Stop-loss a tempo continuo e protezione dinamica di un fondo d'investimento

Nella prima parte del nostro lavoro, il surplus di una compagnia d'assicurazione è modellizzato come un processo di Wiener. Consideriamo un contratto d'assicurazione dinamica di solvibilità. Secondo questo contratto, i pagamenti necessari sono effettutati istantaneamente, in modo che il surplus modificato non divenga mai negativo. Matematicamente, questo corrisponde ad introdurre una barriera riflettente in zero. Otteniamo così un'espressione esplicita per il premio netto di un tale contratto. Nella seconda parte, consideriamo un fondo d'investimento il cui valore unitario è modellizzato da un moto browniano geometrico. Differenti forme di protezione di fondi d'investimento sono esaminate. La più semplice consiste in una garanzia che fornisce istantaneamente i pagamenti necessari, di modo che il valore unitario modificato del fondo non scenda sotto un determinato livello protetto. Esiste un'espressione esplicita per il prezzo di una tale garanzia. Questo risultato può anche essere utilizzato per valutare il prezzo di una garanzia in cui il livello protetto è una funzione esponenziale del tempo. In più, è dimostrato come sintetizzare questa garanzia, costruendo il portafoglio replicante. La garanzia dinamica di fondi d'investimento è paragonata all'opzione di vendita corrispondente, e si è osservato che per delle scadenze corte, il rapporto dei due prezzi è di circa 2. Infine ci interesseremo al prezzo di una protezione più esotica, nella quale il valore unitario garantito in ogni momento è una frazione fissa del valore unitario modificato massimo osservato fino a quel moment

Rearfoot kinematics in distance runners: association with overuse injuries

Distance runners suffer often from overuse injures, caused by excessive pronation or supinating foot. The purpose of this study was to compare the rearfoot kinematics and the questionnaire results of incidences of overuse injuries symptoms. Fourteen distance runners, who were distributed into the more-symptomatic (MSL, n = 7) and less-symptomatic (LSL, n = 7) groups according to the questionnaire participated in this study. The subjects ran at average speed 3.79 m·s–1 on the 5,8 m runway with four markers set on rearfoot and shank, and kinematics were determined using the motion analysis system with 6 and 8 cameras. For the rearfoot kinematics analysis the angles between calcaneus and shank in both legs were measured: angle at impact; maximum angle; the pronation amplitude; time from impact to maximum angle; time from maximum angle to toe-off supination. The pronation amplitude in the right foot was greater (p < 0.05) in MSL compared to LSL group (5.5º and 8.2º, respectively; p = 0.02). The other measured parameters did not differ significantly between the groups. We concluded that the variations in rearfoot kinematics cannot be the reasons for causing the symptoms of overuse and their origin should be searched from training errors

Using spectral diversity and heterogeneity measures to map habitat mosaics: An example from the Classical Karst

Questions: Can we map complex habitat mosaics from remote-­sensing data? In doing this, are measures of spectral heterogeneity useful to improve image classification performance? Which measures are the most important? How can multitemporal data be integrated in a robust framework? Location: Classical Karst (NE Italy). Methods: First, a habitat map was produced from field surveys. Then, a collection of 12 monthly Sentinel-­2 images was retrieved. Vegetation and spectral heterogeneity (SH) indices were computed and aggregated in four combinations: (1) monthly layers of vegetation and SH indices; (2) seasonal layers of vegetation and SH indices; (3) yearly layers of SH indices computed across the months; and (4) yearly layers of SH indices computed across the seasons. For each combination, a Random Forest clas- sification was performed, first with the complete set of input layers and then with a subset obtained by recursive feature elimination. Training and validation points were independently extracted from field data. Results: The maximum overall accuracy (0.72) was achieved by using seasonally ag- gregated vegetation and SH indices, after the number of vegetation types was re- duced by aggregation from 26 to 11. The use of SH measures significantly increased the overall accuracy of the classification. The spectral β-­diversity was the most im- portant variable in most cases, while the spectral α-­diversity and Rao's Q had a low relative importance, possibly because some habitat patches were small compared to the window used to compute the indices. Conclusions: The results are promising and suggest that image classification frame- works could benefit from the inclusion of SH measures, rarely included before. Habitat mapping in complex landscapes can thus be improved in a cost-­and time-­effective way, suitable for monitoring applications

Using spectral diversity and heterogeneity measures to map habitat mosaics: An example from the Classical Karst

Questions Can we map complex habitat mosaics from remote-sensing data? In doing this, are measures of spectral heterogeneity useful to improve image classification performance? Which measures are the most important? How can multitemporal data be integrated in a robust framework? Location Classical Karst (NE Italy). Methods First, a habitat map was produced from field surveys. Then, a collection of 12 monthly Sentinel-2 images was retrieved. Vegetation and spectral heterogeneity (SH) indices were computed and aggregated in four combinations: (1) monthly layers of vegetation and SH indices; (2) seasonal layers of vegetation and SH indices; (3) yearly layers of SH indices computed across the months; and (4) yearly layers of SH indices computed across the seasons. For each combination, a Random Forest classification was performed, first with the complete set of input layers and then with a subset obtained by recursive feature elimination. Training and validation points were independently extracted from field data. Results The maximum overall accuracy (0.72) was achieved by using seasonally aggregated vegetation and SH indices, after the number of vegetation types was reduced by aggregation from 26 to 11. The use of SH measures significantly increased the overall accuracy of the classification. The spectral β-diversity was the most important variable in most cases, while the spectral α-diversity and Rao's Q had a low relative importance, possibly because some habitat patches were small compared to the window used to compute the indices. Conclusions The results are promising and suggest that image classification frameworks could benefit from the inclusion of SH measures, rarely included before. Habitat mapping in complex landscapes can thus be improved in a cost- and time-effective way, suitable for monitoring applications

Spatial patterns of coastal dune plant diversity reveal conservation priority hotspots in and out a network of protected areas

Effective conservation planning requires identifying priority hotspots to allocate resources. To preserve biodiversity, it is crucial to consider α, β and γ-diversity and protect the irreplaceable sites with high ecological uniqueness, which can host uncommon species assemblages that would be lost if only species-rich sites were protected. Coastal dunes, hosting highly specialized plant communities, are among the most threatened ecosystems worldwide. In this study, we identified conservation priority hotspots to assess the effectiveness of the network of protected areas in coastal dunes of Tuscany (central Italy), using data on plant communities collected in 506 plots. We additively partitioned γ-diversity in its α and β components, observing a significant variation at all spatial levels only for dune species. In terms of α-diversity, we found that Northern protected sites were richer in dune species, while synanthropic and alien species were equally present inside and outside protected areas of the region. By partitioning the total β-diversity into its components (replacement and richness difference), we found a prevalence of replacement for dune species, indicating the most unique sites as the ones to favor for conservation. Unique sites were identified through Local Contributions to Beta Diversity and their conservation value was determined by their species composition and the relationship with landscape variables. Unique sites with high conservation value were only partly protected, while some protected sites were altered and required restoration. Our approach proved effective for identifying the most unique sites, indicating some issues in the existing protected network, while providing valuable information on sites to prioritize for future conservation actions

The reproduction in women affected by cooley disease

The health background management and outcomes of 5 pregnancies in 4 women affected by Cooley Disease, from Paediatric Institute of Catania University, are described, considering the preconceptual guidances and cares for such patients. These patients were selected among a group of 100 thalassemic women divided into three subgroups, according to their first and successive menstruation characteristics: i) patients with primitive amenorrhoea, ii) patients with secondary amenorrhoea and iii) patients with normal menstruation. Only one woman, affected by primitive amenorrhoea, needed the induction of ovulation. A precise and detailed pre-pregnancy assessment was effected before each conception. This was constituted by a series of essays, including checks for diabetes and hypothyroidism, for B and C hepatitis and for blood group antibodies. Moreover were evaluated: cardiac function, rubella immunity and transaminases. Other pregnancy monitoring, and cares during labour and delivery were effected according to usual obstetrics practice

Targeting of NAADP-dependent calcium signalling impairs growth and invasiveness of murine melanoma and tumor angiogenesis

We have recently identified a novel transduction pathway through which Vascular Endothelial Growth Factor (VEGF) controls experimentally induced neoangiogenesis, specifically involving endothelial VEGF receptor subtype 2 and the release of intracellular calcium from NAADP (Nicotinic Acid Adenosine Dinucleotide Phosphate) responsive acidic stores (1). We have now extended this research to an in vivo model of tumor angiogenesis and show that the pharmacologic NAADP inhibitor Ned-19 (2) impairs the vascularization, growth and metastatic spreading of the very aggressive VEGF producing murine tumor, B16 melanoma. In parallel in vitro experiments, we tested whether Ned-19 could directly affect the production of VEGF by the tumor cells, and found that treatment of B16 cells with Ned-19 unexpectedly results in increased VEGF release. These observations indicate that in our model 1) tumor angiogenesis is impaired by Ned-19 even in the presence of increased exposure to VEGF and 2) that NAADP system is active also in B16 melanoma cells. On the basis of this second observation further possible direct effects of Ned-19 on melanoma cell aggressiveness such as growth and invasivity are presently investigated and preliminary results suggest that NAADP system inhibition could potentially represent a twofold therapeutic strategy, directly targeting both tumor angiogenesis and tumor cell growth

Delayed Capital Injections for a Risk Process with Markovian Arrivals

In this paper we propose a generalisation to the Markov Arrival Process (MAP) risk model, by allowing for a delayed receipt of required capital injections whenever the surplus of an insurance firm is negative. Delayed capital injections often appear in practice due to the time taken for administrative and processing purposes of the funds from a third party or the shareholders of a firm. We introduce a MAP risk model that allows for capital injections to be received instantaneously, or with a random delay, depending on the amount of deficit experienced by the firm. For this model, we derive a system of Fredholm integral equations of the second kind for the Gerber-Shiu function and obtain an explicit expression (in matrix form) in terms of the Gerber-Shiu function of the MAP risk model without capital injections. In addition, we show that the expected discounted accumulated capital injections and the expected discounted overall time in red, up to the time of ruin, satisfy a similar integral equation, which can also be solved explicitly. Finally, to illustrate the applicability of our results, numerical examples are given

Sandy Everlasting (Helichrysum arenarium (L.) Moench): Botanical, Chemical and Biological Properties

Sandy everlasting [Helichrysum arenarium (L.) Moench] is herbaceous perennial plant belonging to Asteraceae family and it is native to Europe, Central Asia, and China. It belongs to the section HELICHRYSUM (Asteraceae family, genus Helichrysum) along with H. plicatum DC. Prodr., which very similar phenolic profile and H. italicum (Roth), which is widely used for essential oil extraction. Its flowers have a long tradition in European ethnomedicine as a cholagogue, choleretic, hepatoprotective, and detoxifying herbal drug. The flowers are rich in phenolic compounds including flavonoids, chalcones, phenolic acids, coumarins, and pyrones. Apart frompolyphenols, other compounds such as sterols, lignans, and glycosides of aromatic compounds have been also isolated from H. arenarium. The majority of authors confirm that the most important group of compounds responsible for biological activities is flavonoids. Moreover, significant activities of naringenin, one of the main flavonoids of H. arenarium, were reported. On the other hand, there are no clinical data about testing the extracts or preparations based on H. arenarium. Although H. arenarium is well known in phytotherapy for its potential in the treatment of gallbladder disease and are classified as endangered species in a number of European countries, very few data about its cultivation are available in the literature