What is theoretical progress of science?

The epistemic conception of scientific progress equates progress with accumulation of scientific knowledge. I argue that the epistemic conception fails to fully capture scientific progress: theoretical progress, in particular, can transcend scientific knowledge in important ways. Sometimes theoretical progress can be a matter of new theories ‘latching better onto unobservable reality’ in a way that need not be a matter of new knowledge. Recognising this further dimension of theoretical progress is particularly significant for understanding scientific realism, since realism is naturally construed as the claim that science makes theoretical progress. Some prominent realist positions (regarding fundamental physics, in particular) are best understood in terms of commitment to theoretical progress that cannot be equated with accumulation of scientific knowledge

Cross-talk between cd1d-restricted nkt cells and γδ cells in t regulatory cell response

CD1d is a non-classical major histocompatibility class 1-like molecule which primarily presents either microbial or endogenous glycolipid antigens to T cells involved in innate immunity. Natural killer T (NKT) cells and a subpopulation of γδ T cells expressing the Vγ4 T cell receptor (TCR) recognize CD1d. NKT and Vγ4 T cells function in the innate immune response via rapid activation subsequent to infection and secrete large quantities of cytokines that both help control infection and modulate the developing adaptive immune response. T regulatory cells represent one cell population impacted by both NKT and Vγ4 T cells. This review discusses the evidence that NKT cells promote T regulatory cell activation both through direct interaction of NKT cell and dendritic cells and through NKT cell secretion of large amounts of TGFβ, IL-10 and IL-2. Recent studies have shown that CD1d-restricted Vγ4 T cells, in contrast to NKT cells, selectively kill T regulatory cells through a caspase-dependent mechanism. Vγ4 T cell elimination of the T regulatory cell population allows activation of autoimmune CD8+ effector cells leading to severe cardiac injury in a coxsackievirus B3 (CVB3) myocarditis model in mice. CD1d-restricted immunity can therefore lead to either immunosuppression or autoimmunity depending upon the type of innate effector dominating during the infection

Effects of Single-Sex Schooling in the Final Years of High School: A Comparison of Analysis of Covariance and Propensity Score Matching

Typically, the effects of single-sex schooling are small at best, and tend to be statistically non-significant once pre-existing differences are taken into account. However, researchers often have had to rely on observational studies based on small non-representative samples and have not used more advanced propensity score methods to control the potentially confounding effects of covariates. Here, we apply optimal full matching to the large historical longitudinal dataset best suited to evaluating this issue in US high schools: the nationally representative High School and Beyond study. We compare the effects of single-sex education in the final 2 years of high school on Grade 12 and post-secondary outcomes using the subsample of students attending Catholic schools (N = 2379 students, 29 girls' schools, 22 boys' schools, 33 coeducational schools) focusing on achievement-related, motivational and social outcomes. We contrast conventional Analysis of Covariance (ANCOVA) with optimal full matching based on the propensity score that provides a principled way of controlling for selection bias. Results from the two approaches converged: When background and Year 10 covariates were controlled, uncorrected apparent differences between the school types disappeared and the pattern of effects was very similar across the two methods. Overall, there was little evidence for positive effects of single-sex schooling for a broad set of outcomes in the final 2 years of high school and 2 years after graduation. We conclude with a discussion of the advantages of propensity score methods compared to ANCOVA