Migration Distance and Sexual Dichromatism: Cost of Migration is Correlated with Reduced Female Coloration in Wood Warblers

Avian sexual dichromatism has been observed to be greater at higher latitudes, and one of the long-standing explanations for the underlying evolutionary forces underlying this geographic pattern is the breeding latitude hypothesis, which focuses on changes in male ornamentation and posits that sexual selection for male ornamentation is stronger at higher latitudes. I offer an alterative hypothesis that focuses on how changes in female coloration can drive the evolution of sexual dichromatism. I propose that the costs of migration, including increased predation risk and high energetic costs, negatively select against elaborate plumage coloration, and that the distance a species migrates is positively related to these costs. Furthermore, because positive directional selection for ornamentation is generally greater on males than on females, I propose that the costs associated with longer migration have imposed stronger net negative selection on female ornamentation compared to male ornamentation. Specifically, I predict that migration distance is positively related to sexual dichromatism. To address both the breeding latitude and migration distance hypotheses, I tested how migration distance and breeding latitude predict sexual differences in plumage coloration among wood warblers (Parulidae) using independent contrasts to control for phylogeny. Both migration distance and breeding latitude independently predict sexual dichromatism, and based on model-selection analyses, my results indicate that migration distance has more predictive power than breeding latitude. Thus, these results provide evidence consistent with the mechanism that changes in female ornamentation have driven the evolution of sexual dichromatism. Furthermore, these results suggest that incremental increases in migration distances are associated with concurrent increases in the costs associated with ornamentation. Future studies of both migratory and non-migratory taxa should consider how costs associated with female ornamentation might contribute to the evolution of sexual dimorphism

Towards Optimal Patch Size in Vision Transformers for Tumor Segmentation

Detection of tumors in metastatic colorectal cancer (mCRC) plays an essential role in the early diagnosis and treatment of liver cancer. Deep learning models backboned by fully convolutional neural networks (FCNNs) have become the dominant model for segmenting 3D computerized tomography (CT) scans. However, since their convolution layers suffer from limited kernel size, they are not able to capture long-range dependencies and global context. To tackle this restriction, vision transformers have been introduced to solve FCNN's locality of receptive fields. Although transformers can capture long-range features, their segmentation performance decreases with various tumor sizes due to the model sensitivity to the input patch size. While finding an optimal patch size improves the performance of vision transformer-based models on segmentation tasks, it is a time-consuming and challenging procedure. This paper proposes a technique to select the vision transformer's optimal input multi-resolution image patch size based on the average volume size of metastasis lesions. We further validated our suggested framework using a transfer-learning technique, demonstrating that the highest Dice similarity coefficient (DSC) performance was obtained by pre-training on training data with a larger tumour volume using the suggested ideal patch size and then training with a smaller one. We experimentally evaluate this idea through pre-training our model on a multi-resolution public dataset. Our model showed consistent and improved results when applied to our private multi-resolution mCRC dataset with a smaller average tumor volume. This study lays the groundwork for optimizing semantic segmentation of small objects using vision transformers. The implementation source code is available at:https://github.com/Ramtin-Mojtahedi/OVTPS

No impact of CMV or EBV seropositivity on the frequency of highly differentiated T-cells in Mexican-American adolescents

Recurring activations of the prevalent latent herpes viruses Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) induces immune cell division leading to the premature terminal differentiation of T-cells. Terminally differentiated T-cells are known to accumulate with age causing a reduction in the naïve T-cell repertoire, which compromises the ability of the adaptive immune system to respond to novel pathogens. Although CMV and EBV seropositivity are hallmarks of the “immune risk profile” and are known to influence the frequency of terminally differentiated T-cells and increase infection risk in adults, it is not known if CMV or EBV impacts on the frequency of these cells in a young subject cohort. PURPOSE: To examine the impact of CMV and EBV seropositivity on the frequency of highly differentiated blood T-cells in Mexican-American adolescents. METHODS: Fasted resting blood samples were obtained from 77 adolescents consisting of both males and females. The presence of antibodies against CMV and EBV was determined in serum by ELISA. Lymphocytes isolated from peripheral blood were assessed for a combination of cell surface markers to determine their stage of differentiation. Monoclonal antibodies and four-color flow cytometry were used to identify senescent (CD27-, CD28-, CD57+), naïve (CCR7+, CD45RA+), memory (CCR7-, CD45RA-) and effector memory (CCD7-, CD45RA+) T-cell markers on pan CD3+ T-cells, CD4+ T-cells and CD8+ T-cells. Differences in T-cell phenotype between the CMV/EBV seropositive and seronegative participants were compared using independent Student t-tests. RESULTS: The prevalence of latent CMV and EBV infection among the subject cohort was 16% and 44% respectively, while 7% of all participants were carrying a latent infection for both. No differences in senescent and memory phenotypes were found between the CMV or EBV seropositive and seronegative groups. CONCLUSION: Despite the known influence of latent CMV and EBV infection on the frequency of senescent T-cells in adults, these preliminary data indicate that CMV and EBV seropositivity has no impact on the frequency of senescent T-cells in adolescents. These data suggest that the increased frequency of terminally differentiated T-cells that are associated with CMV and EBV seropositivity in adults is probably due to long-term infections. Future studies will assess the impact of CMV and EBV seropositivity on immunosenescence in association with other factors known to have an effect on T-cells differentiation, such as BMI and physical activity status

Longitudinal, Diet-induced Weight Gain is Associated with Increased Blood Monocytes and Reduced TLR4 Expression

Excessive weight gain increases systemic inflammation resulting in increased disease risk. Toll-like receptor 4 (TLR4) reportedly mediates increases in inflammation; however, its role has not been fully evaluated. Objective. The purpose of this study was to determine the longitudinal effect of diet-induced weight gain on blood monocyte concentration and cell-surface TLR4 expression. Research Methods & Procedures. Male CD-1 mice were randomly assigned to high-fat (HF, n = 12) or low-fat (LF, n = 13) groups. Non-lethal, saphenous vein blood samples were collected at 0, 4, 8 and 12 weeks of treatment. Three-color flow cytometry was used to measure monocyte (CD11b+/CD14+) concentration and TLR4 cells-surface expression. Data were analyzed with a repeated measures ANOVA; significance was set at P\u3c0.05. Results. Body weight at week 12 was 21% greater in HF than LF (P\u3c0.05). At week 12 HF had 155% more monocytes (P\u3c0.05) with 24% less TLR4; Monocyte concentration and body weight at week 12 was negatively correlated with TLR4 gMFI (P\u3c0.05). Conclusions. The observed effects of high-fat feeding on blood monocytes are consistent with a phenotype, which may be associated with premature morbidity. The observed monocyte responses may be associated with immune dysfunction and diminished response to infection

Aerobic Exercise Training May Not Offset the Pro-inflammatory Effects of a High Fat Feeding

Aerobic Exercise Training May Not Offset the Pro-inflammatory Effects of a High Fat Feeding. Katie C. Carpenter, Lisa Esposito, Kelley A. Strohacker, Richard J. Simpson, Brian K. McFarlin. University of Houston, Houston, TX Increased adiposity is associated with an increase in systemic inflammation, which is involved in the pathophysiology of various disease states. A current hypothesis in our laboratory suggests that the toll-like receptor 4 (TLR4) pathway may link physical activity and systemic inflammation. PURPOSE: The primary purpose was to determine if 6-weeks of aerobic exercise training (5 days per week, 1 hour per day. 21-22m/min) would limit the increase in systemic inflammation resulting from high-fat (60% of calories from fat) feeding. A secondary purpose was to determine if changes in cell-surface TLR4 expression would account for observed differences in inflammatory status between mice which exercise and those that remain sedentary. METHODS: 36 CD-1 male mice were randomly assigned to one of three groups (N=12/group): HF (remained sedentary and consumed a high-fat chow (60% fat)), HF-EX (consumed the high-fat chow and underwent an aerobic exercise intervention (running 4.56±0.08 h/week for 6 weeks, or LF (sedentary and consumed a low-fat chow (10% fat)). Key outcome measurements were made on weekly saphenous vein blood samples (~40 uL) using 3-color flow cytometry. Blood glucose and cholesterol concentration were analyzed by an enzymatic assay. RESULTS: Absolute and percent body weight gain over 6-weeks was similar between HF and HF-EX, but significantly greater than LF (P\u3c0.001). HF and HF-EX had 66% more leukocytes than LF at weeks 3-5 (P\u3c0.0001). HF and HF-EX had 145% greater CD11b+/14+/TLR4+ cells than LF (P=0.001). There was no difference in the concentration of CD11b+ cells expressing IL-6 or TNF-alpha following LPS-stimulation between HF and HF-EX. No significant difference was found for blood glucose and cholesterol concentrations between groups. CONCLUSIONS: Exercise training did not prevent weight gain during 6-weeks of high fat feeding. Since HF and HF+EX gained a similar amount of weight, they did not differ with regarding to blood monocytes expressing TLR4. Both HF and HF+EX were elevated above LF. More research is needed to determine how changes in the blood relate to changes in peripheral tissue compartments

Evolutionary innovation and diversification of carotenoid-based pigmentation in finches

© 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution. The ornaments used by animals to mediate social interactions are diverse, and by reconstructing their evolutionary pathways we can gain new insights into the mechanisms underlying ornamental innovation and variability. Here, we examine variation in plumage carotenoids among the true finches (Aves: Fringillidae) using biochemical and comparative phylogenetic analyses to reconstruct the evolutionary history of carotenoid states and evaluate competing models of carotenoid evolution. Our comparative analyses reveal that the most likely ancestor of finches used dietary carotenoids as yellow plumage colorants, and that the ability to metabolically modify dietary carotenoids into more complex pigments arose secondarily once finches began to use modified carotenoids to create red plumage. Following the evolutionary “innovation” that enabled modified red carotenoid pigments to be deposited as plumage colorants, many finch species subsequently modified carotenoid biochemical pathways to create yellow plumage. However, no reversions to dietary carotenoids were observed. The finding that ornaments and their underlying mechanisms may be operating under different selection regimes—where ornamental trait colors undergo frequent reversions (e.g., between red and yellow plumage) while carotenoid metabolization mechanisms are more conserved—supports a growing empirical framework suggesting different evolutionary patterns for ornaments and the mechanistic innovations that facilitate their diversification

Critical success index or F measure to validate the accuracy of administrative healthcare data identifying epilepsy in deceased adults in Scotland

Background: Methods to undertake diagnostic accuracy studies of administrative epilepsy data are challenged bylack of a way to reliably rank case-ascertainment algorithms in order of their accuracy. This is because it isdifficult to know how to prioritise positive predictive value (PPV) and sensitivity (Sens). Large numbers of truenegative (TN) instances frequently found in epilepsy studies make it difficult to discriminate algorithm accuracyon the basis of negative predictive value (NPV) and specificity (Spec) as these become inflated (usually >90%).This study demonstrates the complementary value of using weather forecasting or machine learning metricscritical success index (CSI) or F measure, respectively, as unitary metrics combining PPV and sensitivity. Wereanalyse data published in a diagnostic accuracy study of administrative epilepsy mortality data in Scotland.Method: CSI was calculated as 1/[(1/PPV) + (1/Sens) – 1]. F measure was calculated as 2.PPV.Sens/(PPV +Sens). CSI and F values range from 0 to 1, interpreted as 0 = inaccurate prediction and 1 = perfect accuracy. Thepublished algorithms were reanalysed using these and their accuracy re-ranked according to CSI in order to allowcomparison to the original rankings.Results: CSI scores were conservative (range 0.02–0.826), always less than or equal to the lower of the correspondingPPV (range 39–100%) and sensitivity (range 2–93%). F values were less conservative (range0.039–0.905), sometimes higher than either PPV or sensitivity, but were always higher than CSI. Low CSI and Fvalues occurred when there was a large difference between PPV and sensitivity, e.g. CSI was 0.02 and F was0.039 in an instance when PPV was 100% and sensitivity was 2%. Algorithms with both high PPV and sensitivityperformed best in terms of CSI and F measure, e.g. CSI was 0.826 and F was 0.905 in an instance when PPV was90% and sensitivity was 91%.Conclusion: CSI or F measure can combine PPV and sensitivity values into a convenient single metric that is easierto interpret and rank in terms of diagnostic accuracy than trying to rank diagnostic accuracy according to the twomeasures themselves. CSI or F prioritise instances where both PPV and sensitivity are high over instances wherethere are large differences between PPV and sensitivity (even if one of these is very high), allowing diagnosticaccuracy thresholds based on combined PPV and sensitivity to be determined. Therefore, CSI or F measures maybe helpful complementary metrics to report alongside PPV and sensitivity in diagnostic accuracy studies ofadministrative epilepsy data