Unlabelled: Remains of megatheres have been known since the 18th -century and were among the first megafaunal vertebrates to be studied. While several examples of preserved integument show a thick coverage of fur for smaller ground sloths living in cold climates such as and , comparatively very little is known about megathere skin. Assuming a typical placental mammal metabolism, it was previously hypothesized that megatheres would have had little-to-no fur as they achieved giant body sizes.
View Article and Find Full Text PDFAs opportunistic generalists occupying a range of ecological niches, chacma baboons (Papio ursinus) are considered a highly flexible species of relatively low conservation priority. Underlying their ecological flexibility is a repertoire of behavioral strategies observed in response to ecological stressors. Although these strategies are relatively well-documented, we know very little about how they impact upon an individual's thermal and energetic physiology, which can influence population-level reproductive potential in the face of climatic warming.
View Article and Find Full Text PDFThe effects of climate change on animals are typically viewed in terms of survivability and wellbeing. In this study, we broaden that purview to include climate impacts on reproductive capability. There are not only climate spaces for daily function, but climate cliffs that represent reproductive failures in the face of climate warming.
View Article and Find Full Text PDFUnderstanding where and why organisms are experiencing thermal and hydric stress is critical for predicting species' responses to climate change. Biophysical models that explicitly link organismal functional traits like morphology, physiology, and behavior to environmental conditions can provide valuable insight into determinants of thermal and hydric stress. Here we use a combination of direct measurements, 3D modeling, and computational fluid dynamics to develop a detailed biophysical model of the sand fiddler crab, Leptuca pugilator.
View Article and Find Full Text PDFPlast Reconstr Surg
January 2024
Background: The Whitnall barrier procedure, a modified Beer and Kompatscher surgical technique to reposition the lacrimal gland, is presented alongside a case series of patients demonstrating excellent aesthetic and functional outcomes.
Methods: The Whitnall barrier procedure is illustrated procedurally and accompanied by a case series of 20 consecutive patients treated in a single institution by a single surgical team between December of 2016 and February of 2020. Lid contour and function were assessed postoperatively, as was patient satisfaction.
Climate warming creates energetic challenges for endothermic species by increasing metabolic and hydric costs of thermoregulation. Although endotherms can invoke an array of behavioural and physiological strategies for maintaining homeostasis, the relative effectiveness of those strategies in a climate that is becoming both warmer and drier is not well understood. In accordance with the heat dissipation limit theory which suggests that allocation of energy to growth and reproduction by endotherms is constrained by the ability to dissipate heat, we expected that patterns of habitat use by large, heat-sensitive mammals across multiple scales are critical for behavioural thermoregulation during periods of potential heat stress and that they must invest a large portion of time to maintain heat balance.
View Article and Find Full Text PDFA core challenge in global change biology is to predict how species will respond to future environmental change and to manage these responses. To make such predictions and management actions robust to novel futures, we need to accurately characterize how organisms experience their environments and the biological mechanisms by which they respond. All organisms are thermodynamically connected to their environments through the exchange of heat and water at fine spatial and temporal scales and this exchange can be captured with biophysical models.
View Article and Find Full Text PDFPolitical, economic, and climatic upheaval can result in mass human migration across extreme terrain in search of more humane living conditions, exposing migrants to environments that challenge human tolerance. An empirical understanding of the biological stresses associated with these migrations will play a key role in the development of social, political, and medical strategies for alleviating adverse effects and risk of death. We model physiological stress associated with undocumented migration across a commonly traversed section of the southern border of the United States and find that locations of migrant death are disproportionately clustered within regions of greatest predicted physiological stress (evaporative water loss).
View Article and Find Full Text PDFEach winter, the North Atlantic Ocean is the stage for numerous cyclones, the most severe ones leading to seabird mass-mortality events called "winter wrecks." During these, thousands of emaciated seabird carcasses are washed ashore along European and North American coasts. Winter cyclones can therefore shape seabird population dynamics by affecting survival rates as well as the body condition of surviving individuals and thus their future reproduction.
View Article and Find Full Text PDFWe explored the implications of reaching the Paris Agreement Objective of limiting global warming to <2°C for the future winter distribution of the North Atlantic seabird community. We predicted and quantified current and future winter habitats of five North Atlantic Ocean seabird species (Alle alle, Fratercula arctica, Uria aalge, Uria lomvia and Rissa tridactyla) using tracking data for ~1500 individuals through resource selection functions based on mechanistic modeling of seabird energy requirements, and a dynamic bioclimate envelope model of seabird prey. Future winter distributions were predicted to shift with climate change, especially when global warming exceed 2°C under a "no mitigation" scenario, modifying seabird wintering hotspots in the North Atlantic Ocean.
View Article and Find Full Text PDFIn the face of climate change there is an urgent need to understand how animal performance is affected by environmental conditions. Biophysical models that use principles of heat and mass transfer can be used to explore how an animal's morphology, physiology, and behavior interact with its environment in terms of energy, mass and water balances to affect fitness and performance. We used Niche Mapper™ (NM) to build a vervet monkey (Chlorocebus pygerythrus) biophysical model and tested the model's ability to predict core body temperature (T) variation and thermal stress against T and behavioral data collected from wild vervets in South Africa.
View Article and Find Full Text PDFNitrate contamination of drinking water, common in agricultural areas, increases the risk of certain cancers and impacts fetal development during pregnancy. Building on previously published methodology, this study evaluates nitrate-attributable disease cases and adverse birth outcomes as well as their economic costs for Wisconsin, USA. Nitrate is the most common contaminant in groundwater in Wisconsin.
View Article and Find Full Text PDFToxic effects of heavy oiling to wildlife are well known from oil spills, although sublethal oil exposure effects are poorly understood. We used Niche Mapper™, to compute spatially and temporally specific energetic and behavioral impacts of repeated sublethal oil exposure to double-crested cormorants (Phalacrocorax auritus). During winter (October-March) cormorants exposed to 13 g, 39 g, and 65-78 g of oil, had on average a 31%, 59%, and 76% predicted increase in total resting energetic requirements (RMR) compared to unoiled birds, respectively.
View Article and Find Full Text PDFWe employed the widely-tested biophysiological modeling software, Niche Mapper™ to investigate the metabolic function of the Late Triassic dinosaurs Plateosaurus and Coelophysis during global greenhouse conditions. We tested a variety of assumptions about resting metabolic rate, each evaluated within six microclimate models that bound paleoenvironmental conditions at 12° N paleolatitude, as determined by sedimentological and isotopic proxies for climate within the Chinle Formation of the southwestern United States. Sensitivity testing of metabolic variables and simulated "metabolic chamber" analyses support elevated "ratite-like" metabolic rates and intermediate "monotreme-like" core temperature ranges in these species of early saurischian dinosaur.
View Article and Find Full Text PDFClimate models predict that by 2050 the Arctic Ocean will be sea ice free each summer. Removing this barrier between the Atlantic and the Pacific will modify a wide range of ecological processes, including bird migration. Using published information, we identified 29 arctic-breeding seabird species, which currently migrate in the North Atlantic and could shift to a transarctic migration towards the North Pacific.
View Article and Find Full Text PDFPurpose: Extrusion is the most common cause of failure in conventional Lester Jones tubes (LJTs). StopLoss Jones tubes (SLJTs) with distal flange are designed to reduce this complication. This study compared the survival of SLJTs with their prior LJTs and control patients with LJTs-only.
View Article and Find Full Text PDFObjectives: To illustrate the varying clinical presentations of cutaneous sarcoidosis affecting the periocular region, which may masquerade as other clinical entities such as basal cell carcinoma or seborrheic dermatitis. Furthermore, the authors present an unusual observation of lupus pernio involving the adnexal region with the rare presence of perineural granulomas on histology following incisional biopsy.
Methods: We report a consecutive series of four cases with lesions involving the eyelids with varying clinical appearances.
Polycyclic aromatic hydrocarbons (PAHs) continue to be common environmental contaminants. The anthropogenic sources of these compounds are broadly classed as petrogenic and pyrogenic, but more importantly specific sources including activities such as coal burning, oil spills, and application of coal tar sealants can be identified based on several types of data analysis. Several studies have focused on PAHs in sediments of lakes, streams, and stormwater ponds in larger urban areas, finding contamination arising from a number of different sources and correlating well to land use in the nearby watershed.
View Article and Find Full Text PDFOn St. Paul Island, a remnant of the Bering Land Bridge, woolly mammoths persisted until 5,600 yr BP with no known predators or competitors, providing a natural system for studying hypothesized environmental drivers of extinction. These include overheating due to rising temperatures, starvation, and drought.
View Article and Find Full Text PDFTo fully understand the impact of oil exposure, it is important to understand sublethal effects like how increased thermoregulatory costs may affect survival and reproduction. However, it is difficult and time-consuming to measure these effects in wild animals. We present a novel use of a bioenergetics model, Niche Mapper™, to estimate thermoregulatory impacts of oiling, using data from captive Double-crested Cormorants (Phalacrocorax auritus) experimentally exposed to oil.
View Article and Find Full Text PDFThere is an urgent need for a better understanding of animal migratory ecology under the influence of climate change. Most current analyses require long-term monitoring of populations on the move, and shorter-term approaches are needed. Here, we analysed the ecological drivers of seabird migration within the framework of the energyscape concept, which we defined as the variations in the energy requirements of an organism across geographical space as a function of environmental conditions.
View Article and Find Full Text PDFThreatened and endangered species are more vulnerable to climate change due to small population and specific geographical distribution. Therefore, identifying and incorporating the biological processes underlying a species' adaptation to its environment are important for determining whether they can persist in situ. Correlative models are widely used to predict species' distribution changes, but generally fail to capture the buffering capacity of organisms.
View Article and Find Full Text PDFMolybdenum (Mo) is an essential trace nutrient but has negative health effects at high concentrations. Groundwater typically has low Mo (<2 μg/L), and elevated levels are associated with anthropogenic contamination, although geogenic sources have also been reported. Coal combustion residues (CCRs) are enriched in Mo, and thus present a potential anthropogenic contamination source.
View Article and Find Full Text PDFPurposeExtraocular muscle enlargement (EOME) is most commonly associated with thyroid eye disease, but there are other causes. We report our outcomes of investigating and managing non-thyroid-related EOME (NTR-EOME).MethodsRetrospective consecutive case series.
View Article and Find Full Text PDFPurpose: Unifying terminology for the description of ocular surface disease (OSD) is vital for determining treatment responses and ensuring robust clinical trial outcomes. To date, there are no agreed parameters describing 'activity' and 'damage' phases of disease.
Methods: A working group of international experts in OSD, oculoplastics, and uveitis from a range of backgrounds (university, teaching, district general and private hospitals) participated in a modified Delphi consensus-building exercise (October 31, 2011 to March 20, 2015).