Competition Intensity along a Productivity Gradient in a Low‐Diversity Grassland

1998 ◽  
Vol 151 (5) ◽  
pp. 465-476 ◽  
Author(s):  
Duane A. Peltzer ◽  
Scott D. Wilson ◽  
Ann K. Gerry
Keyword(s):  
Competition Intensity ◽  
Productivity Gradient ◽  
Low Diversity

Assessing competition intensity along productivity gradients using a simple model

2001 ◽  
Vol 79 (12) ◽  
pp. 1486-1491 ◽  
Author(s):  
Ken Arii ◽  
Roy Turkington
Keyword(s):  
Simple Model ◽  
Resource Availability ◽  
Plant Ecology ◽  
Competition Intensity ◽  
Productivity Gradient ◽  
Surface Variation ◽  
Intensity Changes ◽  
Productivity Gradients ◽  
Resource Levels ◽  
Theory Competition

One of the most highly debated issues in plant ecology has been the manner in which competition intensity changes along productivity gradients. We have used a simple model to attempt to demonstrate that in theory, competition intensity can vary quite considerably along productivity gradients. Our model incorporates three key components: (i) changes in resource availability along a productivity gradient, (ii) changes in resource availability when neighbours are removed, and (iii) growth characteristics of the target species and (or) individuals to varying resource levels (i.e., response surface). Variation and interactions among these three components can potentially give rise to various, and occasionally complex, changes in competition intensity along productivity gradients. This partly explains the divergent, and sometimes contradictory, results reported in previous studies.Key words: competition intensity, productivity gradient, nutrient, light, model.

Recent Rapid Climate Changes in Antarctic and their Influence on Low Diversity Ecosystems

2010 ◽  
Vol 17 (1) ◽  
pp. 17-30 ◽  
Author(s):  
Katarzyna J. Chwedorzewska
Keyword(s):  
Environmental Variables ◽  
Climate Changes ◽  
Biological Significance ◽  
Global Changes ◽  
Factors Affecting ◽  
Low Diversity ◽  
Main Factors ◽  
The Antarctic ◽  
High Diversity ◽  
Temperature Water

ABSTRACTThe geographic position, astronomic factors (e.g. the Earth’s maximum distance from the Sun during winter), ice cover and altitude are the main factors affecting the climate of the Antarctic, which is the coldest place on Earth. Parts of Antarctica are facing the most rapid rates of anthropogenic climate change currently seen on the planet. Climate changes are occurring throughout Antarctica, affecting three major groups of environmental variables of considerable biological significance: temperature, water, UV-B radiation.Low diversity ecosystems are expected to be more vulnerable to global changes than high diversity ecosystems

Lithostratigraphy of the Kweekvlei Formation (Witteberg Group), Cape Supergroup

2017 ◽  
Vol 120 (3) ◽  
pp. 421-432 ◽  
Author(s):  
C. Browning ◽  
M. Reid
Keyword(s):  
South Africa ◽  
Transition Zone ◽  
Distal Part ◽  
Vascular Plant ◽  
Trace Fossil ◽  
Plant Debris ◽  
Lower Carboniferous ◽  
Fossil Assemblage ◽  
Low Diversity ◽  
Storm Wave

AbstractThe Lower Carboniferous, probably Tournaisian, Kweekvlei Formation is part of the Witteberg Group (Cape Supergroup) of South Africa. Together with the overlying Floriskraal Formation, it forms an upward-coarsening succession within the Lake Mentz Subgroup. Sedimentary features of the Kweekvlei Formation suggest deposition in a storm-wave dominated marine setting, within the storm-influenced, distal part of an offshore transition zone environment. This predominantly argillaceous formation preserves a low diversity trace fossil assemblage. Reworked vascular plant debris (including the problematic genus Praeramunculus sp.) and a shark spine have been reported for the Kweekvlei Formation. There are no known stratigraphic equivalents in South Africa.

The Effect of Competition Intensity and Competition Type on the Use of Customer Satisfaction Measures in Executive Annual Bonus Contracts

2014 ◽  
Vol 90 (1) ◽  
pp. 229-263 ◽  
Author(s):  
Clara Xiaoling Chen ◽  
Ella Mae Matsumura ◽  
Jae Yong Shin ◽  
Steve Yu-Ching Wu
Keyword(s):  
Customer Satisfaction ◽  
Interactive Effect ◽  
Joint Effect ◽  
Performance Measure ◽  
Two Dimensions ◽  
Data Availability ◽  
Competition Intensity ◽  
Nonfinancial Performance ◽  
Alternative Measures ◽  
Satisfaction Measures

ABSTRACT This paper empirically examines the interactive effect of competition intensity and competition type on the use of customer satisfaction measures in executives' annual bonus contracts. Specifically, we predict a stronger association between competition intensity in an industry and the use of customer satisfaction measures in executives' annual bonus contracts when the competition is non-price-based than when the competition is price-based. Using hand-collected data from Standard & Poor's (S&P) 1500 firms' disclosures of the use of customer satisfaction measures in executive bonus contracts in 2006 and 2010 proxy statements, we find results consistent with our prediction. Our results are robust to alternative measures of competition type and competition intensity. We also find similar results when we use the weight on customer satisfaction measures in executive bonus contracts as the dependent variable. Our study extends the literature on the effect of competition on the design of managerial incentives by distinguishing between competition intensity and competition type, and providing the first large-sample empirical evidence on the joint effect of these two dimensions of competition on the incentive use of an important nonfinancial performance measure. Data Availability: Data used in this study are obtained from publicly available sources.

scholarly journals Genomic Characterization of the Three Balkan Livestock Guardian Dogs

2021 ◽  
Vol 13 (4) ◽  
pp. 2289
Author(s):  
Mateja Janeš ◽  
Minja Zorc ◽  
Maja Ferenčaković ◽  
Ino Curik ◽  
Peter Dovč ◽  
...  
Keyword(s):  
Conservation Management ◽  
Diversity Management ◽  
Genomic Diversity ◽  
Mountainous Areas ◽  
Autosomal Snps ◽  
The Balkans ◽  
Gray Wolves ◽  
Low Diversity ◽  
Genomic Characterization

Balkan Livestock Guardian Dogs (LGD) were bred to help protect sheep flocks in sparsely populated, remote mountainous areas in the Balkans. The aim of this study was genomic characterization (107,403 autosomal SNPs) of the three LGD breeds from the Balkans (Karst Shepherd, Sharplanina Dog, and Tornjak). Our analyses were performed on 44 dogs representing three Balkan LGD breeds, as well as on 79 publicly available genotypes representing eight other LGD breeds, 70 individuals representing seven popular breeds, and 18 gray wolves. The results of multivariate, phylogenetic, clustering (STRUCTURE), and FST differentiation analyses showed that the three Balkan LGD breeds are genetically distinct populations. While the Sharplanina Dog and Tornjak are closely related to other LGD breeds, the Karst Shepherd is a slightly genetically distinct population with estimated influence from German Shepard (Treemix analysis). Estimated genomic diversity was high with low inbreeding in Sharplanina Dog (Ho = 0.315, He = 0.315, and FROH>2Mb = 0.020) and Tornjak (Ho = 0.301, He = 0.301, and FROH>2Mb = 0.033) breeds. Low diversity and high inbreeding were estimated in Karst Shepherds (Ho = 0.241, He = 0.222, and FROH>2Mb = 0.087), indicating the need for proper diversity management. The obtained results will help in the conservation management of Balkan LGD dogs as an essential part of the specific grazing biocultural system and its sustainable maintenance.

scholarly journals Information Acquisition and Its Incentives in an E-Commerce Supply Chain under the Offline Showroom Model

2021 ◽  
Vol 16 (5) ◽  
pp. 1791-1804
Author(s):  
Mengli Li ◽  
Xumei Zhang
Keyword(s):  
Supply Chain ◽  
Information Acquisition ◽  
Incentive Contracts ◽  
Demand Forecast ◽  
Competition Intensity ◽  
Demand Information ◽  
Optimal Information ◽  
Acquisition Strategy ◽  
The One ◽  
The Impact

Recently, the showroom model has developed fast for allowing consumers to evaluate a product offline and then buy it online. This paper aims at exploring the optimal information acquisition strategy and its incentive contracts in an e-commerce supply chain with two competing e-tailers and an offline showroom. Based on signaling game theory, we build a mathematical model by considering the impact of experience service and competition intensity on consumers’ demand. We find that, on the one hand, information acquisition promotes supply chain members to obtain demand information directly or indirectly, which leads to forecast revenue. On the other hand, information acquisition promotes supply chain members to distort optimal decisions, which results in signal cost. The optimal information acquisition strategy depends on the joint impact of forecast revenue, signal cost and demand forecast cost. Notably, in some conditions, the offline showroom will not acquire demand information even when its cost is equal to zero. We also design two different information acquisition incentive contracts to obtain Pareto improvement for all supply chain members.

scholarly journals Biopolymeric Materials Used as Nonviral Vectors: A Review

2021 ◽  
Vol 2 (1) ◽  
pp. 100-109
Author(s):  
Jailson de Araújo Santos ◽  
Daniel Barbosa Liarte ◽  
Alessandra Braga Ribeiro ◽  
Marcia dos Santos Rizzo ◽  
Marcília Pinheiro da Costa ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Web Of Science ◽  
Gene Transfection ◽  
Genetic Material ◽  
Nonviral Vectors ◽  
Cationic Polymers ◽  
Genetic Trait ◽  
Low Diversity ◽  
Different Types ◽  
Materials Used

Bacterial transformation and gene transfection can be understood as being the results of introducing specific genetic material into cells, resulting in gene expression, and adding a new genetic trait to the host cell. Many studies have been carried out to investigate different types of lipids and cationic polymers as promising nonviral vectors for DNA transfer. The present study aimed to carry out a systematic review on the use of biopolymeric materials as nonviral vectors. The methodology was carried out based on searches of scientific articles and applications for patents published or deposited from 2006 to 2020 in different databases for patents (EPO, USPTO, and INPI) and articles (Scopus, Web of Science, and Scielo). The results showed that there are some deposits of patents regarding the use of chitosan as a gene carrier. The 16 analyzed articles allowed us to infer that the use of biopolymers as nonviral vectors is limited due to the low diversity of biopolymers used for these purposes. It was also observed that the use of different materials as nonviral vectors is based on chemical structure modifications of the material, mainly by the addition of cationic groups. Thus, the use of biopolymers as nonviral vectors is still limited to only a few polysaccharide types, emphasizing the need for further studies involving the use of different biopolymers in processes of gene transfer.

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