Rigorous Probabilistic Analysis of Equilibrium Crystal Shapes

The rigorous microscopic theory of equilibrium crystal shapes has made enormous progress during the last decade. We review here the main results which have been obtained, both in two and higher dimensions. In particular, we describe how the phenomenological Wulff and Winterbottom constructions can be derived from the microscopic description provided by the equilibrium statistical mechanics of lattice gases. We focus on the main conceptual issues and describe the central ideas of the existing approaches.Comment: To appear in the March 2000 special issue of Journal of Mathematical Physics on Probabilistic Methods in Statistical Physic

Cultural Representativeness in the Principles of AI

Artificial intelligence (AI) applications have reached a wide range of domains and have raised concerns over fairness, accountability, transparency, and ethics. For example, social media platforms face challenges from Congress over data privacy and facial recognition software have been racially biased. Accordingly, society is actively establishing principles to govern the development and application of AI technologies; examples include General Data Protection Regulation (GDPR). But, as AI innovation disseminates across cultural and political boundaries, how do societies in different cultures perceive these high-level AI principles? What are the acceptable ground rules for global AI governance? This project seeks to answer these by studying the interactions between cultural norms, the public opinion of AI, and the AI research community. To understand how key AI principles resonate amongst different cultures, we will study knowledge production and dissemination. Our approach is informed by the studies in comparative philosophy, which contrast moral traditions developed along relatively isolated cultural and regional lines. We will combine data science, qualitative studies, and mixed-methods approach to analyze micro- and macroscopic data. This project will build synergy among distinct disciplines represented by the team, including Philosophy and Ethics, Data and Information Sciences, Psychology, and Anthropology

Pseudoscientific Health Beliefs and the Perceived Frequency of Causal Relationships

Beliefs about cause and effect, including health beliefs, are thought to be related to the frequency of the target outcome (e.g., health recovery) occurring when the putative cause is present and when it is absent (treatment administered vs. no treatment); this is known as contingency learning. However, it is unclear whether unvalidated health beliefs, where there is no evidence of cause–effect contingency, are also influenced by the subjective perception of a meaningful contingency between events. In a survey, respondents were asked to judge a range of health beliefs and estimate the probability of the target outcome occurring with and without the putative cause present. Overall, we found evidence that causal beliefs are related to perceived cause–effect contingency. Interestingly, beliefs that were not predicted by perceived contingency were meaningfully related to scores on the paranormal belief scale. These findings suggest heterogeneity in pseudoscientific health beliefs and the need to tailor intervention strategies according to underlying causes

Pharmacological characterization of the chemokine receptor, hCCR1 in a stable transfectant and differentiated HL-60 cells: antagonism of hCCR1 activation by MIP-1β

1. C-C chemokine receptor-1 (CCR1) has been implicated in mediating a variety of inflammatory conditions including multiple sclerosis and organ rejection. Although originally referred to as the MIP-1α/RANTES receptor, CCR1 is quite promiscuous and can be activated by numerous chemokines. 2. We used radioligand binding and [(35)S]-GTPγS exchange assays in membranes from a cell line transfected to express CCR1 (Ba/F3-hCCR1) to characterize a panel of chemokines (HCC-1, MIP-1α, MIP-1β, MIP-1δ, MPIF-1, MCP-2, MCP-3, and RANTES) as CCR1 ligands. In this recombinant model, these chemokines displaced (125)I-MIP-1α with a wide range of potencies and, with the exception of MCP-2, acted as full agonists in stimulating [(35)S]-GTPγS exchange. 3. We then assessed the utility of HL-60 cells cultured with known differentiating agents (PMA, DMSO, dibutyryl-cAMP or retinoic acid) for investigating CCR1 pharmacology. In [(35)S]-GTPγS exchange assays, membranes from cells cultured with retinoic acid (4–6 days) were the most responsive to activation by MIP-1α and MPIF-1. FACS analysis and comparative pharmacology confirmed that these activities were mediated by CCR1. 4. Using [(35)S]-GTPγS exchange assays, intracellular calcium flux and/or whole cell chemotaxis assays in HL-60(Rx) cells, we validated that MIP-1α was the most potent CCR1 ligand (MIP-1α>MPIF-1>RANTES⩾MIP-1β) although the ligands differed in their efficacy as agonists. MPIF-1 was the more efficacious (MPIF-1>RANTES=MIP-1α>>MIP-1β). (125)I-MIP-1β binding in Ba/F3-hCCR1 and HL-60(Rx) membranes was competitively displaced by MIP-1α, MPIF-1 and MIP-1β. The binding K(i) for these chemokines with (125)I-MIP-1β were essentially identical in the two membrane systems. 5. Lastly, MIP-1β antagonized [(35)S]-GTPγS exchange, Ca(2+) flux and chemotaxis in HL-60(Rx) cells in response to robust agonists such as MIP-1α, RANTES and MPIF-1. Based on our results, we propose that MIP-1β could function as an endogenous inhibitor of CCR1 function

Thirty Years of Interplanetary Background Data: A Global View

This chapter compares results of models of the interplanetary background, such as the one presented in Chap.1, to different datasets obtained in the outer heliosphere (Voyager-UVS, Alice New-Horizons) and in the inner heliosphere (SWAN-SOHO, STIS-HST). The aim of this work is to combine these datasets and the models and to derive calibration factors that give a coherent picture of the various instruments and the interplanetary background. These datasets do not overlap and the models are used to bridge the gaps in distance or in time. In the case of Voyager 1 and 2 UVS instruments, the calibration factors derived here are significantly different from the values published by Hall (Ultraviolet resonance radiation and the structure of the heliosphere. Dissertation, University of Arizona, 1992)

Expression of rat I-TAC/CXCL11/SCYA11 during central nervous system inflammation: comparison with other CXCR3 ligands

© 2007 United States and Canadian Academy of PathologyThe chemokines are a large gene superfamily with critical roles in development and immunity. The chemokine receptor CXCR3 appears to play a major role in the trafficking of activated Th1 lymphocytes. There are at least three major ligands for CXCR3: mig/CXCL9, IP-10/CXCL10 and I-TAC/CXCL11, and of these three ligands, CXCL11 is the least well-characterized. In this study, we have cloned a rat ortholog of CXCL11, evaluated its function, and examined its expression in the Th-1-mediated disease, experimental autoimmune encephalomyelitis (EAE) in the rat. Based on its predicted primary amino-acid sequence, rat I-TAC/CXCL11 was synthesized and shown to induce chemotaxis of activated rat T lymphocytes in vitro and the in vivo migration of T lymphocytes when injected into the skin. I-TAC/CXCL11 expression, as determined by RT-PCR, increased in lymph node and spinal cord tissue collected from rats in which EAE had been actively induced, and in spinal cord tissue from rats in which EAE had been passively induced. The kinetics of expression were similar to that of CXCR3 and IP-10/CXCL10, although expression of both CXCR3 and IP-10/CXCL10 was more intense than that of I-TAC/CXCL11 and increased more rapidly in both lymph nodes and the spinal cord. Only minor levels of expression of the related chemokine mig/CXCL9 were observed. Immunohistochemistry revealed that the major cellular source of I-TAC/CXCL11 in the central nervous system (CNS) during EAE is likely to be the astrocyte. Together, these data indicate that I-TAC/CXCL11 is expressed in the CNS during the clinical phase of EAE. However, the observation that I-TAC/CXCL11 is expressed after receptor expression is detected suggests that it is not essential for the initial migration of CXCR3-bearing cells into the CNS.Shaun R McColl, Surendran Mahalingam, Maria Staykova, Laurie A Tylaska, Katherine E Fisher, Christine A Strick, Ronald P Gladue, Kuldeep S Neote and David O Willenbor