Molecular adaptation of the blood of Antarctic teleosts to environmental conditions

1989 ◽  
Vol 1 (2) ◽  
pp. 119-124 ◽  
Author(s):  
Guido Di Prisco ◽  
Rossana D'Avino
Keyword(s):  
Haemoglobin Concentration ◽  
Oxygen Binding ◽  
Root Effect ◽  
Physiological Relevance ◽  
Antarctic Convergence ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
The Antarctic ◽  
The Relationship ◽  
Antarctic Teleosts

Following the break-up of Gondwana, the drift of Antarctica to its present position and the establishment of the Antarctic Convergence, fish evolution was characterized by adaptation to progressive cooling of the environment. The decrease of erythrocyte number and haemoglobin concentration in the blood of Antarctic teleosts raises several questions concerning the physiology of respiration and the enzymatic role of erythrocytes. Our study of the molecular basis of cold adaptation includes the relationship between molecular structure and biological function of haemoglobins. Species of the suborder Notothenioidei, largely confined within the Convergence, have only one major haemoglobin, which displays the Root effect in oxygen binding; on the other hand, Zoarcidae (a family found at all latitudes) have four or five haemoglobins, only one of which displays the Root effect. In addition, our data indicate that the physiological relevance of erythrocyte-like cells, present in very small number in the blood of haemoglobinless Channichthyidae, may be linked to higher content of enzymes, such as glucose-6-phosphate dehydrogenase, in comparison with erythrocytes of red-blooded fishes.

Oxygen binding of erythrocruorin and coelomic cell haemoglobin from the terebellid polychaete Neoamphitrite figulus related to some environmental factors

1982 ◽  
Vol 62 (2) ◽  
pp. 373-384 ◽  
Author(s):  
Rufus M. G. Wells ◽  
Lynda M. Warren
Keyword(s):  
Haemoglobin Concentration ◽  
Log P ◽  
Oxygen Binding ◽  
Transfer System ◽  
Equilibrium Curve ◽  
High Affinity ◽  
Coelomic Cells ◽  
Hyperbolic Equilibrium ◽  
Oxygen Equilibrium Curve

Measurements of pH, oxygen content, O2-combining capacity, and haemoglobin concentration were made for the vascular blood of the burrowing polychaete Neoamphitrite figulus in order to assess the role of its two respiratory pigments in respiration. The oxygen equilibrium curve of the erythrocruorin (extracellular haemoglobin) in the vessels was sigmoidal, having an n50 value of 1·5 and a low affinity for oxygen as determined by the P50 which was 26 mmHg at pH 7·31 and 18 °C. O2-binding by the erythrocruorin is sensitive to changes in pH (Δ log P50/Δ log pH = –0·24 to –0·29). The coelomic cell haemoglobin has a hyperbolic equilibrium curve (n50 = 1·0) and a high affinity for oxygen (P50 = 4·5 mmHg) independent of pH, suggesting an oxygen transfer system from the erythrocruorin to the coelomic cells.

scholarly journals Insertion Hot Spots of DIRS1 Retrotransposon and Chromosomal Diversifications among the Antarctic Teleosts Nototheniidae

2019 ◽  
Vol 20 (3) ◽  
pp. 701 ◽  
Author(s):  
Juliette Auvinet ◽  
Paula Graça ◽  
Laura Ghigliotti ◽  
Eva Pisano ◽  
Agnès Dettaï ◽  
...  
Keyword(s):  
Hot Spots ◽  
Chromosomal Rearrangements ◽  
Antarctic Fish ◽  
Wide Distribution ◽  
Suitable Model ◽  
Fish Family ◽  
The Antarctic ◽  
Antarctic Teleosts

By their faculty to transpose, transposable elements are known to play a key role in eukaryote genomes, impacting both their structuration and remodeling. Their integration in targeted sites may lead to recombination mechanisms involved in chromosomal rearrangements. The Antarctic fish family Nototheniidae went through several waves of species radiations. It is a suitable model to study transposable element (TE)-mediated mechanisms associated to genome and chromosomal diversifications. After the characterization of Gypsy (GyNoto), Copia (CoNoto), and DIRS1 (YNoto) retrotransposons in the genomes of Nototheniidae (diversity, distribution, conservation), we focused on their chromosome location with an emphasis on the three identified nototheniid radiations (the Trematomus, the plunderfishes, and the icefishes). The strong intrafamily TE conservation and wide distribution across species of the whole family suggest an ancestral acquisition with potential secondary losses in some lineages. GyNoto and CoNoto (including Hydra and GalEa clades) mostly produced interspersed signals along chromosomal arms. On the contrary, insertion hot spots accumulating in localized regions (mainly next to centromeric and pericentromeric regions) highlighted the potential role of YNoto in chromosomal diversifications as facilitator of the fusions which occurred in many nototheniid lineages, but not of the fissions.

scholarly journals Providing expert scientific advice on the Antarctic environment

1994 ◽  
Vol 6 (1) ◽  
pp. 1-1 ◽  
Author(s):  
D.W.H. Walton
Keyword(s):  
Decision Making ◽  
Human Activities ◽  
Scientific Advice ◽  
Politics And Science ◽  
The World ◽  
Antarctic Treaty ◽  
The Antarctic ◽  
The Relationship ◽  
Antarctic Environment

It is hard to divorce most human activities, including science, completely from politics. Politics is about perceived certainty whilst science is about doubt – they make strange bedfellows. Politicians detest probabilities whilst scientists abhor the absolute. Nowhere is the relationship between politics and science more publicly developed than in the Antarctic Treaty System. In the only continent devoted to peace and science it might be supposed that, after more than thirty years, the role of science would be both more robust and more pivotal in decision-making than elsewhere in the world. So it appears at present but will it remain so?

Allosteric Modulation of Haemocyanin Oxygen-Affinity by L-Lactate and Urate in the Lobster Homarus Vulgaris: I. Specific and Additive Effects on Haemocyanin Oxygen-affinity

1992 ◽  
Vol 168 (1) ◽  
pp. 93-110 ◽  
Author(s):  
B. ZEIS ◽  
A. NIES ◽  
C. R. BRIDGES ◽  
M. K. GRIESHABER
Keyword(s):  
Oxygen Affinity ◽  
Physiological Role ◽  
Allosteric Modulation ◽  
Oxygen Binding ◽  
Additive Effects ◽  
Simultaneous Presence ◽  
Specific Effects ◽  
The Relationship

The specific effects of L-lactate and urate on oxygen binding by the haemocyanin of the lobster Homarus vulgaris were investigated. Increasing concentrations of L-lactate were found to increase haemocyanin oxygen-affinity. The relationship between the oxygen affinity (ΔlogP50) and [L-lactate] expressed as (ΔlogP50)(Δlog[L-lactate])−1 was −0.11 at L-lactate concentrations between 0.3 and 11mmoll−1 and pH7.99±0.03. Urate, likewise, had a potentiating effect on haemocyanin oxygen-affinity: (ΔlogP50)(Δlog[L-lactate)−1 was −0.18 at urate concentrations between 0 and 0.93mmoll−1 and pH7.99±0.03. Cooperativity, expressed as n50, was reduced by the presence of both modulators. The influence of the simultaneous presence of both factors on haemocyanin oxygen-affinity was also investigated. The effects of L-lactate and urate on haemocyanin oxygen-affinity were found to be additive. The possible physiological role of these modulators is discussed. Note: To whom reprint requests should be addessed.

Choosing a Markov blanket

2020 ◽  
Vol 43 ◽  
Author(s):  
Thomas Parr
Keyword(s):  
Markov Blanket ◽  
Target Article ◽  
The Relationship

Abstract This commentary focuses upon the relationship between two themes in the target article: the ways in which a Markov blanket may be defined and the role of precision and salience in mediating the interactions between what is internal and external to a system. These each rest upon the different perspectives we might take while “choosing” a Markov blanket.

Staring Down Death

Crisis ◽  
2016 ◽  
Vol 37 (3) ◽  
pp. 212-217 ◽  
Author(s):  
Thomas E. Joiner ◽  
Melanie A. Hom ◽  
Megan L. Rogers ◽  
Carol Chu ◽  
Ian H. Stanley ◽  
...  
Keyword(s):  
Suicide Risk ◽  
Clinical Utility ◽  
Blink Rate ◽  
Specific Task ◽  
Careful Planning ◽  
Eye Blink ◽  
Eye Blinks ◽  
Potential Clinical Utility ◽  
The Relationship

Abstract. Background: Lowered eye blink rate may be a clinically useful indicator of acute, imminent, and severe suicide risk. Diminished eye blink rates are often seen among individuals engaged in heightened concentration on a specific task that requires careful planning and attention. Indeed, overcoming one’s biological instinct for survival through suicide necessitates premeditation and concentration; thus, a diminished eye blink rate may signal imminent suicidality. Aims: This article aims to spur research and clinical inquiry into the role of eye blinks as an indicator of acute suicide risk. Method: Literature relevant to the potential connection between eye blink rate and suicidality was reviewed and synthesized. Results: Anecdotal, cognitive, neurological, and conceptual support for the relationship between decreased blink rate and suicide risk is outlined. Conclusion: Given that eye blinks are a highly observable behavior, the potential clinical utility of using eye blink rate as a marker of suicide risk is immense. Research is warranted to explore the association between eye blink rate and acute suicide risk.

Parenting Behaviors and Anxiety in Young Adults

2015 ◽  
Vol 36 (3) ◽  
pp. 170-176 ◽  
Author(s):  
Erin N. Stevens ◽  
Joseph R. Bardeen ◽  
Kyle W. Murdock
Keyword(s):  
Effortful Control ◽  
Parenting Behaviors ◽  
Protective Role ◽  
Anxiety Symptoms ◽  
Interactive Effects ◽  
Parental Overprotection ◽  
High Control ◽  
Development Of Anxiety ◽  
The Relationship

Parenting behaviors – specifically behaviors characterized by high control, intrusiveness, rejection, and overprotection – and effortful control have each been implicated in the development of anxiety pathology. However, little research has examined the protective role of effortful control in the relation between parenting and anxiety symptoms, specifically among adults. Thus, we sought to explore the unique and interactive effects of parenting and effortful control on anxiety among adults (N = 162). Results suggest that effortful control uniquely contributes to anxiety symptoms above and beyond that of any parenting behavior. Furthermore, effortful control acted as a moderator of the relationship between parental overprotection and anxiety, such that overprotection is associated with anxiety only in individuals with lower levels of effortful control. Implications for potential prevention and intervention efforts which specifically target effortful control are discussed. These findings underscore the importance of considering individual differences in self-regulatory abilities when examining associations between putative early-life risk factors, such as parenting, and anxiety symptoms.

Social Support, Emotional Intelligence, and Posttraumatic Stress Disorder Symptoms

2016 ◽  
Vol 37 (1) ◽  
pp. 31-39 ◽  
Author(s):  
Nicole L. Hofman ◽  
Austin M. Hahn ◽  
Christine K. Tirabassi ◽  
Raluca M. Gaher
Keyword(s):  
Social Support ◽  
Posttraumatic Stress Disorder ◽  
Emotional Intelligence ◽  
Protective Factors ◽  
Posttraumatic Stress ◽  
Stress Disorder ◽  
Traumatic Events ◽  
Ptsd Symptoms ◽  
The Relationship

Abstract. Exposure to traumatic events and the associated risk of developing Posttraumatic stress disorder (PTSD) symptoms is a significant and overlooked concern in the college population. It is important for current research to identify potential protective factors associated with the development and maintenance of PTSD symptoms unique to this population. Emotional intelligence and perceived social support are two identified protective factors that influence the association between exposure to traumatic events and PTSD symptomology. The current study examined the mediating role of social support in the relationship between emotional intelligence and PTSD symptoms. Participants included 443 trauma-exposed university students who completed online questionnaires. The results of this study indicated that social support mediates the relationship between emotional intelligence and reported PTSD symptoms. Thus, emotional intelligence is significantly associated with PTSD symptoms and social support may play an integral role in the relationship between emotional intelligence and PTSD. The current study is the first to investigate the role of social support in the relationship between emotional intelligence and PTSD symptoms. These findings have important treatment and prevention implications with regard to PTSD.

Coping Humor as a Mediator Between Emotional Intelligence and Job Satisfaction

2017 ◽  
Vol 16 (3) ◽  
pp. 155-159 ◽  
Author(s):  
Peizhen Sun ◽  
Jennifer J. Chen ◽  
Hongyan Jiang
Keyword(s):  
Job Satisfaction ◽  
Emotional Intelligence ◽  
Future Research ◽  
Satisfaction Scale ◽  
Primary School Teachers ◽  
Mediating Role ◽  
Regulation Of Emotion ◽  
The Relationship ◽  
Overall Job Satisfaction

Abstract. This study investigated the mediating role of coping humor in the relationship between emotional intelligence (EI) and job satisfaction. Participants were 398 primary school teachers in China, who completed the Wong Law Emotional Intelligence Scale, Coping Humor Scale, and Overall Job Satisfaction Scale. Results showed that coping humor was a significant mediator between EI and job satisfaction. A further examination revealed, however, that coping humor only mediated two sub-dimensions of EI (use of emotion and regulation of emotion) and job satisfaction. Implications for future research and limitations of the study are discussed.

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