Determinación de los parámetros de productividad en los procesos de carenamiento en un varadero mediano

Productivity parameters were determined in maintenance works of 16 ships in the slipways of ASTINAVE, a medium-size shipyard at Guayaquil, Ecuador, in the period between April 2008 and January 2009. Typical processes applied during ship maintenance, its units for evaluation and a classification chart are presented. With the registered time (Man-Hour, M-H), mean values, standard deviations and variation coefficients were calculated for each process. Mean value results for each work were: Plating replacement: 0.220 M-H/kg, Hull cleaning: 0.435 M-H/m2-machine, Painting: 0.027 M-H/m2-machine, Cathodic protection: 0.116 M-H/Kg, Thickness measurement: 0.030 M-H/test, Propulsion system: 130.92 M-H/line, Steering system: 54.89 M-H/line, Ship docking/undocking: 43.97 M-H/maneuver, Bottom Valves: 15.83 M-H/#valve, and, Fuel tank cleaning: 0.0093 M-H/gal.Se determinaron Parámetros de Productividad en los trabajos de mantenimiento de 16 embarcaciones en el varadero de ASTINAVE, en Guayaquil, Ecuador, en el periodo Abril 08 hasta Enero 2009. Se describen, definen las unidades para su evaluación y se clasifican los procesos típicos que se desarrollan para el mantenimiento de buques. Con los tiempos (hombres-hora) registrados se calcularon los valores medios, desviaciones estándar y Coeficiente de Variación de los parámetros de cada proceso. Los valores medios resultantes son: Cambio de planchaje 0.220 H-H/kg, Limpieza del Casco 0.435 H-H/m2-máq, Pintado 0.027 H-H/m2-máq, Protección catódica 0.116 H-H/Kg, Medición de espesores 0.030 H-H/prueba, Sistema de Propulsión 130.92 H-H/línea, Sistema de Gobierno 54.89 H-H/línea, Varada/Desvarada 43.97 H-H/maniobra, Válvulas de Fondo 15.83 H-H/#válv, y, Tanques de combustible 0.0093 H-H/gal

Simulation of the wave evolution and power capture of an oscillating wave surge converter

For oscillating wave surge converters (OWSC) the incident wave field is changed due to the movement of the flap structure. A key component influencing this motion response is the Power Take-Off (PTO) system used. This paper examines the relationship between incident waves and the perturbed fluid field near the flap using the Computational Fluid Dynamics method by using Reynolds Averaged Navier-Stokes (RANS) equations. Further, it investigates the influence of a PTO system in the energy extracted from regular waves. Whilst this wave evolution is not significant in the effective power captured by a unit device, it is of great importance when performing in arrays as neighbouring devices may influence each other

Alternative mechanisms of p53 action during the unfolded protein response

The tumor suppressor protein p53 orchestrates cellular responses to a vast number of stresses, with DNA damage and oncogenic activation being some of the best described. The capacity of p53 to control cellular events such as cell cycle progression, DNA repair, and apoptosis, to mention some, has been mostly linked to its role as a transcription factor. However, how p53 integrates different signaling cascades to promote a particular pathway remains an open question. One way to broaden its capacity to respond to different stimuli is by the expression of isoforms that can modulate the activities of the full-length protein. One of these isoforms is p47 (p53/47, Δ40p53, p53ΔN40), an alternative translation initiation variant whose expression is specifically induced by the PERK kinase during the Unfolded Protein Response (UPR) following Endoplasmic Reticulum stress. Despite the increasing knowledge on the p53 pathway, its activity when the translation machinery is globally suppressed during the UPR remains poorly understood. Here, we focus on the expression of p47 and we propose that the alternative initiation of p53 mRNA translation offers a unique condition-dependent mechanism to differentiate p53 activity to control cell homeostasis during the UPR. We also discuss how the manipulation of these processes may influence cancer cell physiology in light of therapeutic approaches

Extracting Hα\alpha flux from photometric data in the J-PLUS survey

We present the main steps that will be taken to extract H$\alpha$ emission flux from Javalambre Photometric Local Universe Survey (J-PLUS) photometric data. For galaxies with $z\lesssim0.015$, the H$\alpha$+[NII] emission is covered by the J-PLUS narrow-band filter $F660$. We explore three different methods to extract the H$\alpha$ + [NII] flux from J-PLUS photometric data: a combination of a broad-band and a narrow-band filter ($r'$ and $F660$), two broad-band and a narrow-band one ($r'$, $i'$ and $F660$), and a SED-fitting based method using 8 photometric points. To test these methodologies, we simulated J-PLUS data from a sample of 7511 SDSS spectra with measured H$\alpha$ flux. Based on the same sample, we derive two empirical relations to correct the derived H$\alpha$+[NII] flux from dust extinction and [NII] contamination. We find that the only unbiased method is the SED fitting based one. The combination of two filters underestimates the measurements of the H$\alpha$ + [NII] flux by a 28%, while the three filters method by a 9%. We study the error budget of the SED-fitting based method and find that, in addition to the photometric error, our measurements have a systematic uncertainty of a 4.3%. Several sources contribute to this uncertainty: differences between our measurement procedure and the one used to derive the spectroscopic values, the use of simple stellar populations as templates, and the intrinsic errors of the spectra, which were not taken into account. Apart from that, the empirical corrections for dust extinction and [NII] contamination add an extra uncertainty of 14%. Given the J-PLUS photometric system, the best methodology to extract H$\alpha$ + [NII] flux is the SED-fitting based one. Using this method, we are able to recover reliable H$\alpha$ fluxes for thousands of nearby galaxies in a robust and homogeneous way.Comment: 11 pages, 14 figures. Minor changes to match the published versio

Influence of Modularity and Regularity on Disparity of Atelostomata Sea Urchins

A modularity approach is used to study disparity rates and evolvability of sea urchins belonging to the Atelostomata superorder. For this purpose, the pentameric sea urchin architecture is partitioned into modular spatial components and the interference between modules is quantified using areas and a measurement of the regularity of the spatial partitions. This information is used to account for the variability through time (disparity) and potential for morphological variation and evolution (evolvability) in holasteroid echinoids. We obtain that regular partitions of the space produce modules with high modular integrity, whereas irregular partitions produce low modular integrity; the former ones are related with high morphological disparity (facilitation hypothesis). Our analysis also suggests that a pentameric body plan with low regularity rates in Atelostomata reflects a stronger modular integration among modules than within modules, which could favors bilaterality against radial symmetry. Our approach constitutes a theoretical platform to define and quantify spatial organization in partitions of the space that can be related to modules in a morphological analysis

Magnetic field driving custom assembly in (FeCo) nanocrystals

We present the possibility of tuning the nanocrystalline microstructure of Co-rich samples by magnetic field annealing. Custom assembly of nucleated grains, aligned in the field direction, has been observed by means of high resolution transmission microscopy. The organized microstructure was obtained on the basis of the appropriate choice of composition, annealing temperature, related to the initial stages of nanocrystallization process, and magnetic field intensity. The linear pattern of the grains has been explained as a consequence of the counterbalance between magnetic, magnetostatic, and magnetocrystalline couplings, only relevant when the nucleation temperature is well below the Curie temperature of the nucleated phase

Field analysis of the deterioration after some years of use of four insect-proof screens utilized in Mediterranean greenhouses

The installation of insect-proof screens on greenhouse vents is one of the principal methods of protection against harmful insects for crops. Their main disadvantage lies on their negative effects on natural ventilation and greenhouse microclimate, which have been the focus of studies by several authors. However, few works have analysed the effect of accumulated dust and dirt on these screens. The present study has analysed four anti-insect screens, comparing their geometric characteristics before installation and after three to four years of use. Two negative effects have been observed and quantified: deterioration of the threads that make up the screen and reduction of porosity due to accumulated dirt in the pores. This deterioration over time gives leads to a mean increase in thread diameter of 3.1%, as well to a mean decrease in the pore size of 6.2% and 2.3% in the weft (Lpx) and the warp (Lpy), respectively. In fact, the insect-proof screen porosity (φ) decreased due to the deterioration of the threads by an average of 6.5%, in addition to an average 20.3% reduction due to the accumulation of dirt in the pores, making a total reduction in porosity of 26.8%. This decrease in porosity leads to lower greenhouse ventilation rates, and is therefore detrimental for the greenhouse microclimate. Consequently, it is recommended that insect-proof screens in arid areas such as Almería (Spain), with abundant dust suspended in the atmosphere, be washed monthly using water sprayed at high pressure

Delay time of waves performing Levy walks in 1D random media

[EN] The time that waves spend inside 1D random media with the possibility of performing Lévy walks is experimentally and theoretically studied. The dynamics of quantum and classical wave diffusion has been investigated in canonical disordered systems via the delay time. We show that a wide class of disorder¿Lévy disorder¿leads to strong random fluctuations of the delay time; nevertheless, some statistical properties such as the tail of the distribution and the average of the delay time are insensitive to Lévy walks. Our results reveal a universal character of wave propagation that goes beyond standard Brownian wave-diffusion.A. A. F.-M. thanks the hospitality of the Laboratoire d'Acoustique de l'Universite du Mans, France, where part of this work was done. J. A. M.-B, gratefully acknowledges to Departamento de Matematica Aplicada e Estatistica, Instituto de Ciencias Matematicas e de Computacao, Universidade de Sao Paulo during which this work was completed. J.A.M.-B. was supported by FAPESP (Grant No. 2019/06931-2), Brazil. A. A. F.-M. thanks partial support by RFI Le Mans Acoustique and by the project HYPERMETA funded under the program Etoiles Montantes of the Region Pays de la Loire. V. A. G. acknowledges support by MCIU (Spain) under the Project number PGC2018-094684-B-C22.Razo-López, LA.; Fernández-Marín, AA.; Mendez-Bermudez, JA.; Sánchez-Dehesa Moreno-Cid, J.; Gopar, VA. (2020). Delay time of waves performing Levy walks in 1D random media. Scientific Reports. 10(1):1-8. https://doi.org/10.1038/s41598-020-77861-xS18101Wigner, E. P. Lower limit for the energy derivative of the scattering phase shift. Phys. Rev. 147, 145–147 (1955).Smith, F. T. Lifetime matrix in collision theory. Phys. Rev. 119, 2098–2098 (1960).Fercher, A. F., Drexler, W., Hitzenberger, C. K. & Lasser, T. Optical coherence tomography -principles and applications. Rep. Prog. Phys. 66, 239–303 (2003).Lubatsch, A. & Frank, R. Self-consistent quantum field theory for the characterization of complex random media by short laser pulses. Phys. Rev. Res. 2, 013324 (2020).Anderson, P. W. Absence of diffusion in certain random lattices. Phys. Rev. 109, 1492–1505 (1958).Lagendijk, A., van Tiggelen, B. & Wiersma, D. S. Fifty years of Anderson localization. Phys. Today 62, 24–29 (2009).Genack, A. Z., Sebbah, P., Stoytchev, M. & van Tiggelen, B. A. Statistics of wave dynamics in random media. Phys. Rev. Lett. 82, 715–718 (1999).Sebbah, P., Legrand, O. & Genack, A. Z. Fluctuations in photon local delay time and their relation to phase spectra in random media. Phys. Rev. E 59, 2406–2411 (1999).Chabanov, A. A. & Genack, A. Z. Statistics of dynamics of localized waves. Phys. Rev. Lett. 87, 233903 (2001).Texier, C. Wigner time delay and related concepts: Application to transport in coherent conductors. Phys. E Low. Dimens. Syst. Nano Struct. 82, 16–33 (2016).Texier, C. & Comtet, A. Universality of the Wigner time delay distribution for one-dimensional random potentials. Phys. Rev. Lett. 82, 4220–4223 (1999).Schomerus, H., van Bemmel, K. J. H. & Beenakker, C. W. J. Coherent backscattering effect on wave dynamics in a random medium. EPL 52, 518–524 (2000).Xu, F. & Wang, J. Statistics of Wigner delay time in Anderson disordered systems. Phys. Rev. B 84, 024205 (2011).Ossipov, A. Scattering approach to Anderson localization. Phys. Rev. Lett. 121, 076601 (2018).Pierrat, R. et al. Invariance property of wave scattering through disordered media. Proc. Natl Acad. Sci. USA 111, 17765–17770 (2014).Blanco, S. & Fournier, R. An invariance property of diffusive random walks. EPL 61, 168–173 (2003).Savo, R. et al. Observation of mean path length invariance in light-scattering media. Science 358, 765–768 (2017).Falceto, F. & Gopar, V. A. Conductance through quantum wires with Lévy-type disorder: Universal statistics in anomalous quantum transport. EPL 92, 57014 (2010).Amanatidis, I., Kleftogiannis, I., Falceto, F. & Gopar, V. A. Conductance of one-dimensional quantum wires with anomalous electron wave-function localization. Phys. Rev. B 85, 235450 (2012).Kleftogiannis, I., Amanatidis, I. & Gopar, V. A. Conductance through disordered graphene nanoribbons: Standard and anomalous electron localization. Phys. Rev. B 88, 205414 (2013).Lima, J. R. F., Pereira, L. F. C. & Barbosa, A. L. R. Dirac wave transmission in Lévy-disordered systems. Phys. Rev. E 99, 032118 (2019).Mantegna, R. N. & Stanley, H. E. Scaling behaviour in the dynamics of an economic index. Nature 376, 46–49 (1995).Reynolds, A. M. & Ouellette, N. T. Swarm dynamics may give rise to Lévy flights. Sci. Rep. 6, 30515 (2016).Patel, R. & Mehta, R. V. Lévy distribution of time delay in emission of resonantly trapped light in ferrodispersions. J. Nanophoton. 6, 069503 (2012).Bouchaud, J.-P. & Georges, A. Anomalous diffusion in disordered media: statistical mechanisms, models and physical applications. Phys. Rep. 195, 127 (1990).Shlesinger, M. F., Klafter, J. & Zumofen, G. Above, below and beyond brownian motion. Am. J. Phys. 67, 1253–1259 (1999).Barkai, E., Fleurov, V. & Klafter, J. One-dimensional stochastic Lévy-Lorentz gas. Phys. Rev. E 61, 1164–1169 (2000).Barthelemy, P., Bertolotti, J. & Wiersma, D. A Lévy flight for light. Nature 453, 495–498 (2008).Solomon, T. H., Weeks, E. R. & Swinney, H. L. Observation of anomalous diffusion and Lévy flights in a two-dimensional rotating flow. Phys. Rev. Lett. 71, 3975–3978 (1993).Mercadier, N., Guerin, W., Chevrollier, M. & Kaiser, R. Lévy flights of photons in hot atomic vapours. Nat. Phys. 5, 602–605 (2009).Rocha, E. G. et al. Léy flights for light in ordered lasers. Phys. Rev. A 101, 023820 (2020).Zaburdaev, V., Denisov, S. & Klafter, J. Lévy walks. Rev. Mod. Phys. 87, 483–530 (2015).Uchaikin, V. V. & Zolotarev, V. M. Chance and Stability. Stable Distributions and Their Applications. (VSP, Utrecht, 1999).Garrett, C. & McCumber, D. Propagation of a Gaussian light pulse through an anomalous dispersion medium. Phys. Rev. A 1, 305–313 (1970).Dalitz, R. H. & Moorhouse, R. G. What is a resonance?. Proc. R. Soc. Lond. Ser. A 318, 279 (1970).Chu, S. & Wong, S. Linear pulse propagation in an absorbing medium. Phys. Rev. Lett. 48, 738–741 (1982).Durand, M., Popoff, S. M., Carminati, R. & Goetschy, A. Optimizing light storage in scattering media with the dwell-time operator. Phys. Rev. Lett. 123, 243901 (2019).Anderson, P. W., Thouless, D. J., Abrahams, E. & Fisher, D. S. New method for a scaling theory of localization. Phys. Rev. B 22, 3519–3526 (1980).Mello, P. & Kumar, N. Quantum Transport in Mesoscopic Systems: Complexity and Statistical Fluctuation (Oxford University Press, Oxford, 2004).Mello, P. A. Central-limit theorems on groups. J. Math. Phys. 27, 2876–2891 (1986).Jayannavar, A. M., Vijayagovindan, G. V. & Kumar, N. Energy dispersive backscattering of electrons from surface resonances of a disordered medium and 1/f noise. Z. Phys. B Condens. Matter 75, 77–79 (1989).Heinrichs, J. Invariant embedding treatment of phase randomisation and electrical noise at disordered surfaces. J. Phys. Condens. Matter 2, 1559–1568 (1990).Comtet, A. & Texier, C. On the distribution of the Wigner time delay in one-dimensional disordered systems. J. Phys. A: Math. Gen. 30, 8017–8025 (1997).Bolton-Heaton, C. J., Lambert, C. J., Falḱo, V. I., Prigodin, V. & Epstein, A. J. Distribution of time constants for tunneling through a one-dimensional disordered chain. Phys. Rev. B 60, 10569–10572 (1999).Beenakker, C. W. J. Dynamics of Localization in a Waveguide, 489–508 (Springer, Netherlands, 2001).Klyatskin, V. I. & Saichev, A. I. Statistical and dynamic localization of plane waves in randomly layered media. Sov. Phys. Uspekhi 35, 231–247 (1992).Anantha Ramakrishna, S. & Kumar, N. Imaginary potential as a counter of delay time for wave reflection from a one-dimensional random potential. Phys. Rev. B 61, 3163–3165 (2000).Beenakker, C. W. J., Paasschens, J. C. J. & Brouwer, P. W. Probability of reflection by a random laser. Phys. Rev. Lett. 76, 1368–1371 (1996).Kottos, T. Statistics of resonances and delay times in random media: beyond random matrix theory. J. Phys. A: Math. Gen. 38, 10761–10786 (2005).Calvo, I., Cuchí, J. C., Esteve, J. G. & Falceto, F. Generalized central limit theorem and renormalization group. J. Stat. Phys. 141, 409 (2010)

MODASC: ASIC for mobile data acquisition systems using satellite communications

MODASC is an ASIC that performs wide area mobile data acquisition using satellite communication to provide global coverage. This circuit provides two operation modes: an autonomous mode, that periodically establishes connection with the control center, and a slave mode, working as a peripheral connected to a general purpose micro controller. This experiment has been realized under FUSE special action in collaboration with SAINSEL

Reasons for abandoning early exclusive breastfeeding: an unsolved public health problem in Medellín

ABSTRACT: To identify the reasons for the early abandonment of exclusive breastfeeding in the city of Medellin in 2011. Methodology: a descriptive study with a 95% confidence interval and a sample of 303 mothers with children under 24 months. These participants were enrolled in one of the social programs of the municipality of Medellin and had abandoned exclusive breastfeeding before the children were six months old. A structured survey was used to collect information regarding the mothers, their children, and the reasons for abandoning early breastfeeding. Frequencies and percentages were described and an assessment was performed to see if motives and age were associated with the abandonment of exclusive breastfeeding. Results: early abandonment occurred mainly before the child was four months old. The main reasons were related to milk production problems, baby rejection, the mother’s activities or occupations, and her health status. Additionally, the participants reported the use of infant formulas as substitutes or supplements to breast milk. Conclusions: the reasons for early abandonment of breastfeeding have changed; this is why mothers must have the knowledge needed to increase breast milk production, the assistance of qualified personnel, and the working conditions allowing them to attend to these needs.RESUMEN: Identificar los motivos del abandono temprano de la lactancia materna exclusiva en la ciudad de Medellín en el año 2011. Metodología: se realizó un estudio descriptivo transversal con una confianza del 95% para una muestra de 303 madres con hijos menores de 24 meses, inscritos en uno de los programas sociales de la alcaldía de Medellín que habían abandonado la lactancia materna exclusiva antes de los seis meses. Se aplicó una encuesta estructurada sobre las madres, sus hijos, los motivos para el abandono temprano y los alimentos introducidos. Se describieron frecuencias y evaluaron asociaciones con los motivos y edad de abandono de la lactancia materna exclusiva. Resultados: el abandono temprano ocurrió principalmente antes de los cuatro meses de edad del niño(a). Los principales motivos estuvieron relacionados con problemas para la producción láctea, rechazo del bebé, actividades u ocupaciones de la madre y el estado de salud. Los alimentos reportados como reemplazo o complementarios a la leche materna, fueron principalmente fórmulas infantiles. Conclusiones: los motivos de abandono temprano han cambiado, porque ahora es clave que la madre tenga el conocimiento necesario para aumentar la producción de leche materna, la orientación por parte de personal entrenado y que le brinden a esta las condiciones laborales que se lo permitan