Winter survival of microbial contaminants in soil: an in situ verification.

The aim of the research was to evaluate, at site scale, the influence of freezing and freeze/thaw cycles on the survival of faecal coliforms and faecal enterococci in soil, in a climate change perspective. Before the winter period and during grazing, viable cells of faecal coliforms and faecal enterococci were detected only in the first 10 cm below ground, while, after the winter period and before the new seasonal grazing, a lower number of viable cells of both faecal indicators was detected only in some of the investigated soil profiles, and within the first 5 cm. Taking into consideration the results of specific investigations, we hypothesise that the non-uniform spatial distribution of grass roots within the studied soil can play an important role in influencing this phenomenon, while several abiotic factors do not play any significant role. Taking into account the local trend in the increase of air temperature, a different distribution of microbial pollution over time is expected in spring waters, in future climate scenarios. The progressive increase in air temperature will cause a progressive decrease in freeze/thaw cycles at higher altitudes, minimising cold shocks on microbial cells, and causing spring water pollution also during winter.

Environmental drivers of dynamic soil erosion change in a Mediterranean fluvial landscape.

BACKGROUND: Rainfall and other climatic agents are the main triggers of soil erosion in the Mediterranean region, where they have the potential to increase discharge and sediment transport and cause long-term changes in the river system. For the Magra River Basin (MRB), located in the upper Tyrrhenian coast of Italy, we estimated changes in net erosion as a function of the geographical characteristics of the basin, the seasonal distribution of precipitation, and the vegetation cover. METHODS AND FINDINGS: Based on rainfall erosivity and surface flow and transport sub-models, we developed a simplified model to assess basin-wide sediment yields on a monthly basis by upscaling the point rainfall input. Our calibration dataset of monthly data (Mg km-2 month-1, available for the years 1961 and 1963-1969) revealed that our model satisfactorily reproduces the net soil erosion in the study area (R2 = 0.81). For the period 1950-2020, the reconstruction of an annually aggregated time-series of monthly net erosion data (297 Mg km-2 yr-1 on average) indicated a moderate decline in sediment yield after 1999. This is part of a long-term downward trend, which highlights the role played by land-use changes and reforestation of the mountainous areas of the basin. CONCLUSION: This study shows the environmental history and dynamics of the basin, and thus the varying sensitivity of hydrological processes and their perturbations. Relying on a few climatic variables as reported from a single representative basin location, it provides an interpretation of empirically determined factors that shape active erosional landscapes. In particular, we showed that the most recent extreme storms associated with sediment yield have been characterised by lower cumulative rainfall, indicating a greater propensity for the basin to produce sediment more discontinuously over time.

Hydro-climatic forcing of dissolved organic carbon in two boreal lakes of Canada.

The boreal forest of the northern hemisphere represents one of the world's largest ecozones and contains nearly one third of the world's intact forests and terrestrially stored carbon. Long-term variations in temperature and precipitation have been implied in altering carbon cycling in forest soils, including increased fluxes to receiving waters. In this study, we use a simple hydrologic model and a 40-year dataset (1971-2010) of dissolved organic carbon (DOC) from two pristine boreal lakes (ELA, Canada) to examine the interactions between precipitation and landscape-scale controls of DOC production and export from forest catchments to surface waters. Our results indicate that a simplified hydrologically-based conceptual model can enable the long-term temporal patterns of DOC fluxes to be captured within boreal landscapes. Reconstructed DOC exports from forested catchments in the period 1901-2012 follow largely a sinusoidal pattern, with a period of about 37years and are tightly linked to multi-decadal patterns of precipitation. By combining our model with long-term precipitation estimates, we found no evidence of increasing DOC transport or in-lake concentrations through the 20th century.

Storminess and geo-hydrological events affecting small coastal basins in a terraced Mediterranean environment.

This study was prompted by the occurrence of an extreme Damaging geo-Hydrological Event (DHE) which occurred on October 25th 2011 and which affected a wide area of the northern Mediterranean region. After analysing the storm by means of the precipitation time series, the study attempts to relate the October 25th 2011 DHE with a series of other DHEs that occurred in the period 1954-2012, assessed via the use of historical data and classified according to severity, with a Storm Erosivity Indicator (Ra). The annual mean of the Ra value (2582 MJ mm ha(-1) h(-1) y(-1)) confirmed that the study area is one of the European regions with the highest rainfall erosivity level. A shift in storminess during 1991-2012 with respect to 1954-1990 was observed. A return period of 1000 years was calculated for the single storm erosivity of October 25th, which contributed to 84% of the total annual storm erosivity of 2011 A quite good agreement was found comparing DHE distribution and severity with Ra anomalies over time. As a matter of fact, most of the low severity DHEs (62.5%) occurred in years in which the Ra was below the average value. Moreover, almost all DHEs (93%) ranging from medium- to very high-severity occurred in years for which the Ra exceeded the average value. With regard to the occurrence of the most severe DHE classes, a threshold of the Ra and a recurrence time of approximately 3300 MJ mm ha(-1) h(-1) y(-1) and 12 years, respectively, were identified. Finally, some evidences suggest that an increasing frequency of DHEs is expected in the forthcoming years. It is argued that understanding these issues is a major priority for future research in order to improve land and urban planning strategies for preserving people and the environment, leading ultimately to an effective risk reduction.

Retrospective and observational study to assess the efficacy of citicoline in elderly patients suffering from stupor related to complex geriatric syndrome.

A significant percentage of elderly subjects (50%-80%) suffering from sub-acute ischemic cerebrovascular disease, with or without moderate or severe cognitive memory decline and with or without associated behavioral and psychological symptoms, shows a complex syndrome. This syndrome is related to the progressive impairment of health conditions and/or stressing events (ie, hospitalization), characterized by confusion and/or stupor, which are consequently difficult to manage and require a great deal of care. Geriatric patients often suffer from multiple chronic illnesses, may take numerous medications daily, exhibit clinical instability, and may experience worsening of medical conditions following cerebral ischemic events and thus have an increased risk of disability and mortality. There are several studies in literature which demonstrate the efficacy of citicoline, thanks to its neuroprotective function, for the recovery and in postischemic cerebral rehabilitation. It has been shown that, even soon after an ischemic stroke, administration of oral citicoline (500-4000 mg/day) improves the general conditions evaluated with the Rankin scale and the National Institute of Health Stroke Scale 12. In particular, it has been shown that the CDP-choline improves the cognitive and mental performance in Alzheimer's dementia and vascular dementia. We have evaluated the administration of citicoline in geriatric patients following a protocol of intravenous study on improvement of individual performances.

Effects of demographic and environmental variables on cognitive performance in a rural community sample of elderly people living in Southern Italy.

BACKGROUND AND AIMS: The aim of our study was to understand how demographic and environmental factors may be associated with cognitive functions in a rural population of Southern Italy, with a very high percentage of elderly persons with little formal education. MATERIALS AND METHODS: From the population registry of San Marcellino (province of Caserta), out of 1089 persons aged over 60 years, a random sample of 300 residents received a door-to-door visit. Two hundred and twenty-six subjects were judged as not having significant cognitive impairment, on the basis of their personal history and Clinical Dementia Rating score (< 1). They were administered the Mini Mental State Examination (MMSE). RESULTS: A positive statistically significant correlation was observed between MMSE score and education, but not between MMSE score, age and gender. Normative data showed that 90% of the normal population from this area had an adjusted MMSE score of more than 16.20, a value far below the traditional cut-off score of 23/24 for diagnosis of dementia. Subjects living with their families showed better performance than persons living alone or only with spouses. CONCLUSIONS: This finding is consistent with other epidemiologic surveys, and suggests the possible role of ecological and environmental factors in preventing or compensating cognitive decline, at least in persons coming from homogeneous rural areas. Low social demands in a protective family environment do not stimulate high intellectual performance, and signs of dementia may not be recognized by persons living in this context until the patient reaches a severe stage of disease.