Assessment of the uncertainties in temperature change in China during the last century

We have used the China Homogenized Historic Temperature dataset and some long-term station series of the neighbor countries from CRUTEM3, a 5°×5° gridded dataset of monthly mean temperature since 1900, to provide a 107-year record of surface tem-perature trends and variability. We derived a comprehensive set of uncertainty estimates to accompany the data: measurement and sampling errors, uncertainties in temperature bias estimates, and uncertainties arising from limited observational coverage on large-scale averages have all been estimated. We reanalysed the temperature changes during the period of record. The best estimates of trends for 1900–2006 with uncertainties at 95% confidence range are about 0.09±0.017°C/decade for the year as a whole, and 0.14±0.021°C/decade, 0.11±0.021°C/decade, 0.04±0.017°C/decade, and 0.07±0.017°C/decade for winter, spring, summer and autumn respectively. For 1954–2006, the trends for annual, winter, spring, summer and autumn are: 0.26±0.032°C/decade, 0.35±0.046°C/decade, 0.25±0.051°C/decade, 0.16±0.037°C/decade and 0.22±0.055°C/decade. Winter saw the most significant warming trend in both 1900–2006 and 1954–2006, while during the most recent period (the satellite era, 1979–2006), all the seasons show similar warming trends: 0.45±0.13°C/decade, 0.51±0.11°C/decade, 0.52±0.16°C/decade, 0.37±0.10°C/decade and 0.50±0.16°C/decade for annual, winter, spring, summer and autumn. Trends arising from urbanization have been evaluated as less than 5% of the total warming trend for 1951–2001, so this bias was not removed.     

A recurrent mutation in MED12 leading to R961W causes Opitz-Kaveggia syndrome

Opitz-Kaveggia syndrome (also known as FG syndrome) is an X-linked disorder characterized by mental retardation, relative macrocephaly, hypotonia and constipation. We report here that the original family for whom the condition is named and five other families have a recurrent mutation (2881C>T, leading to R961W) in MED12 (also called TRAP230 or HOPA), a gene located at Xq13 that functions as a thyroid receptor-associated protein in the Mediator complex.     

Human cardiovascular progenitor cells develop from a KDR+ embryonic-stem-cell-derived population

The functional heart is comprised of distinct mesoderm-derived lineages including cardiomyocytes, endothelial cells and vascular smooth muscle cells. Studies in the mouse embryo and the mouse embryonic stem cell differentiation model have provided evidence indicating that these three lineages develop from a common Flk-1(+) (kinase insert domain protein receptor, also known as Kdr) cardiovascular progenitor that represents one of the earliest stages in mesoderm specification to the cardiovascular lineages. To determine whether a comparable progenitor is present during human cardiogenesis, we analysed the development of the cardiovascular lineages in human embryonic stem cell differentiation cultures. Here we show that after induction with combinations of activin A, bone morphogenetic protein 4 (BMP4), basic fibroblast growth factor (bFGF, also known as FGF2), vascular endothelial growth factor (VEGF, also known as VEGFA) and dickkopf homolog 1 (DKK1) in serum-free media, human embryonic-stem-cell-derived embryoid bodies generate a KDR(low)/C-KIT(CD117)(neg) population that displays cardiac, endothelial and vascular smooth muscle potential in vitro and, after transplantation, in vivo. When plated in monolayer cultures, these KDR(low)/C-KIT(neg) cells differentiate to generate populations consisting of greater than 50% contracting cardiomyocytes. Populations derived from the KDR(low)/C-KIT(neg) fraction give rise to colonies that contain all three lineages when plated in methylcellulose cultures. Results from limiting dilution studies and cell-mixing experiments support the interpretation that these colonies are clones, indicating that they develop from a cardiovascular colony-forming cell. Together, these findings identify a human cardiovascular progenitor that defines one of the earliest stages of human cardiac development.     

Murine T lymphomas with retroviral inserts in the chromosomal 15 locus for plasmacytoma variant translocations

The frequent trisomy of murine chromosome 15 in T lymphomas suggests that it bears one or more genes conducive to T-cell neoplasia. One such gene seems to be c-myc, the oncogene frequently activated in B-lymphoid tumours either by retroviral insertion, as in the avian bursal lymphomas, or by a translocation to the immunoglobulin heavy-chain locus, as in the predominant t(12; 15) of murine plasmacytomas and the analogous t(14; 8) of human Burkitt lymphomas. The c-myc gene was strongly implicated in T-cell neoplasia when 15-25% of T lymphomas arising in AKR mice, a strain prone to leukaemia, were found to have retroviral inserts near c-myc. Proviruses near c-myc were also found in several T lymphomas induced by murine leukaemia viruses (MuLV) in both mice and rats, but many of the rat thymomas bear an insert instead at one of several other common sites, at least two of which have murine homologues on chromosome 15. We show here that some murine T lymphomas contain proviral inserts in the recently identified chromosome 15 locus for plasmacytoma variant (6; 15) translocations, which we have denoted pvt-1. Although 6; 15 breakpoints map cytogenetically to the same chromosome band as c-myc, the alterations of pvt-1 in tumours occur at least 72 kilobases (kb) from the c-myc promoters. The insertions in T lymphomas suggest that an altered pvt-1 locus is conducive to neoplasia in T cells as well as B cells, possibly via long-range effects on c-myc expression.     

Extraadrenal adrenaline formation by two separate enzymes

Summary Adrenaline (A) is synthesized in the adrenal medullae by the enzyme phenylethanolamine-N-methyltransferase (PNMT). After surgical removal of the adrenal medullae tissue A levels ranged from 22% of control in the heart to 125% of control in the liver. Use of a novel assay to measure tissue A formation revealed that many tissues can synthesize A using PNMT and another enzyme that N-methylates both noradrenaline and dopamine. These enzymes are non-neuronal, inducible and synthesize a major fraction of tissue and urine A.     

Atomism and ‘subtlety’ in Francis Bacon's philosophy

Francis Bacon's reflections on atomism have generally been misunderstood because they have never been systematically studied in relation to the speculative chemical philosophy which he developed in the interval between about 1592 and his death in 1626. This philosophy, in many respects unknown to historians until quite recently, was the only body of positive science which Bacon ever accepted. The speculative philosophy was, on the whole, chemical and non-mechanical, and consequently not consistent with atomist doctrines. In fact, Bacon never at any time accepted the principal atomist tenets. It is therefore necessary to explain why he was interested in atomism at all. Of the several reasons for his interest one (hitherto unrecognised) is especially important—namely, his belief that the speculative and atomic philosophies had affinities. In particular, he believed that of all the ancient philosophies atomism alone approached the ideals associated with the key notion of ‘subtlety’—ideals represented in their highest form (as he imagined) in the speculative philosophy.     

A non representationalist view of model explanation

In this paper, I examine two idealized models in astrophysics, with the aim of showing that the idealizations in these models play an important explanatory role. I argue, against many representationalists, that it is because of the idealizations in these models, rather than in spite of them, that the models turn out to have explanatory power. In many cases, this claim can be extended to the use of idealized models in the sciences more generally, and thus it gives important insight into the nature of model explanation.