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We used thermal imagining and heat balance modelling to examine the thermal ecology of wild mammals, using the diurnal marsupial numbat (Myrmecobius fasciatus) as a model. Body surface temperature was measured using infra-red thermography at environmental wet and dry bulb temperatures of 11.7-29°C and 16.4-49.3°C, respectively; surface temperature varied for different body parts and with environmental temperature. Radiative and convective heat exchange varied markedly with environmental conditions and for various body surfaces reflecting their shapes, surface areas and projected areas. Both the anterior and posterior dorsolateral body areas functioned as thermal windows. Numbats in the shade had lower rates of solar radiative heat gain but non-solar avenues for radiative heat gain were substantial. Radiative gain was higher for black and lower for white stripes, but overall, the stripes had no thermal role. Total heat gain was generally positive (<4 to >20 W) and often greatly exceeded metabolic heat production (3-6 W). Our heat balance model indicates that high environmental heat loads limit foraging in open areas to as little as 10 min and that climate change may extend periods of inactivity, with implications for future conservation and management. We conclude that non-invasive thermal imaging is informative for modelling heat balance of free-living mammals.
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Marsupiales , Animales , Marsupiales/metabolismo , Regulación de la Temperatura Corporal , Calor , Temperatura Corporal , MamíferosRESUMEN
We identify for wild, free-living short-beaked echidnas (Tachyglossus aculeatus) a novel evaporative window, along with thermal windows, and demonstrate the insulating properties of the spines, using infrared thermography. The moist tip of their beak, with an underlying blood sinus, functions as a wet bulb globe thermometer, maximizing evaporative heat loss via an evaporative window. The ventral surface and insides of the legs are poorly insulated sites that act as postural thermal windows, while the spines provide flexible insulation (depending on piloerection). These avenues of heat exchange likely contribute to the higher-than-expected thermal tolerance of this species. Our study highlights how technological advances that allow for non-contact measurement of thermal variables allow us to better understand the physiological capacity of animals in their natural environment.
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Tachyglossidae , Animales , Tachyglossidae/fisiología , Ambiente , Regulación de la Temperatura Corporal , Calor , PicoRESUMEN
OBJECTIVE: The objective of this program evaluation was to describe the outcomes of daily neonatologist telerounding with the onsite advanced practice provider (APP) in a Level II neonatal intensive care unit (NICU), before and during the coronavirus disease 2019 (COVID-19) pandemic. STUDY DESIGN: Bedside telerounding occurred with an onsite APP using a telehealth cart and paired Bluetooth stethoscope. Data collected by longitudinal and cross-sectional surveys and chart review before (May 2019-February 2020) and during (March 2020-February 2021) the COVID-19 pandemic were analyzed using descriptive statistics and thematic analysis. RESULTS: A total of 258 patients were admitted to the Level II NICU before (May 2019-February 2020) and during (March 2020-February 2021) the COVID-19 pandemic. Demographic characteristics and outcomes, including breastfeeding at discharge and length of stay were similar pre- and postonset of the COVID-19 pandemic. Postrounding surveys by 10 (response rate 83%) neonatologists indicated parents were present in 80 (77%) of rounds and video was at least somewhat helpful in 94% of cases. Cross-sectional survey responses of 23 neonatologists and APPs (response rate 62%) indicated satisfaction with the program. Common themes on qualitative analysis of open-ended survey responses were "need for goodness of fit" and "another set of eyes" and "opportunities for use." CONCLUSION: Daily telerounding with neonatologists and APPs in a Level II NICU supported neonatal care. Quality metrics and clinical outcomes are described with no differences seen before and during the COVID-19 pandemic. KEY POINTS: · Little is known about Level II NICU quality metrics and outcomes.. · Daily bedside telerounding with neonatologists and APPs is described.. · Telerounding supported neonatal care before and during the COVID-19 pandemic.. · Neonatologists found visual exam helpful in the majority of cases.. · No differences in NICU clinical outcomes were seen during the COVID-19 pandemic..
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We examine here the effects on evaporative water loss, at and below thermoneutrality, of perturbing the evaporative environment for the red-capped parrot (Purpureicephalus spurius) by modifying the ambient relative humidity or the diffusive properties of the ambient environment using a heliumoxygen mix (helox). We found that evaporative water loss did not change with relative humidity at an ambient temperature of 30 °C, but there was a negative relationship for evaporative water loss with relative humidity at 20 and 25 °C. The evaporative water loss per water vapour pressure deficit between the bird and its ambient environment was not constant with relative humidity, as would be expected for a physical effect (slope = 0); rather there was a significant positive relationship with relative humidity at ambient temperatures of 25 and 30 °C. Consequently, we conclude that the red-capped parrot can physiologically control its EWL over a range of relative humidities. For the first time for a bird species, we also confirmed EWL control using a second methodology to perturb the evaporative environment, and demonstrated that a more diffusive helox atmosphere has no effect on evaporative water loss of live birds, but evaporative water loss was higher for dead birds in helox compared to air. Our results for evaporative water loss and other physiological variables for red-capped parrots are consistent with the hypothesis that evaporative water loss is under physiological control.
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Regulación de la Temperatura Corporal/fisiología , Loros/fisiología , Pérdida Insensible de Agua/fisiología , Animales , Femenino , Humedad , Masculino , Conductividad TérmicaRESUMEN
Background:Video telehealth is an important tool for health care delivery during the COVID-19 pandemic. Given physical distancing recommendations, access to traditional in-person telehealth training for providers has been limited. Telesimulation is an alternative to in-person telehealth training. Telesimulation training with both remote participants and facilitators using telehealth software has not been described.Objective:We investigated the feasibility of a large group telesimulation provider training of telehealth software for remote team leadership skills with common neonatal cases and procedures.Methods:We conducted a 90-min telesimulation session with a combination of InTouch™ provider access software and Zoom™ teleconferencing software. Zoom facilitators activated InTouch software and devices and shared their screen with remote participants. Participants rotated through skill stations and case scenarios through Zoom and directed bedside facilitators to perform simulated tasks using the shared screen and audio connection. Participants engaged in a debrief and a pre- and postsurvey assessing participants' comfort and readiness to use telemedicine. Data were analyzed using descriptive statistics and paired t tests.Results:Twenty (n = 20) participants, five Zoom and eight bedside facilitators participated. Twenty-one (21) pre- and 16 postsurveys were completed. Most participants were attending neonatologists who rarely used telemedicine software. Postsession, participants reported increased comfort with some advanced InTouch features, including taking and sharing pictures with the patient (p < 0.01) and drawing on the shared image (p < 0.05), but less comfort with troubleshooting technical issues, including audio and stethoscope (p < 0.01). Frequently stated concerns were troubleshooting technical issues during a call (75%, n = 16) and personal discomfort with telemedicine applications and technology (56%, n = 16).Conclusion:Large group telesimulation is a feasible way to offer telehealth training for physicians and can increase provider comfort with telehealth software.
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COVID-19 , Telemedicina , Estudios de Factibilidad , Humanos , Recién Nacido , Pandemias , SARS-CoV-2RESUMEN
We present two independent lines of evidence that a tiny dasyurid marsupial, the ningaui (Ningaui spp.), has acute physiological control of its insensible evaporative water loss below and within thermoneutrality. Perturbation of the driving force for evaporation by varying relative humidity, and therefore the water vapour pressure deficit between the animal and the ambient air, does not have the expected physical effect on evaporative water loss. Exposure to a helox atmosphere also does not have the expected physical effect of increasing evaporative water loss for live ningauis (despite it having the expected effect of increasing heat loss for live ningauis), but increases evaporative water loss for dead ningauis. We discuss the relative advantages and disadvantages of both experimental approaches for demonstrating physiological control of insensible evaporative water loss. An appreciation of physiological control is important because insensible evaporative water loss contributes to both water and heat balance, is clearly under environmental selection pressure, and potentially impacts the distribution of endotherms and their response to environmental change.
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Marsupiales , Animales , Regulación de la Temperatura Corporal , Calor , Humedad , Agua , Pérdida Insensible de AguaRESUMEN
Insensible evaporative water loss (EWL) at or below thermoneutrality is generally assumed to be a passive physical process. However, some arid zone mammals and a single arid zone bird can control their insensible water loss, so we tested the hypothesis that the same is the case for two parrot species from a mesic habitat. We investigated red-rumped parrots (Psephotus haematonotus) and eastern rosellas (Platycercus eximius), measuring their EWL, and other physiological variables, at a range of relative humidities at ambient temperatures of 20 and 30°C (below and at thermoneutrality). We found that, despite a decrease in EWL with increasing relative humidity, rates of EWL were not fully accounted for by the water vapour deficit between the animal and its environment, indicating that the insensible EWL of both parrots was controlled. It is unlikely that this deviation from physical expectations was regulation with a primary role for water conservation because our mesic-habitat parrots had equivalent regulatory ability as the arid habitat budgerigar (Melopsittacus undulatus). This, together with our observations of body temperature and metabolic rate, instead support the hypothesis that acute physiological control of insensible water loss serves a thermoregulatory purpose for endotherms. Modification of both cutaneous and respiratory avenues of evaporation may be involved, possibly via modification of expired air temperature and humidity, and surface resistance.
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Loros , Pérdida Insensible de Agua , Animales , Regulación de la Temperatura Corporal , Temperatura , AguaRESUMEN
Desert birds inhabit hot, dry environments that are becoming hotter and drier as a consequence of climate change. Extreme weather such as heatwaves can cause mass-mortality events that may significantly impact populations and species. There are currently insufficient data concerning physiological plasticity to inform models of species' response to extreme events and develop mitigation strategies. Consequently, we examine here the physiological plasticity of a small desert bird in response to hot (mean maximum ambient temperature=42.7°C) and cooler (mean maximum ambient temperature=31.4°C) periods during a single Austral summer. We measured body mass, metabolic rate, evaporative water loss and body temperature, along with blood parameters (corticosterone, glucose and uric acid) of wild zebra finches (Taeniopygia guttata) to assess their physiological state and determine the mechanisms by which they respond to heatwaves. Hot days were not significant stressors; they did not result in modification of baseline blood parameters or an inability to maintain body mass, provided drinking water was available. During heatwaves, finches shifted their thermoneutral zone to higher temperatures. They reduced metabolic heat production, evaporative water loss and wet thermal conductance, and increased hyperthermia, especially when exposed to high ambient temperature. A consideration of the significant physiological plasticity that we have demonstrated to achieve more favourable heat and water balance is essential for effectively modelling and planning for the impacts of climate change on biodiversity.
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Pinzones , Calor , Animales , Temperatura Corporal , Regulación de la Temperatura Corporal , Estaciones del Año , TemperaturaRESUMEN
It is unclear whether torpor really is uncommon amongst passerine birds. We therefore examined body temperature and thermoregulatory strategies of an Austral passerine, the white-browed babbler (Pomatostomus superciliosus), which has characteristics related to a high probability of torpor use; it is a sedentary, insectivorous, cooperative breeding species, which we studied during winter in a temperate habitat. Wild, free-living babblers maintained normothermy overnight, even at sub-zero ambient temperatures, with a mean minimum body temperature of 38.5±0.04°C that was independent of minimum black bulb temperature. Physiological variables measured in the laboratory revealed that babblers had a low basal metabolic rate and evaporative water loss, but their body temperature and thermal conductance were typical of those of other birds and they had a typical endothermic response to low ambient temperature. Huddling yielded significant energy savings at low temperatures and a roost nest created a microclimate that buffered against low temperatures. Low basal energy requirements, communal roosting and the insulation of a roost nest confer sufficient energetic benefits, allowing babblers to meet energy requirements without resorting to heterothermia, even in their depauperate, low-productivity landscape, suggesting that passerine birds use alternatives to torpor to balance their energy budgets when possible.
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Regulación de la Temperatura Corporal , Passeriformes/fisiología , Letargo , Animales , Metabolismo Basal , Temperatura Corporal , Estaciones del AñoRESUMEN
'Insensible' evaporative water loss of mammals has been traditionally viewed as a passive process, but recent studies suggest that insensible water loss is under regulatory control, although the physiological role of this control is unclear. We test the hypothesis that regulation of insensible water loss has a thermoregulatory function by quantifying for the first time evaporative water loss control, along with metabolic rate and body temperature, of a heterothermic mammal during normothermia and torpor. Evaporative water loss was independent of ambient relative humidity at ambient temperatures of 20 and 30°C, but not at 25°C or during torpor at 20°C. Evaporative water loss per water vapour pressure deficit had a positive linear relationship with relative humidity at ambient temperatures of 20 and 30°C, but not at 25°C or during torpor at 20 or 25°C. These findings suggest that insensible water loss deviates from a physical model only during thermoregulation, providing support for the hypothesis that regulation of insensible evaporative water loss has a thermoregulatory role.
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Regulación de la Temperatura Corporal/fisiología , Marsupiales/fisiología , Pérdida Insensible de Agua/fisiología , Animales , Metabolismo Energético/fisiología , Australia OccidentalRESUMEN
Many Australian tetrapods inhabit desert environments characterised by low productivity, unpredictable rainfall, high temperatures and high incident solar radiation. Maintaining a homeostatic milieu intérieur by osmoregulation and thermoregulation are two physiological challenges faced by tetrapods in deserts, and the endocrine system plays an important role in regulating these processes. There is a considerable body of work examining the osmoregulatory role of antidiuretic hormones for Australian amphibians, reptiles and mammals, with particular contributions concerning their role and function for wild, free-living animals in arid environments. The osmoregulatory role of the natriuretic peptide system has received some attention, while the role of adrenal corticosteroids has been more thoroughly investigated for reptiles and marsupials. The endocrinology of thermoregulation has not received similar attention. Reptiles are best-studied, with research examining the influence of arginine vasotocin and melatonin on body temperature, the role of prostaglandins in heart rate hysteresis and the effect of melanocyte-stimulating hormone on skin reflectivity. Australian mammals have been under-utilised in studies examining the regulation, development and evolution of endothermy, and there is little information concerning the endocrinology of thermoregulation for desert species. There is a paucity of data concerning the endocrinology of osmoregulation and thermoregulation for Australian desert birds. Studies of Australian desert fauna have made substantial contributions to endocrinology, but there is considerable scope for further research. A co-ordinated approach to examine arid-habitat adaptations of the endocrine system in an environmental and evolutionary context would be of particular value.
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Regulación de la Temperatura Corporal/fisiología , Clima Desértico , Vertebrados/fisiología , Equilibrio Hidroelectrolítico/fisiología , Animales , AustraliaRESUMEN
Fires have occurred throughout history, including those associated with the meteoroid impact at the Cretaceous-Palaeogene (K-Pg) boundary that eliminated many vertebrate species. To evaluate the recent hypothesis that the survival of the K-Pg fires by ancestral mammals was dependent on their ability to use energy-conserving torpor, we studied body temperature fluctuations and activity of an egg-laying mammal, the echidna (Tachyglossus aculeatus), often considered to be a 'living fossil', before, during and after a prescribed burn. All but one study animal survived the fire in the prescribed burn area and echidnas remained inactive during the day(s) following the fire and substantially reduced body temperature during bouts of torpor. For weeks after the fire, all individuals remained in their original territories and compensated for changes in their habitat with a decrease in mean body temperature and activity. Our data suggest that heterothermy enables mammals to outlast the conditions during and after a fire by reducing energy expenditure, permitting periods of extended inactivity. Therefore, torpor facilitates survival in a fire-scorched landscape and consequently may have been of functional significance for mammalian survival at the K-Pg boundary.
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Incendios , Longevidad , Tachyglossidae/fisiología , Letargo , Animales , Temperatura CorporalRESUMEN
The short-beaked echidna (Tachyglossus aculeatus) is a monotreme and therefore provides a unique combination of phylogenetic history, morphological differentiation and ecological specialisation for a mammal. The echidna has a unique appendicular skeleton, a highly specialised myrmecophagous lifestyle and a mode of locomotion that is neither typically mammalian nor reptilian, but has aspects of both lineages. We therefore were interested in the interactions of locomotor biomechanics, ecology and movements for wild, free-living short-beaked echidnas. To assess locomotion in its complex natural environment, we attached both GPS and accelerometer loggers to the back of echidnas in both spring and summer. We found that the locomotor biomechanics of echidnas is unique, with lower stride length and stride frequency than reported for similar-sized mammals. Speed modulation is primarily accomplished through changes in stride frequency, with a mean of 1.39â Hz and a maximum of 2.31â Hz. Daily activity period was linked to ambient air temperature, which restricted daytime activity during the hotter summer months. Echidnas had longer activity periods and longer digging bouts in spring compared with summer. In summer, echidnas had higher walking speeds than in spring, perhaps because of the shorter time suitable for activity. Echidnas spent, on average, 12% of their time digging, which indicates their potential to excavate up to 204â m3 of soil a year. This information highlights the important contribution towards ecosystem health, via bioturbation, of this widespread Australian monotreme.
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Acelerometría , Ecosistema , Sistemas de Información Geográfica , Tachyglossidae/fisiología , Animales , Fenómenos Biomecánicos , Peso Corporal , Estaciones del Año , Especificidad de la Especie , Caminata/fisiologíaRESUMEN
BACKGROUND: Over the past several years, the concept of prodromal Parkinson disease (PD) has been increasingly recognized. This term refers to individuals who do not fulfill motor diagnostic criteria for PD, but who have clinical, genetic, or biomarker characteristics suggesting risk of developing PD in the future. Clinical diagnosis of prodromal PD has low specificity, prompting the need for objective biomarkers with higher specificity. In this qualitative review, we discuss objectively defined putative biomarkers for PD and prodromal PD. METHODS: We searched Pubmed and Embase for articles pertaining to objective biomarkers for PD and their application in prodromal cohorts. Articles were selected based on relevance and methodology. KEY FINDINGS: Objective biomarkers of demonstrated utility in prodromal PD include ligand-based imaging and transcranial sonography. Development of serum, cerebrospinal fluid, and tissue-based biomarkers is underway, but their application in prodromal PD has yet to meaningfully occur. Combining objective biomarkers with clinical or genetic prodromal features increases the sensitivity and specificity for identifying prodromal PD. CONCLUSIONS: Several objective biomarkers for prodromal PD show promise but require further study, including their application to and validation in prodromal cohorts followed longitudinally. Accurate identification of prodromal PD will likely require a multimodal approach. (JINS, 2016, 22, 956-967).
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Biomarcadores , Enfermedad de Parkinson/diagnóstico , Síntomas Prodrómicos , HumanosRESUMEN
Interruptions decrease the efficiency of the medication administration process. In this study, interruptions were found in 63% of the medication passes on four medical-surgical units in a community hospital. However, interruptions do not always lead to negative outcomes.
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Atención , Quimioterapia/enfermería , Errores de Medicación/prevención & control , Preparaciones Farmacéuticas/administración & dosificación , Hospitales Comunitarios , Humanos , IllinoisRESUMEN
It is a central paradigm of comparative physiology that the effect of humidity on evaporative water loss (EWL) is determined for most mammals and birds, in and below thermoneutrality, essentially by physics and is not under physiological regulation. Fick's law predicts that EWL should be inversely proportional to ambient relative humidity (RH) and linearly proportional to the water vapour pressure deficit (Δwvp) between animal and air. However, we show here for a small dasyurid marsupial, the little kaluta (Dasykaluta rosamondae), that EWL is essentially independent of RH (and Δwvp) at low RH (as are metabolic rate and thermal conductance). These results suggest regulation of a constant EWL independent of RH, a hitherto unappreciated capacity of endothermic vertebrates. Independence of EWL from RH conserves water and heat at low RH, and avoids physiological adjustments to changes in evaporative heat loss such as thermoregulation. Re-evaluation of previously published data for mammals and birds suggests that a lesser dependence of EWL on RH is observed more commonly than previously thought, suggesting that physiological independence of EWL of RH is not just an unusual capacity of a few species, such as the little kaluta, but a more general capability of many mammals and birds.
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Regulación de la Temperatura Corporal , Metabolismo Energético , Marsupiales/fisiología , Pérdida Insensible de Agua , Animales , Femenino , Humedad , Masculino , Temperatura , Australia OccidentalRESUMEN
Total evaporative water loss of endotherms is assumed to be determined essentially by biophysics, at least at temperatures below thermoneutrality, with evaporative water loss determined by the water vapor deficit between the animal and the ambient air. We present here evidence, based on the first measurements of evaporative water loss for a small mammal in heliox, that mammals may have a previously unappreciated ability to maintain acute constancy of total evaporative water loss under perturbing environmental conditions. Thermoregulatory responses of ash-grey mice (Pseudomys albocinereus) to heliox were as expected, with changes in metabolic rate, conductance, and respiratory ventilation consistent with maintaining constancy of body temperature under conditions of enhanced heat loss. However, evaporative water loss did not increase in heliox. This is despite our confirmation of the physical effect that heliox augments evaporation from nonliving surfaces, which should increase cutaneous water loss, and increases minute volume of live ash-grey mice in heliox to accommodate their elevated metabolic rate, which should increase respiratory water loss. Therefore, mice had not only a thermoregulatory but also a hygroregulatory response to heliox. We interpret these results as evidence that ash-grey mice can acutely control their evaporative water loss under perturbing environmental conditions and suggest that hygroregulation at and below thermoneutrality is an important aspect of the physiology of at least some small mammals.
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Ambiente , Helio/farmacología , Murinae/fisiología , Oxígeno/farmacología , Pérdida Insensible de Agua/efectos de los fármacos , Animales , Metabolismo Basal/fisiología , Temperatura Corporal/fisiología , Metabolismo Energético/fisiología , Masculino , Ratones , Modelos Animales , Pérdida Insensible de Agua/fisiologíaRESUMEN
We present a presumptive case of metastatic carcinoma in an individual from the 11th/12th century CE from Vaduz, Principality of Liechtenstein. The skeleton exhibits extensive new bone formation in the axial skeleton and the proximal humerus and femur. Radiological examinations revealed further sclerotic lesions in the clavicles, the manubrium, the sternum, the femoral diaphysis, and possibly the frontal. The pelvic bones and the sacrum, as well as the spine, are the most heavily affected skeletal regions. The newly formed bone in some lesions has a "sun-burst" appearance. The sex and age at death of the individual, the distribution and the osteoblastic nature of the lesions suggest that prostate carcinoma is the most likely primary tumor.
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Neoplasias Óseas , Humanos , Historia Medieval , Masculino , Neoplasias Óseas/historia , Neoplasias Óseas/patología , Neoplasias de la Próstata/patología , Neoplasias de la Próstata/historiaRESUMEN
BACKGROUND: Up to 10 % of Parkinson's disease (PD) populations carry a genetic risk variant, which may not only increase one's chance of developing PD but also affect disease presentation and progression. We hypothesize motor impairment in genetic carriers of PD correlate to different patterns of microstructural changes over time. DESIGN/METHODS: Data were accessed from the Parkinson's Progression Markers Initiative (PPMI) project. Connectometry analyses were performed for GBA1+ PD, LRRK2+ PD, and sporadic PD correlating white matter structural changes, as measured by quantitative anisotropy (QA), with motor impairment, as measured by MDS-UPDRS III. RESULTS: There was a negative correlation between QA and MDS-UPDRS III in all 3 cohorts at 48 months. In GBA1+ PD (n = 12), the white matter tracts identified were cortical and subcortical, while in the LRRK2+ PD (n = 18) and sporadic PD (n = 45) cohorts white tracts identified were primarily subcortical and within the brainstem. CONCLUSIONS: Our findings highlight the association between motor symptom progrerssion and structural connectivity in individuals with GBA1+ PD, LRRK2+ PD, and sporadic PD. Due to the small sample size, larger studies are needed in the future to confirm the findings.
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Thermoregulation is critical for endotherms living in hot, dry conditions, and maintaining optimal core body temperature (Tb) in a changing climate is an increasingly challenging task for mammals. Koalas (Phascolarctos cinereus) have evolved physiological and behavioural strategies to maintain homeostasis and regulate their Tb but are thought to be vulnerable to prolonged heat. We investigated how weather, behaviour and disease influence Tb for wild, free-living koalas during summer in north-west New South Wales. We matched Tb with daily behavioural observations in an ageing population where chlamydial disease is prevalent. Each individual koala had similar Tb rhythms (average Tb = 36.4 ± 0.05°C), but male koalas had higher Tb amplitude and more pronounced daily rhythm than females. Disease disrupted the 24-hr circadian pattern of Tb. Koala Tb increased with ambient temperature (Ta). On the hottest day of the study (maximum Ta = 40.8°C), we recorded the highest (Tb = 40.8°C) but also the lowest (Tb = 32.4°C) Tb ever documented for wild koalas, suggesting that they are more heterothermic than previously recognized. This requires individuals to predict days of extreme Ta from overnight and early morning conditions, adjusting Tb regulation accordingly, and it has never been reported before for koalas. The large diel amplitude and low minimum Tb observed suggest that koalas at our study site are energetically and nutritionally compromised, likely due to their age. Behaviour (i.e. tree hugging and drinking water) was not effective in moderating Tb. These results indicate that Ta and koala Tb are strongly interconnected and reinforce the importance of climate projections for predicting the future persistence of koalas throughout their current distribution. Global climate models forecast that dry, hot weather will continue to escalate and drought events will increase in frequency, duration and severity. This is likely to push koalas and other arboreal folivores towards their thermal limit.