Living on the edge of stability, the limits of the nuclear landscape

A first-principles description of nuclear systems along the drip lines presents a substantial theoretical and computational challenge. In this paper, we discuss the nuclear theory roadmap, some of the key theoretical approaches, and present selected results with a focus on long isotopic chains. An important conclusion, which consistently emerges from these theoretical analyses, is that three-nucleon forces are crucial for both global nuclear properties and detailed nuclear structure, and that many-body correlations due to the coupling to the particle continuum are essential as one approaches particle drip lines. In the quest for a comprehensive nuclear theory, high performance computing plays a key role.Comment: Contribution to proceedings of Nobel Symposium 152: Physics with radioactive beams, June 2012, Gothenburg, Swede

International genome-wide meta-analysis identifies new primary biliary cirrhosis risk loci and targetable pathogenic pathways.

Primary biliary cirrhosis (PBC) is a classical autoimmune liver disease for which effective immunomodulatory therapy is lacking. Here we perform meta-analyses of discovery data sets from genome-wide association studies of European subjects (n=2,764 cases and 10,475 controls) followed by validation genotyping in an independent cohort (n=3,716 cases and 4,261 controls). We discover and validate six previously unknown risk loci for PBC (Pcombined<5 × 10(-8)) and used pathway analysis to identify JAK-STAT/IL12/IL27 signalling and cytokine-cytokine pathways, for which relevant therapies exist

Effects of Preparation and Fixation on Three Quantitative Fluorescent Cytochemical Procedures

A series of experiments was undertaken in which cells dissociated from the abdominal lymph nodes of mice were lightly centrifuged into slides and fixed either wet or after drying in 70% ethanol, 1% glutaraldehyde, 1% formaldehyde, or neutral formalin. Three fluorescent cytochemical methods were evaluated: staining of DNA with mithramycin; fluorochroming of basic groups of proteins with brilliant sulfaflavine (BSF); and staining of sulfhydryl and disulfide groups with N-(7-dimethylamino-4-methylcoumarinyl)maleimide (DACM). In the case of mithramycin, the best results were obtained after fixation in 70% ethanol without drying. Staining of dried preparations fixed in 1% glutaraldehyde also yielded reasonably consistent results, although the fluorescence was lower, and the variability higher, than in the group fixed without drying in 70% ethanol. The use of fixatives containing formaldehyde resulted in fluorescence values of only about onethird those of the other two groups, and the variability of the data was higher. In material stained with BSF, satisfactory results were obtained in preparations fixed without drying in neutral formalin containing mersalyl acid. Other fixatives could be used, but the resulting coefficients of variation were higher than those of formalin-fixed material. Sulfhydryl to disulfide ratios approaching those expected from biochemical evidence were obtained in DACM-stained material only after fixation without drying in neutral formalin containing mersalyl acid. Inverted sulfhydryl-disulfide ratios were observed in material fixed without drying in 70% ethanol; and in dried metarial fixed in 1% formaldehyde, neutral formalin, or 1% glutaraldehyde

Demonstration of Sulfhydryl and Disulfide Groups by a Fluorescent Maleimide Procedure

Several fluorescent maleimide compounds were evaluated as possible substitutes for N-(4-aminophenyl)maleimide in the histochemical procedures developed by Sippel (1973, 1978a, b, 1980) for the demonstration of sulfhydryl and disulfide groups. The brightest and most selective fluorescence was obtained by using N-(7-dimethylamino-4-methylcoumarinyl)maleimide (DACM), although both eosin-5-maleimide and fluorescein-5-maleimide could also be used if adequate control preparations were made

Ultrastructure and Histochemistry of the Supportive Structures Associated With the Radula of the Slug, Limax Maximus

The odontophore and connective tissue‐filled portion of the radular sac (called the “collostyle”) of the slug, Limax maximus, were examined by light and electron microscopy. While both of these structures grossly resemble vertebrate cartilage, neither is composed of a type of tissue with the microscopic appearance and histochemical properties of cartilage. The roughly U‐shaped odontophore possesses a thin capsule composed of connective tissue. The parenchyma of the odontophore consists of modified muscle cells which are organized into irregular groups by incomplete trabeculae composed of conventional muscle cells. The odontophoral cells are variable in size; they contain glycogen‐filled “cores” as well as bundles of peripherally located filaments resembling myofilaments; and they are innervated like muscle cells. The nuclei of the cells are located eccentrically in the glycogen‐filled portions of the cells and typically contain prominent nucleoli. The nuclei are surrounded by multiple small Golgi complexes and pleomorphic dense bodies resembling lysosomes. The extracellular matrix of the odontophore is very sparse and contains glycogen and fibrillar material but no histochemically demonstrable acidic mucosubstances. The collostyle consists of a gelatinous type of tissue somewhat like vertebrate mucoid connective tissue. The abundant extracellular matrix contains cross banded filaments, a flocculent material disposed in wavy indefinite strands, and small electron‐dense particles. The matrix contains histochemically demonstrable neutral and weakly acidic mucosubstances. The cell population of the collostyle includes solitary muscle cells and fibrocytes containing large quantities of glycogen

Histochemical and Ultrastructural Features of the Aorta of the Slug (Limax maximus)

As a part of a continuing study of unusual molluscan tissues, the “chondroid” tissue (Hyman, \u2767) associated with the anterior and posterior aortae of the slug (Limax maximus) was examined by light and electron microscopy. Unlike the odontophoral tissue of this species (Curtis and Cowden, \u2777), the “chondroid” tissue comprising the adventitial layer of the aorta consists of large, glycogen‐filled cells with characteristic arrays of pores in their plasma membranes resembling those of the “globular” cells (Rogers, \u2769; Fernandez, \u2771); “fibrocytes” (Nicaise et al., \u2766; Baleydier et al., \u2769; Nicaise, \u2773); “Blasenzellen” or “Leydig” cells (Wondrak, \u2769; Stang‐Voss, \u2770; Buchholz et al., \u2771; Stang‐Voss and Staubesand, \u2771; Wolburg‐Buchholz, \u2772); or “pore” cells (Sminia, \u2772; Beltz, \u2777) of other mollusks. The anterior and posterior aortae are very similar in organization, except that the anterior aorta is larger in diameter; its wall is thinner; and it lacks calcification. Both the anterior and posterior aortae possess a loosely organized (incomplete) endothelial layer surrounded by two layers of innervated smooth muscle. The smooth muscle cells possess fibrous surface specializations resembling hemidesmosomes as well as large numbers of tubular or rounded vesicles in association with their plasma membranes. Blood cells (amoebocytes) containing large glycogen deposits and distinctive membrane‐enclosed cytoplasmic inclusions can be found occasionally in the walls of the vessels

A Fluorescent Water Soluable Carbodiimide-2-Hydroxy-3-Naphthoic Acid Hydrozide Reaction for the Demonstration of Carboxyl Groups in Proteins and Mucosubstances

The carbodiimide-2-hydroxy-3-naphthoic acid hydrazide reaction as developed by Geyer (1964) was used without subsequent diazonium coupling as a fluorescent method for the demonstration of carboxyl groups in both proteins and mucosubstances. The topological distribution of the fluorophore was similar to that reported by Geyer. Quantitative microfluorometric studies on cartilage sections revealed differences in detail between emissions in cartilage matrix mucoprotein as compared to the dense connective tissue associated with the perichondrium which consists principally of protein. It would also appear that the primary fluorescent emission of unstained preparations at 450 mm should be useful in microfluorometric determinations of proteins

A Comparison of Two Methods of Preparing Cells or Nuclei for High-Resolution Microspectrophotometry

Suspensions of isolated mouse thymus cells were subjected to two preparative methods: either they were dropped through several mm of 9:1 v/v ethanol-acetic acid fixative, allowed to stand for 1 hr and then processed for staining; or they were fixed, passed through a graded ethanol series to 70% ethanol, centrifuged on to slides in a modified Shandon cytocentrifuge and then carried wet into the staining procedure. All preparations were stained by the Feulgen reaction and evaluated by high-resolution microspectrophotometry. While the two preparative procedures yielded similar results, there appeared to be less variability in the data obtained from the centrifuged cell populations