“Dicam dumtaxat quod est historicon”: Varro and/on the past

Varro’s approach to his subjects is usually systematic and synchronic, but there are frequent diachronic digressions and observations on time and the past, often divided into three stages (remote past, near past, and present). I discuss Rust. 2.1, with a progressive concept of three successive stages in human history from Dicaearchus, and a fragment from Censorinus, where Varro distinguishes tria discrimina temporum. A significant affinity emerges between etymological research and the study of origins: both involve the study of antiquitas or the origo, and both use the genealogical-reconstructive method. The same image of gradus descendere indicates the sequence of logical and chronological steps in describing human history (Rust. 2.1.3–5) and etymological research (Ling. 5.7–9). Varro is fully aware of the difficulties in reconstructing the ancient past and the origins of language, because uncertainty is a characteristic of the origo of human history and of words

Growth, Congestion of Public Goods, and Second-Best Optimal Policy

This paper presents a general equilibrium endogenous growth model in which public spending is divided between public productive services and public consumption. A distinguishing feature of the model is the assumption that both components of public spending can be over used and, thus, congested by the private agents. We study the second-best dynamics of the model and prove that it is determinate. Moreover, we show that the optimal second-best policy could be not unique. Finally, the relationship between congestion and the optimal second-best policy, on the one hand, and congestion and the long run growth rate, on the other, is established.Endogenous growth, Congestion, Public spending, Second-Best

Internal Migration Across Italian regions: Macroeconomic Determinants and Accommodating Potential for a Dualistic Economy

We provide econometric evidence that relative per capita GDP and relative unemployment rates are the main determinants of migration flows across Italian regions from 1970 to 2002. The empirical analysis is based on an accurate study of the dynamic properties of the series. In fact, we deal with the issues of non-stationarity and cointegration and estimate an error correction model in which both the short- and long-run dynamics are modelled at once. The regional unemployment rate is robustly inversely related with net regional migration rate, while per capita GDP is strongly positively linked with it. As far as the accommodating potential of internal migration to regional unbalances, we have detected very little room for such a role. Indeed, the degree of labour mobility across Italian regions cannot be active as an effective equilibrating mechanism.Italy, Labour Migration, Internal Migration, Income Differences, Panel Cointegration

Mass-Market Receiver for Static Positioning: Tests and Statistical Analyses

Nowadays, there are several low cost GPS receivers able to provide both pseudorange and carrier phase measurements in the L1band, that allow to have good realtime performances in outdoor condition. The present paper describes a set of dedicated tests in order to evaluate the positioning accuracy in static conditions. The quality of the pseudorange and the carrier phase measurements let hope for interesting results. The use of such kind of receiver could be extended to a large number of professional applications, like engineering fields: survey, georeferencing, monitoring, cadastral mapping and cadastral road. In this work, the receivers performance is verified considering a single frequency solution trying to fix the phase ambiguity, when possible. Different solutions are defined: code, float and fix solutions. In order to solve the phase ambiguities different methods are considered. Each test performed is statistically analyzed, highlighting the effects of different factors on precision and accurac

Convergence in per-capita GDP across European regions using panel data models extended to spatial autocorrelation effects.

This paper studies the convergence of per capita GDP across European regions over a fairly long period. Most of the works are based on either cross-sectional or fixed-effects estimates. We propose the estimation of convergence in per capita GDP across European regions by making use of panel-data models extended to include spatial error autocorrelation and spatially lagged dependent variable (Anselin,1988;Elhorst,2002). This will allow us to extend the traditional ß convergence model to include a rigorous treatment of the spatial correlation among the intercept terms. A spatial analysis of such intercept terms will also be performed in order to shed light on the concept spatially conditional convergence.

Use of Kriging Technique to Study Roundabout Performance

Road intersections are dangerous places because of the many conflicting points between motorized and nonmotorized vehicles. In the case of defined traffic volume, several research groups have proved that roundabouts reduced the number of injuries and fatal accident cases. In recent years, many countries have adopted roundabouts as a standard design solution for both urban and rural roads. Several recent studies have investigated the performance of roundabouts, including some with models that calculated the entering flow (Q sub e) as a function of the circulating flow (Q sub c). Most existing models have been constructed with the use of linear or exponential statistical regression. The interpolative techniques in classical statistics are based on the use of canonical forms (linear or polynomial) that completely ignore the correlation law between collected data. As such, the determined interpolation stems from the assumption that the data represent a random sample. In the research reported in this paper, a geostatistical approach was considered: the relationship Q sub e versus Q sub c is supposed to be a regionalized phenomenon. According to that supposition, collected data do not represent a random sample of values but are supposed to be related to each other with a defined law. This recognition allows the realization of interpolation on the basis of the real law of the phenomenon. This paper discusses the fundamental theories, the applied operating procedures, and the first results obtained in modeling the Q sub e versus Q sub c relationship with the application of geostatistics

New systematic insights about plio-pleistocene moles from poland

The generic attribution of the Plio-Pleistocene Polish moles ?Neurotrichus polonicus and ?Neurotrichus skoczeni has been questioned several times in the past. The fossil material belonging to ?Neurotrichus polonicus and ?Neurotrichus skoczeni is re-evaluated here and a new diagnosis is provided on the basis of qualitative considerations. In addition, a Geometric Morphometric analysis of the humerus has been performed including both extant and extinct Neurotrichini and Urotrichini taxa for comparison. Our results proved the unique morphology of the Polish material suggesting a distinct taxonomic state. The morphological variations evidenced by the humeral shape analysis agree with the observed qualitative differences and support a new generic allocation. The new genus Rzebikia gen. nov. is proposed for all the material previoulsly ascribed to ?Neurotrichus polonicus and ?Neurotrichus skoczeni

MONITORING OF LANDSLIDES WITH MASS MARKET GPS: AN ALTERNATIVE LOW COST SOLUTION

The territory of Italy is seriously afflicted by hydrological risk, with 82% of its area affected by this phenomenon. In recent years, technologies and advanced research have played an important role in realizing complex automatic systems devoted to landslide monitoring and to alerting the population. Sometimes, the cost of these systems (communications network, sensors, software, technologies) prevents their use, and in particular the cost of sensors has a large impact on the final investment. For example, geodetic GNSS receivers are usually employed to conduct landslide monitoring, but they are costly. Nowadays, new technologies make it possible to use small and efficient low cost single frequency GPS receivers, which are able to achieve a centimetrical or better level of accuracy, in static positioning. The rapid development and diffusion of the GNSS network to provide a positioning service has made it possible to use single frequency receivers, thanks to the use of virtual RINEX. This product is generated by a network of permanent stations. In this research, the actual performance of a mass market GPS receiver was tested, with the purpose of verifying if these sensors can be used for landslide monitoring. A special slide was realized, in order to conduct a dedicated test of the detection of displacements. Tests were carried out considering two factors: acquisition time and distance from the Virtual Station. The accuracy and precision of movement determination were evaluated and compared, for each test, considering the different factors. The tests and results are described in this contributio