Body Temperatures Research Articles

Live attenuated goatpox vaccination in pregnant Murcia-Granada goats: dosage implications and outcomes

BackgroundInfectious diseases, particularly the Goatpox virus (GTPV) from the Poxviridae family, significantly impact livestock health and agricultural economies, especially in developing regions. Recent GTPV outbreaks in previously eradicated areas underscore the need for effective control measures, with vaccination being the most reliable strategy. This study investigates the effects of administering standard and double doses of live attenuated goatpox vaccine in pregnant Murcia-Granada goats, a non-native breed in Iran, to determine optimal vaccination protocols.ResultsIn 2018, 400 healthy and pregnant Murcia Granada goats imported from Spain were divided into groups of 200 and vaccinated with either a standard dose (0.5 ml) or a double dose (single 0.9 ml injection) of live attenuated goatpox vaccine. Post-vaccination, the goats were monitored daily for clinical signs of infection, with samples collected for PCR analysis to detect the presence of GTPV strains. In group A, which received the standard vaccine dose, no abortions or vaccine-related side effects were observed, and body temperatures remained normal. In group B, administered a double dose, 37% of the goats experienced abortions, displaying signs of GTPV infection, such as skin lesions (pox lesions) and increased body temperatures. Molecular analysis confirmed the vaccine strain of GTPV as the infection source, ruling out external contamination. Statistical analysis showed no significant differences in abortion rates concerning gestational age or t he age of the pregnant goats.ConclusionThe study highlights the importance of adhering to standard vaccine dosages in pregnant Murcia Granada goats to prevent adverse outcomes like abortions. This study emphasizes the necessity to review and revise vaccination protocols tailored to specific breeds and varying maintenance conditions, including pregnancy and outbreak scenarios. These findings stress the necessity for cautious and tailored vaccination strategies to ensure the safety and efficacy of vaccines in different goat breeds.

Development of a laser-based process to produce a hermetically sealed contacting interface for the encapsulation of temperature-sensitive electronic components

In the construction of hermetically sealed encapsulations, feedthroughs are commonly required as contacting interfaces. The so-called GTMS (glass-to-metal seal) feedthroughs are often used in the field of sensor technology, acting as an interface between sensor unit and evaluation electronics. GTMS feedthroughs, consisting of a metal mount, a glass body, and contacts, transfer electricity, electrical, or optical signals through a glass-based barrier while protecting the inside of a sensor from the ingress of dust, moisture, or gases. They are mainly used in humidity, temperature, pressure, flow, and vacuum sensors and are actually produced in a furnace process in which the entire components are heated to the melting temperature (>400 °C) of the glass body. Sufficient heat must be applied to reduce the viscosity of the glass body to ensure a reliable wetting of mount and contacts. If temperature-sensitive components are involved, a furnace process is not suitable as the high temperatures damage these components. In this case, a technology with localized energy input is required. A laser-based process enables the reduction of the thermal load. Therefore, investigations on the manufacture of compressed GTMS feedthroughs for multilayer low temperature cofired ceramic with a diode laser have been performed, which are described in the following paper. Depending on the irradiation energy, the melting and wetting behavior of the glass body is determined. Results on the influence of the process parameters on the heat input and the thermal load of the components are discussed and quality-relevant properties such as helium tightness and burst pressure resistance of the laser-produced feedthroughs are evaluated.

Modulation of cutaneous vasodilation by reactive oxygen species during local and whole body heating in young and older adults.

We evaluated reactive oxygen species (ROS) modulation of cutaneous vasodilation during local and whole body passive heating in young and older adults. Cutaneous vascular conductance normalized to maximum vasodilation (%CVCmax) was assessed in young and older adults (10/group) using laser-Doppler flowmetry at four dorsal forearm sites treated with 1) Ringer solution (control), 2) 100 µM apocynin (NADPH oxidase inhibitor), 3) 10 µM allopurinol (xanthine oxidase inhibitor), or 4) 10 µM tempol (superoxide dismutase mimetic), via intradermal microdialysis during local (protocol 1) and whole body heating (protocol 2). In protocol 1, forearm skin sites were set at 33°C during baseline and then progressively increased to 39°C and 42°C (30 min each). In protocol 2, participants were immersed in warm water (35°C, midsternum) with the experimental forearm above water level, and local skin sites were maintained at 34°C. Bath temperature was increased (∼40°C) to clamp core temperature at 38.5°C for 60 min. In protocol 1, there were significant treatment site by age interactions for the 39°C (P = 0.015) and 42°C (P = 0.004) plateaus; however no significant effects were observed after post hoc adjustment. In protocol 2, there was a significant treatment site by age interaction (P < 0.001), where %CVCmax in older adults was 11.0% [7.4, 14.6] higher for apocynin (P < 0.001), 8.9% [5.3, 12.5] higher for allopurinol (P < 0.001), and 4.8% [1.3, 8.4] higher for tempol (P = 0.016) sites relative to the control site. ROS derived from NADPH oxidase and xanthine oxidase attenuate cutaneous vasodilation in older adults during passive whole body heating, but not during local skin heating, with negligible effects on their young counterparts for either heating modality.NEW & NOTEWORTHY We found that local infusion of apocynin or allopurinol improved cutaneous vasodilator responses to passive whole body heating (but not local skin heating) in healthy older adults. These findings indicate that impaired microvascular responses to whole body heating with primary aging are linked to augmented production of reactive oxygen species (ROS) from NADPH oxidase and xanthine oxidase. This study sheds new light on the specific ROS pathways that modulate age-related changes in cutaneous microvascular responses to heating.

Use of ultrasonography in the diagnosis of pneumonia in intensive care patients

Aims: A significant portion of respiratory system infections seen in intensive care units is ventilator-associated pneumonia, which has a high mortality rate and diagnosis may be delayed. Bedside lung ultrasonography offers the advantages of standard diagnostic methods as chest radiography or thorax tomography. We aim to evaluate the bedside lung ultrasonography correlation with the chest radiography or thorax tomography Methods: It was conducted prospectively on 60 patients between the ages of 18-85 who were admitted to intensive care with respiratory failure within an 8-month period. Anterioposterior chest radiographs were taken on the first day of mechanical ventilation for the patients included in the study. Ultrasonographic (USG) examination was performed separately for both hemithoraxes and recorded digitally. Simultaneously with the ultrasonographic examination, PEEP, FiO2, blood gas examination results and the highest body temperatures in the last 24 hours were recorded. The quality and quantity of tracheal secretions were evaluated, and sampling was performed for complete blood examination and tracheal aspirate culture-antibiogram. Lung injury score (LIS) and pulmonary infection score (CPIS) were calculated from the data obtained. In this process, independent of the research, the same day examination results of patients who required thorax tomography (CT) for diagnosis and treatment planning were evaluated together with USG and chest radiography. Tomographic examinations were evaluated by a radiologist. Results: In the examination of 120 hemithoraxes of 60 patients we included in the study, we were able to detect 74.17% of the pathological images obtained with chest radiography and ultrasonographic examination with bedside ultrasonography and 70.84% with chest radiography. Of the 20 patients who underwent tomographic evaluation, pathology was observed in 40 hemithoraxes in 92.5% by tomography, in 85% by ultrasonography, and in 75% by chest radiography. While isolated consolidation was detected equally on USG and CT imaging, there was a high false-positive rate of 48% on chest radiography. 58.8% of the patients with consolidation detected by CT, we observed that there was growth in the tracheal aspirate of 56.2% of the patients whose ultrasonographic examination revealed consolidation. Conclusion: Bedside lung ultrasonography is a fast, non-invasive, repeatable and reliable diagnostic method in patients followed in intensive care, and is compatible with traditionally used laboratory and clinical parameters. This reveals that USG, which is known to have other advantages such as cost, applicability, and not using radiopaque, will become an indispensable examination for ICU.

Assessment of Debris Apical Extrusion, Unprepared Surface Areas, and Dentinal Crack Formation after Root Canal Preparation Using ProTaper Next, ProTaper Ultimate, and R-Motion File Systems

This study evaluated and compared the amount of apically extruded debris, unprepared wall surface areas, and dentinal crack formation resulting from root canal preparation using ProTaper Next (PTN), ProTaper Ultimate (PTU), and R-Motion (RM) file systems. Forty-five palatal roots of maxillary first molars were shortened to a uniform length of 12mm. The samples were divided randomly into three groups (n = 15/group) to be prepared using either PTN, PTU, and RM file systems. The investigator adopted modified Myers and Montgomery's approach to replicate the temperature of the human body. Debris was collected in vials and weighed before and after instrumentation with a sensitive balance. Every specimen was irrigated using distilled water during preparation, utilizing a side-vented needle. Weight before instrumentation was subtracted from weight after instrumentation to identify the weight of the collected debris. CBCT scans were taken before and after canal preparation using a Planmeca ProMax CBCT machine. The unprepared canal surface area was calculated by superimposing preoperative and postoperative CBCT images using the Mimics Medical program. After preparation, a low-speed diamond disc horizontally sectioned the roots at three, six, and nine millimeters from the apex. The specimens were examined under a digital microscope to detect crack formation. Statistical analysis was carried out using one-way (ANOVA) and Tukey (HSD) tests, with a significance level of p<0.05. There was no statistically significant difference in the quantity of debris extruded apically and dentinal crack numbers between the three shaping files (p > 0.05). Only the apical third of root canals prepared by PTU displayed a significantly lower unprepared surface area compared to PTN and RM. Instrumentation with PTN, PTU, and RM yielded similar amounts of apically extruded debris and dentinal cracks. The PTU files demonstrated higher effectiveness in preparing the apical third by reducing the unprepared surface area in the prepared root canal.

Prime Basking Sites and Communal Basking in the Lizard, Lacerta bilineata; High Risk for Juveniles?

Sunlight and the heat it provides are important ecological resources for reptiles especially for those species living in temperate zones that bask extensively to maximize heat uptake. Sun basking has both benefits and costs for reptiles, giving heat that provides the energy to drive physiology but basking in open patches increases risk of predation due to higher visibility. Prime basking sites are believed to increase benefits for reptiles that include, in addition to open sunlit areas, facilitate detection of predators and prey and escape to nearby refuges. However, if such sites are limited, both inter and intra-specific interference may occur and this kind of competition may impact on a reptile’s ability to access prime basking sites, and as a consequence, its capacity to thermoregulate to optimum body temperatures. This may be especially important for juveniles, for whom rapid growth is a key factor in survivorship. We studied communal basking and interaction events at prime basking sites in the European green lizard, Lacerta bilineata, in a hedgerow in western France. We compared basking behaviour of adults and juveniles with sympatric adult wall lizards Podarcis muralis using non-invasive photographic-mark-recapture. Adult L. bilineata were more evenly distributed across basking sights compared to juveniles but significant differences were only detected between males and juveniles. Juvenile L. bilineata abandoned basking sites at the approach of both adult males and females and were aggressively removed by adult male L. bilineata. We found inter-specific communal basking between both adult and juvenile L. bilineata with adult wall lizards P. muralis. Communal basking was observed between male and female L. bilineata but not between adult males or between adult female L. bilineata. Communal basking was in proportionally greater frequency in juveniles compared to adult L. bilineata.

The Art of Chilling Out: How Neurons Regulate Torpor.

Endothermic animals expend significant energy to maintain high body temperatures, which offers adaptability to varying environmental conditions. However, this high metabolic rate requires increased food intake. In conditions of low environmental temperature and scarce food resources, some endothermic animals enter a hypometabolic state known as torpor to conserve energy. Torpor involves a marked reduction in body temperature, heart rate, respiratory rate, and locomotor activity, enabling energy conservation. Despite their biological significance and potential medical applications, the neuronal mechanisms regulating torpor still need to be fully understood. Recent studies have focused on fasting-induced daily torpor in mice due to their suitability for advanced neuroscientific techniques. In this review, we highlight recent advances that extend our understanding of neuronal mechanisms regulating torpor. We also discuss unresolved issues in this research field and future directions.

Effects of COVID-19 virus-like particles on the behavioral and cognitive performance of human apolipoprotein E targeted replacement mice

IntroductionThe effects of viral infections might be apolipoprotein E (apoE) isoform-dependent. In humans, there are three major apoE isoforms, E2, E3, and E4. E4 is associated with the enhanced entry of several viruses into the brain and their disease progression. A concern of infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the development of post-acute COVID-19 syndrome, also known as long COVID. Genetic risk factors for developing long COVID were reported.MethodsIn this study, we used virus-like particles (VLPs) that include expression of the SARS-CoV-2 nucleocapsid (N), membrane (M), and envelope (E) structural proteins together with S. In the current study, we used human E2, E3, and E4 targeted replacement mice to assess whether these VLPs affect body weight, behavioral and cognitive performance, and circadian body temperatures. Using VLPs allow working outside an ABSL-3 facility.ResultsThe effects of VLPs on some behavioral measures were apoE isoform-dependent, with the E2 mice being more affected than E3 or E4 mice. The overall decreased activity in the open field containing objects in week 2 indicate that VLPs can also reduce activity levels in an apoE isoform-independent fashion.DiscussionThe results of the current study indicate that even in the absence of viral replication, detrimental effects of VLPs on behavioral measures and circadian body temperatures are seen.

Effects of bidirectional thermoregulation materials on sport efficacy, physiology, and psychology in hot and cold environments

Bidirectional thermoregulation materials can absorb or release heat in different external environments and automatically adjust the temperature of human body, while are less used in daily and sports functional clothing. In order to further study their impact on lower limb movement, thermal performance of thermoregulation and ordinary fabrics were compared, and human wearing experiments were conducted in cold and hot environments (15 °C and 30 °C). The results showed that thermoregulation sports pants had better thermal insulation with moisture and air permeability performance in both environments. The cardiopulmonary ventilation was 1.06 L higher (P < 0.01), and electromyographic amplitude was 4.64 µV lower at 15 °C and 6.59 µV lower at 30 °C (P < 0.05), indicating lower muscle fatigue. The microenvironment temperature of wearing thermoregulation pants was 0.2 °C higher at 15 °C, and 0.3 °C lower at 30 °C. Heart rate was significantly lower and blood oxygen saturation ranged from 98% to 100% (P < 0.05), which may be attributed to higher thermal resistance of 13.9 m2∙K∙10−3/W and moisture permeability of 30.5 g/m²/h of thermoregulation fabrics, reflecting better cardiopulmonary function during exercise. The temperature and humidity microenvironment were better than those of ordinary pants. Although there was no significant difference in thermoregulation, it had indeed a process of regulating temperature in both environments. The subjective sensory evaluation was consistent with the results of thermoregulation. This study helps to understand regulatory roles of thermoregulation fabrics in cold and hot environments, as well as impacts on human physiology and psychology, and effects of thermoregulation clothing on sport efficacy.

Sex-dependent shifts in body size and condition along replicated elevational gradients in a montane colonising ectotherm, the common wall lizard (Podarcis muralis).

In ectothermic animals, elevational gradients, such as mountainous environments, are often associated with shifts in body size, although patterns differ across taxa and contexts. Mountain landscapes are characterised by relatively rapid shifts in biotic and abiotic conditions along an elevational gradient, commonly referred to as elevational zonation. Such zonation can reduce the geographic scale at which organisms experience the effects of climate change. The upslope range shifts will expose organisms at the colonization front to sub-optimal conditions. We can expect these challenging conditions to influence many life-history traits including growth rates and reproductive output. We tested the hypothesis that body size varies across elevational gradients in a contemporary montane colonizer, the common wall lizard (Podarcis muralis). Further, we assessed active body temperatures and available environmental temperatures in an attempt to discern a potential abiotic factor that might drive such a pattern. We quantified body size in lizards along four replicate transects ranging from 400 to 2400m above sea level in the Pyrenees. Male body size decreased with increasing elevation. While female body size was invariant, females at higher elevation exhibited lower body condition. These results suggest that the effects of abiotic limitations or selective pressures experienced at the high-elevation colonisation front are sex-specific. Furthermore, lizards from both sexes were able to maintain similar field active body temperatures across elevation, despite reduced ambient temperature. If available temperatures limit activity periods or necessitate higher thermoregulatory investment, as suggested by our results, then further warming may benefit lizards and favour further upslope migration.

Productive Performance and Carcass Characteristics of Broiler Chickens Fed on Diets with Different Protein, Energy Levels, and Essential Oils During the Warm Season in Dry Tropics.

This study evaluated the productive performance and carcass traits of broiler chickens during the warm season in dry tropical conditions. Two hundred, 1-day-old chicks were used. Birds were fed on reduced (RED) and standard (STD) diets, and two essential oils (EOs) levels, 0 and 200 ppm. The RED diets were formulated with 10% less energy and 10% less protein than STD diets. In the starter phase, weight gain was greater (p < 0.01) in birds fed STD than birds fed RED. In the starter phase, productive variables were not affected (p ≥ 0.14) by EOs. In the finisher phase, greater feed intake (p = 0.02) and higher weight gain (p = 0.04) were observed in chickens on STD. Feed conversion ratio was similar (p = 0.97) for STD and RED. Throughout this study (1-42 d), greater feed intake (p = 0.02) and higher weight gain (p < 0.01) were found in chickens on STD. Feed conversion ratio was similar (p = 0.51) for STD and RED. Broiler chickens on EO-supplemented diets had better feed conversion (p ≥ 0.08). Hot carcass weight was greater (p < 0.01) in birds on STD. Greater yields of leg-thigh (p = 0.01), back (p = 0.01), and wings (p < 0.01) were observed in RED. Carcass yields, breast yield, pH, and meat temperature were not influenced (p ≥ 0.14) by nutrient concentrations in the diet. Carcass evaluations were not affected (p ≥ 0.11) by EOs. Body temperature was lower (p = 0.03) in birds receiving RED, however EOs had no effect (p ≥ 0.22) on body temperature. For the length of the study, at 20:00 h, broiler chickens fed on RED diets showed lower (p = 0.04) body temperatures. In conclusion, broiler chickens were under heat stress during the study, and body temperatures were reduced in chickens fed on RED diets or with EOs. Diet modification or EO-supplementation may improve feed conversion, though RED diets may have a negative effect on weight gain or carcass values.

Cooling down is as important as warming up for a large-bodied tropical reptile.

An ectotherm's performance and physiological function are strongly tied to environmental temperature, and many ectotherms thermoregulate behaviourally to reach optimum body temperatures. Tropical ectotherms are already living in environments matching their thermal tolerance range and may be expected to conform to environmental temperatures. We tracked the body temperatures (Tb) of 163 estuarine crocodiles across 13 years and compared Tb of 39 crocodiles to water temperature gathered using fish-borne sensors (Tw) across 3 years (2015-2018). While Tb largely conformed closely to Tw, we found inter- and intra-individual differences in relative body temperature (Tb-Tw) that depended on sex and body size as well as the time of day and year. Deviations from Tw, especially during the warm parts of the year, suggest that thermoregulatory behaviour was taking place: we found patterns of warming and cooling events that seemed to mediate this variation in Tb. Thermoregulatory behaviour was observed most frequently in larger individuals, with warming events common during winter and cooling events common during summer. By observing free-ranging animals across multiple years, we found that estuarine crocodiles show yearly patterns of active cooling and warming behaviours that modify their body temperature, highlighting their resilience in the face of recent climate warming. Our work also provides the first evidence for thermal type in large-bodied reptiles.

A stroke patient with persistently intermittent fever treated with gabapentin: A clinical case.

Fever is one of the most common complications in stroke patients and can generally be classified as either infectious or non-infectious. Infectious fevers are commonly caused by pulmonary infections, urinary tract infections, and secondary infections associated with medical interventions such as endotracheal intubation, urinary catheterization, and nasogastric tubes. Non-infectious fevers primarily manifest as central fevers, although in rare cases, they may also result from drug-induced causes. Existing research indicates that the most common cause of central fever is brainstem hemorrhage, followed by hemorrhage in the basal ganglia and thalamus, then cerebellar hemorrhage, large cortical infarction, and basilar artery occlusion, with intraventricular hemorrhage being relatively rare. Stroke patients' body temperatures can rise to 39°C within 12 hours after onset and peak within 24 hours. In this case, a stroke patient with acute cerebral infarction and secondary thalamic hemorrhage developed new sensory abnormalities in the left limbs and intermittent fever during hospitalization. Despite the use of antibiotics targeting a pulmonary infection, the patient's fever did not show significant improvement. Gabapentin was added to the treatment regimen to address the sensory abnormalities. Surprisingly, within four hours of gabapentin administration, the patient's body temperature normalized and remained stable during subsequent monitoring. This observation led us to hypothesize that gabapentin may have a potential role in alleviating central fever.

Thermoregulation and microhabitat use of Tachymenis peruviana (Dipsadidae) in semi-captivity conditions

Abstract We studied Tachymenis peruviana`s thermoregulatory strategy, and microhabitat use and selection in an open enclosure at 3400 m elevation during the wet season. We expected that thermal conditions at a high elevation locality would result in differences in the thermoregulatory efficiency within microhabitats through their use and selection along the day. We obtained preferred temperatures and critical thermal tolerance limits of field-captured individuals. Some individuals were kept in an open enclosure with access to four microhabitat types with retreats where to hide. We measured individuals’ field-body temperatures along with substrate and air temperatures, and recorded where the snakes were found according to microhabitat type and if they were inside or outside retreats. Meanwhile, operative temperatures were registered every hour at each offered microhabitat between 08:00 to 18:00 hours. The body and microenvironmental temperatures were highly correlated. Even though the enclosure offered appropriate thermal sources for snakes to reach their preferred temperatures, results indicate that the species met its energy requirements with a low effort in this high elevation enclosure. Almost three-quarters of the observations were recorded in retreat sites, showing a lower thermoregulatory efficiency compared to when they were captured aboveground. A comparative evaluation of the thermoregulation of the species in the field within a variety of thermal regimes experienced along its altitudinal and latitudinal range must still be carried out to better understand the species’ thermoregulatory strategies across the Andes.

Exploring the importance of predicted camel NRAP exon 4 for environmental adaptation using a mouse model.

Camels possess exceptional adaptability, allowing them to withstand extreme temperatures in desert environments. They conserve water by reducing their metabolic rate and regulating body temperature. The heart of the camel plays a crucial role in this adaptation, with specific genes expressed in cardiac tissue that are essential for mammalian adaptation, regulating cardiac function and responding to environmental stressors. One such gene, nebulin-related-anchoring protein (NRAP), is involved in the assembly of myofibrils and the transmission of force within the heart. In our study of the NRAP gene across various livestock species, including three camel species, we identified a camel-specific exon region in the NRAP transcripts. This additional exon (exon 4) contains an open reading frame predicted in camels. To investigate its function, we generated knock-in mice expressing camel NRAP exon 4. These 'camelized mice' exhibited normal phenotypic characteristics compared with wild-type mice but showed elevated body temperatures under cold stress. Transcriptome analyses of the hearts from camelized mice under cold stress revealed differentially expressed inflammatory cytokine genes, known to influence cardiac function by modulating the contractility of cardiac muscle cells. We propose further investigations utilizing these camelized mice to explore these findings in greater depth.

Stressful Body Temperatures as a Maternal Effect on Lizard Reproduction

Stressful Body Temperatures as a Maternal Effect on Lizard Reproduction

Effectiveness of Delayed First Baths on Transepidermal Water Loss in Late Preterm Infants: A Randomized Controlled Trial.

This study evaluates whether delaying the first bath affects late preterm infants' skin barriers, body temperatures, and comfort. Late preterm infants' skin is drier and has a limited water retention capacity compared to term infants and adults. It is important to determine timing of care for this population with limited competencies. A two-arm, three-center, and single- and evaluator-blind randomized controlled trial was conducted. The study is based on the CONSORT guidelines. The participants were recruited from September 2020 to September 2021. The first baths of participants in the intervention group were postponed until 48hours after birth. Outcomes were measured before bathing and 1, 10, and 30minutes after bathing. There was a statistically significant interaction between the groups and times for transepidermal water loss, body temperature, and comfort. The intervention group had a lower transepidermal water loss value at follow-up than the control group in the forearm and sternum. The control group had lower mean body temperatures and comfort levels. When the first bathing of a late preterm infant is postponed by a minimum of 48hours, it reduces damage to the skin barrier, body temperature is maintained, and the experience is more comfortable. Therefore, the first bath should be delayed for at least 48hours after birth. The study can guide nurses to eliminate the uncertainty of the first bath applied for late preterm infants with a fragile structure in the neonatal intensive care setting and to eliminate the differences between clinics.

Metabolic Compensation Associated With Digestion in Response to the Latitudinal Thermal Environment Across Populations of the Prairie Lizard (Sceloporus consobrinus).

Environmental temperatures directly affect physiological rates in ectotherms by constraining the possible body temperatures they can achieve, with physiological processes slowing as temperatures decrease and accelerating as temperatures increase. As environmental constraints increase, as they do northward along the latitudinal thermal gradient, organisms must adapt to compensate for the slower physiological processes or decreased opportunity time. Evolving faster general metabolic rates is one adaptive response posited by the metabolic cold adaptation (MCA) hypothesis. Here we test the MCA hypothesis by examining metabolism of prairie lizard populations across the latitudinal thermal gradient. Our results show that populations from cooler environments have higher standard metabolic rates (SMRs), but these are explained by associated larger body sizes. However, metabolic rates of fed, postprandial individuals (MRFed) and metabolic energy allocated to digestion (MRΔ) were highest in the population from the coldest environment after accounting for the effect of body size. Our results suggest cold-adapted populations compensate for lower temperatures and shorter activity periods by increasing metabolic rates associated with physiological processes and thus support the MCA hypothesis. When examining energy expenditure, metabolic rates of individuals in a postprandial state (MRFed) may be more ecologically relevant than those in a postabsorptive state (SMR) and give a better picture of energy use in ectotherm populations.

Drone-based infrared thermography to measure the intranasal temperature of baleen whales

ABSTRACT Traditional methods for quantifying the internal temperature of marine mammals require handling live animals, which is not practical for free-swimming baleen whales. Developing a less invasive, more repeatable method would significantly improve our understanding of whale health and thermal physiology. Infrared thermography (IRT) devices compatible with remotely piloted aircraft systems (RPAS) have facilitated qualitative assessments of heat signatures from marine mammals at sea, but absolute temperatures derived using this approach are rare. The goal of this study was to develop a precise empirical method for estimating intranasal temperatures of baleen whales using RPAS-based IRT. We conducted controlled field experiments and flights over North Atlantic right whales (Eubalaena glacialis, NARWs) to develop and test the methodology. Two approaches were evaluated to estimate intranasal temperatures from IRT sensor intensities: a three-point empirical line regression calibrated per flight using known-temperature objects and a generalized linear model incorporating environmental variables. Controlled field experiments demonstrated that the former approach had a median bias of −0.6°C (interquartile range: 1.5ºC), while the latter approach had unexplained negative proportional bias with increasing true temperature of the target object. After accounting for bias, the former approach yielded an average intranasal temperature of 26.9 ± 1.7°C for 21 unique NARWs. The anatomy of the mysticete upper respiratory tract and physiological heat conservation strategies may explain why estimates were low compared to internal temperatures measured from baleen whales using other techniques (30–39ºC). Variability within whales was less than ± 2°C, supporting the use of these methods to monitor the health of individuals over time. However, variability among whales was greater (up to 7ºC). Improvements in our understanding of whale physiology and respiratory mechanics and advancements in RPAS-based IRT calibrations could make this technology more reliable for assessing individual body temperatures and monitoring populations in the future.

Effects of Dihydroquercetin on the Intensity of Oxydative Stress in Rat Liver Mitochondria at Hypothermia

A decrease in body temperature in homeothermic animals can cause a state of the body called hypothermic. It is accompanied by the development of a number of pathological processes, many of which are associated with mitochondrial dysfunction and the development of oxidative stress. In connection with the widespread introduction of hypothermia into medical practice, the question of the possibility of a regulatory influence on the proxidant-antioxidant status of mitochondria at low body temperatures remains relevant. In recent years, plant polyphenols, in particular dihydroquercetin (DHQ), have gained wide popularity as therapeutic agents with antioxidant and membrane protective effects. In this work, we investigated the effects of DHQ on the intensity of oxidative stress in rat liver mitochondria under moderate hypothermia. It was found that a course (5 days) oral administration of DHA at a dose of 100 mg/kg significantly reduces the levels of LPO and OMP products in the liver mitochondria of control rats, increasing the content of non-enzymatic components of the thiol-disulfide antioxidant system`s. DHQ effectively protects liver mitochondria from the development of oxidative stress during hypothermia, as evidenced by a significant decrease (and in some cases, complete normalization) in the levels of diene conjugates, MDA, Schiff bases and carbonyl groups in a group of animals subjected to hypothermia with prior administration of this polyphenol. At the same time, DHQ significantly increases the levels of glutathione and vitamin E, and also normalizes the content of thiol groups in mitochondrial proteins. In vitro, DHQ exhibits a dose-dependent antioxidant effect, suppressing OMB in mitochondria incubated in Fenton's medium (IC50 = 0.160 mg/ml).