1,320 research outputs found
Anthropomorphizing Science: How Does It Affect the Development of Evolutionary Concepts?
Despite the ubiquitous use of anthropomorphic language to describe biological change in both educational settings and popular science, little is known about how anthropomorphic language influences childrenās understanding of evolutionary concepts. In an experimental study, we assessed whether the language used to convey evolutionary concepts influences childrenās (5- to 12-year-olds; N = 88) understanding of evolutionary change. Language was manipulated by using three types of narrative, each describing animalsā biological change: (a) need-based narratives, which referenced animalsā basic survival needs; (b) desire-based or anthropomorphic narratives, which referenced animalsā mental states; and (c) scientifically accurate natural selection narratives. Results indicate that the language used to describe evolutionary change influenced childrenās endorsement of and use of evolutionary concepts when interpreting that change. Narratives using anthropomorphic language were least likely to facilitate a scientifically accurate interpretation. In contrast, need-based and natural selection language had similar and positive effects, which suggests that need-based reasoning might provide a conceptual scaffold to an evolutionary explanation of biological origins. In sum, the language used to teach evolutionary change impacts conceptual understanding in children and has important pedagogical implications for science education
A decadally-resolved paleohurricane record archived in the late Holocene sediments of a Florida sinkhole
Author Posting. Ā© The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Marine Geology 287 (2011): 14-30, doi:10.1016/j.margeo.2011.07.001.A 4500-year record of hurricane-induced storm surges is developed from sediment cores
collected from a coastal sinkhole near Apalachee Bay, Florida. Recent deposition of sand layers
in the upper sediments of the pond was found to be contemporaneous with significant, historic
storm surges at the site modeled using SLOSH and the Best Track, post-1851 A.D. dataset.
Using the historic portion of the record for calibration, paleohurricane deposits were identified
by sand content and dated using radiocarbon-based age models. Marine-indicative foraminifera,
some originating at least 5 km offshore, were present in several modern and ancient storm
deposits. The presence and long-term preservation of offshore foraminifera suggest that this site
and others like it may yield promising microfossil-based paleohurricane reconstructions in the
future. Due to the sub-decadal (~ 7 year) resolution of the record and the siteās high
susceptibility to hurricane-generated storm surges, the average, local frequency of recorded
events, approximately 3.9 storms per century, is greater than that of previously published
paleohurricane records from the region. The high incidence of recorded events permitted a time
series of local hurricane frequency during the last five millennia to be constructed. Variability in
the frequency of the largest storm layers was found to be greater than what would likely occur by
chance alone, with intervals of both anomalously high and low storm frequency identified.
However, the rate at which smaller layers were deposited was relatively constant over the last five millennia. This may suggest that significant variability in hurricane frequency has occurred
only in the highest magnitude events. The frequency of high magnitude events peaked near 6
storms per century between 2800 and 2300 years ago. High magnitude events were relatively
rare with about 0-3 storms per century occurring between 1900 to 1600 years ago and between
400 to 150 years ago. A marked decline in the number of large storm deposits, which began
around 600 years ago, has persisted through present with below average frequency over the last
150 years when compared to the preceding five millennia.Funding for this research was supported by the National Science Foundation and the
Coastal Ocean Institute. the model. The Florida State University Marine Laboratory provided lodging during fieldwork.
This research was completed during an American Meteorological Society Graduate Fellowship,
National Science Foundation Graduate Fellowship and Coastal Ocean Institute Fellowship. This
work was further supported by National Science Foundation award #OCE-0903020
Children's Developing Concepts of Ordinary and Extraordinary Minds: The Roles of Intuitive Theories and Cultural Input.
Individuals worldwide entertain ideas about beings with extraordinary mental capacities that far surpass ordinary human limits. How and when do such concepts develop? Two theories have been proposed to account for this development. A preparedness hypothesis states that young children are prepared to understand all minds as infallible, perhaps omniscient. A contrasting anthropomorphism hypothesis states that children's understanding of extraordinary minds builds upon their initial understanding of ordinary, limited minds. I assess these hypotheses in three studies.
In Study 1, secularly-schooled preschoolers completed theory-of-mind tasks about the mental states of contrasting agents, including ordinary humans, God, and Mr. Smartāwhom children were taught "knows everything." Consistent with an anthropomorphism hypothesis, 4-year-olds who were beginning to attribute mental limits to ordinary humans (e.g., ignorance) attributed those limits to God and to Mr. Smart. Only 5-year-olds differentiated between humans' fallible minds and extraordinary beings' less fallible minds. In Study 2, religiously-schooled preschoolers completed identical tasks, revealing a similar developmental pattern: 4-year-olds beginning to attribute certain limits to humans also attributed those limits to God. However, religiously-schooled 4-year-olds did not attribute those limits to Mr. Smart, whose powers they had just been instructed about. Across both studies, children who were more knowledgeable about God attributed to extraordinary beings less fallible capacities, but this was true only among children who understood ordinary humans' mental fallibilities.
Using different tasks with preschoolers, elementary-school children, and adults, Study 3 revealed that older preschoolers grant all-knowing beings knowledge of many (though not all) domains, including knowledge that ordinary people cannot easily acquire. Understanding the depth of all-knowing beings' knowledge (i.e., knowledge of everything within a domain) was not robust until early adulthood. Older preschoolers' exposure to ideas about God predicted attributions of broader knowledge to a new all-knowing being. Results from Studies 2 and 3 suggest that, after developing a representational theory-of-mind, socio-cultural input can facilitate an appreciation for extraordinary minds. Study 3 additionally identifies other cognitive competencies that support an understanding of omniscience. Collectively, these studies reveal that young children are clearly not prepared to understand extraordinary mental capacities, but instead such understanding develops progressively throughout childhood.Ph.D.PsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/89850/1/jonlane_1.pd
Assessing sedimentary records of paleohurricane activity using modeled hurricane climatology
Author Posting. Ā© American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 9 (2008): Q09V10, doi:10.1029/2008GC002043.Patterns of overwash deposition observed within back-barrier sediment archives can indicate past changes in tropical cyclone activity; however, it is necessary to evaluate the significance of observed trends in the context of the full range of variability under modern climate conditions. Here we present a method for assessing the statistical significance of patterns observed within a sedimentary hurricane-overwash reconstruction. To alleviate restrictions associated with the limited number of historical hurricanes affecting a specific site, we apply a recently published technique for generating a large number of synthetic storms using a coupled ocean-atmosphere hurricane model set to simulate modern climatology. Thousands of overwash records are generated for a site using a random draw of these synthetic hurricanes, a prescribed threshold for overwash, and a specified temporal resolution based on sedimentation rates observed at a particular site. As a test case we apply this Monte Carlo technique to a hurricane-induced overwash reconstruction developed from Laguna Playa Grande (LPG), a coastal lagoon located on the island of Vieques, Puerto Rico in the northeastern Caribbean. Apparent overwash rates in the LPG overwash record are observed to be four times lower between 2500 and 1000 years B.P. when compared to apparent overwash rates during the last 300 years. However, probability distributions based on Monte Carlo simulations indicate that as much as 65% of this drop can be explained by a reduction in the temporal resolution for older sediments due to a decrease in sedimentation rates. Periods of no apparent overwash activity at LPG between 2500 and 3600 years B.P. and 500ā1000 years B.P. are exceptionally long and are unlikely to occur (above 99% confidence) under the current climate conditions. In addition, breaks in activity are difficult to produce even when the hurricane model is forced to a constant El NiƱo state. Results from this study continue to support the interpretation that the western North Atlantic has exhibited significant changes in hurricane climatology over the last 5500 years.Funding for this research was provided by the Earth
Systems History Program of the National Science Foundation,
Risk Prediction Initiative, National Geographic Society, Coastal
Ocean Institute at WHOI, and the Andrew W. Mellon Foundation
Endowed Fund for Innovative Research
Tropical cyclone wind speed constraints from resultant storm surge deposition : a 2500 year reconstruction of hurricane activity from St. Marks, FL
Author Posting. Ā© American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 14 (2013): 2993ā3008, doi:10.1002/ggge.20217.Recent work suggests that the patterns of intense (ā„category 3 on the Saffir-Simpson scale) hurricane strikes over the last few millennia might differ from that of overall hurricane activity during this period. Prior studies typically rely on assigning a threshold storm intensity required to produce a sedimentological overwash signal at a particular coastal site based on historical analogs. Here, we improve on this approach by presenting a new inverse-model technique that constrains the most likely wind speeds required to transport the maximum grain size within resultant storm deposits. As a case study, the technique is applied to event layers observed in sediments collected from a coastal sinkhole in northwestern Florida. We find that (1) simulated wind speeds for modern deposits are consistent with the intensities for historical hurricanes affecting the site, (2) all deposits throughout the ā¼2500 year record are capable of being produced by hurricanes, and (3) a period of increased intense hurricane frequency is observed between ā¼1700 and ā¼600 years B.P. and decreased intense storm frequency is observed from ā¼2500 to ā¼1700 and ā¼600 years B.P. to the present. This is consistent with prior reconstructions from nearby sites. Changes in the frequency of intense hurricane strikes may be related to the degree of penetration of the Loop Current in the Gulf of Mexico.This work was supported by the National Science Foundation.2014-02-2
Aggression, Sibling Antagonism, and Theory of Mind During the First Year of Siblinghood: A Developmental Cascade Model
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/133634/1/cdev12530_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/133634/2/cdev12530.pd
Induced CNS expression of CXCL1 augments neurologic disease in a murine model of multiple sclerosis via enhanced neutrophil recruitment.
Increasing evidence points to an important role for neutrophils in participating in the pathogenesis of the human demyelinating disease MS and the animal model EAE. Therefore, a better understanding of the signals controlling migration of neutrophils as well as evaluating the role of these cells in demyelination is important to define cellular components that contribute to disease in MS patients. In this study, we examined the functional role of the chemokine CXCL1 in contributing to neuroinflammation and demyelination in EAE. Using transgenic mice in which expression of CXCL1 is under the control of a tetracycline-inducible promoter active within glial fibrillary acidic protein-positive cells, we have shown that sustained CXCL1 expression within the CNS increased the severity of clinical and histologic disease that was independent of an increase in the frequency of encephalitogenic Th1 and Th17 cells. Rather, disease was associated with enhanced recruitment of CD11b+ Ly6G+ neutrophils into the spinal cord. Targeting neutrophils resulted in a reduction in demyelination arguing for a role for these cells in myelin damage. Collectively, these findings emphasize that CXCL1-mediated attraction of neutrophils into the CNS augments demyelination suggesting that this signaling pathway may offer new targets for therapeutic intervention
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Disrupted CXCR2 Signaling in Oligodendroglia Lineage Cells Enhances Myelin Repair in a Viral Model of Multiple Sclerosis.
CXCR2 is a chemokine receptor expressed on oligodendroglia that has been implicated in the pathogenesis of neuroinflammatory demyelinating diseases as well as enhancement of the migration, proliferation, and myelin production by oligodendroglia. Using an inducible proteolipid protein (Plp) promoter-driven Cre-loxP recombination system, we were able to assess how timed ablation of Cxcr2 in oligodendroglia affected disease following intracranial infection with the neurotropic JHM strain of mouse hepatitis virus (JHMV). Generation of Plp-Cre-ER(T)::Cxcr2flox/flox transgenic mice (termed Cxcr2-CKO mice) allows for Cxcr2 to be silenced in oligodendrocytes in adult mice following treatment with tamoxifen. Ablation of oligodendroglia Cxcr2 did not influence clinical severity in response to intracranial infection with JHMV. Infiltration of activated T cells or myeloid cells into the central nervous system (CNS) was not affected, nor was the ability to control viral infection. In addition, the severity of demyelination was similar between tamoxifen-treated mice and vehicle-treated controls. Notably, deletion of Cxcr2 resulted in increased remyelination, as assessed by g-ratio (the ratio of the inner axonal diameter to the total outer fiber diameter) calculation, compared to that in vehicle-treated control mice. Collectively, our findings argue that CXCR2 signaling in oligodendroglia is dispensable with regard to contributing to neuroinflammation, but its deletion enhances remyelination in a preclinical model of the human demyelinating disease multiple sclerosis (MS).IMPORTANCE Signaling through the chemokine receptor CXCR2 in oligodendroglia is important for developmental myelination in rodents, while chemical inhibition or nonspecific genetic deletion of CXCR2 appears to augment myelin repair in animal models of the human demyelinating disease multiple sclerosis (MS). To better understand the biology of CXCR2 signaling on oligodendroglia, we generated transgenic mice in which Cxcr2 is selectively ablated in oligodendroglia upon treatment with tamoxifen. Using a viral model of neuroinflammation and demyelination, we demonstrate that genetic silencing of CXCR2 on oligodendroglia did not affect clinical disease, neuroinflammation, or demyelination, yet there was increased remyelination. These findings support and extend previous findings suggesting that targeting CXCR2 may offer a therapeutic avenue for enhancing remyelination in patients with demyelinating diseases
Observation of an optical spring with a beam splitter
We present the experimental observation of an optical spring without the use of an optical cavity. The optical spring is produced by interference at a beam splitter and, in principle, does not have the damping force associated with optical springs created in detuned cavities. The experiment consists of a MichelsonāSagnac interferometer (with no recycling cavities) with a partially reflective GaAs microresonator as the beam splitter that produces the optical spring. Our experimental measurements at input powers of up to 360 mW show the shift of the optical spring frequency as a function of power and are in excellent agreement with theoretical predictions. In addition, we show that the optical spring is able to keep the interferometer stable and locked without the use of external feedback
Rival male chemical cues evoke changes in male pre- and post-copulatory investment in a flour beetle
Copyright Ā© The Author 2015. Published by Oxford University Press on behalf of the
International Society for Behavioral Ecology.Supplementary material can be found at http://www.beheco.oxfordjournals.org/The files experiment 1, 2 and 3 are data files related to this paper āRival male chemical cues evoke changes in male pre- and post-copulatory investment in a flour beetleā.Males can gather information on the risk and intensity of sperm competition from their social environment. Recent studies have implicated chemosensory cues, for instance cuticular hydrocarbons (CHCs) in insects, as a key source of this information. Here, using the broad-horned flour beetle (Gnatocerus cornutus), we investigated the importance of contact-derived rival male CHCs in informing male perception of sperm competition risk and intensity. We experimentally perfumed virgin females with male CHCs via direct intersexual contact and measured male pre- and post-copulatory investment in response to this manipulation. Using chemical analysis, we verified that this treatment engendered changes to perfumed female CHC profiles, but did not make perfumed females āsmellā mated. Despite this, males responded to these chemical changes. Males increased courtship effort under low levels of perceived competition (from 1ā3 rivals), but significantly decreased courtship effort as perceived competition rose (from 3ā5 rivals). Furthermore, our measurement of ejaculate investment showed that males allocated significantly more sperm to perfumed females than to control females. Together, these results suggest that changes in female chemical profile elicited by contact with rival males do not provide males with information on female mating status, but rather inform males of the presence of rivals within the population and thus provide a means for males to indirectly assess the risk of sperm competition.Natural Environment Research CouncilRoyal SocietyLeverhulme Early Career Fellowshi
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