| 1. |
- Abelev, Betty, et al.
(författare)
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Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV
- 2013
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41
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Tidskriftsartikel (refereegranskat)abstract
- Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < P-T,P-assoc < P-T,P-trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p(T) bins, and the widths show no significant evolution with event multiplicity or p(T). These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
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| 2. |
- Abelev, Betty, et al.
(författare)
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Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :11
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Tidskriftsartikel (refereegranskat)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
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| 3. |
- Abelev, Betty, et al.
(författare)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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| 4. |
- DeAngelis, Nicola, et al.
(författare)
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2020 WSES guidelines for the detection and management of bile duct injury during cholecystectomy
- 2021
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Ingår i: World Journal of Emergency Surgery. - : BMC. - 1749-7922. ; 16:1
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Forskningsöversikt (refereegranskat)abstract
- Bile duct injury (BDI) is a dangerous complication of cholecystectomy, with significant postoperative sequelae for the patient in terms of morbidity, mortality, and long-term quality of life. BDIs have an estimated incidence of 0.4-1.5%, but considering the number of cholecystectomies performed worldwide, mostly by laparoscopy, surgeons must be prepared to manage this surgical challenge. Most BDIs are recognized either during the procedure or in the immediate postoperative period. However, some BDIs may be discovered later during the postoperative period, and this may translate to delayed or inappropriate treatments. Providing a specific diagnosis and a precise description of the BDI will expedite the decision-making process and increase the chance of treatment success. Subsequently, the choice and timing of the appropriate reconstructive strategy have a critical role in long-term prognosis. Currently, a wide spectrum of multidisciplinary interventions with different degrees of invasiveness is indicated for BDI management. These World Society of Emergency Surgery (WSES) guidelines have been produced following an exhaustive review of the current literature and an international expert panel discussion with the aim of providing evidence-based recommendations to facilitate and standardize the detection and management of BDIs during cholecystectomy. In particular, the 2020 WSES guidelines cover the following key aspects: (1) strategies to minimize the risk of BDI during cholecystectomy; (2) BDI rates in general surgery units and review of surgical practice; (3) how to classify, stage, and report BDI once detected; (4) how to manage an intraoperatively detected BDI; (5) indications for antibiotic treatment; (6) indications for clinical, biochemical, and imaging investigations for suspected BDI; and (7) how to manage a postoperatively detected BDI.
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| 5. |
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| 6. |
- Aliaga, Diego, et al.
(författare)
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Identifying source regions of air masses sampled at the tropical high-altitude site of Chacaltaya using WRF-FLEXPART and cluster analysis
- 2021
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 21:21, s. 16453-16477
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Tidskriftsartikel (refereegranskat)abstract
- Observations of aerosol and trace gases in the remote troposphere are vital to quantify background concentrations and identify long-term trends in atmospheric composition on large spatial scales. Measurements made at high altitude are often used to study free-tropospheric air; however such high-altitude sites can be influenced by boundary layer air masses. Thus, accurate information on air mass origin and transport pathways to high-altitude sites is required. Here we present a new method, based on the source-receptor relationship (SRR) obtained from backwards WRF-FLEXPART simulations and a k-means clustering approach, to identify source regions of air masses arriving at measurement sites. Our method is tailored to areas of complex terrain and to stations influenced by both local and long-range sources. We have applied this method to the Chacaltaya (CHC) GAW station (5240 m a.s.l.; 16.35 degrees S, 68.13 degrees W) for the 6-month duration of the Southern Hemisphere high-altitude experiment on particle nucleation and growth (SALILNA) to identify where sampled air masses originate and to quantify the influence of the surface and the free troposphere. A key aspect of our method is that it is probabilistic, and for each observation time, more than one air mass (cluster) can influence the station, and the percentage influence of each air mass can be quantified. This is in contrast to binary methods, which label each observation time as influenced by either boundary layer or free-troposphere air masses. Air sampled at CHC is a mix of different provenance. We find that on average 9 % of the air, at any given observation time, has been in contact with the surface within 4 d prior to arriving at CHC. Furthermore, 24 % of the air has been located within the first 1.5 km above ground level (surface included). Consequently, 76 % of the air sampled at CHC originates from the free troposphere. However, pure free-tropospheric influences are rare, and often samples are concurrently influenced by both boundary layer and free-tropospheric air masses. A clear diurnal cycle is present, with very few air masses that have been in contact with the surface being detected at night. The 6-month analysis also shows that the most dominant air mass (cluster) originates in the Amazon and is responsible for 29 % of the sampled air. Furthermore, short-range clusters (origins within 100 km of CHC) have high temporal frequency modulated by local meteorology driven by the diurnal cycle, whereas the mid- and long-range clusters' (> 200 km) variability occurs on timescales governed by synoptic-scale dynamics. To verify the reliability of our method, in situ sulfate observations from CHC are combined with the SRR clusters to correctly identify the (pre-known) source of the sulfate: the Sabancaya volcano located 400 km north-west from the station.
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| 7. |
- Almeida, Joao, et al.
(författare)
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Molecular understanding of sulphuric acid-amine particle nucleation in the atmosphere
- 2013
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 502:7471, s. 359-
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Tidskriftsartikel (refereegranskat)abstract
- Nucleation of aerosol particles from trace atmospheric vapours is thought to provide up to half of global cloud condensation nuclei(1). Aerosols can cause a net cooling of climate by scattering sunlight and by leading to smaller but more numerous cloud droplets, which makes clouds brighter and extends their lifetimes(2). Atmospheric aerosols derived from human activities are thought to have compensated for a large fraction of the warming caused by greenhouse gases(2). However, despite its importance for climate, atmospheric nucleation is poorly understood. Recently, it has been shown that sulphuric acid and ammonia cannot explain particle formation rates observed in the lower atmosphere(3). It is thought that amines may enhance nucleation(4-16), but until now there has been no direct evidence for amine ternary nucleation under atmospheric conditions. Here we use the CLOUD (Cosmics Leaving OUtdoor Droplets) chamber at CERN and find that dimethylamine above three parts per trillion by volume can enhance particle formation rates more than 1,000-fold compared with ammonia, sufficient to account for the particle formation rates observed in the atmosphere. Molecular analysis of the clusters reveals that the faster nucleation is explained by a base-stabilization mechanism involving acid-amine pairs, which strongly decrease evaporation. The ion-induced contribution is generally small, reflecting the high stability of sulphuric acid-dimethylamine clusters and indicating that galactic cosmic rays exert only a small influence on their formation, except at low overall formation rates. Our experimental measurements are well reproduced by a dynamical model based on quantum chemical calculations of binding energies of molecular clusters, without any fitted parameters. These results show that, in regions of the atmosphere near amine sources, both amines and sulphur dioxide should be considered when assessing the impact of anthropogenic activities on particle formation.
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| 8. |
- Beck, Lisa J., et al.
(författare)
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Differing Mechanisms of New Particle Formation at Two Arctic Sites
- 2021
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Ingår i: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 48:4
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Tidskriftsartikel (refereegranskat)abstract
- New particle formation in the Arctic atmosphere is an important source of aerosol particles. Understanding the processes of Arctic secondary aerosol formation is crucial due to their significant impact on cloud properties and therefore Arctic amplification. We observed the molecular formation of new particles from low-volatility vapors at two Arctic sites with differing surroundings. In Svalbard, sulfuric acid (SA) and methane sulfonic acid (MSA) contribute to the formation of secondary aerosol and to some extent to cloud condensation nuclei (CCN). This occurs via ion-induced nucleation of SA and NH3 and subsequent growth by mainly SA and MSA condensation during springtime and highly oxygenated organic molecules during summertime. By contrast, in an ice-covered region around Villum, we observed new particle formation driven by iodic acid but its concentration was insufficient to grow nucleated particles to CCN sizes. Our results provide new insight about sources and precursors of Arctic secondary aerosol particles.
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| 9. |
- Bertani, Federico, et al.
(författare)
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Triptycene-Roofed Quinoxaline Cavitands for the Supramolecular Detection of BTEX in Air
- 2016
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Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 22, s. 3312-3319
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Tidskriftsartikel (refereegranskat)abstract
- Two novel triptycene quinoxaline cavitands (DiTriptyQxCav and MonoTriptyQxCav) have been designed, synthesized, and applied in the supramolecular detection of benzene, toluene, ethylbenzene, and xylenes (BTEX) in air. The complexation properties of the two cavitands towards aromatics in the solid state are strengthened by the presence of the triptycene moieties at the upper rim of the tetraquinoxaline walls, promoting the confinement of the aromatic hydrocarbons within the cavity. The two cavitands were used as fiber coatings for solid‐phase microextraction (SPME) BTEX monitoring in air. The best performances in terms of enrichment factors, selectivity, and LOD (limit of detection) values were obtained by using the DiTriptyQxCav coating. The corresponding SPME fiber was successfully tested under real urban monitoring conditions, outperforming the commercial divinylbenzene–Carboxen–polydimethylsiloxane (DVB–CAR–PDMS) fiber in BTEX adsorption.
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| 10. |
- Bianchi, Federico, et al.
(författare)
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Highly Oxygenated Organic Molecules (HOM) from Gas-Phase Autoxidation Involving Peroxy Radicals : A Key Contributor to Atmospheric Aerosol
- 2019
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Ingår i: Chemical Reviews. - : American Chemical Society (ACS). - 0009-2665 .- 1520-6890. ; 119:6, s. 3472-3509
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Forskningsöversikt (refereegranskat)abstract
- Highly oxygenated organic molecules (HOM) are formed in the atmosphere via autoxidation involving peroxy radicals arising from volatile organic compounds (VOC). HOM condense on pre-existing particles and can be involved in new particle formation. HOM thus contribute to the formation of secondary organic aerosol (SOA), a significant and ubiquitous component of atmospheric aerosol known to affect the Earths radiation balance. HOM were discovered only very recently, but the interest in these compounds has grown rapidly. In this Review, we define HOM and describe the currently available techniques for their identification/quantification, followed by a summary of the current knowledge on their formation mechanisms and physicochemical properties. A main aim is to provide a common frame for the currently quite fragmented literature on HOM studies. Finally, we highlight the existing gaps in our understanding and suggest directions for future HOM research.
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| 11. |
- Bianchi, Federico, et al.
(författare)
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The peer review game : an agent-based model of scientists facing resource constraints and institutional pressures
- 2018
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Ingår i: Scientometrics. - : Springer. - 0138-9130 .- 1588-2861. ; 116:3, s. 1401-1420
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Tidskriftsartikel (refereegranskat)abstract
- This paper looks at peer review as a cooperation dilemma through a game-theory framework. We built an agent-based model to estimate how much the quality of peer review is influenced by different resource allocation strategies followed by scientists dealing with multiple tasks, i.e., publishing and reviewing. We assumed that scientists were sensitive to acceptance or rejection of their manuscripts and the fairness of peer review to which they were exposed before reviewing. We also assumed that they could be realistic or excessively over-confident about the quality of their manuscripts when reviewing. Furthermore, we assumed they could be sensitive to competitive pressures provided by the institutional context in which they were embedded. Results showed that the bias and quality of publications greatly depend on reviewer motivations but also that context pressures can have a negative effect. However, while excessive competition can be detrimental to minimising publication bias, a certain level of competition is instrumental to ensure the high quality of publication especially when scientists accept reviewing for reciprocity motives.
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| 12. |
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| 13. |
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| 14. |
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| 15. |
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| 16. |
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| 17. |
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| 18. |
- Bianchi, Mattia, et al.
(författare)
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Organizing for External Technology Commercialization: evidence from a multiple case study in the pharmaceutical industry
- 2011
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Ingår i: R&D Management. - : Wiley: 24 months. - 0033-6807. ; 41:2, s. 120-137
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Tidskriftsartikel (refereegranskat)abstract
- External technology commercialization (ETC) is increasingly being regarded as a strategic priority by companies. ETC is the use of out-licensing to transfer technologies that are disembodied from products to other organizations. Previous research has focused on the economic and strategic dimensions but little attention has so far been paid to how ETC should be organized. This paper explores whether and how firms operating in different contexts adopt dissimilar organizational solutions for their ETC activities. To this aim, a theoretical framework is first developed that comprises the key constitutive elements of ETC organization and a number of firm-level and deal-level factors that are supposed to influence organizational design choices. Based on a multiple case-study analysis involving 16 out-licensing deals executed in seven Italian pharmaceutical firms, the paper shows that the organization of out-licensing tasks and the allocation of decision-making power is shaped by, and adapts to, the relevance of ETC in the corporate strategy, the volume of ETC transactions, the stage of development of the technology being commercialized and the competitive threats due to the deal. The paper is believed to be useful for licensing and R&D managers who can find practical insights into how ETC activities can be organized and which critical contextual factors should be accounted for when designing such organization.
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| 19. |
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| 20. |
- Bianchi, Mattia, et al.
(författare)
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Selling technological knowledge: Managing the complexities of technology transactions
- 2011
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Ingår i: Research-Technology Management. - : Taylor & Francis (Routledge): SSH Titles. - 0895-6308. ; 54:2, s. 18-26
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Tidskriftsartikel (refereegranskat)abstract
- With the diffusion of the open-innovation paradigm, more companies are selling their technological knowledge, disembodied from physical artifacts, to other organizations in an attempt to maximize the rent-yield potential of the innovation process. However, extracting revenues from technology sale remains a challenge for most firms due to the peculiarities of technological knowledge as an object of commerce. A study of 30 companies actively involved in technology sale and 75 single transactions illuminates two key aspects of technology transactions: (1) the challenges that the technology sale process entails, and (2) the practices that can be adopted to manage the complexities of technology transactions. CTOs and R&D and technology managers can use these insights to build a firm-level capability in selling technological knowledge.
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| 21. |
- Bianchi, Mattia, et al.
(författare)
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Technology acquisition in family and nonfamily firms : A longitudinal analysis of spanish manufacturing firms
- 2013
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Ingår i: Journal of Product Innovation Management. - : Wiley: 24 months. - 1540-5885 .- 0737-6782. ; 30:6, s. 1073-1088
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Tidskriftsartikel (refereegranskat)abstract
- Technology acquisition from external sources has been identified as a critical competence for sustained success in innovation, and research has paid a good deal of attention to studying its advantages, drawbacks, determinants, and outcomes. Traditionally, research has modeled the choice to acquire technology from outside a firm's boundaries as the result of a trade-off between the benefits of external acquisition (e.g., higher return on investment, lower costs, increased flexibility, access to specialized skill sets, and creativity) and its drawbacks (e.g., opening the market to new entrants, risk of imitation of core competencies, and reduced value appropriability). Yet, this view does not capture the behavioral considerations that may potentially encourage or discourage managers from sourcing technology outside the firm's boundaries. This behavioral aspect is especially important if one wants to understand the conduct in external technology acquisition of family firms, which are found to favor strategic actions that preserve the controlling families' control and authority over business, even at the cost of giving up potential economic benefits. Thus, external technology acquisition is likely to be interpreted differently in family and nonfamily firms. Despite its importance, how the involvement of a controlling family affects decisions in technology and innovation management and specifically external technology acquisition is an overlooked topic in extant research and requires further theoretical and empirical examination. This study attempts to fill these gaps by extending the tenets of the behavioral agency model and prior research pointing to particularistic decision-making in family firms to uncover the behavioral drivers of external technology acquisition in family and nonfamily firms. Theory is developed that relates performance risk, family management, and the contingent effect of the degree of technology protection on external technology acquisition, and the hypotheses are tested with longitudinal data on 1540 private Spanish manufacturing firms. The analyses show that managers are more likely to acquire technology from external sources through research and development contracting when firm performance falls below managers' aspirations. Family firms are generally more reluctant to acquire external technology, and the effect of negative aspiration performance gaps becomes less relevant as family management is higher, which is attributed to family managers' attempts to avoid losing control over the trajectory that technology follows over time. However, family firms become more favorable to considering the adoption of an open approach to technology development when some protection mechanisms (specifically, the filing of patents on the firm proprietary technologies) increase the managers' perceptions of control over the technology trajectory. As such, this study makes a contribution to the understanding of the behavioral factors driving external technology acquisition, and it offers important insights regarding technology strategy in family firms.
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| 22. |
- Bianchi, Mattia, et al.
(författare)
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Technology exploitation paths : Combining technological and complementary resources in new product development and licensing
- 2014
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Ingår i: Journal of Product Innovation Management. - : Wiley: 24 months. - 1540-5885 .- 0737-6782. ; 31:S1, s. 146-169
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Tidskriftsartikel (refereegranskat)abstract
- Technological resources in the form of patents, trade secrets, and know-how have become key assets for modern enterprises. This paper addresses a critical issue in technology and innovation management, namely, the commercial exploitation of technological resources resulting from research and development (R&D) investments. Extracting economic value from these resources by maximizing the benefits for shareholders is an extremely challenging task because technological resources are intangible, idiosyncratic, uncertain, predominantly tacit, and with poorly defined property rights. In their attempt to extract the maximum value from their technological resources, firms increasingly combine their internal exploitation through new product development (NPD) with external exploitation through licensing. However, most existing studies on NPD and technology licensing have treated the two exploitation paths independently and in isolation, which has resulted in two separate research streams using different theories and addressing different managerial challenges. The purpose of this paper is to contribute to filling this gap by developing and testing a comprehensive conceptual framework that simultaneously considers the antecedents affecting the successful implementation of NPD and licensing strategies as well as their consequences on firm profitability. The paper in particular investigates the effects of the interplay between technological resources and three types of complementary resources, marketing, manufacturing, and relational. We test the model using structural equation modeling on a sample of 733 Spanish manufacturing firms observed from 2003 to 2007. The data provide support for the existence of different paths to market firm technologies: an internal path, whereby the ownership of technological resources fully explains NPD performance, and an external path, whereby high intensity of marketing and relational resources reinforces the positive effect of technological resources on licensing performance. This sustains the relevance of the resource-based value-enhancing effects of complementary resources in licensing, as opposed to the motivation-reducing effects advanced by transaction cost-based literature. Moreover, the empirical analysis shows a substitution effect between NPD and licensing, whereby their simultaneous pursuit at intense levels is associated with lower profit margins. This provides evidence of the much theorized, but seldom tested, rent dissipation effect. These findings offer several contributions to research on licensing, NPD, open innovation, and the resource-based view of the firm. On a managerial level, they suggest that achieving maximum value from proprietary technologies may not entail exploiting them both through external and internal paths. Managers are also informed that the resource combinations that enhance licensing performance include marketing and relational resources.
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| 23. |
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| 24. |
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| 25. |
- Bianchi, Mattia, et al.
(författare)
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Towards a phenotype of the amphibious company: an illustrative case from the chemical industry
- 2011
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Ingår i: Journal of Business Chemistry. - : Institute of Business Administration. - 1613-9623 .- 1613-9615. ; 8:1, s. 5-16
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Tidskriftsartikel (refereegranskat)abstract
- The paper explores the phenotype of the amphibious company, which is intended as the fittest economic species in today’s hypercompetitive business arenas and hence the most likely to survive and prosper. Four behavioral traits are proposed and discussed as distinctive of amphibious companies: doing different jobs good, diversifying in multiple market arenas, brokering and bridging across business networks and absorbing knowledge from the outside. The paper illustrates these arguments through a paradigmatic case study of an Italian firm operating in the chemical industry, which has been able to survive a challenging crisis by adopting an amphibious behavior.
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