scholarly journals Oviductal fluid counterbalances the negative effect of high temperature on sperm in an ectotherm model

Biology Open ◽  
2021 ◽  
pp. bio.058593
Author(s):  
N. Rossi ◽  
G. Lopez Juri ◽  
M. Chiaraviglio ◽  
G. Cardozo
Keyword(s):  
Global Warming ◽  
High Temperature ◽  
Reproductive Tract ◽  
Thermal Environment ◽  
Sperm Quality ◽  
Thermal Requirements ◽  
Negative Effect ◽  
Neutral Conditions ◽  
Oviductal Fluid

Global warming is affecting biodiversity; however, the extent to which animal reproductive processes respond to predicted temperature increments remains largely unexplored. The thermal environment has a pronounced impact on metabolic rates of ectotherms; therefore, an interesting question to assess is whether temperature increase might affect specific reproductive mechanisms like sperm performance in ectotherms. Moreover, in many species, oviductal fluid (OF) is known to regulate and maintain sperm quality; however, the role of oviductal fluid in relation to the effects of high temperature on sperm remains unclear. Our aim was to experimentally test the effect of increased temperature on sperm velocity, swimming path and percentage of motility in neutral conditions at ejaculation (without OF) and in femalés reproductive tract fluid (with OF), in a social ectotherm lizard model, Tropidurus spinulosus, which has specific thermal requirements for reproduction. Our results suggest that a rising temperature associated with global warming (+4°C) affects negatively sperm dynamics and survival. However, OF fluid ameliorated the harmful effects of high temperature. This is an important point, as this study is the first that ever tested the role of OF to preserve sperm from a warmer pre-fertilization environment. These results contribute to our understanding of how thermal environment changes might affect post-copulatory reproductive mechanisms.

scholarly journals First person – Nicola Rossi

Biology Open ◽  
2021 ◽  
Vol 10 (4) ◽  
Keyword(s):  
Global Warming ◽  
High Temperature ◽  
Early Career ◽  
First Person ◽  
Social Mechanisms ◽  
Lizard Species ◽  
Early Career Researchers ◽  
Negative Effect ◽  
Oviductal Fluid ◽  
Selection Of

ABSTRACT First Person is a series of interviews with the first authors of a selection of papers published in Biology Open, helping early-career researchers promote themselves alongside their papers. Nicola Rossi is first author on ‘Oviductal fluid counterbalances the negative effect of high temperature on sperm in an ectotherm model’, published in BiO. Nicola is a PhD student in the lab of Margarita Chiaraviglio and Gabriela Cardozo at Instituto IDEA, Córdoba, Argentina, studying the effects of global warming on seuxal selection and social mechanisms in a lizard species native to South America, Tropidurus spinulosus.

scholarly journals Evolution of the grapevine bud dormancy under different thermal regimes

2019 ◽  
Vol 40 (6Supl3) ◽  
pp. 3419
Author(s):  
Rafael Anzanello
Keyword(s):  
High Temperature ◽  
Thermal Regime ◽  
Heat Waves ◽  
Bud Dormancy ◽  
Southern Brazil ◽  
Thermal Requirements ◽  
Thermal Regimes ◽  
Negative Effect ◽  
Chilling Hours ◽  
Winter Chilling

Fluctuations in winter chilling availability impact bud dormancy and budburst. This study aimed to quantify the thermal requirements during dormancy for ‘Italia’ grape, under different thermal regimes. Cuttings of grapevines ‘Itália’ were collected in Veranópolis-RS, on April/2017, with zero chilling hours (CH). The cuttings were exposed to constant (7.2°C) or alternating (7.2 and 18°C for 12/12h, 12/12h or 18/6h) temperatures, or yet, a constant temperature (7.2°C) or alternating (7.2 and 18°C for 12/12h), combined with one or two days a week at 25°C. Periodically, part of the cuttings was transferred to 25°C for daily budburst evaluation. The induction of the endodormancy (dormancy induced by cold) occurred with 200 CH, independent of the thermal regime, and the overcoming with 300 HF, at 7.2°C. The alternating heat of 18°C in the middle of the cold did not affect the process of overcoming endodormancy. Heat waves during endodormancy resulted in an increased CH to overcome the bud dormancy. The negative effect of high temperature depended on the exposure time. Chilling was partly cancelled during dormancy when the heat wave lasted 36 continuous hours or more. These evidences serve as basis for new model adjustments for budburst prediction, especially for regions with mild and irregular winters, such as those of Southern Brazil.

scholarly journals Population dynamics and biting rhythm of the anthropophilic sandfly Lutzomyia cruciata (Diptera: Psychdidae) in Southeast, Mexico

1996 ◽  
Vol 38 (1) ◽  
pp. 29-33 ◽  
Author(s):  
Eduardo A. Rebollar-Tellez ◽  
Filiberto Reyes-Villanueva ◽  
Ildefonso Fernandez-Salas ◽  
Fernando J. Andrade-Narvaez
Keyword(s):  
Population Dynamics ◽  
High Temperature ◽  
The State ◽  
Endemic Focus ◽  
Host Seeking ◽  
Biting Rate ◽  
Population Peak ◽  
Negative Effect ◽  
Southeast Mexico

Sandflies attracted by human bait were caught in an endemic focus of localized cutaneous leishmaniasis in the state of Campeche, Mexico. Catches were carried out monthly from February 1994 to January 1995 between 18:00 and 22:00 h. Lutzomyia cruciata was the only species caught. The highest population peak of Lu. cruciata was found in March with lesser peaks in February, December 1994, and January 1995. Maximum biting rate of Lu. cruciata was found between 18:00 and 19:00 h. The host-seeking females of Lu. cruciata were directly related to levels of humidity between 88 and 100%. Low and high temperature had a negative effect upon Lu. cruciata activity. The possible role of Lu. cruciata as vector of leishmaniasis in the state of Campeche, Mexico is discussed.

150 Effect of bovine seminal plasma and sperm on endometrial gene expression

2019 ◽  
Vol 31 (1) ◽  
pp. 200
Author(s):  
B. Fernandez-Fuertes ◽  
J. M. Sanchez ◽  
S. Bages ◽  
P. Lonergan
Keyword(s):  
Gene Expression ◽  
Seminal Plasma ◽  
Reproductive Tract ◽  
Epididymal Sperm ◽  
Rna Integrity ◽  
Rna Quality ◽  
Rna Integrity Number ◽  
Maternal Immune System ◽  
Negative Effect

In cattle, most pregnancy losses are sustained before implantation. Many factors are involved in implantation failure, but in mice, pigs and humans there is increased evidence of a role for the maternal immune system and its regulation by seminal plasma (SP). However, there is little evidence for a role of SP in bovine fertility, where dilution or removal of SP before AI is routine. Therefore, the aim of this work was to determine the effect of bull SP or sperm on endometrial gene expression. To this end, 6 heifers were oestrous synchronised and slaughtered 12h after the onset of oestrus. Five endometrial explants from the horn ipsilateral to the preovulatory follicle were obtained from each animal. Explants were incubated with (1) RPMI medium (control); (2) epididymal sperm (106 epididymal sperm mL−1); (3) complete ejaculate (106 ejaculated sperm mL−1+25% SP); (4) ejaculated sperm alone (106 ejaculated sperm mL−1); and (5) SP alone (25% SP). Epididymal sperm were collected and pooled from the cauda epididymis of 3 bulls slaughtered in a commercial abattoir. In addition, complete ejaculates were obtained from 3 other bulls using an artificial vagina. After pooling the samples, a small volume was washed through a density gradient to obtain the ejaculated sperm, and the rest of the ejaculate was filtered to obtain sperm-free SP. The RPMI media was used to dilute sperm and SP to the working concentrations. After 6h of incubation, explants were snap frozen. The RNA quality was assessed with an Agilent 2100 bioanalyzer (Agilent, Santa Clara, CA, USA) before RT-qPCR analysis. Interestingly, SP had a dramatic effect on endometrium RNA integrity, as evidenced by a lower RNA integrity number in explants exposed to a complete ejaculate (2.4±0.14) or SP (2.4±0.06), in comparison with the control, epididymal sperm, or ejaculated sperm treatments (6.7±0.43, 6.9±0.32, 6.7±0.30, respectively; P<0.05). Due to the low RNA quality, those treatments were excluded from further analysis. However, this finding is currently being explored, along with the possibility of this effect being inherent to species that ejaculate intravaginally. We then compared the ability of ejaculated sperm (which have been exposed to SP) and epididymal sperm (which have never had contact with SP) to regulate the endometrial expression of IL1A, IL1B, IL8, IL6, PTGES2, TNFA, and LIF. Although IL6, IL1A and LIF increased in all animals when exposed to either ejaculated or epididymal sperm, there was no effect of treatment. In conclusion, these data did not support the notion that exposure of sperm to SP is important for the immune regulation of the bovine uterus. In addition, the negative effect of SP on the endometrium, together with the fact that bulls are intravaginal ejaculators, suggests that any putative immunoregulatory role of this fluid in the cattle uterus is indirect. Further analysis of the effect of SP on the vagina and cervix will help elucidate whether this response is present in this species and whether it can propagate to more distal regions of the reproductive tract. This work was supported by Science Foundation Ireland (13/IA/1983, 16/IA/4474).

Lethal Temperatures of the Developmental Stages of the Sea Lamprey, Petromyzon marinus L.

1963 ◽  
Vol 20 (2) ◽  
pp. 483-490 ◽  
Author(s):  
R. W. McCauley
Keyword(s):  
High Temperature ◽  
Developmental Stages ◽  
Petromyzon Marinus ◽  
Temperature Characteristic ◽  
Sea Lamprey ◽  
Natural Conditions ◽  
Thermal Requirements ◽  
Lethal Temperatures

Of all stages of the sea lamprey, the eggs have the most exacting thermal requirements. The range of constant temperatures necessary for successful hatching is narrow, being 15–25 °C. This range may be extended to 12–26 °C and possibly beyond, if the eggs have developed to the head stage before they encounter temperature extremes.The ability to withstand high temperature characteristic of the post-embryonic stages of the species appears shortly before or after hatching.The role of temperature in the development of eggs under natural conditions is discussed.

Social Motives Predict Loneliness During a Developmental Transition

2017 ◽  
Vol 76 (4) ◽  
pp. 145-153 ◽  
Author(s):  
Jana Nikitin ◽  
Alexandra M. Freund
Keyword(s):  
Social Relationships ◽  
Well Being ◽  
Social Avoidance ◽  
Social Approach ◽  
Social Motives ◽  
Developmental Transitions ◽  
Avoidance Motivation ◽  
Negative Effect ◽  
Low Levels

Abstract. Establishing new social relationships is important for mastering developmental transitions in young adulthood. In a 2-year longitudinal study with four measurement occasions (T1: n = 245, T2: n = 96, T3: n = 103, T4: n = 85), we investigated the role of social motives in college students’ mastery of the transition of moving out of the parental home, using loneliness as an indicator of poor adjustment to the transition. Students with strong social approach motivation reported stable and low levels of loneliness. In contrast, students with strong social avoidance motivation reported high levels of loneliness. However, this effect dissipated relatively quickly as most of the young adults adapted to the transition over a period of several weeks. The present study also provides evidence for an interaction between social approach and social avoidance motives: Social approach motives buffered the negative effect on social well-being of social avoidance motives. These results illustrate the importance of social approach and social avoidance motives and their interplay during developmental transitions.

THE NOTHING THAT REALLY IS!

2016 ◽  
Vol 12 (1) ◽  
pp. 4172-4177
Author(s):  
Abdul Malek
Keyword(s):  
Quantum Dynamics ◽  
Theoretical Physics ◽  
Historical Evolution ◽  
Proper Understanding ◽  
Physical Universe ◽  
Wave Particle Duality ◽  
Negative Effect ◽  
Materialist Interpretation

The denial of the existence of contradiction is at the root of all idealism in epistemology and the cause for alienations.  This alienation has become a hindrance for the understanding of the nature and the historical evolution mathematics itself and its role as an instrument in the enquiry of the physical universe (1). A dialectical materialist approach incorporating  the role of the contradiction of the unity of the opposites, chance and necessity etc., can provide a proper understanding of the historical evolution of mathematics and  may ameliorate  the negative effect of the alienation in modern theoretical physics and cosmology. The dialectical view also offers a more plausible materialist interpretation of the bewildering wave-particle duality in quantum dynamics (2).

The Potential of Photoelectrochemical Carbon Sinks

2018 ◽  
Author(s):  
Matthias May ◽  
Kira Rehfeld
Keyword(s):  
Global Warming ◽  
High Temperature ◽  
Greenhouse Gas ◽  
Large Scale ◽  
High Efficiency ◽  
Carbon Sink ◽  
Solar Fuels ◽  
Negative Emissions ◽  
Viable Approach ◽  
Low Sensitivity

Greenhouse gas emissions must be cut to limit global warming to 1.5-2C above preindustrial levels. Yet the rate of decarbonisation is currently too low to achieve this. Policy-relevant scenarios therefore rely on the permanent removal of CO<sub>2</sub> from the atmosphere. However, none of the envisaged technologies has demonstrated scalability to the decarbonization targets for the year 2050. In this analysis, we show that artificial photosynthesis for CO<sub>2</sub> reduction may deliver an efficient large-scale carbon sink. This technology is mainly developed towards solar fuels and its potential for negative emissions has been largely overlooked. With high efficiency and low sensitivity to high temperature and illumination conditions, it could, if developed towards a mature technology, present a viable approach to fill the gap in the negative emissions budget.<br>

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