Ammunition is the principal source of lead accumulated by California condors re-introduced to the wild

The endangered California Condor (Gymnogyps californianus) was reduced to a total population of 22 birds by the end of 1982. Their captive-bred descendants are now being released back into the wild in California, Arizona, and Baja California, where monitoring indicates they may accumulate lead to toxic levels. Fragments of ammunition in the carcasses of game animals such as deer, elk, and feral pigs not retrieved by hunters or in gut piles left in the field have been considered a plausible source of the lead, though little direct evidence is available to support this hypothesis. Here, we measured lead concentrations and isotope ratios in blood from 18 condors living in the wild in central California, in 8 pre-release birds, and in diet and ammunition samples to determine the importance of ammunition as a source of exposure. Blood lead levels in pre-release condors were low (average 27.7 ng/mL, SD 4.9 ng/ mL) and isotopically similar to dietary and background environmental lead in California. In contrast, blood lead levels in free-flying condors were substantially higher (average 246 ng/mL, SD 229 ng/mL) with lead isotopic compositions that approached or matched those of the lead ammunition. A two-endmember mixing model defined by the background 207Pb/206Pb ratio of representative condor diet samples (0.8346) and the upper 207Pb/206Pb ratio of the ammunition samples (0.8184) was able to account for the blood lead isotopic compositions in 20 out of the 26 live condors sampled in this study (i.e., 77%). Finally, lead in tissues and in a serially sampled growing feather recovered postmortem from a lead-poisoned condor in Arizona evidence acute exposure from an isotopically distinct lead source. Together, these data indicate that incidental ingestion of ammunition in carcasses of animals killed by hunters is the principal source of elevated lead exposure that threatens the recovery in the wild of this endangered species.     

Essential metalloelement chelates facilitate repair of radiation injury

Treatment with essential metalloelement (Cu, Fe, Mn, and Zn) chelates or combinations of them before and/or after radiation injury is a useful approach to overcoming radiation injury. No other agents are known to increase survival when they are used to treat after irradiation, in a radiorecovery treatment paradigm. These chelates may be useful in facilitating de novo syntheses of essential metalloelement-dependent enzymes required to repair radiation injury. Reports of radioprotection, which involves treatment before irradiation, with calcium-channel blockers, acyl Melatonin homologs, and substituted anilines, which may serve as chelating agents after biochemical modification in vivo, as well as Curcumin, which is a chelating agent, have been included in this review. These inclusions are intended to suggest additional approaches to combination treatments that may be useful in facilitating radiation recovery. These approaches to radioprotection and radiorecovery offer promise in facilitating recovery from radiation-induced injury experienced by patients undergoing radiotherapy for neoplastic disease and by individuals who experience environmental, occupational, or accidental exposure to ultraviolet, x-ray, or gamma-ray radiation. Since there are no existing treatments of radiation-injury intended to facilitate tissue repair, studies of essential metalloelement chelates and combinations of them, as well as combinations of them with existing organic radioprotectants, seem worthwhile.     

Asymmetric selection among organizations

We discuss the creation of organizations and their survivalas distinct selection processes, and consider the significanceof their divergence. In particular, to understand the implicationsof entrepreneurial booms, we propose the possibility of asymmetricselection, where entry selection and exit selection differ fromeach other in strength. An observed increase in founding rateshence may reveal a decline in the selection threshold for entry—implyinglower average fitness among boom-time entrants. When such anexpansion occurs, organizations born during these periods ofheightened entry should suffer higher failure rates if the fitnessthreshold required for survival remains stable or becomes morestringent. We also discuss other processes that might educefounding waves, and explain the different implications of theseaccounts for our empirical model. Estimates of the model supportour theory of asymmetric selection in two out of three marketsusing a comprehensive dataset describing organizations in theUS computer industry.     

Effects of vibration on the grain morphology

Pairs of halogen lamps were heated simultaneously at various rates of temperature increase through the recrystallization temperature and were held for five hours at 120 volts. One lamp in each of 20 pairs was vibrated during lightup. Examination of the grain boundaries of the filaments revealed that 63 pct of the boundaries in the vibrated lamps were “transverse.” In the lamps not vibrated, 52 pct of the boundaries were “transverse.” The greater number of “trans- verse” grain boundaries in the vibrated lamps is attributed to grain boundary sliding, which generates additional energy to allow the grain boundary to overcome the restraint to migration provided by the strings of potassium bubbles in the lamp wire. Formerly with GE Corporate Research and Formerly with GE Corporate Research and Formerly with the Technology Division, GE Lighting, Nela Park, Formerly with the Technology Division, GE Lighting, Nela Park,     

The PMSS approach to large-scale optimal control problems

Large-scale optimal control problems arise in several different contexts from a variety of applications. Many general computational algorithms have been proposed for the solution of these problems and a large literature on the subject abounds. To assimilate this material, it is necessary to overcome several difficulties. For example, the large-scale nature of the problems induces a complicated notation and specialized jargon that sometimes confuses the basic issues. Further, the ad hoc nature of the development of many algorithms tends to add an air of mystery that is difficult to dispel. Consequently, it is not always apparent that there are simple concepts and principles that underlie most, if not all, of these algorithms. In this paper, the general taxonomic scheme proposed by Geoffrion is exploited to provide a systematic framework for viewing computational algorithms for solving large-scale, optimal control problems. To demonstrate the utility of the viewpoint, a new algorithm for solving large-scale, discrete-time nonlinear optimal control problems is presented. The development is directed by the simple concepts and principles that underlie the proposed taxonomy.     

Localized 2D J-resolved 1H MR spectroscopy: strong coupling effects in vitro and in vivo

A two-dimensional (2D) J-resolved MR spectroscopy sequence (2D J-PRESS), fully localized in three dimensions, has been implemented on a whole-body MR scanner. A modified PRESS sequence with [90 degrees-180 degrees-t1/2-180 degrees-t1/2-acquisition] was used for voxel localization. An incremental delay (t1/2) was added to the intervals before and after the last slice-selective 180 degree RF pulse to monitor the J-evolution in a localized 2D MR spectrum. Spectra were recorded with phantoms containing common cerebral metabolites--alanine, N-acetyl aspartate, glutamine, glutamate, taurine, myo-inositol, glucose, aspartate, GABA, and choline at 50 mM. In conformity with previously reported results, additional cross-peaks due to strong coupling were monitored in many metabolites. A brain phantom was developed to mimic the gray matter of human brain with the metabolites at physiological concentrations (0.5-12 mM). In vivo 2D J-PRESS spectra (n = 18) of healthy human brain were in conformity with those recorded from the brain phantom.     

Moving targets: Patients' changing complaints during psychotherapy.

Used standardized assessment procedure recommended by J. Mintz (1977) to follow up 44 22–58 yr old patients in time-limited marital or family therapy in an investigation of Ss' changing complaints during psychotherapy. Ss were divided into 2 groups: those who were contacted for target-complaint assessment twice (Weeks 1 and 10) and those who were contacted 4 times (Weeks 1, 4, 7, and 10). At termination of treatment, Ss completed global outcome ratings on their success, satisfaction, and improvement with regard to target complaints. It was hyothesized that (1) S-rated improvement on new target complaints would significantly raise the multiple correlation with outcome criteria compared with initial complaints only and (2) the 2 interim measurements of target complaints would not constitute a therapeutic intervention (although previous researchers have contended that defining target symptoms is therapeutic in itself). Results support the hypotheses. ANOVA revealed that membership in either the 2- or 4-contact assessment group was unrelated to the pooled global outcome rating. Across treatment, 56% of Ss listed new target complaints in addition to those mentioned at Week 1. S-rated improvement on these new issues accounted for a significant increment in outcome variance and was the single best predictor of therapy outcome. Findings are discussed in terms of implications for comparative-competitive psychotherapy studies and process and outcome research. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On determining if a specular point exists

A technique is presented whereby the existence of a specular point on a convex surface of revolution can be determined without actually finding it. Only the evaluation of two simple algebraic expressions is involved. Should a specular point be found not to exist, a search procedure has been thereby eliminated.     

Variable dual-frequency electrostatic wave launcher for plasma applications

A variable tuning system is presented for launching two electrostatic waves concurrently in a magnetized plasma. The purpose of this system is to satisfy the wave launching requirements for plasma applications where maximal power must be coupled into two carefully tuned electrostatic waves while minimizing erosion to the launching antenna. Two parallel LC traps with fixed inductors and variable capacitors are used to provide an impedance match between a two-wave source and a loop antenna placed outside the plasma. Equivalent circuit analysis is then employed to derive an analytical expression for the normalized, average magnetic flux density produced by the antenna in this system as a function of capacitance and frequency. It is found with this metric that the wave launcher can couple to electrostatic modes at two variable frequencies concurrently while attenuating noise from the source signal at undesired frequencies. An example based on an experiment for plasma heating with two electrostatic waves is used to demonstrate a procedure for tailoring the wave launcher to accommodate the frequency range and flux densities of a specific two-wave application. This example is also used to illustrate a method based on averaging over wave frequencies for evaluating the overall efficacy of the system. The wave launcher is shown to be particularly effective for the illustrative example--generating magnetic flux densities in excess of 50% of the ideal case at two variable frequencies concurrently--with a high adaptability to a number of plasma dynamics and heating applications.     

A randomized sublinear time parallel GCD algorithm for the EREW PRAM

We present a randomized parallel algorithm that computes the greatest common divisor of two integers of n bits in length with probability 1−o(1) that takes O(nloglogn/logn) time using O(n6+?) processors for any ?>0 on the EREW PRAM parallel model of computation. The algorithm either gives a correct answer or reports failure.We believe this to be the first randomized sublinear time algorithm on the EREW PRAM for this problem.