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1.
Conserv Physiol ; 12(1): coae032, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38803425

RESUMO

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.

2.
Anthropol Anz ; 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38445726

RESUMO

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.

3.
J Exp Biol ; 227(1)2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38206870

RESUMO

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.


Assuntos
Marsupiais , Animais , Marsupiais/metabolismo , Regulação da Temperatura Corporal , Temperatura Alta , Temperatura Corporal , Mamíferos
4.
BMC Res Notes ; 16(1): 370, 2023 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-38111014

RESUMO

OBJECTIVE: Roller swabbing of surfaces is an effective way to obtain environmental DNA, but the current DNA extraction method for these samples is equipment heavy, time consuming, and increases potential contamination through multiple handling. Here, we used rollers to swab a dog kennel and compared three DNA extraction approaches (water filtration, roller trimming and direct buffer) using two different platforms (Qiacube, Kingfisher). DNA extraction methods were evaluated based on cost, effort, DNA concentration and PCR result. RESULTS: The roller trim method emerged as the optimal method with the best PCR results, DNA concentration and cost efficiency, while the buffer-based methods were the least labour intensive but produced mediocre PCR results and DNA concentrations. Additionally, the Kingfisher magnetic bead extractions generally ranked higher in all categories over the Qiacube column-based DNA extractions. Ultimately, the ideal DNA extraction method for a particular study is influenced by logistical constraints in the field such as the size of the roller, the availability of cold storage, and time constraints on the project. Our results demonstrate the strengths and weaknesses of each approach, allowing for informed decision making by researchers.


Assuntos
DNA Ambiental , Animais , Cães , DNA/genética , Reação em Cadeia da Polimerase , Água , Técnicas de Amplificação de Ácido Nucleico
5.
Front Hum Neurosci ; 17: 1271046, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38021224

RESUMO

Background: Although ET is a phenomenologically heterogeneous condition, thalamic DBS appears to be equally effective across subtypes. We hypothesized stimulation sites optimized for individuals with essential tremor (ET) would differ from individuals with essential tremor plus syndrome (ET-plus). We examined group differences in optimal stimulation sites within the ventral thalamus and their overlap of with relevant white matter tracts. By capturing these differences, we sought to determine whether ET subtypes are associated with anatomically distinct neural pathways. Methods: A retrospective chart review was conducted on ET patients undergoing VIM DBS at MUSC between 01/2012 and 02/2022. Clinical, demographic, neuroimaging, and DBS stimulation parameter data were collected. Clinical characteristics and pre-DBS videos were reviewed to classify ET and ET-plus cohorts. Patients in ET-plus cohorts were further divided into ET with dystonia, ET with ataxia, and ET with others. DBS leads were reconstructed using Lead-DBS and the volume of tissue activated (VTA) overlap was performed using normative connectomes. Tremor improvement was measured by reduction in a subscore of tremor rating scale (TRS) post-DBS lateralized to the more affected limb. Results: Sixty-eight ET patients were enrolled after initial screening, of these 10 ET and 24 ET-plus patients were included in the final analyses. ET group had an earlier age at onset (p = 0.185) and underwent surgery at a younger age (p = 0.096). Both groups achieved effective tremor control. No significant differences were found in lead placement or VTA overlap within ventral thalamus. The VTA center of gravity (COG) in the ET-plus cohort was located dorsal to that of the ET cohort. No significant differences were found in VTA overlap with the dentato-rubral-thalamic (DRTT) tracts or the ansa lenticularis. Dystonia was more prevalent than ataxia in the ET-plus subgroups (n = 18 and n = 5, respectively). ET-plus with dystonia subgroup had a more medial COG compared to ET-plus with ataxia. Conclusion: VIM DBS therapy is efficacious in patients with ET and ET-plus. There were no significant differences in optimal stimulation site or VTA overlap with white-matter tracts between ET, ET-plus and ET-plus subgroups.

6.
Ecol Evol ; 13(10): e10598, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37818246

RESUMO

The use of anthropogenic resources is becoming increasingly common as species adapt to human-induced environmental changes, but their use can expose species to new risks. Understanding how animals exploit these resources is important for guiding conservation management, particularly where species are threatened. The introduction of canola cropping to breeding areas of endangered Carnaby's cockatoo (Zanda latirostris) has been attributed to an increase in the birds' reproductive success; however, the seed may be protein-limiting for nestling growth and its use by cockatoos has been implicated in the emergence of a new disease. We used high-resolution accelerometer-capable GPS tags to track eight birds. Accelerometer data were used to calculate overall dynamic body acceleration (ODBA), a proxy for energy expenditure, and to identify and quantify canola and native vegetation foraging behaviours. We used linear mixed models to determine which factors affected patterns of resource use and to determine whether, and to what extent, canola use was associated with reduced energetic and movement costs. We then compared the energetic content of canola seed and native food sources to inform patterns of behaviour and habitat use revealed by our tracking data. Use of canola was associated with reduced movement costs and energy expenditure. However, there was an apparent reluctance to increase foraging on canola above a threshold of time, even when conditions reduced time available to utilise native food sources. While anthropogenic resources may appear to improve population trends in some cases, careful investigations of patterns of resource use are necessary to guide appropriate conservation management efforts. For Carnaby's cockatoos, conservation efforts should focus on retention, protection and expansion of native food sources.

7.
R Soc Open Sci ; 10(10): 230325, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37800154

RESUMO

Mammalian fluorescence has been reported from numerous species of monotreme, marsupial and placental mammal. However, it is unknown how widespread this phenomenon is among mammals, it is unclear for many species if these observations of 'glowing' are true fluorescence and the biological function of fluorescence remains undetermined. We examined a wide range of mammal species held in a museum collection for the presence of apparent fluorescence using UV light, and then analysed a subset of preserved and non-preserved specimens by fluorescent spectroscopy at three different excitation wavelengths to assess whether the observations were fluorescence or optical scatter, and the impact of specimen preservation. We also evaluated if fluorescence was related to biological traits. We found that fluorescence is widespread in mammalian taxa; we identified examples of the phenomena among 125 species representing all 27 living mammalian orders and 79 families. For a number of model species, there was no evidence of a corresponding shift in the emission spectra when the wavelength of excitation was shifted, suggesting that observations of 'glowing' mammals were indeed fluorescence. Preservation method impacted the intensity of fluorescence. Fluorescence was most common and most intense among nocturnal species and those with terrestrial, arboreal and fossorial habits, with more of their body being more fluorescent. It remains unclear if fluorescence has any specific biological role for mammals. It appears to be a ubiquitous property of unpigmented fur and skin but may function to make these areas appear brighter and therefore enhance visual signalling, especially for nocturnal species.

8.
Archaeol Anthropol Sci ; 15(9): 137, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37635748

RESUMO

The Iron Age in continental Europe is a period of profound cultural and biological importance with heterogeneous trends through space and time. Regional overviews are therefore useful for better understanding the main cultural and biological patterns characterizing this period across the European regions. For the area of modern Switzerland, a rich archeological and anthropological record represents the Late Iron Age. However, no review of the main anthropological and funerary patterns for this period is available to date. Here we assess the available demographic, paleopathological, funerary, and isotopic data for the Late Iron Age in the Swiss territory, and summarize the cultural and biological patterns emerging from the available literature. Finally, we highlight a series of research avenues for future studies.

9.
Am J Perinatol ; 2023 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-37348545

RESUMO

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..

10.
Ecol Evol ; 13(4): e10014, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37113520

RESUMO

Biomonitoring is vital for establishing baseline data that is needed to identify and quantify ecological change and to inform management and conservation activities. However, biomonitoring and biodiversity assessment in arid environments, which are predicted to cover 56% of the Earth's land surface by 2100, can be prohibitively time consuming, expensive, and logistically challenging due to their often remote and inhospitable nature. Sampling of environmental DNA (eDNA) coupled with high-throughput sequencing is an emerging biodiversity assessment method. Here we explore the application of eDNA metabarcoding and various sampling approaches to estimate vertebrate richness and assemblage at human-constructed and natural water sources in a semi-arid region of Western Australia. Three sampling methods: sediment samples, filtering through a membrane with a pump, and membrane sweeping in the water body, were compared using two eDNA metabarcoding assays, 12S-V5 and 16smam, for 120 eDNA samples collected from four gnammas (gnamma: Australian Indigenous Noongar language term-granite rock pools) and four cattle troughs in the Great Western Woodlands, Western Australia. We detected higher vertebrate richness in samples from cattle troughs and found differences between assemblages detected in gnammas (more birds and amphibians) and cattle troughs (more mammals, including feral taxa). Total vertebrate richness was not different between swept and filtered samples, but all sampling methods yielded different assemblages. Our findings indicate that eDNA surveys in arid lands will benefit from collecting multiple samples at multiple water sources to avoid underestimating vertebrate richness. The high concentration of eDNA in small, isolated water bodies permits the use of sweep sampling that simplifies sample collection, processing, and storage, particularly when assessing vertebrate biodiversity across large spatial scales.

11.
Biol Lett ; 19(1): 20220495, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36651031

RESUMO

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.


Assuntos
Tachyglossidae , Animais , Tachyglossidae/fisiologia , Meio Ambiente , Regulação da Temperatura Corporal , Temperatura Alta , Bico
12.
Physiother Theory Pract ; 39(9): 1938-1951, 2023 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-35383528

RESUMO

BACKGROUND: Chronic pain and pain catastrophization are growing problems across the United States, within the Hispanic-American population. Pain neuroscience education (PNE) changes pain knowledge and beliefs in many populations, but its impact on reconceptualization in people of Hispanic-American origin is unknown. PURPOSE: Explore the changes in pain knowledge in Hispanic-American individuals and the process involved in reconceptualization following a PNE lecture. METHODS: Eight Hispanic-American adults participated in a mixed-methods exploratory study. The Revised Neurophysiology of Pain Questionnaire (R-NPQ) was completed before, immediately after, and eight months after an adapted PNE lecture. A focus group involving four participants discussed the impact of PNE. Transcripts were translated and theme coded, and a concept map was developed by consensus. RESULTS: R-NPQ scores improved from 25.3% to 43.5% post-lecture, and the number of unsure responses decreased from 41.5% to 18.4%. At eight months, R-NPQ scores remained stable (44.2%) but unsure responses increased (28.9%). Themes that contributed to the process of change included cognitive dissonance, relevance of instruction, idea exchange through peer interaction, reflection, confidence, changed behaviors, and educational utility. CONCLUSION: While small improvements in knowledge and perception of pain appeared to occur with the PNE, knowledge remained low. Consideration of adult learning principles such as applicability, peer-interaction, the confrontation of beliefs, and reflection throughout PNE may enhance its impact. Future investigation should explore the efficacy of this intervention, when compared or combined with other techniques in the treatment of Hispanic-Americans experiencing persistent pain.


Assuntos
Dor Crônica , Neurociências , Adulto , Humanos , Dor Crônica/diagnóstico , Dor Crônica/terapia , Manejo da Dor/métodos , Aprendizagem , Neurociências/educação , Inquéritos e Questionários
13.
Conserv Physiol ; 10(1): coac010, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35492422

RESUMO

Conradie et al. (2020) recently modelled the vulnerability of Australian arid birds to a changing climate. While the approach used by Conradie et al. (2020) is valuable, we argue that key assumptions in their study are poorly supported and the risks of a changing climate to arid zone avifauna are consequently overstated.

14.
Physiol Biochem Zool ; 95(3): 212-228, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35437120

RESUMO

AbstractWe show here that evaporative water loss (EWL) is constant over a wide range of ambient relative humidity for two species of small, mesic habitat dasyurid marsupials (Antechinus agilis and Antechinus swainsonii) below thermoneutrality (20°C) and within thermoneutrality (30°C). This independence of EWL from the water vapor pressure deficit between the animal and its environment indicates that EWL is physiologically controlled by both species. The magnitude of this control of EWL was similar to that of two other small marsupials from more arid habitats, which combined with the observation that there were no effects of relative humidity on body temperature or metabolic rate, suggests that control of EWL is a consequence of precise thermoregulation to maintain heat balance rather than a water-conserving strategy at low relative humidities. The antechinus appear to manipulate cutaneous EWL rather than respiratory EWL to control their total EWL by modifying their cutaneous resistance and/or skin temperature. We propose that there is a continuum between enhanced thermoregulatory EWL at high ambient temperature and so-called insensible EWL at and below thermoneutrality.


Assuntos
Conservação dos Recursos Hídricos , Marsupiais , Animais , Temperatura Corporal/fisiologia , Regulação da Temperatura Corporal/fisiologia , Marsupiais/fisiologia , Perda Insensível de Água/fisiologia
15.
Artigo em Inglês | MEDLINE | ID: mdl-34298193

RESUMO

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.


Assuntos
Regulação da Temperatura Corporal/fisiologia , Papagaios/fisiologia , Perda Insensível de Água/fisiologia , Animais , Feminino , Umidade , Masculino , Condutividade Térmica
16.
Front Physiol ; 12: 661670, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33986695

RESUMO

Human-induced climate change is increasing the frequency, duration, and intensity of heat waves and exposure to these extreme temperatures impacts individual physiology and performance (e.g., metabolism, water balance, and growth). These traits may be susceptible to thermal conditions experienced during embryonic development, but experiments focusing on post-natal development are scant. Documented effects of heat waves on whole-body metabolism may reflect changes in mitochondrial function, but most studies do not measure physiological traits at both the cellular and whole organism levels. Here, we exposed nests of zebra finches to experimentally simulated heat waves for 18 days after hatching and measured body mass, growth rate, whole-body metabolic rate, body temperature, wet thermal conductance, evaporative water loss, and relative water economy of chicks at three ages corresponding to ectothermic (day 5), poikilothermic (day 12), and homoeothermic (day 50) stages. Additionally, we measured mitochondrial bioenergetics of blood cells 80 days post-hatch. While early-life exposure to heat wave conditions did not impact whole body metabolic and hygric physiology, body temperature was lower for birds from heated compared with control nests at both 12 and 50 days of age. There was also an effect of nest heating at the cellular level, with mitochondria from heated birds having higher endogenous and proton-leak related respiration, although oxidative phosphorylation, maximum respiratory capacity, and coupling efficiency were not impacted. Our results suggest that early-life exposure to high ambient temperature induces programming effects on cellular-level and thermal physiology that may not be apparent for whole-animal metabolism.

17.
Telemed J E Health ; 27(10): 1166-1173, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33395364

RESUMO

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.


Assuntos
COVID-19 , Telemedicina , Estudos de Viabilidade , Humanos , Recém-Nascido , Pandemias , SARS-CoV-2
18.
Brain Imaging Behav ; 15(4): 2121-2125, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33044730

RESUMO

Performance in verbal fluency tasks are widely used as a marker of cognitive impairment in Parkinson disease. However, the anatomical substrate of its impairment remains undetermined. Based on the dual-stream language model, we hypothesized cortical input to the subcortical circuitry would be a crucial determinant of fluency. We performed a retrospective study using individual whole-brain structural connectomes derived from 135 individuals with PD and assessed the relationship between white matter integrity and verbal fluency tasks. Controlling for multiple factors, including dysarthria, we observed higher integrity of dorsal stream-caudate connectivity was associated with better letter fluency. This preliminary study indicates the possible dissociation between dorsal and ventral stream connectivity and letter fluency in PD. In addition, it suggests a non-motor role of the frontostriatal fibers in letter fluency.


Assuntos
Doença de Parkinson , Humanos , Idioma , Imageamento por Ressonância Magnética , Testes Neuropsicológicos , Doença de Parkinson/diagnóstico por imagem , Estudos Retrospectivos
19.
J Exp Biol ; 223(Pt 23)2020 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-33097571

RESUMO

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.


Assuntos
Marsupiais , Animais , Regulação da Temperatura Corporal , Temperatura Alta , Umidade , Água , Perda Insensível de Água
20.
J Exp Biol ; 223(Pt 19)2020 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-32747451

RESUMO

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.


Assuntos
Papagaios , Perda Insensível de Água , Animais , Regulação da Temperatura Corporal , Temperatura , Água
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