Firms’ growth, size and age: a nonparametric approach

This paper offers empirical evidence of firm failure rates as well as the mean of the distribution of realized growth rates, distinguishing between the sample of non-failing firms and the sample of all firms, failing and non-failing. Attention is directed at identifying a set of characteristics, in particular the size and age of firms, systematically related to the patterns of firm growth and exit, using a panel of Spanish manufacturing firms. The two main contributions of the paper are the use of nonparametric techniques and the analysis of issues ignored in other studies like the regression-to-the-mean bias and the measurement of learning effects. We find evidence that failure rates and the mean growth rate of successful firms decline with size and age. When failing firms are integrated, there are no significant differences in the mean growth rate across the age and size of firms. Regression-to-the-mean does not prove to be a substantial factor behind the negative relationship between size and growth of surviving firms

Automatic supervision of gestures to guide novice surgeons during training

The final publication is available at Springer via http://dx.doi.org/10.1007/s00464-013-3285-9Background Virtual surgery simulators enable surgeons to learn by themselves, shortening their learning curves. Virtual simulators offer an objective evaluation of the surgeon’s skills at the end of each training session. The considered evaluation parameters are based on the analysis of the surgeon’s gestures performed throughout the training session. Currently, this information is usually known by surgeons only at the end of the training session, but very limited during the training performance. In this paper, we present a novel method for automatic and interactive evaluation of the surgeon’s skills that is able to supervise inexperienced surgeons during their training session with surgical simulators. Methods The method is based on the assumption that the sequence of gestures carried out by an expert surgeon in the simulator can be translated into a sequence (a character string) that should be reproduced by a novice surgeon during a training session. In this work, a string-matching algorithm has been modified to calculate the alignment and distance between the sequences of both expert and novice during the training performance. Results The results have shown that it is possible to distinguish between different skill levels at all times during the surgical training session. Conclusions The main contribution of this paper is a method where the difference between an expert’s sequence of gestures and a novice’s ongoing sequence is used to guide inexperienced surgeons. This is possible by indicating to novices the gesture corrections to be applied during surgical training as continuous expert supervision would do.Monserrat, C.; Lucas, A.; Hernández Orallo, J.; Rupérez Moreno, MJ. (2014). Automatic supervision of gestures to guide novice surgeons during training. Surgical Endoscopy. 28(4):1360-1370. doi:10.1007/s00464-013-3285-9S13601370284Ericsson KA (ed) (2009) Development of professional expertise: toward measurement of expert performance and design of optimal learning environments. Cambridge University Press, New YorkMcGaghie WC (2008) Research opportunities in simulation-based medical education using deliberate practice. Acad Emerg Med 15:995–1001Ericsson KA (2008) Deliberate practice and acquisition of expert performance: a general overview. Acad Emerg Med 15:988–994Issenberg SB, McGaghie WC, Petrusa ER et al (2005) Features and uses of high-fidelity medical simulations that lead to effective learning: a BEME systematic review. Med Teach 27:10–28Porte MC, Xeoulis G, Reznick RK, Dubrowski A (2007) Verbal feedback from an expert is more effective than self-accessed feedback about motion efficiency in learning new surgical skills. 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In: IEEE international conference on robotics and biomimetics (ROBIO), Tianjin, pp 247–252. doi: 10.1109/ROBIO.2010.5723335Chmarra MK, Klein S, Winter JCF, Jansen FW, Dankelman J (2010) Objective classification of residents based on their psychomotor laparoscopic skills. Surg Endosc 24(5):1031–1039. doi: 10.1007/s00464-009-0721-yLin HC, Shafran I, Yuh D, Hager GD (2006) Towards automatic skill evaluation: detection and segmentation of robot-assisted surgical motions. Comput Aided Surg 11(5):220–230. doi: 10.3109/10929080600989189Rosen J, Brown JD, Chang L, Sinanan MN, Hannaford B (2006) Generalized approach for modeling minimally invasive surgery as a stochastic process using a discrete Markov model. IEEE Trans Biomed Eng 53(3):399–413. doi: 10.1109/TBME.2005.869771Lahanas V, Loukas C, Nikiteas N, Dimitroulis D, Georgiou E (2011) Psychomotor skills assessment in laparoscopic surgery using augmented reality scenarios. In: 17th international conference on digital signal processing (DSP), Corfu. doi: 10.1109/ICDSP.2011.6004893Leong JJ et al (2006) HMM assessment of quality of movement trajectory in laparoscopic surgery. In: International conference on medical image computing and computer-assisted intervention (MICCAI’06), pp 752–759. doi: 10.3109/10929080701730979Megali G, Sinigaglia S, Tonet O, Dario P (2006) Modelling and evaluation of surgical performance using Hidden Markov models. IEEE Trans Biomed Eng 53(10):1911–1919. doi: 10.1109/TBME.2006.881784Huang J, Payandeh S, Doris P, Hajshirmohammadi I (2005) Fuzzy classification: towards evaluating performance on a surgical simulator. Stud Health Technol Inform 111:194–200Hajshirmohammadi I, Payandeh S (2007) Fuzzy set theory for performance evaluation in a surgical simulator. Presence 16(6):603–622. doi: 10.1162/pres.16.6.603Ukkonen E (1985) Algorithms for approximate string matching. 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Towards a clinical staging for bipolar disorder: defining patient subtypes based on functional outcome.

BACKGROUND: The functional outcome of Bipolar Disorder (BD) is highly variable. This variability has been attributed to multiple demographic, clinical and cognitive factors. The critical next step is to identify combinations of predictors that can be used to specify prognostic subtypes, thus providing a basis for a staging classification in BD. METHODS: Latent Class Analysis was applied to multiple predictors of functional outcome in a sample of 106 remitted adults with BD. RESULTS: We identified two subtypes of patients presenting "good" (n=50; 47.6%) and "poor" (n=56; 52.4%) outcome. Episode density, level of residual depressive symptoms, estimated verbal intelligence and inhibitory control emerged as the most significant predictors of subtype membership at the p<0.05 level. Their odds ratio (OR) and confidence interval (CI) with reference to the "good" outcome group were: episode density (OR=4.622, CI 1.592-13.418), level of residual depressive symptoms (OR=1.543, CI 1.210-1.969), estimated verbal intelligence (OR=0.969; CI 0.945-0.995), and inhibitory control (OR=0.771, CI 0.656-0.907). Age, age of onset and duration of illness were comparable between prognostic groups. LIMITATIONS: The longitudinal stability or evolution of the subtypes was not tested. CONCLUSIONS: Our findings provide the first empirically derived staging classification of BD based on two underlying dimensions, one for illness severity and another for cognitive function. This approach can be further developed by expanding the dimensions included and testing the reproducibility and prospective prognostic value of the emerging classes. Developing a disease staging system for BD will allow individualised treatment planning for patients and selection of more homogeneous patient groups for research purposes

The Scope, Scale and Locational Preferences of Spanish Multinationals

This paper examines the relationship between firms’ heterogeneity and their multinational activity. We examine the scope and the scale of multinational firms following the insights of Yeaple’s (2009) model. The goal of the paper is to contribute to a better understanding of the activity of Spanish multinationals using a sample of Spanish multinational firms. Our dataset is built from two databases, SABI and ORBIS, both from the Bureau van Dijk. Our results confirm that more productive firms have a greater multinational activity in terms of both the scope (the number of foreign markets where they invest) and the scale (the volume of local sales by subsidiaries in foreign markets). The structure of Spanish multinational firms’ activity is also analysed from the perspective of host country characteristics (GDP, population, distance and language) using standard gravity equations. Country characteristics that are positively associated (GDP and common language) with the volume of multinational activity are negatively related to the productivity of firms that go abroad. This asymmetry also holds for bilateral characteristics as distance that appears negatively associated with the level of multinational activity

Liver toxicity and risk of discontinuation in HIV/hepatitis C virus-coinfected patients receiving an etravirine-containing antiretroviral regimen: influence of liver fibrosis

Short communication[Abstract] Objectives. The aim of the study was to establish the risk of liver toxicity in HIV/hepatitis C virus (HCV)-coinfected patients receiving etravirine, according to the degree of liver fibrosis. Methods. A prospective cohort study of 211 HIV-infected patients initiating an etravirine-containing regimen was carried out. HCV coinfection was defined as a positive HCV RNA test, and baseline liver fibrosis was assessed by transient elastography. Hepatotoxicity was defined as clinical symptoms, or an aspartate aminotransferase (AST) or alanine aminotransferase (ALT) value > 5-fold higher than the upper limit of normal if baseline values were normal, or 3.5-fold higher if values were altered at baseline. Results. Overall, 145 patients (69%) were HCV coinfected, with a lower nadir (165 versus 220 cells/μL, respectively; p = 0.03) and baseline (374 versus 498 cells/μL, respectively; p = 0.04) CD4 count than monoinfected patients. Etravirine was mainly used with two nucleoside reverse transcriptase inhibitors (129; 61%) or with a boosted protease inhibitor (PI) (28%), with no significant differences according to HCV serostatus. Transient elastography in 117 patients (81%) showed a median (range) stiffness value of 8.25 (3.5–69) kPa, with fibrosis stage 1 in 43 patients (37%) and fibrosis stage 4 in 28 patients (24%). During an accumulated follow-up time of 449.3 patient-years (median 548 days), only one patient with advanced fibrosis (50.8 kPa) had grade 3–4 liver toxicity (0.7%). Transaminases changed slightly, with no significant differences compared with baseline fibrosis, and nine and six patients had grade 1 and 2 transaminase increases, respectively. Also, HCV coinfection was not associated with a higher risk of discontinuation (25% discontinued versus 21% of monoinfected patients; p = 0.39, log-rank test) or virological failure (8% versus 12%, respectively; p = 0.4). Conclusions. Our data suggest that etravirine is a safe option for HIV/HCV-coinfected patients, including those with significant liver fibrosis

Las decisiones de localización, alcance y escala de las empresas multinacionales españolas

This research has been partially funded by the Spanish Ministry of Economy and Competitiveness (project ECO2014-52051-R and ECO2017-82445-R) and by the Autonomous Region of Madrid through project S2015HUM-3417 (INNCOMCON-CM), co-funded by the European Social Fund (European Union). The authors benefited from presentations at the 4th PhD-Student Workshop on Industrial and Public Economics (Reus, 2016), the Conference on International Economics (La Coruña, 2016) and especially from suggestions from Andrés Barge.This paper examines the relationship between firms’ heterogeneity and their multinational activity. We examine the scope and the scale of multinational firms following the insights of Yeaple’s (2009) model. The goal of the paper is to contribute to a better understanding of the activity of Spanish multinationals using a sample of Spanish multinational firms. Our dataset is built from two databases, SABI and ORBIS, both from the Bureau van Dijk. Our results confirm that more productive firms have a greater multinational activity in terms of both the scope (the number of foreign markets where they invest) and the scale (the volume of local sales by subsidiaries in foreign markets). The structure of Spanish multinational firms’ activity is also analysed from the perspective of host country characteristics (GDP, population, distance and language) using standard gravity equations. Country characteristics that are positively associated (GDP and common language) with the volume of multinational activity are negatively related to the productivity of firms that go abroad. This asymmetry also holds for bilateral characteristics as distance that appears negatively associated with the level of multinational activity.En este trabajo se analiza la relación entre la heterogeneidad de las empresas españolas y su actividad multinacional contrastando las predicciones del modelo de Yeaple (2009). Se utiliza una base de datos de empresas multinacionales españolas fusionando dos bases de datos, SABI y ORBIS. Los resultados confirman que las empresas más productivas tienen una mayor actividad multinacional tanto en términos de alcance (número de mercados extranjeros donde las empresas matrices invierten) y de escala (el volumen de las ventas de las subsidiarias en los mercados extranjeros). La estructura de la actividad de las empresas multinacionales también se analiza desde la perspectiva de las características del país receptor (PIB, población, distancia, lengua común…) usando ecuaciones de gravedad. Las características del país que están positivamente relacionadas (PIB y lengua común…) con el volumen de la actividad multinacional presentan una relación negativa con la productividad de las empresas que operan en el exterior. Este efecto asimétrico también se produce para otras variables como la distancia que está negativamente asociada con la actividad multinacional y positivamente con la productividad de las empresas multinacionales.DecanatoFac. de Ciencias Económicas y EmpresarialesTRUEMinisterio de Economía y Competitividad (MINECO)Comunidad de Madridunpu

Robots Liability: A Use Case and a Potential Solution

In this chapter, a system of distribution of responsibility for damages caused by robots is introduced, and its practical application on the results obtained in the real experiences at the University of Almería (Spain) is analyzed. The attribution of liability for damages produced by autonomous agents usually focuses the theoretical discussion on legal and ethical fields on robotics. The European Parliament adopted the report with recommendations to the Commission on Civil Law Rules on Robotics (2015/2103(INL)) in February 2017. This work includes the master guidelines that the European Commission should take into account to legislate this technology. In its attempt to attribute responsibility for damages caused by robots, the Committee considers that once responsible parties have been identified, their liability level should range, looking the robot’s learning capability and the knowledge learned from its owner. This work proposes the use of responsibility setting matrix as a mechanism to distribute liabilities between the robot, the manufacturer, and the owner, depending on the knowledge programmed by the manufacturer and the one acquired by the robot (through its learning ability and the adjustments made by the owner), that would distribute the responsibility for damages among the three agents involved

Erosión minera en la cuenca del arroyo Peñalén (Parque Natural del Alto Tajo, Guadalajara)

Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEpu

Evolutionary site-number changes of ribosomal DNA loci during speciation: complex scenarios of ancestral and more recent polyploid events

Several genome duplications have been identified in the evolution of seed plants, providing unique systems for studying karyological processes promoting diversification and speciation. Knowledge about the number of ribosomal DNA (rDNA) loci, together with their chromosomal distribution and structure, provides clues about organismal and molecular evolution at various phylogenetic levels. In this work, we aim to elucidate the evolutionary dynamics of karyological and rDNA site-number variation in all known taxa of subtribe Vellinae, showing a complex scenario of ancestral and more recent polyploid events. Specifically, we aim to infer the ancestral chromosome numbers and patterns of chromosome number variation, assess patterns of variation of both 45S and 5S rDNA families, trends in site-number change of rDNA loci within homoploid and polyploid series, and reconstruct the evolutionary history of rDNA site number using a phylogenetic hypothesis as a framework. The best-fitting model of chromosome number evolution with a high likelihood score suggests that the Vellinae core showing x=17 chromosomes arose by duplication events froma recent x=8 ancestor. Our survey suggests more complex patterns of polyploid evolution than previously noted for Vellinae. High polyploidization events (6x, 8x) arose independently in the basal clade Vella castrilensis–V. lucentina, where extant diploid species are unknown. Reconstruction of ancestral rDNA states in Vellinae supports the inference that the ancestral number of loci in the subtribe was two for each multigene family, suggesting that an overall tendency towards a net loss of 5S rDNA loci occurred during the splitting of Vellinae ancestors from the remaining Brassiceae lineages. A contrasting pattern for rDNA site change in both paleopolyploid and neopolyploid species was linked to diversification of Vellinae lineages. This suggests dynamic and independent changes in rDNA site number during speciation processes and a significant lack of correlation between 45S and 5S rDNA evolutionary pathwaysThis research was supported by funds from the Spanish Ministry of Education and Science (Project CGL2010-22347-C02-01), the Catalan Government (Consolidated Research Group 2009SGR608) and by a Ph.D. grant from the Spanish Ministry of Education and Science to J.A.G