Bias Dependence of the Depletion Layer Width in Semi-Insulating GaAs by Charge Collection Scanning Microscopy

A procedure for the evaluation of the depletion region width of a Schottky barrier diode made on semi-insulating materials has been assessed and applied to gallium arsenide nuclear detectors. This procedure, which makes use of the optical beam induced current method of charge collection scanning microscopy, allows the direct measurement of the depletion layer width. By taking into account the high resistivity of the material under examination and measuring the diode reverse current, it is possible to evaluate the actual voltage applied at the depletion layer boundaries. It was found that, at low actual bias values, the voltage dependence of the depletion layer follows the usual square root power law, while at increasing voltages, it changes into a linear behavior. An explanation in terms of deep trap effect and trap field-enhanced capture cross-section is proposed even though further work must be done to explain the space charge width dependence on bias applied in terms of the deep trap influence

Is there a role for ‘modified VAD’ in the treatment of multiple myeloma?

VAD, (Vincristine, Doxorubicin and Dexamethasone) was initially proposed as a salvage therapy for myeloma patients in whom prior alkylating agent therapy failed, although in recent years VAD has been surpassed by novel combination therapies with new biological agents such as thalidomide (and its derivative, lenalidomide) and bortezomib. After the excellent results obtained by the novel agents, VAD can no longer be proposed in preparation to autologous transplantation, although there are still indications that VAD remains useful and clinically relevant in the initial treatment of symptomatic multiple myeloma

A nanoflare heating model for the quiet solar corona

The energy input into the lower solar corona by flare evaporation events has been modeled according to the available observations for quiet regions. The question is addressed whether such heating events can provide the observed average level of the coronal emission measure and thus of the observed flux of extreme ultraviolet (EUV) and X-ray emission without contradicting the observed average power spectrum of the emission measure, the typical emission measure variations observed for individual pixels and the observed flare energy distribution. As the assumed flare height influences the derived flare energy, the mathematical foundations of nanoflare distributions and their conversion to different height assumptions are studied first. This also allows a comparison with various published energy distributions differing in height assumptions and to relate the observations to the input parameters of the heating model. An analytic evaluation of the power spectrum yields the relationship between the average time profile of nanoflares (or microflares), assumed to be self-similar in energy, and the power spectrum. We find that the power spectrum is very sensitive to the chosen time profile of the flares. Models are found by numerical simulation that fit all available observations. They are not unique but severely constrained. We concentrate on a model with a flare height proportional to the square root of the flare area. The existence of a fitting model demonstrates that nanoflare heating of the corona is a viable and attractive mechanism.Comment: 11 pages, 7 figures, updated spelling of 1st autor's nam

Primary follicular and marginal-zone lymphoma of the breast: clinical features, prognostic factors and outcome: a study by the International Extranodal Lymphoma Study Group

Background: Primary breast lymphoma (PBL) of low-grade histology is a rare disease. This multicentric retrospective study was carried out to determine clinical features, prognosis and relapse. Patients and methods: Patients with histologically proven, previously untreated follicular or marginal-zone PBL (MZL PBL) diagnosed from 1980 to 2003 were included in the study. Major end points were progression-free survival (PFS), overall survival (OS) and potential prognostic factors. Results: We collected data on 60 cases of PBL [36 follicular and 24 marginal-zone lymphoma (MZL)]. Stage was IE or IIE in 57 patients and IVE in three patients due to bilateral breast involvement. Surgery, chemotherapy and radiotherapy (RT), alone or in combination, were used as first-line treatments in 67%, 42% and 52% of patients, respectively. Overall response rate was 98%, with a 93% complete response rate. Five-year PFS were 56% for MZL and 49% for follicular PBL (P = 0.62). Relapses were mostly in distant sites (18 of 23 cases); no patients relapsed within RT fields. Conclusions: Our data showed an indolent behaviour of MZL PBL, comparable to other primary extranodal MZL. Conversely, patients with follicular PBL had inferior PFS and OS when compared with limited-stage nodal follicular non-Hodgkin's lymphomas, suggesting an adverse prognostic role of primary breast localisation in this histological subgrou

Il blues dell'Avana: tra turismo, gentrification a marginalità urbane

Il capitolo analizza la trasformazione dell'Avana e del suo centro storico verso una dinamica di gentrification legata allo sviluppo del turismo. Questo processo si scontra con la presenza in questi luoghi "turistici" di una popolazione marginale in gran parte esclusa dalla creazione di opportunità socio-economiche. Il futuro dell'Avana passa, di conseguenza, su una strategia integrata che attivi risorse locali per promuovere inclusione e partecipazione dei residenti

Vivere, convivere in un quartiere a rischio

Analisi dei percorsi di vita e delle politiche sociali all'interno dei quartieri difficili nel contesto italiano e milanese

Costruire comunità multietniche: contesti, immaginari e pratiche sociali

Analisi delle pratiche situate multiculturali e delle prospettive di costruire comunità all'interno di contesti critici quali quartieri popolari e aree interne. Nella specifictà dei contesti si rilevano caratteri comuni che devono essere affrontate per contribure a spazi di dialogo e di ricomposizione dei possibili conflitti. A qeusto fine il ruolo attivo delle istituzioni appare decisivo e fondamentale al fine di garantire relazioni di prossimità significative

Quei soggetti spinti ai confini della società. Note critiche sul concetto di coesione sociale.

L'enfasi crescente sulla coeisone sociale e sulle politche di coesione rischia di aggravare la siutazione di emarginazione sociale ed economica. L'appello alla comunità, senza fare spazio ai diritti di cittadinanza, è distruttivo per la coesione a livello di rapporto tra i gruppi sociali a livello di percorsi di emancipazione dei soggetti. La coesione è un orizzonte etico e politico in cui collocare la costruzione dei diritti, se non si volgiono riproporre antiche classificazioni e nuove stigamtizzazioni

Ghetti urbani e rurali. Contributi di ricerca.

The term ghetto has increasingly taken an emotional connotation that focalizes the profile of a real exceptionality and social morbidity. Starting from a short review of the long sociological tradition, an introductory reflection is proposed aimed at analyzing the evocative nature associated to the ghetto. It reveals its rhetorical and stigmatizing potential. Furthermore, the ghetto in its urban and/or rural articulation highlights the result of policies of exclusion and stigamtization, as identified by articles inside direct to minorities (Black, Roma people, poor communities)