Response of plant functional traits at species and community levels to grazing exclusion on Inner Mongolian steppe, China

2018 ◽  
Vol 40 (2) ◽  
pp. 179 ◽  
Author(s):  
Jinghui Zhang ◽  
Yongmei Huang ◽  
Huiying Chen ◽  
Jirui Gong ◽  
Yu Qi ◽  
...  
Keyword(s):  
Growth Rate ◽  
Functional Traits ◽  
Ecosystem Function ◽  
High Capacity ◽  
Plant Functional Traits ◽  
Grazing Management ◽  
Short Term ◽  
Grazing Exclusion ◽  
Typical Steppe

Variations in ecosystem function in response to land-use changes may be expected to reflect differences in the functional traits of plants. In this study, we sought to reveal the relationship between trait variability and grazing management on typical steppe in Inner Mongolia, and explore the implications of this relationship for ecosystem functioning. We measured aboveground biomass and 18 functional traits of the most abundant plant species in a grassland subject to three grazing-management regimes: long-term grazing, short-term grazing exclusion (since 2008) and long-term grazing exclusion (since 1956). Principal component analysis of the variation in species-level traits revealed trade-offs between the traits that enabled rapid acquisition of resources by fast-growing annual species and those that promoted conservation of resources by perennial grasses, especially Stipa grandis. However, there was no systematic pattern of intra-specific variation in trait values recorded among sites. Aggregation of plant functional traits to the community level revealed a gradient of responses of typical steppe to grazing exclusion. Long-term grazing favoured species whose traits indicate low forage quality and relatively low growth rate. Exclusion of grazing for several years favoured species whose traits indicate relatively high growth rate and high capacity to acquire resources. Exclusion of grazing for several decades favoured species whose morphological and physiological traits indicated low growth rates and high capacity for resource conservation. These community-level traits imply that ecosystem carbon and nutrient stores will change in response to the grazing regime. Long-term grazing will result in decreased plant carbon and nitrogen content, and will lead to carbon and nutrient loss, whereas short-term and long-term grazing exclusion are beneficial to the recovery of carbon and nutrient storage. The findings support the value of community aggregated traits as indicators of environmental or management change and for explaining changes in ecosystem function.

ON THE CONSUMPTION/DISTRIBUTION THEOREM UNDER THE LONG-RUN GROWTH CRITERION SUBJECT TO A DRAWDOWN CONSTRAINT

2010 ◽  
Vol 13 (06) ◽  
pp. 931-957 ◽  
Author(s):  
MICHAEL J. KLASS ◽  
KRZYSZTOF NOWICKI
Keyword(s):  
Growth Rate ◽  
Short Term ◽  
Long Run ◽  
Time Period ◽  
Total Capital ◽  
Growth Criterion ◽  
Drawdown Constraint ◽  
Riskless Asset ◽  
Distribution Theorem

Consider any discrete time sequence of investment fortunes Fn which has a finite long-run growth rate [Formula: see text] when subject to the present value capital drawdown constraint Fne-rn ≥ λ* max 0≤k≤nFke-rk, where 0 ≤ λ* < 1, in the presence of a riskless asset affording a return of er dollars per time period per dollar invested. We show that money can be withdrawn for consumption from the invested capital without either reducing the long-run growth rate of such capital or violating the drawdown constraint for our capital sequence, while simultaneously increasing the amount of capital withdrawn for consumption at the identical long-term rate of V(r, λ*). We extend this result to an exponentially increasing number of consumption categories and discuss how additional yearly contributions can temporarily augment the total capital under management. In addition, we assess the short-term practicality of creating such an endowment/consumption/distribution program.

scholarly journals Prospects for Vietnam’s Economy in 2013

2013 ◽  
Vol 215 ◽  
pp. 02-11
Author(s):  
NGÂN TRẦN HOÀNG
Keyword(s):  
Economic Growth ◽  
Growth Rate ◽  
World Economy ◽  
Inflation Rate ◽  
Economic Restructuring ◽  
Short Term ◽  
Economic Growth Model ◽  
The World ◽  
Global Growth

In 2012, Vietnam?s economy faced great challenges. The world economy experienced more difficulties and complicated upheavals. International trade fell drastically while global growth rate was lower than predicted target, which affected badly the Vietnamese economy because of its full integration into the world economy and large openness. In this context, principal targets set for 2013 are macroeconomic stability, lower inflation rate, higher growth rate, three strategic breakthroughs associated with restructuring of the economy, and a new economic growth model. This paper analyzes obstacles to Vietnam?s economic growth, and offers short-term solutions to bottlenecks and long-term ones to the economic restructuring.

scholarly journals Preventing co-infection: a viral strategy with short-term benefits and long-term drawbacks

2021 ◽  
Author(s):  
Michael Hunter ◽  
Diana Fusco
Keyword(s):  
Growth Rate ◽  
Life History ◽  
Negative Impact ◽  
Viral Evolution ◽  
Viral Fitness ◽  
Viral Population ◽  
Short Term ◽  
Life History Parameters ◽  
Wide Range

ABSTRACTViral co-infection occurs when multiple distinct viral particles infect the same host. This can impact viral evolution through intracellular interactions, complementation, reassortment and recombination. In nature many viral species are found to have a wide range of mechanisms to prevent co-infection, which raises the question of how viral evolution is impacted by this strategic choice. Here, we address this question in a model viral system, the ubiquitous bacteriophage and its host bacteria. Using a stochastic model of phage-host interactions in agent-based simulations, we first characterise the behaviour of neutral mutants and find that co-infection decreases the strength of genetic drift. We then quantify how variations in the phage life history parameters affect viral fitness. Importantly, we find that the growth rate (dis)advantage associated with variations in life history parameters can be dramatically different from the competitive (dis)advantage measured in direct-competition simulations. Additionally, we find that co-infection facilitates the fixation of beneficial mutations and the removal of deleterious ones, suggesting that selection is more efficient in co-infecting populations. We also observe, however, that in populations which allow co-infection, a mutant that prevents it displays a substantial competitive advantage over the rest of the population, and will eventually fix even if it displays a much lower growth rate in isolation. Our findings suggest that while preventing co-infection can have a negative impact on the long-term evolution of a viral population, in the short-term it is ultimately a winning strategy, possibly explaining the prevalence of phage capable of preventing co-infection in nature.

scholarly journals Comparative Analysis of Executive Compensation in the Republic of Serbia and EU Countries

2019 ◽  
Vol 57 (2) ◽  
pp. 181-200
Author(s):  
Ivana Marinović Matović
Keyword(s):  
Comparative Analysis ◽  
Executive Compensation ◽  
High Capacity ◽  
Business Organization ◽  
Business Organizations ◽  
Short Term ◽  
Eu Countries ◽  
Strong Motivation ◽  
The Republic

AbstractExecutive compensations have a strong motivation role in contemporary business organizations. Adequate models of compensation enable attracting and retaining the high-capacity managers. This way, business organization conquers and maintains the competitive position in the context of globalization. It is necessary to align the executive compensation with the business organization’s strategy, which requires careful process of planning, done by the highest levels of management and ownership. The main objective of the paper is to explore and compare the structure and the level of executive compensation in the Republic of Serbia and EU countries. The paper focuses on executive compensation components, primarily long-term and short-term incentives, as well as sallary and benefits. A comparative analysis of executive compensation models was performed to explain the differences in the observed countries.The study found large and disproportionate differences in the executive compensation levels, conditioned mostly by the economic development of the observed economies.

scholarly journals Trade-off Strategy of Three Dominant Species in Grazing Exclusion of Desert Steppe,china

2021 ◽  
Author(s):  
jingli ma ◽  
Hongbin Ma ◽  
Yao Zhou ◽  
Qi Lu ◽  
Yan Shen
Keyword(s):  
Leaf Area ◽  
Functional Traits ◽  
Root Length ◽  
Dominant Species ◽  
Specific Root Length ◽  
Desert Steppe ◽  
Short Term ◽  
Trade Off ◽  
Grazing Exclusion ◽  
Root Functional Traits

Abstract Background and AimsGrazing exclusion is a powerful measure to restore the ecological environment in desert steppe. Studying the changing trend of functional traits and trade-off strategy about dominant species what is of great significance to understand the effect of grazing exclusion on species succession. Methods We studied that the change of leaf and root functional traits of three dominant species (Lespedeza potaninii, Agropyron mongolicum and Stipa breviflora) under different term of grazing exclusion. ResultsWe found that the leaf area and leaf nitrogen content, leaf dry matter content, total root length, specific root length and specific root surface of Lespedeza potaninii in grazing were higher than grazing exclusion. The highest specific leaf area, specific root length of Agropyron mongolicum and Stipa breviflora were observed in short-term grazing exclusion. Leaf tissue density and root tissue density significantly decreased in short-term grazing exclusion. Economic spectrum exist, Lespedeza potaninii have more conservation strategy in short-term grazing exclusion compared with grazing. Agropyron mongolicum and Stipa breviflora have more acquisition strategy in grazing exclusion. Average diameters have great effected on above-ground biomass.ConclusionThe result showed that grazing exclusion change leaf and root functional traits of three dominant species, different species have different trade-off strategy.

The Effects of Consumer Engagement Behavior on the Growth of Social Media Brand Community

2017 ◽  
Vol 13 (1) ◽  
pp. 25-43 ◽  
Author(s):  
Xiaoyun He ◽  
Arash Negahban
Keyword(s):  
Social Media ◽  
Growth Rate ◽  
Brand Community ◽  
Consumer Engagement ◽  
Short Term ◽  
Brand Communities ◽  
Engagement Behavior ◽  
Dynamic Relationships ◽  
Predictive Relationship

In recent years, there has been increasing attention to how consumers' roles and behaviors can shape and affect social media based brand communities. In this study the authors examine the dynamic relationships between specific consumer engagement behaviors and the growth rate of social media brand community over time. The results of their study suggest that the overall consumer engagement behavior has a significant predictive relationship with the growth rate of brand community in both short term and long term. While each type of positive consumer engagement behavior alone is not a significant indicator of the growth rate of brand community, a combination of them, as a whole, has a positive predictive relationship with the growth rate of brand community. When the effect of promotional posts is taken into consideration, consumer sharing is found to have relatively stronger and faster predictive relationship with the growth rate of brand community, followed by commenting and liking, than other consumer engaging activities. Negative consumer engagement behaviors in general do not play a significant role in predicting the growth rate of brand community in long term, but it does lead to adverse effect in the short term. This study sheds insights on the dynamic effects of consumer engagement behavior in building and growing social media based brand communities.

The Effects of Consumer Engagement Behavior on the Growth of Social Media Brand Community

2017 ◽  
pp. 1283-1304
Author(s):  
Xiaoyun He ◽  
Arash Negahban
Keyword(s):  
Social Media ◽  
Growth Rate ◽  
Brand Community ◽  
Consumer Engagement ◽  
Short Term ◽  
Brand Communities ◽  
Engagement Behavior ◽  
Dynamic Relationships ◽  
Predictive Relationship

In recent years, there has been increasing attention to how consumers' roles and behaviors can shape and affect social media based brand communities. In this study the authors examine the dynamic relationships between specific consumer engagement behaviors and the growth rate of social media brand community over time. The results of their study suggest that the overall consumer engagement behavior has a significant predictive relationship with the growth rate of brand community in both short term and long term. While each type of positive consumer engagement behavior alone is not a significant indicator of the growth rate of brand community, a combination of them, as a whole, has a positive predictive relationship with the growth rate of brand community. When the effect of promotional posts is taken into consideration, consumer sharing is found to have relatively stronger and faster predictive relationship with the growth rate of brand community, followed by commenting and liking, than other consumer engaging activities. Negative consumer engagement behaviors in general do not play a significant role in predicting the growth rate of brand community in long term, but it does lead to adverse effect in the short term. This study sheds insights on the dynamic effects of consumer engagement behavior in building and growing social media based brand communities.

Global changes explain the long-term demographic trend of the Eurasian common lizard (Squamata: Lacertidae)

2021 ◽  
Author(s):  
Jose L Horreo ◽  
Patrick S Fitze
Keyword(s):  
Growth Rate ◽  
Population Size ◽  
Effective Population Size ◽  
Climatic Changes ◽  
Vegetation Changes ◽  
Effective Population ◽  
Short Term ◽  
Demographic Trend ◽  
Common Lizard

Abstract The demographic trend of a species depends on the dynamics of its local populations, which can be compromised by local or by global phenomena. However, the relevance of local and global phenomena has rarely been investigated simultaneously. Here we tested whether local phenomena compromised a species’ demographic trend using the Eurasian common lizard Zootoca vivipara, the terrestrial reptile exhibiting the widest geographic distribution, as a model species. We analysed the species’ ancient demographic trend using genetic data from its six allopatric genetic clades and tested whether its demographic trend mainly depended on single clades or on global phenomena. Zootoca vivipara’s effective population size increased since 2.3 million years ago and started to increase steeply and continuously from 0.531 Mya. Population growth rate exhibited two maxima, both occurring during global climatic changes and important vegetation changes on the northern hemisphere. Effective population size and growth rate were negatively correlated with global surface temperatures, in line with global parameters driving long-term demographic trends. Zootoca vivipara’s ancient demography was not driven by a single clade, nor by the two clades that colonized huge geographic areas after the last glaciation. The low importance of local phenomena, suggests that the experimentally demonstrated high sensitivity of this species to short-term ecological changes is a response in order to cope with short-term and local changes. This suggests that what affected its long-term demographic trend the most, were not these local changes/responses, but rather the important and prolonged global climatic changes and important vegetation changes on the northern hemisphere, including the opening up of the forest by humans.

Associations across time: The hippocampus as a temporary memory store

1985 ◽  
Vol 8 (3) ◽  
pp. 479-497 ◽  
Author(s):  
J. N. P. Rawlins
Keyword(s):  
High Capacity ◽  
Hippocampal Damage ◽  
Limited Capacity ◽  
Short Term ◽  
Long Term Storage ◽  
Memory Store ◽  
Complementary Set ◽  
Temporary Memory ◽  
Term Storage

AbstractAll recent memory theories of hippocampal function have incorporated the idea that the hippocampus is required to process items only of some qualitatively specifiahle kind, and is not required to process items of some complementary set. In contrast, it is now proposed that the hippocampus is needed to process stimuli of all kinds, but only when there is a need to associate those stimuli with other events that are temporally discontiguous. In order to form or use temporally discontiguous associations, it is essential to maintain some memory of the first component until the second component has occurred. When the temporal gap to he spanned is small, and the number of items to be temporarily retained is low, a limited-capacity, short-term store is sufficient to allow associations to be formed. Such a store is presumed to operate in parallel with the hippocampus in normal animals. Hippocampal damage disrupts a much higher-capacity store that has a slower decay rate, and so leaves animals with only a very limited ability to form temporally discontiguous associations. Hippocampal damage, however, is not held to affect the long-term storage of associations of any kind, if they can be formed. Analyses of both new and existing data are presented to show that by classifying tasks in terms of the need to use a temporary memory store to retain temporally discontiguous information one can cut right across existing classifications as well as achieve a better fit to the data. The hippocampus thus seems best described as a high-capacity, intermediate-term memory store.

Treatment-naïve quiescent macular neovascularization secondary to AMD: The 2019 Young Investigator Lecture of Macula Society

2021 ◽  
pp. 112067212098637
Author(s):  
Giuseppe Querques ◽  
Riccardo Sacconi ◽  
Vittorio Capuano ◽  
Adriano Carnevali ◽  
Donato Colantuono ◽  
...  
Keyword(s):  
Growth Rate ◽  
Short Term ◽  
Macular Disease ◽  
Age Related ◽  
Treatment Naïve ◽  
Ordinary Type ◽  
Perfusion Density

Purpose: To analyze different clinical and anatomical features in treatment-naïve non-exudative macular neovascularizations (MNVs) secondary to age-related macular disease (AMD). Methods: In this retrospective longitudinal study with a minimum follow-up of 1 year, 31 eyes of 28 consecutive AMD patients (mean age 75 ± 9 years) with treatment-naïve non-exudative MNV were enrolled. Patients were divided in: short-term activated MNV group (exudation before 6-month) and quiescent MNV group (per definition no exudation during a minimum 6-month follow-up) showing no or late activation during follow-up (persistently quiescent and long-term activated MNV group, respectively). Results: During the follow-up (mean duration: 22 ± 9 months) four eyes (13%) showed exudation before 6-month follow-up (short-term activated MNV group), whereas 21 eyes (68%) did not develop signs of exudation (persistently quiescent group), and six eyes (19%) developed exudation after the minimum 6-month follow-up (long-term activated MNV group). Monthly MNV growth rate was significantly higher in the short-term activated MNV group (growth rate of 13.30%/month), vs persistently quiescent MNV group (0.64%/month, p < 0.001) and long-term activated quiescent MNV group (1.07%/month, p < 0.001). Furthermore, at the baseline, perfusion density of short-term activated MNV group was significantly greater in comparison to persistently quiescent MNV group ( p = 0.001) and long-term activated MNV group ( p = 0.106). Conclusion: We reported two different patterns for subclinical MNVs: subclinical MNVs characterized by short-term activation which could represent simply a pre-exudative stage in the development of an ordinary type 1 MNV, and quiescent MNVs characterized by low rate of growth and possible long-term activation. Analysis of OCT-A features may predict short-term activation for subclinical MNV but no features could predict the long-term activation.

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