142 research outputs found
Abfs and Cbfs in Cotton (Gossypium Hirsutum): A Characterization and Functional Analysis in Response to Abiotic Stress
Abiotic stress is pernicious; every year causing substantial reductions in agricultural yield. Despite this, due to the complex nature of the plant response, our current understanding of the molecular mechanisms and signaling pathways is limited. Among the gene families shown to play a role in dehydration and low temperature tolerance are the ABFs and CBFs. Both are small families of transcription factors, are expressed in response to abiotic stress, and have been shown to increase abiotic stress tolerance when ectopically expressed. Here, both of these families are isolated and functionally characterized in G. hirsutum (cotton), the most important global natural fiber source. Gene expression analyses illustrate how these genes respond to abiotic stress, and ectopic expression in Arabidopsis illustrates their functionality. Ectopic expression of abiotic stress-related genes has often been shown to increase stress tolerance, however, at a developmental cost. Therefore, a more in-depth understanding of the abiotic stress response is necessary to develop crops able to withstand abiotic stress and at the same time minimize developmental delays.Biochemistry & Molecular Biolog
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The role of interest in memory for trivia questions: an investigation with a large-scale database
The importance of interest for memory performance has been established in previous studies. One way to induce interest in experiments is to use trivia questions. However, previous studies have used only a limited number of trivia questions and these questions differ substantially across studies, making it difficult to ensure the comparability and generalizability of the findings. Most of these studies also have not differentiated between interest in the trivia question itself and interest in the corresponding answer. To address these issues, the current study established a normative database for 244 trivia questions with a large sample (N = 1,498) and examined how pre-answer interest (i.e., interest in the question) and post-answer interest (i.e., interest in the answer) relate to learning performance. Participants were presented with trivia questions, asked to provide their best guess for the answer, rated their confidence in the guess, and indicated their interest in learning the true answer. Following the presentation of the answer, participants indicated their post-answer interest. One week later, participants were given a memory test on the questions. A multilevel structural equation model revealed that the positive relationship between pre-answer interest and memory was mostly mediated by post-answer interest (i.e., interest in the questionsâ answer). Confidence had both a direct and a mediated effect (over interest) on memory. These results provide a more fine-grained analysis of how interest can fuel learning
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When enough is not enough: information overload and metacognitive decisions to stop studying information
People are often exposed to more information than they can actually remember. Despite this frequent form of information overload, little is known about how much information people choose to remember. Using a novel âstopâ paradigm, the current research examined whether and how people choose to stop receiving newâpossibly overwhelmingâinformation with the intent to maximize memory performance. Participants were presented with a long list of items and were rewarded for the number of correctly remembered words in a following free recall test. Critically, participants in a stop condition were provided with the option to stop the presentation of the remaining words at any time during the list, whereas participants in a control condition were presented with all items. Across five experiments, we found that participants tended to stop the presentation of the items to maximize the number of recalled items, but this decision ironically led to decreased memory performance relative to the control group. This pattern was consistent even after controlling for possible confounding factors (e.g., task demands). The results indicated a general, false belief that we can remember a larger number of items if we restrict the quantity of learning materials. These findings suggest people have an incomplete understanding of how we remember excessive amounts of information
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Metacognition and proofreading: the roles of aging, motivation, and interest
Objectives: The current study examined younger and older adultsâ error detection accuracy, prediction calibration, and postdiction calibration on a proofreading task, to determine if age-related difference would be present in this type of common error detection task.
Method: Participants were given text passages, and were first asked to predict the percentage of errors they would detect in the passage. They then read the passage and circled errors (which varied in complexity and locality), and made postdictions regarding their performance, before repeating this with another passage and answering a comprehension test of both passages.
Results: There were no age-related differences in error detection accuracy, text comprehension, or metacognitive calibration, though participants in both age groups were overconfident overall in their metacognitive judgments. Both groups gave similar ratings of motivation to complete the task. The older adults rated the passages as more interesting than younger adults did, although this level of interest did not appear to influence error-detection performance.
Discussion: The age equivalence in both proofreading ability and calibration suggests that the ability to proofread text passages and the associated metacognitive monitoring used in judging oneâs own performance are maintained in aging. These age-related similarities persisted when younger adults completed the proofreading tasks on a computer screen, rather than with paper and pencil. The findings provide novel insights regarding the influence that cognitive aging may have on metacognitive accuracy and text processing in an everyday task
Measuring movement fluency during the sit-to-walk task
Restoring movement fluency is a key focus for physical rehabilitation; it's measurement, however, lacks objectivity. The purpose of this study was to find whether measurable movement fluency variables differed between groups of adults with different movement abilities whilst performing the sit-to-walk (STW) movement. The movement fluency variables were: (1) hesitation during movement (reduction in forward velocity of the centre of mass; CoM), (2) coordination (percentage of temporal overlap of joint rotations) and (3) smoothness (number of inflections in the CoM jerk signal)
State of the Art in Large-Scale Soil Moisture Monitoring
Soil moisture is an essential climate variable influencing land atmosphere interactions, an essential hydrologic variable impacting rainfall runoff processes, an essential ecological variable regulating net ecosystem exchange, and an essential agricultural variable constraining food security. Large-scale soil moisture monitoring has advanced in recent years creating opportunities to transform scientific understanding of soil moisture and related processes. These advances are being driven by researchers from a broad range of disciplines, but this complicates collaboration and communication. For some applications, the science required to utilize large-scale soil moisture data is poorly developed. In this review, we describe the state of the art in large-scale soil moisture monitoring and identify some critical needs for research to optimize the use of increasingly available soil moisture data. We review representative examples of 1) emerging in situ and proximal sensing techniques, 2) dedicated soil moisture remote sensing missions, 3) soil moisture monitoring networks, and 4) applications of large-scale soil moisture measurements. Significant near-term progress seems possible in the use of large-scale soil moisture data for drought monitoring. Assimilation of soil moisture data for meteorological or hydrologic forecasting also shows promise, but significant challenges related to model structures and model errors remain. Little progress has been made yet in the use of large-scale soil moisture observations within the context of ecological or agricultural modeling. Opportunities abound to advance the science and practice of large-scale soil moisture monitoring for the sake of improved Earth system monitoring, modeling, and forecasting
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First use of a HyViSI H4RG for Astronomical Observations
We present the first astronomical results from a 4K2 Hybrid Visible Silicon PIN array detector (HyViSI) read out with the Teledyne Scientific and Imaging SIDECAR ASIC. These results include observations of astronomical standards and photometric measurements using the 2.1m KPNO telescope. We also report results from a test program in the Rochester Imaging Detector Laboratory (RIDL), including: read noise, dark current, linearity, gain, well depth, quantum efficiency, and substrate voltage effects. Lastly, we highlight results from operation of the detector in window read out mode and discuss its potential role for focusing, image correction, and use as a telescope guide camera
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I owe you: age-related similarities and differences in associative memory for gains and losses
Older adults often experience associative memory impairments but can sometimes remember important information. The current experiments investigate potential age-related similarities and differences associate memory for gains and losses. Younger and older participants were presented with faces and associated dollar amounts, which indicated how much money the person âowedâ the participant, and were later given a cued recall test for the dollar amount. Experiment 1 examined face-dollar amount pairs while Experiment 2 included negative dollar amounts to examine both gains and losses. While younger adults recalled more information relative to older adults, both groups were more accurate in recalling the correct value associated with high value faces compared to lower value faces and remembered gist-information about the values. However, negative values (losses) did not have a strong impact on recall among older adults versus younger adults, illustrating important associative memory differences between younger and older adults
Supersymmetric Dark Matter
There is almost universal agreement among astronomers that most of the mass
in the Universe and most of the mass in the Galactic halo is dark. Many lines
of reasoning suggest that the dark matter consists of some new, as yet
undiscovered, weakly-interacting massive particle (WIMP). There is now a vast
experimental effort being surmounted to detect WIMPS in the halo. The most
promising techniques involve direct detection in low-background laboratory
detectors and indirect detection through observation of energetic neutrinos
from annihilation of WIMPs that have accumulated in the Sun and/or the Earth.
Of the many WIMP candidates, perhaps the best motivated and certainly the most
theoretically developed is the neutralino, the lightest superpartner in many
supersymmetric theories. We review the minimal supersymmetric extension of the
Standard Model and discuss prospects for detection of neutralino dark matter.
We review in detail how to calculate the cosmological abundance of the
neutralino and the event rates for both direct- and indirect-detection schemes,
and we discuss astrophysical and laboratory constraints on supersymmetric
models. We isolate and clarify the uncertainties from particle physics, nuclear
physics, and astrophysics that enter at each step in the calculation. We
briefly review other related dark-matter candidates and detection techniques.Comment: The complete postscript file is available at
ftp://ftp.npac.syr.edu/pub/users/jungman/susyreview/susyreview.ps.Z The TeX
source and figures (plain TeX; macros included) are at
ftp://ftp.npac.syr.edu/pub/users/jungman/susyreview/susyreview.tar.Z Full
paper NOT submitted to lanl archive: table of contents only. To appear in
Physics Report
The density and peculiar velocity fields of nearby galaxies
We review the quantitative science that can be and has been done with
redshift and peculiar velocity surveys of galaxies in the nearby universe.
After a brief background setting the cosmological context for this work, the
first part of this review focuses on redshift surveys. The practical issues of
how redshift surveys are carried out, and how one turns a distribution of
galaxies into a smoothed density field, are discussed. Then follows a
description of major redshift surveys that have been done, and the local
cosmography out to 8,000 km/s that they have mapped. We then discuss in some
detail the various quantitative cosmological tests that can be carried out with
redshift data. The second half of this review concentrates on peculiar velocity
studies, beginning with a thorough review of existing techniques. After
discussing the various biases which plague peculiar velocity work, we survey
quantitative analyses done with peculiar velocity surveys alone, and finally
with the combination of data from both redshift and peculiar velocity surveys.
The data presented rule out the standard Cold Dark Matter model, although
several variants of Cold Dark Matter with more power on large scales fare
better. All the data are consistent with the hypothesis that the initial
density field had a Gaussian distribution, although one cannot rule out broad
classes of non-Gaussian models. Comparison of the peculiar velocity and density
fields constrains the Cosmological Density Parameter. The results here are
consistent with a flat universe with mild biasing of the galaxies relative to
dark matter, although open universe models are by no means ruled out.Comment: In press, Physics Reports. 153 pages. gzip'ed postscript of text plus
20 embedded figures. Also available via anonymous ftp at
ftp://eku.ias.edu/pub/strauss/review/physrep.p
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