1,005 research outputs found

    The Life of Portland Cement

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    Perhaps just a word in explanation of the title of this paper will not be amiss. We speak of Portland Cement as possessing life. We do this because the duration of its existence as Portland Cement is measurable. In contradistinction we might speak of a material such as the Sioux Falls Quartzite as being dead, since no appreciable change takes place in the body of this Quartzite, all of the elements of the Quartzite being practically at a state of rest and resisting all disintegration by the ordinary weathering agencies. Perhaps our distinction may be somewhat arbitrary and we cheerfully invite helpful criticism

    Studies in the Solubility of Portland Cement Continued from 1908

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    In the year 1908 we presented a brief paper before the Academy of Science, calling attention to certain uses of Portland cement concrete for farm drainage and city sewer purposes and in that connection raised the question of the fitness of the material for the use made of it. The importance of the question has greatly increased, as the spirit of improvement and progress is running like wildfire over our state

    Those New Barley and Flax Varieties

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    Growers in northwestern Iowa will be hearing more about several new and improved varieties of barley and flax. Particularly promising varieties for Iowa are Traill and Liberty barley as well as Arny and Bolley flax

    Some Geological Aspects of Artificial Drainage in Iowa

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    Nature\u27s unfinished work in the Wisconsin drift areas of Iowa has left the lands peculiarly subject to submergence in times of heavy precipitation. The magnitude of the drainage projects which would be required to carry out the incomplete work of Nature\u27s young river systems, for a long time held back the development of drainage. Recent legislation, making possible the creation of drainage districts upon the petition of a reasonable number of land holders interested, has led to a most rapid growth in farm land drainage

    Developing Effective Faculty Competencies For Teaching International Business Topics

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    Faculty are increasingly called upon to teach topics in international business. To ensure teaching success, faculty need to develop knowledge of countries, international organizations, economies, culture, interpersonal skills in international settings, and foreign business practices. The purpose of the paper is to demonstrate how faculty can obtain the skills and knowledge necessary to teach international topics efficiently and cost effectively

    Museomics of a rare taxon: placing Whalleyanidae in the Lepidoptera Tree of Life

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    https://doi.org/10.1111/syen.12503Museomics is a valuable approach that utilizes the diverse biobanks that are natural history museums. The ability to sequence genomes from old specimens has expanded not only the variety of interesting taxa available to study but also the scope of questions that can be investigated in order to further knowledge about biodiversity. Here, we present whole genome sequencing results from the enigmatic genus Whalleyana (comprising two species - occurring in drier biomes of Madagascar - previously placed in a monotypic superfamily, Whalleyanoidea), as well as from certain species of the families Callidulidae and Hyblaeidae (Calliduloidea and Hyblaeoidea, respectively). Library preparation was carried out on four museum specimens and one existing DNA extract and sequenced with Illumina short reads. De novo assembly resulted in highly fragmented genomes with the N50 ranging from 317 to 2078 bp. Mining of a manually curated gene set of 331 genes from these draft genomes had an overall gene recovery rate of 64-90%. Phylogenetic analysis places Whalleyana as sister to Callidulidae and Hyblaea as sister to Pyraloidea. Since the former sister-group relationship turns out to be also supported by ten morphological synapomorphies, we propose to formally assign the Whalleyanidae to the superfamily Calliduloidea. These results highlight the usefulness of not only museum specimens but also existing DNA extracts, for whole genome sequencing and gene mining for phylogenomic studies.Peer reviewe

    Characterization of metalliferous sediment from a low-temperature hydrothermal environment on the Eastern Flank of the East Pacific Rise

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    Metalliferous deposits are described from the eastern flank of the East Pacific Rise (EPR) offshore Costa Rica, close to a basaltic seamount called “Dorado high”. Based on heat-flow data and porewater profiles, the site is an area of active low-temperature hydrothermal discharge. We focus on the mineralogical and chemical analysis from a 124 cm long gravity core (GC50), located on the northwestern slope of the 100 m high Dorado. In this core, the sediments consist of detrital clay minerals as well as authigenic minerals such as zeolites, apatites, and Fe/Mn-rich oxyhydroxides. In contrast, the reference sediments from adjacent areas without hydrothermal activity are olive gray hemipelagic muds composed of volcanic glass particles, clay minerals, siliceous microfossils, and some detrital quartz and feldspar. Bulk sediment chemistry and chemical enrichment factors calculated with respect to the reference sediment indicate that the most important chemical changes occurred at the base of the core from 100 to 124 cm bsf, with strong enrichments in MnO, CaO, P2O5, and Fe2O3. These enrichments are correlated with the occurrence of authigenic Fe-oxyhydroxide (goethite) and Mn oxide (todorokite and vernadite, at 100 cm bsf), and hydrothermal apatite (110–124 cm bsf). In the upper section of the core from 12 to 70 cm, the sediment is composed of abundant smectite and authigenic phillipsite, and only minor chemical changes can be observed with respect to the reference sediments. The ubiquitous presence of phillipsite suggests that the entire sedimentary column of core GC50 was first affected by diagenesis. However, below 70 cm bsf, these phillipsites are partially dissolved and Fe oxides occur from 110 to 124 cm, followed upward by Mn oxides at 100 cm. This transition from Fe to Mn-rich sediments can be interpreted in terms of an upward increasing redox potential. PAAS-normalized REY patterns of GC50 sediments present clearly negative Ce and positive Y anomalies inherited from seawater at the base of core GC50. These anomalies decrease upward, which we interpret together with the transition from Fe to Mn-rich sediments by an upward migrating low-temperature hydrothermal fluid. Thus, after a first stage of diagenesis, the discharge of a low-temperature hydrothermal fluid occurred through the sedimentary column, leading to the precipitation of hydrothermal compounds that are lacking towards the surface

    Value of individual surgeon performance metrics as quality assurance measures in oesophagogastric cancer surgery

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    Background Surgeon‐level operative mortality is widely seen as a measure of quality after gastric and oesophageal resection. This study aimed to evaluate this alongside a compound‐level outcome analysis. Methods Consecutive patients who underwent treatment including surgery delivered by a multidisciplinary team, which included seven specialist surgeons, were studied. The primary outcome was death within 30 days of surgery; secondary outcomes were anastomotic leak, Clavien–Dindo morbidity score, lymph node harvest, circumferential resection margin (CRM) status, disease‐free (DFS), and overall (OS) survival. Results The median number of annual resections per surgeon was 10 (range 5–25), compared with 14 (5–25) for joint consultant teams (P = 0·855). The median annual surgeon‐level mortality rate was 0 (0–9) per cent versus an overall network annual operative mortality rate of 1·8 (0–3·7) per cent. Joint consultant team procedures were associated with fewer operative deaths (0·5 per cent versus 3·4 per cent at surgeon level; P = 0·027). The median surgeon anastomotic leak rate was 12·4 (range 9–20) per cent (P = 0·625 versus the whole surgical range), overall morbidity 46·5 (31–60) per cent (P = 0·066), lymph node harvest 16 (9–29) (P < 0·001), CRM positivity 32·0 (16–46) per cent (P = 0·003), 5‐year DFS rate 44·8 (29–60) per cent and OS rate 46·5 (35–53) per cent. No designated metrics were independently associated with DFS or OS in multivariable analysis. Conclusion Annual surgeon‐level metrics demonstrated wide variations (fivefold), but these performance metrics were not associated with survival
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