Productivity Growth during the English Industrial Revolution: A Dual Approach

This paper presents new estimates of total factor productivity growth in Britain for the period 1770-1860. We use a dual technique recently popularized by Hsieh (1999), and argue that the estimates we derive from factor prices are of similar quality to quantity-based calculations. Our results provide further evidence, derived from this independent set of sources, that productivity growth during the British Industrial Revolution was relatively slow. During the years 1770-1800, TFP growth was close to zero, according to our estimates. The period 1800-1830 experienced an acceleration of productivity growth. The Crafts-Harley view of the Industrial Revolution is thus reinforced. We also consider alternative explanations of slow productivity growth, and reject the interpretation that focuses on the introduction of steam as a general purpose technology.

A burst of segmental duplications in the genome of the African great ape ancestor

It is generally accepted that the extent of phenotypic change between human and great apes is dissonant with the rate of molecular change. Between these two groups, proteins are virtually identical, cytogenetically there are few rearrangements that distinguish ape-human chromosomes, and rates of single-base-pair change and retrotransposon activity have slowed particularly within hominid lineages when compared to rodents or monkeys. Studies of gene family evolution indicate that gene loss and gain are enriched within the primate lineage. Here, we perform a systematic analysis of duplication content of four primate genomes (macaque, orang-utan, chimpanzee and human) in an effort to understand the pattern and rates of genomic duplication during hominid evolution. We find that the ancestral branch leading to human and African great apes shows the most significant increase in duplication activity both in terms of base pairs and in terms of events. This duplication acceleration within the ancestral species is significant when compared to lineage-specific rate estimates even after accounting for copy-number polymorphism and homoplasy. We discover striking examples of recurrent and independent gene-containing duplications within the gorilla and chimpanzee that are absent in the human lineage. Our results suggest that the evolutionary properties of copy-number mutation differ significantly from other forms of genetic mutation and, in contrast to the hominid slowdown of single-base-pair mutations, there has been a genomic burst of duplication activity at this period during human evolution.

Image restoration in astronomy: a Bayesian perspective

When preparing an article on image restoration in astronomy, it is obvious that some topics have to be dropped to keep the work at reasonable length. We have decided to concentrate on image and noise models and on the algorithms to find the restoration. Topics like parameter estimation and stopping rules are also commented on. We start by describing the Bayesian paradigm and then proceed to study the noise and blur models used by the astronomical community. Then the prior models used to restore astronomical images are examined. We describe the algorithms used to find the restoration for the most common combinations of degradation and image models. Then we comment on important issues such as acceleration of algorithms, stopping rules, and parameter estimation. We also comment on the huge amount of information available to, and made available by, the astronomical community.

Edelfosine-induced metabolic changes in cancer cells that precede the overproduction of reactive oxygen species and apoptosis

Background: Metabolic flux profiling based on the analysis of distribution of stable isotope tracer in metabolites is an important method widely used in cancer research to understand the regulation of cell metabolism and elaborate new therapeutic strategies. Recently, we developed software Isodyn, which extends the methodology of kinetic modeling to the analysis of isotopic isomer distribution for the evaluation of cellular metabolic flux profile under relevant conditions. This tool can be applied to reveal the metabolic effect of proapoptotic drug edelfosine in leukemia Jurkat cell line, uncovering the mechanisms of induction of apoptosis in cancer cells. Results: The study of 13C distribution of Jukat cells exposed to low edelfosine concentration, which induces apoptosis in ¿5% of cells, revealed metabolic changes previous to the development of apoptotic program. Specifically, it was found that low dose of edelfosine stimulates the TCA cycle. These metabolic perturbations were coupled with an increase of nucleic acid synthesis de novo, which indicates acceleration of biosynthetic and reparative processes. The further increase of the TCA cycle fluxes, when higher doses of drug applied, eventually enhance reactive oxygen species (ROS) production and trigger apoptotic program. Conclusion: The application of Isodyn to the analysis of mechanism of edelfosine-induced apoptosis revealed primary drug-induced metabolic changes, which are important for the subsequent initiation of apoptotic program. Initiation of such metabolic changes could be exploited in anticancer therapy.

Initial state of ultrarelativistic heavy ion collision

A model for energy, pressure, and flow velocity distributions at the beginning of ultrarelativistic heavy ion collisions is presented, which can be used as an initial condition for hydrodynamic calculations. Our model takes into account baryon recoil for both target and projectile, arising from the acceleration of partons in an effective field F mu nu produced in the collision. The typical field strength (string tension) for RHIC energies is about 512 GeV/fm, which allows us to talk about string ropes. The results show that a quark-gluon plasma forms a tilted disk, such that the direction of the largest pressure gradient stays in the reaction plane, but deviates from both the beam and the usual transverse flow directions. Such initial conditions may lead to the creation of antiflow or third flow component [L. P. Csernai and D. Rhrich, Phys. Rev. Lett. B 458, 454 (1999)].

Anomalous roughening of Hele-Shaw flows with quenched disorder

The kinetic roughening of a stable oil-air interface moving in a Hele-Shaw cell that contains a quenched columnar disorder (tracks) has been studied. A capillary effect is responsible for the dynamic evolution of the resulting rough interface, which exhibits anomalous scaling. The three independent exponents needed to characterize the anomalous scaling are determined experimentally. The anomalous scaling is explained in terms of the initial acceleration and subsequent deceleration of the interface tips in the tracks coupled by mass conservation. A phenomenological model that reproduces the measured global and local exponents is introduced.

Bubbles in Kaluza-Klein theories with spacelike or timelike internal dimensions

region to the other. We also present a C-type solution that describes neutral bubbles in uniform acceleration, and we use it to construct an instanton that mediates the breaking of a cosmic string by forming bubbles at its ends. The rate for this process is also calculated. Finally, we argue that a similar solution can be constructed for magnetic bubbles, and that it can be used to describe a semiclassical instability of the two-timing vacuum against production of massless monopole pairs.

Velocity fluctuations of fracturelike disruptions of associating polymer solutions

Velocity has been measured as a function of time for propagating crack tips as water is injected into solutions of end-capped associating polymers in a rectanguar Hele-Shaw cell. Measurements were performed for flows with different values of cell gap, channel width, polymer molecular weight, and polymer concentration. The condition for the onset of fracturelike behavior is well described by a Deborah number which uses the shear-thinning shear rate of the polymer solution as a characteristic frequency for network relaxation. At low molecular weight, the onset of fracturelike pattern evolution is accompanied by an abrupt jump in tip velocity, followed by a lower and approximately constant acceleration. At high molecular weight, the transition to fracturelike behavior involves passing through a regime that may be understood in terms of stick-slip dynamics. The crack-tip wanders from side to side and fluctuates (in both speed and velocity along the channel) with a characteristic frequency which depends linearly on the invading fluid injection rate.

Edelfosine-induced metabolic changes in cancer cells that precede the overproduction of reactive oxygen species and apoptosis

Background: Metabolic flux profiling based on the analysis of distribution of stable isotope tracer in metabolites is an important method widely used in cancer research to understand the regulation of cell metabolism and elaborate new therapeutic strategies. Recently, we developed software Isodyn, which extends the methodology of kinetic modeling to the analysis of isotopic isomer distribution for the evaluation of cellular metabolic flux profile under relevant conditions. This tool can be applied to reveal the metabolic effect of proapoptotic drug edelfosine in leukemia Jurkat cell line, uncovering the mechanisms of induction of apoptosis in cancer cells. Results: The study of 13C distribution of Jukat cells exposed to low edelfosine concentration, which induces apoptosis in ¿5% of cells, revealed metabolic changes previous to the development of apoptotic program. Specifically, it was found that low dose of edelfosine stimulates the TCA cycle. These metabolic perturbations were coupled with an increase of nucleic acid synthesis de novo, which indicates acceleration of biosynthetic and reparative processes. The further increase of the TCA cycle fluxes, when higher doses of drug applied, eventually enhance reactive oxygen species (ROS) production and trigger apoptotic program. Conclusion: The application of Isodyn to the analysis of mechanism of edelfosine-induced apoptosis revealed primary drug-induced metabolic changes, which are important for the subsequent initiation of apoptotic program. Initiation of such metabolic changes could be exploited in anticancer therapy.

Prosody and pragmatics in parenthetical insertions in catalan

This paper analyses the role of prosody in parenthetical insertions, a type of structure that is extremely common in both speech and writing. The materials under study come from a corpus of spontaneous speech acts in Central Catalan (with varying degrees of spontaneity) from which a corpus of oral parenthetical insertions has been compiled. The prototypical prosodic features of a parenthetical insertion in Catalan are: prosodic autonomy, limited extension, production in between pauses or final pause, tendency towards acceleration, fall in intensity, lower pitch range and, finally, falling or rising melodic pattern. While the final fall is the most frequent pattern in spontaneous conversations with a high degree of confidence between interlocutors, a final rising structure is found in interviews in which the degree of confidence between participants is smaller, their roles are unequal, and the interviewed constructs a narrative discourse. We thus suggest that the pitch contour of parenthetical insertions is related to formality and discourse typology (in this case, narrative vs. dialogue). Bearing in mind the discursive functions performed by these insertions, we propose a typology which classifies them with regards to two main functions: completion of information, and modalisation.

Vanishing Clams on an iberian beach: local consequences and global implication of accelerating loss of shells to tourism

Multi-decadal increase in shell removal by tourists, a process that may accelerate degradation of natural habitats, was quantified via two series of monthly surveys, conducted thirty years apart (1978-1981 and 2008-2010) in one small embayment on the Mediterranean coast of Spain. Over the last three decades, the local tourist arrivals have increased almost three-fold (2.74), while the area has remained unaffected by urban encroachment and commercial fisheries. Concomitantly, abundance of mollusk shells along the shoreline decreased almost three-fold (2.62) and displayed a tight inverse correlation with tourist arrivals. A four-fold increase in tourist arrivals observed globally over the last 30 years has likely induced a comparable worldwide acceleration in shell removal from marine shorelines and exerted multiple negative (but currently unquantifiable) habitat changes that may include increased beach erosion, changes in carbon and calcium cycles, and decline in diversity and abundance of organisms dependent on shell availability.

Entrenament d'un ciclista esprinter mitjançant la força explosiva: avaluació dels efectes d'un entrenament específic

La principal fita dels ciclistes ha estat sempre l’entrenament per millorar les seves condicions i prestacions fisiològiques. Al llarg dels anys, el ciclisme com pràcticament tot l’esport s’ha anat modernitzant, no només tecnològicament. Això ha provocat l’aparició d’especialistes, corredors destinats a destacar, només en unes determinades condicions, per sobre els demés. Una d’aquestes condicions més restringides son les arribades massives, terreny dels anomenats esprinters, els quals brillen per sobre els demés degut a la seva potència, velocitat punta i arrancada. L’entrenament d’aquesta tipologia d’especialitat ha deixat entreveure varies ambigüitats i algunes problemàtiques de fonament teòric. L’esprint en el ciclisme es dona després d’un gran desgast de les reserves energètiques i de fatiga muscular. Per tant, entrenar-lo amb blocs de velocitat no té lògica. Tampoc es una opció viable el recurs que molts equips utilitzen: agafar corredors joves de la pista, i que la seva genètica (fibres ràpides) i les seves característiques de pistard1 facin la resta, perquè al pas dels anys perden aquesta exclusivitat. Aquest estudi es proposa buscar una manera de treballar i potenciar l’esprint del ciclista a partir de la força explosiva, garantint preservar les condicions aeròbiques per tal de que no perjudiqui per altra banda la seva resistència. Per tal d’aconseguir-ho, s’efectuaran uns tests. Un focalitzat en mesurar les prestacions en un esprint dels subjectes. L’altra es basarà en avaluar la força explosiva d’aquets, a partir de salts verticals. Un cop obtinguts els resultats de la primera tanda, els subjectes seran sotmesos a un entrenament combinat de sobrecàrrega, per tal de observar, en la segona tanda, si els resultats son significatius. Com a conclusió, es podria destacar el fet de millora en la majoria d’aspectes en tots els tests per part de tots els subjectes, i que probablement, hi ha una correlació significativa entre la força explosiva i la capacitat per esprintar, tot i que s’haurien de corroborar els resultats amb una mostra més gran.

The number of planar central configurations for the 4-body problem is finite when 3 mass positions are fixed

In the n{body problem a central con guration is formed when the position vector of each particle with respect to the center of mass is a common scalar multiple of its acceleration vector. Lindstrom showed for n = 3 and for n > 4 that if n ? 1 masses are located at xed points in the plane, then there are only a nite number of ways to position the remaining nth mass in such a way that they de ne a central con guration. Lindstrom leaves open the case n = 4. In this paper we prove the case n = 4 using as variables the mutual distances between the particles.

Equilibrium points and central configurations for the Lennard-Jones 2-and 3-body problems

Abstract. In this paper we study the relative equilibria and their stability for a system of three point particles moving under the action of a Lennard{Jones potential. A central con guration is a special position of the particles where the position and acceleration vectors of each particle are proportional, and the constant of proportionality is the same for all particles. Since the Lennard{Jones potential depends only on the mutual distances among the particles, it is invariant under rotations. In a rotating frame the orbits coming from central con gurations become equilibrium points, the relative equilibria. Due to the form of the potential, the relative equilibria depend on the size of the system, that is, depend strongly of the momentum of inertia I. In this work we characterize the relative equilibria, we nd the bifurcation values of I for which the number of relative equilibria is changing, we also analyze the stability of the relative equilibria.

Sensorimotor Plasticity after Music-Supported Therapy in Chronic Stroke Patients Revealed by Transcranial Magnetic Stimulation

BACKGROUND: Several recently developed therapies targeting motor disabilities in stroke sufferers have shown to be more effective than standard neurorehabilitation approaches. In this context, several basic studies demonstrated that music training produces rapid neuroplastic changes in motor-related brain areas. Music-supported therapy has been recently developed as a new motor rehabilitation intervention. METHODS AND RESULTS: In order to explore the plasticity effects of music-supported therapy, this therapeutic intervention was applied to twenty chronic stroke patients. Before and after the music-supported therapy, transcranial magnetic stimulation was applied for the assessment of excitability changes in the motor cortex and a 3D movement analyzer was used for the assessment of motor performance parameters such as velocity, acceleration and smoothness in a set of diadochokinetic movement tasks. Our results suggest that the music-supported therapy produces changes in cortical plasticity leading the improvement of the subjects' motor performance. CONCLUSION: Our findings represent the first evidence of the neurophysiological changes induced by this therapy in chronic stroke patients, and their link with the amelioration of motor performance. Further studies are needed to confirm our observations.