Stability conditions on Kuznetsov components

We introduce a general method to induce Bridgeland stability conditions on semiorthogonal decompositions. In particular, we prove the existence of Bridgeland stability conditions on the Kuznetsov component of the derived category of many Fano threefolds (including all but one deformation type of Picard rank one), and of cubic fourfolds. As an application, in the appendix, written jointly with Xiaolei Zhao, we give a variant of the proof of the Torelli theorem for cubic fourfolds by Huybrechts and Rennemo.Comment: 52 pages. Appendix about the Torelli theorem for cubic fourfolds by A. Bayer, M. Lahoz, E. Macri', P. Stellari, and X. Zhao. v2: main results also for characteristic p; updated discussion about related wor

Volontari statunitensi sul fronte occidentale dal 1914 al 1917 tra partecipazione ai combattimenti e interventismo umanitario

The paper provides an analysis of the foreign volunteers’ intervention in France during the First World War. It discusses the activities of the US humanitarian relief, that from the Franco-Prussian War evolved into permanent structures such as the American Relief Clering House (ARCH) and the American Ambulance Field Service (AAFS) and also analyzes the phenomenon of American volunteers in the French army and in the organization of the Lafayette Escadrille. Particular note is given to the phenomenon of American ambulance volunteers in the Harjes Formation and Norton's Motor Ambulance Corps. It is also described the evolution of the humanitarian activities of the volunteers and the contribution of Anglo-American diplomats organization of relief efforts both in France and in Belgium. In particular, the paper describes the birth and development of the two major associations of US humanitarian relief, the American Field Service (AFS) in France and the Commission for Relief in Belgium (CRB) and the contribution to the latter organization by Herbert Hoover

Henry Kissinger tra idealismo, realismo e costruttivismo. Considerazioni per il nuovo secolo

This essay deals with Henry Kissingers’ political thought, examining his main works and the analyses of his main critics. In particular, in «H-Diplo Review» some critics discuss the evolution of Kissinger’s thought during his long career of scholar and stateman

Arithmetically Cohen-Macaulay bundles on cubic threefolds

We study arithmetically Cohen-Macaulay bundles on cubic threefolds by using derived category techniques. We prove that the moduli space of stable Ulrich bundles of any rank is always non-empty by showing that it is birational to a moduli space of semistable torsion sheaves on the projective plane endowed with the action of a Clifford algebra. We describe this birational isomorphism via wall-crossing in the space of Bridgeland stability conditions, in the example of instanton sheaves of minimal charge

Characterization of age-related modifications of upper limb motor control strategies in a new dynamic environment

<p>Abstract</p> <p>Background</p> <p>In the past, several research groups have shown that when a velocity dependent force field is applied during upper limb movements subjects are able to deal with this external perturbation after some training. This adaptation is achieved by creating a new internal model which is included in the normal unperturbed motor commands to achieve good performance. The efficiency of this motor control mechanism can be compromised by pathological disorders or by muscular-skeletal modifications such as the ones due to the natural aging process. In this respect, the present study aimed at identifying the age-related modifications of upper limb motor control strategies during adaptation and de-adaptation processes in velocity dependent force fields.</p> <p>Methods</p> <p>Eight young and eight elderly healthy subjects were included in the experiment. Subjects were instructed to perform pointing movements in the horizontal plane both in a null field and in a velocity dependent force field. The evolution of smoothness and hand path were used to characterize the performance of the subjects. Furthermore, the ability of modulating the interactive torque has been used as a paradigm to explain the observed discoordinated patterns during the adaptation process.</p> <p>Results</p> <p>The evolution of the kinematics during the experiments highlights important behavioural differences between the two groups during the adaptation and de-adaptation processes. In young subjects the improvement of movement smoothness was in accordance with the expected learning trend related to the consolidation of the internal model. On the contrary, elders did not show a coherent learning process. The kinetic analysis pointed out the presence of different strategies for the compensation of the external perturbation: older people required an increased involvement of the shoulder with a different modulation of joint torque components during the evolution of the experiments.</p> <p>Conclusion</p> <p>The results obtained with the present study seem to confirm the presence of different adaptation mechanisms in young and senior subjects. The strategy adopted by young subjects was to first minimize hand path errors with a secondary process that is consistent with the optimization of the effort. Elderly subjects instead, seemed to shift the importance of the two processes involved in the control loop slowing the mechanism optimizing kinematic performance and enabling more the dynamic adaptation mechanism.</p

Characterization of age-related modifications of upper limb motor control strategies in a new dynamic environment

<p>Abstract</p> <p>Background</p> <p>In the past, several research groups have shown that when a velocity dependent force field is applied during upper limb movements subjects are able to deal with this external perturbation after some training. This adaptation is achieved by creating a new internal model which is included in the normal unperturbed motor commands to achieve good performance. The efficiency of this motor control mechanism can be compromised by pathological disorders or by muscular-skeletal modifications such as the ones due to the natural aging process. In this respect, the present study aimed at identifying the age-related modifications of upper limb motor control strategies during adaptation and de-adaptation processes in velocity dependent force fields.</p> <p>Methods</p> <p>Eight young and eight elderly healthy subjects were included in the experiment. Subjects were instructed to perform pointing movements in the horizontal plane both in a null field and in a velocity dependent force field. The evolution of smoothness and hand path were used to characterize the performance of the subjects. Furthermore, the ability of modulating the interactive torque has been used as a paradigm to explain the observed discoordinated patterns during the adaptation process.</p> <p>Results</p> <p>The evolution of the kinematics during the experiments highlights important behavioural differences between the two groups during the adaptation and de-adaptation processes. In young subjects the improvement of movement smoothness was in accordance with the expected learning trend related to the consolidation of the internal model. On the contrary, elders did not show a coherent learning process. The kinetic analysis pointed out the presence of different strategies for the compensation of the external perturbation: older people required an increased involvement of the shoulder with a different modulation of joint torque components during the evolution of the experiments.</p> <p>Conclusion</p> <p>The results obtained with the present study seem to confirm the presence of different adaptation mechanisms in young and senior subjects. The strategy adopted by young subjects was to first minimize hand path errors with a secondary process that is consistent with the optimization of the effort. Elderly subjects instead, seemed to shift the importance of the two processes involved in the control loop slowing the mechanism optimizing kinematic performance and enabling more the dynamic adaptation mechanism.</p