Calibrating and Stabilizing Spectropolarimeters with Charge Shuffling and Daytime Sky Measurements

Well-calibrated spectropolarimetry studies at resolutions of $R>$10,000 with signal-to-noise ratios (SNRs) better than 0.01\% across individual line profiles, are becoming common with larger aperture telescopes. Spectropolarimetric studies require high SNR observations and are often limited by instrument systematic errors. As an example, fiber-fed spectropolarimeters combined with advanced line-combination algorithms can reach statistical error limits of 0.001\% in measurements of spectral line profiles referenced to the continuum. Calibration of such observations is often required both for cross-talk and for continuum polarization. This is not straightforward since telescope cross-talk errors are rarely less than $\sim$1\%. In solar instruments like the Daniel K. Inouye Solar Telescope (DKIST), much more stringent calibration is required and the telescope optical design contains substantial intrinsic polarization artifacts. This paper describes some generally useful techniques we have applied to the HiVIS spectropolarimeter at the 3.7m AEOS telescope on Haleakala. HiVIS now yields accurate polarized spectral line profiles that are shot-noise limited to 0.01\% SNR levels at our full spectral resolution of 10,000 at spectral sampling of $\sim$100,000. We show line profiles with absolute spectropolarimetric calibration for cross-talk and continuum polarization in a system with polarization cross-talk levels of essentially 100\%. In these data the continuum polarization can be recovered to one percent accuracy because of synchronized charge-shuffling model now working with our CCD detector. These techniques can be applied to other spectropolarimeters on other telescopes for both night and day-time applications such as DKIST, TMT and ELT which have folded non-axially symmetric foci.Comment: Accepted to A&

Monetary benefits of preventing childhood lead poisoning with lead-safe window replacement

Previous estimates of childhood lead poisoning prevention benefits have quantified the present value of some health benefits, but not the costs of lead paint hazard control or the benefits associated with housing and energy markets. Because older housing with lead paint constitutes the main exposure source today in the U.S., we quantify health benefits, costs, market value benefits, energy savings, and net economic benefits of lead-safe window replacement (which includes paint stabilization and other measures). The benefit per resident child from improved lifetime earnings alone is $21,195 in pre-1940 housing and$8,685 in 1940-59 housing (in 2005 dollars). Annual energy savings are $130 to$486 per housing unit, with or without young resident children, with an associated increase in housing market value of $5,900 to$14,300 per housing unit, depending on home size and number of windows replaced. Net benefits are $4,490 to$5,629 for each housing unit built before 1940, and $491 to$1,629 for each unit built from 1940-1959, depending on home size and number of windows replaced. Lead-safe window replacement in all pre-1960 U.S. housing would yield net benefits of at least $67 billion, which does not include many other benefits. These other benefits, which are shown in this paper, include avoided Attention Deficit Hyperactivity Disorder, other medical costs of childhood lead exposure, avoided special education, and reduced crime and juvenile delinquency in later life. In addition, such a window replacement effort would reduce peak demand for electricity, carbon emissions from power plants, and associated long-term costs of climate change.Lead Poisoning, IQ, Energy Efficiency, Cost Benefit Analysis, Housing, Climate Change

Neurological and Behavioral Consequences of Childhood Lead Exposure

David Bellinger discusses two new cohort studies showing that childhood lead exposure is associated with brain volume reduction and criminal arrests in adulthood

Windows of opportunity: lead poisoning prevention, housing affordability, and energy conservation

We used housing demolition and window replacement rates to forecast prevalence trends for childhood lead poisoning and lead paint hazards from 1990 to 2010 for the President’s Task Force on Environmental Health Risks and Safety Risks to Children. The mid-point of that forecast has now been validated by national blood lead data and the 1998–2000 National Survey of Lead and Allergens in Housing. The validation of the task force model and new analysis of these survey data indicate that window replacement explains a large part of the substantial reduction in lead poisoning that occurred from 1990 to 2000. A public-private effort to increase window replacement rates could help eliminate childhood lead poisoning by 2010. This effort would also improve home energy efficiency and affordability, in addition to reducing air pollution from power plants, and a broader initiative could reduce other housing-related health risks as well

MEN 2A: Update on the Northern Ireland and Australian Family

The Northern Ireland/Australian family with multiple endocrine neoplasia type 2A (MEN 2A) originally described in 1987 is presented with a revised and enlarged pedigree. Four members of the first generation studied have died. A seventh member of the second generation studied has developed medullary thyroid carcinoma and has progressed to surgery. None of the third generation members studied has shown any conclusive abnormality in metabolic screening tests. Each member of the third and fourth generations has had genetic counseling and (if appropriate) DNA analysis with gene probes close to the MEN 2A gene locus on chromosome 10. All members of this highly penetrant family have remained asymptomatic for their disease

Windows of opportunity: lead poisoning prevention, housing affordability, and energy conservation

We used housing demolition and window replacement rates to forecast prevalence trends for childhood lead poisoning and lead paint hazards from 1990 to 2010 for the President’s Task Force on Environmental Health Risks and Safety Risks to Children. The mid-point of that forecast has now been validated by national blood lead data and the 1998–2000 National Survey of Lead and Allergens in Housing. The validation of the task force model and new analysis of these survey data indicate that window replacement explains a large part of the substantial reduction in lead poisoning that occurred from 1990 to 2000. A public-private effort to increase window replacement rates could help eliminate childhood lead poisoning by 2010. This effort would also improve home energy efficiency and affordability, in addition to reducing air pollution from power plants, and a broader initiative could reduce other housing-related health risks as well