Severi Varieties and Brill-Noether theory of curves on abelian surfaces

Severi varieties and Brill-Noether theory of curves on K3 surfaces are well understood. Yet, quite little is known for curves on abelian surfaces. Given a general abelian surface $S$ with polarization $L$ of type $(1,n)$, we prove nonemptiness and regularity of the Severi variety parametrizing $\delta$-nodal curves in the linear system $|L|$ for $0\leq \delta\leq n-1=p-2$ (here $p$ is the arithmetic genus of any curve in $|L|$). We also show that a general genus $g$ curve having as nodal model a hyperplane section of some $(1,n)$-polarized abelian surface admits only finitely many such models up to translation; moreover, any such model lies on finitely many $(1,n)$-polarized abelian surfaces. Under certain assumptions, a conjecture of Dedieu and Sernesi is proved concerning the possibility of deforming a genus $g$ curve in $S$ equigenerically to a nodal curve. The rest of the paper deals with the Brill-Noether theory of curves in $|L|$. It turns out that a general curve in $|L|$ is Brill-Noether general. However, as soon as the Brill-Noether number is negative and some other inequalities are satisfied, the locus $|L|^r_d$ of smooth curves in $|L|$ possessing a $g^r_d$ is nonempty and has a component of the expected dimension. As an application, we obtain the existence of a component of the Brill-Noether locus $\mathcal{M}^r_{p,d}$ having the expected codimension in the moduli space of curves $\mathcal{M}_p$. For $r=1$, the results are generalized to nodal curves.Comment: 29 pages, 3 figures. Comments are welcome. 2nd version: added some references in Rem. 7.1

Activity Recognition Chain: sviluppo di uno strumento finalizzato allo studio del sincronismo nei movimenti umani

Il presente lavoro effettua una ricerca sulle possibilità, problemi e soluzioni offerte nel campo del monitoraggio di attività umane attraverso l'analisi di segnali provenienti da uno o più sensori. Dopo uno studio dettagliato sulle modalità di raccolta dei dati e sui vari scenari applicativi, si è pensato di implementare un completo sistema di interazione con i sensori considerati. In particolare è stata posta l'attenzione sulle potenzialità offerte dalle informazioni provenienti da accelerometri. In una prima fase del lavoro si sono studiate le modalità di raccolta e comunicazione dei dati ed è stato creato un ambiente di lavoro per la visualizzazione e memorizzazione delle informazioni che potesse essere espandibile e trasportabile su numerose piattaforme e sistemi operativi. In una seconda fase, è stata gestita l'informazione sensoriale, estraendone le caratteristiche e analizzando il segnale. Particolari algoritmi basati principalmente su strumenti matematici di analisi statistica (correlazione) sono stati utilizzati per monitorare l'andamento qualitativo di uno o più movimenti. L'obiettivo è stato quello di rilevare sincronia o meno tra movimenti offrendo un feedback visivo e uditivo real-time che aiutasse a guidare l'utente verso un miglioramento delle performance in un certo ambito applicativo. Sulla base di queste osservazioni, è stato implementato un prototipo che analizza la sincronia tra movimenti in diverse modalità al fine di migliorare le performance sportive di un atleta. Più in particolare si è cercato uno strumento da affiancare all'allenatore per monitorare le prestazioni di una squadra nel nostro caso di canottaggio. Con l'utilizzo di soli accelerometri sono stati raggiunti risultati soddisfacenti lasciando ampi margini di miglioramento

Optimal Operations Management of Hybrid Energy Systems Through Short-Term Atmospheric and Demand Forecasts

Abstract The complexity of systems for energy production through renewable energy sources (RESs) is constantly increasing considering the integration of multiple modules, e.g. different RES sources, energy storage in batteries and connection to national grid for energy trade purpose. This significant complexity could represent a threat but also an opportunity if adequately managed. Aim of this paper is to propose two different approaches to manage the hourly electricity flows between the different components of a hybrid energy system (HES) fueled by PV modules and a wind turbine, equipped with a battery storage system (BES) to satisfy the demand of a user load with the opportunity to sell and purchase the electricity to/from the national grid. The first approach is a heuristic algorithm (HA) which defines robust but constant dispatching criteria of the energy flows between the HES components considering just the current value of energy production and demand with the aim of minimizing the electricity purchased by the grid. On the contrary, the second approach is a mixed integer linear programing (MILP) model which defines the optimal value of the energy flows to maximize the net profit of the HES operations determined by the electricity sales revenues minus the energy purchase costs. The developed MILP leverages the short-term forecast of the atmospheric conditions and user demand as well it considers variable energy sale and purchase pricing in the different daily hours. Both these approaches have been tested and validated through a case study of a residential building in which multiple households live located in the suburban area of Munich (Germany). The obtained results highlight how the MILP outperforms HA considering the net profit achievable weekly due to electricity trade with the grid. In particular, the MILP improve the HA economic performance of the HES operation management of 18% on average over the different months of the year

Epidemiology of West Nile in Europe and in the Mediterranean Basin

In the last 30 years several cases of West Nile (WN) virus infection were reported in horses and humans in Europe and in the Mediterranean Basin. Most of them were determined by strains of the Lineage 1 included in the European Mediterranean/Kenyan cluster. Strains of this cluster are characterised by a moderate pathogenicity for horses and humans and limited or no pathogenicity for birds. In recent years, however, WN cases determined by strains grouped in the Israeli/American cluster of Lineage 1 or in the lineage 2 have been reported in Hungary and Austria. The role of migrating birds in introducing new viruses to Europe has been often demonstrated. The migratory birds, which may be infected in their African wintering places, carry the virus northward to European sites during spring migrations. In the past, the virus introduction determined occasional cases of WN. In the recent years, new epidemiological scenarios are developing. In few occasions it has been evidenced the capability of WNV strains of overwintering by using local birds and mosquitoes. Species of Culex amongst mosquitoes and magpies (Pica pica), carrion crows (Corvus corone) and rock pigeons (Columba livia) amongst resident birds are the most probable species involved in this hypothetical WND endemic cycle

Hydroxyapatite nanocrystals as a smart, pH sensitive, delivery system for kiteplatin

Hydroxyapatite (HA) nanocrystals are important inorganic constituents of biological hard tissues in vertebrates and have been proposed as a bone substitute or a coating material for prostheses in biomedicine. Hydroxyapatite is also amenable for its capacity to bind to a great variety of biomolecules and therapeutic agents. As drug carriers, apatite nanoparticles also have the advantage of pH dependent solubility and low toxicity. Thus HA nanoparticles are negligibly soluble at physiological pH but their dissolution is accelerated at lower pH such as that typically found in the vicinity of tumors. In the present study we have investigated the adsorption on and the release from biomimetic HA nanoparticles of two platinum derivatives of cis-1,4-diaminocyclohexane ([PtX2(cis-1,4-DACH)], X2 = Cl2 (1) and 1,1-cyclobutanedicarboxylate (CBDCA, 2)). The first of the two compounds proved to be active against colon cancer cells also resistant to oxaliplatin. The release has been investigated as a function of pH to mimic the different physiological environments of healthy tissues and tumors, and the in vitro cytotoxicity of the releasates from the HA matrices has been assessed against various human cancer cell lines. The results fully confirmed the potential of 1-loaded HA nanoparticles as bone-specific drug delivery devices

Understanding West Nile virus transmission: mathematical modelling to quantify the most critical parameters to predict infection dynamics

West Nile disease is a vector-borne disease caused by West Nile virus (WNV), involving mosquitoes as vectors and birds as maintenance hosts. Humans and other mammals can be infected via mosquito bites, developing symptoms ranging from mild fever to severe neurological infection. Due to the worldwide spread of WNV, human infection risk is high in several countries. Nevertheless, there are still several knowledge gaps regarding WNV dynamics. Several aspects of transmission taking place between birds and mosquitoes, such as the length of the infectious period in birds or mosquito biting rates, are still not fully understood, and precise quantitative estimates are still lacking for the European species involved. This lack of knowledge affects the precision of parameter values when modelling the infection, consequently resulting in a potential impairment of the reliability of model simulations and predictions and in a lack of the overall understanding of WNV spread. Further investigations are thus needed to better understand these aspects, but field studies, especially those involving several wild species, such as in the case of WNV, can be challenging. Thus, it becomes crucial to identify which transmission processes most influence the dynamics of WNV. In the present work, we propose a sensitivity analysis to investigate which of the selected epidemiological parameters of WNV have the largest impact on the spread of the infection. Based on a mathematical model simulating WNV spread into the Lombardy region (northern Italy), the basic reproduction number of the infection was estimated and used to quantify infection spread into mosquitoes and birds. Then, we quantified how variations in four epidemiological parameters representing the duration of the infectious period in birds, the mosquito biting rate on birds, and the competence and susceptibility to infection of different bird species might affect WNV transmission. Our study highlights that knowledge gaps in WNV epidemiology affect the precision in several parameters. Although all investigated parameters affected the spread of WNV and the modelling precision, the duration of the infectious period in birds and mosquito biting rate are the most impactful, pointing out the need of focusing future studies on a better estimate of these parameters at first. In addition, our study suggests that a WNV outbreak is very likely to occur in all areas with suitable temperatures, highlighting the wide area where WNV represents a serious risk for public healt