1,708 research outputs found

    Unbundling technology adoption and tfp at the firm level. Do intangibles matter?

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    We use a panel of European firms to investigate the relationship between intangible assets and productivity. We disentangle between tfp and technology adoption, while available studies so far have considered only a notion of productivity conflating the two effects. To this aim, we estimate production function parameters allowing, within each sector, for the existence of multiple technologies. We find that intangible assets both push the firm towards better technologies (technology adoption effects) and allow for a more efficient exploitation of a given technology (tfp effects)

    Hierarchy plus anarchy in quark masses and mixings

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    We introduce a new parameterisation of the effect of unknown corrections from new physics on quark and lepton mass matrices. This parameterisation is used in order to study how the hierarchies of quark masses and mixing angles are modified by random perturbations of the Yukawa matrices. We discuss several examples of flavour relations predicted by different textures, analysing how these relations are influenced by the random perturbations. We also comment on the unlikely possibility that unknown corrections contribute significantly to the hierarchy of masses and mixings.Comment: LaTeX, 18 pages, 16 PS figure

    Paratesticular Mesenchymal Malignancies: A Single-Center Case Series, Clinical Management, and Review of Literature

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    Background: Primary soft tissue sarcomas arising from the male urinary and genital tract are rare tumors, only accounting for 1% to 2% of all malignancies of the genitourinary tract. Clinical management of advanced disease is lacking in standardized recommendations due to the rarity of the disease. To date, complete and extensive surgery represents the only curative and standardized approach for localized disease, while the impact of retroperitoneal lymphadenectomy and adjuvant treatments on clinical outcomes are still unclear. Similarly, a standardized systemic treatment for advanced metastatic disease is still missing. Cases Presentation: Four out of 274 patients have been identified in our sarcoma population. The mean age was 54 years (range = 45-73). The histotypes showed liposarcoma in 2 cases and leiomyosarcoma in the remaining 2 cases. In all 4 cases, the disease was localized at presentation, patients underwent complete surgery, and no adjuvant treatments were done. Three cases presented a recurrence of disease at a mean follow-up of 86 months (range = 60-106 months), more than 7 years. Two cases were treated with a second surgery and chemotherapy and 1 case only with chemotherapy. Discussion and Conclusions: Sharing data about clinical management of paratesticular mesenchymal tumors is a key issue due to the rarity of this tumor\u2019s subtype. In this article, we report the clinical history of 4 patients affected by paratesticular mesenchymal tumor. In particular, main issues of interest are the decision of postoperative treatment and systemic treatment at time of disease recurrence

    On farm agronomic and first environmental evaluation of oil crops for sustainable bioenergy chains.

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    Energy crops, and in particular oil crops, could be an important occasion for developing new non food production rows for a new multi-functional agriculture in Italy. In this view, the use of local biomass is a fundamental starting point for the development of a virtuous energy chain that should pursue not only agricultural profitability, but also chain sustainability and that is less dependent on the global market, characterized by instability in terms of biomass availability and price. From this perspective, particular attention must be paid to crop choice on the basis of its rusticity and of its adaptability to local growing conditions and to low input cropping systems. In this context, alike woody and herbaceous biomasses, oil crops such as sunflower and rapeseed should be able to support local agricultural bioenergy chain in Italy. In addition, in a local bioenergy chain, the role of the farmers should not be limited just to grain production; but also grain processing should be performed at farm or consortium level in oilseed extraction plants well proportioned to the cropped surface. In this way, by means of a simple power generator, farmer could thus produce its own thermal and electric energy from the oil, maximizing his profit. This objective could also be achieved through the exploitation of the total biomass, including crop residues and defatted seed meals, that may be considered as fundamental additional economic and/or environmental benefits of the chain. This paper reports some results of three-years on-farm experiments on oil crop chain carried out in the framework of "Bioenergie" project, that was focused to enhance farmers awareness of these criteria and to the feasibility at open field scale of low-input cultivation of rapeseed, sunflower and Brassica carinata in seven Italian regions. In several on-farm experiences, these crops produced more than 800 kg ha-1 of oil with good energy properties. Defatted seed meals could be interesting as organic fertilizers and, in the case of B. carinata, as a biofumigant amendment that could offer a total or partial alternative to some chemicals in agriculture. Furthermore, biomass soil incorporation could contribute to C sequestration, catching CO2 from atmosphere and sinking a part in soil as stable humus. Finally, four different open field experiences carried out again in the second year of the project, have been analysed in order to evaluate their energy and greenhouse gasses balance after cultivation phase

    Splicing Reporter Mice Revealed the Evolutionally Conserved Switching Mechanism of Tissue-Specific Alternative Exon Selection

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    Since alternative splicing of pre-mRNAs is essential for generating tissue-specific diversity in proteome, elucidating its regulatory mechanism is indispensable to understand developmental process or tissue-specific functions. We have been focusing on tissue-specific regulation of mutually exclusive selection of alternative exons because this implies the typical molecular mechanism of alternative splicing regulation and also can be good examples to elicit general rule of “splice code”. So far, mutually exclusive splicing regulation has been explained by the outcome from the balance of multiple regulators that enhance or repress either of alternative exons discretely. However, this “balance” model is open to questions of how to ensure the selection of only one appropriate exon out of several candidates and how to switch them. To answer these questions, we generated an original bichromatic fluorescent splicing reporter system for mammals using fibroblast growth factor-receptor 2 (FGFR2) gene as model. By using this splicing reporter, we demonstrated that FGFR2 gene is regulated by the “switch-like” mechanism, in which key regulators modify the ordered splice-site recognition of two mutually exclusive exons, eventually ensure single exon selection and their distinct switching. Also this finding elucidated the evolutionally conserved “splice code,” in which combination of tissue-specific and broadly expressed RNA binding proteins regulate alternative splicing of specific gene in a tissue-specific manner. These findings provide the significant cue to understand how a number of spliced genes are regulated in various tissue-specific manners by a limited number of regulators, eventually to understand developmental process or tissue-specific functions

    Scale dependence of quark mass matrices in models with flavor symmetries

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    Numerical correlations between fermion masses and mixings could indicate the presence of a flavor symmetry at high energies. In general, the search for these correlations using low-energy data requires an estimate of leading-log radiative corrections. We present a complete analysis of the evolution between the electroweak and the grand unification scales of quark mass parameters in minimal supersymmetric models. We take Mt=180M_t=180 GeV and consider all possible values of tanβ\tan \beta. We also analize the possibility that the {\it top} and/or the {\it bottom} Yukawa couplings result from an intermediate quasifixed point (QFP) of the equations. We show that the quark mixings of the third family do {\it not} have a QFP behaviour (in contrast to the masses, the renormalization of all the mixings is linear), and we evaluate the low-energy value of VubV_{ub} which corresponds to Vub(MX)=0V_{ub}(M_X)=0. Then we focus on the renormalization-group corrections to {\it (i)} typical relations obtained in models with flavor symmetries at the unification scale and {\it (ii)} a superstring-motivated pattern of quark mass matrices. We show that in most of the models the numerical prediction for VubV_{ub} can be {\it corrected} in both directions (by varying tanβ\tan\beta) due to {\it top} or {\it bottom} radiative corrections.Comment: LaTeX, 14 pages, 4 figures, 3 tables. Uses epsf.sty. PostScript available at http://deneb.ugr.es/papers/ugft60.ps.gz Plain LaTeX, Positions of the figures corrected agai

    Predictive fermion mass matrix ansatzes in non-supersymmetric SO(10) grand unification

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    We investigate the status of predictive fermion mass ansatzes which make use of the grand unification scale conditions me=md/3m_e=m_d/3, mμ=3msm_\mu =3m_s, and Vcb=mc/mt\mid V_{cb}\mid =\sqrt{m_{c}/m_{t}} in non-supersymmetric SO(10) grand unification. The gauge symmetry below an intermediate symmetry breaking scale MIM_I is assumed to be that of the standard model with either one Higgs doublet or two Higgs doublets . We find in both cases that a maximum of 5 standard model parameters may be predicted within 1σ1\sigma experimental ranges. We find that the standard model scenario predicts the low energy Vcb\mid V_{cb}\mid to be in a range which includes its experimental mid-value 0.044 and which for a large top mass can extend to lower values than the range resulting in the supersymmetric case. In the two Higgs standard model case, we identify the regions of parameter space for which unification of the bottom quark and tau lepton Yukawa couplings is possible at grand unification scale. In fact, we find that unification of the top, bottom and tau Yukawa couplings is possible with the running b-quark mass within the 1σ1\sigma preferred range mb=4.25±0.1GeVm_b=4.25\pm 0.1\, GeV provided α3c(MZ)\alpha_{3c}(M_Z) is near the low end of its allowed range. In this case, one may make 6 predictions which include Vcb\mid V_{cb}\mid within its 90%90\% confidence limits. However unless the running mass mb>4.4GeVm_b>4.4\, GeV, third generation Yukawa coupling unification requires the top mass to be greater thanComment: 30 pages, 8 figures available on request from [email protected], Late

    Measurement of the Branching Fraction for B- --> D0 K*-

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    We present a measurement of the branching fraction for the decay B- --> D0 K*- using a sample of approximately 86 million BBbar pairs collected by the BaBar detector from e+e- collisions near the Y(4S) resonance. The D0 is detected through its decays to K- pi+, K- pi+ pi0 and K- pi+ pi- pi+, and the K*- through its decay to K0S pi-. We measure the branching fraction to be B.F.(B- --> D0 K*-)= (6.3 +/- 0.7(stat.) +/- 0.5(syst.)) x 10^{-4}.Comment: 7 pages, 1 postscript figure, submitted to Phys. Rev. D (Rapid Communications
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