scholarly journals Effect of different ambient temperatures on reproductive outcome and wellbeing of lactating females in two mouse strains

2021 ◽  
Author(s):  
Thomas Kolbe ◽  
Caroline Lassnig ◽  
Andrea Poelzl ◽  
Rupert Palme ◽  
Kerstin Elisabeth Auer ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Reproductive Performance ◽  
Mouse Strains ◽  
Stress Hormone ◽  
Ambient Temperatures ◽  
Reduced Body ◽  
Lactating Females ◽  
Corticosterone Metabolites ◽  
And Control ◽  
Fecal Corticosterone Metabolites

Ambient temperature is an important non-biotic environmental factor influencing immunological and oncological parameters in laboratory mice. It is under discussion which temperature is more appropriate and whether the commonly used room temperature in rodent facilities of about 21°C represents a chronic cold stress or the 30°C of the thermoneutral zone constitutes heat stress for the animals. In this study we selected the physiological challenging period of lactation to investigate the influence of a cage temperature of 20°C, 25°C, and 30°C, respectively, on reproductive performance and stress hormone levels in two frequently used mouse strains. We found that more pups were weaned from B6D2F1 hybrids compared to C57BL/6N mothers and that the number of weaned pups was strongly reduced if mothers of both strains were kept at 30°C. Furthermore, at 30°C mothers and pups showed reduced body weight at weaning and offspring had longer tails. Despite pronounced temperature effects on reproductive parameters, we did not find any impact on adrenocortical activity in breeding and control mice. Independent of the ambient temperature however, we found that females raising pups showed elevated levels of fecal corticosterone metabolites (FCMs) compared to controls. Increased levels of stress hormone metabolites were measured specially around birth and during the third week of lactation. Our results provide no evidence for reduced or improved wellbeing of lactating mice at different ambient temperatures, but we found that a 30°C cage temperature impairs reproductive performance.

Nitrogen and sulfur metabolism and plasma thyroid hormone concentrations in fleeceweight-selected and control Romney sheep at two ambient temperatures

1994 ◽  
Vol 45 (2) ◽  
pp. 339 ◽  
Author(s):  
YX Sun ◽  
J Lee ◽  
PM Harris ◽  
BR Sinclair ◽  
ID Shelton ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Nitrogen Balance ◽  
Whole Blood ◽  
Dry Matter ◽  
Sulfur Metabolism ◽  
Selection Line ◽  
Irreversible Loss ◽  
Ambient Temperatures ◽  
And Control ◽  
Loss Rates

This study was conducted to determine the effect of ambient temperature on nitrogen and sulfur metabolism in 7-month-old rams from the Massey University fleeceweight-selected (FW) and control (C) lines of Romney sheep. Eight rams from each line were exposed to either 6�C or 25�C ambient temperature under a constant photoperiod. Detailed studies of sulfur metabolism were made on four of the rams from each line at each ambient temperature. Intake and faecal output of dry matter and nitrogen were lower at 25�C than at 6�C, but there was no effect of ambient temperature on digestibility of either dry matter or nitrogen. Nitrogen balance was lower at 25�C than at 6�C, but none of the parameters relating to nitrogen balance was influenced by selection line. There were also no effects of ambient temperature or selection line on clearance rates of urea or creatinine. Blood samples were collected from the animals at 2 h intervals over a 24 h period to determine plasma concentrations of urea, creatinine, thyroxine and triiodothyronine. Although the between-line differences in concentrations of these hormones and metabolites varied throughout the 24 h period, and with ambient temperature, there were no consistent interactions between the effects of selection line and ambient temperature. There were no consistent effects of selection line, or interactions of selection line with ambient temperature, on sulfur and sulfate balances, concentrations of leucine, cyst(e)ine and glutathione in whole blood or on irreversible loss rates of leucine and cyst(e)ine. However, when considered across lines and ambient temperatures, both the whole blood concentrations (P < 0.10) and the irreversible loss rates (P < 0.05) of leucine and cyst(e)ine were positively related to midside wool growth. The only significant (P < 0.05) interaction between selection line and ambient temperature was observed in the wool sulfur concentration which was lower in the FW rams than in the C rams at 6�C, but not at 25�C. It is concluded that none of the metabolic measurements made in this study explains previous inconsistencies observed in metabolic differences between sheep from lines divergently selected on the basis of fleeceweight. Wool sulfur content was again shown to be a potentially useful predictor of genetic merit for fleeceweight, but no clear metabolic basis for differences between the lines could be demonstrated even with detailed measurements of sulfur metabolism.

scholarly journals No island-effect on stress for a rodent from a near-shore archipelago

2019 ◽  
Author(s):  
Nathan D Stewart ◽  
Gabriela F Mastromonaco ◽  
Gary Burness
Keyword(s):  
National Park ◽  
Stress Physiology ◽  
Stress Hormone ◽  
Population Densities ◽  
Island Effect ◽  
Near Shore ◽  
Thousand Islands ◽  
Island Syndrome ◽  
Corticosterone Metabolites ◽  
Fecal Corticosterone Metabolites

Island rodents are often larger and live at higher population densities than their mainland counterparts, characteristics that have been referred to as “island syndrome”. Island syndrome has been well studied, but few studies have tested for island-mainland differences in stress physiology. We evaluated island syndrome within the context of stress physiology of white-footed mice (Peromyscus leucopus) captured from islands (n = 11) and mainland sites (n = 5) in Thousand Islands National Park, Ontario, Canada. Stress physiology was evaluated by quantifying corticosterone, the primary glucocorticoid (stress hormone) of rodents, from hair and its related metabolites from fecal samples. White-footed mice captured in this near-shore archipelago did not display characteristics of island syndrome, nor differences in levels of hair corticosterone or fecal corticosterone metabolites compared with mainland mice. We suggest that island white-footed mice experience similar degrees of stress in the Thousand Islands compared with the mainland. Although we did not find evidence of island syndrome or accompanying changes to stress physiology, we identified relationships between internal (sex, body mass) and external (season) factors and our hormonal indices of stress in white-footed mice.

scholarly journals No island-effect on stress for a rodent from a near-shore archipelago

2019 ◽  
Author(s):  
Nathan D Stewart ◽  
Gabriela F Mastromonaco ◽  
Gary Burness
Keyword(s):  
National Park ◽  
Stress Physiology ◽  
Stress Hormone ◽  
Population Densities ◽  
Island Effect ◽  
Near Shore ◽  
Thousand Islands ◽  
Island Syndrome ◽  
Corticosterone Metabolites ◽  
Fecal Corticosterone Metabolites

Island rodents are often larger and live at higher population densities than their mainland counterparts, characteristics that have been referred to as “island syndrome”. Island syndrome has been well studied, but few studies have tested for island-mainland differences in stress physiology. We evaluated island syndrome within the context of stress physiology of white-footed mice (Peromyscus leucopus) captured from islands (n = 11) and mainland sites (n = 5) in Thousand Islands National Park, Ontario, Canada. Stress physiology was evaluated by quantifying corticosterone, the primary glucocorticoid (stress hormone) of rodents, from hair and its related metabolites from fecal samples. White-footed mice captured in this near-shore archipelago did not display characteristics of island syndrome, nor differences in levels of hair corticosterone or fecal corticosterone metabolites compared with mainland mice. We suggest that island white-footed mice experience similar degrees of stress in the Thousand Islands compared with the mainland. Although we did not find evidence of island syndrome or accompanying changes to stress physiology, we identified relationships between internal (sex, body mass) and external (season) factors and our hormonal indices of stress in white-footed mice.

scholarly journals Non-Invasive Monitoring of Adrenocortical Activity in Three Sympatric Desert Gerbil Species

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 75
Author(s):  
Álvaro Navarro-Castilla ◽  
Mario Garrido ◽  
Hadas Hawlena ◽  
Isabel Barja
Keyword(s):  
Small Sample ◽  
Post Injection ◽  
Control Groups ◽  
Treatment Groups ◽  
Adrenocortical Activity ◽  
Non Invasive ◽  
Endocrine Status ◽  
Corticosterone Metabolites ◽  
Small Sample Sizes ◽  
Fecal Corticosterone Metabolites

The study of the endocrine status can be useful to understand wildlife responses to the changing environment. Here, we validated an enzyme immunoassay (EIA) to non-invasively monitor adrenocortical activity by measuring fecal corticosterone metabolites (FCM) in three sympatric gerbil species (Gerbillus andersoni, G. gerbillus and G. pyramidum) from the Northwestern Negev Desert’s sands (Israel). Animals included into treatment groups were injected with adrenocorticotropic hormone (ACTH) to stimulate adrenocortical activity, while control groups received a saline solution. Feces were collected at different intervals and FCM were quantified by an EIA. Basal FCM levels were similar in the three species. The ACTH effect was evidenced, but the time of FCM peak concentrations appearance differed between the species (6–24 h post-injection). Furthermore, FCM peak values were observed sooner in G. andersoni females than in males (6 h and 18 h post-injection, respectively). G. andersoni and G. gerbillus males in control groups also increased FCM levels (18 h and 48 h post-injection, respectively). Despite the small sample sizes, our results confirmed the EIA suitability for analyzing FCM in these species as a reliable indicator of the adrenocortical activity. This study also revealed that close species, and individuals within a species, can respond differently to the same stressor.

scholarly journals Influence of Ambient Temperature on Radiative and Convective Heat Dissipation Ratio in Polymer Heat Sinks

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2286
Author(s):  
Jan Kominek ◽  
Martin Zachar ◽  
Michal Guzej ◽  
Erik Bartuli ◽  
Petr Kotrbacek
Keyword(s):  
Heat Transfer ◽  
Ambient Temperature ◽  
Convective Heat ◽  
Heat Dissipation ◽  
High Surface ◽  
Heat Sinks ◽  
Fourth Power ◽  
Molding Process ◽  
Ambient Temperatures ◽  
University Of Technology

Miniaturization of electronic devices leads to new heat dissipation challenges and traditional cooling methods need to be replaced by new better ones. Polymer heat sinks may, thanks to their unique properties, replace standardly used heat sink materials in certain applications, especially in applications with high ambient temperature. Polymers natively dispose of high surface emissivity in comparison with glossy metals. This high emissivity allows a larger amount of heat to be dissipated to the ambient with the fourth power of its absolute surface temperature. This paper shows the change in radiative and convective heat transfer from polymer heat sinks used in different ambient temperatures. Furthermore, the observed polymer heat sinks have differently oriented graphite filler caused by their molding process differences, therefore their thermal conductivity anisotropies and overall cooling efficiencies also differ. Furthermore, it is also shown that a high radiative heat transfer leads to minimizing these cooling efficiency differences between these polymer heat sinks of the same geometry. The measurements were conducted at HEATLAB, Brno University of Technology.

scholarly journals Effects of Intrauterine Infusion of a Chitosan Solution on Recovery and Subsequent Reproductive Performance of Early Postpartum Dairy Cows with Endometritis: A Pilot Field Trial

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 197
Author(s):  
Hiroaki Okawa ◽  
Missaka M.P. Wijayagunawardane ◽  
Peter L.A.M. Vos ◽  
Osamu Yamato ◽  
Masayasu Taniguchi ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Reproductive Performance ◽  
Polymorphonuclear Leukocytes ◽  
Prostaglandin F2α ◽  
Chitosan Solution ◽  
Control Group ◽  
Control Groups ◽  
Early Postpartum Period ◽  
Early Postpartum ◽  
And Control

This study investigated the efficacy of intrauterine infusion of a chitosan solution (CHT) on uterine recovery in early postpartum dairy cows with or without endometritis, and their subsequent reproductive performance. In Experiment 1, cows with endometritis at 3 weeks postpartum were administered CHT (n = 5) and prostaglandin F2α (PGF2α) (n = 4). Untreated cows (n = 7) served as the control group. In Experiment 2, 18 cows with a normally recovered uterus at the fresh cow check (mean, 35 days postpartum) were assigned to the CHT (n = 10) and control (n = 8) groups, and intrauterine infusion was conducted in the CHT group. Overall, in Experiment 1, the percentage of polymorphonuclear leukocytes significantly declined in the CHT group (32.3 ± 10.2 to 5.5 ± 2.4, p < 0.05) from week 3 to week 5, but no decline occurred in the PGF2α and control groups. In Experiment 2, the CHT and control groups showed no significant differences in reproductive parameters, suggesting the absence of adverse effects of CHT on fertility. These results suggest that intrauterine infusion of CHT in the early postpartum period effectively accelerates uterine recovery from endometritis and might be a suitable replacement for PGF2α administration.

scholarly journals Insufficient Stability of Clavulanic Acid in Widely Used Child-Appropriate Formulations

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 225
Author(s):  
Ines Mack ◽  
Mike Sharland ◽  
Janneke M. Brussee ◽  
Sophia Rehm ◽  
Katharina Rentsch ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Clavulanic Acid ◽  
Storage Conditions ◽  
Essential Medicines ◽  
Active Components ◽  
Middle Income ◽  
Ambient Temperatures ◽  
Essential Medicines List ◽  
Dispersible Tablets ◽  
The Stability

Amoxicillin-clavulanic acid (AMC) belongs to the WHO Essential Medicines List for children, but for optimal antimicrobial effectiveness, reconstituted dry powder suspensions need to be stored in a refrigerated environment. Many patients in low- and middle-income countries who are sold AMC suspensions would be expected not to keep to the specified storage conditions. We aimed to assess the stability of both ingredients in liquid formulations and dispersible tablets, combined with nationally representative data on access to appropriate storage. Degradation of amoxicillin (AMX) and clavulanic-acid (CLA) was measured in suspensions and dispersible tablets commercially available in Switzerland at different ambient temperatures (8 °C vs. 28 °C over 7 days, and 23 °C vs. 28 °C over 24 h, respectively). Data on access to refrigeration and electricity were assessed from the USAID-funded Demographic and Health Survey program. In suspensions, CLA degraded to a maximum of 12.9% (95% CI −55.7%, +29.9%) at 8°C and 72.3% (95% CI −82.8%, −61.8%) at a 28 °C ambient temperature during an observation period of 7 days. Dispersible tablets were observed during 24 h and CLA degraded to 15.4% (95% CI −51.9%, +21.2%) at 23 °C and 21.7% (−28.2%, −15.1%) at a 28 °C ambient temperature. There is relevant degradation of CLA in suspensions during a 7-day course. To overcome the stability challenges for all active components, durable child-appropriate formulations are needed. Until then, prescribers of AMC suspensions or pharmacists who sell the drug need to create awareness for the importance of proper storage conditions regarding effectiveness of both antibiotics and this recommendation should be reflected in the WHO Essential Medicines List for children.

Inbreeding effects among inbred and outbred laboratory colonies of Peromyscus maniculatus

1992 ◽  
Vol 70 (4) ◽  
pp. 820-824 ◽  
Author(s):  
David O. Ribble ◽  
John S. Millar
Keyword(s):  
Performance Measures ◽  
Reproductive Performance ◽  
First Generation ◽  
Peromyscus Maniculatus ◽  
Survival Rates ◽  
Natural Populations ◽  
Outbreeding Depression ◽  
Sibling Pairs ◽  
Laboratory Colonies ◽  
And Control

We examined the effects of sibling matings upon reproductive performance among inbred and outbred laboratory colonies of Peromyscus maniculatus. The inbred colony was founded by 12 females collected from one locality in Alberta and bred for 20 generations, with 35–45 pairs each generation. The outbred colony consisted of first-generation mice born of wild-caught females from diverse areas in Alberta. Consistent with theoretical expectations, there were no differences in reproductive performance between sibling and control (outbred) pairs within the inbred colony of mice. In contrast, sibling pairs had significantly fewer young per litter than control pairs within the outbred colony. Reproductive performance measures (proportion breeding, days from pairing to first litter, number of litters, and total number of offspring produced) were also significantly lower among sibling pairs from the outbred colony than among sibling pairs from the inbred colony. Lastly, we predicted that reproductive performance of the control pairs from the outbred colony would be less than that of control pairs from the inbred colony, due to outbreeding depression. Contrary to our predictions, average litter survival rates were greatest among the outbred colony control pairs. We suggest that the benefits of inbreeding or outbreeding extend broadly across the inbreeding–outbreeding continuum in natural populations of northern Peromyscus.

Ambient temperature effects on physiological traits of white-tailed deer

1975 ◽  
Vol 53 (6) ◽  
pp. 679-685 ◽  
Author(s):  
J. B. Holter ◽  
W. E. Urban Jr. ◽  
H. H. Hayes ◽  
H. Silver ◽  
H. R. Skutt
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Energy Expenditure ◽  
Ambient Temperature ◽  
Temperature Effects ◽  
Temperature Changes ◽  
Wind Chill ◽  
Ambient Temperatures ◽  
Energy Equilibrium ◽  
Body Energy

Six adult white-tailed deer (Odocoileus virginianus borealis) were exposed to 165 periods of 12 consecutive hours of controlled constant ambient temperature in an indirect respiration calorimeter. Temperatures among periods varied from 38 to 0 (summer) or to −20C (fall, winter, spring). Traits measured were energy expenditure (metabolic rate), proportion of time spent standing, heart rate, and body temperature, the latter two using telemetry. The deer used body posture extensively as a means of maintaining body energy equilibrium. Energy expenditure was increased at low ambient temperature to combat cold and to maintain relatively constant body temperature. Changes in heart rate paralleled changes in energy expenditure. In a limited number of comparisons, slight wind chill was combatted through behavioral means with no effect on energy expenditure. The reaction of deer to varying ambient temperatures was not the same in all seasons of the year.

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