Mountain glaciers darkening: geochemical characterizazion of cryoconites and their radiative impact on the Vadret da Morteratsch (Swiss Alps)

Mountain glaciers represent an important source of fresh water across the globe. It is well known that these reservoirs are seriously threatened by global climate change, and a widespread reduction of glacier extension has been observed in recent years. Surface processes that promote ice melting are driven both by air temperature/precipitation and surface albedo. This latter is mainly influenced by the growth of snow grains and by the impurities content (such as mineral dust, soot, ash etc.). The origin of these light-absorbing impurities can be local or distal, and often, as a consequence of melting processes, they can aggregate on the glacier tongue, forming characteristics cryoconites, that decrease ice albedo and hence promote the melting. In this contribution, we coupled satellite images (EO1 \u2013 Hyperion and Landsat 8 - OLI) and ground hyperspectral data (ASD field spectrometer) for characterizing ice and snow surface reflectance of the Vadret da Morteratsch glacier (Swiss Alps). On the glacier ablation zone, we sampled ice, snow, surface dust and cryoconite material. To evaluate the possible impact of anthropogenic and natural emissions on cryoconites formation, we determined their geochemical composition (through the Neutron Activation Analysis, NAA) and the concentration of Black Carbon (BC), Organic Carbon (OC), Elemental Carbon (EC) and Levoglucosan. From satellite data, we computed the Snow Darkening Index (SDI), which is non-linearly correlated with dust content in snow. Results showed that, during 2015 summer season, ice albedo in the ablation zone reached very low values of about 0.1-0.2. The darkening of the glacier can be attributed to the impact of surface dust (from lateral moraine and Saharan desert) and cryoconites, coupled with grain growth driven by the extremely warm 2015 summer. The geochemical characterization of non-ice material contained in the cryoconites can provide important information regarding their source and the possible impact of anthropogenic emissions on cryoconites formation and evolution

mapping the suitability for ice core drilling of glaciers in the european alps and the asian high mountains

ABSTRACTIce cores from mid-latitude mountain glaciers provide detailed information on past climate conditions and regional environmental changes, which is essential for placing current climate change into a longer term perspective. In this context, it is important to define guidelines and create dedicated maps to identify suitable areas for future ice-core drillings. In this study, the suitability for ice-core drilling (SICD) of a mountain glacier is defined as the possibility of extracting an ice core with preserved stratigraphy suitable for reconstructing past climate. Morphometric and climatic variables related to SICD are selected through literature review and characterization of previously drilled sites. A quantitative Weight of Evidence method is proposed to combine selected variables (i.e. slope, local relief, temperature and direct solar radiation) to map the potential drilling sites in mid-latitude mountain glaciers. The method was first developed in the European Alps and then applied to the Asian High Mountains. Model performances and limitations are discussed and first indications of new potential drilling sites in the Asian High Mountains are provided. Results presented here can facilitate the selection of future drilling sites especially on unexplored Asian mountain glaciers towards the understanding of climate and environmental changes

Persistence of Unintegrated HIV DNA Associates With Ongoing NK Cell Activation and CD34+DNAM-1brightCXCR4+ Precursor Turnover in Vertically Infected Patients Despite Successful Antiretroviral Treatment

none11noThe quantification of proviral DNA is raising interest in view of clinical management and functional HIV eradication. Measures of all unintegrated HIV DNA (uDNA) forms in infected reservoir cells provides information on recent replication events that is not found from other proviral DNA assays. To evaluate its actual relevance in a cohort of perinatally-infected adult HIV patients (PHIV), we studied how peripheral blood mononuclear cell uDNA levels correlated with total HIV DNA (tDNA) and with overall replication or innate immune control parameters including NK cell activation/exhaustion and lymphoid turnover. Twenty-two PHIV were included, with successfully controlled HIV (HIV RNA <50 copies/mL) on combined antiretroviral therapy for mean of 8.7 ± 3.9 years. uDNA accounted for 16 [5.2-83.5] copies/µg and was strongly correlated with tDNA (ρ=0.700, p=0.001). Flow cytometric analysis of peripheral NK cells showed that CD69 expression was directly correlated uDNA (p=0.0412), but not with tDNA. Interestingly, CD56-CD16+NK cells which include newly described inflammatory precursors and terminally differentiated cells were directly correlated with uDNA levels (p<0.001), but not with tDNA, and an inverse association was observed between the proportion of NKG2D+ NK cells and uDNA (ρ=-0.548, p=0.015). In addition, CD34+DNAM-1brightCXCR4+ inflammatory precursor frequency correlated directly with uDNA levels (ρ=0.579, p=0.0075). The frequencies of CD56-CD16+ and CD34+DNAM-1brightCXCR4+ cells maintained association with uDNA levels in a multivariable analysis (p=0.045 and p=0.168, respectively). Thus, control of HIV-1 reservoir in aviremic patients on ART is an active process associated with continuous NK cell intervention and turnover, even after many years of treatment. Quantification of linear and circular uDNA provides relevant information on the requirement for ongoing innate immune control in addition to ART, on recent replication history and may help stratify patients for functional HIV eradication protocols with targeted options.openTaramasso, Lucia; Bozzano, Federica; Casabianca, Anna; Orlandi, Chiara; Bovis, Francesca; Mora, Sara; Giacomini, Mauro; Moretta, Lorenzo; Magnani, Mauro; Di Biagio, Antonio; De Maria, AndreaTaramasso, Lucia; Bozzano, Federica; Casabianca, Anna; Orlandi, Chiara; Bovis, Francesca; Mora, Sara; Giacomini, Mauro; Moretta, Lorenzo; Magnani, Mauro; Di Biagio, Antonio; De Maria, Andre

Mapping surface features of an Alpine glacier through multispectral and thermal drone surveys

Glacier surfaces are highly heterogeneous mixtures of ice, snow, light-absorbing impurities and debris material. The spatial and temporal variability of these components affects ice surface characteristics and strongly influences glacier energy and mass balance. Remote sensing offers a unique opportunity to characterize glacier optical and thermal properties, enabling a better understanding of different processes occurring at the glacial surface. In this study, we evaluate the potential of optical and thermal data collected from field and drone platforms to map the abundances of predominant glacier surfaces (i.e., snow, clean ice, melting ice, dark ice, cryoconite, dusty snow and debris cover) on the Zebrù glacier in the Italian Alps. The drone surveys were conducted on the ablation zone of the glacier on 29 and 30 July 2020, corresponding to the middle of the ablation season. We identified very high heterogeneity of surface types dominated by melting ice (30% of the investigated area), dark ice (24%), clean ice (19%) and debris cover (17%). The surface temperature of debris cover was inversely related to debris-cover thickness. This relation is influenced by the petrology of debris cover, suggesting the importance of lithology when considering the role of debris over glaciers. Multispectral and thermal drone surveys can thus provide accurate high-resolution maps of different snow and ice types and their temperature, which are critical elements to better understand the glacier’s energy budget and melt rates

Prevalence of Viral Hepatitis in Unselected, Consecutively Enrolled Patients Hospitalised for SARS-CoV-2

Diagnosing people living with chronic viral hepatitis is challenging due to the absence of symptoms as long as liver decompensated cirrhosis come out. The aim of this retrospective study was to evaluate the prevalence of HBV and/or HCV infections in a non-selected population, hospitalised for SARS-CoV-2 infection in a tertiary care hospital in Northern Italy. During the study period 1,429 patients were admitted to hospital for SARS-CoV-2 infection, serologic tests for HBV and/or HCV were available for 382 (27%) patients and 3 were excluded due to their previous known serologic status. Among 379 patients, 235 (62%) were male, median age was 70 years (range 21-103), 360 (95%) were Caucasian. Among them, 372/379 (98%) were screened for HBsAg, 320/379 (84%) for HBcAb. HBsAg was positive in 2/372 (0.5%, 95% CI 0.0006-0.02) patients (only in one HBV-DNA was performed that was negative), while HBcAb was found positive in 55/320 (17%, 95% CI 0.13-0.22). Among 370/379 (98%) patients screened for HCV, 11/370 (3%, 95% CI 0.02-0.05) had positive HCV-Ab. Five out of 11 (45%) were tested for HCV-RNA that resulted positive in two patients (0.5%, 95% CI 0.0006-0.02). Considering this data, even though the screening was performed in only 27% of study population, a tailored screening in people with known risk factors for hepatitis might be preferable to universal screening in low prevalence areas. Also a prompt diagnostic workout should begin in case of clinical or laboratory suspicion of hepatitis and in those starting immunosuppressive treatments

Is it still worthwhile to perform quarterly CD4+ T lymphocyte cell counts on HIV-1 infected stable patients?

Background: In the last twenty years routine T CD4+ lymphocyte (CD4) cell count has proved to be a key factor to determine the stage of HIV infection and start or discontinue of prophylaxis for opportunistic infections. However, several studies recently showed that in stable patients on cART a quarterly CD4 cell count monitoring results in limited (or null) clinical relevance. The research is intended to investigate whether performing quarterly CD4 cell counts in stable HIV-1 patients is still recommendable and to provide a forecast of the cost saving that could be achieved by reducing CD4 monitoring in such a category of patients. Methods: The study is based on data referring to all HIV-infected patients &gt; 18 years of age being treated at two infectious diseases units located in the metropolitan area of Genoa, Italy. The probability of CD4 cell counts dropping below a threshold value set at 350 cells/mm3 is assessed using confidence intervals and Kaplan-Meier survival estimates, whereas multivariate Cox analysis and logistic regression are implemented in order to identify factors associated with CD4 cell count falls below 350 cells/mm3. Results: Statistical analysis reveals that among stable patients the probability of maintaining CD4 &gt;350 cell/mm3 is more than 98%. Econometric models indicate that HCV co-infection and HIV-RNA values &gt;50 copies/mL in previous examinations are associated with CD4 falls below 350 cells/mm3. Moreover, results suggest that the cost saving that could be obtained by reducing CD4 examinations ranges from 33% to 67%. Conclusions: Empirical findings show that patients defined as stable at enrollment are highly unlikely to experience a CD4 value &lt;350 cell/mm3 in the space/arc of a year. The research supports a recommendation for annual CD4 monitoring in stable HIV-1 patients

Cryoconite as a temporary sink for anthropogenic species stored in glaciers

Cryoconite, the typical sediment found on the surface of glaciers, is mainly known in relation to its role in glacial microbiology and in altering the glacier albedo. But if these aspects are relatively well addressed, the same cannot be said about the geochemical properties of cryoconite and the possible interactions with glacial and peri-glacial environment. Current glacier retreat is responsible for the secondary emission of species deposited in high-altitude regions in the last decades. The role played by cryoconite in relation to such novel geochemical fluxes is largely unknown. Few and scarce observations suggest that it could interact with these processes, accumulating specific substances, but why, how and to what extent remain open questions. Through a multi-disciplinary approach we tried to shed lights. Results reveal that the peculiar composition of cryoconite is responsible for an extreme accumulation capability of this sediment, in particular for some, specific, anthropogenic substances

Budget impact analysis of sofosbuvir-based regimens for the treatment of HIV/HCV-coinfected patients in northern Italy: A multicenter regional simulation

Objectives: Chronic hepatitis C virus (HCV) is a leading cause of hospitalization and death in populations coinfected with human immunodeficiency virus (HIV). Sofosbuvir (SOF) is a pan-genotypic drug that should be combined with other agents as an oral treatment for HCV. We performed a 5-year horizon budget impact analysis of SOF-based regimens for the management of HIV/HCV-coinfected patients. Methods: A multicenter, prospective evaluation was conducted, involving four Italian Infectious Diseases Departments (Galliera, San Martino, Sanremo, and La Spezia). All 1,005 genotype-coinfected patients (30% cirrhotics) under observation were considered (patients in all disease-stages were considered: chronic hepatitis C, cirrhosis, transplant, hepatocellular carcinoma). Disease stage costs per patient were collected; the expected disease progression in the absence of treatment and sustained virological response (SVR) success rate for SOF-based regimens were calculated based on the literature and expert opinion. Drug prices were based on what the National Health Service paid for them. The comparison of \u201cno treatment\u201d disease progression costs versus the economic impact of SOF-based regimens was investigated. Results: Over the following 5 years, the disease progression scenario resulted in direct costs of approximately \u20ac54 million. Assuming an SVR success rate of 90%, average SOF-based regimens cost up to \u20ac50,000 per person, resulting in a final cost of more than \u20ac56 million, so this option is not economically viable. At the average price of \u20ac12,000, SOF-based regimens, expense was \u20ac17 million, saving 68%. At this price level, the economic resources invested in treating mild to moderate fibrosis stage patients would be equal to the amount of direct costs of disease management in this stage, resulting in a valid return of investment in the short-term. Conclusion: Given the high rates of SVR, in the Italian Healthcare System, SOF-based regimens, price is a determinant and a predictor of the overall cost for the Hepatitis C patient\u2019s management. At the average price per therapy of \u20ac12,000 over the next 5 years, SOF-based regimens are becoming highly sustainable

is osteoporosis risk in anorexia nervosa underestimated a case report series

Introduction: Anorexia nervosa (AN) is a mental disorder whose features are deliberate weight loss, disordered body image, and intrusive overvalued fears of gaining weight. Long-term consequences of AN include endocrine dysfunctions leading to secondary amenorrhea, bone loss and/or osteoporosis with an increased risk of bone fracture. Therefore young women with AN may develop a risk for bone fractures comparable to that of postmenopausal women. Methods: In this case report series Bone Mineral Density (BMD) was examined by Dual energy X-ray Absorptiometry (DXA) in 19 hospitalized patients with diagnosis of AN and prolonged amenorrhea. Results: All patients showed a lumbar/femoral bone loss or osteoporosis, with an increased fracture risk comparable to that of postmenopausal women. Conclusions: Our observation suggests that DXA evaluation of anorexic patients with prolonged amenorrhea would be helpful to prevent fracture risk in this population of patients. However, although DXA is almost routinely recommended in women over 65, it is not in young AN patients with prolonged amenorrhea