scholarly journals You get what you pay for: reward-specific trade-offs among direct and ant-mediated defences in plants

2012 ◽  
Vol 8 (4) ◽  
pp. 628-630 ◽  
Author(s):  
Julia Koricheva ◽  
Gustavo Q. Romero
Keyword(s):  
Secondary Metabolites ◽  
Negative Correlation ◽  
Meta Analysis ◽  
Significant Negative Correlation ◽  
Extrafloral Nectaries ◽  
Plant Defences ◽  
Trade Offs ◽  
Species Comparisons ◽  
Plant Allocation ◽  
Indirect Defences

Plant defences against herbivores include direct defences such as secondary metabolites or physical structures (e.g. trichomes) as well as indirect defences mediated via mutualistic interactions with other organisms including ants. Production of both direct defences and rewards for mutualistic ants may be costly for a plant, and it has been suggested that trade-offs may exist between direct and ant-mediated defences. We have conducted a meta-analysis of 25 studies testing the above hypothesis and found a significant negative correlation between plant allocation to direct and ant-mediated defences. The strength of correlation was similar for across- and within-species comparisons, and for chemical and physical direct defences. However, trade-offs with direct defences were significant only in plants which offered to ants more costly rewards such as food bodies and/or domatia, but not in plants which attracted ants with relatively cheap extrafloral nectaries. Our results therefore support the hypothesis that plant investment in ant-mediated defences may reduce the requirement for direct chemical and physical defences, but only in plants which offer more costly rewards to their bodyguards.

The Relation Between Mathematics Anxiety and Mathematics Performance Among School-Aged Students: A Meta-Analysis

2019 ◽  
Vol 89 (3) ◽  
pp. 459-496 ◽  
Author(s):  
Jessica M. Namkung ◽  
Peng Peng ◽  
Xin Lin
Keyword(s):  
Negative Correlation ◽  
Mathematics Anxiety ◽  
Meta Analysis ◽  
Significant Negative Correlation ◽  
Mathematics Performance ◽  
Mathematical Tasks ◽  
Final Exam ◽  
And Mathematics ◽  
Underlying Mechanisms ◽  
Student Grades

The purpose of this meta-analysis was to examine the relation between mathematics anxiety (MA) and mathematics performance among school-aged students, and to identify potential moderators and underlying mechanisms of such relation, including grade level, temporal relations, difficulty of mathematical tasks, dimensions of MA measures, effects on student grades, and working memory. A meta-analysis of 131 studies with 478 effect sizes was conducted. The results indicated that a significant negative correlation exist between MA and mathematics performance, r = −.34. Moderation analyses indicated that dimensions of MA, difficulty of mathematical tasks, and effects on student grades differentially affected the relation between MA and mathematics performance. MA assessed with both cognitive and affective dimensions showed a stronger negative correlation with mathematics performance compared to MA assessed with either an affective dimension only or mixed/unspecified dimensions. Advanced mathematical tasks that require multistep processes showed a stronger negative correlation to MA compared to foundational mathematical tasks. Mathematics measures that affected/reflected student grades (e.g., final exam, students’ course grade, GPA) had a stronger negative correlation to MA than did other measures of mathematics performance that did not affect student grades (e.g., mathematics measures administered as part of research). Theoretical and practical implications of the findings are discussed.

Complexity trade-offs do not prove the equal complexity hypothesis

2014 ◽  
Vol 50 (2) ◽  
Author(s):  
Gertraud Fenk-Oczlon ◽  
August Fenk
Keyword(s):  
Negative Correlation ◽  
Null Hypothesis ◽  
Quantitative Methods ◽  
Significant Negative Correlation ◽  
Second Step ◽  
Trade Offs ◽  
Monosyllabic Words ◽  
Complexity Hypothesis ◽  
Positive Correlations

AbstractComplexity trade-offs are often considered as evidence for the hypothesis that all languages are equally complex; simplicity in one component of grammar is balanced by complexity in another. According to Shosted (2006), this "negative correlation hypothesis", as he calls it, was never validated using quantitative methods. The present paper recalls, in a first step, our previously found significant negative cross-linguistic correlations between syllable complexity and number of syllables per clause and per word, as well as an almost significant negative correlation between syllable complexity and number of morphological cases. All these correlations indicate complexity trade-offs between subsystems of language, as do the positive correlations found between syllable complexity, number of syllable types, and number of monosyllabic words. In a second step we argue against the view of such complexity trade-offs as proof of the equal complexity hypothesis. This hypothesis is hardly testable for several reasons: As long as it is impossible to quantify the overall complexity of a single language, it is also impossible to compare different languages with respect to that quantity. Secondly, it could – because of its character as a null hypothesis – never be corroborated for principal reasons.

A meta-analysis of the relationship between parenting style and Internet addiction among mainland Chinese teenagers

2018 ◽  
Vol 46 (9) ◽  
pp. 1475-1487 ◽  
Author(s):  
Shunyu Li ◽  
Hao Lei ◽  
Lan Tian
Keyword(s):  
Parenting Style ◽  
Negative Correlation ◽  
Internet Addiction ◽  
Meta Analysis ◽  
Significant Negative Correlation ◽  
School Level ◽  
Mainland Chinese ◽  
Positive Indicators ◽  
The Relationship ◽  
Practical Implications

We performed a meta-analysis of 79 studies to explore the relationship between positive and negative indicators of parenting style and Internet addiction among 44,650 mainland Chinese teenagers. Results showed that positive indicators of parenting style had a significant negative correlation with teenagers' Internet addiction and that the correlation was moderated by region and school level. Negative indicators of parenting style were significantly and positively correlated with teenagers' Internet addiction and the correlation was also moderated by region and school level. Theoretical and practical implications of the findings are discussed.

Thrombin generation in paediatric patients with congenital heart disease

2008 ◽  
Vol 28 (S 01) ◽  
pp. S61-S66 ◽  
Author(s):  
G. Cvirn ◽  
A. Rosenkranz ◽  
B. Leschnik ◽  
W. Raith ◽  
W. Muntean ◽  
...  
Keyword(s):  
Congenital Heart Disease ◽  
Heart Disease ◽  
Negative Correlation ◽  
Congenital Heart ◽  
Thrombin Generation ◽  
Significant Negative Correlation ◽  
Peak Height ◽  
Global Test ◽  
Paediatric Patients ◽  
Age Range

SummaryThrombin generation was studied in paediatric patients with congenital heart disease (CHD) undergoing cardiac surgery using the calibrated automated thrombography (CAT) in terms of the lag time until the onset of thrombin formation, time to thrombin peak maximum (TTP), endogenous thrombin potential (ETP), and thrombin peak height. The suitability to determine the coagulation status of these patients was investigated. Patients, material, methods: CAT data of 40 patients with CHD (age range from newborn to 18 years) were compared to data using standard coagulation parameters such as prothrombin (FII), antithrombin (AT), tissue factor pathway inhibitor (TFPI), prothrombin fragment 1.2 (F 1.2), thrombin-antithrombin (TAT), activated partial thromboplastin time (aPTT), and prothrombin time (PT). Results: A significant positive correlation was seen between ETP and FII (p < 0.01; r = 0.369), as well as between peak height and F II (p < 0.01; r = 0.483). A significant negative correlation was seen between ETP and TFPI values (p < 0.05; r = –0.225) while no significant correlation was seen between peak height and TFPI. A significant negative correlation was seen between F 1.2 generation and ETP (p < 0.05; r = –0.254) and between F 1.2 generation and peak height (p < 0.05; r = –0.236). No correlation was seen between AT and ETP or peak. Conclusions: CAT is a good global test reflecting procoagulatory and inhibitory factors of the haemostatic system in paediatric patients with CHD.

Negative Correlation Between Serum Levels of Homocysteine and Apolipoprotein M

2019 ◽  
Vol 19 (2) ◽  
pp. 120-126
Author(s):  
J. Wei ◽  
Y. Yu ◽  
Y. Feng ◽  
J. Zhang ◽  
Q. Jiang ◽  
...  
Keyword(s):  
Negative Correlation ◽  
Hepg2 Cells ◽  
Serum Levels ◽  
Significant Negative Correlation ◽  
Mrna Levels ◽  
Rt Pcr ◽  
Apolipoprotein M ◽  
Protein Mass ◽  
Protein Levels ◽  
Phosphoinositide 3 Kinase

Background: Homocysteine (Hcy) has been suggested as an independent risk factor for atherosclerosis. Apolipoprotein M (apoM) is a constituent of the HDL particles. The goal of this study was to examine the serum levels of homocysteine and apoM and to determine whether homocysteine influences apoM synthesis. Methods: Serum levels of apoM and Hcy in 17 hyperhomocysteinemia (HHcy) patients and 19 controls were measured and their correlations were analyzed. Different concentrations of homocysteine (Hcy) and LY294002, a specific phosphoinositide 3- kinase (PI3K) inhibitor, were used to treat HepG2 cells. The mRNA levels were determined by RT-PCR and the apoM protein mass was measured by western blot. Results: We found that decreased serum apoM levels corresponded with serum HDL levels in HHcy patients, while the serum apoM levels showed a statistically significant negative correlation with the serum Hcy levels. Moreover, apoM mRNA and protein levels were significantly decreased after the administration of Hcy in HepG2 cells, and this effect could be abolished by addition of LY294002. Conclusions: resent study demonstrates that Hcy downregulates the expression of apoM by mechanisms involving the PI3K signal pathway.

scholarly journals Daytime nap and nighttime breastfeeding are associated with toddlers’ nighttime sleep

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Machiko Nakagawa ◽  
Hidenobu Ohta ◽  
Rinshu Shimabukuro ◽  
Yoko Asaka ◽  
Takayo Nakazawa ◽  
...  
Keyword(s):  
Sleep Duration ◽  
Negative Correlation ◽  
Significant Negative Correlation ◽  
Sleep Diary ◽  
Daytime Nap ◽  
Nighttime Sleep

AbstractThe purpose of the present study is to examine the association between toddlers' sleep arrangements and their nighttime sleep duration and other sleep variables. For this investigation, we performed a study in which child activity and sleep levels were recorded using actigraphy. The parents of 1.5-year-old toddlers (n = 106) were asked to attach an actigraphy unit to their child’s waist with an adjustable elastic belt and complete a sleep diary for 7 consecutive days. Questionnaires were used to assess the sleep arrangements of the toddlers. There was a significant negative correlation between nap duration and nighttime sleep duration, suggesting that longer nap sleep induces shorter nighttime sleep duration. Among the sleep arrangements, such as nighttime breastfeeding or co-sleeping, only nighttime breastfeeding predicted shorter nighttime sleep duration. Our findings indicate that shorter naps induce a longer nighttime sleep in 1.5-year-old toddlers while nighttime breastfeeding decreases their nighttime sleep duration.

scholarly journals Adult body growth and reproductive investment vary markedly within and across Atlantic and Pacific herring: a meta-analysis and review of 26 stocks

2021 ◽  
Author(s):  
Thassya C. dos Santos Schmidt ◽  
Doug E. Hay ◽  
Svein Sundby ◽  
Jennifer A. Devine ◽  
Guðmundur J. Óskarsson ◽  
...  
Keyword(s):  
Egg Size ◽  
Meta Analysis ◽  
Reproductive Investment ◽  
Body Growth ◽  
Clupea Harengus ◽  
Pacific Herring ◽  
Atlantic Herring ◽  
Additional Information ◽  
Trade Offs ◽  
Investment In Reproduction

AbstractLife-history traits of Pacific (Clupea pallasii) and Atlantic (Clupea harengus) herring, comprising both local and oceanic stocks subdivided into summer-autumn and spring spawners, were extensively reviewed. The main parameters investigated were body growth, condition, and reproductive investment. Body size of Pacific herring increased with increasing latitude. This pattern was inconsistent for Atlantic herring. Pacific and local Norwegian herring showed comparable body conditions, whereas oceanic Atlantic herring generally appeared stouter. Among Atlantic herring, summer and autumn spawners produced many small eggs compared to spring spawners, which had fewer but larger eggs—findings agreeing with statements given several decades ago. The 26 herring stocks we analysed, when combined across distant waters, showed clear evidence of a trade-off between fecundity and egg size. The size-specific individual variation, often ignored, was substantial. Additional information on biometrics clarified that oceanic stocks were generally larger and had longer life spans than local herring stocks, probably related to their longer feeding migrations. Body condition was only weakly, positively related to assumingly in situ annual temperatures (0–30 m depth). Contrarily, body growth (cm × y−1), taken as an integrator of ambient environmental conditions, closely reflected the extent of investment in reproduction. Overall, Pacific and local Norwegian herring tended to cluster based on morphometric and reproductive features, whereas oceanic Atlantic herring clustered separately. Our work underlines that herring stocks are uniquely adapted to their habitats in terms of trade-offs between fecundity and egg size whereas reproductive investment mimics the productivity of the water in question.

scholarly journals Correlates of SARS-CoV-2 Variants on Deaths, Case Incidence and Case Fatality Ratio among the Continents for the Period of 1 December 2020 to 15 March 2021

Genes ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 1061
Author(s):  
Wajdy J. Al-Awaida ◽  
Baker Jawabrah Al Hourani ◽  
Samer Swedan ◽  
Refat Nimer ◽  
Foad Alzoughool ◽  
...  
Keyword(s):  
Negative Correlation ◽  
Significant Positive Correlation ◽  
Vaccine Development ◽  
Case Fatality ◽  
Significant Negative Correlation ◽  
Reference Sequence ◽  
Genome Sequences ◽  
Positive Correlation ◽  
Case Fatality Ratio ◽  
Epidemiological Surveys

The outbreak of coronavirus disease 2019 (COVID-19), by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has quickly developed into a worldwide pandemic. Mutations in the SARS-CoV-2 genome may affect various aspects of the disease including fatality ratio. In this study, 553,518 SARS-CoV-2 genome sequences isolated from patients from continents for the period 1 December 2020 to 15 March 2021 were comprehensively analyzed and a total of 82 mutations were identified concerning the reference sequence. In addition, associations between the mutations and the case fatality ratio (CFR), cases per million and deaths per million, were examined. The mutations having the highest frequencies among different continents were Spike_D614G and NSP12_P323L. Among the identified mutations, NSP2_T153M, NSP14_I42V and Spike_L18F mutations showed a positive correlation to CFR. While the NSP13_Y541C, NSP3_T73I and NSP3_Q180H mutations demonstrated a negative correlation to CFR. The Spike_D614G and NSP12_P323L mutations showed a positive correlation to deaths per million. The NSP3_T1198K, NS8_L84S and NSP12_A97V mutations showed a significant negative correlation to deaths per million. The NSP12_P323L and Spike_D614G mutations showed a positive correlation to the number of cases per million. In contrast, NS8_L84S and NSP12_A97V mutations showed a negative correlation to the number of cases per million. In addition, among the identified clades, none showed a significant correlation to CFR. The G, GR, GV, S clades showed a significant positive correlation to deaths per million. The GR and S clades showed a positive correlation to number of cases per million. The clades having the highest frequencies among continents were G, followed by GH and GR. These findings should be taken into consideration during epidemiological surveys of the virus and vaccine development.

387 The moderating effect of emotion regulation strategies in the relationship between insomnia severity and bedtime procrastination

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A153-A154
Author(s):  
Huisu Jeon ◽  
Sonhye Jeoung ◽  
Goeun Kim ◽  
Hyeyoung An ◽  
Hyojin Nam ◽  
...  
Keyword(s):  
Negative Correlation ◽  
Emotional Regulation ◽  
Significant Negative Correlation ◽  
Moderating Effect ◽  
Active Regulation ◽  
Support Seeking ◽  
Regulation Strategies ◽  
Bedtime Procrastination ◽  
The Relationship ◽  
Insomnia Severity

Abstract Introduction Bedtime Procrastination (BP) is defined as the behavior of going to bed later than intended, despite the absence of external factors. Bedtime procrastination is also prevalent among insomnia patients, and is associated with various sleep problems. Recent studies suggest emotional regulation as a mechanism of the procrastination behavior that is the conceptual foundation of bedtime procrastination. Emotional regulation difficulties are also associated with insomnia, but there is still a lack of research on the relationship between insomnia, emotional regulation strategies and bedtime procrastination. Thus, the study assumed that severity of insomnia would affect bedtime procrastination, and examined the moderating effect of the emotional regulation strategies in this relationship. Methods This study was conducted in 376 adults (mean age 23.73 ±2.14 years, 84.6% females). Participants were asked to answer Bedtime procrastination scale (BPS), an emotional regulation strategy checklist, and the Insomnia severity scale (ISI). Results As a result, a significant positive correlation was found between insomnia severity and bedtime procrastination (r=.286, p&lt;.01), and avoidant/distractive regulation style (r=.101, p&lt;.05). active regulation style (r=-.172, p&lt;.01) and support seeking regulation style (r=-.102, p&lt;.01) showed a significant negative correlation with the severity of insomnia. Bedtime procrastination behavior showed significant negative correlation only with active regulation style (r=-.151, p&lt;.01). Support seeking regulation style moderated the relationship between insomnia and bedtime procrastination behavior (B=.0165, 95%, CI=.0014, .0316). The interaction effect between insomnia and support seeking regulation style was also significant (∆R^2=.0112, p&lt;.05), indicating that the effect of insomnia on bedtime procrastination depends on the level of use of the support seeking regulation style. Conclusion These findings suggest that the level of support seeking regulation style is meaningful in terms of how insomnia affects bedtime procrastination. Support (if any) This work was supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea(NRF-2018S1A5A8026807)

Why Do Firms Participate in Voluntary Environmental Programs? A Meta-Analysis of the Role of Institutions, Resources, and Program Stringency

2021 ◽  
pp. 108602662199006
Author(s):  
Peter Tashman ◽  
Svetlana Flankova ◽  
Marc van Essen ◽  
Valentina Marano
Keyword(s):  
Quality Management ◽  
Prior Experience ◽  
Meta Analysis ◽  
Institutional Pressures ◽  
Environmental Programs ◽  
Voluntary Environmental Programs ◽  
Management Standards ◽  
Trade Offs ◽  
The Impact

We meta-analyze research on why firms join voluntary environmental programs (VEPs) to assess the impact of program stringency, or the extent to which they have rigorous, enforceable standards on these decisions. Stringency creates trade-offs for firms by affecting programs’ effectiveness, legitimacy, and adoption costs. Most research considers singular programs and lacks cross program variation needed to analyze program stringency’s impact. Our meta-analysis addresses this by sampling 127 studies and 23 VEPs. We begin by identifying common institutional and resource-based drivers of participation in the literature, and then analyze how program stringency moderates their impacts. Our results suggest that strictly governed VEPs encourage participation among highly visible and profitable firms, and discourage it when informal institutional pressures are higher, and firms have prior experience with other VEPs or quality management standards. We demonstrate that VEP stringency has nuanced effects on firm participation based on the institutional and resource-based factors facing them.

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