Schooling supply and the structure of production: Evidence from US States 1950-1990

We find that over the period 1950-1990, US states absorbed increases in the supplyof schooling due to tighter compulsory schooling and child labor laws mostly throughwithin-industry increases in the schooling intensity of production. Shifts in the industrycomposition towards more schooling-intensive industries played a less important role.To try and understand this finding theoretically, we consider a free trade model withtwo goods/industries, two skill types, and many regions that produce a fixed rangeof differentiated varieties of the same goods. We find that a calibrated version ofthe model can account for shifts in schooling supply being mostly absorbed throughwithin-industry increases in the schooling intensity of production even if the elasticityof substitution between varieties is substantially higher than estimates in the literature.

Checklist of aedine mosquito species (Diptera, Culicidae, Aedini) occurring in Middle and South America (south of the United States) reflecting current generic and subgeneric status

A list of species of tribe Aedini from Middle and South American, south of the United States, with their current generic combinations is provided. Its purpose is to enable entomologists, public health personnel and mosquito control workers to more quickly become familiar with recent formal taxonomic changes within the tribe.

Technical inefficiency and public capital in US States: A stochastic frontier approach

This paper estimates a translog stochastic frontier production function in the analysis of all 48 contiguous U.S. states in the period 1970-1983, to attempt to measure and explain changes in technical efficiency. The model allows technical inefficiency to vary over time, and inefficiency effects to be a function of a set of explanatory variables in which the level and composition of public capital plays an important role. Results indicated that U.S. state inefficiency levels were significantly and positively correlated with the ratio of public capital to private capital. The proportion of public capital devoted to highways is negatively correlated with technical inefficiency, suggesting that not only the level but also the composition of public capital influenced state efficiency.

It's still 2%: evidence on convergence from 116 years of the US States panel data

A new debate over the speed of convergence in per capita income across economies is going on. Cross sectional estimates support the idea of slow convergence of about two percent per year. Panel data estimates support the idea of fast convergence of five, ten or even twenty percent per year. This paper shows that, if you ``do it right'', even the panel data estimation method yields the result of slow convergence of about two percent per year.

Description of Micropygomyia (Sauromyia) vonatzingeni sp. nov. (Diptera, Psychodidae, Phlebotominae) from the states of Pará and Tocantins, Brazil

Both sexes of a new phlebotomine sandfly species Micropygomyia (Sauromyia) vonatzingeni sp. nov. (Diptera, Psychodidae), captured in the Serra das Andorinhas, São Geraldo do Araguaia municipality, Pará state, and Cavalcante municipality, Tocantins state, Brazil, are described and illustrated. This new species belongs to the oswaldoi series and its distinction from the other extant species of the series was made by male and female identification keys. The specific geographical distribution of the oswaldoi series by country and department (or state) is presented.

How political parties, rather than member-states, are building the European Union

Political party formation and coalition building in the European Parliament is being a driving force for making governance of the highly pluralistic European Union relatively effective and consensual. In spite of successive enlargements and the very high number of electoral partiesobtaining representation in the European Union institutions, the number of effective European Political Groups in the European Parliament has decreased from the first direct election in 1979 to the fifth in 1999. The formal analysis of national party¹s voting power in different Europeanparty configurations can explain the incentives for national parties to join large European Political Groups instead of forming smaller nationalistic groupings. Empirical evidence shows increasing cohesion of European Political Groups and an increasing role of the European Parliament in EU inter-institutional decision making. As a consequence of this evolution, intergovernmentalism is being replaced with federalizing relations. The analysis can support positive expectations regarding the governability of the European Union after further enlargements provided that new member states have party systems fitting the European PoliticalGroups.

Correlative light and electron microscopy in parasite research.

The interaction of a parasite and a host cell is a complex process, which involves several steps: (1) attachment to the plasma membrane, (2) entry inside the host cell, and (3) hijacking of the metabolism of the host. In biochemical experiments, only an event averaged over the whole cell population can be analyzed. The power of microscopy, however, is to investigate individual events in individual cells. Therefore, parasitologists frequently perform experiments with fluorescence microscopy using different dyes to label structures of the parasite or the host cell. Though the resolution of light microscopy has greatly improved, it is not sufficient to reveal interactions at the ultrastructural level. Furthermore, only specifically labeled structures can be seen and related to each other. Here, we want to demonstrate the additional value of electron microscopy in this area of research. Investigation of the different steps of parasite-host cell interaction by electron microscopy, however, is often hampered by the fact that there are only a few cells infected, and therefore it is difficult to find enough cells to study. A solution is to profit from low magnification, hence large overview, and specific location of the players by fluorescence labels in a light microscope with the high power resolution and structural information provided by an electron microscope, in short by correlative light and electron microscopy.

Credible redistributive policies and migration across US States

Does worker mobility undermine governments ability to redistribute income? Thispaper analyzes the experience of US states in the recent decades. We build a tractablemodel where both migration decisions and redistribution policies are endogenous. Wecalibrate the model to match skill premium and worker productivity at the state level,as well as the size and skill composition of migration flows. The calibrated modelis able to reproduce the large changes in skill composition as well as key qualitativerelationships of labor flows and redistribution policies observed in the data. Our resultssuggest that regional di¤erences in labor productivity are an important determinantof interstate migration. We use the calibrated model to compare the cross-section ofredistributive policies with and without worker mobility. The main result of the paperis that interstate migration has induced substantial convergence in tax rates acrossUS states, but no race to the bottom. Skill-biased in-migration has reduced the skillpremium and the need for tax-based redistribution in the states that would have hadthe highest tax rates in the absence of mobility.

Analysis of acute brain slices by electron microscopy: A correlative light-electron microscopy workflow based on Tokuyasu cryo-sectioning.

Acute brain slices are slices of brain tissue that are kept vital in vitro for further recordings and analyses. This tool is of major importance in neurobiology and allows the study of brain cells such as microglia, astrocytes, neurons and their inter/intracellular communications via ion channels or transporters. In combination with light/fluorescence microscopies, acute brain slices enable the ex vivo analysis of specific cells or groups of cells inside the slice, e.g. astrocytes. To bridge ex vivo knowledge of a cell with its ultrastructure, we developed a correlative microscopy approach for acute brain slices. The workflow begins with sampling of the tissue and precise trimming of a region of interest, which contains GFP-tagged astrocytes that can be visualised by fluorescence microscopy of ultrathin sections. The astrocytes and their surroundings are then analysed by high resolution scanning transmission electron microscopy (STEM). An important aspect of this workflow is the modification of a commercial cryo-ultramicrotome to observe the fluorescent GFP signal during the trimming process. It ensured that sections contained at least one GFP astrocyte. After cryo-sectioning, a map of the GFP-expressing astrocytes is established and transferred to correlation software installed on a focused ion beam scanning electron microscope equipped with a STEM detector. Next, the areas displaying fluorescence are selected for high resolution STEM imaging. An overview area (e.g. a whole mesh of the grid) is imaged with an automated tiling and stitching process. In the final stitched image, the local organisation of the brain tissue can be surveyed or areas of interest can be magnified to observe fine details, e.g. vesicles or gold labels on specific proteins. The robustness of this workflow is contingent on the quality of sample preparation, based on Tokuyasu's protocol. This method results in a reasonable compromise between preservation of morphology and maintenance of antigenicity. Finally, an important feature of this approach is that the fluorescence of the GFP signal is preserved throughout the entire preparation process until the last step before electron microscopy.

Topological locking restrains replication fork reversal.

Two-dimensional agarose gel electrophoresis, psoralen cross-linking, and electron microscopy were used to study the effects of positive supercoiling on fork reversal in isolated replication intermediates of bacterial DNA plasmids. The results obtained demonstrate that the formation of Holliday-like junctions at both forks of a replication bubble creates a topological constraint that prevents further regression of the forks. We propose that this topological locking of replication intermediates provides a biological safety mechanism that protects DNA molecules against extensive fork reversals.