RESUMO
Plants have evolved complex molecular, cellular and physiological mechanisms to respond to environmental stressors. Because of the inherent complexity of this response, genetic manipulation to substantially improve water deficit tolerance, particularly in agricultural crops, has been largely unsuccessful, as the improvements are frequently accompanied by slower growth and delayed reproduction. Here, we ectopically express two abiotic stress-responsive bZIP AREB/ABF transcription factor orthologs, Arabidopsis ABF3 and Gossypium hirsutum ABF2D, in G. hirsutum, to compare the effects of exogenous and endogenous AREB/ABF transgene overexpression on dehydration resilience. Our results show that ectopic expression of each of these orthologs increases dehydration resilience, although these increases are accompanied by slower growth. These phenotypic effects are proportional to the ectopic expression level in the GhABF2D transgenic plants, while the phenotypes of all of the AtABF3 transgenic plants are similar, largely independent of ectopic expression level, possibly indicating differential post-transcriptional regulation of these transgenes. Our results indicate that overexpression of exogenous and endogenous ABF homologs in G. hirsutum substantially increases drought resilience, primarily through stomatal regulation, negatively impacting transpiration and photosynthetic productivity.
Assuntos
Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Gossypium/fisiologia , Fatores de Transcrição/metabolismo , Proteínas de Arabidopsis/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Produtos Agrícolas , Secas , Expressão Ectópica do Gene , Gossypium/genética , Fenótipo , Fotossíntese , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estômatos de Plantas/genética , Estômatos de Plantas/fisiologia , Transpiração Vegetal/fisiologia , Plantas Geneticamente Modificadas , Estresse Fisiológico , Fatores de Transcrição/genéticaRESUMO
BACKGROUND: Hormonal contraception (HC) is widely used throughout the world and has been associated with venous thrombosis (VT) such as deep vein thrombosis, pulmonary emboli, and cerebral VT. OBJECTIVES: To provide a current comprehensive overview of the risk of objectively confirmed VT with HC in healthy women compared to nonusers. SEARCH METHODS: PubMed was searched from inception to April 2018 for eligible studies in the English language, with hand searching from past systematic reviews. SELECTION CRITERIA: We selected original research evaluating risk of objectively confirmed VT in healthy women taking oral or nonoral HC compared with nonusers. DATA COLLECTION: The primary outcome of interest was a fatal or nonfatal VT in users of HC compared to nonusers or past users. Studies with at least twenty events were eligible. Adjusted relative risks with 95 percent confidence intervals were reported. Three independent reviewers extracted data from selected studies. RESULTS: 1,962 publications were retrieved through the search strategy, with 15 publications included. Users of oral contraception with levonorgesterol had increased risk of VT by a range of 2.79-4.07, while other oral hormonal preparations increased risk by 4.0-48.6. Levonorgestrel intrauterine devices did not increase risk. Etonogestrel/ethinyl estradiol vaginal rings increased the risk of VT by 6.5. Norelgestromin/ethinyl estradiol patches increased risk of VT by 7.9. Etonogestrel subcutaneous implants by 1.4 and depot-medroxyprogesterone by 3.6. The risk of fatal VT was increased in women aged fifteen to twenty-four by 18.8-fold. CONCLUSION: Users of HC have a significant increased risk of VT compared to nonusers. Current risks would project at least 300-400 healthy young women dying yearly in the United States due to HC. Women should be informed of these risks and offered education in fertility-awareness-based methods with comparable efficacy for family planning. SUMMARY: HC is widely used throughout the world and has been associated with blood clots in the legs and lungs. We searched the literature and found the risks of currently used forms of birth control increased between three- and ninefold for blood clots for healthy women. The risks found would project 300-400 women dying from using HC each year in the United States.
RESUMO
Distractions and multitasking are generally detrimental to learning and memory. Nevertheless, people often study while listening to music, sitting in noisy coffee shops, or intermittently checking their e-mail. The current experiments examined how distractions and divided attention influence one's ability to selectively remember valuable information. Participants studied lists of words that ranged in value from 1 to 10 points while completing a digit-detection task, while listening to music, or without distractions. Though participants recalled fewer words following digit detection than in the other conditions, there were no significant differences between conditions in terms of selectively remembering the most valuable words. Similar results were obtained across a variety of divided-attention tasks that stressed attention and working memory to different degrees, which suggests that people may compensate for divided-attention costs by selectively attending to the most valuable items and that factors that worsen memory do not necessarily impair the ability to selectively remember important information.
Assuntos
Atenção/fisiologia , Função Executiva/fisiologia , Memória de Curto Prazo/fisiologia , Rememoração Mental/fisiologia , Aprendizagem Verbal/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
We examined the impact of repeated testing and repeated studying on long-term learning. In Experiment 1, we replicated Karpicke and Roediger's (2008) influential results showing that once information can be recalled, repeated testing on that information enhances learning, whereas restudying that information does not. We then examined whether the apparent ineffectiveness of restudying might be attributable to the spacing differences between items that were inherent in the between-subjects design employed by Karpicke and Roediger. When we controlled for these spacing differences by manipulating the various learning conditions within subjects in Experiment 2, we found that both repeated testing and restudying improved learning, and that learners' awareness of the relative mnemonic benefits of these strategies was enhanced. These findings contribute to understanding how two important factors in learning-test-induced retrieval processes and spacing-can interact, and they illustrate that such interactions can play out differently in between-subjects and within-subjects experimental designs.
Assuntos
Avaliação Educacional/métodos , Aprendizagem/fisiologia , Rememoração Mental , Retenção Psicológica , Estudantes/psicologia , Conscientização , Feminino , Humanos , Masculino , Prática Psicológica , Testes Psicológicos , Adulto JovemRESUMO
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 = 1498) 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 fully mediated by post-answer interest (i.e., interest in the questions' 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.
RESUMO
The current study examined younger and older adults' error detection accuracy, prediction calibration, and postdiction calibration on a proofreading task, to determine if age-related differences would be present in this type of common error detection task. 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. 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. 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 one's 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.
Assuntos
Envelhecimento/psicologia , Metacognição , Motivação , Leitura , Idoso , Análise de Variância , Atenção , Compreensão , Computadores , Feminino , Humanos , Julgamento , Masculino , Reconhecimento Visual de Modelos , Adulto JovemRESUMO
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 "stop" paradigm, the current research examined whether and how people choose to stop receiving new-possibly overwhelming-information 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 5 experiments, the authors 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. (PsycINFO Database Record
Assuntos
Tomada de Decisões , Aprendizagem , Rememoração Mental , Metacognição , Adulto , Feminino , Humanos , Masculino , Testes Psicológicos , Distribuição Aleatória , Recompensa , Adulto JovemRESUMO
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 "owed" 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.