scholarly journals Branch Occlusion and Discoloration under the Natural Pruning of Mytilaria laosensis

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 892
Author(s):  
Guoming Qin ◽  
Jian Hao ◽  
Jinchang Yang ◽  
Rongsheng Li ◽  
Guangtian Yin
Keyword(s):  
Radial Increment ◽  
High Quality ◽  
Mixed Effect ◽  
Branch Diameter ◽  
Occlusion Time ◽  
Wood Discoloration ◽  
Mixed Effect Models ◽  
Dead Branch ◽  
The Relationship ◽  
Mytilaria Laosensis

The production of knot-free and high-quality wood can be a vital issue in silviculture and forest management. In this study, knot properties, branch occlusion, and wood discoloration were investigated in an 11-year-old Mytilaria laosensis plantation in Guangxi, China, to examine the effectiveness of natural pruning in reducing knot-related defects. A total of 1513 occluded branches from 20 trees were sampled and dissected. Occluded branches were most common at heights of 2–6 m, and the mean diameter of the occluded branches gradually increased with height from the base to 6 m. Linear and generalized linear mixed-effect models were developed to reveal the relationship between branch occlusion and discoloration. The mortality of branches was highest in the third and fourth year and it took roughly three to six years to occlude. The mixed-models indicated that the branch occlusion time was positively correlated with the occluded branch diameter and dead branch stub length, and negatively correlated with the stem radial increment during branch occlusion. Branch discoloration was positively correlated with the occluded branch diameter and branch occlusion time, and was negatively correlated with the branch angle. The probability of wood discoloration also increased with the branch occlusion time. Our findings contribute to a better understanding of the spatiotemporal allocation and internal characteristics of occluded branches, and provide a reference for growing high-quality M. laosensis wood.

Comparative analysis of occluded branch characteristics for Fraxinus excelsior and Acer pseudoplatanus with natural and artificial pruning

2007 ◽  
Vol 37 (8) ◽  
pp. 1414-1426 ◽  
Author(s):  
Sebastian Hein ◽  
Heinrich Spiecker
Keyword(s):  
Mixed Models ◽  
Dominant Role ◽  
Fraxinus Excelsior ◽  
Radial Increment ◽  
Acer Pseudoplatanus ◽  
Data Set ◽  
Occlusion Time ◽  
Residual Variation ◽  
Dead Branch ◽  
Species Specific

The aim of this study was to develop models on branch characteristics for Fraxinus excelsior L. (common ash) and Acer pseudoplatanus L. (sycamore maple) based on 44 and 25 sample trees, respectively. A total of 635 ash and 334 maple branches were sampled. The data set on artificial pruning was pooled among the two species with a total of 71 branches from 16 trees. The material was used to predict (i) the time for a complete occlusion, (ii) the total radius of the occluded branch inside the trunk, (iii) the branch insertion angle, and (iv) the dead branch portion of the occluded branch. In addition, the effects of species and natural versus artificial pruning were assessed. Generalized hierarchical mixed models with univariate or multivariate approaches were used in this analysis. The diameter of the occluded branch and the stem radial increment played a dominant role as predictors. Artificial pruning led to a significant reduction in occlusion time and a shorter occluded branch radius. Only few species-specific differences were found. Simulations showed a reasonable overall behaviour of the models. The residual variation was tolerable for integrating the models into a growth simulation system.

The Impacts of Postdivorce Cohabitation and Relationship Duration on the Early Marital Climate of Remarriages

2021 ◽  
pp. 106648072110541
Author(s):  
J. Scott Crapo ◽  
Joshua J. Turner ◽  
Kay Bradford ◽  
Brian J. Higginbotham
Keyword(s):  
Marital Quality ◽  
Marital Instability ◽  
Mixed Effect ◽  
Negatively Associated ◽  
First Order ◽  
Relationship Duration ◽  
Mixed Effect Models ◽  
Climate Indicators ◽  
Using Data ◽  
The Relationship

Postdivorce cohabitation has become increasingly common, but research on the influence of cohabitation on the marital climate of remarriages is limited. Research on first-order marriages suggests that the length (or duration) of the relationship may account for some of the influence of cohabitation. However, there remains a need to understand the influence of cohabitation on the unique experiences of remarriages. Using data from 1,889 newly remarried individuals, we fit mixed-effect models to test the effect of cohabitation and relationship duration on the marital climate indicators of marital quality, marital instability, and remarital problems. Relationship duration, but not cohabitation, was negatively associated with marital quality. Cohabitation, but not relationship duration, was positively associated with marital instability and negatively associated with remarital problems. Results indicate that cohabitation may both benefit and harm remarital climates. This may explain, in part, the inconsistent findings in the literature and highlights the importance of studying remarriages as a unique population.

scholarly journals Cortical excitability signatures for the degree of sleepiness in human

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Chin-Hsuan Chia ◽  
Xin-Wei Tang ◽  
Yue Cao ◽  
Hua-Teng Cao ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Cortical Excitability ◽  
Underlying Mechanism ◽  
Self Report ◽  
Mixed Effect ◽  
Synaptic Homeostasis ◽  
Mixed Effect Models ◽  
Physiological Homeostasis ◽  
The Relationship ◽  
The Brain ◽  
Homeostasis Theory

Sleep is essential in maintaining physiological homeostasis in the brain. While the underlying mechanism is not fully understood, a 'synaptic homeostasis' theory has been proposed that synapses continue to strengthen during awake, and undergo downscaling during sleep. This theory predicts that brain excitability increases with sleepiness. Here, we collected transcranial magnetic stimulation (TMS) measurements in 38 subjects in a 34-hour program, and decoded the relationship between cortical excitability and self-report sleepiness using advanced statistical methods. By utilizing a combination of partial least squares (PLS) regression and mixed-effect models, we identified a robust pattern of excitability changes, which can quantitatively predict the degree of sleepiness. Moreover, we found that synaptic strengthen occurred in both excitatory and inhibitory connections after sleep deprivation. In sum, our study provides supportive evidence for the synaptic homeostasis theory in human sleep and clarifies the process of synaptic strength modulation during sleepiness.

scholarly journals The Longitudinal Assessment of Neuropsychiatric Symptoms in Mild Cognitive Impairment and Alzheimer’s disease and their Association with White Matter Hyperintensities in the National Alzheimer’s Coordinating Center’s Uniform Data Set

2019 ◽  
Author(s):  
Cassandra J. Anor ◽  
Mahsa Dadar ◽  
D. Louis Collins ◽  
M. Carmela Tartaglia
Keyword(s):  
White Matter ◽  
Significant Relationship ◽  
White Matter Hyperintensities ◽  
Neuropsychiatric Symptoms ◽  
Mixed Effect ◽  
Whole Brain ◽  
Mixed Effect Models ◽  
Severity Scores ◽  
The Relationship ◽  
Over Time

ABSTRACTIntroductionNeuropsychiatric symptoms (NPS) are common in all dementias, including those with Alzheimer’s disease (AD). NPS contribute to patients’ distress, caregiver burden, and can lead to institutionalization. White matter hyperintensities (WMH) are a common finding on MRI usually indicative of cerebrovascular disease and have been associated with certain NPS. The aim of this study was two-fold. Firstly, we assessed the relationship between WMH load and NPS severity in MCI due to AD (MCI-AD) and AD. Secondly, we assessed the ability of WMH to predict the development and progression of NPS in these participants. Data was obtained from the National Alzheimer’s Coordinating Center.MethodsWMH were obtained from baseline MRIs and quantified using an automated segmentation technique. NPS were measured using the Neuropsychiatric Inventory (NPI). Mixed effect models and correlations were used to determine the relationship between WMH load and NPS severity scores.ResultsCross-sectional analysis showed no significant association between NPS and WMH at baseline. Longitudinal mixed effect models, however, revealed a significant relationship between increase in NPI total scores and baseline WMH load (p=0.014). There was also a significant relationship between increase in irritability severity scores over time and baseline WMH load (p= 0.009). Trends were observed for a relationship between increase in agitation severity scores and baseline WMH load (p=0.058). No other NPS severity scores were significantly associated with baseline WMH load. The correlation plot analysis showed that baseline whole brain WMH predicted change in future NPI total scores (r=0.169, p=0.008). Baseline whole brain WMH also predicted change in future agitation severity scores (r= 0.165, p= 0.009). The temporal lobe WMH (r=0.169, p=0.008) and frontal lobe WMH (r=0.153, p=0.016) contributed most to this this change.ConclusionIrritability and agitation are common NPS and very distressful to patients and caregivers. Our findings of an increase in irritability severity over time as well as higher agitation severity scores at follow-up in participants with MCI-AD and AD with increased WMH loads have important implications for treatment, arguing for aggressive treatment of vascular risk factors in patients with MCI-AD and AD.

Compensatory Coping Through the Extension of Working Hours

2019 ◽  
Vol 63 (3) ◽  
pp. 115-128 ◽  
Author(s):  
Maie Stein ◽  
Sylvie Vincent-Höper ◽  
Nicole Deci ◽  
Sabine Gregersen ◽  
Albert Nienhaus
Keyword(s):  
Job Demands ◽  
Working Hours ◽  
Well Being ◽  
Leader Member Exchange ◽  
Workplace Health ◽  
High Quality ◽  
Data Analyses ◽  
Member Exchange ◽  
The Relationship ◽  
Advance Knowledge

Abstract. To advance knowledge of the mechanisms underlying the relationship between leadership and employees’ well-being, this study examines leaders’ effects on their employees’ compensatory coping efforts. Using an extension of the job demands–resources model, we propose that high-quality leader–member exchange (LMX) allows employees to cope with high job demands without increasing their effort expenditure through the extension of working hours. Data analyses ( N = 356) revealed that LMX buffers the effect of quantitative demands on the extension of working hours such that the indirect effect of quantitative demands on emotional exhaustion is only significant at low and average levels of LMX. This study indicates that integrating leadership with employees’ coping efforts into a unifying model contributes to understanding how leadership is related to employees’ well-being. The notion that leaders can affect their employees’ use of compensatory coping efforts that detract from well-being offers promising approaches to the promotion of workplace health.

scholarly journals An exploration of the relationship between recruitment communication and foraging in stingless bees

2021 ◽  
Author(s):  
Robbie I’Anson Price ◽  
Francisca Segers ◽  
Amelia Berger ◽  
Fabio S Nascimento ◽  
Christoph Grüter
Keyword(s):  
Stingless Bees ◽  
Sugar Content ◽  
Social Information ◽  
Food Resources ◽  
Food Sources ◽  
Foraging Strategies ◽  
High Quality ◽  
Recruitment Communication ◽  
Eusocial Bees ◽  
The Relationship

Abstract Social information is widely used in the animal kingdom and can be highly adaptive. In social insects, foragers can use social information to find food, avoid danger or choose a new nest site. Copying others allows individuals to obtain information without having to sample the environment. When foragers communicate information they will often only advertise high quality food sources, thereby filtering out less adaptive information. Stingless bees, a large pantropical group of highly eusocial bees, face intense inter- and intra-specific competition for limited resources, yet display disparate foraging strategies. Within the same environment there are species that communicate the location of food resources to nest-mates and species that do not. Our current understanding of why some species communicate foraging sites while others do not is limited. Studying freely foraging colonies of several co-existing stingless bee species in Brazil, we investigated if recruitment to specific food locations is linked to (1) the sugar content of forage, (2) the duration of foraging trips and (3) the variation in activity of a colony from one day to another and the variation in activity in a species over a day. We found that, contrary to our expectations, species with recruitment communication did not return with higher quality forage than species that do not recruit nestmates. Furthermore, foragers from recruiting species did not have shorter foraging trip durations than those from weakly-recruiting species. Given the intense inter- and intraspecific competition for resources in these environments, it may be that recruiting species favour food resources that can be monopolised by the colony rather than food sources that offer high-quality rewards.

scholarly journals A hierarchical bivariate meta-analysis of diagnostic test accuracy to provide direct comparisons of immunoassays vs. indirect immunofluorescence for initial screening of connective tissue diseases

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Michelle Elaine Orme ◽  
Carmen Andalucia ◽  
Sigrid Sjölander ◽  
Xavier Bossuyt
Keyword(s):  
Connective Tissue ◽  
Indirect Immunofluorescence ◽  
Meta Analysis ◽  
Connective Tissue Diseases ◽  
Test Accuracy ◽  
Initial Screening ◽  
Case Control Studies ◽  
Cross Sectional ◽  
Mixed Effect ◽  
Mixed Effect Models

AbstractObjectivesTo compare indirect immunofluorescence (IIF) for antinuclear antibodies (ANA) against immunoassays (IAs) as an initial screening test for connective tissue diseases (CTDs).MethodsA systematic literature review identified cross-sectional or case-control studies reporting test accuracy data for IIF and enzyme-linked immunosorbent assays (ELISA), fluorescence enzyme immunoassay (FEIA), chemiluminescent immunoassay (CLIA) or multiplex immunoassay (MIA). The meta-analysis used hierarchical, bivariate, mixed-effect models with random-effects by test.ResultsDirect comparisons of IIF with ELISA showed that both tests had good sensitivity (five studies, 2321 patients: ELISA: 90.3% [95% confidence interval (CI): 80.5%, 95.5%] vs. IIF at a cut-off of 1:80: 86.8% [95% CI: 81.8%, 90.6%]; p = 0.4) but low specificity, with considerable variance across assays (ELISA: 56.9% [95% CI: 40.9%, 71.5%] vs. IIF 1:80: 68.0% [95% CI: 39.5%, 87.4%]; p = 0.5). FEIA sensitivity was lower than IIF sensitivity (1:80: p = 0.005; 1:160: p = 0.051); however, FEIA specificity was higher (seven studies, n = 12,311, FEIA 93.6% [95% CI: 89.9%, 96.0%] vs. IIF 1:80 72.4% [95% CI: 62.2%, 80.7%]; p < 0.001; seven studies, n = 3251, FEIA 93.5% [95% CI: 91.1%, 95.3%] vs. IIF 1:160 81.1% [95% CI: 73.4%, 86.9%]; p < 0.0001). CLIA sensitivity was similar to IIF (1:80) with higher specificity (four studies, n = 1981: sensitivity 85.9% [95% CI: 64.7%, 95.3%]; p = 0.86; specificity 86.1% [95% CI: 78.3%, 91.4%]). More data are needed to make firm inferences for CLIA vs. IIF given the wide prediction region. There were too few studies for the meta-analysis of MIA vs. IIF (MIA sensitivity range 73.7%–86%; specificity 53%–91%).ConclusionsFEIA and CLIA have good specificity compared to IIF. A positive FEIA or CLIA test is useful to support the diagnosis of a CTD. A negative IIF test is useful to exclude a CTD.

scholarly journals Neurophysiological and behavioural effects of conventional and high definition tDCS

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fabio Masina ◽  
Giorgio Arcara ◽  
Eleonora Galletti ◽  
Isabella Cinque ◽  
Luciano Gamberini ◽  
...  
Keyword(s):  
Response Times ◽  
Power Reduction ◽  
Alpha Power ◽  
High Definition ◽  
Mixed Effect ◽  
State Dependency ◽  
Mixed Effect Models ◽  
Beta Power ◽  
Neurophysiological Data ◽  
Spectrum Density

AbstractHigh-definition transcranial direct current stimulation (HD-tDCS) seems to overcome a drawback of traditional bipolar tDCS: the wide-spread diffusion of the electric field. Nevertheless, most of the differences that characterise the two techniques are based on mathematical simulations and not on real, behavioural and neurophysiological, data. The study aims to compare a widespread tDCS montage (i.e., a Conventional bipolar montage with extracephalic return electrode) and HD-tDCS, investigating differences both at a behavioural level, in terms of dexterity performance, and a neurophysiological level, as modifications of alpha and beta power as measured with EEG. Thirty participants took part in three sessions, one for each montage: Conventional tDCS, HD-tDCS, and sham. In all the conditions, the anode was placed over C4, while the cathode/s placed according to the montage. At baseline, during, and after each stimulation condition, dexterity was assessed with a Finger Tapping Task. In addition, resting-state EEG was recorded at baseline and after the stimulation. Power spectrum density was calculated, selecting two frequency bands: alpha (8–12 Hz) and beta (18–22 Hz). Linear mixed effect models (LMMs) were used to analyse the modulation induced by tDCS. To evaluate differences among the montages and consider state-dependency phenomenon, the post-stimulation measurements were covariate-adjusted for baseline levels. We observed that HD-tDCS induced an alpha power reduction in participants with lower alpha at baseline. Conversely, Conventional tDCS induced a beta power reduction in participants with higher beta at baseline. Furthermore, data showed a trend towards a behavioural effect of HD-tDCS in participants with lower beta at baseline showing faster response times. Conventional and HD-tDCS distinctively modulated cortical activity. The study highlights the importance of considering state-dependency to determine the effects of tDCS on individuals.

scholarly journals Limited not lazy: a quasi-experimental secondary analysis of evidence quality evaluations by those who hold implausible beliefs

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Kristy A. Martire ◽  
Bethany Growns ◽  
Agnes S. Bali ◽  
Bronte Montgomery-Farrer ◽  
Stephanie Summersby ◽  
...  
Keyword(s):  
Secondary Analysis ◽  
Past Research ◽  
Linear Mixed Effect Model ◽  
High Quality ◽  
Mixed Effect ◽  
High Quality Evidence ◽  
Effect Model ◽  
Evidence Quality ◽  
Quasi Experimental ◽  
Quality Evidence

AbstractPast research suggests that an uncritical or ‘lazy’ style of evaluating evidence may play a role in the development and maintenance of implausible beliefs. We examine this possibility by using a quasi-experimental design to compare how low- and high-quality evidence is evaluated by those who do and do not endorse implausible claims. Seven studies conducted during 2019–2020 provided the data for this analysis (N = 746). Each of the seven primary studies presented participants with high- and/or low-quality evidence and measured implausible claim endorsement and evaluations of evidence persuasiveness (via credibility, value, and/or weight). A linear mixed-effect model was used to predict persuasiveness from the interaction between implausible claim endorsement and evidence quality. Our results showed that endorsers were significantly more persuaded by the evidence than non-endorsers, but both groups were significantly more persuaded by high-quality than low-quality evidence. The interaction between endorsement and evidence quality was not significant. These results suggest that the formation and maintenance of implausible beliefs by endorsers may result from less critical evidence evaluations rather than a failure to analyse. This is consistent with a limited rather than a lazy approach and suggests that interventions to develop analytical skill may be useful for minimising the effects of implausible claims.

scholarly journals Recombining Your Way Out of Trouble: The Genetic Architecture of Hybrid Fitness under Environmental Stress

2019 ◽  
Vol 37 (1) ◽  
pp. 167-182 ◽  
Author(s):  
Zebin Zhang ◽  
Devin P Bendixsen ◽  
Thijs Janzen ◽  
Arne W Nolte ◽  
Duncan Greig ◽  
...  
Keyword(s):  
Environmental Stress ◽  
Evolutionary Potential ◽  
Genetic Trait ◽  
Hybrid Fitness ◽  
Mixed Effect ◽  
Mixed Effect Models ◽  
Hybrid Genome ◽  
Chromosome Associations ◽  
Low Coverage ◽  
Negative Epistasis

Abstract Hybridization between species can either promote or impede adaptation. But we know very little about the genetic basis of hybrid fitness, especially in nondomesticated organisms, and when populations are facing environmental stress. We made genetically variable F2 hybrid populations from two divergent Saccharomyces yeast species. We exposed populations to ten toxins and sequenced the most resilient hybrids on low coverage using ddRADseq to investigate four aspects of their genomes: 1) hybridity, 2) interspecific heterozygosity, 3) epistasis (positive or negative associations between nonhomologous chromosomes), and 4) ploidy. We used linear mixed-effect models and simulations to measure to which extent hybrid genome composition was contingent on the environment. Genomes grown in different environments varied in every aspect of hybridness measured, revealing strong genotype–environment interactions. We also found selection against heterozygosity or directional selection for one of the parental alleles, with larger fitness of genomes carrying more homozygous allelic combinations in an otherwise hybrid genomic background. In addition, individual chromosomes and chromosomal interactions showed significant species biases and pervasive aneuploidies. Against our expectations, we observed multiple beneficial, opposite-species chromosome associations, confirmed by epistasis- and selection-free computer simulations, which is surprising given the large divergence of parental genomes (∼15%). Together, these results suggest that successful, stress-resilient hybrid genomes can be assembled from the best features of both parents without paying high costs of negative epistasis. This illustrates the importance of measuring genetic trait architecture in an environmental context when determining the evolutionary potential of genetically diverse hybrid populations.

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