La "questione dimensionale" come problema organizzativo

The paper argues that the shape of the long-run size distribution of business firms is basically determined by the availability of organisational capabilities, and that its changes over time (the "direction" of change) depend on the way in which (exogenous) "environmental" conditions affect firms' decisions as to what extent the division of labour has to take place within their boundaries rather than being allocated through market transactions. In such perspective it is argued that the growth of firms brings about important changes in their internal shape, by involving the development of more and more "control" functions. In particular, in this connection Italian firms seem to be characterised, in the current phase of industrial development, by a tendency towards growing complexity, sub specie of the internalisation of a larger set of activities (other than production) with respect to the past.Firm Size Structure, Firm Growth and Organisation, Medium-Sized Firms, Division of Labour, Markets vs. Hierarchies, Organisational Change

Struttura industriale e architetture organizzative. Ipotesi sul "ritorno" della gerarchia

Firm size, Firm Growth; Industrial Structure; Polyarchies; Hierarchies; Italy

Geographical variation in the diet of the Antarctic fur seal <i>Arctocephalus gazella</i>

The diet of non-breeding male Antarctic fur seals Arctocephalus gazella was investigated at different localities of the Antarctic Peninsula (Cierva Point and Hope Bay), South Shetland Islands (Deception Island and Potter Peninsula) and the South Orkney Islands (Laurie Island), by the analysis of 438 scats collected from January to March 2000. The composition of the diet was diverse, with both pelagic and benthic-demersal prey represented in the samples. Antarctic krill Euphausia superba was the most frequent and numerous prey at all the study sites except at Cierva Point, followed by fish, penguins and cephalopods. Antarctic krill also predominated by mass, followed by either fish or penguins. Fish were the second most important prey by mass at the Antarctic Peninsula whereas penguins were the second most important prey by mass at the South Shetland and South Orkney Islands. Among fish, Pleuragramma antarcticum was the most important species in the diet of the Antarctic fur seals at the Antarctic Peninsula whereas Gymnoscopelus nicholsi predominated at the South Shetland and South Orkney Islands. The results are compared with previous studies, and the possibility of implementing monitoring studies on the distribution/abundance of myctophids and P. antarcticum based on the analysis of the diet of the Antarctic fur seal is considered.Facultad de Ciencias Naturales y MuseoFacultad de Ciencias Médica

Anionic glycolipids related to glucuronosyldiacylglycerol inhibit protein kinase Akt

New glucuronosyldiacylglycerol (GlcADG) analogues based on a 2-O-\u3b2-D-glucopyranosyl-sn-glycerol scaffold and carrying one or two acyl chains of different lengths have been synthesized as phosphatidylinositol 3-phosphate (PI3P) mimics targeting the protein kinase Akt. Akt inhibitory effect of prepared compounds, was assayed using an in vitro kinase assay. The antiproliferative activity of the compounds was tested in the human ovarian carcinoma IGROV-1 cell line in which we found that two of them could inhibit proliferation, in keeping with the target inhibitory effect

The effect of internal pressure on the tetragonal to monoclinic structural phase transition in ReOFeAs: the case of NdOFeAs

We report the temperature dependent x-ray powder diffraction of the quaternary compound NdOFeAs (also called NdFeAsO) in the range between 300 K and 95 K. We have detected the structural phase transition from the tetragonal phase, with P4/nmm space group, to the orthorhombic or monoclinic phase, with Cmma or P112/a1 (or P2/c) space group, over a broad temperature range from 150 K to 120 K, centered at T0 ~137 K. Therefore the temperature of this structural phase transition is strongly reduced, by about ~30K, by increasing the internal chemical pressure going from LaOFeAs to NdOFeAs. In contrast the superconducting critical temperature increases from 27 K to 51 K going from LaOFeAs to NdOFeAs doped samples. This result shows that the normal striped orthorhombic Cmma phase competes with the superconducting tetragonal phase. Therefore by controlling the internal chemical pressure in new materials it should be possible to push toward zero the critical temperature T0 of the structural phase transition, giving the striped phase, in order to get superconductors with higher Tc.Comment: 9 pages, 3 figure

Intrinsic phase separation in superconducting K0.8Fe1.6Se2 (Tc= 31.8 K) single crystals

Temperature dependent single-crystal x-ray diffraction (XRD) in transmission mode probing the bulk of the newly discovered K0.8Fe1.6Se2 superconductor (Tc = 31.8 K) using synchrotron radiation is reported. A clear evidence of intrinsic phase separation at 520 K between two competing phases, (i) a first majority magnetic phase with a ThCr2Si2-type tetragonal lattice modulated by the iron vacancy ordering and (ii) a minority non-magnetic phase having an in-plane compressed lattice volume and a weak superstructure, is reported. The XRD peaks due to the Fe vacancy ordering in the majority phase disappear by increasing the temperature at 580 K, well above phase separation temperature confirming the order-disorder phase transition. The intrinsic phase separation at 520K between a competing first magnetic phase and a second non-magnetic phase in the normal phase both having lattice superstructures (that imply different Fermi surface topology reconstruction and charge density) is assigned to a lattice-electronic instability of the K0.8Fe1.6Se2 system typical of a system tuned at a Lifshitz critical point of an electronic topological transition that gives a multi-gaps superconductor tuned a shape resonance.Comment: 10 pages, 4 figure

Sluggish investment, crisis and firm heterogeneity

The stagnation of investments and its causes have attracted great attention in the recent economic debate. In this paper, we show that during the Great Recession, the flattening of the capital formation rate at the firm level is not due to lower average propensity to invest. Rather, it is the result of growing heterogeneity of choices among firms. While a subset of firms is oriented towards increasing investments, another group substantially divest. The result is a polarization of conducts that tend to cancel each other out, resulting in a flattening of aggregate investment. We argue that this asymmetry in firm's decisions depends on two main factors. The first one is the diversity of corporate strategies, which firms have developed in the past. The second driver is managerial discretion, that plays an important role in the adoption of specific investment/divestment trajectories when faced with a recession. The results of our empirical analysis provide strong support for our hypotheses: after controlling for contextual and firm-specific structural, financial and demographic variables, corporate strategies and managerial discretion in the allocation of liquid assets explain large part of the heterogeneity in investment decisions during the recession. Policy implications are discussed