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The Lung Volume Reduction Coil Treatment in Patients With Emphysema (RENEW) trial reported improvements in quality of life, pulmonary function, and exercise performance following endobronchial coil treatment.

This article presents a collection of letters to the editor. There are several on the Iraq war as reported in the September 17, 2007, issue. There is a letter regarding prostate cancer research and one on America's transportation system, both also from the Sept. 17 issue.

The distances and orientations among the C5‘ methyl group of 5‘-deoxyadenosine, the radical-bearing C1 carbon of the substrate radical, and the low spin (S=1/2) Co^II in cob(II)alamin in the active site of coenzyme B12-dependent ethanolamine deaminase from Salmonella typhimurium have been characterized in the Co^II-substrate radical pair state by using two-pulse X-band electron spin−echo electron paramagnetic resonance (ESE-EPR) and electron spin−echo envelope modulation (ESEEM) spectroscopies in the disordered solid state. Our approach is based on the orientation-selection created in the EPR spectrum of the biradical by the axial electron−electron dipolar interaction. Simulation of the ESE-EPR line shape yielded Co^II-radical exchange and dipole interaction terms, which were used to calculate the Co^II-C1 distance of 11.1 Å and the dependence of the EPR line shape on the angle between the Co^II-C1 axis and the magnetic field vector. ESEEM spectroscopy performed at four magnetic field values addressed the coupling between ²H in the C5‘ methyl group and the unpaired spin on C1. Global ESEEM simulations, weighted by the orientation dependence of the EPR line shape, were performed for the four magnetic fields. The C1−H distance and orientation with respect to the Co^II-C1 axis are specified for each C5‘ methyl hydrogen atom. In the derived model of the active site, C5‘ is located close to the Co^II-C1 axis (at distances of 7.8 Å and 3.3 Å from Co^II and C1, respectively) while the C1−H−C5‘ angle for the strongly coupled hydrogen is 165°. The near collinearity of the cobalt−carbon bond axis, radical migration coordinate and hydrogen atom transfer coordinate suggests an economy of nuclear displacements within the active site that would minimize rate-slowing molecular reorganization during the long-range radical pair separation.

Steel factor (SLF) is a hematopoietic cytokine that synergizes with other growth factors to induce a greatly enhanced proliferative state of hematopoietic progenitor cells and factor-dependent cell lines. Even though the in vivo importance of SLF in the maintenance and responsiveness of stem and progenitor cells is well documented, the molecular mechanism involved in its synergistic effects are mainly unknown. Some factor-dependent myeloid cell lines respond to the synergistic proliferative effects of SLF plus other cytokines in a manner similar to that of normal myeloid progenitor cells from bone marrow and cord blood. We show here that SLF can synergize with granulocyte-macrophage colony-stimulating factor (GM-CSF) to induce an enhanced phosphorylation of the retinoblastoma gene product and a synergistic increase in the total intracellular protein level of the cyclin-dependent kinase inhibitor, p21cip-1, which is correlated with a simultaneous decrease in p27kip-1 in the human factor-dependent myeloid cell line, M07e. Moreover, these cytokines synergize to increase p21cip- 1 binding and decrease p27kip-1 binding to cyclin-dependent kinase-2 (cdk2), an enzyme required for normal cell cycle progression; these inverse events correlated with increased cdk2 kinase activity. It is also shown that exogenous purified p21cip-1 can displace p27kip-1 already bound to cdk2 in vitro. These data implicate increased p21cip-1 and decreased p27kip-1 intracellular concentrations and their stoichiometric interplay in the enhanced proliferative status of cells stimulated by the combination of SLF and GM-CSF. In support of these findings, it is shown that hematopoietic progenitor cells from mice lacking p21cip-1 are defective in SLF synergistic proliferative response in vitro. Moreover, the cycling status of marrow and spleen progenitors and absolute numbers of marrow progenitors were significantly decreased in the p21cip-1 -/-, compared with the +/+ mice. We conclude that the cdk threshold regulators p21cip-1 and p27kip- 1 play a critical role in the normal mitogenic response of M07e cells and murine myeloid progenitor cells to these cytokines and particularly in the SLF synergistic proliferative response that is important to the normal maintenance of the stem/progenitor cell compartment.

The Mauthner (M-) cells, a bilateral pair of medullary neurons in fish, initiate the characteristic “C-start” predatory escape response of teleosts. Similar movements have been described during hatching, social interactions, and feeding. M-cell firing, however, has not been correlated directly with these other behaviors. The objective of this study was to determine whether the M-cell, in addition to escape, plays a role in feeding.1.Goldfish were chronically implanted with electrodes positioned near the axon cap of one of the two M-cells. Subsequently, M-cell activity was monitored for up to 8 days while fish were surface feeding on live crickets.2.The M-cell fires and the fish performs a C-shaped flexion in association with the terminal phase of prey capture. Thus, the M-cell is active in the context of at least two behaviors, predator escape and prey capture, and may be considered a part of behaviorally shared neural circuitry.3.For the goldfish, Mauthner-initiated flexions during feeding rapidly remove the prey from the water's surface and minimizes the fish's own susceptibility to surface predation. Other species may possess a diverse repertoire of Mauthner-mediated feeding behaviors that depend on their adaptive specializations for predation. Moreover, group competition between predators and their prey may have facilitated a “neural arms race” for M-cell morphology and physiology.

Once initiated, rapid escape responses of teleost fishes are thought to be completed without additional sensory modification. This suggests that the motor program for a particular response is selected for by the constellation of sensory cues existing at the time of the releasing stimulus. This paper presents initial evidence that a highly specialized, phylogenetically recent electrosensory system is integrated with a primitive motor system and allows an animal to continuously monitor its environment for producing accurate escape behaviors.

Presented are the results of an experimental effort to quantify some of the heat transfer parameters pertaining to the luminous flame that results from the uncontrolled combustion of an 8-ft × 16-ft pool of JP-5 aviation fuel. The temperature and effective total radiant heat flux, both as temporal mean quantities, were measured as functions of position within the quasi-steady burning flame as it existed in a quiescent atmosphere. A grid of infrared radiometers and radiation-shielded thermocouples served as the primary sensing equipment. A determination was made of the perimeter-mean convection coefficient applicable to a horizontally oriented, smooth, 8.530-in-dia circular cylinder immersed at a particular location within the JP-5 flame. The value of this coefficient was the result of a solution to a nonlinear, inverse conduction problem in which the convective heat flux at the cylinder surface was estimated by utilizing a measured temperature history inside the cylinder. An expression relating this coefficient to more general flame/cylinder systems was developed.

Three rhesus monkeys were trained to puff 1 of 2 tubes in order to obtain water. Cigarette smoke was delivered through one tube while air was delivered through the other. One of the monkeys showed a preference for the tube delivering air. Another monkey showed a preference for the tube delivering smoke. The third monkey showed no smoke or air preference. This technique therefore allowed smoking to be distinguished from puffing.