scholarly journals Colors and Some Morphological Traits as Defensive Mechanisms in Anurans

2009 ◽  
Vol 2009 ◽  
pp. 1-12 ◽  
Author(s):  
Luís Felipe Toledo ◽  
Célio F. B. Haddad
Keyword(s):  
Morphological Traits ◽  
Future Research ◽  
Defensive Strategy ◽  
Animal Groups ◽  
Defensive Strategies ◽  
Defensive Mechanisms ◽  
Behavioral Display ◽  
Defensive Mechanism

Anurans may be brightly colored or completely cryptic. Generally, in the former situation, we are dealing with aposematism, and the latter is an example of camouflage. However, these are only simple views of what such colorations really mean and which defensive strategy is implied. For instance, a brightly colored frog may be part of a mimicry ring, which could be either Batesian, Müllerian, or Browerian. These are only examples of the diversity of color-usage systems as defensive strategies. Unfortunately, reports on the use of colors as defensive mechanisms are widespread in the available literature, and the possible functions are rarely mentioned. Therefore, we reviewed the literature and added new data to this subject. Then, we the use of colors (as defensive mechanism) into categories. Mimicry was divided into the subcategories camouflage, homotypy, and nondeceitful homotypy, and these groups were also subcategorized. Dissuasive coloration was divided into behavioral display of colors, polymorphism, and polyphenism. Aposematism was treated apart, but aposematic colorations may be present in other defensive strategies. Finally, we propose functions and forms of evolution for some color systems in post-metamorphic anurans and hope that this review can be the basis for future research, even on other animal groups.

Deficiency of innate immunity against P. aeruginosa enhances behavioral avoidance via the HECW-1/NPR-1 module in C. elegans

2021 ◽  
Author(s):  
Hua Bai ◽  
Wei Zou ◽  
Wenhui Zhou ◽  
Keqin Zhang ◽  
Xiaowei Huang
Keyword(s):  
Innate Immunity ◽  
Pathogenic Bacteria ◽  
Immune Gene ◽  
Biological Processes ◽  
Defensive Strategy ◽  
C Elegans ◽  
Defensive Strategies ◽  
Behavioral Avoidance ◽  
Neuropeptide Y Receptor ◽  
G Protein Coupled

To antagonize infection of pathogenic bacteria in soil and confer increased survival, Caenorhabditis elegans employs innate immunity and behavioral avoidance synchronously as the two main defensive strategies. Although both biological processes and their individual signaling pathways have been partially elucidated, knowledge of their interrelationship remains limited. The current study reveals that deficiency of innate immunity triggered by mutation of the classic immune gene pmk-1 promotes avoidance behavior in C. elegans ; and vice versa. Restoration of pmk-1 expression using the tissue-specific promoters suggested that the functional loss of both intestinal and neuronal pmk-1 is necessary for the enhanced avoidance. Additionally, PMK-1 co-localized with the E3 ubiquitin ligase HECW-1 in OLL neurons and regulated the expressional level of the latter, which consequently affected the production of NPR-1, a G-protein-coupled receptor homologous to the mammalian neuropeptide Y receptor, in RMG neurons in a non-cell-autonomous manner. Collectively, our study illustrates, once the innate immunity is impaired when C. elegans antagonizes bacterial infection, the other defensive strategy of behavioral avoidance can be enhanced accordingly via the HECW-1/NPR-1 module, suggesting that GPCRs in neural circuits may receive the inputs from immune system and integrate those two systems for better adapting to the real-time status.

Defensive Strategy and Player Sex Impact Heart-Rate Responses During Games-Based Drills in Professional Basketball

2020 ◽  
pp. 1-7
Author(s):  
David Suárez-Iglesias ◽  
Rubén Dehesa ◽  
Aaron T. Scanlan ◽  
José A. Rodríguez-Marroyo ◽  
Alejandro Vaquera
Keyword(s):  
Heart Rate ◽  
Training Stimulus ◽  
Training Load ◽  
Defensive Strategy ◽  
Basketball Players ◽  
Professional Basketball ◽  
Defensive Strategies ◽  
Cardiovascular Stress ◽  
The Impact ◽  
And Training

Purpose: Games-based drills (GBD) are the predominant form of training stimulus prescribed to male and female basketball players. Despite being readily manipulated during GBD, the impact of defensive strategy on the sex-specific demands of GBD remains unknown. Therefore, the aim of this study was to quantify and compare the heart-rate (HR) responses experienced during 5v5 GBD using different defensive strategies (man-to-man defense vs zone defense [ZD] formations) according to player sex. Method: HR was recorded in 11 professional male and 10 professional female basketball players while performing 5v5 GBD with different defensive strategies (man-to-man defense or ZD). HR-based training load was also calculated using the summated heart-rate zones model. Results: During man-to-man defense, mean HR (), relative time (in percentage) spent working at 90% to 100% maximal HR (), and summated heart-rate zones () were greater (P < .05) in female players compared with males. During ZD, higher (P < .01) peak HR (), mean HR (), relative and absolute (in minutes) time spent working at 80% to 89% maximal HR ( and .03, respectively) and 90% to 100% maximal HR ( and .09, respectively), and summated heart-rate zones () were observed in female players compared with males. Conclusions: The defensive strategy employed during 5v5 full-court GBD influences HR responses and training load differently according to sex, where female players experience higher HR responses than males, especially when ZD are adopted. Basketball coaching staff can use these findings for the precise manipulation of team defenses during GBD to elicit desired cardiovascular stress on players.

Population diet variation and individual specialization in the poison toad, Melanophryniscus rubriventris (Vellard, 1947)

2011 ◽  
Vol 32 (2) ◽  
pp. 261-265 ◽  
Author(s):  
María Fernanda Quiroga ◽  
Marcos Vaira ◽  
Maria Ines Bonansea
Keyword(s):  
Entire Range ◽  
Diet Composition ◽  
Foraging Strategies ◽  
Future Research ◽  
Individual Specialization ◽  
Generalist Species ◽  
Defensive Strategies ◽  
Important Prey ◽  
Diet Variation ◽  
Prey Items

AbstractFew studies have investigated the level of individual variation in diet composition of poisonous frogs and toads. We compare the diet composition of three populations of a poisonous toad, Melanophryniscus rubriventris, and predicted that toads within a population might be constrained to forage on particular types of alkaloid-containing prey and consequently diets among populations might not diverge from each other. Most important prey categories in the diets of the three populations consisted of the same ground-dwelling arthropods. We found evidence for individuals consuming different arrays of prey types in all populations implying that this “generalist” species is actually comprised of individuals eating different sets of the available range of prey. Formicidae, Acari, and Coleoptera were all important alkaloid-containing prey items in the diets of all populations and individuals, although there were differences in their order of importance among populations and individuals use different sets of the entire range of alkaloid-containing preys. Future research should evaluate individual diet variation in other poisonous anurans taxa given that shifts in diet composition might have important implications for understanding the consequences of alternate foraging strategies in the evolution of defensive strategies among species.

scholarly journals The influence of morphological variation on migration performance in a trans-hemispheric migratory songbird

2015 ◽  
Vol 2 (1) ◽  
pp. 86-95 ◽  
Author(s):  
Lawrence Lam ◽  
Emily A. McKinnon ◽  
James D. Ray ◽  
Myrna Pearman ◽  
Glen T. Hvenegaard ◽  
...  
Keyword(s):  
Body Size ◽  
Morphological Traits ◽  
Light Level ◽  
Spring Migration ◽  
Future Research ◽  
Long Distance ◽  
Intrinsic Factors ◽  
Migratory Songbirds ◽  
Migratory Songbird ◽  
Direct Tracking

AbstractFor long-distance migratory songbirds, morphological traits such as longer wings and a smaller body size are predicted to increase migration efficiency. Due to previous limitations in our ability to track the long-distance journeys of small-bodied birds, the relationship between morphology and start-to-finish migration performance has never been fully tested in free-living songbirds. Using direct-tracking data obtained from light-level geolocators, we examined the effects of morphological factors (wing and body size) on spring and fall migration performance (flight speed, duration of stopovers, total stopovers taken) of a widely distributed, trans-hemispheric migratory songbird, the purple martin (Progne subis) (n = 120). We found that smaller-bodied birds spent fewer days at stopovers along fall migration, but larger-bodied birds spent fewer days at stopover and took fewer stopovers during spring migration. More of the variation in fall migration performance was explained by morphology, as compared to spring migration, possibly indicating a larger influence of environmental conditions on spring performance. Overall, our results partially support long-standing and previously untested predictions regarding the influence of intrinsic factors on migration performance. Future research should examine the influence of environmental variation on migration performance as well as additional morphological traits that may contribute to migration performance.

scholarly journals Identifying morphological traits associated with vegetative persistence in the perennial ryegrass (Lolium perenne L.) cultivar 'Grasslands Samson'

2020 ◽  
Vol 82 ◽  
pp. 139-147
Author(s):  
Jessica R. O'Connor ◽  
James R. Crush ◽  
Zulfi Jahufer
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Morphological Traits ◽  
Genotypic Variation ◽  
Dry Weight ◽  
Tiller Number ◽  
Future Research ◽  
Lolium Perenne L ◽  
Genetic Shift

Perennial ryegrass (Lolium perenne L.) vegetative persistence (maintained herbage growth and survival without reseeding) is an important economic trait for farmers in New Zealand as it decreases the frequency of reseeding pastures. Vegetative persistence is difficult to breed for due to a lack of long-term trials to observe the complex interactions between plant genotype and the environment. In a long-term trial a genetic shift in the sown cultivar population could occur as individual plants with advantageous traits outcompete other plants and survive. The objectives of our study were to investigate the occurrence of a potential genetic shift in a sample (30 plants) of a persistent population of ‘Grasslands Samson’ perennial ryegrass. Persistent plants were collected from a nine-year-old trial at Poukawa, Hawke's Bay. To identify a genetic shift, these plants were compared to a sample of 30 plants sourced from commercial seed of ‘Grasslands Samson’ representing the original population. This study estimated genotypic variation within and between the populations for eight morphological traits after 10 weeks' growth under glasshouse conditions. Phenotypic and genotypic correlations between the traits were estimated. Results showed that the persistent population had significantly (P<0.05) greater means for tiller number, reproductive tiller number, lamina sheath length, and dry weight. Future research studying these traits across farm environments would further understanding of their roles in vegetative persistence of ryegrass.

scholarly journals Use of Machine Learning to Automate the Identification of Basketball Strategies Using Whole Team Player Tracking Data

2019 ◽  
Vol 10 (1) ◽  
pp. 24 ◽  
Author(s):  
Changjia Tian ◽  
Varuna De Silva ◽  
Michael Caine ◽  
Steve Swanson
Keyword(s):  
Machine Learning ◽  
Team Sports ◽  
Classification Model ◽  
Machine Learning Techniques ◽  
Tracking Data ◽  
Defensive Strategy ◽  
Defensive Strategies ◽  
Player Tracking ◽  
Ball Tracking ◽  
The One

The use of machine learning to identify and classify offensive and defensive strategies in team sports through spatio-temporal tracking data has received significant interest recently in the literature and the global sport industry. This paper focuses on data-driven defensive strategy learning in basketball. Most research to date on basketball strategy learning has focused on offensive effectiveness and is based on the interaction between the on-ball player and principle on-ball defender, thereby ignoring the contribution of the remaining players. Furthermore, most sports analytical systems that provide play-by-play data is heavily biased towards offensive metrics such as passes, dribbles, and shots. The aim of the current study was to use machine learning to classify the different defensive strategies basketball players adopt when deviating from their initial defensive action. An analytical model was developed to recognise the one-on-one (matched) relationships of the players, which is utilised to automatically identify any change of defensive strategy. A classification model is developed based on a player and ball tracking dataset from National Basketball Association (NBA) game play to classify the adopted defensive strategy against pick-and-roll play. The methodology described is the first to analyse the defensive strategy of all in-game players (both on-ball players and off-ball players). The cross-validation results indicate that the proposed technique for automatic defensive strategy identification can achieve up to 69% accuracy of classification. Machine learning techniques, such as the one adopted here, have the potential to enable a deeper understanding of player decision making and defensive game strategies in basketball and other sports, by leveraging the player and ball tracking data.

Kepelbagaian Sumber Genetik Padi di Bank Gen Padi MARDI Seberang Perai

2014 ◽  
Vol 70 (6) ◽  
Author(s):  
Site Noorzuraini Abd Rahman ◽  
Mohd Shukri Mat Ali ◽  
Ismail Muhamod Nor ◽  
Latefi Mahmud ◽  
Fauziah Shafie
Keyword(s):  
Food Supply ◽  
Morphological Traits ◽  
Rice Variety ◽  
Breeding Program ◽  
Future Research ◽  
Rice Varieties ◽  
Breeding Lines ◽  
Collaboration Project ◽  
Traditional Rice

Rice Genebank located in MARDI Seberang Perai was the first seeds bank in Malaysia which was established in year 1989 with the objective for conserving the diversity of Malaysian rice germplasms from extinction and for utilization in future research and breeding program. The germplasms were gathered through collection expeditions in entire Malaysia, while the foreign seed varieties were gathered through collaboration project involved seeds exchange. Until now, a total of 12,258 accessions of rice are conserved in this Genebank comprised of 32% of traditional rice varieties, 35.7% of released rice varieties and breeding lines developed by MARDI and the remaining are consisted of introduced rice varieties. This study observed the rice accessions conserved in the genebank are highly variability. Several morphological traits of rice also shown highly significant correlations between traits; thus this finding is important for research and variety development for produce new high-yielding rice variety for accommodate the national food supply. 

scholarly journals If you are not prepared to be wrong, then your self-serving biases are simply not enough. Relationships between self-serving biases and discrepant self-esteem.

2020 ◽  
Author(s):  
Cristina Zogmaister ◽  
Laurentiu Maricutoiu
Keyword(s):  
Self Esteem ◽  
Defensive Strategies ◽  
Growing Body ◽  
Defensive Mechanisms ◽  
Implicit And Explicit ◽  
The Relationship

Previous research has demonstrated that individuals with discrepant (fragile: high explicit and low implicit, or damaged: high implicit and low explicit) self-esteem are more likely to engage in defensive mechanisms than individuals with consistent implicit and explicit self-esteem. With two studies, we investigated the relationship between implicit and explicit self-esteem, and three defensive strategies for the threat of failure: subjective overachievement, psychological disengagement, and retroactive excuses. In Study 1 (N = 176), fragile self-esteem was associated with subjective overachievement, and low implicit self-esteem was associated with psychological disengagement. In Study 2 (N = 101), damaged self-esteem was related to increased use of retroactive excuses as a form of self-serving bias. These results add to the growing body of evidence documenting the maladaptive nature of fragile and damaged self-esteem.

scholarly journals Hostile Takeover Bids: Defensive Strategies

2000 ◽  
Vol 38 (1) ◽  
pp. 111
Author(s):  
Richard A. Shaw
Keyword(s):  
Board Of Directors ◽  
Chief Executive Officer ◽  
Oil And Gas ◽  
Chief Executive ◽  
Hostile Takeover ◽  
Special Committee ◽  
Defensive Strategy ◽  
Defensive Strategies ◽  
Takeover Bids ◽  
Oil And Gas Companies

This article, after noting that many oil and gas companies are vulnerable to takeovers and that merger transactions are reaching record-breaking dollar volumes, examines and recommends steps that a corporation may take when facing a hostile takeover bid. These steps are defensive strategies that a chief executive officer, a board of directors, and other players should consider implementing when handling a merger. Recommended strategies for a corporation facing a takeover situation include creating a special committee, choosing appropriate financial and legal advisors, establishing a data room, and seeking other potential buyers. The author concludes that a successful defensive strategy can maximize value for a corporation's shareholders.

scholarly journals EAU ET CHANGEMENT CLIMATIQUE : QUELLES STRATÉGIES D’ADAPTATION POUR LA GESTION DE L’EAU D’IRRIGATION DANS LE SUD-EST TUNISIEN

New Medit ◽  
2019 ◽  
Vol 18 (1) ◽  
pp. 15-28
Author(s):  
Naceur Mahdhi ◽  
Mongi Sghaier ◽  
Ayoub Fouzai ◽  
Nesrine Kadri
Keyword(s):  
Climate Change ◽  
Production Systems ◽  
Groundwater Resources ◽  
Winter Season ◽  
Cropping System ◽  
Adaptation Strategies ◽  
Economic Returns ◽  
Defensive Strategy ◽  
Adaptation Measures ◽  
Defensive Strategies

The objective of this study was to identify the different irrigators’ strategies and to analyze the economic profitability of irrigated production systems in relation to adaptations to the scarcity of groundwater resources in a context of climate change in the South east of Tunisian. Based on surveys of 190 irrigated farms, this research shows that eighty-five percent (85%) of respondents clearly perceive climate change in southeastern Tunisia. These changes result in a decrease and an increasing irregularity of the rains, a disruption of the winter season, a greater frequency of pockets of drought and the decrease of the piezometric level of the water tables. In response to these changes, irrigators have adopted adaptation strategies, the most common of which are: offensive strategy or “chasing”, defensive strategy and contractive strategy. These strategies include various adaptation measures such as annual cleaning and deepening of wells, the use of water saving, the change of the cropping system and the reduction of irrigated area. These readjustments for most of the measures adopted by the irrigators have an impact on the elements of their operating account. In addition, offensive and defensive strategies appear to be the most economically profitable types of adaptation at the 1% level. Knowledge of different adaptation strategies and their economic returns enables adaptation options to be identified that are both realistic in terms of implementation and ambitious in terms of their objectives, and help develop priorities for adaptation of water resources for irrigation.

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