Summary
Understanding species differences in plant functional traits has been critical in developing a mechanistic understanding of terrestrial ecological processes. Greater attention is now being ...placed on understanding the extent, causes and consequences of intraspecific trait variation (ITV).
ITV is especially important in governing ecological processes in cropping systems, where only a small number of species or genotypes exist in high abundances. However, it remains unclear if key principles of trait‐based ecology – namely the leaf economics spectrum (LES) – also describe intraspecific variation in crop functional biology. There also remains a need to understand whether ITV within crops is random, or structured across environmental, management‐related or biological levels of organization in agroecosystems.
We employed a nested design field survey to evaluate ITV in leaf traits in coffee (Coffea arabica), one of the world's most widespread tropical crops. We evaluated ITV in eight physiological, morphological and chemical leaf traits, across five nested categorical levels (sites, management systems, spatial location, plant identity, branch identity). We compared patterns of LES trait covariation in coffee, to interspecific patterns observed across over 700 wild plant species.
Patterns of bivariate and multivariate ITV in coffee were broadly consistent with, but considerably weaker than, interspecific patterns associated with the LES, indicating that crops may systematically diverge from global patterns of trait trade‐offs observed in wild plants.
Physiological traits varied most widely (coefficient of variation (cv) 42–107%), followed by morphological traits (cv = 15–38%) and chemical traits (cv = 3–11%). Physiological ITV was best explained by the site in which a coffee plant was growing (17–55% explained), while ITV for chemical traits was best explained by management treatments within sites (25–36%); morphological ITV was higher even at the individual tree level or branch level and remained largely unexplained.
Our results support the hypothesis that artificial selection and high‐resource agricultural environments lead crops to systematically deviate from patterns of leaf trait covariation observed across wild plants species. Coupled with an understanding of how different traits vary systematically across multiple levels of biological organization, these findings help integrate ITV into future analyses of agroecosystem structure and function.
A lay summary is available for this article.
Lay Summary
•Few studies have examined leaf trait variation in important tree-crop species.•Leaf traits varied widely across coffee plants under a range of shade tree composition.•Coffee leaf traits covaried in ...patterns consistent with the Leaf Economics Spectrum.•Trait syndromes were related to light transmission and estimates of reproductive output.•We contribute a trait-based approach to evaluate plant response to agroforestry management.
The leaf economics spectrum (LES) refers to a suite of correlated leaf-level physiological, morphological, and chemical traits that can be used to describe life-history strategy among plant species. Documenting LES trait variation across environmental gradients has been important for understanding natural plant community dynamics in response to environmental change. However few studies have examined how LES traits covary within crops, or how the LES is correlated with farm-level management practices or goals, especially for important tree-crops such as coffee. We analyzed within-species variation in eight leaf traits in 60 Coffea arabica plants, across four management treatments differing in shade-tree species composition, to test (i) if hypothesized LES patterns also describe within-species trait variation, and (ii) if LES traits vary in response to management regimes, or are correlated with reproductive output. Leaf traits varied widely across coffee plants with photosynthetic rates (Amass) and leaf area showing especially high variation. In bivariate and multivariate analyses, coffee leaf traits covaried in patterns consistent with the LES, suggesting shifts between leaf-level resource acquisition and conservation traits among plants may also underpin coffee responses to agroforestry management. The position of a coffee plant along the LES (as described by a principal component analysis score) was best explained by light availability, but did not vary systematically with shade tree composition. LES traits were weakly but significantly related to plant-level reproductive output: coffee plants associated with lower Amass and leaf N values, and higher leaf mass per area were associated with greater reproductive output. In showing that the LES describes resource capture and/or conservation strategies among coffee plants, our study represents a novel adoption of the LES to address applied questions in managed systems. Since within species differences in leaf traits partially explain differences in coffee yield, we also suggest that trait-based research in agroecology can contribute to an applied and comprehensive understanding of crop functional biology, and ultimately, agroecosystem structure and function.
Highlights • GABAergic blockade into the MT caused panic-like defensive behavior. • AEA injections in the SNpr decreased of defensive behavior of mice confronted with snake. • AEA into the SNpr ...caused a reduction of panic-like behavior of mice treated with GABAergic antagonist in the MT. • CB1 RS seems to be located mainly in presynaptic terminals of the striatonigral pathway. • eCBs mechanisms modulate the activity of nigrotectal GABAergic pathways decreasing the activity of striatonigral links.
The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes.
Cattle lameness remains a significant concern, causing ...economic losses and compromising animal welfare. Claw horn lesions have been identified as a major cause of lameness in dairy cows, but their correlation with high-energy diets and ruminal acidosis remains unclear. Hence, the primary objective of this study was to assess the effects of a high-starch diet and a conventional diet on the rumen environment, acute-phase proteins, and metabolic alterations, with a particular focus on insulin resistance and the consequent implications for the histology of the hooves in Holstein steers. A total of 16 animals were divided into the high-starch (HS; 37% starch) and conventional (CON; 16.8% starch) groups. Glucose tolerance tests (GTT), blood analyses, rumen fluid analyses, and histological evaluations of the hoof tissue were conducted over a 102-d experimental period. The HS group showed a lower ruminal pH than the CON group, and with values indicating SARA. The plasma glucose and IGF-1 concentrations were higher in the HS group, suggesting an anabolic state. Both groups exhibited an increase in the insulin area under the curve (AUC) after the GTT on d 102. Histological analysis of the hooves showed a reduction in the length and width of the epidermal lamella in both groups. We found a significant negative correlation between the insulin AUC and the length and width of the epidermal lamella. Because both groups were similarly affected, the hypothesis that histological alterations were caused by the experimental diets still needs confirmation. Additionally, the development of SARA was not essential for the observed histological changes in the hoof. Further studies are warranted to thoroughly investigate the role of insulin and IGF-1 imbalances in claw health.
•Coffee rust monitoring is the most important predictor for future incidences.•Temperature is a determining driver in days 9 to 6 and 4 to 1 before the prediction.•The amount of rain determines the ...uredospore dispersal or washing conditions.•The model mean absolute error expected is 6.94% of incidence after feature selection.
Coffee Leaf Rust (CLR) is a disease that leads to considerable losses in the worldwide coffee industry; as those that have been reported recently in Colombia and Central America. The early detection of favorable conditions for epidemics could be used to improve decision making for the coffee grower and thus reduce the losses due to the disease. Researchers tried to predict the occurrence of the disease earlier through statistical and machine learning models from crop properties, disease indicators and weather conditions. These studies considered the impact of weather variables in a common period for all. Assuming that the dynamics of weather that most impact the development of the disease occur in the same time periods is simplistic. We propose an approach to discover the time period (window) for each weather variables and crop related features that most explain a future observed CLR incidence, in order to obtain a prediction model through machine learning. The selection of the variables more related with coffee rust incidence and rejection of the features with no significant contribution of information in machine learning tasks were approached from Feature Selection methods (Filter, Wrapper, Embedded). In this way, a CLR incidence prediction model based on the features with the greatest impact on the development of the disease was obtained. Moreover, the use of SHapley Additive exPlanations allowed us to identify the impact of features in the model prediction. The monitoring of coffee rust incidence is the most important predictor, since it provides information about current inoculum and this determines how much can the incidence grow or decrease. Temperature is a determining driver for germination and penetration phases in days 9 to 6 and 4 to 1 before the date of prediction. Additionally, the amount of rain determines whether uredospore dispersal or washing conditions occurred. The mean absolute error expected in the model is 6.94% of incidence, trained with XGBoost algorithm and the dataset reduced by Embedded method. The estimation of the disease incidence 28 days later can be used to improve decision making in control and nutrition practices.
Resistance training has a positive impact on functional capacity and muscle mass in the elderly. However, due to physical limitations or a simple aversion against regular exercise, a majority of the ...elderly do not reach the recommended exercise doses. This led us to evaluate the effect of whole-body electromyostimulation (WB-EMS), a novel, time-efficient, and smooth training technology on physical function, fat-free mass, strength, falls-efficacy, and social participation of the elderly.
The present study is a randomized, parallel group clinical trial approved by the Ethics Committee of our Institution. Sixty-six volunteers (age ≥ 60 years) will be recruited from the geriatric outpatient department in a tertiary hospital and primary care units and randomized into two groups: WB-EMS group or active control group (aCG). The WB-EMS or aCG protocol will consist of 16 sessions for 8 consecutive weeks, twice per week. The primary outcomes will be maximal isometric knee extension (IKE), functional lower extremity strength, fat-free mass, gait speed, and risk of falls measured before and after intervention. The secondary outcomes will be social participation and falls-efficacy assessed before and after the intervention and at three and six months of follow-up. Participant's satisfaction with and awareness of electrical stimulation therapy will also be assessed immediately after the 8-week intervention.
Patients receiving WB-EMS exercises are believed to have better outcomes than those receiving conventional, more time-consuming resistance exercises. Hence, innovative, time-efficient, joint-friendly, and highly individualized exercise technologies (such as WB-EMS) may be a good choice for the elderly with time constraints, physical limitations, or little enthusiasm, who are exercising less than the recommended amounts for impact on muscle mass, strength, and function.
The load in resistance training is considered to be a critical variable for neuromuscular adaptations. Therefore, it is important to assess the effects of applying different loads on the development ...of maximal strength and muscular hypertrophy. The aim of this study was to systematically review the literature and compare the effects of resistance training that was performed with low loads versus moderate and high loads in untrained and trained healthy adult males on the development of maximal strength and muscle hypertrophy during randomized experimental designs. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (2021) were followed with the eligibility criteria defined according to participants, interventions, comparators, outcomes, and study design (PICOS): (P) healthy males between 18 and 40 years old, (I) interventions performed with low loads, (C) interventions performed with moderate or high loads, (O) development of maximal strength and muscle hypertrophy, and (S) randomized experimental studies with between- or within-subject parallel designs. The literature search strategy was performed in three electronic databases (Embase, PubMed, and Web of Science) on 22 August 2021. Results: Twenty-three studies with a total of 563 participants (80.6% untrained and 19.4% trained) were selected. The studies included both relative and absolute loads. All studies were classified as being moderate-to-high methodological quality, although only two studies had a score higher than six points. The main findings indicated that the load magnitude that was used during resistance training influenced the dynamic strength and isometric strength gains. In general, comparisons between the groups (i.e., low, moderate, and high loads) showed higher gains in 1RM and maximal voluntary isometric contraction when moderate and high loads were used. In contrast, regarding muscle hypertrophy, most studies showed that when resistance training was performed to muscle failure, the load used had less influence on muscle hypertrophy. The current literature shows that gains in maximal strength are more pronounced with high and moderate loads compared to low loads in healthy adult male populations. However, for muscle hypertrophy, studies indicate that a wide spectrum of loads (i.e., 30 to 90% 1RM) may be used for healthy adult male populations.
This paper proposes an improved version of a recently proposed modified simulated annealing algorithm (MSAA) named as an improved MSAA (I-MSAA) to tackle the size optimization of truss structures ...with frequency constraint. This kind of problem is problematic because its feasible region is non-convex while the boundaries are highly non-linear. The main motivation is to improve the exploitative behavior of MSAA, taking concept from water wave optimization metaheuristic (WWO). An interesting concept of WWO is its
breaking
operation. Thirty functions extracted from the CEC2014 test suite and four benchmark truss optimization problems with frequency constraints are explored for the validity of the proposed algorithm. Numerical results indicate that I-MSAA is more reliable, stable and efficient than those found by other existing metaheuristics in the literature.
Falls determine huge epidemiological, clinical, and economic burden in the older population worldwide, presenting high odds of severe disability. The present study aimed to estimate the prevalence of ...falls and associated factors in older Brazilians using a systematic review with meta-analysis. Searches were performed in SciELO, PubMed, LILACS, Web of Science, Scopus and PsycINFO databases with no date or language restrictions. Studies on community-dwelling older persons aged ≥ 60 years from both sexes and with a sample size of ≥ 300 participants included. Exclusion criteria were studies conducted specifically for older adults diagnosed with chronic disabling diseases that predispose them to falls. Risk of bias of included studies was assessed using a critical appraisal tool focusing on prevalence designs. A random-effects meta-analysis was used to pool the prevalence of falls across studies. Exploratory analysis was conducted examining subgroup estimates, prevalence ratios and meta-regression. Thirty-seven studies involving 58,597 participants were included. Twelve-month prevalence of falls was 27% (95%CI: 24.3-30.0), with significantly higher estimates in female than male (PR = 1.57; 95%CI: 1.32-1.86), in age group ≥ 80 years than age group 60-69 years (PR = 1.46; 95%CI: 1.15-1.84), and in participants from the Central region than participants from the South region (PR = 1.36; 95%CI: 1.10-1.69) of Brazil. Risk of bias scores did not impact heterogeneity in the 12-month meta-analysis. These estimates strongly support evidence-based public interventions to prevent falls in older Brazilians, especially in women and the oldest-old population.
Research has demonstrated that intraspecific functional trait variation underpins plant responses to environmental variability. However, few studies have evaluated how trait variation shifts in ...response to plant pathogens, even though pathogens are a major driver of plant demography and diversity, and despite evidence of plants expressing distinct strategies in response to pathogen pressures. Understanding trait-pathogen relationships can provide a more realistic understanding of global patterns of functional trait variation. We examined leaf intraspecific trait variability (ITV) in response to foliar disease severity, using Coffea arabica cv. Caturra as a model species. We quantified coffee leaf rust (CLR) severity-a fungal disease prominent in coffee systems-and measured key coffee leaf functional traits under contrasting, but widespread, management conditions in an agroforestry system. We found that coffee plants express significant ITV, which is largely related to shade tree treatment and leaf position within coffee canopy strata. Yet within a single plant canopy stratum, CLR severity increased with increasing resource conserving trait values. However, coffee leaves with visible signs of disease expressed overall greater resource acquiring trait values, as compared to plants without visible signs of disease. We provide among the first evidence that leaf traits are correlated with foliar disease severity in coffee, and that functional trait relationships and syndromes shift in response to increased disease prevalence in this plant-pathogen system. In doing so, we address a vital gap in our understanding of global patterns of functional trait variation and highlight the need to further explore the potential role of pathogens within established global trait relationships and spectra.
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