1,258 research outputs found
The distribution of cirripeds and gastropods on plain vertical rock surfaces in the upper intertidal and splash zones
This is a student paper done for a University of California Berkeley Zoology class. Since UCB didn't have its own marine lab at the time, it rented space at Hopkins Marine Station where this work was done. Cadet Hand earned his Ph.D. from Berkeley and went on to become Director of the Bodega Marine Laboratory. Donald Putnam Abbott also earned his Ph.D. from Berkeley and later became a Stanford professor at Hopkins Marine Station. (PDF contains 26 pages
Are Midsize Academic Libraries on the Right E-Book Train?
Librarians and their vendors were invited to a lively lunch discussion of the fate of books in midsize academic libraries. Do the monograph acquisition models advocated by many R-1 librarians at recent Charleston Conferences fit the needs of midsize academic libraries? These radical new models appear to assume almost full migration to e-books and include such strategies as wholesale movement to e-book-only approval; large leased e-book packages; and expansive DDA offerings of e-books in the catalog. Should midsize academic libraries, which are more often faced with unpredictable budget cycles, limited resources, and a different set of priorities, follow the R-1’s lead, or should they find monograph acquisition models better suited to their needs? Participants had the opportunity to explore these issues with the moderators’ guidance and to offer ideas on blending the best of the emerging R-1 models with the differing needs of midsize academic libraries
National Union Catalog: Asset or Albatross?
Midsize academic libraries face many unique challenges, particularly in the greyer areas of collection management. This presentation addresses these challenges faced by libraries in midsize institutions and how they differ from those at larger research institutions. It focuses on the presenters’ study of midsize library attitudes toward retaining or weeding the iconic National Union Catalog, Pre-1956 Imprints and the reasoning behind each. The generations of librarians who used the NUC and other analog sets are passing from the scene in academic libraries, and the incoming digital native librarian knows little or nothing about them. The fate of the NUC is examined. The example of de-selection decisions regarding voluminous paper sets of pre-digital finding aids is also discussed. Ultimately, the presentation aims to discuss the ways in which midsize libraries can find in building midsize library collections, which will balance out the research needs against the demands of limited space and budgets
Adios to Paper Journals—Removed and Recycled—One Mile Long and 75 Tons
This presentation uses Appalachian State University’s experiences as a stimulus for discussing how we have, and others may, successfully remove in a single swoop several thousand linear feet of little used bound periodicals. This effort opens library areas for new services and spaces. The program will be a resource and guide to others interested in large‐scale deaccessioning projects and includes three deaccessioning projects using online back files from 1) JSTOR; 2) ScienceDirect, Wiley, and Sage; and 3) journals outside of these packages
Stochastic Gravitational Wave Measurements with Bar Detectors: Dependence of Response on Detector Orientation
The response of a cross-correlation measurement to an isotropic stochastic
gravitational-wave background depends on the observing geometry via the overlap
reduction function. If one of the detectors being correlated is a resonant bar
whose orientation can be changed, the response to stochastic gravitational
waves can be modulated. I derive the general form of this modulation as a
function of azimuth, both in the zero-frequency limit and at arbitrary
frequencies. Comparisons are made between pairs of nearby detectors, such as
LIGO Livingston-ALLEGRO, Virgo-AURIGA, Virgo-NAUTILUS, and EXPLORER-AURIGA,
with which stochastic cross-correlation measurements are currently being
performed, planned, or considered.Comment: 17 pages, REVTeX (uses rcs, amsmath, hyperref, and graphicx style
files), 4 figures (8 eps image files
Molecular Design Parameters of Anthraquinone Dyes for Guest-Host Liquid-Crystal Applications : Experimental and Computational Studies of Spectroscopy, Structure and Stability
A set of five anthraquinone dyes with bis(4-propylphenyl) substituent groups, connected via sulfide or amine linkages at the 1,5-positions or directly at the 2,6-positions, have been studied in solution by UV-vis spectroscopy and electrochemistry, allied with density functional theory calculations of structures, electronic transitions, and redox potentials. The visible transitions and redox potentials are shown to vary with the HOMO and LUMO energies, with the variation in both color and redox stability between the dyes being attributable principally to variations in the HOMOs located mainly on the substituents and outer anthraquinone rings. The calculated molecular structures and visible transition dipole moments are shown to vary subtly with substituent, giving variations in the molecular aspect ratios, minimum moment of inertia axes, and transition dipole moment vector orientations that can rationalize the alignment trends reported in the literature for such anthraquinone dyes in liquid crystal hosts, showing why 1,5-disulfide and 2,6-diphenyl substituents give better designs than 1,5-diamine substituents. The computational approaches reported here are shown to give good matches with experimental trends, indicating that they may be used more generally to aid the rational molecular design of dyes for applications as guests in liquid crystal hosts
Variable and changing trajectories in youth athlete development: further verification in advocating a long-term inclusive tracking approach.
Athlete development through adolescence can vary greatly because of maturational processes. For example, variation can be observed in anthropometric and fitness measures with later maturing individuals "catching up" their earlier maturing peers at later time points. This study examined a methodological issue concerning how best to assess anthropometric and fitness change (i.e., "across age categories" or "per year") relative to an age and skill-matched population (N = 1,172). Furthermore, it examined changes in anthropometric and fitness characteristics in 3 cases of youth rugby league players (aged 13-15) across a 2-year period. Findings identified the "per year" method as generating less deviated z-scores across anthropometric and fitness measures (e.g., mean change p < 0.001), suggesting less substantial change in case players relative to the population. When applied to additional players, z-score and radar graphs showed developmental variability and longitudinal change. The possibility of a "later maturing player" increasing anthropometric (e.g., height: player 4 = 3.3 cm; player 5 = 13.2 cm; and player 6 = 15.7 cm) and fitness (e.g., 30-m sprint: player 4 = -0.18 s, player 5 = -0.46 s, and player 6 = -0.59 s) characteristics compared with early maturing players was confirmed. Findings affirm the potential for variable and changing trajectories in adolescent athletes. Practical implications advocate a long-term inclusive tracking approach of athletes, the avoidance of (de)selection, and the reduction of a performance emphasis in adolescent stages of sport systems
Molecular Dynamics Simulations of Liquid and Polymer Electrolytes for Energy Storage Devices
Advancing beyond current lithium-ion technology is necessary in order to enable energy storage devices for electric airplanes. Electrolyte stability is a key limiting factor, yet the design of improved electrolytes remains a formidable challenge. Molecular dynamics (MD) simulations are a powerful tool for studying electrolytes, since they can be used to evaluate structural, thermodynamic, and transport properties, and can provide molecular-level detail often inaccessible to experimental techniques. Our computational materials groups at the NASA Ames Research Center has developed models and methods to accurately simulate both liquid and polymer electrolytes.We report the results from atomistic MD simulations of several electrolyte materials, with lithium salts dissolved in ionic liquids, dimethoxyethane (DME), and polyethylene oxide (PEO). For improved accuracy, we employ polarizable models, where each atom is given an environment-dependent atomic dipole. The simulations accurately predict bulk transport properties, including viscosity, diffusion, and ionic conductivity, in quantitative agreement with available experimental data. Moreover, the simulations provide important insights into the solvation structure of the lithium ions.We also report the results from coarse-grained MD simulations of polyanion electrolytes. In order to more efficiently capture the longer length- and time-scales of these systems, we employ a generic bead-spring model. These simulations provide important insight into how the polymer chain architecture and ionic interaction strengths affect the ionic aggregation behavior and cation dynamics. Despite the simplicity of the model, the simulations yield qualitative agreement with experimental data for similar systems
Reheating Temperature and Inflaton Mass Bounds from Thermalization After Inflation
We consider the conditions for the decay products of perturbative inflaton
decay to thermalize. The importance of considering the full spectrum of
inflaton decay products in the thermalization process is emphasized. It is
shown that the delay between the end of inflaton decay and thermalization
allows the thermal gravitino upper bound on the reheating temperature to be
raised from 10^{8} GeV to as much as 10^{12} GeV in realistic inflation models.
Requiring that thermalization occurs before nucleosynthesis imposes an upper
bound on the inflaton mass as a function of the reheating temperature, m_{S} <
10^{10} (T_{R}/1 GeV)^{7/9} GeV. It is also shown that even in realistic
inflation models with relatively large reheating temperatures, it is
non-trivial to have thermalization before the electroweak phase transition
temperature. Therefore the thermal history of the Universe is very sensitive to
details of the inflation model.Comment: 12 Pages LaTeX. Catalysed thermalization discussion correcte
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Plasma sTNFR1 and IL8 for prognostic enrichment in sepsis trials: a prospective cohort study.
BackgroundEnrichment strategies improve therapeutic targeting and trial efficiency, but enrichment factors for sepsis trials are lacking. We determined whether concentrations of soluble tumor necrosis factor receptor-1 (sTNFR1), interleukin-8 (IL8), and angiopoietin-2 (Ang2) could identify sepsis patients at higher mortality risk and serve as prognostic enrichment factors.MethodsIn a multicenter prospective cohort study of 400 critically ill septic patients, we derived and validated thresholds for each marker and expressed prognostic enrichment using risk differences (RD) of 30-day mortality as predictive values. We then used decision curve analysis to simulate the prognostic enrichment of each marker and compare different prognostic enrichment strategies.Measurements and main resultsAn admission sTNFR1 concentration > 8861 pg/ml identified patients with increased mortality in both the derivation (RD 21.6%) and validation (RD 17.8%) populations. Among immunocompetent patients, an IL8 concentration > 94 pg/ml identified patients with increased mortality in both the derivation (RD 17.7%) and validation (RD 27.0%) populations. An Ang2 level > 9761 pg/ml identified patients at 21.3% and 12.3% increased risk of mortality in the derivation and validation populations, respectively. Using sTNFR1 or IL8 to select high-risk patients improved clinical trial power and efficiency compared to selecting patients with septic shock. Ang2 did not outperform septic shock as an enrichment factor.ConclusionsThresholds for sTNFR1 and IL8 consistently identified sepsis patients with higher mortality risk and may have utility for prognostic enrichment in sepsis trials
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