221 research outputs found

    Fast geophysical prospecting applied to archaeology: results at «Villa ai Cavallacci» (Albano Laziale, Rome) site

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    The present essay is the result of a cooperative work between geophysicists and archaeologists in which the authors carried out an integrated geophysical prospecting in an archaeological site near Rome. This paper describes the methodology and the results of a geophysical survey carried out on Villa ai Cavallacci, an ancient roman building in Albano Laziale (Rome) discovered in the late seventies. It is often possible to obtain very important results planning a fast geophysical survey opportunely; within this framework (due to the fact that an archaeological excavation was planned in a short time), an integrated geophysical techniques survey (GPR, magnetic, and geoelectric tomography) has been carried out on the areas indicated by the archaeologists. Even if the described geophysical survey should be considered only a first step analysis, the data pointed out some very interesting features confirmed by the excavation

    Performance of nonparametric species richness estimators in a high diversity plant community

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    The efficiency of four nonparametric species richness estimators - first-order Jackknife, second-order Jackknife, Chao2 and Bootstrap - was tested using simulated quadrat sampling of two field data sets (a sandy 'Dune' and adjacent 'Swale') in high diversity shrublands (kwongan) in south-western Australia. The data sets each comprised > 100 perennial plant species and < 10 000 individuals, and the explicit (x-y coordinate) location of every individual. We applied two simulated sampling strategies to these data sets based on sampling quadrats of unit sizes 1/400th and 1/100th of total plot area. For each site and sampling strategy we obtained 250 independent sample curves, of 250 quadrats each, and compared the estimators' performances by using three indices of bias and precision: MRE (mean relative error), MSRE (mean squared relative error) and OVER (percentage overestimation). The analysis presented here is unique in providing sample estimates derived from a complete, field-based population census for a high diversity plant community. In general the true reference value was approached faster for a comparable area sampled for the smaller quadrat size and for the swale field data set, which was characterized by smaller plant size and higher plant density. Nevertheless, at least 15-30% of the total area needed to be sampled before reasonable estimates of St (total species richness) were obtained. In most field surveys, typically less than 1% of the total study domain is likely to be sampled, and at this sampling intensity underestimation is a problem. Results showed that the second-order Jackknife approached the actual value of St more quickly than the other estimators. All four estimators were better than Sobs (observed number of species). However, the behaviour of the tested estimators was not as good as expected, and even with large sample size (number of quadrats sampled) all of them failed to provide reliable estimates. First- and second-order Jackknives were positively biased whereas Chao2 and Bootstrap were negatively biased. The observed limitations in the estimators' performance suggests that there is still scope for new tools to be developed by statisticians to assist in the estimation of species richness from sample data, especially in communities with high species richness

    Epiphytic lichens of the sacred natural site &quot;Bosco di Sant&apos;Antonio&quot; (Majella National Park - Abruzzo)

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    Sacred Natural Sites are relevant for biodiversity conservation, as in the case of forest sites that, across centuries, developed old growth structures and are now crucial for the conservation of epiphytic lichens and other specialized forest organisms. In this study, we investigated the epiphytic lichen flora of a small forest patch included in the Majella National Park (Abruzzo), whose old growth features and naturalness reflect its long lasting spiritual role that perfectly fits with the concept of Sacred Natural Site. Results revealed that the "Bosco di Sant'Antonio" hosts a rich and interesting epiphytic lichen flora, thus indicating the potential of this Sacred Natural Site for lichen conservation. Fifty-six species were found including two species newly recorded in Abruzzo, two red-listed species, and the sensitive species Lobaria pulmonaria. This study corroborates the hypothesis that sacred forest sites are relevant for the conservation of specialized epiphytic lichens. In particular, in the Italian forest landscape where old-growth stands are practically absent, sacred forest sites may provide unique old-growth structures and buffer anthropogenic disturbance

    Evaluation of trace calls by Xpert MTB/RIF ultra for clinical management in low TB burden settings

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    Background Clinical interpretation of trace results by Xpert MTB/RIF Ultra assay (Ultra) used as an initial diagnostic test for tuberculosis (TB) may be challenging. The aim of the study was to evaluate the frequency and epidemiology of trace readouts in routine clinical practice in a low TB prevalence setting and to propose guidance on how to manage patients with trace calls considering the data available (clinical, radiological, bacteriological etc.). Materials and methods A retrospective, observational, monocentric study was conducted at IRCCS Azienda Ospedaliero-Universitaria of Bologna, Italy between November 2017—December 2020. Presumptive TB patients with at least one Ultra trace result during diagnostic workup before treatment were included in the study. Patients with ongoing anti-TB treatment at the time of the trace call result or with no clinical data available were excluded from the study. Results Fifty-nine presumptive TB patients with Ultra trace readouts were included in the study (mean age 37.0 years, 61% males). Four patients had a history of TB in the last 2 years. Twenty-five (42.4%) of the 59 samples with trace results were respiratory material. 57/59 (96.6%) patients started anti-TB treatment soon after obtaining trace results, based on clinical, radiological or other information available, while for two patients with a recent history of TB the trace result did not lead to anti-TB treatment. Culture was positive for M. tuberculosis for 31/59 (52.5%) samples with trace calls: 13/25 (52.0%) were respiratory samples and 18/33 (54.5%) non-respiratory samples. The clinical and/or radiological findings of 47/57 (82.4%) patients given anti-TB therapy improved during treatment. Conclusion In low TB incidence settings, Ultra trace calls in presumptive TB patients should be considered as true-positive and treatment should be started promptly, except in cases of recent history of TB, where careful evaluation of other diagnostic criteria is necessary before starting anti-TB treatment. A decisional algorithm for clinical management is proposed

    Fast geophysical prospecting applied to archaeology: results at «Villa ai Cavallacci» (Albano Laziale, Rome) site

    Get PDF
    The present essay is the result of a cooperative work between geophysicists and archaeologists in which the authors carried out an integrated geophysical prospecting in an archaeological site near Rome. This paper describes the methodology and the results of a geophysical survey carried out on Villa ai Cavallacci, an ancient roman building in Albano Laziale (Rome) discovered in the late seventies. It is often possible to obtain very important results planning a fast geophysical survey opportunely; within this framework (due to the fact that an archaeological excavation was planned in a short time), an integrated geophysical techniques survey (GPR, magnetic, and geoelectric tomography) has been carried out on the areas indicated by the archaeologists. Even if the described geophysical survey should be considered only a first step analysis, the data pointed out some very interesting features confirmed by the excavation

    Fast geophysical prospecting applied to archaeology: results at “Villa ai Cavallacci” (Albano Laziale, Rome) site

    Get PDF
    The present essay is the result of a cooperative work between geophysicists and archaeologists in which the authors carried out an integrated geophysical prospecting in an archaeological site near Rome. In this paper it is described the methodology and the results of a geophysical survey carried out on Villa ai Cavallacci, an ancient roman building in Albano Laziale (Rome) discovered towards the late seventies. It is often possible to obtain very important results planning a fast geophysical survey opportunely; within this framework (due to the fact that an archaeological excavation was planned in a little time), an integrated geophysical techniques survey (GPR, magnetic, and geoelectric tomography) has been carried out on the areas indicated by the archaeologists. Even if the described geophysical survey should be considered only a first step analysis, the data pointed out some very interesting features confirmed by the excavation

    Investigating elevational gradients of species richness in a Mediterranean plant hotspot using a published flora

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    The Apuan Alps are one of the most peculiar mountain chain in the Mediterranean, being very close to the coastline and reaching an elevation of almost 2000 m. Based on published flora, we investigated the distribution of plant species richness along the whole elevational gradient of this chain considering: (i) all species, (ii) endemic versus alien species; and (iii) functional groups of species based on Raunkiær life forms (RLF). Generalized Linear Models (GLMs) were used to analyse richness patterns along the elevational gradient, and elevational richness models versus the area of the elevational belts were fitted to test the effect of surface area. Our results showed decreasing species richness with increasing elevation. In contrast, endemic species richness increased along the elevational gradient. Alien species were mainly distributed at low elevations, but this result should be taken with caution since we used historical data. Species life forms were not equally distributed along the elevation gradient: chamaephytes and hemicryptophytes were the richest groups at high elevations, while therophytes showed highest species richness at low elevations. Our findings suggest that in the Apuan Alps there is a major elevational gradient in species composition that could reflect plant evolutionary history. Furthermore, we highlight the key role of published floras as a relevant source of biodiversity data.publishedVersio

    Probabilistic and preferential sampling approaches offer integrated perspectives of Italian forest diversity

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    Aim: Assessing the performances of different sampling approaches for documenting community diversity may help to identify optimal sampling efforts and strategies, and to enhance conservation and monitoring planning. Here, we used two data sets based on probabilistic and preferential sampling schemes of Italian forest vegetation to analyze the multifaceted performances of the two approaches across three major forest types at a large scale. Location: Italy. Methods: We pooled 804 probabilistic and 16,259 preferential forest plots&nbsp;as&nbsp;samples&nbsp;of&nbsp;vascular&nbsp;plant&nbsp;diversity across the country. We balanced the two data sets in terms of sizes, plot size, geographical position, and vegetation types. For each of the two data sets, 1000 subsets of 201 random plots were compared by calculating the shared and exclusive indicator species, their overlap in the multivariate space, and the areas encompassed by spatially-constrained rarefaction curves. We then calculated an index of performance using the ratio between the additional and total information collected by each sampling approach. The performances were tested and evaluated across the three major forest types. Results: The probabilistic approach performed better in estimating species richness and diversity of species assemblages, but did not detect other components of the regional diversity, such as azonal forests. The preferential approach outperformed the probabilistic approach in detecting forest-specialist species and plant diversity hotspots. Conclusions: Using a novel workflow based on vegetation-plot exclusivities and commonalities, our study suggests probabilistic and preferential sampling approaches are to be used in combination for better conservation and monitor planning purposes to detect multiple aspects of plant community diversity. Our findings can assist the implementation of national conservation planning and large-scale monitoring of biodiversity

    Forest ecosystem monitoring in Tuscany (Italy): past activities, present status and future perspectives

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    Since 1987 the Region of Tuscany has been actively monitoring crown status in its forests, in order to protect them from atmospheric pollution, biotic factors and environmental change. Over this period the Region has performed periodical inventories on crown condition in publicly-owned forests (Level I network) and established a network of permanent plots (MON.I.TO., Level II – III) to study long-term changes occurring in forest ecosystems. Some of these permanent plots were later included in the national programme CONECOFOR, managed by the Ministry for Policy in Agriculture and Forest. Currently a further development of MON.I.TO. is being implemented, called MONITO III – TOpModel, the aim of which is to broaden the information potential of the monitoring system to include carbon stocks and biodiversity evaluation. This paper provides an up-to-date report on the status of the various surveys and recommends a closer connection between MON.I.TO. and the other regional information systems, especially the Regional Forest Inventory, in order to produce information that may be useful in forest planning and in Sustainable Forest Management
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