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2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Juan Lorite ◽  
Carlos Salazar-Mendías ◽  
Roza Pawlak ◽  
Eva María Cañadas

AbstractOvergrazing stands out as threat factors on biodiversity, being especially harmful in the Mediterranean, due to strong human pressure and an accelerated climate change acting synergistically. Fencing is a common tool used in conservation biology to tackle this problem. Advantages of fences are usually fast, intuitive, and easy to evaluate. However, disadvantages could also arise (increasing interspecific competition, disturbing habitat structure, limiting pollination, reducing dispersion). Together with management issues (maintenance, conflicts with stakeholders, and pulling effect). Effectiveness of fencing for conservation has been frequently assessed for animals, while it is almost a neglected topic in plants. We evaluated the outcome of fencing three threatened and narrow-endemic plants. Selected 5 populations were only partly fenced, which allowed comparing different variables inside and outside the fence. For evaluating the fencing effects, we sampled several habitats (vegetation cover, composition, density of target species), and target-species features (individual size, neighbouring species, and fruit-set). Fencing had strong effects on the habitat and on target-species individuals, showing contrasting responses at species and population level. Particularly, for Erodium cazorlanum, fence had a positive effect in one case, and negative in another. In Hormathophylla baetica effect was positive in all populations. Finally, fencing negatively affected Solenanthus reverchonii by increasing competition and limiting seed-dispersal. Fencing outcome was different in assessed species, highlighting the need to a case-by-case evaluation to determine the net balance (pros vs. cons), also its suitability and most favourable option (i.e. permanent vs. temporary fences).


2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Anna Runge ◽  
Jerzy Runge

The study aims to present variability in the population of individual size classes of Polish cities in 1950-2018, its determinants and consequences for the formation of the settlement system. The application of quartiles as the basic statistical measure allowed identifying which parts of particular size classes of cities had the greatest impact (progressively or regressively) on changes in the settlement system. In this respect, strong dynamics of the upper quartile of Polish cities, lasting until the end of the 1970s, becomes apparent. In the 1980s, the dynamics of the upper quartile of large cities showed a shift during development waves in comparison to the culmination of these waves for medium-sized cities. However, since the end of the 1980s, there has been an increasing role of the lower quartile in determining the direction of changes in the size structure of cities, especially in medium and small cities.


2021 ◽  
Author(s):  
Juan Lorite ◽  
Carlos Salazar-Mendías ◽  
Roza Pawlak ◽  
Eva Cañadas

Abstract Overgrazing stands out as threat factors on biodiversity, being especially harmful in the Mediterranean, due to strong human pressure and an accelerated climate change acting synergistically. Fencing is one of the most used tools in conservation biology to tackle this problem. Advantages of fences are usually fast, intuitive, and easy to evaluate. However, disadvantages could also arise (increasing interspecific competition, disturbing habitat structure, limiting pollination, reducing dispersion). Together with management issues (maintenance, conflicts with stakeholders, and pulling effect). Effectiveness of fencing for conservation has been frequently assessed for animals, while it is almost a neglected topic in plants. We evaluated the outcome of fencing three threatened and narrow-endemic plants. Selected 5 populations were only partly fenced, which allowed comparing different variables inside and outside the fence. For evaluating the fencing effects, we sampled several habitats (vegetation cover, composition, density of target species), and target-species features (individual size, neighbouring species, and fruit-set). Fencing had strong effects on the habitat and on target-species individuals, showing contrasting responses at species and population level. Particularly, for Erodium cazorlanum, fence had a positive effect in one case, and negative in another. In Hormathophylla baetica effect was positive in all populations. Finally, fencing negatively affected Solenanthus reverchonii by increasing competition and limiting seed-dispersal. Fencing outcome was different in assessed species, highlighting the need to a case-by-case evaluation to determine the net balance (pros vs. cons), also its suitability and most favourable option (i.e. permanent vs. temporary fences).


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Antonio Bode ◽  
M. Pilar Olivar ◽  
Santiago Hernández-León

AbstractThe importance of microbes for the functioning of oceanic food webs is well established, but their relevance for top consumers is still poorly appreciated. Large differences in individual size, and consequently in growth rates and the relevant spatial and temporal scales involved, make the integration of microorganisms and large metazoans in a common food web framework difficult. Using stable isotopes, this study estimated the trophic position of 13 species of micronektonic fishes to examine the microbial and metazoan contribution to mid trophic level consumers. Vertically migrant species displayed higher trophic positions than non-migrant species in all depth layers. The estimated trophic positions agreed well with those from the literature, but all species displayed mean increases between 0.5 and 0.8 trophic positions when taking into account microbial trophic steps. Trophic position, but not the relative importance of the microbial food web, increased with individual size, suggesting that current estimates of the trophic position of top consumers and of the length of oceanic food webs are too low because they are based only on metazoan trophic steps. This finding calls for a review of trophic position estimates and of the efficiency of trophic transfers along oceanic food webs.


Author(s):  
Marcus Lindskog ◽  
Leo Poom ◽  
Anders Winman

AbstractPervasive congruency effects characterize approximate number discrimination tasks. Performance is better on congruent (the more numerous stimulus consists of objects of larger size that occupy a larger area) than on incongruent (where the opposite holds) items. The congruency effects typically occur when controlling for nonnumeric variables such as cumulative area. Furthermore, only performance on incongruent stimuli seems to predict math abilities. Here, we present evidence for an attentional-bias induced by stimulus control (ABC) where preattentive features such as item size reflexively influence decisions, which can explain these congruency effects. In three experiments, we tested predictions derived from the ABC. In Experiment 1, as predicted, we found that manipulation of size introduced congruency effects and eliminated the correlation with math ability for congruent items. However, performance on incongruent items and neutral, nonmanipulated items were still predictive of math ability. A negative correlation between performance on congruent and incongruent items even indicated that they measure different underlying constructs. Experiment 2 demonstrated, in line with the ABC account, that increasing presentation time reduced congruency effects. By directly measuring overt attention using eye-tracking, Experiment 3 revealed that people direct their first gaze toward the array with items of larger individual size, biasing them towards these arrays. The ABC explains why the relation between performance on approximate number discrimination tasks and math achievement has been fragile and suggests that stimulus control manipulations have contaminated the results. We discuss the importance of using stimuli that are representative of the environment.


PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244884
Author(s):  
Julien Leider ◽  
Yu Li ◽  
Lisa M. Powell

Introduction Taxes on sugar-sweetened beverages (SSBs) have gained support as a policy response to adverse health effects associated with SSB consumption. On July 1, 2017, Oakland, California, implemented a one-cent/ounce tax on SSBs with ≥25 calories/12 fluid ounces. This study estimated the long-term impact of the tax on taxed and untaxed beverage prices. Methods Data on 5,830 taxed and 5,146 untaxed beverage prices were obtained from 99 stores in Oakland and 111 stores in Sacramento (comparison site), California, in late May-June 2017 and June 2019. Linear regression difference-in-differences models were computed with store and product fixed effects, with robust standard errors clustered on store, weighted based on volume sold by beverage sweetener status, type, and size. Results Taxed beverage prices increased by 0.73 cents/ounce (95% CI = 0.47,1.00) on average in supermarkets and grocery stores in Oakland relative to Sacramento and 0.74 cents/ounce (95% CI = 0.39,1.09) in pharmacies, but did not change in convenience stores (-0.09 cents/ounce, 95% CI = -0.56,0.39). Untaxed beverage prices overall increased by 0.40 cents/ounce (95% CI = 0.05,0.75) in pharmacies but did not change in other store types. Prices of taxed individual-size soda specifically increased in all store types, by 0.91–2.39 cents/ounce (p<0.05), as did prices of untaxed individual-size soda in convenience stores (0.79 cents/ounce, 95% CI = 0.01,1.56) and pharmacies (1.66 cents/ounce, 95% CI = 0.09,3.23). Conclusions Two years following SSB tax implementation, there was partial tax pass-through with differences by store type and by beverage type and size within store type.


Author(s):  
Juraj Tej ◽  
Roman Vavrek ◽  
Viera Papcunová

The role of local self-government is to increase the quality of life of inhabitants while respecting the principles of sustainable development and at the same time to ensure the adequacy, availability and quality of public services provided in its territory. The current structure of local self-government in the conditions of Slovakia clearly points to the differences between municipalities, which is illustrated by their different number in individual size categories, although they have the same competencies. Cities and municipalities in the conditions of Slovakia to provide original and transferred competencies mostly independently, but especially in the field of performance of the transferred state administration they enter into mutual cooperation. We evaluated the types of inter-municipal cooperation within two basic groups of inter-municipal cooperation - the traditional forms of cooperation and innovative forms of cooperation. The analysis showed that in the conditions of Slovakia, the most traditional way of inter-municipal cooperation is represented by joint municipal offices. We have also identified innovative approaches in the field of inter-municipal cooperation - such as agreement on shared services, co-ownership´s agency or the SMART cities concept. Such a new inter-municipal cooperation can thus be an important and beneficial change, which can help solve problems arising from the suboptimal size of individual municipalities.


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