A dual output polarimeter devoted to the study of the Cosmic Microwave Background

We have developed a correlation radiometer at 33 GHz devoted to the search for residual polarization of the Cosmic Microwave Background (CMB). The two instruments`s outputs are linear combination of two Stokes Parameters (Q and U or U and V). The instrument is therefore directly sensitive to the polarized component of the radiation (respectively linear and circular). The radiometer has a beam-width oif 7 or 14 deg, but it can be coupled to a telescope increasing the resolution. The expected CMB polarization is at most a part per milion. The polarimeter has been designed to be sensitive to this faint signal, and it has been optimized to improve its long term stability, observing from the ground. In this contribution the performances of the instrument are presented, together with the preliminary test and observations.Comment: 12 pages, 6 figures, in print on the Proc. SPIE Conf. - August 200

Criminogenic and harm-enabling features of social media platforms: the case of sharenting practices

Sharenting – that is, the sharing of identifying and sensitive information of minors, who are often overexposed online by parents or guardians – has, at times, criminogenic potential, as the information shared can enable both heinous crimes and other types of harmful conducts. While most research on sharenting has focused on the sharenters and their agency, there is a gap in addressing whether and to what extent social media platforms display criminogenic or other harm-enabling features that can render sharenting risky for affected minors. By relying on a adapted crime proofing of legislation approach, our contribution analyses the self-regulations (in the form of corporate documents and forms of self-organisation) of five major social media platforms, and identifies several risks and vulnerabilities to harmful sharenting practices embedded in the platforms’ policies. In doing so, the study demonstrates how criminological imagination can effectively contribute to the multidisciplinary debates on digital ecosystems and their regulation, paving the way for a reduction of criminogenic and harming opportunities online

Patterns of innovation during the Industrial Revolution: A reappraisal using a composite indicator of patent quality

The distinction between macro- and microinventions is at the core of recent debates on the Industrial Revolution. Yet, the empirical testing of this notion has remained elusive. We address this issue by introducing a new quality indicator for all patents granted in England in the period 1700–1850. The indicator provides the opportunity for a large-scale empirical appraisal of macro- and microinventions. Our findings indicate that macroinventions did not exhibit any specific time-clustering, while microinventions were characterized by clustering behavior. In addition, we also find that macroinventions displayed a labor-saving bias and were mostly introduced by professional engineers. These results suggest that Allen's and Mokyr's views of macroinventions, rather than conflicting, should be regarded as complementary

Geomorphology and hydrochemistry of 12 Alpine lakes in the Gran Paradiso National Park, Italy

Twelve Alpine lakes located in the Gran Paradiso National Park, in the western Italian Alps, were sampled during the ice free period in 2008 and analysed for the main morphological, chemical and physical variables in relation to the characteristics of their watershed, with the aim to create a reference database for present and future ecological studies and to support conservation politics with scientific data. The results highlighted that weathering process and direct precipitation input are the main factors determining the hydrochemistry of the studied lakes; moreover the morphological characteristics highly affects the physical properties of the lakes starting from stratification process. The acidification status, the atmospheric input of N compounds and the supply of nutrients were considered in detail. The studied lakes seem to be well preserved by acidification risk. Comparing data from Gran Paradiso National Park with data from European mountain regions ranging in N deposition rates, allows to consider long range anthropogenic impact: the detection of relative low Total Nitrogen (TN) concentration is not necessarily a synonym of a soft impact of long range pollutants, being the final nitrogen concentration dependent from retention process, closely related to catchment characteristics, besides N deposition rates; moreover the dominance of Inorganic Nitrogen (IN) on Organic Nitrogen (ON) highlights that the lakes are interested by N deposition and probably by long range transport of pollutants produced in the urbanized area surrounding the massif. However the Gran Paradiso National Park area is by far less affected by atmospheric pollutants than other Alpine regions, as the Central Alps. Total Phosphorus (TP) concentration in Gran Paradiso lakes (1-13 ?g L-1, mean level = 4 ?g L-1) is an index of oligotrophic and ultraoligotrophic conditions and according to Redfield's ratio phosphorus is mainly the phytoplankton growth limiting element, assuming a key role in biological processes and food-web dynamics; the high TN:TP ratio values detected in the studied lakes reflects the low N retention capacity of alpine sparse vegetation by comparison with prairies or forests

TRIS II: search for CMB spectral distortions at 0.60, 0.82 and 2.5 GHz

With the TRIS experiment we have performed absolute measurements of the sky brightness in a sky circle at $\delta = +42^{\circ}$ at the frequencies $\nu =$ 0.60, 0.82 and 2.5 GHz. In this paper we discuss the techniques used to separate the different contributions to the sky emission and give an evaluation of the absolute temperature of the Cosmic Microwave Background. For the black-body temperature of the CMB we get: $T_{cmb}^{th}=(2.837 \pm 0.129 \pm 0.066)K$ at $\nu=0.60$ GHz; $T_{cmb}^{th}=(2.803 \pm 0.051 ^{+0.430} _{-0.300})K$ at $\nu=0.82$ GHz; $T_{cmb}^{th}=(2.516 \pm 0.139 \pm 0.284)K$ at $\nu=2.5$ GHz. The first error bar is statistic (1$\sigma$) while the second one is systematic. These results represent a significant improvement with respect to the previous measurements. We have also set new limits to the free-free distortions, $-6.3 \times 10^{-6} < Y_{ff} < 12.6 \times 10^{-6}$, and slightly improved the Bose-Einstein upper limit, $|\mu| < 6 \times 10^{-5}$, both at 95% confidence level.Comment: accepted for publication in The Astrophysical Journa

TRIS I: Absolute Measurements of the Sky Brightness Temperature at 0.6, 0.82 and 2.5 GHz

At frequencies close to 1 GHz the sky diffuse radiation is a superposition of radiation of Galactic origin, the 3 K Relic or Cosmic Microwave Background Radiation, and the signal produced by unresolved extragalactic sources. Because of their different origin and space distribution the relative importance of the three components varies with frequency and depends on the direction of observation. With the aim of disentangling the components we built TRIS, a system of three radiometers, and studied the temperature of the sky at $\nu =0.6$, $\nu = 0.82$ and $\nu = 2.5$ GHz using geometrically scaled antennas with identical beams (HPBW = $18^{\circ} \times 23^{\circ}$). Observations included drift scans along a circle at constant declination $\delta=+42^{\circ}$ which provided the dependence of the sky signal on the Right Ascension, and absolute measurement of the sky temperature at selected points along the same scan circle. TRIS was installed at Campo Imperatore (lat. = $42^{\circ}~26'$ N, long.= $13^{\circ}~33'$, elevation = 2000 m a.s.l.) in Central Italy, close to the Gran Sasso Laboratory.Comment: Accepted for publication in The Astrophysical Journa

Blue toe syndrome: A challenging diagnosis

\u201cBlue toe syndrome\u201d (BTS) refers to the acute onset of purple painful digits in the absence of evident trauma, cold-associated injury or disorders that induce generalized cyanosis. The term was used for the first time in 1976 by Komody, who underlined the vascular etiology of the disease and its possible diagnostic confirmation through angiography.[1,2] Indeed, BTS may occur from end-arterial occlusion, impaired venous outflow, and/or abnormal blood circulation. Peripheral microembolism with distal arterial occlusion is one of the most frequent underlying mechanisms of the disease and consists of disrupted material from ulcerated atheromatous plaques (atheromatous or cholesterol crystal emboli). The case described by us assumes significance because of an atypical clinical presentation of a peripheral embolism from an abdominal aortic aneurysm, hence necessitating a high index of suspicion to achieve the correct diagnosis.

Search for distortions in the spectrum of the Cosmic Microwave Radiation

We present preliminary results of TRIS, an experiment dedicated to the search of deviations from a pure planckian distribution in the spectrum of the Cosmic Microwave Background at frequencies close to 1 GHzComment: 9 pages, in press on the Proc. of the 3rd Sakharov Conf. - Moscow 200