981 research outputs found
LEGAME TRA L¿IMMUNODEFICIENZA HIV-CORRELATA E L¿INSORGENZA DI TUMORI: ASPETTI DI METODOLOGIA STATISTICA
No full textThe aim of the present Ph.D. program was exploring methodological issues arising in studies of cancer incidence, relative risk, and survival in patients with HIV/AIDS (PHA). Aspects related to the first two objectives were explored in the first two years.
This thesis described a record-linkage study conducted between the national Italian AIDS Registry and 24 Italian cancer registries to estimate survival after a cancer diagnosis in PHA. More than 2600 cancer cases diagnosed between 1986 and 2005 were included. Survival in PHA was compared with that reported in patients without AIDS using, as comparison group, patients matched for site (1:1 for Kaposi Sarcoma, 1:2 for non-Hodgkin lymphoma, 1:5 for other cancers), sex, age, period of diagnosis, and area of residence. Overall survival and death hazard ratios (HR) compared survival in PWA with cancer to that in cancer patients without AIDS have been calculated.
Overall, the 3-year survival rate of PHA with cancer increased from 16% in 1986-1995 to 41% in 1996-2005 period, after the widespread use of antiretroviral therapy (cART). In this period, HR remained higher in PHA than in persons without AIDS (3.0, 95% confidence interval [CI]: 2.7–3.4), in particular for cancer with good prognosis, e.g., Hodgkin lymphomas (HR=8.6), non-melanoma skin cancer (H=5.0), and anal cancer (HR=4.0).
A sensitivity analysis was performed to evaluate the impact on survival and on HR of different study designs and comparison groups
Local firms’ strategies and cluster coopetition in Tuscany: the case of “Toscana Promozione” Agency
No full textThis study examines a new paradigm of coopetition strategy emerged in Tuscany, one of the most famous Italian area in the world for cultural and economic heritage. Nowadays, global success in business requires that firms implement both competitive and cooperative strategies (i.e. coopetition). This strategy, according to Ray Noorda (the founder of Novell – an American multinational software and services company headquartered in Provo, Utah), considers the advantages arising when both cooperation and competition coexist in the same domains.
In the last twenty years, articles related to coopetition investigated several aspect of this strategy; in contrast, industry level coopetition has been investigated less than the other features (Rusko, 2011). Giving the literature review, there is a lack in knowledge regarding the benefits of coopetition fostered by local governments with foreign governments.
This study presents a new approach of industry-level coopetition through the qualitative case study of the economic promotion agency in Tuscany, Toscana Promozione. The paper presents a new paradigm of coopetition strategy in where firms are in a coopetition relationship with foreign competitors (and governments) thanks to the support of local authorities.
The main result of the research is that the boundary between institution and entrepreneur must be clear, government and local authorities must enforce competitiveness to improve the environment in which firms cooperate with the institution and compete each other with their own strategy. However during economic downturn periods, government and local authorities should, also, consider the possibility to become promoter, and supporter, of emerging entrepreneurship
ENTREPRENEURIAL CULTURE, FAMILY BUSINESS AND NEW INTERNATIONAL MARKETS. THE IMPORTANCE OF INSTITUTIONS STRATEGY AS ATTRACTION FOR VENTURE CAPITALIST
No full textThis paper wants to investigate whether Institution strategy enforced during financial crisis have been able to attract venture capitalist. Furthermore we study the potential impact of an active venture capital market over family business firms’ growth overall in international perspective.
Due to the global economy crisis, the persisting financial difficulties of Euro area, the weak recovery in several other advanced economies (e.g. United States), the expected slowdown in economic growth in China, India, as well as the other elements composing the BRIC’s acronym due to the high volatility among financial markets, policy maker are still facing the following question: “which regions can drive growth and employment creation in the short to medium term?” (The Global Competitiveness Report: 2012/2013).
For this reason governments tried to encourage entrepreneurship in order to boost economic growth and job creation; however young entrepreneurial firms have difficulties in rising funds from equity investors and banks, due to the high level of conflicts of interest among the two categories.
Since an active venture capital market can boost economic growth and solve asymmetric information problems, we can understand immediately the potential link between those three categories
On the relaxation in BV(Ω; Rm) of quasi-convex integrals
No full textAbstractGiven a quasi-convex function f with linear growth, we find the integral representation in BV(Ω; Rm) of the functional F̄ arising from the relaxation of F(u) = ∝Ωf(▽u) dx, u ϵ C1(Ω; Rm), in the Lloc1(Ω; Rm) topology
Approximation of relaxed dirichlet problems by boundary value problems in perforated domains
No full textGiven an elliptic operator L on a bounded domain Ω ⊆ Rn, and a positive Radon measure μ on Ω, not charging polar sets, we discuss an explicit approximation procedure which leads to a sequence of domains Ωh ⊇ Ω with the following property: for every f ∈ H−1(Ω) the sequence uh of the solutions of the Dirichlet problems Luh = f in Ωh, uh = 0 on ∂Ωh, extended to 0 in Ω\Ωh, converges to the solution of the “relaxed Dirichlet problem” Lu + μu = f in Ω, u = 0 on ∂Ω.</jats:p
Limits of Dirichlet problems in perforated domains: a new formulation
No full textSia A un operatore ellittico lineare del secondo ordine con coefficienti
misurabili e limitati su un aperto limitato di
, sia
e sia un'arbitraria successione di sottoinsiemi aperti
di . Dimostriamo il seguente risultato di compattezza: esistono
una sottosuccessione, che indichiamo ancora con ed una
funzione w{*} K{*} tali che, per ogni f
, le soluzioni u delle
equazioni Au = f in , estese a zero su ,
convergano debolmente in all'unica
soluzione u del problema.
Studiamo inoltre in maniera sistematica le proprietà delle soluzioni
di tale equazione. Dimostriamo infine il seguente risultato di densità:
per ogni w{*}K{*} esiste una successione
di sottoinsiemi aperti di tali che per ogni f
le soluzioni u dell'equazione
Au=f in , estese a zero convergano
debolmente in alla soluzione di ({*}).Let A be a linear elliptic operator of the second order with bounded
measurable coefficients on a bounded open set of
, let
and let be an arbitrary sequence of open subsets of
. We prove the following compactness result: there exist
a subsequence, still denoted by and a function w{*}
K{*} such that, for every f
, the solutions u
of the equation Au = f in , extended by zero
on , converge weakly in
to the unique solution u of the problem.
We provide a self-contained study of the properties of the solutions
of ({*}). We prove also the following density result: for any w{*}K{*}
there exists a sequence of open subsets of
such that for every f the
solutions u of the
equation Au=f in , extended by zero on
converge weakly in to the solution
of ({*})
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