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AlexanderWhatInfluencesWorldwide.pdf
No full textThe interplay of natural selection and genetic drift, influenced by geographic isolation, mating systems and population size, determines patterns of genetic diversity within species. The sperm whale provides an interesting example of a long-lived species with few geographic barriers to dispersal. Worldwide mtDNA diversity is relatively low, but highly structured among geographic regions and social groups, attributed to female philopatry. However, it is unclear whether this female philopatry is due to geographic regions or social groups, or how this might vary on a worldwide scale. To answer these questions, we combined mtDNA information for 1091 previously published samples with 542 newly obtained DNA profiles (394-bp mtDNA, sex, 13 microsatellites) including the previously unsampled Indian Ocean, and social group information for 541 individuals. We found low mtDNA diversity (π = 0.430%) reflecting an expansion event <80 000 years bp, but strong differentiation by ocean, among regions within some oceans, and among social groups. In comparison, microsatellite differentiation was low at all levels, presumably due to male-mediated gene flow. A hierarchical amova showed that regions were important for explaining mtDNA variance in the Indian Ocean, but not Pacific, with social group sampling in the Atlantic too limited to include in analyses. Social groups were important in partitioning mtDNA and microsatellite variance within both oceans. Therefore, both geographic philopatry and social philopatry influence genetic structure in the sperm whale, but their relative importance differs by sex and ocean, reflecting breeding behaviour, geographic features and perhaps a more recent origin of sperm whales in the Pacific. By investigating the interplay of evolutionary forces operating at different temporal and geographic scales, we show that sperm whales are perhaps a unique example of a worldwide population expansion followed by rapid assortment due to female social organization.Keywords: microsatellite genotypes, mtDNA, population expansion, Cetacea, population genetics, sex-biased dispersalKeywords: microsatellite genotypes, mtDNA, population expansion, Cetacea, population genetics, sex-biased dispersa
FalkKristenForestEcosystSocNonStructuralCarbohydratesWoody(SupportingInformation).pdf
No full textNon-structural carbohydrates (NSC) in plant tissue are frequently quantified to make inferences about plant responses to environmental conditions. Laboratories publishing estimates of NSC of woody plants use many different methods to evaluate NSC. We asked whether NSC estimates in the recent literature could be quantitatively compared among studies. We also asked whether any differences among laboratories were related to the extraction and quantification methods used to determine starch and sugar concentrations. These questions were addressed by sending sub-samples collected from five woody plant tissues, which varied in NSC content and chemical composition, to 29 laboratories. Each laboratory analyzed the samples with their laboratory-specific protocols, based on recent publications, to determine concentrations of soluble sugars, starch and their sum, total NSC. Laboratory estimates differed substantially for all samples. For example, estimates for Eucalyptus globulus leaves (EGL) varied from 23 to 116 (mean = 56) mg g⁻¹ for soluble sugars, 6–533 (mean = 94) mg g⁻¹ for starch and 53–649 (mean = 153) mg g⁻¹ for total NSC. Mixed model analysis of variance showed that much of the variability among laboratories was unrelated to the categories we used for extraction and quantification methods (method category R² = 0.05–0.12 for soluble sugars, 0.10–0.33 for starch and 0.01–0.09 for total NSC). For EGL, the difference between the highest and lowest least squares means for categories in the mixed model analysis was 33 mg g⁻¹ for total NSC, compared with the range of laboratory estimates of 596 mg g⁻¹. Laboratories were reasonably consistent in their ranks of estimates among tissues for starch (r = 0.41–0.91), but less so for total NSC (r = 0.45–0.84) and soluble sugars (r = 0.11–0.83). Our results show that NSC estimates for woody plant tissues cannot be compared among laboratories. The relative changes in NSC between treatments measured within a laboratory may be comparable within and between laboratories, especially for starch. To obtain comparable NSC estimates, we suggest that users can either adopt the reference method given in this publication, or report estimates for a portion of samples using the reference method, and report estimates for a standard reference material. Researchers interested in NSC estimates should work to identify and adopt standard methods.Keywords: standardization, particle size, reference method, starch, non-structural carbohydrate chemical analysis, soluble sugars, extraction and quantification consistencyKeywords: standardization, particle size, reference method, starch, non-structural carbohydrate chemical analysis, soluble sugars, extraction and quantification consistenc
Comparative hazard analysis and toxicological modeling of diverse nanomaterials using the embryonic zebrafish (EZ) metric of toxicity
Full text linkThe integration of rapid assays, large datasets, informatics, and modeling can overcome current barriers in understanding nanomaterial structure–toxicity relationships by providing a weight-of-the-evidence mechanism to generate hazard rankings for nanomaterials. Here, we present the use of a rapid, low-cost assay to perform screening-level toxicity evaluations of nanomaterials in vivo. Calculated EZ Metric scores, a combined measure of morbidity and mortality in developing embryonic zebrafish, were established at realistic exposure levels and used to develop a hazard ranking of diverse nanomaterial toxicity. Hazard ranking and clustering analysis of 68 diverse nanomaterials revealed distinct patterns of toxicity related to both the core composition and outermost surface chemistry of nanomaterials. The resulting clusters guided the development of a surface chemistry-based model of gold nanoparticle toxicity. Our findings suggest that risk assessments based on the size and core composition of nanomaterials alone may be wholly inappropriate, especially when considering complex engineered nanomaterials. Research should continue to focus on methodologies for determining nanomaterial hazard based on multiple sub-lethal responses following realistic, low-dose exposures, thus increasing the availability of quantitative measures of nanomaterial hazard to support the development of nanoparticle structure–activity relationships.This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Springer. The published article can be found at: http://link.springer.com/journal/11051Keywords: Zebrafish, Nanoparticle, Surface chemistry, Informatics, ToxicityKeywords: Zebrafish, Nanoparticle, Surface chemistry, Informatics, Toxicit
Effects of Environmental Factors and Nutrient Availability on the Biochemical Composition of Algae for Biofuels Production: A Review
Full text linkDue to significant lipid and carbohydrate production as well as other useful properties such as high production of useful biomolecular substrates (e.g., lipids) and the ability to grow using non-potable water sources, algae are being explored as a potential high-yield feedstock for biofuels production. In both natural and engineered systems, algae can be exposed to a variety of environmental conditions that affect growth rate and cellular composition. With respect to the latter, the amount of carbon fixed in lipids and carbohydrates (e.g., starch) is highly influenced by environmental factors and nutrient availability. Understanding synergistic interactions between multiple environmental variables and nutritional factors is required to develop sustainable high productivity bioalgae systems, which are essential for commercial biofuel production. This article reviews the effects of environmental factors (i.e., temperature, light and pH) and nutrient availability (e.g., carbon, nitrogen, phosphorus, potassium, and trace metals) as well as cross-interactions on the biochemical composition of algae with a special focus on carbon fixation and partitioning of carbon from a biofuels perspective.This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by MDPI. The published article can be found at: http://www.mdpi.com/journal/energies.Keywords: algae, biofuel production, biochemical composition, environmental effectKeywords: algae, biofuel production, biochemical composition, environmental effec
Lauraceous Flowers from the Eocene of Vancouver Island: Tinaflora beardiae gen. et sp nov (Lauraceae)
Full text linkPremise of research. Twenty-one permineralized fossil flowers assignable to Lauraceae from the Eocene Appian Way locality on Vancouver Island, British Columbia, Canada, provide important anatomical and morphological data for interpreting evolutionary patterns in this diverse magnoliid family. Methodology. Consecutive anatomical sections were prepared using the cellulose acetate peel technique. Morphology and anatomy of the flowers were determined from anatomical sections, and three-dimensional reconstructions were rendered from serial sections using the software Amira. Pivotal results. Fossil flowers with oil bodies, trichomes, pollen, ovary anatomy, and other characters have allowed for the reconstruction of actinomorphic, pedicellate, and trimerous flowers with tepals in two whorls adnate to a shallow hypanthium. Nine fertile stamens occur in three whorls, the innermost of which bears paired glandular appendages, and a fourth whorl of sagittate staminodes surrounds the carpel. Anthers are tetrasporangiate. Stamens of the two outer whorls have median pollen sacs that are shorter than the two marginal pollen sacs. Third-whorl stamens have median pollen sacs that are longer than the marginal pollen sacs. Anthers of the first and second whorls are introrse, while the third-whorl anthers are extrorse. The fossil flowers have diagnostic characters of Lauraceae and are compared to flowers of extinct and extant taxa. Conclusions. The Eocene floral remains are assigned to Tinaflora beardiae gen. et sp. nov. We infer some aspects of floral biology based on different stages of development preserved among the fossils. The combination of well-preserved floral organs and in situ pollen is rare in the fossil record, allowing T. beardiae to expand the diversity of lauraceous floral morphology and provide further evidence for an Eocene radiation of the family in Laurasia.This is the publisher’s final pdf. The published article is copyrighted by University of Chicago Press and can be found at: http://www.press.uchicago.edu/ucp/journals/journal/ijps.htmlKeywords: Lauraceae, Eocene, Neocinnamomum, flowers, fossilsKeywords: Lauraceae, Eocene, Neocinnamomum, flowers, fossil
Jakes_Mary_Clare_1979_Plate2.jpg
No full textSurface and subsurface data are combined to determine the structure of the western half of the Simi fault system in the Las Posas and Camarillo Hills area. Cretaceous to Eocene sedimentary rocks, present only in the subsurface, are overlain by late Eocene to early Miocene nonmarine stata (Sespe Formation) and middle Miocene volcanics and sedimentary rocks (Conejo Volcanics and Topanga Formation undifferentiated), in part exposed in the Las Posas Hills. Late Miocene marine beds (Modelo Formation) are present in the subsurface in the Camarillo Hills and may crop out in the eastern Santa Rosa Valley. These rocks are overlain unconformably by marine Pliocene-Pleistocene beds (Saugus Formation), older and younger Quaternary alluvium, and alluvial fan deposits. Normal faults cause the Sespe to subside towards a thick volcanic pile, built up in the Conejo Hills in the middle Miocene. Volcanic rocks buttressed against and later overtopped these Sespe subsidence structures. Reverse faults in the Oxnard plain and the left-lateral Somis fault are truncated by the unconformity at the base of the Saugus. Miocene and older strata were broadly folded in the Las Posas anti-cline and Santa Rosa syncline prior to deposition of the Saugus Formation and displacement on the Simi fault zone. The Bailey fault, a northwest-trending range-front fault, shows reverse separation, commonly follows Sespe subsidence structures and north-dipping normal faults which cut the Sespe. The Camarillo Hills anticline, Springville dome and post-Saugus Las Posas anticline appear to be pressure ridges adjacent to the Simi fault system on the north. Older alluvium deposits are uplifted and warped. The Camarillo fault cut and warped older alluvium.Surface and subsurface data are combined to determine the structure of the western half of the Simi fault system in the Las Posas and Camarillo Hills area. Cretaceous to Eocene sedimentary rock
Cataloging monographic Web-based materials for non-catalogers: the development and implementation of M-Web
Full text linkPNLA Quarterly v. 66 no. 3 (Spring 2002) p. 21Like many Technical Services Departments around the country, Oregon State University has been struggling with how to provide access to “born digital” information. Within the Department and the Library, some tension exists between what information our library should be providing access to and what information our library realistically can provide access to. Unfortunately, as a department, Technical Services can’t always provide access to all desired information, especially as the volume of information accelerates faster then current staffing levels. As a result, OSU functions under the policy that subscription-based resources like E-Journals are cataloged and made available through our electronic catalog, and monographic web resources, not acquired through GPO (MARCIVE), generally are managed outside our electronic catalog on static web resources created by subject specialists. This solution is hardly ideal since it requires the user to know what kinds of resources are added to the online catalog. Moreover, since these monographic materials are located outside the catalog, patrons are unable to utilize the catalog’s robust searching features to locate potentially useful information.Keywords: Electronic resources cataloging, Monograph cataloging, Internet catalogingKeywords: Electronic resources cataloging, Monograph cataloging, Internet catalogin
PrahlFredrickCEOASBioticAbioticDegradationTable2.pdf
No full textLipid biomarkers in sediments are widely used to infer environmental conditions that have
occurred in the geological past, but these reconstructions require a careful consideration of the
biotic and abiotic processes that degrade and alter the lipid biomarker compositions before
and after deposition. In this paper, we use alkenones produced by haptophyte microalgae to
explore the range of effects of these degradative processes. Alkenones are now perhaps the
best studied of all biomarkers with several hundred papers on their occurrence in organisms,
seawater and sediments. Much information has been obtained on their degradation from
laboratory incubations and inferences from changes in their distribution in aquatic
environments. Although alkenones are often considered as more stable than many other lipid
classes, it is now clear that their distributions can be affected by processes such as prolonged
oxygen exposure, aerobic bacterial degradation and thiyl radical-induced stereomutation
processes which, in some cases, can lead to changes in the proportions of the alkenones used
in the U₃₇[superscript K′] temperature proxy. The same set of chemical and biological processes act on all
lipids in aquatic environments and, in cases where there is a marked difference in reactivity,
this may lead to significant changes in the biomarker distributions and relative proportions of
different lipid classes
Effects of environmental stress on intertidal mussel reproduction
Full text linkEnvironmental stress can negatively affect the ability of organisms to reproduce. Energetic trade-offs exist in all organisms, and under stress, energy may be allocated away from reproduction and towards physiological defense and repair mechanisms. The rocky intertidal environment is ideal for investigating the influence of environmental stress, as organisms are exposed to both terrestrial and marine conditions due to tidal fluctuation. Aerial exposure at low tide can lead to high temperature, desiccation, and oxidative stress. Stress in the intertidal zone increases along a vertical gradient, as organisms in the high intertidal are exposed to air for longer periods of time than those in the low intertidal.
Mussels are typically the dominant space-occupiers on temperate rocky shores, and they span the vertical gradient by occupying the entire mid-zone, from the low intertidal, which is a relatively low-stress environment, to the high intertidal, which is a high-stress environment. In this dissertation, we compared growth, reproduction, physiological defenses, pigmentation, and survival of mussels from the low-stress and high-stress regimes. We also compared energy allocation towards reproduction in mussels across a gradient of food availability between sites on the central Oregon coast. Findings indicate that growth and energy allocation towards reproduction are reduced in the high edge of the mussel bed, and physiological defenses are increased. A pattern was revealed where mussels in the high edge of the mussel bed are accumulating high concentrations of carotenoid pigments into their gonadal tissues, which was previously thought to be a secondary sex characteristic of females. This suggests that mussels may be incorporating carotenoids into their gonads in an effort to protect their gametes from damage by oxygen free radicals generated during aerial exposure.
Results of this research have implications for intertidal systems under climate change scenarios, as extreme aerial temperature events are predicted to increase in frequency and severity, and changes in oceanic circulation may also occur. Based on the findings presented in this dissertation, increases in aerial temperature could potentially lead to decreased energy allocation towards reproduction, changes in spawning time, and reduced survival of adult mussels
Attention Capture While Switching Search Strategies: Evidence for a Breakdown in Top-Down Attentional Control
Full text linkWhereas capture experiments typically repeat a single task many times, real world cognition is
characterized by frequent switching. Lien, Ruthruff, and Johnston (2010) reported that the
attentional control system can rapidly and fully switch between different search settings (e.g., red
to green), with no carryover and no inter-trial priming. The present study examined whether this
impressive flexibility is possible even when the switch is not between different features along the
same dimension, but between mutually incompatible search modes. On each trial, participants
were prompted to find and identify the letter that was in a specific color (feature search mode) or
was uniquely colored (singleton search mode). Within each block, search mode was either pure
or mixed; the mixed blocks contained a fixed AABB search sequence (singleton-singleton-feature-
feature) in Experiment 1 and a random sequence in Experiment 2. The target display was
preceded by a non-informative cue display containing a non-target color singleton. In pure
feature search blocks, these irrelevant singleton cues were generally unable to capture attention,
replicating previous findings of “contingent capture.” In mixed blocks, however, irrelevant color
singletons captured attention on feature search trials. This breakdown indicates a limitation in
the sharpness of attentional control following mode switches, which might be common in the
real world.Keywords: Cognitive Control and Switching, Visual Search Strategy, Attention CaptureKeywords: Cognitive Control and Switching, Visual Search Strategy, Attention Captur