unpredictable environments
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2022 ◽  
Author(s):  
Hanna ten Brink ◽  
Thomas Ray Haaland ◽  
Oystein Hjorthol Opedal

The common occurrence of within-population variation in germination behavior and associated traits such as seed size has long fascinated evolutionary ecologists. In annuals, unpredictable environments are known to select for bet-hedging strategies causing variation in dormancy duration and germination strategies. Variation in germination timing and associated traits is also commonly observed in perennials, and often tracks gradients of environmental predictability. Although bet-hedging is thought to occur less frequently in long-lived organisms, these observations suggest a role of bet-hedging strategies in perennials occupying unpredictable environments. We use complementary numerical and evolutionary simulation models of within- and among-individual variation in germination behavior in seasonal environments to show how bet-hedging interacts with density dependence, life-history traits, and priority effects due to competitive differences among germination strategies. We reveal substantial scope for bet-hedging to produce variation in germination behavior in long-lived plants, when "false starts" to the growing season results in either competitive advantages or increased mortality risk for alternative germination strategies. Additionally, we find that two distinct germination strategies can evolve and coexist through negative frequency-dependent selection. These models extend insights from bet-hedging theory to perennials and explore how competitive communities may be affected by ongoing changes in climate and seasonality patterns.


2021 ◽  
pp. 1-10
Author(s):  
Phoebe H. Lam ◽  
Gregory E. Miller ◽  
Lauren Hoffer ◽  
Rebekah Siliezar ◽  
Johanna Dezil ◽  
...  

Abstract The environment has pervasive impacts on human development, and two key environmental conditions – harshness and unpredictability – are proposed to be instrumental in tuning development. This study examined (1) how harsh and unpredictable environments related to immune and clinical outcomes in the context of childhood asthma, and (2) whether there were independent associations of harshness and unpredictability with these outcomes. Participants were 290 youth physician-diagnosed with asthma. Harshness was assessed with youth-reported exposure to violence and neighborhood-level murder rate. Unpredictability was assessed with parent reports of family structural changes. Youth also completed measures of asthma control as well as asthma quality of life and provided blood samples to assess immune profiles, including in vitro cytokine responses to challenge and sensitivity to inhibitory signals from glucocorticoids. Results indicated that harshness was associated with more pronounced pro-inflammatory cytokine production following challenge and less sensitivity to the inhibitory properties of glucocorticoids. Furthermore, youth exposed to harsher environments reported less asthma control and poorer quality of life. All associations with harshness persisted when controlling for unpredictability. No associations between unpredictability and outcomes were found. These findings suggest that relative to unpredictability, harshness may be a more consistent correlate of asthma-relevant immune and clinical outcomes.


Author(s):  
F. Muñoz-Salinas ◽  
E.G. Tovar-Pérez ◽  
R.G. Guevara-González ◽  
G.F. Loarca-Piña ◽  
Irineo Torres-Pacheco

Background: Hydrogen peroxide is reactive oxygen species that plays role in plant response to biotic and abiotic stress. The pretreatment with hydrogen peroxide can confer an adaptive capacity for the plants in unpredictable environments. The alfalfa (Medicago sativa L.) is the legume more utilized in animal feeding in the world. Moreover, the alfalfa sprouts are known for the phytochemicals that promote health with antioxidant properties. Methods: This work aimed to determine the effect of hydrogen peroxide in the pretreatment process of alfalfa seeds on variables as total germination, speed of germination, activity and antioxidant enzymes. The alfalfa seeds were soaked for 12 h in the next treatments 0, 98, 294, 490, 784, 980 mM of hydrogen peroxide. Result: The results showed that total germination was higher with the hydrogen peroxide than with water except 980 mM. The results of the present research indicated that hydrogen peroxide had physiological and biochemical effects on the germination processes of alfalfa.


Author(s):  
Pedro Fernandes Anunciação ◽  
Nuno Santos Geada

Organizations function in complex, dynamic and unpredictable environments. Implementing changes must therefore be well planned, managed, and evaluated as such ongoing efforts link organizational performance to peer competitiveness and sustainability. In an era challenged with technological innovations, it is crucial to understand how new changes can leverage traditional methodologies and services supported by information and technology systems. As information-intensive organizations such as hospitals are highly dependent on changing information and technological systems, this understanding is key to evolve next generation hospitals. Specifically, this study analyzes how hospital managers in Portugal relate change to information systems’ management based on Information Technology Infrastructure Library methodology. The relationship between change and information technologies services is not sufficiently clarified and constitutes an excellent opportunity to increase knowledge in the field of information systems.


2021 ◽  
Vol 17 (7) ◽  
pp. 20210286
Author(s):  
Barbara Class ◽  
Giulia Masoero ◽  
Julien Terraube ◽  
Erkki Korpimäki

Food-hoarding behaviour is widespread in the animal kingdom and enables predictable access to food resources in unpredictable environments. Within species, consistent variation among individuals in food-hoarding behaviours may indicate the existence of individual strategies, as it likely captures intrinsic differences in how individuals cope with risks (e.g. starvation, pilferage). Using 17 years of data, we estimated the long-term repeatability of 10 food-hoarding behaviours in a population of Eurasian pygmy owls ( Glaucidium passerinum ), a small avian predator subject to high temporal fluctuations in its main prey abundance. We found low repeatability in the proportion of shrews and the average prey mass stored for both sexes, while females were moderately repeatable in the mass and the number of prey items stored. These two pairs of behaviours were tightly correlated among individuals and might represent two different sets of individual strategies to buffer against starvation risks.


Author(s):  
G. Jayanth Kumar

The small autonomous vehicles of the future will have to navigate close to obstacles in highly unpredictable environments. Risky tasks of this kind may require novel sensors and control methods that differ from conventional approaches. Recent ethological findings have shown that complex navigation tasks such as obstacle avoidance and speed control are performed by flying insects on the basis of optic flow (OF) cues, although insects' compound eyes have a very poor spatial resolution. The implementation of an optic flow-based autopilot on a fully autonomous hovercraft. Tests were performed on this small (878-gram) innovative robotic platform in straight and tapered corridors lined with natural panoramas. A bilateral OF regulator controls the robot's forward speed (up to 0.8m/s), while a unilateral OF regulator controls the robot's clearance from the two walls. A micro-gyrometer and a tiny magnetic compass ensure that the hovercraft travels forward in the corridor without yawing. The lateral OFs are measured by two minimalist eyes mounted sideways opposite to each other. For the first time, the hovercraft was found to be capable of adjusting both its forward speed and its clearance from the walls, in both straight and tapered corridors, without requiring any distance or speed measurements, that is, without any need for on-board rangefinders or tachometers.


Crop Science ◽  
2021 ◽  
Author(s):  
Rachel Lynn Veenstra ◽  
Carlos Messina ◽  
Dan Berning ◽  
Lucas A. Haag ◽  
Paul Carter ◽  
...  

Author(s):  
Mohammad Fakhar Manesh ◽  
Giulia Flamini ◽  
Damiano Petrolo ◽  
Rocco Palumbo

AbstractThe dance metaphor allows us to figuratively depict entrepreneurial decision making processes. Being conventionally conceived of as a sequence of purposeful behaviors rooted in a rational cognition process, entrepreneurial decision making can be featured as a ‘ballet’. This interpretation puts in the background the improvisational nature of decision making, which revokes ‘lindy hop’ as a dance style. The article intends to illuminate the role of intuition, highlighting its overlap with rationality in the entrepreneurial decision making dance. For this purpose, a bibliometric analysis followed by an interpretive literature review advances a comprehensive report of 66 peer-reviewed journal articles published from 1995 to 2019, constructing evidence on the nature of entrepreneurial decision making and on the interplay between intuition and rationality. Literature is categorized in five clusters, which are reciprocally intertwined. Firstly, intuition is unconsciously used as a strategy to deal with the uncertainty that inherently affects entrepreneurial ventures. Secondly, intuition is rooted in the entrepreneurs’ impulsivity, that echoes the role of emotions in decision making. Thirdly, the merge of rationality and intuition improves the entrepreneurs’ ability to keep up with the erratic rhythm of the decision making dance. Fourthly, the mix of intuition and rationality serves as a catalyst of entrepreneurs’ ability to thrive in complex and unpredictable environments. Fifthly, intuition generates drawbacks on entrepreneurs’ meta-cognitive knowledge, which should be carefully recognized. Embracing the dance metaphor, intuition turns out to be crucial to make entrepreneurs able to fill in the gap between rationality and uncertainty.


2021 ◽  
pp. 002188632110093
Author(s):  
António C. M. Abrantes ◽  
Ana Margarida Passos ◽  
Miguel Pina e Cunha ◽  
Catarina Marques Santos

Organizational teams operate in increasingly volatile environments in which the speed and degree of change accelerates, demanding rapid adaptation processes namely of the improvisational type. It is therefore essential to understand how to prepare teams to operate in such contexts. This work investigates the effects of team mental model similarity, in-action reflexivity, and transitional reflexivity on team-improvised adaptation performance and on team-improvised adaptation learning. Two experiments were conducted with a total of 121 teams. We manipulated the independent variables and used an overtime design to measure team-improvised adaptation learning. Our findings suggest that teams operating in unpredictable environments that require rapid adaptation should be able to reflect collectively, both while acting and between tasks. These teams should also develop a common understanding of the main elements of the context and the task, so that they are effective in the face of unpredictability and rapid change.


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