Bureaucratic competence and procurement outcomes

To what extent does a more competent public bureaucracy contribute to better economic outcomes? We address this question in the context of the US federal procurement of services and works, by combining contract-level data on procurement performance and bureau-level data on competence and workforce characteristics. We use the death occurrences of specific types of employees as instruments and find that an increase in bureau competence causes a significant and economically important reduction in: i) time delays, ii) cost overruns, and iii) number of renegotiations. Cooperation within the office appears to be a key driver of the findings

Thermally-Reconfigurable Quantum Photonic Circuits at Telecom Wavelength by Femtosecond Laser Micromachining

The importance of integrated quantum photonics in the telecom band resides on the possibility of interfacing with the optical network infrastructure developed for classical communications. In this framework, femtosecond laser written integrated photonic circuits, already assessed for quantum information experiments in the 800 nm wavelength range, have great potentials. In fact these circuits, written in glass, can be perfectly mode-matched at telecom wavelength to the in/out coupling fibers, which is a key requirement for a low-loss processing node in future quantum optical networks. In addition, for several applications quantum photonic devices will also need to be dynamically reconfigurable. Here we experimentally demonstrate the high performance of femtosecond laser written photonic circuits for quantum experiments in the telecom band and we show the use of thermal shifters, also fabricated by the same femtosecond laser, to accurately tune them. State-of-the-art manipulation of single and two-photon states is demonstrated, with fringe visibilities greater than 95%. This opens the way to the realization of reconfigurable quantum photonic circuits on this technological platform

Roca Archaeological Survey: Inquadramento e primissimi risultati

Mobility and interaction have been primarily analysed from the vantage point of the archaeological sites representing the main hubs of interaction. However, such hubs were always immersed in a continuous landscape which had a considerable effect on interaction dynamics. An effect that has started to be taken in due consideration only recently.The Roca Archaeological Survey, of which we here present the first preliminary results, tries to integrate our detailed knowledge based on excavations of the site of Roca Vecchia in Apulia, with a systematic multi-period surface investigation able to assess whether and to what extent the surrounding landscape has affected dynamics of interaction recognised in the main site from the bronze age to modern time

Roca archaeological survey : inquadramento e primissimi risultati

Mobility and interaction have been primarily analysed from the vantage point of the archaeological sites representing the main hubs of interaction. However, such hubs were always immersed in a continuous landscape which had a considerable effect on interaction dynamics. An effect that has started to be taken in due consideration only recently. The Roca Archaeological Survey, of which we here present the first preliminary results, tries to integrate our detailed knowledge based on excavations of the site of Roca Vecchia in Apulia, with a systematic multi-period surface investigation able to assess whether and to what extent the surrounding landscape has affected dynamics of interaction recognised in the main site from the bronze age to modern times

Doubly resonant photoacoustic spectroscopy: ultra-high sensitivity meets ultra-wide dynamic range

Photoacoustic spectroscopy (PAS) based gas sensors with high sensitivity, wide dynamic range, low cost, and small footprint are desirable across a broad range of applications in energy, environment, safety, and public health. However, most works have focused on either acoustic resonator to enhance acoustic wave or optical resonator to enhance optical wave. Herein, we develop a gas sensor based on doubly resonant PAS in which the acoustic and optical waves are simultaneously enhanced using combined optical and acoustic resonators in a centimeter-long configuration. Not only the lower detection limit is enhanced by the double standing waves, but also the upper detection limit is expanded due to the short resonators. As an example, we developed a sensor by detecting acetylene (C2H2), achieving a noise equivalent absorption of 5.7*10-13 cm-1 and a dynamic range of eight orders. Compared to the state-of-the-art PAS gas sensors, the developed sensor increases the sensitivity by two orders of magnitude and extends the dynamic range by three orders of magnitude. Besides, a laser-cavity-molecule locking strategy is proposed to provide additional flexibility of fast gas detection

Middle Palaeolithic technical behaviour: Material import-export and Levallois production at the SU 13 of Oscurusciuto rock shelter, Southern Italy

The Oscurusciuto rock shelter, located in southern Italy (Puglia), has yielded a long Middle Palaeolithic stratigraphy rich in lithic assemblages, fireplaces and faunal remains, attesting Neanderthal occupation during the MIS 3. This paper is focused on the stratigraphic unit 13, consisting of a sandy compact deposit mixed with pyroclastic sediment above a thick level of tephra-US 14, identified as Mt. Epomeo green tuff (dated Ar/Ar ~ 55 ka).Level 13 represents the first stable human occupation after the deposition of tephra. Our goal was to examine the lithic assemblage of this stratigraphic unit by means of an interdisciplinary approach (technology, RMU, refitting program) in order to identify the economic behaviour and technical strategies of Neanderthals occupying the stratigraphic unit 13 of Oscurusciuto.The technical strategies applied indicate fragmentation of the reduction processes, as well as probable events of importation and exportation of objects. The lithic material were introduced at different stages of manufacturing. Pieces were introduced in the form of rough objects (pebbles), as well as semi-finished items, and as finished tools. This fragmentation of the chaîne opératoire also demonstrate the palimpsest nature of the level which is made up of different events happening one after another.The main concept of debitage was Levallois, generally realized on local jasper and siliceous limestone pebbles or cortical flakes. Jasper and siliceous limestone flakes, backed flakes and convergent flakes were the technological objectives of the debitage. A marginal volumetric debitage aimed at producing bladelets was also attested.

Middle Palaeolithic lithic tools: Techno-functional and use-wear analysis of target objects from SU 13 at the Oscurusciuto rock shelter, Southern Italy

The Oscurusciuto rock shelter (Ginosa, Puglia, southern Italy) is a Middle Palaeolithic site characterized by a significant stratigraphy made up by several anthropic levels. The stratigraphic unit 13, consisting of a sandy compact deposit mixed with pyroclastic sediment, is a short palimpsest situated on a layer of tephra, identified as Mt. Epomeo green tuff (dated Ar/Ar ~ 55 ka BP). From a technological point of view, the aims of the production were backed flakes, convergent flakes, and other flakes obtained by means of a Levallois debitage, plus (less represented) bladelets produced by an additional volumetric reduction system. Our aim in this research was to examine a selection of the above-mentioned target objects produced by debitage in order to understand the manufacture and life-cycle of each single tool from a dynamic perspective. We integrated techno-functional and use-wear analyses: the first was implemented to globally comprehend each tool, identifying each single techno-functional unity (prehensile and transformative portions), whereas the second revealed the way in which these tools had been used, proceeding to identify the activity involved (e.g., piercing, cutting and/or scraping), and the type of material (vegetable/animal, soft/hard) on which these activities had been carried out. The combined use of these two approaches allows us to ascertain the intention of the prehistoric craftsmen, the gestures and procedures involved in making the tools, and the way they had been used. From one single object we are thus able to reconstruct a series of complex behaviours, encompassing the creation, the life-cycle and finally the ‘death’ or repurposing of the tool in question

Hydrogen peroxide detection with quartz-enhanced photoacoustic spectroscopy using a distributed-feedback quantum cascade laser

A quartz-enhanced photoacoustic spectroscopy sensor system was developed for the sensitive detection of hydrogen peroxide (H2O2) using its absorption transitions in the v6 fundamental band at ∼7.73 μm. The recent availability of distributed-feedback quantum cascade lasers provides convenient access to a strong H2O2 absorption line located at 1295.55 cm−1. Sensor calibration was performed by means of a water bubbler that generated titrated average H2O2vapor concentrations. A minimum detection limit of 12 parts per billion (ppb) corresponding to a normalized noise equivalent absorption coefficient of 4.6 × 10−9 cm−1W/Hz1/2 was achieved with an averaging time of 100 s

Fontana Ranuccio (excavations 2019-2022) and Colle Marino (excavations 2020-2021): Middle Pleistocene chronostratigraphic evidence of the earliest inhabitants in the Anagni basin

Recent fieldwork of the Istituto Italiano di Paleontologia Umana in the Anagni basin (Latin Valley, southern Latium, central Italy) has provided new insights into the dynamics of human settlement and adaptation in this area during the Middle Pleistocene. This paper summarizes the still partially unpublished data on the chronostratigraphy of two important prehistoric sites: Fontana Ranuccio, dating from about 400,000 years ago, and Colle Marino, whose lithic industry has so far been attributed to an early stage of the Middle Pleistocene. At Fontana Ranuccio, stratigraphic studies highlighted the depositional dynamics and the processes involved in the formation of the archeological unit, consisting of partly reworked volcanic material, which can be now divided into distinct sub-units. At Colle Marino, a 35-meter-deep core drilling and an excavation campaign allowed us to verify the nature and provenance of lithic artifacts found on the surface in past decades. Radiometric analyses dated these artifacts from about 700,000 years ago