Considerable disparities in cancer survival rates exist between African Americans (AAs) and white Americans (WAs). Various factors such as differences in socioeconomic status (SES), cancer stage at time of diagnosis, and treatment - which this analysis considers primary explanatory factors - have accounted for many of these differences. An additional factor not usually considered is vitamin D. Previous studies have inversely correlated higher solar ultraviolet-B (UVB) doses and serum 25-hydroxyvitamin D (25(OH)D) concentrations with incidence and/or mortality rates for about 20 types of cancer and improved survival rates for eight types of cancer. Because of darker skin pigmentation, AAs have 40% lower serum 25(OH)D concentrations than WAs. This study reviews the literature on disparities in cancer survival between AAs and WAs. The journal literature indicates that there are disparities for 13 types of cancer after consideration of SES, stage at diagnosis and treatment: bladder, breast, colon, endometrial, lung, ovarian, pancreatic, prostate, rectal, testicular, and vaginal cancer; Hodgkin lymphoma and melanoma. Solar UVB doses and/or serum 25(OH)D concentrations have been reported inversely correlated with incidence and/or mortality rates for all of these cancers. This finding suggests that future studies should consider serum 25(OH)D concentrations in addressing cancer survival disparities through both measurements of serum 25(OH)D concentrations and increasing serum 25(OH)D concentrations of those diagnosed with cancer, leading to improved survival rates and reduced disparities.

The B0.2 V magnetic star τ Sco stands out from the larger population of massive magnetic OB stars due to its remarkable, superionized wind, apparently related to its peculiar magnetic field - a field which is far more complex than the mostly-dipolar fields usually observed in magnetic OB stars. τ Sco is therefore a puzzling outlier in the larger picture of stellar magnetism - a star that still defies interpretation in terms of a physically coherent model. Recently, two early B-type stars were discovered as τ Sco analogues, identified by the striking similarity of their UV spectra to that of τ Sco, which was - until now - unique among OB stars. We present the recent detection of their magnetic fields by the MiMeS collaboration, reinforcing the connection between the presence of a magnetic field and a superionized wind. We will also present ongoing observational efforts undertaken to establish the precise magnetic topology, in order to provide additional constrains for existing models attempting to reproduce the unique wind structure of τ Sco-like stars.

We have used the Hubble STIS and FUSE archives of ultraviolet spectra of bright AGNs to identify intergalactic Lya absorbers in nearby (z ≤ 0.1) voids. From a parent sample of 651 Lyα absorbers, we identified 61 "void absorbers" located >1.4 h70-1 Mpc from the nearest L* or brighter galaxy. Searching for metal absorption in high-quality (S/N > 10) spectra at the location of three diagnostic metal lines (O VI λ1032, C IV λ1548, Si III λ1206), we detected no metal lines in any individual absorber, or in any group of absorbers using pixel co-addition techniques. The best limits on metal-line absorption in voids were set using four strong Lya absorbers with NHI > 1014 cm-2, with 3 σ equivalent-width limits ranging from 8 mÅ (O VI) to 7-15 mÅ (C IV) and 4-10 mÅ (Si III). Photoionization modeling yields metallicity limits Z < 10 -1.8±0.4 Z⊙ from nondetections of C IV and VI, some ∼6 times lower than those seen in Lyα/O VI absorbers at z < 0.1. Although the void Lyα absorbers could be pristine material, considerably deeper spectra are required to rule out a universal metallicity floor produced by bursts of early star formation, with no subsequent star formation in the voids. The most consistent conclusion derived from these low-z results and similar searches at z = 3-5 is that galaxy filaments have increased their mean IGM metallicity by factors of 30-100 since z ∼ 3.

We report the discovery of a dwarf (MB = -13.9) poststarburst galaxy coincident in recession velocity (within uncertainties) with the highest column density absorber (NHI = 1015.85 cm-2 at cz = 1586 km s-1) in the 3C 273 sight line. This galaxy is by far the closest galaxy to this absorber, projected just 71 h70-1 kpc on the sky from the sight line. The mean properties of the stellar populations in this galaxy are consistent with a massive starburst ≈3.5 Gyr ago, whose attendant supernovae, we argue, could have driven sufficient gas from this galaxy to explain the nearby absorber. Beyond its proximity on the sky and in recession velocity, the further evidence in favor of this conclusion includes both a match in the metallicities of absorber and galaxy and the fact that the absorber has an overabundance of Si/C, suggesting recent Type II supernova enrichment. Thus, this galaxy and its ejecta are in the expected intermediate stage in the fading dwarf evolutionary sequence envisioned by Babul & Rees to explain the abundance of faint blue galaxies at intermediate redshifts. While this one instance of a QSO metal-line absorber and a nearby dwarf galaxy is not proof of a trend, a similar dwarf galaxy would be too faint to be observed by galaxy surveys around more distant metal-line absorbers. Thus, we cannot exclude the possibility that dwarf galaxies are primarily responsible for weak (NHI = 1014-1017 cm-2) metal-line absorption systems in general. If a large fraction of the dwarf galaxies expected to exist at high redshift had a similar history (i.e., they had a massive starburst that removed all or most of their gas), these galaxies could account for at least several hundred high-z metal-line absorbers along the line of sight to a high-z QSO. The volume-filling factor for this gas, however, would be less than 1%.

We obtained high-resolution Far Ultraviolet Spectroscopic Explorer (FUSE; R ∼ 20,000) and Very Large Telescope (VLT; R ∼ 45,000) spectra of the quasar HE 2347-4342 in order to study the properties of the intergalactic medium between redshifts z = 2.0 and 2.9. The high-quality optical spectrum allows us to identify approximately 850 H I absorption lines with column densities between N ∼ 5×1011 and 1018 cm-2. The reprocessed FUSE spectrum extends the wavelength coverage of the He II absorption down to an observed wavelength of 920 Å. Source flux is detected to rest-frame wavelengths as short as ∼237 Å. Approximately 1400 He II absorption lines are identified, including 917 He II Lyα systems and some of their He II Lyβ, Lyγ, and Lyδ counterparts. The ionization structure of He II is complex, with approximately 90 absorption lines that are not detected in the hydrogen spectrum. These features may represent the effect of soft ionizing sources. The ratio η = N(He II)/N(H I) varies approximately from unity to more than a thousand, with a median value of 62 and a distribution consistent with the intrinsic spectral indexes of quasars. This provides evidence that the dominant ionizing field is from the accumulated quasar radiation, with contributions from other soft sources such as star-forming regions and obscured active galactic nuclei, which do not ionize helium. We find an evolution in η toward smaller values at lower redshift, with the gradual disappearance of soft components. At redshifts z > 2.7, the large but finite increase in the He II opacity, τ = 5 ± 1, suggests that we are viewing the end stages of a reionization process that began at an earlier epoch. Fits of the absorption profiles of unblended lines indicate comparable velocities between hydrogen and He+ ions. For line widths bHe+He+ = ξbH, we find ξ = 0.95 ± 0.12, indicating a velocity field in the intergalactic medium dominated by turbulence. At hydrogen column densities N < 3 × 1012 cm-2, the number of forest lines shows a significant deficit relative to a power law and becomes negligible below N = 1011 cm-2.

To gain insight into four highly ionized high-velocity clouds (HVCs) discovered by Sembach et al., we have analyzed data from the Hubble Space Telescope (HST) and Far Ultraviolet Spectroscopic Explorer (FUSE) for the PKS 2155-304 and Mrk 509 sight lines. We measure strong absorption in O VI and column densities of multiple ionization stages of silicon (Si II, III, and IV) and carbon (C II, III, and IV). We interpret this ionization pattern as a multiphase medium that contains both collisionally ionized and photoionized gas. Toward PKS 2155-304, for HVCs at -140 and -270 km s-1, respectively, we measure logN(O VI) = 13.80 ± 0.03 and logN(O VI) = 13.56 ± 0.06; from Lyman series absorption, we find logN(H I) = 16.37 -0.14+0.22 and 15.23-0.22+0.38. The presence of high-velocity O VI spread over a broad (100 km s-1) profile, together with large amounts of low-ionization species, is difficult to reconcile with the low densities, ne ≈ 5 × 10-6 cm-3, in the collisional/photoionization models of Nicastro et al., although the HVCs show a similar relation in N(Si IV)/N(C IV) versus N(C II)/N(C IV) to that of high-z intergalactic clouds. Our results suggest that the high-velocity O VI in these absorbers does not necessarily trace the warm-hot intergalactic medium but instead may trace HVCs with low total hydrogen column density. We propose that the broad high-velocity O VI absorption arises from shock ionization, at bow shock interfaces produced from infalling clumps of gas with velocity shear. The similar ratios of high ions for HVC Complex C and these highly ionized HVCs suggest a common production mechanism in the Galactic halo.

We present new, contemporaneous Hubble Space Telescope STIS and XMM-Newton observations of the O7 III(n)((f)) star ξ Per. We supplement the new data with archival IUE spectra, to analyze the variability of the wind lines and X-ray flux of ξ Per. The variable wind of this star is known to have a 2.086-day periodicity. We use a simple, heuristic spot model that fits the low-velocity (near-surface) IUE wind line variability very well, to demonstrate that the low-velocity absorption in the new STIS spectra of N iv λ1718 and Si iv λ1402 vary with the same 2.086-day period. It is remarkable that the period and amplitude of the STIS data agree with those of the IUE spectra obtained 22 yr earlier. We also show that the time variability of the new XMM-Newton fluxes is also consistent with the 2.086-day period. Thus, our new, multiwavelength coordinated observations demonstrate that the mechanism that causes the UV wind line variability is also responsible for a significant fraction of the X-rays in single O stars. The sequence of events for the multiwavelength light-curve minima is Si iv λ1402, N iv λ1718, and X-ray flux, each separated by a phase of about 0.06 relative to the 2.086-day period. Analysis of the X-ray fluxes shows that they become softer as they weaken. This is contrary to expectations if the variability is caused by periodic excess absorption. Furthermore, the high-resolution X-ray spectra suggest that the individual emission lines at maximum are more strongly blueshifted. If we interpret the low-velocity wind line light curves in terms of our model, it implies that there are two bright regions, i.e., regions with less absorption, separated by 180°, on the surface of the star. We note that the presence and persistence of two spots separated by 180° suggest that a weak dipole magnetic field is responsible for the variability of the UV wind line absorption and X-ray flux in ξ Per.

Given the prevalence and risk associated with indoor tanning among college students, university campuses constitute a prime target for skin cancer prevention. This report identifies the successes and challenges faced in promoting a campus-wide tan-free policy through the National Council on Skin Cancer Prevention (NCSCP) Indoor Tan-Free Skin Smart Campus Initiative. Beginning in February 2016, we communicated with university faculty or staff members who have participated in skin cancer prevention via education, clinical care, or research at 20 universities regarding the steps to adopt the tan-free policy. One campus, East Tennessee State University (ETSU), successfully fulfilled all criteria and implemented the policy change to become the first US Indoor Tan-Free Skin Smart Campus. The greatest challenge faced in recruiting campuses was gaining administrative support. Reported reasons for not adopting the policy change included wanting to wait for other schools to join first and not seeing it as a top priority. Despite the importance of improving skin cancer awareness and decreasing tanning among university students, we faced several challenges in promoting campus-wide policy change. We identify a need for research on effective ways to disseminate university health policies and increased involvement of healthcare providers in policy-related work.

The majority of ancient people worshipped the sun and viewed it as a health - bringing deity. During the eighteenth and nineteenth century therapeutic benefits of sunlight exposure were beginning to be understood and by the end of the nineteenth century the importance of ultraviolet radiation was being realized. Danish physician Niels Finsen, whom many regard as the father of ultraviolet phototherapy, also stressed that it was ultraviolet radiation in the solar spectrum which cause sunburn. We now recognize that the small portion of ultraviolet radiation which reaches the earth's surface is not necessarily therapeutic, but in fact could be harmful to humans. There are numerous accounts of the harmful effects of UV radiation to the skin and the eye as a whole. These effects may be caused by either acute or chronic exposure to UV radiation. For example, some acute effects of UV-B radiation include conjunctivitis and photokeratitis. "Snow blindness" and "arc welders eye" are further examples of acute ultraviolet damage specifically to the surface of the cornea. On the other hand, chronic exposure to ultraviolet radiation is thought to be responsible for pterygia, climatic droplet keratopathy Hill and Maske (1989), cancers of the external eye, cataracts and various types of retinal diseases. The present study is an extension of ongoing studies on ultraviolet radiation damage to the cornea in the Department of Ophthalmology, University of Cape Town and Groote Schuur Hospital. Their specific interest lies in the causes and treatment of climatic droplet keratopathy. The aims of the present study are: 1) Establish a possible role of ultraviolet B radiation in human corneal diseases such as climatic droplet keratopathy and pterygium using the rabbit as an animal model. 2) Determine by means of SEM the initial effects and subsequent recovery of the epithelium after a 3-hour dose of ultraviolet B radiation. We refer to this study as "acute" response to ultraviolet B radiation. 3) To try and confirm the effects observed by SEM with ultrastructural studies using TEM. 4) In addition, we are also looking at the possible effects after exposing rabbit cornea to a daily dose of low level ultraviolet B radiation, over a long period of time. We refer to this as chronic exposure to ultraviolet B radiation. It is hoped that by exposing rabbits to ultraviolet light, principally ultraviolet B radiation, diseases similar to those found in humans could be simulated and disease progression studied. People are generally exposed to substantial amounts of UV radiation for a very long time. Since people generally live longer they will be exposed to an ever-increasing amount of solar UV radiation and subsequently, there is an increasing risk of developing corneal diseases. The possible threat to the ozone is also a real possibility and could lead to increased levels of ultraviolet radiation reaching the earth's surface. This will require a greater understanding of the very nature of corneal damage due to acute and chronic exposure. This study focusses mainly on the acute response to UV-B radiation since most studies have investigated effects of prolonged exposure to UV light. Accordingly, much less is known about acute exposure. Many people suffering from acute UV B radiation effects probably never visit the ophthalmologist or wait for a couple of days. This could also contribute to the fact that effects of short-term damage is not well documented.

For the past several decades, challenges in the detection and collection of latent prints exposed to harsh environmental conditions have inspired research in pretreatment methods prior to the application of chemical, physical, or optical-based enhancement techniques. Some of the difficulties associated with processing degraded latent prints are attributed to dehydration, alterations in chemical composition, and physical disturbance of ridge detail. This study seeks to investigate the effectiveness of humidity, cyanoacrylate fuming method (CFM), and a reflected ultraviolet imaging system (RUVIS) on the detection and collection of aged latent palmprints. Prints were exposed to air flow and ultraviolet (UV) light for a period of 0 to 28 days, and subsequently treated with either cool or warm humidity and CFM. RUVIS was then utilized to detect and capture friction ridge detail after each treatment step. Improvements in RUVIS detection between treatments were evaluated based on four response factors: minutiae count, percent print recovery, ridge thickness and contrast. By measuring these factors, each latent print photograph was able to be converted to quantifiable data to facilitate statistical analysis of potential differences or improvements between treatments. The results demonstrate that the application of 80% relative humidity successfully revived aged latent palmprints across all factors. The combined effect of humidity followed v by CFM treatment and RUVIS detection was greatest for minutiae count and ridge thickness, while percent print recovery and contrast demonstrated more modest improvements when compared to control prints. Additionally, cool temperature treatments outperformed warm temperature treatments across all factors except contrast. The data therefore suggest that to achieve print rejuvenation and overall improvements in RUVIS detection, combined cool humidity and CFM is more effective than humidity alone. The data also indicate a potential correlation between temperature treatments and latent print age. Warm humidity combined with CFM appeared to best enhance RUVIS images on fresher prints of a few days to one week old, while cool humidity and CFM appeared to maximally enhance RUVIS images on prints of several weeks old.