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排序方式: 共有175条查询结果,搜索用时 148 毫秒
1.
Shoudong Wang Shulin Liu Jie Wang Kengo Yokosho Bin Zhou Ya-Chi Yu Zhi Liu Wolf B Frommer Jian Feng Ma Li-Qing Chen Yuefeng Guan Huixia Shou Zhixi Tian 《国家科学评论(英文版)》2020,7(11):1776
Soybean accounts for more than half of the global production of oilseed and more than a quarter of the protein used globally for human food and animal feed. Soybean domestication involved parallel increases in seed size and oil content, and a concomitant decrease in protein content. However, science has not yet discovered whether these effects were due to selective pressure on a single gene or multiple genes. Here, re-sequencing data from >800 genotypes revealed a strong selection during soybean domestication on GmSWEET10a. The selection of GmSWEET10a conferred simultaneous increases in soybean-seed size and oil content as well as a reduction in the protein content. The result was validated using both near-isogenic lines carrying substitution of haplotype chromosomal segments and transgenic soybeans. Moreover, GmSWEET10b was found to be functionally redundant with its homologue GmSWEET10a and to be undergoing selection in current breeding, leading the the elite allele GmSWEET10b, a potential target for present-day soybean breeding. Both GmSWEET10a and GmSWEET10b were shown to transport sucrose and hexose, contributing to sugar allocation from seed coat to embryo, which consequently determines oil and protein contents and seed size in soybean. We conclude that past selection of optimal GmSWEET10a alleles drove the initial domestication of multiple soybean-seed traits and that targeted selection of the elite allele GmSWEET10b may further improve the yield and seed quality of modern soybean cultivars. 相似文献
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Megan R. Gunnar Fran L. Porter Cynthia M. Wolf Joseph Rigatuso Mary C. Larson 《Child development》1995,66(1):1-13
To investigate the relations among popular measures of neonatal stress and their link to subsequent temperament, 50 full-term newborns from a normal care nursery were examined responding to a heelstick blood draw. Baseline and heelstick measures of behavioral state, heart period, vagal tone, and salivary cortisol were obtained. Recovery measures of behavioral and cardiac activity were also analyzed. Mothers completed Rothbart's Infant Behavior Questionnaire when their infants reached 6 months of age. Baseline vagal tone predicted cortisol in response to the heelstick, suggesting that baseline vagal tone reflects the infants' ability to react to stressors. Greater reactivity to the heelstick (more crying, shorter heart periods, lower vagal tone, and higher cortisol) was associated with lower scores on "Distress-to-Limitations" temperament at 6 months. This finding was consistent with the expectation that the capacity to react strongly to an aversive stimulus would reflect better neurobehavioral organization in the newborn. Recovery measures of cardiac activity approximated and were correlated with baseline measures indicating the strong self-righting properties of the healthy newborn. Finally, vagal tone and salivary cortisol measures were not significantly related, suggesting the importance of assessing both systems in studies of the ontogeny of stress-temperament relations. 相似文献
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This study examines how parent socioeconomic status (SES) directly and indirectly predicts children's school readiness through pathways of parental investment. Data come from direct assessments with preschool children and surveys with their primary caregivers in Ghana at the start of the 2015–2016 school year (N = 2,137; Mage = 5.2 years). Results revealed SES-related gaps in all parental investment characteristics and child school readiness skills. Preschool involvement served as the primary mediating mechanism in the path from SES to most school readiness skills, though it did not predict executive function. The number of books in the household was marginally positively predictive of early literacy, whereas at-home stimulation was negatively related to motor, literacy, and numeracy skills. 相似文献
6.
Tami Katzir YoungSuk Kim Maryanne Wolf Becky Kennedy Maureen Lovett Robin Morris 《Reading and writing》2006,19(8):845-872
The role of spelling recognition was examined in word reading skills and reading comprehension for dyslexic and nondyslexic children. Dyslexic and nondyslexic children were matched on their raw word reading proficiency. Relationships between spelling recognition and the following were examined for both groups of children: verbal ability, working memory, phonological measures, rapid naming, word reading, and reading comprehension. Children’s performance in spelling recognition was significantly associated with their skills in word reading and reading comprehension regardless of their reading disability status. Furthermore, spelling recognition contributed significant variance to reading comprehension for both dyslexic and nondyslexic children after the effects of phonological awareness, rapid naming, and word reading proficiency had been accounted for. The results support the role of spelling recognition in reading development for both groups of children and they are discussed using a componential reading fluency framework. 相似文献
7.
A. Zaher S. Li K. T. Wolf F. N. Pirmoradi O. Yassine L. Lin N. M. Khashab J. Kosel 《Biomicrofluidics》2015,9(5)
Implantable drug delivery systems can provide long-term reliability, controllability, and biocompatibility, and have been used in many applications, including cancer pain and non-malignant pain treatment. However, many of the available systems are limited to zero-order, inconsistent, or single burst event drug release. To address these limitations, we demonstrate prototypes of a remotely operated drug delivery device that offers controllability of drug release profiles, using osmotic pumping as a pressure source and magnetically triggered membranes as switchable on-demand valves. The membranes are made of either ethyl cellulose, or the proposed stronger cellulose acetate polymer, mixed with thermosensitive poly(N-isopropylacrylamide) hydrogel and superparamagnetic iron oxide particles. The prototype devices'' drug diffusion rates are on the order of 0.5–2 μg/h for higher release rate designs, and 12–40 ng/h for lower release rates, with maximum release ratios of 4.2 and 3.2, respectively. The devices exhibit increased drug delivery rates with higher osmotic pumping rates or with magnetically increased membrane porosity. Furthermore, by vapor deposition of a cyanoacrylate layer, a drastic reduction of the drug delivery rate from micrograms down to tens of nanograms per hour is achieved. By utilizing magnetic membranes as the valve-control mechanism, triggered remotely by means of induction heating, the demonstrated drug delivery devices benefit from having the power source external to the system, eliminating the need for a battery. These designs multiply the potential approaches towards increasing the on-demand controllability and customizability of drug delivery profiles in the expanding field of implantable drug delivery systems, with the future possibility of remotely controlling the pressure source. 相似文献
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Frances S. Grodzinsky Keith W. Miller Marty J. Wolf 《Ethics and Information Technology》2008,10(2-3):115-121
In their important paper “Autonomous Agents”, Floridi and Sanders use “levels of abstraction” to argue that computers are or may soon be moral agents. In this paper we use the same levels of abstraction to illuminate differences between human moral agents and computers. In their paper, Floridi and Sanders contributed definitions of autonomy, moral accountability and responsibility, but they have not explored deeply some essential questions that need to be answered by computer scientists who design artificial agents. One such question is, “Can an artificial agent that changes its own programming become so autonomous that the original designer is no longer responsible for the behavior of the artificial agent?” To explore this question, we distinguish between LoA1 (the user view) and LoA2 (the designer view) by exploring the concepts of unmodifiable, modifiable and fully modifiable tables that control artificial agents. We demonstrate that an agent with an unmodifiable table, when viewed at LoA2, distinguishes an artificial agent from a human one. This distinction supports our first counter-claim to Floridi and Sanders, namely, that such an agent is not a moral agent, and the designer bears full responsibility for its behavior. We also demonstrate that even if there is an artificial agent with a fully modifiable table capable of learning* and intentionality* that meets the conditions set by Floridi and Sanders for ascribing moral agency to an artificial agent, the designer retains strong moral responsibility. 相似文献
10.
To many who develop and use free software, the GNU General Public License represents an embodiment of the meaning of free
software. In this paper we examine the definition and meaning of free software in the context of three events surrounding
the GNU General Public License. We use a case involving the GPU software project to establish the importance of Freedom 0
in the meaning of free software. We analyze version 3 of the GNU General Public License and conclude that although a credible
case can be made that the added restrictions are consistent with the definition of free software, the case requires subtle
arguments. Strong arguments against the added restrictions are less subtle, and may therefore be more convincing to many users
and developers. We also analyze the Affero General Public License and conclude that it is inconsistent with the definition
of free software. 相似文献