Adipose tissue estimation of foraging and nesting green turtles Chelonia mydas using bioelectrical impedance analysis

Adipose tissue is the main energy store in sea turtles and fluctuates in response to dietary conditions and external stressors. Monitoring programmes commonly use body condition indices (BCIs) to infer the nutritional and health status of sea turtle populations. However, BCIs have poor predictive power for estimating adipose tissue. We introduce the use of bioelectrical impedance analysis (BIA) as a portable technique to estimate adipose tissue in green turtles Chelonia mydas. The aims of this study were to estimate adipose tissue of green turtles on the Great Barrier Reef (Australia), and to examine whether adipose tissue is a more sensitive indicator than BCI. Turtles (n = 250) were sampled at 3 foraging sites and at a nesting beach with differing levels of anthropogenic impact. Differences in adipose tissue, Fulton’s BCI, and body mass across study sites and life stages were assessed by conducting linear mixed effects models. BIA estimates of mean adipose tissue revealed significant differences across life stages and sampling sites, that were not found using BCI data. Mean adipose tissue was estimated to be 4.6 ± 0.6% (% body mass ± SD) and was not correlated with mean BCI (1.2 ± 0.1). Adipose tissue was not reduced in turtles foraging at sites with a high level of anthropogenic impact. Adult turtles had significantly higher adipose tissue values than juveniles and subadults. Adult females measured during and shortly before nesting season had the highest adipose tissue values (%). BIA is a practical method for estimating adipose tissue, and we recommend this technique for consideration in sea turtle monitoring programmes

Murine thymic NK cells are distinct from ILC1s and have unique transcription factor requirements

open7sìGroup 1 innate lymphoid cells include natural killer (NK) cells and ILC1s, which mediate the response to intracellular pathogens. Thymic NK (tNK) cells were described with hybrid features of immature NK cells and ILC1 but whether these cells are related to NK cells or ILC1 has not been fully investigated. We report that murine tNK cells expressed the NK-cell associated transcription factor EOMES and developed independent of the essential ILC1 factor TBET, confirming their placement within the NK lineage. Moreover, tNK cells resemble NK cells rather than ILC1 in their requirements for the E protein transcription factor inhibitor ID2. We provide further insight into the mechanisms governing tNK-cell development by showing that the transcription factor ETS1 prevented tNK cell acquisition of the conventional NK-cell maturation markers CD11b and KLRG1. Our data reveal few ILC1 in the thymus and clarify the identity and developmental requirements of tNK cells. This article is protected by copyright. All rights reserved.openGabrielli, Sara; Sun, Mengxi; Bell, April; Zook, Erin C; de Pooter, Renee F; Zamai, Loris; Kee, Barbara LGabrielli, Sara; Sun, Mengxi; Bell, April; Zook, Erin C; de Pooter, Renee F; Zamai, Loris; Kee, Barbara L

The Progenitors of the Compact Early-Type Galaxies at High-Redshift

We use GOODS and CANDELS images to identify progenitors of massive (log M > 10 Msun) compact "early-type" galaxies (ETGs) at z~1.6. Since merging and accretion increase the size of the stellar component of galaxies, if the progenitors are among known star-forming galaxies, these must be compact themselves. We select candidate progenitors among compact Lyman-break galaxies at z~3 based on their mass, SFR and central stellar density and find that these account for a large fraction of, and possibly all, compact ETGs at z~1.6. We find that the average far-UV SED of the candidates is redder than that of the non-candidates, but the optical and mid-IR SED are the same, implying that the redder UV of the candidates is inconsistent with larger dust obscuration, and consistent with more evolved (aging) star-formation. This is in line with other evidence that compactness is a sensitive predictor of passivity among high-redshift massive galaxies. We also find that the light distribution of both the compact ETGs and their candidate progenitors does not show any extended "halos" surrounding the compact "core", both in individual images and in stacks. We argue that this is generally inconsistent with the morphology of merger remnants, even if gas-rich, as predicted by N-body simulations. This suggests that the compact ETGs formed via highly dissipative, mostly gaseous accretion of units whose stellar components are very small and undetected in the HST images, with their stellar mass assembling in-situ, and that they have not experienced any major merging until the epoch of observations at z~1.6.Comment: 25 pages, 20 figures; Accepted for publication in Ap

Field‐based adipose tissue quantification in sea turtles using bioelectrical impedance spectroscopy validated with CT scans and deep learning

Loss of adipose tissue in vertebrate wildlife species is indicative of decreased nutritional and health status and is linked to environmental stress and diseases. Body condition indices (BCI) are commonly used in ecological studies to estimate adipose tissue mass across wildlife populations. However, these indices have poor predictive power, which poses the need for quantitative methods for improved population assessments. Here, we calibrate bioelectrical impedance spectroscopy (BIS) as an alternative approach for assessing the nutritional status of vertebrate wildlife in ecological studies. BIS is a portable technology that can estimate body composition from measurements of body impedance and is widely used in humans. BIS is a predictive technique that requires calibration using a reference body composition method. Using sea turtles as model organisms, we propose a calibration protocol using computed tomography (CT) scans, with the prediction equation being: adipose tissue mass (kg) = body mass − (−0.03 [intercept] − 0.29 * length2/resistance at 50 kHz + 1.07 * body mass − 0.11 * time after capture). CT imaging allows for the quantification of body fat. However, processing the images manually is prohibitive due to the extensive time requirement. Using a form of artificial intelligence (AI), we trained a computer model to identify and quantify nonadipose tissue from the CT images, and adipose tissue was determined by the difference in body mass. This process enabled estimating adipose tissue mass from bioelectrical impedance measurements. The predictive performance of the model was built on 2/3 samples and tested against 1/3 samples. Prediction of adipose tissue percentage had greater accuracy when including impedance parameters (mean bias = 0.11%–0.61%) as predictor variables, compared with using body mass alone (mean bias = 6.35%). Our standardized BIS protocol improves on conventional body composition assessment methods (e.g., BCI) by quantifying adipose tissue mass. The protocol can be applied to other species for the validation of BIS and to provide robust information on the nutritional and health status of wildlife, which, in turn, can be used to inform conservation decisions at the management level

Using Indium-111 labeled radiopharmaceuticals to target the BB2 receptor on human prostate cancer cells [abstract]

Abstract only availableThe BB2 receptor, belonging to the Bombesin receptor family, has been shown to be highly over expressed in a variety of cancer cell lines, including human prostate cancer. Our laboratory have been involved, for over a decade, in synthesizing Bombesin analogues that target the BB2 receptor for the purpose of developing radiopharmaceuticals for diagnostic and/or therapeutic treatment of cancer. Radiopharmaceuticals based on Bombesin are typically composed of a chelator, isotope, linking group and targeting vector [See Bifunctional Conjugate Design [figure below]. Previous studies by our group and others have shown that variations in linking groups affect the retention time of the bifunctional conjugate in prostate cancer (PC-3) cells. Higher retention time allows for more efficacious therapeutic benefits and enhanced diagnostic imaging capabilities. In this study, we seek to determine the pharmacokinetic benefits achieved in altering the linking group using aliphatic and aromatic linking groups. In-vitro analysis of the radiopharmaceuticals studied found that the Bombesin derivative with the aliphatic linking group demonstrated a slightly higher affinity for the BB2 receptor compared to the Bombesin analogs containing aromatic linking groups. In vivo pharmacokinetic and imaging studies were performed using pre-clinical models of prostate cancer. The tumor uptake of the Bombesin derivatives with the aromatic linking groups were found to be significantly higher compared to that of the Bombesin derivative with the aliphatic linking group. In contrast, the aromatic Bombesin analogs also exhibited higher amounts of undesirable accumulation in the kidneys and other non-target tissues. In conclusion, we found that the aliphatic compounds were more appropriate for diagnostic imaging of prostate cancer due to the reduced non-target retention. The Bombesin analogs with aromatic linking groups showed potential for use as therapeutic agents for prostate cancer treatment.National Institutes of Health Molecular Imaging Progra

Targeting the BB2 receptor on human prostate cancer cells using Indium-111 labeled radiopharmaceutical [abstract]

Abstract only availableFaculty Mentor: Dr. Timothy Hoffman, Internal MedicineThe BB2 receptor, belonging to the Bombesin receptor family, has been shown to be highly over expressed in a variety of cancer cell lines, including human prostate cancer. Over expression of the BB2 receptor offers an appealing target for the design of targeted radiopharmaceuticals.  The Hoffman laboratory and others have been involved, for over a decade, in synthesizing Bombesin analogues that target the BB2 receptor for the purpose of developing a viable radiopharmaceutical for diagnostic or therapeutic treatment of cancer. Radiopharmaceuticals based on Bombesin analogues are typically composed of a targeting vector, radioisotope, chelator and linking group [See Bifunctional Conjugate Design figure below]. Previous studies have shown that variations in linking groups may affect the retention time of the bifunctional conjugate in prostate cancer (PC-3) cells.  Higher retention time allows for more efficacious therapeutic benefits and enhanced diagnostic imaging capabilities.  In the work presented, we designed and synthesized a 111In-Bombesin analogue with a phenyl linker group in order to determine if the phenyl linker group would provide higher retention times in prostate cancer.  In-vitro analysis of the radiopharmaceutical was performed using PC-3 cells to determine the affinity of the new compound for the BB2 receptor to be 1.09 nM. In-vivo studies of the radiopharmaceutical were also conducted by injection of the radiopharmaceutical into CF-1 (“normal”) mice, as well as SCID (Severe Combined Immunodeficient) mice bearing 2-3 week old PC-3 tumors. Experimental results on SCID mice revealed uptakes of 6.36, 3.34, 2.42 and 1.69 % Injected Dose of radiopharmaceutical per gram of tumor tissue at 0.25, 1, 4 and 24 hours, respectively. Imaging using Micro-SPECT (Single-Photon Emission Computed Tomography) was performed to track the dispersion of the radiopharmaceutical throughout the mouse model and confirmed the targeted uptake of the radiopharmaceutical

Life history linked to immune investment in developing amphibians

The broad diversity of amphibian developmental strategies has been shaped, in part, by pathogen pressure, yet trade-offs between the rate of larval development and immune investment remain poorly understood. The expression of antimicrobial peptides (AMPs) in skin secretions is a crucial defense against emerging amphibian pathogens and can also indirectly affect host defense by influencing the composition of skin microbiota. We examined the constitutive or induced expression of AMPs in 17 species at multiple life-history stages. We found that AMP defenses in tadpoles of species with short larval periods (fast pace of life) were reduced in comparison with species that overwinter as tadpoles and grow to a large size. A complete set of defensive peptides emerged soon after metamorphosis. These findings support the hypothesis that species with a slow pace of life invest energy in AMP production to resist potential pathogens encountered during the long larval period, whereas species with a fast pace of life trade this investment in defense for more rapid growth and development

The price of your soul: neural evidence for the non-utilitarian representation of sacred values

Sacred values, such as those associated with religious or ethnic identity, underlie many important individual and group decisions in life, and individuals typically resist attempts to trade off their sacred values in exchange for material benefits. Deontological theory suggests that sacred values are processed based on rights and wrongs irrespective of outcomes, while utilitarian theory suggests that they are processed based on costs and benefits of potential outcomes, but which mode of processing an individual naturally uses is unknown. The study of decisions over sacred values is difficult because outcomes cannot typically be realized in a laboratory, and hence little is known about the neural representation and processing of sacred values. We used an experimental paradigm that used integrity as a proxy for sacredness and which paid real money to induce individuals to sell their personal values. Using functional magnetic resonance imaging (fMRI), we found that values that people refused to sell (sacred values) were associated with increased activity in the left temporoparietal junction and ventrolateral prefrontal cortex, regions previously associated with semantic rule retrieval. This suggests that sacred values affect behaviour through the retrieval and processing of deontic rules and not through a utilitarian evaluation of costs and benefits

Genomic signatures in the coral holobiont reveal host adaptations driven by Holocene climate change and reef specific symbionts

Genetic signatures caused by demographic and adaptive processes during past climatic shifts can inform predictions of species’ responses to anthropogenic climate change. To identify these signatures in Acropora tenuis, a reef-building coral threatened by global warming, we first assembled the genome from long reads and then used shallow whole-genome resequencing of 150 colonies from the central inshore Great Barrier Reef to inform population genomic analyses. We identify population structure in the host that reflects a Pleistocene split, whereas photosymbiont differences between reefs most likely reflect contemporary (Holocene) conditions. Signatures of selection in the host were associated with genes linked to diverse processes including osmotic regulation, skeletal development, and the establishment and maintenance of symbiosis. Our results suggest that adaptation to post-glacial climate change in A. tenuis has involved selection on many genes, while differences in symbiont specificity between reefs appear to be unrelated to host population structure