Optical Clocks in Space

The performance of optical clocks has strongly progressed in recent years, and accuracies and instabilities of 1 part in 10^18 are expected in the near future. The operation of optical clocks in space provides new scientific and technological opportunities. In particular, an earth-orbiting satellite containing an ensemble of optical clocks would allow a precision measurement of the gravitational redshift, navigation with improved precision, mapping of the earth's gravitational potential by relativistic geodesy, and comparisons between ground clocks.Comment: Proc. III International Conference on Particle and Fundamental Physics in Space (SpacePart06), Beijing 19 - 21 April 2006, to appear in Nucl. Phys.

Helicobacter pylori primary and secondary genotypic resistance to clarithromycin and levofloxacin detection in stools: A 4-year scenario in Southern Italy

Antibiotic resistance has become an emerging problem for treating Helicobacter pylori (H. pylori) infection. Clarithromycin and levofloxacin are two key antibiotics used for its eradication. Therefore, we reviewed our experience with genotypic resistance analysis in stools to both clarithromycin and levofloxacin in the last four years to evaluate time trends, both in naive and failure patients. Patients collected a fecal sample using the THD fecal test device. Real-time polymerase chain reaction was performed to detect point mutations conferring resistance to clarithromycin (A2142C, A2142G, and A2143G in 23S rRNA) and levofloxacin (substitutions at amino acid position 87 and 91 of gyrA). One hundred and thirty-five naive patients were recruited between 2017-2020. Clarithromycin resistance was detected in 37 (27.4%). The time trend did not show any significant variation from 2017 to 2020 (p = 0.33). Primary levofloxacin resistance was found in 26 subjects (19.2%), and we observed a dramatic increase in rates from 2017 (10%) to 2018 (3.3%), 2019 (20%), and 2020 (37.8%). Ninety-one patients with at least one eradication failure were recruited. Secondary resistance to clarithromycin and levofloxacin was found in 59 (64.8%) and 45 patients (59.3%), respectively. In conclusion, our geographic area has a high risk of resistance to clarithromycin. There is also a progressive spreading of levofloxacin-resistant strains

A Web-based spatial decision supporting system for land management and soil conservation

Abstract. Today it is evident that there are many contrasting demands on our landscape (e.g. food security, more sustainable agriculture, higher income in rural areas, etc.) as well as many land degradation problems. It has been proved that providing operational answers to these demands and problems is extremely difficult. Here we aim to demonstrate that a spatial decision support system based on geospatial cyberinfrastructure (GCI) can address all of the above, so producing a smart system for supporting decision making for agriculture, forestry, and urban planning with respect to the landscape. In this paper, we discuss methods and results of a special kind of GCI architecture, one that is highly focused on land management and soil conservation. The system allows us to obtain dynamic, multidisciplinary, multiscale, and multifunctional answers to agriculture, forestry, and urban planning issues through the Web. The system has been applied to and tested in an area of about 20 000 ha in the south of Italy, within the framework of a European LIFE+ project (SOILCONSWEB). The paper reports – as a case study – results from two different applications dealing with agriculture (olive growth tool) and environmental protection (soil capability to protect groundwater). Developed with the help of end users, the system is starting to be adopted by local communities. The system indirectly explores a change of paradigm for soil and landscape scientists. Indeed, the potential benefit is shown of overcoming current disciplinary fragmentation over landscape issues by offering – through a smart Web-based system – truly integrated geospatial knowledge that may be directly and freely used by any end user (www.landconsultingweb.eu). This may help bridge the last very important divide between scientists working on the landscape and end users

New miniaturized microwave cavity for Rubidium atomic clocks

Nowadays there is an increasing need for radically miniaturized and low-power atomic frequency standards, for use in mobile and battery-powered applications. For the miniaturization of double-resonance (DR) Rubidium (Rb-87) atomic clocks, the size reduction of the microwave cavity or resonator (MWR) to well below the wavelength of the atomic transition (6.835 GHz for Rb-87) has been a long-standing issue. Here we present a newly developed miniaturized MWR, the mu-LGR, consisting of a loop-gap resonator based cavity with very compact dimensions (volume < 0.9 cm(3)). The mu-LGR meets the requirements of the atomic clock application and its assembly can be performed using repeatable and low-cost techniques. The concept of the proposed device was validated through simulations and prototypes were successfully manufactured and tested. High-quality DR spectra and first clock stabilities were demonstrated experimentally, proving that the mu-LGR is suitable for integration in a miniaturized atomic clock

From theory to the complex geospatial ground-truth of contaminated soils.

Characterization and subsequent reclamation of contaminated sites require detailed knowledge of the geospatial distribution of contamination. In Italy, a potentially contaminated site is an area where the concentration of one or more contaminants in soils is above land-use legal limits (CSC according to Italian law 152/06). Four main phases have to be followed to assess contamination and then reclamation: 1) preliminary conceptual model, 2) characterization plan, 3) site specific risk analysis (by Risk-net software) setting the contamination threshold concentration (CSR), 4) assessment of contamination and therefore reclamation action by comparison between CSC and CSR. The geospatial distribution of contaminants is considered in the characterization plan. It is mandatory to sample at least three samples for each surveyed point (one sample in the 0 to 1 m depth, one sample in the capillary fringe zone and one in between). There aren’t clear indications on the sampling strategy and spatial density. According to Italian law (D.M. 471/99), it is usual to identify 5 to 15 sampling points for areas of 1 to 5 hectares. In this work we attempt to answer the question: “After more than a decade from the introduction of law 152/06 and considering the progress of scientific knowledge, are these soil sampling criteria suitable for assessing the spatial and volumetric distribution of site contamination? We considered the analytical and spatial dataset obtained from two rural and industrial potentially polluted sites of south Italy, formerly interested by past disposal of industrial sludge and wastes. In both sites results showed that: (i) the geospatial variability of contamination is always much more complex than expected and depends by the history of the contamination; (ii) the sampling of the first meter - as a single body - is not satisfactory because it does not take into account the real vertical distribution of pollutants and the soil stratigraphy (such as the presence of centimeter horizons). The work illustrates the use of proximal sensing sensors, such as EMI, ARP, portable gamma-ray spectrometers and portable XRFs to obtain detailed mappings for homogeneous areas identification, where to address subsequent pedological and chemical investigations. Moreover, the pedological observation - guided by these technologies - often provides essential information to understand the process of emplacement and possible migration of pollutants towards other environmental sectors. The applied integrated approach, which was found very relevant for the site characterization, can assume even greater importance in the subsequent phase of reclamation

Expanding Social Science Through Disaster Studies

Objectives. This article provides an overview of how the interdisciplinary field of disaster studies contributes to the social sciences. Methods. The following themes are explored in relation to the articles contained in the special issue: disasters are social and political phenomena that generate policy change, disasters reflect and affect democratic governance, and disasters reveal shared experience and collective identity. Results. Disaster studies bridge the social sciences theoretically and methodologically. Given the scope of disaster impacts—across social, political, economic, ecological, and infrastructure spheres—and the policy response they garner involving public, private, and civic actors, they offer a lens by which to see society and politics in a way that no other critical events can. Conclusion. Disaster studies offer important applications of social science theories and concepts that expand the field, broaden our reach as social scientists, and deepen our understanding of fundamental social processes and behaviors in meaningful ways

Roadmap towards the redefinition of the second

This paper outlines the roadmap towards the redefinition of the second, which was recently updated by the CCTF Task Force created by the CCTF in 2020. The main achievements of optical frequency standards (OFS) call for reflection on the redefinition of the second, but open new challenges related to the performance of the OFS, their contribution to time scales and UTC, the possibility of their comparison, and the knowledge of the Earth's gravitational potential to ensure a robust and accurate capacity to realize a new definition at the level of 10-18 uncertainty. The mandatory criteria to be achieved before redefinition have been defined and their current fulfilment level is estimated showing the fields that still needed improvement. The possibility to base the redefinition on a single or on a set of transitions has also been evaluated. The roadmap indicates the steps to be followed in the next years to be ready for a sound and successful redefinition