Thermal patterns in a proglacial pond create Windows of Opportunity for periphyton growth (Cevedale glacier, Italy)

In high mountain areas, deglaciation is the most evident effect of anthropogenic climatic changes. Glacier retreat is inducing worldwide an increase of both number and size of proglacial lakes and ponds, i.e., lentic water bodies located in the proglacial area and directly linked to the glacier activity: the depressions carved in the land surface allow meltwater impoundment and accumulation of glacier sediment. Over the past decades, glacier-fed lakes have become an increasingly represented ecosystem in the Alpine landscape. However, their ecological characteristics are only partially known. Glacial runoff determines cascade effects in glacier-fed standing waters. It influences both water temperature, by delivering cold meltwater to the system, and water transparency, because of the high amount of inorganic suspended solids (so called “glacial flour”) that determine high water turbidity. Therefore, proglacial lakes are highly selective habitats, where planktonic communities are quantitatively scarce and taxonomically simplified. On the other hand, given the low input of allochthonous organic matter from bare proglacial forefields, benthic primary producers (periphyton) are the major autochthonous carbon source sustaining food webs in glacially fed water bodies. Studies on glacial streams show that periphyton growth is concentrated in “Windows of Opportunity” (WOs), mainly occurring in periods of reduced glacial runoff, i.e., autumn. In the euphotic zone along the littoral area of proglacial lakes, local conditions can allow algal growth (e.g., cyanobacteria), and the abrasive impact of glacial flour is low due to scarce water turbulence. Furthermore, in lentic proglacial ecosystems, periphyton ecological niches appear to be influenced also by water thermal stratification dynamics. Previous studies observed different mixing patterns in proglacial and clear mountain lakes (i.e., without glacial influence); high-altitude ponds (surface area < 2 ha) are expected to show even different patterns of response to physical environmental setting. To better understand the link between thermal dynamics and ecology of proglacial lentic systems, we investigated temperature dynamics in the water column of a proglacial pond located in the Eastern Italian Alps (South Tyrol, Italy) and compared them with density and taxonomic composition of PPNW 2024. Universitat de Girona (Spain) benthic diatom communities, which are key components of littoral periphyton in lakes and are useful bioindicators of environmental changes. Diatoms are eukaryotic photosynthetic microalgae, characterised by a cell wall composed of silica (frustule), whose morphological characteristics are used for taxonomical identification. Specific aims of the study were: (i) to characterise the temperature dynamics in a shallow proglacial pond; (ii) to investigate how thermal dynamics can influence the presence of WOs for periphyton growth. The proglacial pond is located at 2850 m a.s.l. in the Martell valley (Stelvio National Park, CE Italian Alps). It is moraine-dammed and originated from the retreat of the Cevedale glacier about 10 years ago. Its surface area is about 4270.5 m2 with a maximum depth of around 3 m. In the ice-free seasons 2022 and 2023, we installed water level sensors and performed water discharge measurements at the pond outlet with the salt dilution method, to build a flow rating curve and estimate outlet and inlet discharge time series. In summer 2023, we installed two buoys, one in the upstream part of the pond and one in the downstream part. Each buoy was equipped with 5 temperature sensors, located at 0, 0.2, 0.4, 0.8, 1.6 m depth, recording water temperature at 5-minute intervals. We applied the CE-QUAL-W2 model, a 2-D hydrodynamic laterally averaged model, to reconstruct the temperature time series in the water column for both ice-free seasons 2022 and 2023. We calibrated the parameters of the model based on field buoy data. Meteorological data and discharge time series were used as boundary conditions for the model. We developed a simplified numerical model to estimate the inflow water temperature (i.e., glacial runoff running on debriscovered ice) as a function of air temperature and solar radiation. Preliminary results show good agreement between the observed and modelled temperature data (RMSE < 1.5°C). During the Alpine glacial summer, we observed periods of pronounced daily thermal stratification. In these periods, shallow layers showed daily fluctuations, while deeper layers were colder. Total mixing and cooling of the water column followed intense precipitation events, with lower air temperature and solar radiation. In 2022 and 2023, we analysed the benthic diatom communities collected from a known area of colonised substrata (stones covered by a layer of consolidated sediment). In the laboratory, we eliminated the organic matter in the samples by chemical oxidation, to allow the morphological observation of diatom frustules. We equalised the sample volumes at 6 ml and added an aliquot (1 ml) of solution containing a known concentration of divinylbenzene microspheres, which served as reference to compare diatom densities in the different samples. Permanent diatom mounts were prepared, and diatom frustules and microspheres were counted under the optical microscopy. Diatom communities in the Cevedale proglacial pond reached higher density values (1-43 and 2.8-404.9 × 103 N valves/cm2, respectively) than in glacier-fed streams investigated in the same geographical area (Vulcano 2020, unpublished data). Moreover, we observed a density peak in August 2022 (404.9 × 103 N valves/cm2), and not in autumn as expected. In all samples, the community was numerically dominated by the pioneer species Achnanthidium minutissimum s.l. The observed diatom density patterns suggest that periphyton PPNW 2024. Universitat de Girona (Spain) growth in the proglacial pond can be sustained also in periods of high glacial runoff. Accordingly, the model results suggest the presence of additional temperature-driven WOs for periphyton growth during the Alpine summer, with respect to the ones described in glacier-fed streams. The presence and temporal extension of the WOs in the proglacial pond depend on meteorological conditions, as thermal gradients form during dry and warm periods. In a climate change perspective, this implies that colonisation processes in the periphyton of newly formed proglacial ponds may be accelerated by prolonged periods of drought, high air temperatures and increased glacial runoff. Consequently, the natural ecological evolution of proglacial ponds may be accelerated by global warming

Benthic diatom communities in two proglacial lakes with different glacial influence (Cevedale glacier, Italy).

Climatic changes induce cascadeeffects on high mountain headwaters. Due to the current deglaciation, proglacial lakes increased worldwide in number and volume in the last decades, thus becoming more represented ecosystems in high mountain landscapes. With the progression of glacier retreat, proglacial lakes rapidly evolve from ice contact conditions towards ice distal conditions. The final evolution stage is a clear water mountain lake, with no glacial influence. In the European Alps, ice distal proglacial lakes represent the largest proportion of high mountain lakes, in comparison with ice contact ones and clear lakes. Glacial runoff is typically cold and contains large amounts of inorganic suspended solids (so called “glacial flour”). Due to low water temperature and high turbidity, proglacial lakes are highly selective habitats, where planktonic communities are taxonomically simplified and quantitatively scarce. Nonetheless, littoral habitat conditions may sustain algal growth. However, benthic assemblages have been scarcely addressed by studies on Alpine proglacial lakes regarding qualitative and especially quantitative aspects. Here, we provide a first characterisation of the littoral diatom assemblages of two Alpine proglacial lakes with different glacial influence and discuss differences in community composition between the ice contact and the ice distal lake habitat. The two lakes are located between 2700 and 2900 m a.s.l. in the Martello Valley (Stelvio National Park, Province of Bolzano, Italy). They formed in the past decades in the depressions of the land surface shaped by the retreat of the Cevedale glacier and are both dammed by moraines. The ice contact lake (CL) receives glacial runoff flowing on debris-covered ice. The ice distal lake (DL) is about 500 m downstream and hydrologically connected to CL. In the ice-free seasons 2022 and 2023, we collected quantitative diatom samples from colonised substrata (stones or cohesive sediment) during the different stages of the Alpine glacial summer (snow melt, glacier ablation and base flow). In parallel, we collected water samples to analyse chemical habitat conditions and installed temperature dataloggers in the water column to calibrate a 2D laterally-averaged hydrodynamic model that allowed to reconstruct lake thermal dynamics. The two lacustrine habitats differed mainly in water turbidity, littoral water temperature and thermal dynamics, i.e., stratification patterns. In addition, we found differences in the benthic diatom communities of the two proglacial lakes. Alpha diversity was higher in the ice distal lake (DL), where we found species that were not observed in the ice contact lake (CL). In CL, diatom density peaks corresponded to the increase of Achnanthidium minutissimum s.l. (Kützing) Czarnecki, which was the numerically dominant species in all the samples in this lake. Density peaks in DL were characterised by different dominant species during the Alpine summer and the community composition showed a species succession. Furthermore, in DL, we observed a stable population of Pinnularia bullacostae Krammer & Lange-Bertalot. At the best of out knowledge, this is the first record of the species in the European Alp

Preliminary results on the evolution of proglacial ponds in the deglaciating Alps

Deglaciation is one of the most evident effects of the ongoing climatic changes on the Alpine environment. One of its common consequences is the formation of new water bodies in the proglacial area, where proglacial lakes and ponds are increasingly relevant ecosystems for the mountain landscape. The EVERLAKE project focuses on a recent system of proglacial ponds that originated from the retreat of the Zufall/Cevedale Glacier (Plima catchment, Central/Eastern Italian Alps). The aims of the project are to: (i) provide a first hydroecological characterisation of these pond ecosystems from a physical, chemical and biological point of view; (ii) understand their evolutionary trend during the process of deglaciation, with a space-for-time substitution approach. Here, we present data collected during the ice-free season 2022, showing the seasonal development occurring in three ponds located along a gradient of distance from the Cevedale Glacier terminus (i.e., at 2700-2900 m a.s.l.). We monitored water level, temperature and electrical conductivity and assessed the origin of water through analyses of stable isotopes (δ2H, δ18O). Bathymetric measurements were performed to estimate the residence time of each waterbody. We also analysed basic water chemistry, concentrations of trace elements, benthic and planktonic chlorophyll-a and organic content. The biological communities of these poorly known aquatic ecosystems were characterised by adopting an integrated approach combining morphological observations of microalgae and 16S and 18S rRNA metabarcoding of eDNA from both benthic and planktonic samples. The ponds showed different ecological conditions related to their distance from the glacier margins

Effects of a water extract of Lepidium meyenii root in different models of persistent pain in rats

Abstract Lepidium meyenii (Walp.), commonly called maca, is an Andean crop belonging to the Brassicaceae family. Maca hypocotils are habitually consumed as customary food as well as traditional remedies for pathological conditions such as infertility. Moreover, the characterization of maca extracts revealed the presence of compounds that are able to modulate the nervous system. Aimed to evaluate the efficacy of L. meyenii in persistent pain, the present study analyzed the effects of a commercial root extract from maca in different animal models reproducing the most common causes of chronic painful pathologies. A qualitative characterization of this commercial extract by high performance liquid chromatography-mass spectrometry and tandem mass spectrometry analyses allowed us to confirm the presence of some macamides known as bioactive constituents of this root and the absence of the main aromatic glucosinolates. The acute oral administration of maca extract is able to reduce mechanical hypersensitivity and postural unbalance induced by the intra-articular injection of monoiodoacetate and the chronic-constriction injury of the sciatic nerve. Furthermore, L. meyenii extract reverts pain threshold alterations evoked by oxaliplatin and paclitaxel. A good safety profile in mice and rats was shown. In conclusion, the present maca extract could be considered as a therapeutic opportunity to relieve articular and neuropathic pain.</jats:p

Nationwide survey on the management of pediatric pharyngitis in Italian emergency units

Background: Acute pharyngitis is a frequent reason for primary care or emergency unit visits in children. Most available data on pharyngitis management come from primary care studies that demonstrate an underuse of microbiological tests, a tendency to over-prescribe antibiotics and a risk of antimicrobial resistance increase. However, a comprehensive understanding of acute pharyngitis management in emergency units is lacking. This study aimed to investigate the frequency of rapid antigen test use to diagnose acute pharyngitis, as well as other diagnostic approaches, the therapeutic attitude, and follow-up of children with this condition in the emergency units. Methods: A multicentric national study was conducted in Italian emergency departments between April and June 2022. Results: A total of 107 out of 131 invited units (response rate 82%), participated in the survey. The results showed that half of the units use a scoring system to diagnose pharyngitis, with the McIsaac score being the most commonly used. Most emergency units (56%) were not provided with a rapid antigen diagnostic test by their hospital, but the test was more frequently available in units visiting more than 10,000 children yearly (57% vs 33%, respectively, p = 0.02). Almost half (47%) of the units prescribe antibiotics in children with pharyngitis despite the lack of microbiologically confirmed cases of Group A β-hemolytic streptococcus. Finally, about 25% of units prescribe amoxicillin-clavulanic acid to treat Group A β-hemolytic streptococcus pharyngitis. Conclusions: The study sheds light on the approach to pharyngitis in emergency units, providing valuable information to improve the appropriate management of acute pharyngitis in this setting. The routinary provision of rapid antigen tests in the hospitals could enhance the diagnostic and therapeutic approach to pharyngitis

Management of whiplash-associated disorder in the Italian emergency department: the feasibility of an evidence-based continuous professional development course provided by physiotherapists

Purpose: The management of whiplash and associated disorders (WAD) in the Italian Health System is still empirical and influenced by a single professional’s expertise. Therefore, the purpose of our study is to describe a structured management changes in an Italian emergency department (ED) after an evidence based continuous professional development (CPD) course. Methods: A CPD course was organized by Orthopedic Manipulative Physical Therapists (OMPT) for personnel of ED in the hospital Girolamo Fracastoro (San Bonifacio, Verona, Italy), based on latest scientific evidence. Data regarding the number of X-Rays, computed tomography (CT) scan, orthopaedic referrals, neck collars and WAD IV (i.e., severe diagnosis) before and after the course were compared. Results: 3066 cases of WAD have been analyzed in 2016 and 2185 in 2017/2018. The number of X-Rays dropped down from 15.1% to 13.5%; the CT scans increased from 1.3% to 1.9%; the WAD IV diagnosis increased from 0.7% to 1.6%; the orthopaedic referrals dropped from 1.5% to 1.1%; the collars prescription dropped from 8.8% to 2.5%. Conclusion: An updated framework increased the efficiency of ED’s maintaining the same level of safety (i.e., WAD IV diagnosis). Given that, it can also be argued that, in line with other countries, the implementation of an OMPT role within the ED multidisciplinary team is advised also in Italy.Implications for rehabilitation Physiotherapists were commissioned to organize a management change of patients in an Italian Emergency Department clinical setting for the management of whiplash; Guidelines and other appropriate clinical rules facilitate the delivery of an evidence-based and more appropriate management and care plan; An inter-disciplinary continuous professional development course has the potential to positively influence patients’ journey and to optimize the use of departmental resources; The involvement of other health professionals (e.g., Physiotherapists) within the Italian Emergency Department organizational chart might lead to further improvement of service provided