compute k over a 1-year time period. Results show that episodic extreme events with surface waves (6 % occurrence, significant wave height > 0.4 m) can generate more than 20 % of annual cumulative k and more than 25 % of annual net CO2 fluxes in Lake Geneva. We conclude that for lakes whose fetch can exceed 15 km, k models need to integrate the effect of surface waves.

Abstract Electric fishing is an illegal hunting method, unfortunately widely used by poachers to paralyze fish and to catch many animals in a short time. In Italy, it is authorized only for scientific and conservative purposes. Between 2014 and 2018, the Ferrara section of the Experimental Zooprophylactic Institute of Lombardy and Emilia Romagna, Italy, received nine cases of potentially illegal electric fishing in Po river and its tributary rivers. Necropsies were performed following standard protocols and samples of different tissues were collected and examined using histochemical and immunohistochemical techniques. Gross lesions frequently observed were circulatory alteration phenomena (i.e. multi-organ hyperemia, hemorrhages and congestion, hemopericardium), also found histologically, in addition to multifocal degenerative and necrotic muscular processes that could be attributed to injuries from electric current, as already reported in literature. Immunohistochemical investigations confirmed degenerative and necrotic lesions with myoglobin depletion and a corresponding fibrinogen accumulation. Myoglobin globules were also detected in the renal parenchyma, as consequent of rhabdomyolysis. The results of this study allowed to correlate electric fishing to gross, histologic and immunohistochemical lesions, which together constitute a pathognomonic picture to be considered a reference standard in this type of illegal controversy.

Nodular gill disease (NGD) is an emerging condition associated with amoeba trophozoites in freshwater salmonid farms. However, unambiguous identification of the pathogens still must be achieved. This study aimed to identify the amoeba species involved in periodic NGD outbreaks in two rainbow trout (Oncorhynchus mykiss) farms in Northeastern Italy. During four episodes (February–April 2023), 88 fish were euthanized, and their gills were evaluated by macroscopic, microscopic and histopathological examination. The macroscopic and microscopic severity of the lesions and the degree of amoebae infestation were scored and statistically evaluated. One gill arch from each animal was put on non‐nutrient agar (NNA) Petri dishes for amoeba isolation, cultivation and subsequent identification with SSU rDNA sequencing. Histopathology confirmed moderate to severe lesions consistent with NGD and mild to moderate amoeba infestation. The presence of amoebae was significantly correlated with lesion severity. Light microscopy of cultured amoebae strains and SSU rDNA analysis revealed the presence of a previously characterized amoeba Naegleria sp. strain GERK and several new strains: two strains from Hartmannelidae, three vannelid amoebae from the genus Ripella and cercozoan amoeba Rosculus. Despite the uncertainty in NGD etiopathogenesis and amoebae pathogenic role, identifying known and new amoebae leans towards a possible multi‐aetiological origin. [ABSTRACT FROM AUTHOR]

Whiting events are massive calcite precipitation events turning hardwater lake waters to a milky turquoise color. Herein, we use a multispectral remote sensing approach to describe the spatial and temporal occurrences of whitings in Lake Geneva from 2013 to 2021. Landsat-8, Sentinel-2, and Sentinel-3 sensors are combined to derive the AreaBGR index and identify whitings using appropriate filters. 95% of the detected whitings are located in the northeastern part of the lake and occur in a highly reproducible environmental setting. An extended time series of whitings in the last 60 years is reconstructed from a random forest algorithm and analyzed through a Bayesian decomposition for annual and seasonal trends. The annual number of whiting days between 1958 and 2021 does not follow any particular monotonic trend. The inter-annual changes of whiting occurrences significantly correlate to the Western Mediterranean Oscillation Index. Spring whitings have increased since 2000 and significantly follow the Atlantic Multidecadal Oscillation index. Future climate change in the Mediterranean Sea and the Atlantic Ocean could induce more variable and earlier whiting events in Lake Geneva.

Petrochemical companies aim at assessing final product quality in real time, in order to rapidly deal with possible plant faults and to reduce chemical wastes and staff effort resulting from the many laboratory analyses performed every day. In order to answer these needs, the main purpose of the current work is to explore the feasibility of multiblock regression methods to build real-time monitoring models for the prediction of two quality properties of Acrylonitrile-Butadiene-Styrene (ABS) by fusing near-infrared (NIR) and process sensors data. Data come from a production plant, which operates continuously, and where four NIR probes are installed on-line, in addition to standard process sensors. Multiblock-PLS (MB-PLS) and Response-Oriented Sequential Alternation (ROSA) methods were here utilized to assess which of such sensors and plant areas were the most relevant for the quality parameters prediction. Several prediction models were constructed exploiting measurements provided by sensors active at different ABS production process stages. Both methods provided good prediction performances and permitted identification of the most relevant data blocks for the quality parameters’ prediction. Moreover, models built without considering recordings from the final stage of the process yielded prediction errors comparable to those involving all available data blocks. Thus, in principle, allowing final ABS quality to be estimated in real-time before the end of the process itself.

Nodular Gill Disease (NGD) is an emerging pathogenic condition that causes gill damage and mainly affects farmed freshwater fish, rainbow trout (Oncorhynchus mykiss) in particular, and this inevitably generates noticeable economic losses for the industry. The present study aimed to assess the prevalence of NGD in the Autonomous Province of Trento, a highly productive area located in Northeastern Italy, traditionally suited to rainbow trout production, and to identify possible risk factors for the introduction of this disease in trout farms. The necessary data were obtained through a questionnaire and the collection of fish samples. According to the data analysis, 42% of the investigated farms tested positive for NGD. The two possible risk factors identified for its introduction in farms are the presence of other diseases in the same farm (OR = 17.5; 95% CI = 2.7; 111.5) and having farms located 5 km upstream (OR = 24.8; 95% CI = 2.9; 211.1). These results highlight (i) a possible impairment of the immune system caused by other diseases as a predisposing factor to the manifestation of the pathology and (ii) the role of water in spreading pathogens. [ABSTRACT FROM AUTHOR]

In ice‐covered lakes, near‐bottom oxygen concentration decreases for most of the wintertime, sometimes down to the point that bottom waters become hypoxic. Studies insofar have reached divergent conclusions on whether climate change limits or reinforces the extent and duration of hypoxia under ice, raising the need for a comprehensive understanding of the drivers of the dissolved oxygen (DO) dynamics under lake ice. Using high‐temporal resolution time series of DO concentration and temperature across 14 mountain lakes, we showed that the duration of bottom hypoxia under ice varies from 0 to 236 d within lakes and among years. The variability of hypoxia duration was primarily explained by changes in the decay rate of DO above the lake bottom rather than by differences in DO concentration at the ice onset or in the ice‐cover duration. We observed that the DO decay rate was primarily linked to physical controls (i.e., deep‐water warming) rather than biogeochemical drivers (i.e., proxies for lake or catchment productivity). Using a simple numerical model, we provided a proof‐of‐concept that the near‐bed stratification can be the mechanism tying the DO decay rate to the sediment heat release under the ice. We ultimately showed that the DO decay rate and hypoxia duration are driven by the summer light climate, with faster oxygen decline found under the ice of clearer cryostratified alpine lakes. We derived a framework theorizing how the hypoxia duration might change under the ice of alpine lakes in a warmer climate. [ABSTRACT FROM AUTHOR]

In alkaline freshwater systems, the apparent absence of carbon limitation to gross primary production (GPP) at low CO2 concentrations suggests that bicarbonates can support GPP. However, the contribution of bicarbonates to GPP has never been quantified in lakes along the seasons. To detect the origin of the inorganic carbon maintaining GPP, we analyze the daily stoichiometric ratios of CO2–O2 and alkalinity–O2 in a deep hardwater lake. Results show that aquatic primary production withdraws bicarbonate from the alkalinity pool for two‐thirds of the year. Alkalinity rather than CO2 is the dominant inorganic carbon source for GPP throughout the stratified period in both the littoral and pelagic environments. This study sheds light on the neglected role of alkalinity in the freshwater carbon cycle throughout an annual cycle. [ABSTRACT FROM AUTHOR]

In the petrochemical industry, in order to control the final product quality over time and to detect potential plant failures, the amount of lab (off-line) analysis performed every day is very demanding in terms of resources and time. Hence, at/in-line monitoring can be an efficient solution to decrease chemical wastes and operators’ efforts and to perform a fast detection of deviations from normal operative conditions. Moving toward this implementation requires both installation of analytical sensors and the development of models capable to predict in real time the quality parameters of the polymers based on both process and analytical sensors. The primary aim of the current work has been the development of real time monitoring models by advanced chemometric tools for the prediction of a General Purpose PolyStyrene (GPPS) quality property, fusing Near Infrared (NIR) and process sensors data. In the plant considered, in addition to standard process sensors, along the GPPS production line, operating in continuous, two NIR probes are installed in-line. After the arrangement of the available data in different blocks, aiming at studying the specific contribution of the two types of sensors and of the main phases of the process, Multiblock-PLS (MB-PLS) method was employed to fuse the different blocks and to assess which were the most relevant sensors and plant phases for the prediction of the two quality parameters. Good prediction performances were achieved, allowing identifying the most significant data blocks for the GPPS quality prediction. Moreover, prediction errors obtained by models computed without considering blocks of data belonging to the final stages of the process were similar to those involving all the available data blocks. Therefore, a good real time assessment of the GPPS quality can be obtained even before the production is completed, which is very promising in view of minimizing the number of off-line laboratory analyses. [ABSTRACT FROM AUTHOR]

We report the case of a massive fetal cardiac rhabdomyoma recently occurred at our clinic. A woman at 23 weeks of gestational age was referred to our center for a fetal cardiac echogenic mass of 26 mm detected at the second-trimester screening ultrasound. During pregnancy, though, the mass progressively increased its dimensions until reaching 48 mm in diameter at 37 weeks of gestation. Fetal echoencephalography and brain magnetic resonance did not show any further fetal anomalies, but molecular genetic testing at amniocentesis revealed a heterozygotic missense variant of gene TSC2 associated with Tuberous Sclerosis. The mass was therefore most likely preferable to a single large rhabdomyoma of gradually increasing dimensions. The baby was delivered at term with a cesarean section. Because of the rhabdomyoma remarkable size and newborn ECG electrical alterations, postnatal therapies with Flecainide and Everolimus were started. Everolimus treatment led to a significant and progressive reduction in the cardiac mass volume. This case, therefore, shows the efficacy of what seems to be a promising treatment in pediatric patients with large rhabdomyomas. Rhabdomyomas may present with different features: most often they appear as multiple masses along the interventricular sept, but they may also appear as a single large thoracic mass. When a rhabdomyoma is suspected, genetic counseling is recommended. Both before and after birth, a multidisciplinary approach is useful to choose the appropriate therapy for the newborn. mTOR inhibitors therapies look like promising therapeutic approaches to stimulate the involution of rhabdomyomas. [ABSTRACT FROM AUTHOR]

Background Speckle tracking technology has been applied to assess ventricular deformation throughout the cardiac cycle. An electronic four dimensional probe that allows rapid acquisition of electronic spatio-temporal image correlation volumes (eSTIC) has been recently introduced. Objectives The aim of our study was to investigate whether e-STIC acquisition improves deformation analyses reproducibility. Study design We recruited fetuses between 20 and 40 weeks of gestation. We obtained a 2D video clip and an e-STIC volume of a four-chamber view. We focused on left ventricular global strain (LV-GS) and left ventricular ejection fraction (LV-FE). Intraobserver, interobserver and intermethod agreement were assessed by means of intraclass correlation coefficient (ICC) and illustrated by Bland-Altman plots. Systematic differences between measurements were assessed using a paired t-test. Results The mean difference between LV-GS values obtained with e-STIC and 2D analysis was −0.10 (95% CI −2.28, 2.08). No systematic differences were found between the two techniques for LV-GS values (p-value = .927). The mean difference between LV-FE values obtained with e-STIC and 2D analysis was 7.55 (95% CI 4.16, 10.95; p-value <.001). The inter-rater reliability of LV-GS was moderate-to-substantial for both e-STIC and 2D. The inter-rater reliability of LV-FE obtained via e-STIC was superior to that obtained via 2D analysis. The intra-rater reliability of LV-GS obtained with e-STIC was superior to that obtained with 2D analysis (ICC 0.857; 95% IC 0.761–0.917). The intra-rater reliability of LV-FE obtained via e-STIC was superior to that obtained via 2D analysis (ICC 0.647; IC 0.51–0.783). Conclusions e-STIC seems to be a better technique than 2D analysis for intra-rater reliability of LV-GS. 4D acquisition might improve intrinsic limitations of speckle tracking echocardiography. [ABSTRACT FROM AUTHOR]

Whiting events are massive calcite precipitation events turning hardwater lake waters to a milky turquoise color. Herein, we use a multispectral remote sensing approach to describe the spatial and temporal occurrences of whitings in Lake Geneva from 2013 to 2021. Landsat-8, Sentinel-2, and Sentinel-3 sensors are combined to derive the AreaBGR index and identify whitings using appropriate filters. 95% of the detected whitings are located in the northeastern part of the lake and occur in a highly reproducible environmental setting. An extended time series of whitings in the last 60 years is reconstructed from a random forest algorithm and analyzed through a Bayesian decomposition for annual and seasonal trends. The annual number of whiting days between 1958 and 2021 does not follow any particular monotonic trend. The inter-annual changes of whiting occurrences significantly correlate to the Western Mediterranean Oscillation Index. Spring whitings have increased since 2000 and significantly follow the Atlantic Multidecadal Oscillation index. Future climate change in the Mediterranean Sea and the Atlantic Ocean could induce more variable and earlier whiting events in Lake Geneva. [ABSTRACT FROM AUTHOR]

Coarctation of the aorta (CoA) is common and can lead to neonatal emergency. Despite its burden, antenatal detection of this condition remains inaccurate. To evaluate the diagnostic performance of fetal echocardiography and to design a scoring system for risk stratification of CoA in suspected cases. A retrospective cohort study. S. Orsola Hospital, Bologna, Italy. About 140 fetuses referred for suspected CoA to our tertiary center in a 9-year period. The following parameters were systematically obtained at fetal echocardiography: ventricular disproportion, great vessels asymmetry, transverse aortic arch hypoplasia, flow turbulence, and Z-scores of the ascending aorta and of the aortic isthmus. Associated anomalies were recorded, if present. When CoA was not confirmed at birth, neonates were followed up for 12 months to identify also a tardive onset of this condition. The primary outcome was the presence of COA after birth. 108 fetuses were eligible for the purpose of the study. CoA was confirmed postnatally in 55 neonates (50.9%). Arch hypoplasia yielded the highest correlation with CoA. The affected neonates presented also significantly lower Z scores of the ascending aorta and of the aortic isthmus. Earlier gestational age at referral was positively correlated with neonatal CoA. An odds ratio-based multiparametric model was designed to build a scoring system (AUC 0.89). In our cohort, no single ultrasound parameter was sufficiently accurate to predict postnatal CoA. The scoring system permitted a better identification of the affected fetuses. [ABSTRACT FROM AUTHOR]

Whiting events are transient phenomena commonly occurring in hardwater lakes and manifesting as a turquoise coloration of surface waters during massive calcium carbonate precipitation. While biological and physico‐chemical drivers of carbonate precipitation are known, their relative contributions in controlling whiting events' timing and spatial extent remain poorly understood. Coupling spatially resolved data obtained for two sampling surveys using multiple analytical techniques and geochemical modeling, this study investigated the mechanisms underlying a whiting event during the early summer of 2019 in Lake Geneva. Satellite observations showed that the phenomenon started during a snowmelt period in the catchment at the Rhône River delta before spreading along the lake's northern shore and covering vast areas of its deeper basin. Authigenic calcite precipitated at the river mouth during mixing of warmer calcite super‐saturated lake surface waters with colder snowmelt‐diluted, sediment‐rich river water containing detrital carbonates as potential nucleation sites. The development of the whiting event depended upon the thermal stratification of the water column and the existence of a physically stable metalimnion, within which a river interflow transported finer particles across the lake. During transport, the whiting plume enriched in authigenic carbonates by settling of coarser detrital particles and additional precipitation likely both on the fine‐grained carbonate fraction and through biologically induced mechanisms in the superficial layers of the lake. This study provides novel mechanistic insights on the conditions controlling whiting events in lakes, highlighting a tight coupling of their dynamics with processes acting at the catchment scale. Plain Language Summary: Some lake waters can transiently and suddenly turn to a bright turquoise coloration, which results from the formation of fine particles of calcium carbonate during so‐called whiting events. While the primary mechanism operating in whiting events (i.e., calcium carbonate precipitation) is known, current knowledge does not explain well the timing of these phenomena, nor their patchy spatial distribution in large lakes. Herein, we combined both large (from satellite data), medium‐scale and small‐scale observations, along with modeling, to investigate a whiting event in the largest lake of Western Europe, Lake Geneva. We show that this whiting event is a compound phenomenon whose timing is determined by a conjunction of specific thermal, biological, and geochemical conditions occurring both in the lake and in its main tributary, the Rhône River. The spatial extent of the whiting event is then driven by the lake water circulation, with a greater extension as the water column of the lake is more stratified. Our study gives supporting evidence to the tight coupling existing between lakes and their catchments and underscores an overlooked role of river‐lake transition zones as important biogeochemical reactors. Key Points: The triggering of a whiting event in a large peri‐alpine lake depends on distinct processes acting both in the lake and across its catchmentDuring the event, initial calcite precipitation occurs in the river‐lake mixing zone due to specific hydrological and geochemical conditionsThe spatial patterns of the whiting plume are constrained by lake hydrodynamics and coupled to distinct precipitation mechanisms in the lake [ABSTRACT FROM AUTHOR]

The influence of human activities on the role of inland waters in the global carbon (C) cycle is poorly constrained. In this study, we investigated the impact of human land use on the sources and biodegradation of dissolved organic matter (DOM) and its potential impact on bacterial respiration in 10 independent catchments of the Lake Geneva basin. Sites were selected along a gradient of human disturbance (agriculture and urbanization) and were visited twice during the winter high-flow period. Bacterial respiration and DOM bioavailability were measured in the laboratory through standardized dark bioassays, and the influence of human land uses on DOM sources, composition and reactivity was assessed from fluorescence spectroscopy. Bacterial respiration was higher in agro-urban streams but was related to a short-term bioreactive pool (0–6 d of incubation) of autochthonous origin, whose relative contribution to the total DOM pool increased with the degree of human disturbance. On the other hand, the degradation of a long-term (6–28 d) bioreactive pool related to terrestrial DOM was independent from the catchment land use and did not contribute substantially to aquatic bacterial respiration. From a greenhouse gas emission perspective, our results suggest that human activities may have a limited impact on the net C exchanges between inland waters and the atmosphere, as most CO2 fixed by aquatic producers in agro-urban streams is cycled back to the atmosphere after biomineralization. Although seasonal and longitudinal changes in DOM sources must be considered, the implications of our results likely apply more widely as a greater proportion of autochthonous-DOM signature is a common feature in human-impacted catchments. Yet, on a global scale, the influence of human activities remains to be determined given the large diversity of effects of agriculture and urbanization on freshwater DOM depending on the local environmental context. [ABSTRACT FROM AUTHOR]

The gas transfer velocity (k) is a major source of uncertainty when assessing the magnitude of lake gas exchange with the atmosphere. For the diversity of existing empirical and process-based k models, the transfer velocity increases with the level of turbulence near the air–water interface. However, predictions for k can vary by a factor of 2 among different models. Near-surface turbulence results from the action of wind shear, surface waves, and buoyancy-driven convection. Wind shear has long been identified as a key driver, but recent lake studies have shifted the focus towards the role of convection, particularly in small lakes. In large lakes, wind fetch can, however, be long enough to generate surface waves and contribute to enhance gas transfer, as widely recognised in oceanographic studies. Here, field values for gas transfer velocity were computed in a large hard-water lake, Lake Geneva, from CO2 fluxes measured with an automated (forced diffusion) flux chamber and CO2 partial pressure measured with high-frequency sensors. k estimates were compared to a set of reference limnological and oceanic k models. Our analysis reveals that accounting for surface waves generated during windy events significantly improves the accuracy of k estimates in this large lake. The improved k model is then used to compute k over a 1-year time period. Results show that episodic extreme events with surface waves (6 % occurrence, significant wave height > 0.4 m) can generate more than 20 % of annual cumulative k and more than 25 % of annual net CO2 fluxes in Lake Geneva. We conclude that for lakes whose fetch can exceed 15 km , k models need to integrate the effect of surface waves. [ABSTRACT FROM AUTHOR]

Lakes emit substantial amounts of carbon dioxide (CO2) into the atmosphere, but why they do remains debated. The long-standing vision of lakes as solely respirators of the organic matter leaking from the soils has been challenged by evidence that inorganic carbon produced by weathering of the catchment bedrock could also support lake CO2 emissions. How inorganic carbon inputs ultimately generate lake CO2 outgassing remains a blind spot. We develop and introduce a calcite module in a coupled one-dimensional physical-biogeochemical model that we use to simulate the carbon cycle of the large Lake Geneva over the past 40 years. We mechanistically demonstrate how the so-far neglected process of calcite precipitation boosts net CO2 emissions at the annual scale. Far from being anecdotal, we show that calcite precipitation could explain CO2 outgassing across various lakes globally, including some of the largest lakes in the world. [ABSTRACT FROM AUTHOR]

The influence of human activities on the role of inland waters in the global carbon (C) cycle is poorly constrained. In this study, we investigated the impact of human land use on the degradation of terrestrial dissolved organic matter (DOM) and its potential impact on bacterial respiration in ten independent catchments of the Lake Geneva Basin. Sites were selected along a gradient of human disturbance (agriculture and urbanization), and we monitored bacterial respiration in parallel to DOM bioavailability. Fluorescence spectroscopy was used to determine the influence of human land uses on DOM sources and composition as well as the dynamic of degradation or production of the fluorophores identified in our study sites. Higher bacterial respiration measured in agro-urban streams related to a short-term bioreactive pool (0-6 days of incubation) from autochthonous origin, whose the size increased with human disturbance. On the other hand, the degradation of terrestrial DOM was not impacted by human activities and was not found to contribute substantially to aquatic bacterial respiration. Although human land uses controlled DOM sources, composition and bioavailability at the basin scale, our results showed that human activities in the Lake Geneva Basin had a limited impact on the net C exchanges between inland waters and the atmosphere related to DOM mineralization. Considering that greater proportion of autochthonous-DOM signature is a common feature in human-impacted catchments, the implications of our results likely apply more widely. Yet, on a global scale, the influence of human activities remains to be determine given the large diversity of effects of agriculture and urbanization on freshwater DOM depending on the local environmental context. [ABSTRACT FROM AUTHOR]

The rates of gross primary production (GPP), ecosystem respiration (R), and net ecosystem production (NEP) provide quantitative information about the cycling of carbon and energy in aquatic ecosystems. In lakes, metabolic rates are often diagnosed from diel oxygen fluctuations recorded with high‐resolution sondes. This requires that the imprint of ecosystem metabolism can be separated from that of physical processes. Here, we quantified the vertical and temporal variability of the metabolic rates of a deep, large, mesotrophic lake (Lake Geneva, Switzerland–France) by using a 6‐month record (April–October 2019) of high‐frequency, depth‐resolved (0–30 m) dissolved oxygen measurements. Two new alternative methods (in the time and frequency domain) were used to filter low‐frequency basin‐scale internal motions from the oxygen signal. Both methods proved successful and yielded consistent metabolic estimates showing net autotrophy (NEP = GPP − R = 55 mmol m−2 day−1) over the sampling period and depth interval, with GPP (235 mmol m−2 day−1) exceeding R (180 mmol m−2 day−1). They also revealed significant temporal variability, with at least two short‐lived blooms occurring during calm periods, and a vertical partitioning of metabolism, with stronger diel cycles and positive NEP in the upper ∼10 m and negative NEP below, where the diel oxygen signal was dominated by internal motions. The proposed methods expand the range of applicability of the diel oxygen technique to large lakes hosting energetic, low‐frequency internal motions, offering new possibilities for unveiling the rich spatiotemporal metabolism dynamics in these systems. Plain Language Summary: Quantifying the rates of production and degradation of organic matter is of fundamental importance for understanding the cycling of carbon in lakes and for assessing and managing the health of these ecosystems. Owing to the increased availability of high‐resolution sondes, this quantification is now frequently achieved by recording changes of oxygen concentration directly in free‐water, allowing for an unprecedented temporal coverage. In small, shallow, productive lakes, the application of this method is relatively straightforward because oxygen changes driven by biological processes are larger than vertical transport. Instead, large, deep lakes host large‐amplitude vertical motions, which can significantly impact the oxygen record, hindering the calculation of metabolic rates. In this study, we quantified the metabolism of Lake Geneva during the productive period of 2019 with continuous oxygen measurements at different depths. To obtain reliable metabolic rates, we developed new analytical techniques allowing for the isolation of the biological signal. This study unveils the rich spatiotemporal metabolic dynamics of Lake Geneva, which would remain unnoticed with traditional sampling techniques, and provides new insights and mathematical tools for improving the application of the free‐water oxygen technique in large and energetic systems. Key Points: Metabolic rates diagnosed with high‐resolution free‐water oxygen measurements in Lake GenevaTwo new methods proposed to filter the imprint of vertical dislocations that interferes with the diel oxygen signalThe summer metabolism of Lake Geneva is net autotrophic and shows both rich vertical structures and temporal dynamics [ABSTRACT FROM AUTHOR]

The article offers information on the occurrence of nodular gill disease in farmed brown trout. Topics discussed include information on the Nodular gill disease (NGD) as an emerging ectoparasitic condition by amoebae causing significant mortality in some species of salmonids farmed in freshwater environment; Nodular gill disease caused by different species of amoebae; and the role of NGD in highly intensive farming systems in production losses.

Sediment export from glaciated basins involves complex interactions between ice flow, basal erosion and sediment transfer in subglacial and proglacial streams. In particular, we know very little about the processes associated with sediment transfer by subglacial streams. The Haut Glacier d'Arolla (VS, Switzerland) was investigated during the summer melt season of 2015. LiDAR survey revealed positive surface changes in the ablation zone, indicating glacier uplift, at the end of the morning during the period of peak ablation. Instream measures of sediment transport showed that suspended load and bedload responded differently to diurnal flow variability. Suspended load depended on the availability of fine material whereas bedload depended mainly on the competence of the flow. Interpretation of these results allowed development of a conceptual model of subglacial sediment transport dynamics. It is based upon the mechanisms of clogging (deposition) and flushing (transport/erosion) in sub‐glacial channels as forced by diurnal flow variability. Through the melt season, the glacier hydrological response evolves from being buffered by glacier snow cover with a poorly developed subglacial drainage system to being dominated by more rapid ice melt with a more hydraulically efficient subglacial channel system. The resultant changes in the shape of diurnal discharge hydrographs, and notably higher peak flows and lower base flows, causes sediment transport to become discontinuous, with overnight clogging and late morning flushing of subglacial channels. Overnight clogging may be sufficient to reduce subglacial channel size, creating temporarily pressurized flow and lateral transfer of water away from the subglacial channels, leading to the late morning glacier surface uplift. However, without further data, we cannot exclude other hypotheses for the uplift. © 2018 John Wiley & Sons, Ltd. Conceptual model of the daily subglacial sediment transport dynamics with flow cycle induced by melting ice integrating the glacial surface uplift. Phase c: before the critical transport capacity of coarse sediments is achieved (schematic cross‐section East–West of glacial tongue of the Haut Glacier d'Arolla with median supgraglacial moraine). [ABSTRACT FROM AUTHOR]

To date, there is no description in literature of osteosarcoma of the jaw in fish, which is a rare occurrence also among mammalian osteosarcomas including humans (Chaudhary & Chaudhary, 2012; Selmic et al., 2014). Keywords: immunohistochemistry; metastases; osteocalcin; osteosarcoma; trout EN immunohistochemistry metastases osteocalcin osteosarcoma trout 483 485 3 03/11/21 20210401 NES 210401 Bone and cartilage neoplasia is uncommon in fish (Groff, 2004; Roberts, 2012). Immunohistochemistry, metastases, osteocalcin, osteosarcoma, trout. [Extracted from the article]

Results A total of 777 euploid fetuses with confirmed CHD were included in the study group, of which 711 were conceived spontaneously and 66 with assisted reproductive technology (ART) (26 homologous IVF, 28 ICSI and 12 heterologous IVF). CHD were categorised in 4 groups: Obstruction Left Ventricle Outflow Tract (LVOT), Conotruncal Abnormalities (CNTRA), Valve Defects (VD), Atrioventricular septal defects (AVSD). Where more than one type of CHD was present, CNTR plus VD/AVSD were present only in SP and homologous IVF, not in heterologous IVF. [Extracted from the article]

Objectives: To analyze the role of middle cerebral artery (MCA) peak systolic velocity (PSV) in the prediction of severe fetomaternal hemorrhage (FMH) and to compare it with standard biophysical assessment. Data Sources: Retrospective review of cases of FMH seen in our unit and systematic review of the literature. Results: We followed the MOOSE guidelines to review the literature. From 838 articles, 16 were selected. In total, 35 women, including 3 cases from our center and 32 obtained from the literature search were included. Diagnosis of FMH was always confirmed by laboratory tests. Patients were seen at 31 ± 5 weeks' gestation (range 16-39) and the most frequent indication for referral was decreased perception of fetal movements. Cardiotocography (CTG) upon admission was sinusoidal in 18 cases, nonreactive in 6, decelerative in 2 and tachycardic in one. MCA-PSV was abnormal in all cases but one. There were 2 perinatal deaths. The mean hemoglobin concentration at birth or at intrauterine transfusion was 4.8 ± 1.9 g/dl. Discussion: The most accurate predictor of FMH was fetal MCA-PSV. CTG was always abnormal but the pattern was frequently nonspecific. We suggest including fetal cerebral Doppler in the evaluation of patients with decreased fetal movements, particularly in those cases with ambiguous results of biophysical testing. [ABSTRACT FROM AUTHOR]

The article provides an analysis of nodular gill disease in farmed rainbow trout in Italy. Topics discussed include identifying the aetiology of the disease, subjecting gills to parasitological examination by light microscopic observation, and use of nuclear pleomorphism to characterize epithelial cells. The article discusses nodular gill disease of rainbow trout as a serious emerging problem in Italy.

Objective: To assess the risk of 22q11.2 deletion in fetuses with a prenatal diagnosis of right aortic arch without intracardiac anomalies (RAA-no ICA).Methods: This was a retrospective study of all fetuses with RAA-no ICA diagnosed prenatally at three referral centers, between 2004 and 2014. A detailed sonographic examination was performed in each case, including visualization of the thymus and of the head and neck vessels to identify the presence of an aberrant left subclavian artery (ALSA). Karyotyping and fluorescence in situ hybridization analysis for diagnosis of 22q11.2 deletion were always offered either prenatally or postnatally. Clinical and echocardiographic examinations were performed in livebirths and a postmortem examination in cases of termination of pregnancy.Results: During the study period, 85 fetuses were diagnosed prenatally with RAA-no ICA. Genetic or clinical data were not available for three cases and these were excluded from analysis. 22q11.2 deletion was found in 7/82 cases (8.5% (95% CI, 3.8-17.3%)). The thymus was small or non-visualized in all seven cases and additional abnormal sonographic findings were present in four.Conclusion: 22q11.2 deletion is present in a clinically significant proportion of fetuses with a prenatal diagnosis of RAA-no ICA. In such cases, a detailed sonographic examination, with assessment of the thymus in particular, may be useful to further define the level of risk for 22q11.2 deletion. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]