Local spillovers, production technology and the choice to make and/or buy. Empirical evidence from Emilia Romagna

By exploiting a new rich firm-level dataset, this paper investigates the decision to subcontract production activities (outsourcing) with respect to vertically integrate them. In particular, we aim at identifying the main factors underlying the decision to either fully or partially decentralise production activities by mechanical firms located in Emilia Romagna (Italy). In so doing, we first account for firm characteristics, such as size, age and the skill composition of the labour force, then we focus on labour costs per employee, product diversity and the presence of the firm on international markets. Finally, and differently from previous research, we include in the analysis both the qualitative composition of the production process, as given by the stages of production potentially developed by the firm, and the industrial composition of the local market. On this last purpose, we estimate the relationship between the propensity and the intensity of concurrent and total sourcing and the main sources of agglomeration economies identified in the literature: specialisation economies, variety and urbanisation economies. Our estimates show a particularly strong and positive relation between the intensity of 'pure' outsourcing and our measure of variety, workforce skill intensity and the internal composition of production, while a negative relation emerges with respect to firm size, age and labour cost. Results concerning concurrent sourcing, instead, appear weaker, but, differently from the case of full outsourcing, we nd a positive relationship with rm size and product diversity.

Child brides: the age estimation problem in young girls

The aim of this work is to study a sample of girls from 15 different countries using Third Molar Maturity Index (I3M ), to assess the probability that a girl has reached the legal age of 18 years. The studied sample consisted of 3228 Orthopantomograms of healthy female subjects from 15 different countries. The cut- off value of I3M = 0.08 was tested to discriminate adults (≥18 years) and minors (<18 years). X-ray images were processed by computer-aided drafting program ImageJ. The information on sensitivity and specificity of I3M coming from the 15 countries was pooled together using a bivariate Bayesian modeling approach. Specificity of the I3M test did not change when the country was considered, and its value remains greater than 85% for each studied country. This method is useful to estimate the age of the girls involved in suspected early marriage because of the high probability of correctly identifying a minor with similar results observed among tested populations

Towards a Model-Based Field-Frequency Lock for Fast-Field Cycling NMR

Fast-field cycling nuclear magnetic resonance (FFC NMR) relaxometry allows to investigate molecular dynamics of complex materials. FFC relaxometry experiments require the magnetic field to reach different values in few milliseconds and field oscillations to stay within few ppms during signal acquisition. Such specifications require the introduction of a novel field-frequency lock (FFL) system. In fact, control schemes based only on current feedback may not guarantee field stability, while standard FFLs are designed to handle very slow field fluctuations, such as thermal derives, and may be ineffective in rejecting faster ones. The aim of this work is then to propose a methodology for the synthesis of a regulator that guarantees rejection of field fluctuations and short settling time. Experimental trials are performed for both model validation and evaluation of the closed-loop performances. Relaxometry experiments are performed to verify the improvement obtained with the new FFL. The results highlight the reliability of the model and the effectiveness of the overall approach

DFT insights into the oxygen-assisted selective oxidation of benzyl alcohol on manganese dioxide catalysts

The reactivity pattern of the MnO2 catalyst in the selective aerobic oxidation of benzyl alcohol is assessed by density functional theory (DFT) analysis of adsorption energies and activation barriers on a model Mn4O8 cluster. DFT calculations predict high reactivity of defective Mn(IV) sites ruling a surface redox mechanism, L-H type, involving gas-phase oxygen. Bare and promoted (i.e., CeOx and FeOx) MnOx materials with high surface exposure of Mn(IV) sites were synthesized to assess kinetic and mechanistic issues of the selective aerobic oxidation of benzyl alcohol on real catalysts (T, 333- 363K). According to DFT predictions, the experimental study shows: i) comparable activity of bare and promoted catalysts due to surface Mn(IV) sites; ii) the catalytic role of oxygen-atoms in the neighboring of active Mn(IV) sites; and iii) a 0th-order dependence on alcohol concentration, diagnostic of remarkable influence of adsorption phenomena on the reactivity pattern. Evidences of catalyst deactivation due to the over-oxidation of benzyl alcohol to benzoic acid, acting as poison of the active sites, are discussed

Determination of total vanadium and vanadium(V) in groundwater from Mt. Etna and estimate of daily intake of vanadium(V) through drinking water.

Vanadium(V) can be found in natural waters in the form of V(IV) and V(V) species, which have different biological properties and toxicity. The purpose of this study was to determine the concentrations of total V and V(V) in groundwater from the area of Mt. Etna and to assess the estimated daily intake (EDI) of V(V) of adults and children through drinking water. Water was sampled monthly at 21 sites in 2011. Total vanadium was determined by inductively coupled plasma-mass spectrometry (ICP-MS) and speciation by ion chromatography-ICP-MS (IC-ICP-MS). The concentration of V(V) species ranged from 62.8 to 98.9% of total V, with significantly higher concentrations in samples from the S/SW slope of Mt. Etna. The annual mean concentrations of total V exceeded the Italian legal limit of 140 μg/L at four sites on the S/SW slope. In the absence of thresholds for V(V) intake, only the Environmental Protection Agency (EPA) has calculated a reference dose. Children's EDI of V(V) at the sites with the higher V concentrations exceeded EPA thresholds (9 μg/kg/day). In particular, we found in Camporotondo, Mascalucia, Ragalna and San Pietro Clarenza sites children's EDIs of 11, 9.3, 11 and 9.9, respectively. The EDI of V(V) was significantly higher than the literature range (0.09–0.34 μg/kg/day)

AN INVESTIGATION ON LOW-TEMPERATURE FLUIDIZED COMBUSTION OF LIQUID FUELS

ABSTRACT Presently, the combustion at low temperature is receiving a great deal of interest because emissions of micro-and nanopollutants are expected to be greatly reduced. Following previous studies on the low temperature combustion behavior, the authors report results and discussion of steady-state experiments on an atmospheric, pre-pilot scale, 140 mm ID, FB reactor, equipped with an under-bed, airassisted, liquid-fuel injector. The experimental program was focused on the operation at temperatures lower than the classical value for FBC of solid fuels (i.e., 850°C). The data series taken into consideration are the concentrations of the main unburned species in the splash zone, those of oxygen measured in the bed and in the splash zone as well as the freeboard pressure. The interpretation of the results is mainly based on the statistical analysis in the time domain. The combustion pattern of bio-diesel is compared to that of the diesel fuel under varying operating conditions (e.g., bed temperature, dispersion air velocity at the fuel nozzle, injector height in the bed). Conclusions that were previously published on the base of labscale results are checked against new data obtained on the pilot scale. An innovative technique for the analysis of the micro-explosive regime is presented. It consists in the comparison of oxygen concentration measured by the zirconia-based probes at different heights in the bed and in the splash region, pressure signals measured in the freeboard and purposely filtered, and video-recordings of the bed surface phenomena. INTRODUCTION From a viewpoint directed at application of fluidized bed combustion (FBC), conventional, petroleum-derived liquid fuels are usually not taken into consideration. Vice versa, the cheap biomass-derived liquid fuels are worth of being exploited, at least for some specific applications. The combustion at low temperature is presently receiving a great deal of interest in view of depressing emission of micro-and nano-pollutants. The operation of a fluidized bed combustor (FBC) at a temperature lower than the classical value for FBC of solid fuels (i.e., 850°C) presents a number of interesting issues the mechanisms of which are not completely revealed yet. The combustion of a liquid fuel in a fluidized bed can be considered as the result of a number of serial stages: atomization, vaporization, pyrolysis, mixing with air and oxidation, formation of pollutant. They occur in an ideal sequence moving from the fuel inlet port to the bed exit, provided that the residence time in the bed is long enough [2] at the laboratory scale, i.e., with an 80 mm ID fluidized combustor. They identified a combustion behavior at a bed temperature below 750°C that was described as &quot;regime with micro-explosions&quot;. Because of the periodic eruption of air bubbles the properties of th

Venous endotelin-1 (ET-1) and brain natriuretic peptide (BNP) plasma levels during 6-month bosentan treatment for pulmonary arterial hypertension

Objective: Bosentan, an endothelin (ET) ETA-ETB receptors antagonist, is an effective therapy for idiopathic pulmonary arterial hypertension (PAH) and for PAH related to connective tissue disease (CTD). The aim of this study was to evaluate the behaviour of ET-1 and brain natriuretic peptide (BNP) venous plasma levels during a 6-month dual ET-1 receptor blockade and the potential influence of baseline ET-1 venous plasma levels on the clinical efficacy of bosentan. Setting and patients: Twenty-five patients with PAH (idiopathic n = 16, CTD n = 9) in WHO functional class II-III were included in this study. After initial evaluation, patients' WHO class, 6-minute walking-test (6MWT), ET-1 and BNP venous plasma levels were assessed at baseline and after 6-month bosentan therapy. To evaluate whether the ET-1 levels could influence the clinical response to bosentan, data were analyzed for the whole population which was stratified according to high and low ET-1 plasma levels (on the basis of the baseline median value of ET-1 plasma: Gr.1 18.7 pg/ml). Results: Study population included patients with moderate-severe PAH. After 6-month of treatment we observed a significant increase in 6MWT distance (from 435 ± 85) m to 467 ± 77 m, p > 0.001) and an improvement in WHO class (from 2.4 ± 0.5 to 2 ± 0.6 p > 0.01), with a significant decrease in BNP (from 87 ± 33 pg/ml to 67 ± 41 pg/ml, p = 0.006) and a trend towards lower ET-1 plasma levels (from 17.7 ± 5 pg/ml to 16 ± 6 pg/ml, p = ns). Improvement in effort tolerance (Δ distance) was not correlated to modification in ET-1 (ΔET-1) and BNP (ΔBNP) plasma levels, while we found a significant correlation between ΔET-1 and ΔBNP (r = 0.63, p = 0.0006). Analyzing the subpopulation, Gr.2 patients were older (Gr.1: 41 ± 10 years vs Gr.2: 50 ± 9 years, p = 0.04), had less effort capacity (6MWT distance, Gr.1: 469 ± 76 m, vs Gr.2: 398 ± 82 m, p = 0.03), and showed a trend towards higher BNP values (Gr.1: 82 ± 41 pg/ml vs Gr.2: 92 ± 23 pg/ml, p = 0.051), but no significant differences in pulmonary hemodynamics. After the 6-month treatment both groups showed a significant improvement in 6MWT (Gr.1: + 32 ± 24 m, Gr.2: + 32 ± 21 m p = 0.05) without differences between groups. WHO class had a trend towards lower class (Gr.1: - 0.5 ± 0.5, Gr.2: - 0.3 ± 0.4 p = 0.15) in both groups. BNP plasma levels showed a significant decrease only in Gr.2 (Gr.1: - 6 ± 41 pg/ml, Gr.2: - 34 ± 19 pg/ml p = 0.02); similarly ET-1 plasma levels showed a trend towards a decrease only in Gr.2 (Gr.1: 0.2 ± 4.6 pg/ml, Gr.2: - 3.8 ± 6.6 pg/ml p = 0.09). Conclusions: Our data confirm that bosentan is an effective therapy for patients with PAH. Its clinical efficacy (effort tolerance and NYHA) seems to be independent from baseline venous ET1 plasma levels. Bosentan therapy seems to elicit different patterns in ET-1 and BNP plasma levels, with decrease of the peptides only in patients with higher activation of the systemic endothelin system. Further studies are warranted to explore the potential impact of baseline ET-1 levels on the long-term effects (clinical worsening) of bosentan therapy. © 2008 Elsevier B.V. All rights reserved

Dental Age Estimation of Growing Children: Comparison Among Various European Countries

Procjena dobi djece temeljno je pitanje u sudskoj medicini, pedijatrijskoj endokrinologiji i ortodontskom liječenju. Za to se koristi nekoliko metoda, uključujući i onu na osnovi razvoja kostiju i zuba. Budući da je nekoliko autora ustanovilo da se dentalne metode mogu razlikovati prema točnosti procjene, ovaj se rad temelji na poboljšanjima metode koju su razvili Cameriere i suradnici te ih proširuje na veći uzorak djece iz nekoliko europskih regija - 505 iz Italije, 304 s Kosova i 291 iz Slovenije. Također se ispitala učinkovitost metode u situacijama kada se različite populacije analiziraju zajedno. Koeficijenti korelacije procjenjivali su se između dobi i predvidivih varijabli. Statistička analiza obavljena je u statističkom programu S-PLUS 6 (SPLUS 6.1 za Windowsov operativni sustav - Professional Edition, Release 1). Razina znatnosti postavljena je na 5%. Statistička analiza pokazala je da spol, zbroj normalno otvorenih apeksa i broj zuba s potpuno razvijenim korjenovima znatno utječu na procjenu starosti. Pripadnost različitim europskim regijama nije utjecala na parametre modela.Age estimation in children is a fundamental question in forensic medicine, paediatric endocrinology and orthodontic treatment. Several methods deal with their age estimation, including methods based on bone and on tooth development. Since several authors have shown that odontological methods can differ in accuracy when different populations are considered, this paper focuses on improvement of the method developed by Cameriere et al., extending it to a larger sample of children belonging to several European regions - 505 Italian, 304 Kossovan and 291 Slovenian children, and investigates the efficiency of the method when various populations are pooled together. Correlation coefficients were evaluated between age and predictive variables. Statistical analysis was performed with the S-PLUS 6 statistical program (S-PLUS 6.1 for Windows, Professional Edition, Release 1). The significance threshold was set at 5%. Statistical analysis indicated that gender, sum of normalized open apices and number of teeth with complete root development have a significant influence on age estimation. Belonging to various European regions did not have a significant influence on model parameters