Comparison of splice sites in mammals and chicken

We have carried out an initial analysis of the dynamics of the recent evolution of the splice-sites sequences on a large collection of human, rodent (mouse and rat), and chicken introns. Our results indicate that the sequences of splice sites are largely homogeneous within tetrapoda. We have also found that orthologous splice signals between human and rodents and within rodents are more conserved than unrelated splice sites, but the additional conservation can be explained mostly by background intron conservation. In contrast, additional conservation over background is detectable in orthologous mammalian and chicken splice sites. Our results also indicate that the U2 and U12 intron classes seem to have evolved independently since the split of mammals and birds; we have not been able to find a convincing case of interconversion between these two classes in our collections of orthologous introns. Similarly, we have not found a single case of switching between AT-AC and GT-AG subtypes within U12 introns, suggesting that this event has been a rare occurrence in recent evolutionary times. Switching between GT-AG and the noncanonical GC-AG U2 subtypes, on the contrary, does not appear to be unusual; in particular, T to C mutations appear to be relatively well tolerated in GT-AG introns with very strong donor sites.

Linguistic and maternal genetic diversity are not correlated in native mexicans

Mesoamerica, defined as the broad linguistic and cultural area from middle southern Mexico to Costa Rica, might have played a pivotal role during the colonization of theAmerican continent. It has been suggested that the Mesoamerican isthmus could have played an important role in severely restricting prehistorically gene flow between North and SouthAmerica. Although the Native American component has been already described in admixedMexican populations, few studies have been carried out in native Mexican populations. In thisstudy we present mitochondrial DNA (mtDNA) sequence data for the first hypervariable region (HVR-I) in 477 unrelated individuals belonging to eleven different native populations from Mexico. Almost all the Native Mexican mtDNAs could be classified into the four pan-Amerindian haplogroups (A2, B2, C1 and D1); only three of them could be allocated to the rare Native American lineage D4h3. Their haplogroup phylogenies are clearly star-like, as expected from relatively young populations that have experienced diverse episodes of genetic drift (e.g. extensive isolation, genetic drift and founder effects) and posterior population expansions. In agreement with this observation is the fact that Native Mexican populations show a high degree of heterogeneity in their patterns of haplogroup frequencies. HaplogroupX2a was absent in our samples, supporting previous observations where this clade was only detected in the American northernmost areas. The search for identical sequences in the American continent shows that, although Native Mexican populations seem to show a closer relationship to North American populations, they cannot be related to a single geographical region within the continent. Finally, we did not find significant population structure on the maternal lineages when considering the four main and distinct linguistic groups represented in our Mexican samples (Oto-Manguean, Uto-Aztecan, Tarascan, and Mayan), suggesting that genetic divergence predates linguistic diversification in Mexico.

La duración consonántica en castellano

This paper presents the results of an experimental analysis of the duralion of Spanish consonants. The influence of three different factors—stress, location on thesyllable, and pause vicinity— on the duration of consonants in reading text has been studied. Phonetic context and speech rate have also been controlled. The obtained results seem to indicate that the vicinity of a pause and the location of the consonant in the syllable have a systematic effect on all the consonants, while the stress only affects the duration of a rcduced set of voicedallophones ([1], [r] and [n]). Some general conclusions about the mean duration of each consonant, and about the relationship between duration and voicing, manner and place of articulation, have also been established.

Unstable equilibrium: young adult women in family and career formation in Southern Europe

The paper examines the relationship between family formation (i.e., living with a partner and having children) and women’s occupational career in southern Europe (i.e., Greece, Italy, Portugal and Spain). The relationship is explored by analysing the impact that different family structures and male [nvolvement in caring activities have on women’s early occupational trajectories (i.e., remaining in the same occupational status, experiencing downward or upward mobility, or withdrawing from paid work). This research shows that male involvement in caring activities does not really push women ahead in their career, but the absolute lack of male support seems to negatively affect women’s permanence in paid work. These results apply to all southern European countries except Portugal, where the absolute absence of the partners’ support in caring activities does not seem to alter women’s determination to remain in paid work. The methodology applied consists of the estimation of multinomial logit regression models and the analysis is based on eight waves (1994-2001) of the European Community Household Panel (ECHP).

The Effect of occupational sex-composition on earnings: job-specialisation, sex-role attitudes and the division of domestic-labour in Spain

Important theoretical controversies remain unresolved in the literatire on occupational sex-segregation and the gender wage-gap. A useful way of summarising these controversies is viewing them as a debate between - cultural -socialisation. The paper discusses these theories in detail and carries out a preliminary test of the relative explanatory performance of some of their most consequential predictions. This is done by drawing on the Spanish sample of the second wave of the European Social Survey, ESS. The empirical analysis of ESS data illustrates the notable analytical pay-offs that can stem from using rich individual-level indicators, but also exemplifies the statistical llimitations generated by small sample size and high rates of non-response. Empirical results should, therefore, be taken as preliminary. They seem to suggest that the effect of occupational sex-segregation on wages could be explicable by workers' sex-role attitutes, their relative input in domestic production and the job-specific human capital requirements of their jobs. Of these three factors, job-specialisation seeems clearly the most important one.

Temporary employment in advanced economies: drawing lessons from Spain

This study analyses the determinants of the rate of temporary employment in various OECD countries using both macro-level data drawn from the OECD and EUROSTAT databases, as well as micro-level data drawn from the 8th wave of the European Household Panel. Comparative analysis is set out to test different explanations originally formulated for the Spanish case. The evidence suggests that the overall distribution of temporary employment in advanced economies does not seem to be explicable by the characteristics of national productive structures. This evidence seems at odds with previous interpretations based on segmentation theories. As an alternative explanation, two types of supply-side factors are tested: crowding-out effects and educational gaps in the workforce. The former seems non significant, whilst the effects of the latter disappear after controlling for the levels of institutional protection in standard employment during the 1980s. Multivariate analysis shows that only this latter institutional variable, together with the degree of coordinated centralisation of the collective bargaining system, seem to have a significant impact on the distribution of temporary employment in the countries examined. On the basis of this observation, an explanation of the very high levels of temporary employment observed in Spain is proposed. This explanation is consistent with both country-specific and comparative evidence.

Spotting Translationese in two Corpora of Original and Translated Catalan Texts: an Empirical Approach

This research investigates the phenomenon of translationese in two monolingual comparable corpora of original and translated Catalan texts. Translationese has been defined as the dialect, sub-language or code of translated language. This study aims at giving empirical evidence of translation universals regardless the source language.Traditionally, research conducted on translation strategies has been mainly intuition-based. Computational Linguistics and Natural Language Processing techniques provide reliable information of lexical frequencies, morphological and syntactical distribution in corpora. Therefore, they have been applied to observe which translation strategies occur in these corpora.Results seem to prove the simplification, interference and explicitation hypotheses, whereas no sign of normalization has been detected with the methodology used.The data collected and the resources created for identifying lexical, morphological and syntactic patterns of translations can be useful for Translation Studies teachers, scholars and students: teachers will have more tools to help students avoid the reproduction of translationese patterns. Resources developed will help in detecting non-genuine or inadequate structures in the target language. This fact may imply an improvement in stylistic quality in translations. Translation professionals can also take advantage of these resources to improve their translation quality.

The varieties of regional change

Many metropolitan areas have experienced extreme boom-bust cycles over the past century. Some places, like Detroit, grew enormously as industrial powerhouses and then declined, while other older cities, like Boston, seem quite resilient. Education does a reasonable job of explaining urban resilience. In this paper, we present a simple model where education increases the level of entrepreneurship. In this model, human capital spillovers occur at the city level because skilled workers produce more product varieties and thereby increase labor demand. We decompose empirically the causes of the connection between skills and urban success and find that skills are associated with growth in productivity or entrepreneurship, not with growth in quality of life, at least outside of the West. We also find that skills seem to have depressed housing supply growth in the West, but not in other regions, which supports the view that educated residents in that region have fought for tougher land-use controls. We also present evidence that skills have had a disproportionately large impact on unemployment during the current recession.

Compositions in life science data

The aim of this talk is to convince the reader that there are a lot of interesting statisticalproblems in presentday life science data analysis which seem ultimately connected withcompositional statistics.Key words: SAGE, cDNA microarrays, (1D-)NMR, virus quasispecies

Country portfolios and the Solow-model

This paper shows that an open economy Solow model provides a good description of international investment positions in industrialized countries. More than half of the variation of net foreign assets in the 1990's can be attributed to cross country differences in the savings rate, population and productivity growth. Furthermore, these factors seem to be an important channel through which output and wealth affect international investment positions. We interpret this funding as evidence that decreasing returns are an important source of international capital movements. The savings rate (andpopulation growth) influence the composition of country portfolios through their downward (upward) pressure on the marginal productivity of capital.

The value of useless information

There are many situations in which individuals have a choice of whether or notto observe eventual outcomes. In these instances, individuals often prefer to remainignorant. These contexts are outside the scope of analysis of the standard vonNeumann-Morgenstern (vNM) expected utility model, which does not distinguishbetween lotteries for which the agent sees the final outcome and those for which hedoes not. I develop a simple model that admits preferences for making an observationor for remaining in doubt. I then use this model to analyze the connectionbetween preferences of this nature and risk-attitude. This framework accommodatesa wide array of behavioral patterns that violate the vNM model, and thatmay not seem related, prima facie. For instance, it admits self-handicapping, inwhich an agent chooses to impair his own performance. It also accommodatesa status quo bias without having recourse to framing effects, or to an explicitdefinition of reference points. In a political economy context, voters have strictincentives to shield themselves from information. In settings with other-regardingpreferences, this model predicts observed behavior that seems inconsistent witheither altruism or self-interested behavior.

How important is the intensive margin of labor adjustment?

Using new quarterly data for hours worked in OECD countries, Ohanian and Raffo (2011) argue that in many OECD countries, particularly in Europe, hours per worker are quantitatively important as an intensive margin of labor adjustment, possibly because labor market frictions are higher than in the US. I argue that this conclusion is not supported by the data. Using the same data on hours worked, I find evidence that labor market frictions are higher in Europe than in the US, like Ohanian and Raffo, but also that these frictions seem to affect the intensive margin at least as much as the extensive margin of labor adjustment.

Cashing by the hour: Why large law firms prefer hourly fees over contingent fees

Large law firms seem to prefer hourly fees over contingent fees. Thispaper provides a moral hazard explanation for this pattern of behavior.Contingent legal fees align the interests of the attorney with those ofthe client, but not necessarily with those of the partnership. We showthat the choice of hourly fees is a solution to an agency problem withmultiple principals, where the interests of one principal (law firm)collide with the interests of the other principal (client).

Endogenous credit cycles

I develop an overlapping-generations framework in which changes in lending standards generateendogenous cycles. In my economy, entrepreneurs who are privately informed about thequality of their projects need to borrow funds. Intermediaries screen entrepreneurs both throughthe amount of investment undertaken and through the level of entrepreneurial net worth.I show that endogenous regime switches in financial contracts from pooling to separatingand vice-versa may generate fluctuations even in the absence of exogenous shocks. Whenthe economy is in the pooling (separating) regime, lending standards seem lax ( tight ) andinvestment is high (low). Differently from the existing literature, my model does not requireentrepreneurial net worth to be counter cyclycal or inconsequential for determining aggregateinvestment.

Supply chain management implementation in the Spanish grocery sector: An exploratory study

This paper explores the integration process that firms follow to implementSupply Chain Management (SCM) and the main barriers and benefits relatedto this strategy. This study has been inspired in the SCM literature,especially in the logistics integration model by Stevens [1]. Due to theexploratory nature of this paper and the need to obtain an in depthknowledge of the SCM development in the Spanish grocery sector, we used thecase study methodology. A multiple case study analysis based on interviewswith leading manufacturers and retailers was conducted.The results of this analysis suggest that firms seem to follow the integration process proposed by Stevens, integrating internally first, andthen, extending this integration to other supply chain members. The casesalso show that Spanish manufacturers, in general, seem to have a higherlevel of SCM development than Spanish retailers. Regarding the benefitsthat SCM can bring, most of the companies identify the general objectivesof cost and stock reductions and service improvements. However, withrespect to the barriers found in its implementation, retailers andmanufacturers are not coincident: manufacturers seem to see more barrierswith respect to aspects related to the other party, such as distrust and alack of culture of sharing information, while retailers find as mainbarriers the need of a know-how , the company culture and the historyand habits.