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1.
PeerJ ; 12: e17877, 2024.
Article in English | MEDLINE | ID: mdl-39131614

ABSTRACT

Background: Plants allocate resources to growth, defense, and stress resistance, and resource availability can affect the balance between these allocations. Allocation patterns are well-known to differ among species, but what controls possible intra-specific trade-offs and if variation in growth vs. defense potentially evolves in adaptation to resource availability. Methods: We measured growth and defense in a provenance trial of rubber trees (Hevea brasiliensis) with clones originating from the Amazon basin. To test hypotheses on the allocation to growth vs. defense, we relate biomass growth and latex production to wood and leaf traits, to climate and soil variables from the location of origin, and to the genetic relatedness of the Hevea clones. Results: Contrary to expectations, there was no trade-off between growth and defense, but latex yield and biomass growth were positively correlated, and both increased with tree size. The absence of a trade-off may be attributed to the high resource availability in a plantation, allowing trees to allocate resources to both growth and defense. Growth was weakly correlated with leaf traits, such as leaf mass per area, intrinsic water use efficiency, and leaf nitrogen content, but the relative investment in growth vs. defense was not associated with specific traits or environmental variables. Wood and leaf traits showed clinal correlations to the rainfall and soil variables of the places of origin. These traits exhibited strong phylogenetic signals, highlighting the role of genetic factors in trait variation and adaptation. The study provides insights into the interplay between resource allocation, environmental adaptations, and genetic factors in trees. However, the underlying drivers for the high variation of latex production in one of the commercially most important tree species remains unexplained.


Subject(s)
Hevea , Latex , Plant Leaves , Hevea/genetics , Hevea/growth & development , Plant Leaves/genetics , Plant Leaves/growth & development , Plant Leaves/metabolism , Latex/metabolism , Biomass , Wood/genetics , Phylogeny , Species Specificity
2.
Mar Environ Res ; 200: 106670, 2024 Aug 03.
Article in English | MEDLINE | ID: mdl-39121573

ABSTRACT

Sessile marine invertebrates usually follow a distinct pattern of living in dense aggregations or as solitary individuals. However, at least some serpulins, including Spirobranchus cariniferus, seem to be able to settle aggregative or solitary. To understand how living solitary or in aggregation is beneficial, it is essential to understand the advantages and disadvantages of both settlement strategies for sessile invertebrates. Benefits of living in aggregations include securing suitable habitat, improving the probability of survival by mitigating physical stress and increasing reproductive success. However, living in patches also comes with some disadvantages for the individual, such as higher intra- and interspecific competition for food, space and oxygen. Increased physiological stress can lead to increased mortality and decreased reproductive success, whereas solitary individuals could produce more gametes because of a lack of competition for food and space. On the other hand, predators would have easier access to them, and the possibility of fertilisation success may be lower because of a lack of synchronisation and a greater distance between individuals of different sexes. These issues have not been sufficiently addressed, particularly for serpulids. Individuals of the New Zealand endemic polychaete Spirobranchus cariniferus can be found solitary and aggregative in the same habitat. Therefore, this study is the first on serpulids comparing the growth and mortality of individuals living alone or in aggregations. Hence, bi-monthly observation of mortality and growth measurements were conducted on tagged individuals in the field, and weekly observations were conducted in a laboratory-based study on individuals of both settlement configurations. A final comparison of body metrics to tube dimensions was made by removing an individual from their tube. My findings revealed that while solitary and aggregative individuals elongate their tubes at a similar rate, further correlations of the body to tube sizes lead to the conclusion that solitary worms focus more of their energy on tube growth rather than body size increment than aggregative conspecifics. Mortality is highly variable and seems not to differ between both configurations. However, individuals living in a patch can better recover from damage to their tubes. Here presented observations hopefully initiated further studies into the effects of aggregation size and density on individual growth. Results of this and subsequent studies can inform the management efforts for reefs of serpulins, bivalves and other invertebrates.

3.
Angew Chem Int Ed Engl ; : e202410881, 2024 Aug 10.
Article in English | MEDLINE | ID: mdl-39126280

ABSTRACT

Industrial fermentation applications typically require enzymes that exhibit high stability and activity at high temperatures. However, efforts to simultaneously improve these properties are usually limited by a trade-off between stability and activity. This report describes a computational strategy to enhance both activity and thermal stability of the mesophilic organophosphate-degrading enzyme, methyl parathion hydrolase (MPH). To predict hotspot mutation sites, we assembled a library of features associated with the target properties for each residue and then prioritized candidate sites by hierarchical clustering. Subsequent in silico screening with multiple algorithms to simulate selective pressures yielded a subset of 23 candidate mutations. Iterative parallel screening of mutations that improved thermal stability and activity yielded, MPHase-m5b, which exhibited 13.3 °C higher Tm and 4.2 times higher catalytic activity than wild-type (WT) MPH over a wide temperature range. Systematic analysis of crystal structures, molecular dynamics (MD) simulations, and Quantum Mechanics/Molecular Mechanics (QM/MM) calculations revealed a wider entrance to the active site that increased substrate access with an extensive network of interactions outside the active site that reinforced αß/ßα sandwich architecture to improve thermal stability. This study thus provides an advanced, rational design framework to improve efficiency in engineering highly active, thermostable biocatalysts for industrial applications.

4.
Environ Sci Technol ; 2024 Aug 08.
Article in English | MEDLINE | ID: mdl-39115177

ABSTRACT

Breaking the activity-selectivity trade-off has been a long-standing challenge in catalysis. Here, we proposed a nanoheterostructure engineering strategy to overcome the trade-off in metal phosphide catalysts for the oxidative desulfurization (ODS) of fuels. Experimental and theoretical results demonstrated that electron delocalization was the key driver to simultaneously achieve high activity and high selectivity for the molybdenum phosphide (MoP)/tungsten phosphide (WP) nanoheterostructure catalyst. The electron delocalization not only promoted the catalytic pathway transition from predominant radicals to singlet oxygens in H2O2 activation but also simultaneously optimized the adsorption of reactants and intermediates on Mo and W sites. The presence of such dual-enhanced active sites ideally compensated for the loss of activity due to the nonradical catalytic pathway, consequently disentangling the activity-selectivity trade-off. The resulting catalyst (MoWP2/C) unprecedentedly achieved 100% removal of thiophenic compounds from real diesel at an initial concentration of 2676 ppm of sulfur with a high turnover frequency (TOF) of 105.4 h-1 and a minimal O/S ratio of 4. This work provides fundamental insight into the structure-activity-selectivity relationships of heterogeneous catalysts and may inspire the development of high-performance catalysts for ODS and other catalytic fields.

5.
Natl Sci Rev ; 11(9): nwae141, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39144750

ABSTRACT

Neural networks demonstrate vulnerability to small, non-random perturbations, emerging as adversarial attacks. Such attacks, born from the gradient of the loss function relative to the input, are discerned as input conjugates, revealing a systemic fragility within the network structure. Intriguingly, a mathematical congruence manifests between this mechanism and the quantum physics' uncertainty principle, casting light on a hitherto unanticipated interdisciplinarity. This inherent susceptibility within neural network systems is generally intrinsic, highlighting not only the innate vulnerability of these networks, but also suggesting potential advancements in the interdisciplinary area for understanding these black-box networks.

6.
J Anim Sci ; 2024 Aug 12.
Article in English | MEDLINE | ID: mdl-39132682

ABSTRACT

Endemic and epidemic outbreaks of porcine reproductive and respiratory syndrome virus (PRRSV) are causing large economic losses in commercial pig production worldwide. Given the complexity of controlling this disease with vaccines or other biosecurity measures, the selection for pigs with a natural resilience to this infection has been proposed as an alternative approach. In this context, we previously reported a vaccine-based protocol to classify 6-week-old female piglets from one farm into resilient and susceptible phenotypes. Subsequent analysis showed that resilient sows had fewer lost piglets during a PRRSV epidemic. In the present study, we validated the results in four additional farms by showing a robust effect on the percentage of piglets lost (P<0.05). We were able to associate the resilient phenotype with a 2-4% reduction in piglet losses on sow farms in both endemic and endemic/epidemic situations. Also consistent with previous results, susceptible sows delivered on average, almost 0.5 more piglets born per parity (P<0.05). However, we show here that resilient sows have a longer stayability in the farm (+57 d; P<0.05) and +0.3 more successful parities (P<0.05), which balances the total number of piglets born and born alive in the full productive life of the sow between the two groups. Resilient sows thus contribute towards to a more sustainable production system, reducing sow replacement and piglet mortality. The validation of this protocol on four independent production farms paves the way for the study of the genetic variation underlying the resilient/susceptible classification, with a view to incorporating this information into selection programs in the future.

7.
Ann Bot ; 2024 Aug 12.
Article in English | MEDLINE | ID: mdl-39132894

ABSTRACT

BACKGROUND AND AIMS: Epichloë endophytes are vertically transmitted via grass seeds and chemically defend their hosts against herbivory. Endophyte-conferred plant defence via alkaloid biosynthesis may occur independently of costs for host plant growth. However, fitness consequences of endophyte-conferred defence and transgenerational effects on herbivore resistance of progeny plants, are rarely studied. The aim of this study was to test whether severe defoliation in mother plants affects their seed production, seed germination rate, and the endophyte-conferred resistance of progeny plants. METHODS: In a field study, we tested the effects of defoliation and endophyte symbiosis (Epichloë uncinata) on host plant (Festuca pratensis) performance, loline alkaloid concentrations in leaves and seeds, seed biomass and seed germination rates. In a subsequent greenhouse study, we challenged the progeny of the plants from the field study to aphid herbivory and tested whether defoliation of mother plants affects endophyte-conferred resistance against aphids in progeny plants. KEY RESULTS: Defoliation of the mother plants resulted in a reduction of alkaloid concentrations in leaves and elevated the alkaloid concentrations in seeds when compared with non-defoliated endophyte-symbiotic plants. Viability and germination rate of seeds of defoliated endophyte-symbiotic plants were significantly lower compared to those of non-defoliated endophyte-symbiotic plants and endophyte-free (defoliated and non-defoliated) plants. During six weeks growth, seedlings of defoliated endophyte-symbiotic mother plants had elevated alkaloid concentrations, which negatively correlated with aphid performance. CONCLUSIONS: Endophyte-conferred investment in higher alkaloid levels in seeds -elicited by defoliation- provided herbivore protection in progenies during the first weeks of plant establishment. Better protection of seeds via high alkaloid concentrations negatively correlated with seed germination indicating trade-off between protection and viability.

8.
Conserv Physiol ; 12(1): coae045, 2024.
Article in English | MEDLINE | ID: mdl-38974502

ABSTRACT

In the age of global climate change, extreme climatic events are expected to increase in frequency and severity. Animals will be forced to cope with these novel stressors in their environment. Glucocorticoids (i.e. 'stress' hormones) facilitate an animal's ability to cope with their environment. To date, most studies involving glucocorticoids focus on the immediate physiological effects of an environmental stressor on an individual, few studies have investigated the long-term physiological impacts of such stressors. Here, we tested the hypothesis that previous exposure to an environmental stressor will impart lasting consequences to an individual's glucocorticoid levels. In semi-arid environments, variable rainfall drives forage availability for herbivores. Reduced seasonal precipitation can present an extreme environmental stressor potentially imparting long-term impacts on an individual's glucocorticoid levels. We examined the effects of rainfall and environmental characteristics (i.e. soil and vegetation attributes) during fawn-rearing (i.e. summer) on subsequent glucocorticoid levels of female white-tailed deer (Odocoileus virginianus) in autumn. We captured 124 adult (≥2.5-year-old) female deer via aerial net-gunning during autumn of 2015, 2016 and 2021 across four populations spanning a gradient of environmental characteristics and rainfall in the semi-arid environment of South Texas, USA. We found for every 1 cm decrease in summer rainfall, faecal glucocorticoid levels in autumn increased 6.9%, but only in lactating females. Glucocorticoid levels in non-lactating, female deer were relatively insensitive to environmental conditions. Our study demonstrates the long-lasting effects of environmental stressors on an individual's glucocorticoid levels. A better understanding of the long-term effects stressors impart on an individual's glucocorticoid levels will help to evaluate the totality of the cost of a stressor to an individual's welfare and predict the consequences of future climate scenarios.

9.
Eur J Health Econ ; 2024 Jul 09.
Article in English | MEDLINE | ID: mdl-38982011

ABSTRACT

BACKGROUND: In many countries, methods of economic evaluation and Health Technology Assessment are used to inform healthcare resource allocation decisions. These approaches often require EQ-5D health outcomes measures. This study aimed to create an EQ-5D-3L value set for Bermuda from which EQ-5D-5L Crosswalk values could be obtained. METHODS: Respondents in Bermuda were recruited locally. A team of Trinidad-based interviewers with prior EQ-5D-3L valuation experience conducted valuation interviews on-line using the EQ-VT protocol. Respondents completed composite time-trade off (cTTO) and discrete choice experiment (DCE) tasks. A hybrid model that included both the cTTO and DCE data was estimated. An EQ-5D-5L crosswalk value set was then created from the EQ-5D-3L index values. Coefficients in the resulting crosswalk model were compared with those of crosswalk and valuation studies from other countries. RESULTS: The valuation tasks were completed by a near-representative sample of 366 adult Bermuda citizens. Half of the respondents reported being in state 11111. The lowest EQ VAS and EQ-5D-3L index values were 20 and - 0.120 respectively. The hybrid model produced all logically consistent and statistically significant coefficients that in turn produced index values that were very similar to those obtained in a preliminary model (MAD of 0.027). DISCUSSION: The on-line EQ-VT valuation study was successfully conducted in Bermuda and the values therein can now be used for economic analysis in Bermuda. The Bermuda values differed considerably from those of the other countries against which they were compared. Challenges were encountered with recruitment for an on-line survey in a small population.

10.
J Am Stat Assoc ; 119(546): 1297-1308, 2024.
Article in English | MEDLINE | ID: mdl-38984070

ABSTRACT

Extreme environmental events frequently exhibit spatial and temporal dependence. These data are often modeled using max stable processes (MSPs) that are computationally prohibitive to fit for as few as a dozen observations. Supposed computationally-efficient approaches like the composite likelihood remain computationally burdensome with a few hundred observations. In this paper, we propose a spatial partitioning approach based on local modeling of subsets of the spatial domain that delivers computationally and statistically efficient inference. Marginal and dependence parameters of the MSP are estimated locally on subsets of observations using censored pairwise composite likelihood, and combined using a modified generalized method of moments procedure. The proposed distributed approach is extended to estimate inverted MSP models, and to estimate spatially varying coefficient models to deliver computationally efficient modeling of spatial variation in marginal parameters. We demonstrate consistency and asymptotic normality of estimators, and show empirically that our approach leads to statistically efficient estimation of model parameters. We illustrate the flexibility and practicability of our approach through simulations and the analysis of streamflow data from the U.S. Geological Survey.

11.
Animals (Basel) ; 14(13)2024 Jun 25.
Article in English | MEDLINE | ID: mdl-38997988

ABSTRACT

Behaviour is often the fundamental driver of disease transmission, where behaviours of individuals can be seen to scale up to epidemiological patterns seen at the population level. Here we focus on animal behaviour, and its role in parasite transmission to track its knock-on consequences for parasitism, production and pollution. Livestock face a nutrition versus parasitism trade-off in grazing environments where faeces creates both a nutritional benefit, fertilizing the surrounding sward, but also a parasite risk from infective nematode larvae contaminating the sward. The grazing decisions of ruminants depend on the perceived costs and benefits of the trade-off, which depend on the variations in both environmental (e.g., amounts of faeces) and animal factors (e.g., physiological state). Such grazing decisions determine the intake of both nutrients and parasites, affecting livestock growth rates and production efficiency. This impacts on the greenhouse gas costs of ruminant livestock production via two main mechanisms: (1) slower growth results in longer durations on-farm and (2) parasitised animals produce more methane per unit food intake. However, the sensitivity of behaviour to host parasite state offers opportunities for early detection of parasitism and control. Remote monitoring technology such as accelerometers can detect parasite-induced sickness behaviours soon after exposure, before impacts on growth, and thus may be used for targeting individuals for early treatment. We conclude that livestock host x parasite interactions are at the centre of the global challenges of food security and climate change, and that understanding livestock behaviour can contribute to solving both.

12.
Int J Plant Sci ; 185(3): 218-227, 2024 May.
Article in English | MEDLINE | ID: mdl-39035046

ABSTRACT

An understanding of biological fitness is central to theory and practice in ecology and evolution, yet fitness remains an elusive concept to define and challenging to measure accurately. Fitness reflects an individual's ability to pass its alleles on to subsequent generations. Researchers often quantify proxies for fitness, such as survival, growth or reproductive success. However, it can be difficult to determine lifetime fitness, especially for species with long lifespans. The abiotic and biotic environment strongly affects the expression of fitness, which means that fitness components can vary through both space and time. This spatial and temporal heterogeneity results in the impressive range of adaptations that we see in nature. Here, we review definitions of fitness and approaches to measuring fitness at the level of genes, individuals, genotypes, and populations and highlight that fitness is a key concept linking ecological and evolutionary thought.

13.
J Therm Biol ; 123: 103912, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-39024848

ABSTRACT

The intensity and duration of heat waves, as well as average global temperatures, are expected to increase due to climate change. Heat waves can cause physiological stress and reduce fitness in animals. Species can reduce overheating risk through phenotypic plasticity, which allows them to raise their thermal tolerance limits over time. This mechanism could be important for ectotherms whose body temperatures are directly influenced by available environmental temperatures. Geckos are a large, diverse group of ectotherms that vary in their thermal habitats and times of daily activity, which could affect how they physiologically adjust to heat waves. Data on thermal physiology are scarce for reptiles, with only one study in geckos. Understanding thermal tolerance and plasticity, and their relationship, is essential for understanding how some species are able to adjust or adapt to changing temperatures. In this study, we estimated thermal tolerance and plasticity, and their interaction, in the crepuscular gecko, Eublepharis macularius, a species that is emerging as a model for reptile biology. After estimating basal thermal tolerance for 28 geckos, thermal tolerance was measured for each individual a second time at several timepoints (3, 6, or 24 h) to determine thermal tolerance plasticity. We found that thermal tolerance plasticity (1) does not depend on the basal thermal tolerance of the organism, (2) was highest after 6 h from initial heat shock, and (3) was negatively influenced by individual body mass. Our findings contribute to the increasing body of work focused on understanding the influence of biological and environmental factors on thermal tolerance plasticity in organisms and provide phenotypic data to further investigate the molecular basis of thermal tolerance plasticity in organisms.

14.
R Soc Open Sci ; 11(5): 231301, 2024 May.
Article in English | MEDLINE | ID: mdl-39076806

ABSTRACT

Airborne dispersal of microorganisms is a ubiquitous migration mechanism, allowing otherwise independent microbial habitats to interact via biomass exchange. Here, we study the ecological implications of such advective transport using a simple spatial model for bacteria-phage interactions: the population dynamics at each habitat are described by classical Lotka-Volterra equations; however, species populations are taken as integer, that is, a discrete, positive extinction threshold exists. Spatially, species can spread from habitat to habitat by stochastic airborne dispersal. In any given habitat, the spatial biomass exchange causes incessant population density oscillations, which, as a consequence, occasionally drive species to extinction. The balance between local extinction events and dispersal-induced migration allows species to persist globally, even though diversity would be depleted by competitive exclusion, locally. The disruptive effect of biomass dispersal thus acts to increase microbial diversity, allowing system-scale coexistence of multiple species that would not coexist locally.

15.
BMC Biol ; 22(1): 163, 2024 Jul 29.
Article in English | MEDLINE | ID: mdl-39075492

ABSTRACT

BACKGROUND: Energy allocation between growth and reproduction determines puberty onset and fertility. In mammals, peripheral hormones such as leptin, insulin and ghrelin signal metabolic information to the higher centres controlling gonadotrophin-releasing hormone neurone activity. However, these observations could not be confirmed in lower vertebrates, suggesting that other factors may mediate the energetic trade-off between growth and reproduction. A bioinformatic and experimental study suggested co-regulation of the circadian clock, reproductive axis and growth-regulating genes in zebrafish. While loss-of-function of most of the identified co-regulated genes had no effect or only had mild effects on reproduction, no such information existed about the co-regulated somatostatin, well-known for its actions on growth and metabolism. RESULTS: We show that somatostatin signalling is pivotal in regulating fecundity and metabolism. Knock-out of zebrafish somatostatin 1.1 (sst1.1) and somatostatin 1.2 (sst1.2) caused a 20-30% increase in embryonic primordial germ cells, and sst1.2-/- adults laid 40% more eggs than their wild-type siblings. The sst1.1-/- and sst1.2-/- mutants had divergent metabolic phenotypes: the former had 25% more pancreatic α-cells, were hyperglycaemic and glucose intolerant, and had increased adipocyte mass; the latter had 25% more pancreatic ß-cells, improved glucose clearance and reduced adipocyte mass. CONCLUSIONS: We conclude that somatostatin signalling regulates energy metabolism and fecundity through anti-proliferative and modulatory actions on primordial germ cells, pancreatic insulin and glucagon cells and the hypothalamus. The ancient origin of the somatostatin system suggests it could act as a switch linking metabolism and reproduction across vertebrates. The results raise the possibility of applications in human and animal fertility.


Subject(s)
Energy Metabolism , Reproduction , Signal Transduction , Somatostatin , Zebrafish , Animals , Zebrafish/genetics , Zebrafish/metabolism , Reproduction/physiology , Somatostatin/metabolism , Somatostatin/genetics , Zebrafish Proteins/metabolism , Zebrafish Proteins/genetics , Fertility , Female
16.
Plant Cell ; 2024 Jul 26.
Article in English | MEDLINE | ID: mdl-39056470

ABSTRACT

In Arabidopsis (Arabidopsis thaliana), overproduction of salicylic acid (SA) increases disease resistance and abiotic stress tolerance but penalizes growth. This growth-defense trade-off has hindered the adoption of SA-based disease management strategies in agriculture. However, investigation of how SA inhibits plant growth has been challenging because many SA-hyperaccumulating Arabidopsis mutants have developmental defects due to the pleiotropic effects of the underlying genes. Here, we heterologously expressed a bacterial SA synthase gene in Arabidopsis and observed that elevated SA levels decreased plant growth and reduced the expression of cold-regulated (COR) genes in a dose-dependent manner. Growth suppression was exacerbated at below-ambient temperatures. Severing the SA-responsiveness of individual COR genes was sufficient to overcome the growth inhibition caused by elevated SA at ambient and below-ambient temperatures while preserving disease- and abiotic-stress-related benefits. Our results show the potential of decoupling SA-mediated growth and defense trade-offs for improving crop productivity.

17.
Value Health Reg Issues ; 44: 101026, 2024 Jul 25.
Article in English | MEDLINE | ID: mdl-39059264

ABSTRACT

OBJECTIVES: This systematic literature review aimed to explore experiences worldwide of societal preferences integration into health technology assessments (HTAs) for rare diseases (RDs) and orphan drugs (ODs) through the implementation of multicriteria decision analysis (MCDA), discrete choice experiments (DCEs), and person trade-off (PTO) methods, among others. METHODS: A systematic search of the literature was conducted in April 2021 using PubMed, Cochrane, Embase, and Scopus databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses approach was used for the review phases. Finally, the Promoting Action on Research Implementation in Health Services framework was used to discuss the implementation of these instruments in the RD context. RESULTS: A total of 33 articles met the inclusion criteria. The studies measured societal preferences for RD and OD as part of HTA using MCDA (n = 17), DCE (n = 8), and PTO (n = 4), among other methods (n = 4). These found that patients and clinicians do not prioritize funding based on rarity. The public is willing to allocate funds only if the OD demonstrates effectiveness and improves the quality of life, considering as relevant factors disease severity, unmet health needs, and quality of life. Conversely, HTA agency experts preferred their current approach, placing more weight on cost-effectiveness and evidence quality, even though they expressed concern about the fairness of the drug review process. CONCLUSIONS: MCDA, PTO, and DCE are helpful and transparent methods for assessing societal preferences in HTA for RD and OD. However, their methodological limitations, such as arbitrary criteria selection, subjective scoring methods, framing effects, weighting adaptation, and value measurement models, could make implementation challenging.

18.
Ecol Evol ; 14(7): e11414, 2024 Jul.
Article in English | MEDLINE | ID: mdl-39045503

ABSTRACT

Life-history theory predicts that investment in reproduction should decrease survival (the 'cost of reproduction'). It is often assumed that energy allocation drives such trade-offs, with limited energy available for both reproduction and survival. However, the underlying mechanisms remain poorly understood, maybe because survival costs of reproduction are only apparent when resources are limited. Here, we took advantage of a natural experiment created by fluctuating environmental conditions to compare energy expenditure of a seabird, the pelagic cormorant (Phalacrocorax pelagicus), between contrasting population-scale scenarios of survival costs of reproduction. We used multi-state capture-recapture modelling across 16 years to identify which breeding seasons induced high survival costs (survival ratebreeders < survival ratenon/failed breeders) and we concomitantly estimated energy expenditure of chick-rearing males using time-energy budget models across 4 years. Daily energy expenditure (DEE) of chick-rearing pelagic cormorants varied significantly among years. However, survival costs of reproduction were observed in only 1 year, and contrary to our expectations, variation in DEE was not associated with population-level survival costs. Similarly, at the individual level, DEE in 1 year did not predict the probability of being observed again at the colony in following years (apparent survival). Finally, DEE was independent of brood size and brood age, but older individuals tended to expend less energy than younger ones. Given the lack of an apparent energetic 'cost of reproduction', lower DEE in older birds could be due to improved efficiency rather than avoidance of costs in old birds. Although future studies should account for potential sex-specific energetic constraints by including data on female energy expenditure, we conclude that a direct link between the rate of energy expenditure during breeding and subsequent survival is unlikely in this system.

19.
J Environ Manage ; 366: 121745, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38991355

ABSTRACT

Identifying the response characteristics of ecosystem service value (ESV) to changes in spatial scales, known as spatial scale effects, is crucial in guiding the development of corresponding management strategies. This paper examines ESV in China's terrestrial area during the year 2020, revealing the spatial aggregation characteristics of ESV and the trade-off and synergistic relationships of ecosystem services at different spatial scales, ranging from 1 km × 1 km-10 km × 10 km, with a gradient of 1 km. The results indicate: 1) The distribution pattern of ESV in China's terrestrial area is "high in the southeast and low in the northwest." 2) The spatial characteristics of ESV in China's terrestrial area undergo a distinct transition at the 3 km × 3 km scale. In detail, the spatial clustering features show a trend of first rising and then falling with the increase in spatial scale, while the synergistic relationships between different ecosystem services strengthen and the trade-off relationships weaken with the increase of the spatial scale. These findings can inform the formulation of differentiated ecological protection compensation policies and enable cross-area trading of ecological values in China.


Subject(s)
Conservation of Natural Resources , Ecosystem , China
20.
Cell Rep ; 43(7): 114515, 2024 Jul 23.
Article in English | MEDLINE | ID: mdl-39003743

ABSTRACT

Wounding is a general stress in plants that results from various pest and pathogenic infections in addition to environment-induced mechanical damages. Plants have sophisticated molecular mechanisms to recognize and respond to wounding, with those of monocots being distinct from dicots. Here, we show the involvement of two distinct categories of temporally separated, endogenously derived peptides, namely, plant elicitor peptides (PEPs) and phytosulfokine (PSK), mediating wound responses in rice. These peptides trigger a dynamic signal relay in which a receptor kinase involved in PSK perception named OsPSKR plays a major role. Perturbation of OsPSKR expression in rice leads to compromised development and constitutive autoimmune phenotypes. OsPSKR regulates the transitioning of defense to growth signals upon wounding. OsPSKR displays mutual antagonism with the OsPEPR1 receptor involved in PEP perception. Collectively, our work indicates the presence of a stepwise peptide-mediated signal relay that regulates the transition from defense to growth upon wounding in monocots.


Subject(s)
Oryza , Plant Proteins , Signal Transduction , Oryza/metabolism , Oryza/genetics , Plant Proteins/metabolism , Plant Proteins/genetics , Gene Expression Regulation, Plant , Peptides/metabolism , Plant Diseases/immunology
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