Symptomatic Sinus Node Disease: Natural History After Permanent Ventricular Pacing *

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75403/1/j.1540-8159.1979.tb03650.x.pd

Gravitational Lensing at Millimeter Wavelengths

With today's millimeter and submillimeter instruments observers use gravitational lensing mostly as a tool to boost the sensitivity when observing distant objects. This is evident through the dominance of gravitationally lensed objects among those detected in CO rotational lines at z>1. It is also evident in the use of lensing magnification by galaxy clusters in order to reach faint submm/mm continuum sources. There are, however, a few cases where millimeter lines have been directly involved in understanding lensing configurations. Future mm/submm instruments, such as the ALMA interferometer, will have both the sensitivity and the angular resolution to allow detailed observations of gravitational lenses. The almost constant sensitivity to dust emission over the redshift range z=1-10 means that the likelihood for strong lensing of dust continuum sources is much higher than for optically selected sources. A large number of new strong lenses are therefore likely to be discovered with ALMA, allowing a direct assessment of cosmological parameters through lens statistics. Combined with an angular resolution <0.1", ALMA will also be efficient for probing the gravitational potential of galaxy clusters, where we will be able to study both the sources and the lenses themselves, free of obscuration and extinction corrections, derive rotation curves for the lenses, their orientation and, thus, greatly constrain lens models.Comment: 69 pages, Review on quasar lensing. Part of a LNP Topical Volume on "Dark matter and gravitational lensing", eds. F. Courbin, D. Minniti. To be published by Springer-Verlag 2002. Paper with full resolution figures can be found at ftp://oden.oso.chalmers.se/pub/tommy/mmviews.ps.g

Signature inversion in odd-odd nuclei

Trends in the energy staggering of the πh11/2νi13/2 and πh11/2νh11/2 bands in the mass 160 and 130 regions, respectively, have been investigated in order to better understand the origin of signature inversion. While the A ≈ 160 nuclei behave in a consistent manner, a more complicated'scenario is observed in the mass 130 region. As a result of our experiments on the lightest Pr nuclei, the systematics of these Z = 59 nuclei have been extended, which aids in the understanding of the latter region. Triaxial deformation, a pn interaction, and quadrupole pairing are considered as possible contributors to this effect. As all the chiral-twin bands that are known have signature inversion in the favored band, a possible link between the two phenomena should be considered

Airway mucus hyperconcentration in non–cystic fibrosis bronchiectasis

Rationale: Non–cystic fibrosis bronchiectasis is characterized by airway mucus accumulation and sputum production, but the role of mucus concentration in the pathogenesis of these abnormalities has not been characterized. Objectives: This study was designed to: 1) measure mucus concentration and biophysical properties of bronchiectasis mucus; 2) identify the secreted mucins contained in bronchiectasis mucus; 3) relate mucus properties to airway epithelial mucin RNA/protein expression; and 4) explore relationships between mucus hyperconcentration and disease severity. Methods: Sputum samples were collected from subjects with bronchiectasis, with and without chronic erythromycin administration, and healthy control subjects. Sputum percent solid concentrations, total and individual mucin concentrations, osmotic pressures, rheological properties, and inflammatory mediators were measured. Intracellular mucins were measured in endobronchial biopsies by immunohistochemistry and gene expression. MUC5B (mucin 5B) polymorphisms were identified by quantitative PCR. In a replication bronchiectasis cohort, spontaneously expectorated and hypertonic saline-induced sputa were collected, and mucus/mucin concentrations were measured. Measurements and Main Results: Bronchiectasis sputum exhibited increased percent solids, total and individual (MUC5B and MUC5AC) mucin concentrations, osmotic pressure, and elastic and viscous moduli compared with healthy sputum. Within subjects with bronchiectasis, sputum percent solids correlated inversely with FEV1 and positively with bronchiectasis extent, as measured by high-resolution computed tomography, and inflammatory mediators. No difference was detected in MUC5B rs35705950 SNP allele frequency between bronchiectasis and healthy individuals. Hypertonic saline inhalation acutely reduced non–cystic fibrosis bronchiectasis mucus concentration by 5%. Conclusions: Hyperconcentrated airway mucus is characteristic of subjects with bronchiectasis, likely contributes to disease pathophysiology, and may be a target for pharmacotherapy

Persistence of collective behavior at high spin in the N=88 nucleus Tb 153

Excited states in the N=88 nucleus Tb153 were observed up to spin ∼40 in an experiment utilizing the Gammasphere array. The Tb153 states were populated in a weak α4n evaporation channel of the Cl37 + Sn124 reaction. Two previously known sequences were extended to higher spins, and a new decoupled structure was identified. The πh11/2 band was observed in the spin region where other N=88 isotopes exhibit effects of prolate to oblate shape changes leading to band termination along the yrast line, whereas Tb153 displays a persistent collective behavior. However, minor perturbations of the very highest state in both signatures of this h11/2 band are observed, which perhaps signal the start of the transition towards band termination

High-spin terminating states in the N=88 Ho 155 and Er 156 isotones

The Sn124(Cl37,6nγ) fusion-evaporation reaction at a bombarding energy of 180 MeV has been used to significantly extend the excitation level scheme of 67155Ho88. The collective rotational behavior of this nucleus breaks down above spin I∼30 and a fully aligned noncollective (band terminating) state has been identified at Iπ=79/2-. Comparison with cranked Nilsson-Strutinsky calculations also provides evidence for core-excited noncollective states at Iπ=87/2- and (89/2+) involving particle-hole excitations across the Z=64 shell gap. A similar core-excited state in 68156Er88 at Iπ=(46+) is also presented

Macroalgal meadow habitats support fish and fisheries in diverse tropical seascapes

Canopy-forming macroalgae can construct extensive meadow habitats in tropical seascapes occupied by fishes that span a diversity of taxa, life-history stages and ecological roles. Our synthesis assessed whether these tropical macroalgal habitats have unique fish assemblages, provide fish nurseries and support local fisheries. We also applied a meta-analysis of independent surveys across 23 tropical reef locations in 11 countries to examine how macroalgal canopy condition is related to the abundance of macroalgal-associated fishes. Over 627 fish species were documented in tropical macroalgal meadows, with 218 of these taxa exhibiting higher local abundance within this habitat (cf. nearby coral reef) during at least one life-history stage. Major overlap (40%–43%) in local fish species richness among macroalgal and seagrass or coral reef habitats suggest macroalgal meadows may provide an important habitat refuge. Moreover, the prominence of juvenile fishes suggests macroalgal meadows facilitate the triphasic life cycle of many fishes occupying diverse tropical seascapes. Correlations between macroalgal canopy structure and juvenile abundance suggests macroalgal habitat condition can influence levels of replenishment in tropical fish populations, including the majority of macroalgal-associated fishes that are targeted by commercial, subsistence or recreational fisheries. While many macroalgal-associated fishery species are of minor commercial value, their local importance for food and livelihood security can be substantial (e.g. up to 60% of landings in Kenyan reef fisheries). Given that macroalgal canopy condition can vary substantially with sea temperature, there is a high likelihood that climate change will impact macroalgal-associated fish and fisheries