scholarly journals Trade-off between carotenoid-based sexual ornamentation and sperm resistance to oxidative challenge

2017 ◽  
Vol 284 (1847) ◽  
pp. 20162444 ◽  
Author(s):  
Oldřich Tomášek ◽  
Jana Albrechtová ◽  
Martina Němcová ◽  
Pavlína Opatová ◽  
Tomáš Albrecht
Keyword(s):  
Redox Homeostasis ◽  
Sperm Velocity ◽  
Trade Off ◽  
Competition Theory ◽  
Oxidative Challenge ◽  
Sperm Midpiece ◽  
Sperm Morphometry ◽  
Sexual Ornamentation ◽  
Sperm Traits

It has been hypothesized that carotenoid-based sexual ornamentation signals male fertility and sperm competitive ability as both ornamentation and sperm traits may be co-affected by oxidative stress, resulting in positive covariation (the ‘redox-based phenotype-linked fertility hypothesis’; redox-based PLFH). On the other hand, the ‘sperm competition theory’ (SCT) predicts a trade-off between precopulatory and postcopulatory traits. Here, we manipulate oxidative status (using diquat dibromide) and carotenoid availability in adult zebra finch ( Taeniopygia guttata ) males in order to test whether carotenoid-based beak ornamentation signals, or is traded off against, sperm resistance to oxidative challenge. Initial beak colouration, but not its change during the experiment, was associated with effect of oxidative challenge on sperm velocity, such that more intense colouration predicted an increase in sperm velocity under control conditions but a decline under oxidative challenge. This suggests a long-term trade-off between ornament expression and sperm resistance to oxidative challenge. Shortening of the sperm midpiece following oxidative challenge further suggests that redox homeostasis may constrain sperm morphometry. Carotenoid supplementation resulted in fewer sperm abnormalities but had no effect on other sperm traits. Overall, our data challenge the redox-based PLFH, partially support the SCT and highlight the importance of carotenoids for normal sperm morphology.

scholarly journals Pre- and post-copulatory traits working in concert: sexual dichromatism in passerines is associated with sperm morphology

2020 ◽  
Vol 16 (1) ◽  
pp. 20190568
Author(s):  
Kate L. Durrant ◽  
Tom Reader ◽  
Matthew R. E. Symonds
Keyword(s):  
Sexual Selection ◽  
Sexual Dichromatism ◽  
Trade Off ◽  
Male Plumage ◽  
Negative Trait ◽  
Sperm Midpiece ◽  
Costly Traits ◽  
Phylogenetic Regression ◽  
Positive Covariance ◽  
Sperm Traits

Passerine birds produce costly traits under intense sexual selection, including elaborate sexually dichromatic plumage and sperm morphologies, to compete for fertilizations. Plumage and sperm traits vary markedly among species, but it is unknown if this reflects a trade-off between pre- and post-copulatory investment under strong sexual selection producing negative trait covariance, or variation in the strength of sexual selection among species producing positive covariance. Using phylogenetic regression, we analysed datasets describing plumage and sperm morphological traits for 278 passerine species. We found a significant positive relationship between sperm midpiece length and male plumage elaboration and sexual dichromatism. We did not find a relationship between plumage elaboration and testes mass. Our results do not support a trade-off between plumage and sperm traits, but may be indicative of variance among species in the strength of sexual selection to produce both brightly coloured plumage and costly sperm traits.

The Effect of Long-Term Antioxidant Treatments on Redox Homeostasis in Clinical Studies

2007 ◽  
Vol 1 (1) ◽  
pp. 83-95
Author(s):  
Anna Blázovics ◽  
Ágota Kovács ◽  
Andrea Lugasi
Keyword(s):  
Clinical Studies ◽  
Redox Homeostasis

Long-term impact of sublethal atrazine perturbs the redox homeostasis in pea (Pisum sativum L.) plants

PROTOPLASMA ◽  
2012 ◽  
Vol 250 (1) ◽  
pp. 95-102 ◽  
Author(s):  
Sergei Ivanov ◽  
Elena Shopova ◽  
Pavel Kerchev ◽  
Iskren Sergiev ◽  
Lyuba Miteva ◽  
...  
Keyword(s):  
Pisum Sativum ◽  
Redox Homeostasis ◽  
Pisum Sativum L ◽  
Long Term Impact

scholarly journals The Effect of Acute Oral Galactose Administration on the Redox System of the Rat Small Intestine

Antioxidants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 37
Author(s):  
Jan Homolak ◽  
Ana Babic Perhoc ◽  
Ana Knezovic ◽  
Jelena Osmanovic Barilar ◽  
Davor Virag ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Small Intestine ◽  
Oral Administration ◽  
Redox Homeostasis ◽  
Intestinal Barrier ◽  
Redox System ◽  
Dissociation Rate ◽  
Term Administration ◽  
Male Wistar Rats

Galactose is a ubiquitous monosaccharide with important yet incompletely understood nutritive and physiological roles. Chronic parenteral d-galactose administration is used for modeling aging-related pathophysiological processes in rodents due to its ability to induce oxidative stress (OS). Conversely, chronic oral d-galactose administration prevents and alleviates cognitive decline in a rat model of sporadic Alzheimer’s disease, indicating that galactose may exert beneficial health effects by acting in the gut. The present aim was to explore the acute time-response of intestinal redox homeostasis following oral administration of d-galactose. Male Wistar rats were euthanized at baseline (n = 6), 30 (n = 6), 60 (n = 6), and 120 (n = 6) minutes following orogastric administration of d-galactose (200 mg/kg). The overall reductive capacity, lipid peroxidation, the concentration of low-molecular-weight thiols (LMWT) and protein sulfhydryls (SH), the activity of Mn and Cu/Zn superoxide dismutases (SOD), reduced and oxidized fractions of nicotinamide adenine dinucleotide phosphates (NADPH/NADP), and the hydrogen peroxide dissociation rate were analyzed in duodenum and ileum. Acute oral administration of d-galactose increased the activity of SODs and decreased intestinal lipid peroxidation and nucleophilic substrates (LMWT, SH, NADPH), indicating activation of peroxidative damage defense pathways. The redox system of the small intestine can acutely tolerate even high luminal concentrations of galactose (0.55 M), and oral galactose treatment is associated with a reduction rather than the increment of the intestinal OS. The ability of oral d-galactose to modulate intestinal OS should be further explored in the context of intestinal barrier maintenance, and beneficial cognitive effects associated with long-term administration of low doses of d-galactose.

Long-term Dietary Changes after Vertical Banded Gastroplasty: Is the Trade-off Favorable?

2002 ◽  
Vol 12 (6) ◽  
pp. 805-811 ◽  
Author(s):  
Iris Shai ◽  
Yaakov Henkin ◽  
Shimon Weitzman ◽  
Itzhak Levi
Keyword(s):  
Vertical Banded Gastroplasty ◽  
Trade Off ◽  
Dietary Changes ◽  
Banded Gastroplasty

Seasonal Trade-Off between Water- and Nitrogen-Use Efficiency of Constructive Plants in Desert Riparian Forest in Hyperarid Region of China

2011 ◽  
pp. 260-275
Author(s):  
Shengkui Cao ◽  
Qi Feng ◽  
Jianhua Si ◽  
Yonghong Su ◽  
Zongqiang Chang ◽  
...  
Keyword(s):  
Nitrogen Use Efficiency ◽  
Riparian Forest ◽  
Seasonal Pattern ◽  
Nitrogen Concentration ◽  
Populus Euphratica ◽  
Nitrogen Use ◽  
Trade Off ◽  
N Concentration ◽  
Use Efficiency

Foliar d13C values are often used to denote the long-term water use efficiency (WUE) of plants whereas long-term nitrogen use efficiency (NUE) are usually estimated by the ratio of C to N in the leaves. Seasonal variations of d13C values, foliar nitrogen concentration and C/N ratios of Populus euphratica and Tamarix ramosissima grown under five different microhabitats of Ejina desert riparian oasis of northwestern arid regions in China were studied. The results indicated that T. ramosissima had higher d13C value compared with that of P. euphratica. The N concentration and C/N ratios of two species were not significantly different. The seasonal pattern of three indexes in two species was different. The d13C values and N concentration decreased during the plant’s growth period. However, the change of C/N ratios was increased. Among microhabitats, there were higher d13C values and N concentration as well as lower C/N ratios in the Dune and Gobi habitats. Foliar d13C values significantly and positively correlated with N concentration in P. euphratica and T. ramosissima, whereas a significantly negative correlation between d13C values and C/N ratios was found for P. euphratica. This relation in T. ramosissima was weak, but there was a significant quadratic curve relationship between d13C values and C/N ratios, which revealed that there was a trade-off between WUE and NUE for P. euphratica and in natural condition, P. euphratica could not improve WUE and NUE simultaneously. T. ramosissima could simultaneously enhance WUE and NUE. The above characters of WUE and NUE in two plants reflected the different adaptations of desert species to environmental condition.

scholarly journals Firm Acquisitions by Family Firms: A Mixed Gamble Approach

2019 ◽  
Vol 32 (4) ◽  
pp. 354-377 ◽  
Author(s):  
Katrin Hussinger ◽  
Abdul-Basit Issah
Keyword(s):  
Family Firms ◽  
Aspiration Level ◽  
Trade Off ◽  
Financial Wealth ◽  
Performance Pattern ◽  
Behavioral Agency

This study elucidates the mixed gamble confronting family firms when considering a related firm acquisition. The socioemotional and financial wealth trade-off associated with related firm acquisitions as well as their long-term horizon turns family firms more likely to undertake a related acquisition than nonfamily firms, especially when they are performing above their aspiration level. Postmerger performance pattern confirms that family firms are able to create long-term value through these acquisitions, and by doing so, they surpass nonfamily firms. These findings stand in contrast to commonly used behavioral agency predictions but can be reconciled with theory through a mixed gamble lens.

scholarly journals Using Artificial Intelligence to classify Jobseekers: The Accuracy-Equity Trade-off

2020 ◽  
pp. 1-19
Author(s):  
SAM DESIERE ◽  
LUDO STRUYVEN
Keyword(s):  
Artificial Intelligence ◽  
Maximum Level ◽  
Employment Services ◽  
Trade Off ◽  
The Public ◽  
Foreign Origin ◽  
Trade Offs ◽  
Graphical Tool ◽  
The Cost

Abstract Artificial intelligence (AI) is increasingly popular in the public sector to improve the cost-efficiency of service delivery. One example is AI-based profiling models in public employment services (PES), which predict a jobseeker’s probability of finding work and are used to segment jobseekers in groups. Profiling models hold the potential to improve identification of jobseekers at-risk of becoming long-term unemployed, but also induce discrimination. Using a recently developed AI-based profiling model of the Flemish PES, we assess to what extent AI-based profiling ‘discriminates’ against jobseekers of foreign origin compared to traditional rule-based profiling approaches. At a maximum level of accuracy, jobseekers of foreign origin who ultimately find a job are 2.6 times more likely to be misclassified as ‘high-risk’ jobseekers. We argue that it is critical that policymakers and caseworkers understand the inherent trade-offs of profiling models, and consider the limitations when integrating these models in daily operations. We develop a graphical tool to visualize the accuracy-equity trade-off in order to facilitate policy discussions.

Incumbent replacement: evidence for long-term evolutionary progress

Paleobiology ◽  
1991 ◽  
Vol 17 (3) ◽  
pp. 202-213 ◽  
Author(s):  
Michael L. Rosenzweig ◽  
Robert D. McCord
Keyword(s):  
Mass Extinction ◽  
Extinction Rate ◽  
Trade Off ◽  
Evolutionary Progress ◽  
The North ◽  
Pure Chance ◽  
S Curve ◽  
Extinction Events ◽  
Mass Extinction Events

Evolutionary progress is a trend that relaxes trade-off rules. It begins with the evolution of a key adaptation. It continues with the spread of the key adaptation as the clade that contains it replaces some older clade that lacks it. Key adaptations are those that allow for improvement in at least one organismal function at a reduced fitness cost in other functions.Replacement almost certainly involves more than pure chance. It may not often involve competitive extinction. Instead, species from the new clade produce new species to replace already extinct species from the old clade. The key adaptation gives them a higher competitive speciation rate than old-clade sources of replacement. The process, termed incumbent replacement, proceeds at a rate limited by extinction rate. Thus, replacement often seems linked to mass extinction events.The incumbent-replacement hypothesis explains what we know about the replacement of straight-neck turtles (Amphichelydia) by those that can flex their necks and protect their heads in their shells. This replacement occurred four or five times in different biotic provinces. It happened as long ago as the Cretaceous in Eurasia, and as recently as the Pleistocene in mainland Australia. It was accomplished in Gondwanaland by turtles flexing their necks sideways (Pleurodira), and in the north by those flexing their necks into an S-curve (Cryptodira). As is typical of replacements, amphichelydian replacement took millions of years to accomplish wherever it occurred, and much of it in North America took place in a burst associated with and immediately subsequent to a mass extinction.

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