Post-Depositional Biodegradation Processes of Pollutants on Glacier Surfaces

Glaciers are important fresh-water reservoirs for our planet. Although they are often located at high elevations or in remote areas, glacial ecosystems are not pristine, as many pollutants can undergo long-range atmospheric transport and be deposited on glacier surface, where they can be stored for long periods of time, and then be released into the down-valley ecosystems. Understanding the dynamics of these pollutants in glaciers is therefore important for assessing their environmental fate. To this aim, it is important to study cryoconite holes, small ponds filled with water and with a layer of sediment, the cryoconite, at the bottom, which occur on the surface of most glaciers. Indeed, these environments are hotspots of biodiversity on glacier surface as they host metabolically active bacterial communities that include generalist taxa able to degrade pollutants. In this work, we aim to review the studies that have already investigated pollutant (e.g., chlorpyrifos and polychlorinated-biphenyls (PCBs)) degradation in cryoconite holes and other supraglacial environmental matrices. These studies have revealed that bacteria play a significant role in pollutant degradation in these habitats and can be positively selected in contaminated environments. We will also provide indication for future research in this field

2:1 ketogenic diet and low-glycemic-index diet for the treatment of chronic and episodic migraine: a single-center real-life retrospective study

Aims: The evidence supporting the efficacy of dietary preventive therapy in migraine is rising, particularly regarding the ketogenic diet. However, less evidence exists for the Low-Glycemic Index Diet and the 2:1 KD. This retrospective single-center real-life study aims to evaluate the efficacy of a 2:1 ketogenic diet and a Low-Glycemic-index Diet in chronic and high-frequency episodic migraine. Methods: Sixty patients with high-frequency episodic and chronic migraine were treated with either a Low-Glycemic-index diet (39 patients) or a 2:1 (21 patients) ketogenic diet for three months. We collected data on the migraine frequency and intensity and the MIDAS and HIT-6 scores through the headache diary. Anthropometric measurements (BMI, fat mass, free fat mass, and weight) were also collected and analyzed similarly. Data obtained at the baseline and after three months of each diet were compared. Results: Migraine intensity, frequency, MIDAS and HIT-6 scores, fat mass, weight, and BMI improved in both diet groups. Conclusions: Both diets are effective in reducing migraine symptoms and migraine-related disability

Bacterial communities of cryoconite holes of a temperate alpine glacier show both seasonal trends and year-to-year variability

Cryoconite holes are small depressions of the glacier surface filled with melting water and with a wind-blown debris on the bottom. These environments are considered hot spots of biodiversity and biological activities on glaciers and host communities dominated by bacteria. Most of the studies on cryoconite holes assume that their communities are stable. However, evidence of seasonal variation in cryoconite hole ecological communities exists. We investigated the variation of the bacterial communities of cryoconite holes of Forni Glacier (Central Italian Alps) during the melting seasons (July-September) 2013 and 2016, for which samples at three and five time-points, respectively were available. Bacterial communities were characterized by high-throughput Illumina sequencing of the hypervariable V5'V6 regions of 16S rRNA gene, while meteorological data were obtained by an automatic weather station. We found consistent trends in bacterial communities, which shifted from cyanobacteria-dominated communities in July to communities dominated by heterotrophic orders in late August and September. Temperature seems also to affect seasonal dynamics of communities. We also compared bacterial communities at the beginning of the melting season across 4 years (2012, 2013, 2015 and 2016) and found significant year-to-year variability. Cryoconite hole communities on temperate glaciers are therefore not temporally stable

Global variability and controls on the accumulation of fallout radionuclides in cryoconite

The accumulation of fallout radionuclides (FRNs) from nuclear weapons testing and nuclear accidents has been evaluated for over half a century in natural environments; however, until recently their distribution and abundance within glaciers have been poorly understood. Following a series of individual studies of FRNs, specifically 137Cs, 241Am and 210Pb, deposited on the surface of glaciers, we now understand that cryoconite, a material commonly found in the supraglacial environment, is a highly efficient accumulator of FRNs, both artificial and natural. However, the variability of FRN activity concentrations in cryoconite across the global cryosphere has never been assessed. This study thus aims to both synthesize current knowledge on FRNs in cryoconite and assess the controls on variability of activity concentrations. We present a global database of new and previously published data based on gamma spectrometry of cryoconite and proglacial sediments, and assess the extent to which a suite of environmental and physical factors can explain spatial variability in FRN activity concentrations in cryoconite. We show that FRNs are not only found in cryoconite on glaciers within close proximity to specific sources of radioactivity, but across the global cryosphere, and at activity concentrations up to three orders of magnitude higher than those found in soils and sediments in the surrounding environment. We also show that the organic content of cryoconite exerts a strong control on accumulation of FRNs, and that activity concentrations in cryoconite are some of the highest ever described in environmental matrices outside of nuclear exclusion zones, occasionally in excess of 10,000 Bq kg−1. These findings highlight a need for significant improvements in the understanding of the fate of legacy contaminants within glaciated catchments. Future interdisciplinary research is required on the mechanisms governing their accumulation, storage, and mobility, and their potential to create time-dependent impacts on downstream water quality and ecosystem sustainability

Mid-Devensian climate and landscape in England : new data from Finningley, South Yorkshire

While there is extensive evidence for the Late Devensian, less is known about Early and Middle Devensian (approx. 110–30 ka) climates and environments in the UK. The Greenland ice-core record suggests the UK should have endured multiple changes, but the terrestrial palaeo-record lacks sufficient detail for confirmation from sites in the British Isles. Data from deposits at Finningley, South Yorkshire, can help redress this. A channel with organic silts, dated 40 314–39 552 cal a BP, contained plant macrofossil and insect remains showing tundra with dwarf-shrub heath and bare ground. Soil moisture conditions varied from free draining to riparian, with ponds and wetter vegetated areas. The climate was probably low arctic with snow cover during the winter. Mutual climatic range (MCR), based on Coleoptera, shows the mean monthly winter temperatures of −22 to −2°C and summer ones of 8–14°C. Periglacial structures within the basal gravel deposits and beyond the glacial limits indicate cold-climate conditions, including permafrost. A compilation of MCR reconstructions for other Middle Devensian English sites shows that marine isotope stage 3—between 59 and 28 ka—experienced substantial variation in climate consistent with the Greenland ice-core record. The exact correlation is hampered by temporal resolution, but the Finningley site stadial at approximately 40 ka may correlate with the one of the Greenland stadials 7–11

Revisione del genere Psammodius Fall\ue9n: 3. Le specie del gruppo plicatulus del Continente Antico (Coleoptera, Aphodiidae)

Volume: 87Start Page: 67End Page: 7

Une nuova sottospecie iraniana di Onthophagus ruficapillus Brull\ue9 (Colleoptera Scarabaeidae)

Volume: 89Start Page: 517End Page: 51

Strings attached: Socioemotional wealth mixed gambles in the cash management choices of family firms

Family owners differ from other types of owners due to the presence of socioemotional wealth (SEW) concerns. We take a closer look at this distinctive aspect by examining the impact of family control and influence dimension of SEW on the cash management choices of family firms, conceptualizing it as a mixed gamble choice. Our empirical analysis of 195 Italian firms listed on the Milan Stock Exchange between 2003 and 2015 shows that family firms derive more value and incur lower costs than nonfamily firms when they increase their cash holdings. We then delve deeper into family firms’ cash management choices by exploring how different levels of family control and influence as well as types of board governance arrangements moderate this relationship. The empirical results indicate that the positive effects of family ownership are more pronounced under a high level of family control and influence and with separation of the board chair and CEO positions

La ricerca inventa il mercato

Le caratteristiche delle start-up tecnologiche rendono il processo di marketing particolarmente problematico. Il capitolo si propone di analizzare le specificit\ue0 e le principali problematiche che una nuova impresa che opera in un mercato high-tech affronta nel momento in cui deve definire la sua strategia e le sue politiche di marketing. Vengono presentati alcuni schemi teorici che possono agevolare questo processo decisionale