Long-term research to understand impact of perturbations on lakes: the example of Lake Maggiore

Perturbations linked to the direct and indirect impacts of human activities during the so-called Anthropocene, affect the structure and functioning of lake ecosystems to varying degrees. To understand the patterns and mechanisms of these anthropogenic effects and the extent to which they may drive irreversible changes in ecosystem services, long-term research is required. Studies on the long-term dynamics of plankton may be particularly useful for large and deep lakes whose overall productivity is dominated by pelagic processes. In the open-waters of such lakes, planktonic organisms link and interact with both abiotic and biotic compartments. Here we will analyze 60 years of data on the plankton of the large, deep, subalpine, Lake Maggiore, tracing changes in the pelagic food web which occurred during different phases of the lake\u27s recent evolution. We will document short- to- medium response times by different trophic levels, from microbes, to primary producers and secondary consumers. We will revisit results of past studies based on contemporary and paleolimnological studies and present new analyses to: i) identify any tipping points of the lake trophic evolution, ii) discern effects of recent climatic change, iii) quantify whether inter-annual variability has changed perhaps in responses to changes in thermal stratification regime and warming. By supplementing structural with functional descriptions of long term changes in phyto- and zooplankton communities, we aim to test competing mechanisms underpinning the decade-scale changes we observed

Low molecular weight Adiponectin increases the mortality risk in very old patients

Despite its beneficial role on insulin resistance and atherosclerosis, adiponectin has been frequently reported as an independent positive predictor of cardiovascular mortality. Very few information is available regarding adiponectin isoforms and mortality, in particular in advanced aging. Baseline serum levels of Total Adiponectin and its circulating isoforms (HMW-, MMW-, LMW-Adiponectin) were measured in 97 old patients (mean age: 79 years). Patients were followed up for all-cause mortality (study end-point) for an average of 76.4 ±37.3 months. A positive association was observed for LMW-Ad and all-cause mortality (HR: 1.13, 95% CI: 1.05-1,22, p: 0.002). After multivariate adjustment for age, sex and a previous history of myocardial infarction, higher levels of LMW-Ad were significantly associated with all-cause mortality (HR: 1.11, 95% CI: 1.02-1.21; p: 0.017). Interestingly neither total adiponectin neither the other two circulating isoforms (MMW- and HMW-Ad) showed any significant association with the study end-point. Our data suggest that the association between high serum adiponectin levels and increased mortality rate in elderly is contingent to an unbalanced circulating levels of adiponectin isoforms. The present results support the hypothesis that high levels of Low Molecular Weight adiponectin are a biomarker for mortality risk in very old patients

Indagini limnologiche nell\u27area antistante la Foce del Torrente San Bernardino (Sopralluogo del 2 Dicembre 2008)

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Indagini limnologiche nell\u27area antistante la Foce del Torrente San Bernardino (Sopralluogo del 15 Dicembre 2009)

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Indagini limnologiche nell\u27area antistante la Foce del Torrente San Bernardino (Sopralluogo del 4 Giugno 2008)

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Indagini limnologiche nell\u27area antistante la Foce del Torrente San Bernardino (Sopralluogo del 16 Giugno 2009)

No abstract availabl

Activity of ethanolic extracts of Asparagopsis taxiformis against the major molecular types of Cryptococcus neoformans/C. gattii complex

Infections due to Cryptococcus neoformans/C. gattii complex have been reported to afflict, not only humans but also other mammals including seabirds and cetaceans, proving that the actual animal exposure to these fungi in nature could be underestimated. In this study, antifungal activity of ethanolic extracts obtained from red alga Asparagopsis taxiformis was evaluated against eight major genotypes of the C. neoformans/C. gattii complex, using both disk diffusion and microdilution broth methods. The algal extracts were active against all fungal strains tested and were not cytotoxic to human red blood cells. This study suggests that Asparagopsis taxiformis extracts possess attractive antifungal properties which should encourage the search for new drugs derived from marine algae

Linking crop yields in Tuscany, Italy, to large-scale atmospheric variability, circulation regimes and weather types

AbstractThe paper presents results from a study examining the relationship between large-scale modes of climate variability with the fluctuations in the yield of barley, durum wheat, olives and sunflower crops in Tuscany, Italy. In particular, the blocking circulation over the growing season, with associated hot and dry conditions, decreased yield for olive crops, barley and durum wheat. The teleconnections analysed in this study are the winter North Atlantic Oscillation (NAO) and the Summer North Atlantic Oscillation (SNAO); the West African Monsoon (WAM) and the Intertropical Front (ITF); and although NAO, SNAO, ITF and WAM are not strictly related to each other, the values of these indices are strongly related to the atmospheric circulation regimes and related weather types. Thus, they have an impact on precipitation and temperature patterns in Italy and on yields of important crops in Tuscany. Results show that the large-scale temperate and tropical variability directly influences the crop yield through three main circulation regimes. These patterns illustrate the importance of the large-scale modes, which, together with the associated weather types, have an impact directly on Tuscan crop yields; both barley and olive yields decline significantly when the ITF is further north with warmer and drier conditions in Italy

Clonal heterogeneity in chronic lymphocytic leukemia cells: superior response to surface IgM cross-linking in CD38, ZAP-70-positive cells.

Background Patients with chronic lymphocytic leukemia whose cells express CD38 and ZAP-70 and utilize unmutated Ig VH region genes have a very poor prognosis. We studied whether cells expressing CD38 and ZAP-70 are more susceptible to stimulation through B-cell receptors than are cells that do not express CD38 and ZAP-70.Design and Methods CD38-positive and CD38-negative leukemic cells were separated from single cases and compared for their response to B-cell receptor cross-linking and ZAP-70 expression. Cohort studies were also carried out by measuring the apoptotic response to surface immunoglobulin M (IgM) cross-linking in 82 patients with chronic lymphocytic leukemia and the protein tyrosine phosphorylation induced by surface IgM in 21 patients.Results CD38-positive cells, isolated from cases of chronic lymphocytic leukemia classified as CD38-positive or CD38-negative, expressed more ZAP-70 than the corresponding CD38-negative cells, exhibited more robust protein tyrosine phosphorylation and had a greater tendency to apoptosis upon B-cell receptor cross-linking. In the cohort studies, surface IgM-induced protein tyrosine phosphorylation correlated significantly with CD38 and ZAP-70 expression and with the absence of Ig VH gene mutations. Apoptosis induced by surface IgM cross-linking correlated significantly only with the proportion of CD38-positive cells. Difficulties in finding more definitive correlations were probably related to imprecision in the in vitro test system and in the definition of cases as positive or negative.Conclusions Collectively, these data indicate that CD38-positive, ZAP-70-positive cells have a greater capacity for signaling through the B-cell receptor and suggest a function for B-cell receptor signaling in promoting chronic lymphocytic leukemia cell expansion, especially within the CD38-positive fraction of the leukemic clone

IL-6 Levels Influence 3-Month All-Cause Mortality in Frail Hospitalized Older Patients

The multidimensional prognostic index (MPI) is a sensitive and specific prognosis estimation tool that accurately predicts all-cause mortality in frail older patients. It has been validated to assess the risk of 1-month to 2-year mortality in frail older patients during hospitalization and after hospital discharge. However, whether the MPI is a valid prognostic tool for follow-up periods of different lengths remains to be validated. To this end, we followed up 80 hospitalized patients (female=37, male 43) at least 75 years of age (mean age=82.6±4.4, range=75-94 years) to assess the 3-month all-cause mortality (mean follow-up=61.0 ± 31.7 months [range 4-90 days]). Accordingly, patients were subdivided into low (MPI-1, score 0-0.33), moderate (MPI-2, score 0.34-0.66) and high (MPI-3, score 0.67-1) mortality risk classes. Moreover, baseline biochemical, inflammatory and metabolic parameters, as well as anamnestic and clinical characteristics, were obtained. Although the MPI-3 score was significantly associated with 3-month all-cause mortality in univariate analysis (HR=5.79, 95%CI=1.77-18.92, p=0.004), a multivariate model indicated that only low albumin (HR=0.33, 95%CI=0.16-0.68, p=0.003) and high IL6 (HR=1.01, 95%CI=1.00-1.02, p=0.010) levels were significantly associated with 3-month all-cause mortality. In conclusion, we suggest that measurement of IL6 as well as albumin, rather than the MPI score, may help in providing tailored therapeutic interventions to decrease short term mortality in older hospitalized individuals