15 research outputs found
Generalisability of vaccine effectiveness estimates: an analysis of cases included in a postlicensure evaluation of 13-valent pneumococcal conjugate vaccine in the USA
External validity, or generalisability, is the measure of how well results from a study pertain to individuals in the target population. We assessed generalisability, with respect to socioeconomic status, of estimates from a matched caseācontrol study of 13-valent pneumococcal conjugate vaccine effectiveness for the prevention of invasive pneumococcal disease in children in the USA
Volume 02
Introduction from Dean Dr. Charles Ross
Mike\u27s Nite: New Jazz for an Old Instrument by Joseph A. Mann
Investigation of the use of Cucumis Sativus for Remediation Of Chromium from Contaminated Environmental Matrices: An Interdisciplinary Instrumental Analysis Project by Kathryn J. Greenly, Scott E. Jenkins, and Andrew E. Puckette
Development of GC-MS and Chemometric Methods for the Analysis of Accelerants in Arson Cases by Scott Jenkins
Building and Measuring Scalable Computing Systems by Daniel M. Honey and Jeffery P. Ravenhorst
Nomini Hall: A Case Study in the Use of Archival Resources as Guides for Excavation at An Archaeological Site by Jamie Elizabeth Mesrobian
Two Stories: In Ohio and How to Stay Out of the Brazilian Army by Thomas Scott
Forgerson des Hommes/Stealing the Steel in Zola\u27s Men by Jay Crowell
Paul Gauguin\u27s Escape into Primitivism by Sarah Spangenberg
Lee Krasner, Abstract Expressionist by Amy S. Eason
Artist Book āParisā by Kenny Wolfe
Artist Book āSequence of Every Dayā by Liz Hale
Artist Book āApple Treeā by Rachel Bouchard
Artist Book āNot so Pretty in Pinkā by Will Semonco
Artist Book āLook into the Moonā by Carley York
Artist Books āExtraā and āGreenā by Ryan Higgenbothom
Artist Book āRe-growing Appalachiaā by Adrienne Heinbaugh
Artist Books āCheeziestā, āUh-ohā and āThe Girl with the Glassesā by Melissa Dorton
āSelf-Reflectionā by Madeline Hunter
Artist Book āThe Princess and the Frogā by June Ashmore
āHunterās Nicheā and āThe Wildā by Clark Barkley
āTo Thine Own Self be Trueā by Jay Haley
āNot Funnyā Ten-Minute Play Festiva
Body size distributions signal a regime shift in a lake ecosystem
Communities of organisms, from mammals to microorganisms, have discontinuous distributions of body size. This pattern of size structuring is a conservative trait of community organization and is a product of processes that occur at multiple spatial and temporal scales. In this study, we assessed whether body size patterns serve as an indicator of a threshold between alternative regimes. Over the past 7000 years, the biological communities of Foy Lake (Montana, USA) have undergone a major regime shift owing to climate change. We used a palaeoecological record of diatom communities to estimate diatom sizes, and then analysed the discontinuous distribution of organism sizes over time. We used Bayesian classification and regression tree models to determine that all time intervals exhibited aggregations of sizes separated by gaps in the distribution and found a significant change in diatom body size distributions approximately 150 years before the identified ecosystem regime shift. We suggest that discontinuity analysis is a useful addition to the suite of tools for the detection of early warning signals of regime shifts
Prolonged instability prior to a regime shift
Regime shifts are generally defined as the point of 'abrupt' change in the state of a system. However, a seemingly abrupt transition can be the product of a system reorganization that has been ongoing much longer than is evident in statistical analysis of a single component of the system. Using both univariate and multivariate statistical methods, we tested a long-term high-resolution paleoecological dataset with a known change in species assemblage for a regime shift. Analysis of this dataset with Fisher Information and multivariate time series modeling showed that there was a, 2000 year period of instability prior to the regime shift. This period of instability and the subsequent regime shift coincide with regional climate change, indicating that the system is undergoing extrinsic forcing. Paleoecological records offer a unique opportunity to test tools for the detection of thresholds and stable-states, and thus to examine the long-term stability of ecosystems over periods of multiple millennia
Effect of osmotic shock as a management strategy to reduce transfers of non-indigenous species among low-salinity ports by ships
Open-ocean ballast-water exchange (BWE) is currently the most common treatment used to reduce the ballast transfer of organisms and the subsequent risk of invasions among coastal ecosystems. Freshwater or estuarine organisms remaining after BWE often experience high mortality, due to osmotic shock caused by high-salinity exposure. We conducted 70 salinity tolerance experiments on 54 different taxa to measure mortality rates of freshwater and estuarine organisms after exposure to oceanic seawater (34 psu), simulating both flow-through (F-T) and empty-refill (E-R) BWE methods. We focused especially on larval and adult crustaceans from freshwater and mesohaline habitats adjacent to ports of the Baltic Sea, North Sea, Great Lakes, Chesapeake Bay, and San Francisco Bay. Animals from oligohaline habitats (0-2 psu) experienced the highest mortality: all individuals died in 82% of the F-T treatments and 88% of the E-R treatments. The effectiveness of both treatment types decreased with animals from low-salinity (2-5 psu, 100% mortality in 27% of F-T and 46% of E-R treatments) and mesohaline habitats (5-18 psu, 100% mortality in 40% of F-T and 52% of E-R treatments). In 43% of cases among all salinity categories, empty-refill treatments required less exposure time to cause significant mortality than flow-through treatments. Invertebrates that exhibited significant survivorship were most often peracarid crustaceans including widely introduced species of mysid shrimps and amphipods. Although salinity shock does not completely prevent the transfer of all low-salinity biota, BWE provides a useful management tool to reduce species transfers, especially considering the combined effects of removal and mortality
The variance of two diatom species.
<p>While <i>Cymbella cymbiformis</i> displayed a pattern of increasing variance prior to ā¼1.3 ka, <i>Amphora veneta</i> did not. Conflicting patterns make it difficult to use univariate statistics to characterize the behavior of a complex multivariate system.</p
Normalized diatom species abundance for all species (A) and mean Fisher Information (B) for Foy Lake.
<p>Prior to ā¼4.5 ka the system had episodic fluctuations in species composition and mean FI, but the overall mean of the FI is unchanging; this suggests that this period was a stable regime characterized by high variability. At ā¼4.5 ka species evenness decreases, and the system begins a ā¼2 kyr gradual decrease in mean FI. Decreases in FI suggest the system is becoming unstable; as instability increases resilience decreases, warning of a possible regime shift. The system was in this unstable transitional period until ā¼2 ka, but it did not attain a new stable-state until ā¼1.3 ka.</p
Early warning signals of regime shifts applied to 109 diatom species from Foy Lake.
<p>Several populations of species experienced increased variability in the Foy Lake record; this increased variability peaks prior to ā¼1.3 ka (<b>A</b>). Skewness (<b>B</b>), kurtosis (<b>C</b>), and critical slowing down (<b>D</b>) show no clear trends, although, slight frequency changes can be detected at approximately ā¼4.5 ka and ā¼2.0 ka.</p
The first three significant axes of the multivariate time-series modeling.
<p>The proportion of variance explained by each axis is 29%, 18%, and 8% respectively. The amplitude of the frequency is low in axis one (<b>A</b>) with a major shift in score at ā¼1.7 ka, indicating a regime shift to an alternate state. This regime shift occurred when the lake changed from a shallow lake dominated by benthic taxa to a deep lake dominated by planktic taxa. Frequency pattern changes are present in axes two (<b>B</b>) and three (<b>C</b>) at ā¼4.8ā5 ka and ā¼2ā1.3 ka, at the beginning and the end of the period of instability.</p