Local versus global factor models: time-series versus cross-sectional evidence

Many studies agree on the fact that during the late 1980s and 1990s financial market integration increased substantially. Under an efficient and integrated financial market, a set of global risk factors should price international stock returns. However, despite the perception that currently financial markets are highly integrated, many researches proved that empirical local factor models outperform global factor models. We investigate the performance of global factors respect with local factors through a time series and a cross sectional analysis

Prefetti e praesides nell'amministrazione giudiziaria dell'Egitto tardoantico: ambiti di competenza e prosopografia (284-397)

Si è mirato a fornire con il presente elaborato una nuova analisi della documentazione papiracea disponibile sui governatori dell'Egitto tardoantico, mettendo poi a confronto i dati ottenuti con le informazioni provenienti da altre fonti. In una prima parte sono passati in rassegna i dati utili per un'indagine storica (dinamiche di selezione dei governatori e relazione con la politica imperiale, carriere, dati sulle loro competenze) e i criteri utilizzati per l'analisi dei documenti su papiro (rassegna delle espressioni formulari riscontrate). Dopo le appendici, seguono infine schede prosopografiche dove le fonti sono state discusse nel dettaglio, una lista in ordine cronologico dei governatori in carica in Egitto, una sinossi delle fonti papirologiche

I governatori dell'Egitto nella documentazione del IV sec. d.C.: una rassegna e un'analisi dei termini e delle espressioni ricorrenti

It is possible to detect some linguistic innovations and peculiar expressions in the documents of the 4th c. A.D., which regard prefects and other governors of the Egyptian provinces. This paper aims to show this vocabulary and its changing and developing through the century, mostly in edicts, letters, petitions and acts of proceedings. This analysis will allow us to find some possible criteria for dating and interpreting this type of document

Metodi di Monte Carlo applicati a sistemi di comunicazione digitali

L’interpretazione dei fenomeni aleatori con metodi statistici conobbe una rinascita a partire dal 1945-1946 con l’avvento del campionamento statistico, ribattezzato Metodo di Monte Carlo; quest’ultimo si basa sull’espressione di un problema matematico di interesse come valore atteso di una qualche variabile aleatoria e sull’utilizzo della legge dei grandi numeri per determinare un buon stimatore dell’evento di interesse. L’elaborato sviluppa inizialmente una breve descrizione del metodo, soffermandosi, in particolare, sull’integrazione Monte Carlo e la stima di Monte Carlo per la valutazione della probabilità di un evento; quindi affronta una breve digressione sui metodi asintotici e gli MCMC (metodi Markov chain Monte Carlo). Infine, illustra tre particolari applicazioni dei metodi di Monte Carlo in sistemi di comunicazione digitali: la simulazione del comportamento di un canale di comunicazione digitale AWGN in modulazioni BPSK e BFSK, e una simulazione Monte Carlo per il calcolo della coda di una N(0,1)ope

La logistica in outsorcing: il caso number 1 logistics

L'evoluzione del concetto di logistica ha modificato i presupposti alla base dell'esternalizzazione di tale attività da parte delle aziende. Se prima il motivo principale era il mantenimento dei costi che essa comportava, ora l'outsourcing della logistica assume un carattere strategico, un'operazione potenzialmente in grado di creare un vantaggio rispetto ai concorrenti.ope

A no-pure-boost uncertainty principle from spacetime noncommutativity

We study boost and space-rotation transformations in kappa-Minkowski noncommutative spacetime, using the techniques that some of us had previously developed (hep-th/0607221) for a description of translations in kappa-Minkowski, which in particular led to the introduction of translation transformation parameters that do not commute with the spacetime coordinates. We find a similar description of boosts and space rotations, which allows us to identify some associated conserved charges, but the form of the commutators between transformation parameters and spacetime coordinates is incompatible with the possibility of a pure boost.Comment: 8 pages, LaTe

Through-and-through nasal reconstruction with the bi-pedicled forehead flap

BackgroundNasal reconstruction is one of the most difficult challenges for the head and neck surgeon, especially in the case of complex full thickness defects following malignant skin tumor resection. Full-thickness defects require demanding multi-step reconstruction.MethodsSeven patients underwent surgical reconstruction of full-thickness nasal defects with a bi-pedicled forehead flap shaped appropriately to the defect. Patients were aged between 58 and 86 years, with a mean age of 63.4 years. All of the tumors were excised using traditional surgery, and in 4 of the patients, reconstruction was performed simultaneously following negativity of fresh frozen sections of the margins under general anesthesia.ResultsNasal reconstruction was well accepted by all of the patients suffering non-melanoma skin tumors with acceptable cosmetic outcomes. The heart-shaped forehead flap was harvested in cases of subtotal involvement of the nasal pyramid, while smaller defects were reconstructed with a wing-shaped flap. No cartilaginous or osseous support was necessary.ConclusionsThis bi-pedicled forehead flap was a valid, versatile, and easy-to-implement alternative to microsurgery or multi-step reconstruction. The flap is the best indication for full-thickness nasal defects but can also be indicated for other complex facial defects in the orbital (exenteratio orbitae), zygomatic, and cheek area, for which the availability of a flap equipped with two thick and hairless lobes can be a valuable resource

A Psychometric Study of the Perinatal Assessment of Maternal Affectivity (PAMA) for the Screening of Perinatal Affective Disorders in Mothers

Recently, empirical evidence from perinatal studies has led researchers to pay more attention to fathers. The need to evaluate male suffering led at first to using the same screening tools developed for mothers. However, these instruments present validity concerns with fathers, and today the need to assume a gender-based perspective is clear. The Perinatal Assessment of Paternal Affectivity (PAPA) is a self-reported questionnaire for the screening of a variety of psychological and behavioral dimensions related to affectivity as experienced by fathers during the perinatal period. In the present study, the psychometric properties of the maternal version of the scale (Perinatal Assessment of Maternal Affectivity; PAMA) were examined. The study, based on 225 mothers and their partners (n = 215), used a cross-sectional design with a single assessment at the third trimester of pregnancy. Results indicated a one-factor structure for a seven-item version of the PAMA, which showed adequate internal consistency reliability and was associated in the expected direction with other clinically relevant variables (depression, psychological distress, perceived stress and dyadic adjustment). The findings suggest the usefulness of developing gender sensitive screening tools for the detection of perinatal affective disorders

Octave bias in an absolute pitch identification task

Octave errors are common within musicians, even among absolute pitch possessors. Overall, evidence shows pitch class and octave to be perceived in a different way, even if they are highly connected. We investigated whether pitch class perception, in an absolute pitch identification task, can be influenced by the octave context, examined among two consecutive octaves. Participants, all musicians with formal musical education, showed different response patterns in the two octaves even if the octave context was explicitly told to be task irrelevant. The direction of errors revealed a consistent tendency to underestimate pitch height in the lowest octave and to overestimate pitch height in the highest octave. Thus, pitch class identification showed to be biased by the octave context. These results are discussed in terms of polarity and pitch enhancement