6 research outputs found
Exorcising Grice’s ghost : an empirical approach to studying intentional communication in animals
Language’s intentional nature has been highlighted as a crucial feature distinguishing it from other communication systems. Specifically, language is often thought to depend on highly structured intentional action and mutual mindreading by a communicator and recipient. Whilst similar abilities in animals can shed light on the evolution of intentionality, they remain challenging to detect unambiguously. We revisit animal intentional communication and suggest that progress in identifying analogous capacities has been complicated by (i) the assumption that intentional (that is, voluntary) production of communicative acts requires mental-state attribution, and (ii) variation in approaches investigating communication across sensory modalities. To move forward, we argue that a framework fusing research across modalities and species is required. We structure intentional communication into a series of requirements, each of which can be operationalised, investigated empirically, and must be met for purposive, intentionally communicative acts to be demonstrated. Our unified approach helps elucidate the distribution of animal intentional communication and subsequently serves to clarify what is meant by attributions of intentional communication in animals and humans
Integration of clinical parameters and CT-based radiomics improves machine learning assisted subtyping of primary hyperaldosteronism
ObjectivesThe aim of this study was to investigate an integrated diagnostics approach for prediction of the source of aldosterone overproduction in primary hyperaldosteronism (PA).Methods269 patients from the prospective German Conn Registry with PA were included in this study. After segmentation of adrenal glands in native CT images, radiomic features were calculated. The study population consisted of a training (n = 215) and a validation (n = 54) cohort. The k = 25 best radiomic features, selected using maximum-relevance minimum-redundancy (MRMR) feature selection, were used to train a baseline random forest model to predict the result of AVS from imaging alone. In a second step, clinical parameters were integrated. Model performance was assessed via area under the receiver operating characteristic curve (ROC AUC). Permutation feature importance was used to assess the predictive value of selected features.ResultsRadiomics features alone allowed only for moderate discrimination of the location of aldosterone overproduction with a ROC AUC of 0.57 for unilateral left (UL), 0.61 for unilateral right (UR), and 0.50 for bilateral (BI) aldosterone overproduction (total 0.56, 95% CI: 0.45-0.65). Integration of clinical parameters into the model substantially improved ROC AUC values (0.61 UL, 0.68 UR, and 0.73 for BI, total 0.67, 95% CI: 0.57-0.77). According to permutation feature importance, lowest potassium value at baseline and saline infusion test (SIT) were the two most important features.ConclusionIntegration of clinical parameters into a radiomics machine learning model improves prediction of the source of aldosterone overproduction and subtyping in patients with PA
Sphingosine 1-phosphate receptor expression profile and regulation of migration in human thyroid cancer cells
S1P (sphingosine 1-phosphate) receptor expression and the effects of S1P on migration were studied in one papillary (NPA), two follicular (ML-1, WRO) and two anaplastic (FRO, ARO) thyroid cancer cell lines, as well as in human thyroid cells in primary culture. Additionally, the effects of S1P on proliferation, adhesion and calcium signalling were addressed in ML-1 and FRO cells. All cell types expressed multiple S1P receptors. S1P evoked intracellular calcium signalling in primary cultures, ML-1 cells and FRO cells. Neither proliferation nor migration was affected in primary cultures, whereas S1P partly inhibited proliferation in ML-1 and FRO cells. Low nanomolar concentrations of S1P inhibited migration in FRO, WRO and ARO cells, but stimulated ML-1 cell migration. Consistently, S1P(1) and S1P(3), which mediate migratory responses, were strongly expressed in ML-1 cells, and S1P(2), which inhibits migration, was the dominating receptor in the other cell lines. The migratory effect in ML-1 cells was mediated by G(i) and phosphatidylinositol 3-kinase. Both S1P and the S1P(1)-specific agonist SEW-2871 induced Akt phosphorylation at Ser(473). However, SEW-2871 failed to stimulate migration, whereas the S1P(1)/S1P(3) antagonist VPC 23019 inhibited S1P-induced migration. The results suggest that aberrant S1P receptor expression may enhance thyroid cancer cell migration and thus contribute to the metastatic behaviour of some thyroid tumours
Diet-Induced Obesity Causes Severe but Reversible Leptin Resistance in Arcuate Melanocortin Neurons
Despite high leptin levels, most obese humans
and rodents lack responsiveness to its appetite-
suppressing effects. We demonstrate that
leptin modulates NPY/AgRP and a-MSH secretion
from the ARH of lean mice. High-fat dietinduced
obese (DIO) mice have normal ObRb
levels and increased SOCS-3 levels, but leptin
fails to modulate peptide secretion and any element
of the leptin signaling cascade. Despite
this leptin resistance, the melanocortin system
downstream of the ARH in DIO mice is overresponsive
to melanocortin agonists, probably
due to upregulation of MC4R. Lastly, we show
that by decreasing the fat content of the
mouse’s diet, leptin responsiveness of NPY/
AgRP and POMC neurons recovered simultaneously,
with mice regaining normal leptin sensitivity
and glycemic control. These results
highlight the physiological importance of leptin
sensing in the melanocortin circuits and show
that their loss of leptin sensing likely contributes
to the pathology of leptin resistance