Demographic responses to short-term stress in a 19^th century Tuscan population: the case of household out-migration

This paper deals with the relationship between household emigration and short-term crisis in a rural community of mid-19th century Tuscany. Based on a detailed reconstruction of individual and household life-histories, the paper shows the close relationship between household emigration and different kinds of short-term stresses, either economic, epidemiologic or within the household. Despite the different response by SES - with the poorest strata of the population much exposed to price changes and mortality crisis - the death of the household head appears as one of the most powerful factor of household emigration

Regularity of mean curvature flow of graphs on Lie groups free up to step 2

We consider (smooth) solutions of the mean curvature flow of graphs over bounded domains in a Lie group free up to step two (and not necessarily nilpotent), endowed with a one parameter family of Riemannian metrics \sigma_\e collapsing to a subRiemannian metric $\sigma_0$ as \e\to 0. We establish $C^{k,\alpha}$ estimates for this flow, that are uniform as \e\to 0 and as a consequence prove long time existence for the subRiemannian mean curvature flow of the graph. Our proof extend to the setting of every step two Carnot group (not necessarily free) and can be adapted following our previous work in \cite{CCM3} to the total variation flow.Comment: arXiv admin note: text overlap with arXiv:1212.666

Seasonal variation of platelets in a cohort of Italian blood donors: a preliminary report

Massimo Gallerani1*, Roberto Reverberi2, Raffaella Salmi1, Michael H Smolensky3 and Roberto Manfredini4 Author Affiliations 1 Internal Medicine, Azienda Ospedaliera-Universitaria, Ferrara, Italy 2 Immunohematological and Transfusional Service, Azienda Ospedaliera-Universitaria, Ferrara, Italy 3 Department of Biomedical Engineering, The University of Texas at Austin, Austin, USA 4 Clinica Medica, Azienda Ospedaliera-Universitaria, Ferrara, ItalyBackground: Since available data are not univocal, the aim of this study was to explore the existence of a seasonal variation in platelet count. Methods: The study was based on the database of the Italian Association of Blood Volunteers (AVIS), section of Ferrara, Italy, 2001–2010. Hematological data (170,238 exams referring to 16,422 donors) were categorized into seasonal and monthly intervals, and conventional and chronobiological analyses were applied. Results: Platelets and plateletcrit were significantly higher in winter-autumn, with a main peak in December-February (average +3.4% and +4.6%, respectively, P <0.001 for both). Conclusions: Although seasonal variations have been reported for several acute cardiovascular diseases, it is extremely unlikely that such a slight increase in platelet count in winter alone may be considered as a risk factor.Biomedical [email protected]

Chisini's conjecture for curves with singularities of type xn=ymx^n=y^m

This paper is devoted to a very classical problem that can be summarized as follows: let S be a non singular compact complex surface, f:S --> P^2 a finite morphism having simple branching, B the branch curve: to what extent does B determine f? The problem was first studied by Chisini who proved that B determines S and f, assuming B to have only nodes and cusps as singularities, the degree d of f to be greater than 5, and a very strong hypothesis on the possible degenerations of B, and posed the question if the first or the third hypothesis could be weakened. Recently Kulikov and Nemirovski proved the result for d >= 12, and B having only nodes and cusps as singularities. In this paper we weaken the hypothesis about the singularities of B: we generalize the theorem of Kulikov and Nemirovski for B having only singularities of type {x^n=y^m}, in the additional hypothesis of smoothness for the ramification divisor. Moreover we exhibit a family of counterexamples showing that our additional hypothesis is necessary.Comment: 27 pages, LaTeX, 1 figure (file=polypicc.eps

Uniform Gaussian bounds for subelliptic heat kernels and an application to the total variation flow of graphs over Carnot groups

In this paper we study heat kernels associated to a Carnot group $G$, endowed with a family of collapsing left-invariant Riemannian metrics \sigma_\e which converge in the Gromov-Hausdorff sense to a sub-Riemannian structure on $G$ as \e\to 0. The main new contribution are Gaussian-type bounds on the heat kernel for the \sigma_\e metrics which are stable as \e\to 0 and extend the previous time-independent estimates in \cite{CiMa-F}. As an application we study well posedness of the total variation flow of graph surfaces over a bounded domain in (G,\s_\e). We establish interior and boundary gradient estimates, and develop a Schauder theory which are stable as \e\to 0. As a consequence we obtain long time existence of smooth solutions of the sub-Riemannian flow (\e=0), which in turn yield sub-Riemannian minimal surfaces as $t\to \infty$.Comment: We have corrected a few typos and added a few more details to the proof of the Gaussian estimate

Health and socio-demographic conditions as determinants of marriage and social mobility

This paper makes use of data collected from military registers and marriage certificates for the population of Alghero, in Sardinia, for the period 1866-1925, with the aim of investigating the role played by physical characteristics and health in the possibility of social mobility through marriage. Our findings demonstrate that, whereas physical defects and ill health had little impact on the chances of marrying an illiterate woman, these factors did have a negative effect on the chances of marrying a woman who was literate. In a context in which intergenerational social mobility remained limited and the family had the final say on marriage arrangements, it is likely that only healthy individuals were selected for marriages regarded as strategic for the purposes of forming and strengthening family alliances, and/or improving the social position within the community.health, marriage, Sardinia, social mobility

Demographic responses to short-term stress in a 19th century Tuscan population: The case of household out-migration

This paper deals with the relationship between household emigration and short-term crisis in a rural community of mid-19th century Tuscany. Based on a detailed reconstruction of individual and household life-histories, the paper shows the close relationship between household emigration and different kinds of short-term stresses, either economic, epidemiologic or within the household. Despite the different response by SES - with the poorest strata of the population much exposed to price changes and mortality crisis - the death of the household head appears as one of the most powerful factor of household emigration.emigration, household, Italy, sharecropping, short-term stress

Physical and mechanical characterization of the soft pyroclastic rocks forming the Orvieto cliff

The paper describes the results of laboratory and in situ investigations carried out on weak pyroclastic materials which could be encountered during engineering activities in volcanic regions. The research was focused on the historical town of Orvieto, representing a typical geotechnical situation which is widespread in Central Italy. The in situ investigations include cross-hole and SASW measurements performed in adjacent areas. The laboratory tests provided static and dynamic properties which were compared to the in situ data, in order to reconstruct the geotechnical model of a representative area of the town