The present study explores the plausibility of measuring personality indirectly through an artificial intelligence (AI) chatbot. This chatbot mines various textual features from users' free text ...responses collected during an online conversation/interview and then uses machine learning algorithms to infer personality scores. We comprehensively examine the psychometric properties of the machine-inferred personality scores, including reliability (internal consistency, split-half, and test-retest), factorial validity, convergent and discriminant validity, and criterion-related validity. Participants were undergraduate students (n = 1,444) enrolled in a large southeastern public university in the United States who completed a self-report Big Five personality measure (IPIP-300) and engaged with an AI chatbot for approximately 20-30 min. In a subsample (n = 407), we obtained participants' cumulative grade point averages from the University Registrar and had their peers rate their college adjustment. In an additional sample (n = 61), we obtained test-retest data. Results indicated that machine-inferred personality scores (a) had overall acceptable reliability at both the domain and facet levels, (b) yielded a comparable factor structure to self-reported questionnaire-derived personality scores, (c) displayed good convergent validity but relatively poor discriminant validity (averaged convergent correlations = .48 vs. averaged machine-score correlations = .35 in the test sample), (d) showed low criterion-related validity, and (e) exhibited incremental validity over self-reported questionnaire-derived personality scores in some analyses. In addition, there was strong evidence for cross-sample generalizability of psychometric properties of machine scores. Theoretical implications, future research directions, and practical considerations are discussed.
The mammalian liver's regenerative ability has led researchers to engineer animals as incubators for expansion of human hepatocytes. The expansion properties of human hepatocytes in immunodeficient ...mice are well known. However, little has been reported about larger animals that are more scalable and practical for clinical purposes. Therefore, we engineered immunodeficient swine to support expansion of human hepatocytes and identify barriers to their clinical application. Immunodeficient swine were engineered by knockout of the recombinase-activating gene 2 (
RAG2
) and fumarylacetoacetate hydrolase (FAH). Immature human hepatocytes (ihHCs) were injected into fetal swine by intrauterine cell transplantation (IUCT) at day 40 of gestation. Human albumin was measured as a marker of engraftment. Cytotoxicity against ihHCs was measured in transplanted piglets and control swine. We initially detected higher levels of human albumin in cord blood of newborn FAH/
RAG2
-deficient (FR) pigs compared with immunocompetent controls (196.26 ng/dL vs. 39.29 ng/dL,
p
= 0.008), indicating successful engraftment of ihHCs after IUCT and adaptive immunity in the fetus. Although rare hepatocytes staining positive for human albumin were observed, levels of human albumin did not rise after birth, but declined, suggesting rejection of xenografted ihHCs. Cytotoxicity against ihHCs increased after birth by 3.8% (95% CI: 2.1%–5.4%,
p
< 0.001) and inversely correlated with declining levels of human albumin (
p
= 2.1 × 10
−5
,
R
2
= 0.17). Circulating numbers of T cells and B cells were negligible in FR pigs. However, circulating natural killer (NK) cells exerted cytotoxicity against ihHCs. NK cell activity was lower in immunodeficient piglets after IUCT than in naive controls (30.4% vs. 40.1%,
p
= 0.011, 95% CI for difference 2.7%–16.7%). In conclusion, ihHCs were successfully engrafted in FR swine after IUCT. NK cells were a significant barrier to expansion of hepatocytes. New approaches are needed to overcome this hurdle and allow large-scale expansion of human hepatocytes in immunodeficient swine.
Background:
The contribution of genetic variants underlying the susceptibility to different clinical courses of multiple sclerosis (MS) is still unclear.
Objective:
The aim of the study is to ...evaluate and compare the proportion of liability explained by common SNPs and the genetic burden of MS-associated SNPs in progressive onset (PrMS) and bout-onset (BOMS) cases.
Methods:
We estimated the proportion of variance in disease liability explained by 296,391 autosomal SNPs in cohorts of Italian PrMS and BOMS patients using the genome-wide complex trait analysis (GCTA) tool, and we calculated a weighted genetic risk score (wGRS) based on the known MS-associated loci.
Results:
Our results identified that common SNPs explain a greater proportion of phenotypic variance in BOMS (36.5%±10.1%) than PrMS (20.8%±6.0%) cases, and a trend of decrease was observed when testing primary progressive (PPMS) without brain MRI inflammatory activity (p = 7.9 × 10−3). Similarly, the wGRS and the variance explained by MS-associated SNPs were higher in BOMS than PPMS in males (wGRS: 6.63 vs 6.51, p = 0.04; explained variance: 4.8%±1.5% vs 1.7%±0.6%; p = 0.05).
Conclusions:
Our results suggest that the liability of disease is better captured by common genetic variants in BOMS than PrMS cases. The absence of inflammatory activity and male gender further raise the difference between clinical courses.
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