859 research outputs found
Reliable Peer-to-Peer Access for Italian Citizens to Digital Government Services on the Internet
In the delivery of e-government services to citizens it should be clear that the viewpoint cannot simply be the standard one of client-supplier commonly used to provide services on the Internet. In a modern society it has rather to be the peer-to-peer approach which is typical of democracies, where institutions are equal to citizens in front of the law. But this is not yet a widely accepted standpoint in digital government efforts going on in many advanced countries in the world.
Italian government, in its ever increasing effort to provide citizens with easier access to online government services, has instead adopted and is pursuing this symmetric approach, which is going to represent a fundamental tool in the ongoing march towards e-democracy.
In this paper we describe the organizations involved in the process and the Information Technology (IT) infrastructure enabling the effective management of the whole process while ensuring the mandatory security functions in a democratic manner. Organizational complexity lies in the distribution of responsibilities for the management of people’s personal data among the more than 8000 Italian Municipalities and the need of keeping a centralized control on all processes dealing with identity of people.
Technical complexity stems from the need of efficiently supporting this distribution of responsibilities while ensuring, at the same time, interoperability of IT-based systems independent of technical choices of the organizations involved, and fulfillment of privacy constraints. The IT architecture defined for this purpose features a clear separation between security services, provided at an infrastructure level, and application services, exposed on the Internet as Web Services
Exploring different methods of cellulose extraction for 14C dating
In this study we aim to identify the optimal cellulose extraction protocol for 14C dating of wood, with a focus on glacial trees. To achieve this, we compare three cellulose extraction methods on the basis of cellulose yield and 14C age. The study is conducted on 12 wood samples of different species, in varying states of preservation with ages covering the full 14C age range. Cellulose is extracted from each sample following three different protocols selected from the literature: ABA-B, BABAB and 2Chlorox. The extracted cellulose was graphitised and dated with the MICADAS (Mini Carbon Dating System) at the ETH AMS laboratory. Although all three methods are considered efficient, the BABAB protocol, despite being a more aggressive procedure, allows the extraction of a sufficient amount of cellulose to be 14C dated and leads to the most reliable results, particularly for very old and background samples (samples with 14C content of zero)
Algorithms for the on-line travelling salesman
In this paper the problem of efficiently serving a sequence of requests presented in an on-line fashion located at points of a metric space is considered. We call this problem the On-Line Travelling Salesman Problem (OLTSP). It has a variety of relevant applications in logistics and robotics. We consider two versions of the problem. In the first one the server is not required to return to the departure point after all presented requests have been served. For this problem we derive a lower bound on the competitive ratio of 2 on the real line. Besides, a 2.5-competitive algorithm for a wide class of metric spaces, and a 7/3-competitive algorithm for the real line are provided. For the other version of the problem, in which returning to the departure point is required, we present an optimal 2-competitive algorithm for the above mentioned general class of metric spaces. If in this case the metric space is the real line we present a 1.75-competitive algorithm that compares with a \approx 1.64 lower bound
The molecular chaperone Hsp90 is a component of the cap-binding complex and interacts with the translational repressor Cup during Drosophila oogenesis
In metazoa, the spatio-temporal translation of diverse mRNAs is essential to guarantee proper oocyte maturation and early embryogenesis. The eukaryotic translation initiation factor 4E (eIF4E), which binds the 5′ cap structure of eukaryotic mRNAs, associates with either stimulatory or inhibitory factors to modulate protein synthesis. In order to identify novel factors that might act at the translational level during Drosophila oogenesis, we have undertaken a functional proteomic approach and isolated the product of the Hsp83 gene, the evolutionarily conserved chaperone Hsp90, as a specific component of the cap-binding complex. Here we report that Hsp90 interacts in vitro with the translational repressor Cup. In addition, we show that Hsp83 and cup interact genetically, since lowering Hsp90 activity enhances the oogenesis alterations linked to diverse cup mutant alleles. Hsp90 and Cup co-localize in the cytoplasm of the developing germ-line cells within the germarium, thus suggesting a common function from the earliest stages of oogenesis. Taken together, our data start elucidating the role of Hsp90 during Drosophila female germ-line development and strengthen the idea that Cup has multiple essential functions during egg chamber development
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Saving old bones: A non-destructive method for bone collagen prescreening
Bone collagen is an important material for radiocarbon, paleodietary, and paleoproteomic analyses, but it degrades over time, making such analyses more difficult with older material. Collagen preservation between and within archaeological sites is also variable, so that much time, effort, and money can go into the preparation and initial analysis of samples that will not yield meaningful results. To avoid this, various methods are employed to prescreen bone for collagen preservation (e.g., %N, microporosity, and FTIR spectroscopic analyses), but these are often destructive and/or require exportation for analysis. Here, we explore near-infrared spectroscopy as a tool for gauging the collagen content of ground and whole bone from about 500 to 45,000 years ago. We show that a portable spectrometer’s ability to quantify collagen content and classify specimens by preservation status is comparable to that of other popular prescreening methods. Moreover, near-infrared spectroscopy is non-destructive and spectra can be acquired in a few seconds
A targeted drilling and dating campaign to identify Stone Age archaeological sites before excavation in west coast southern Africa
Here we present the results of a targeted drilling campaign that facilitated a geochronological study with coarse
sampling resolution inside a new cave site, Simons Cave, on the west coast of southern Africa. A combination of
radiocarbon (14C) dating and optically stimulated luminescence (OSL) dating was used as a range-finder. Results
confirmed preservation of Holocene and late Pleistocene sediments up to 133 ± 35 ka, overlapping with the ages
of Middle Stone Age (MSA) occupations of the broader west coast region. A subsequent, systematic test-
excavation at the site then embarked on a second geochronological study with a higher sampling resolution.
Ultimately, the comparative study confirmed the potential of Simons Cave as a new site for the exploration of
hominin occupation through the later Pleistocene and Holocene, yet raised several issues concerning the direct
comparability of information deriving from drilled sediment cores and actual archaeological excavation
The Tien Shan vole (Microtus ilaeus; Rodentia: Cricetidae) as a new species in the Late Pleistocene of Europe
Abstract Grey voles (subgenus Microtus) represent a complex of at least seven closely related and partly cryptic species. The range of these species extends from the Atlantic to the Altai Mountains, but most of them occur east of the Black Sea. Using ancient DNA analyses of the Late Pleistocene specimens, we identified a new mtDNA lineage of grey voles in Europe. Phylogenetic analysis of mitochondrial DNA cytochrome b sequences from 23 voles from three caves, namely, Emine?Bair?Khosar (Crimea, Ukraine), Cave 16 (Bulgaria), and Bacho Kiro (Bulgaria), showed that 14Â specimens form a previously unrecognized lineage, sister to the Tien Shan vole. The average sequence divergence of this lineage and the extant Tien Shan vole was 4.8%, which is similar to the divergence of grey vole forms, which are considered distinct species or being on the verge of speciation; M. arvalis and M. obscurus or M. mystacinus and M. rossiaemeridionalis. We estimated the time to the most recent common ancestor of the grey voles to be 0.66Â Ma, which is over twice the recent estimates, while the divergence of the extant Tien Shan vole and the new lineage to be 0.29Â Ma. Our discovery suggests that grey voles may have been more diversified in the past and that their ranges may have differed substantially from current ones. It also underlines the utility of ancient DNA to decipher the evolutionary history of voles
Is there Initial Upper Palaeolithic in Western Tian Shan? Example of an open-air site Katta Sai 2 (Uzbekistan)
The paper presents the results of multidisciplinary studies on the open-air loess site Katta Sai 2 located in thewestern piedmonts of Tian Shan in Uzbekistan. Two archaeological horizons contain features associated with theInitial Upper Palaeolithic (IUP) - both Levallois and blade/bladelet volumetric technology, together with anUpper Palaeolithic toolkit. The cultural traits observed in Katta Sai 2 might have local roots dating back to MIS 5aand can be found in so-called Obirakhmatian technocomplex determined in several archaeological sites in theregion. Thus, the obtained results question the hypothesis of non-local origins of IUP complexes associated withthe early modern human migration from the Near East to Mongolia along the piedmonts of Pamir and Tian Shan.Until reliable anthropological and genetic data are obtained, it seems to be too early to conclude about therelationship between modern human migration and the appearance of IUP assemblages, at least across thewestern parts of Central Asia
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