2,278 research outputs found

    An Analysis of an Alternate-Year Walleye Fry Stocking Program in the Cedar River in Iowa

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    Year-class analysis of walleye, Stizostedion v. vitreum (Mitchill), taken by anglers in a portion of the Cedar River in Iowa indicated that alternate-year stocking of 3,500 fry per mile of river did not influence year-class abundance. Despite the short duration of the project, 1951-1958, a reasonably direct relationship between spring floods and spring air temperatures and year-class abundance was evident. Disparity in year-class abundance between samples taken 5 miles apart and within 3 months of each other, but by different methods (angling and chemical kill), indicates either a sampling selectivity or a relative discreteness or stability of portions of an assumed homogeneous population of river walleyes, or both

    Education in the working-class home: modes of learning as revealed by nineteenth-century criminal records

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    The transmission of knowledge and skills within the working-class household greatly troubled social commentators and social policy experts during the first half of the nineteenth century. To prove theories which related criminality to failures in working-class up-bringing, experts and officials embarked upon an ambitious collection of data on incarcerated criminals at various penal institutions. One such institution was the County Gaol at Ipswich. The exceptionally detailed information that survives on families, literacy, education and apprenticeships of the men, women and children imprisoned there has the potential to transform our understanding of the nature of home schooling (broadly interpreted) amongst the working classes in nineteenth-century England. This article uses data sets from prison registers to chart both the incidence and ‘success’ of instruction in reading and writing within the domestic environment. In the process, it highlights the importance of schooling in working-class families, but also the potentially growing significance of the family in occupational training

    The Arabidopsis thaliana mobilome and its impact at the species level

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    Transposable elements (TEs) are powerful motors of genome evolution yet a comprehensive assessment of recent transposition activity at the species level is lacking for most organisms. Here, using genome sequencing data for 211 Arabidopsis thaliana accessions taken from across the globe, we identify thousands of recent transposition events involving half of the 326 TE families annotated in this plant species. We further show that the composition and activity of the 'mobilome' vary extensively between accessions in relation to climate and genetic factors. Moreover, TEs insert equally throughout the genome and are rapidly purged by natural selection from gene-rich regions because they frequently affect genes, in multiple ways. Remarkably, loci controlling adaptive responses to the environment are the most frequent transposition targets observed. These findings demonstrate the pervasive, species-wide impact that a rich mobilome can have and the importance of transposition as a recurrent generator of large-effect alleles

    Tracking and modelling prices using web-scraped price microdata : towards automated daily consumer price index forecasting

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    With the increasing relevance and availability of on-line prices that we see today, it is natural to ask whether the prediction of the consumer price index (CPI), or related statistics, may usefully be computed more frequently than existing monthly schedules allow for. The simple answer is ‘yes’, but there are challenges to be overcome first. A key challenge, addressed by our work, is that web-scraped price data are extremely messy and it is not obvious, a priori, how to reconcile them with standard CPI statistics. Our research focuses on average prices and disaggregated CPI at the level of product categories (lager, potatoes, etc.) and develops a new model that describes the joint time evolution of latent daily log-inflation rates driving prices seen on the Internet and prices recorded in official surveys, with the model adapting to various product categories. Our model reveals the differing levels of dynamic behaviour across product category and, correspondingly, differing levels of predictability. Our methodology enables good prediction of product-category-specific CPI immediately before their release. In due course, with increasingly complete web-scraped data, combined with the best survey data, the prospect of more frequent intermonth aggregated CPI prediction is an achievable goal

    Political Party Mortality in Established Party Systems:A Hierarchical Competing Risks Approach

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    Existing scholarship offers few answers to fundamental questions about the mortality of political parties in established party systems. Linking party research to the organization literature, we conceptualize two types of party death, dissolution and merger, reflecting distinct theoretical rationales. They underpin a new framework on party organizational mortality theorizing three sets of factors: those shaping mortality generally and those shaping dissolution or merger death exclusively. We test this framework on a new data set covering the complete life cycles of 184 parties that entered 21 consolidated party systems over the last five decades, resorting to multilevel competing risks models to estimate the impact of party and country characteristics on the hazards of both types of death. Our findings not only show that dissolution and merger death are driven by distinct factors, but also that they represent separate logics not intrinsically related at either the party or systemic level
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