Bronston and Burnside Members: Subdivision of the St. Louis Limestone in South-Central Kentucky

The St. Louis Limestone (Mississippian) of south-central Kentucky consists of two major lithologic units that herein are named, in ascending order, the Bronston Member and Burnside Member. Two other lithologic units occurring in the St. Louis Limestone and in correlative rocks of the Slade Formation (Mississippian), which extends from south-central into northeastern Kentucky, herein are named the Ringgold Bed and Big Sinking Bed. The principal part of the St. Louis Member of the Slade Formation, which consists of Burnside lithologies, herein is renamed the Burnside Member of the Slade. This renaming addresses the problem associated with the previous use of the name St. Louis for both a formation and a member that is only partly correlative with the formation

Low-Silica and High-Calcium Stone in the Newman Limestone (Mississippian) on Pine Mountain, Harlan County, Southeastern Kentucky

The coal industry of Kentucky is an important market for limestone. Coal producers use limestone as rock dust for explosion abatement in underground coal mines and as a neutralizing agent in surface-mine reclamation and acid-drainage control. Crushed stone is also used for constructing and maintaining haulage roads. In the Eastern Kentucky Coal Field, the coal-bearing rocks of Pennsylvanian age generally do not contain limestones that are thick enough to quarry or mine economically. But movement on the Pine Mountain overthrust fault has brought the Newman Limestone (Mississippian) to the surface along Pine Mountain in the southeastern part of the coal field. The Newman on Pine Mountain in Harlan County was sampled at 1-foot intervals to determine its chemical quality and potential for industrial use, particular as low-silica rock dust. The sampled section contains two zones of low-silica stone, 64 and 25 feet thick, averaging 0.82 and 1.01 percent silica (SiO2), respectively. Intervals of high-calcium limestone are present in the low-silica zones. These deposits are potentially suitable for use as rock dust in underground coal mines and as neutralizing agents in surface-mine reclamation and acid-drainage control. The intervals of chemically pure stone in Harlan County may be sufficiently thick to produce by selective quarrying or underground mining. Exploitation of the Newman deposits, however, will be complicated by the steep southeastward to southward dip (13 to 42°) of the beds, displacement along small faults within the limestone, and fracturing

Intercontinental transport of pollution manifested in the variability and seasonal trend of springtime O3 at northern middle and high latitudes

Observations (0–8 km) from the Tropospheric Ozone Production about the Spring Equinox (TOPSE) experiment are analyzed to examine air masses contributing to the observed variability of springtime O3 and its seasonal increase at 40°–85°N over North America. Factor analysis using the positive matrix factorization and principal component analysis methods is applied to the data set with 14 chemical tracers (O3, NOy, PAN, CO, CH4, C2H2, C3H8, CH3Cl, CH3Br, C2Cl4, CFC-11, HCFC-141B, Halon-1211, and 7Be) and one dynamic tracer (potential temperature). Our analysis results are biased by the measurements at 5–8 km (70% of the data) due to the availability of 7Be measurements. The identified tracer characteristics for seven factors are generally consistent with the geographical origins derived from their 10 day back trajectories. Stratospherically influenced air accounts for 14 ppbv (35–40%) of the observed O3 variability for data with O3concentrations \u3c100 ppbv at middle and high latitudes. It accounts for about 2.5 ppbv/month (40%) of the seasonal O3 trend at midlatitudes but for only 0.8 ppbv/month (\u3c20%) at high latitudes, likely reflecting more vigorous midlatitude dynamical systems in spring. At midlatitudes, reactive nitrogen-rich air masses transported through Asia are much more significant (11 ppbv in variability and 3.5 ppbv/month in trend) than other tropospheric contributors. At high latitudes the O3 variability is significantly influenced by air masses transported from lower latitudes (11 ppbv), which are poor in reactive nitrogen. The O3 trend, in contrast, is largely defined by air masses rich in reactive nitrogen transported through Asia and Europe across the Pacific or the Arctic (3 ppbv/month). The influence from the stratospheric source is more apparent at 6–8 km, while the effect of O3 production and transport within the troposphere is more apparent at lower altitudes. The overall effect of tropospheric photochemical production, through long-range transport, on the observed O3 variability and its seasonal trend is more important at high latitudes relative to more photochemically active midlatitudes

Low-Silica and High-Calcium Stone in the Newman Limestone (Mississippian) on Pine Mountain, Letcher County, Southeastern Kentucky

The coal industry of Kentucky is an important market for limestone. Coal producers use limestone as rock dust for explosion abatement in underground coal mines and as a neutralizing agent in surface-mine reclamation and acid-drainage control. Haulage-road construction and maintenance require crushed stone. Coal-bearing rocks of Pennsylvanian age in the Eastern Kentucky Coal Field generally do not contain limestones that are sufficiently thick to quarry or mine economically, but in the southeastern part of the coal field, fault movement has brought the Newman Limestone to the surface along Pine Mountain. The Newman was sampled at three sites in Letcher County to determine its chemical quality and potential for industrial use, particularly as a source of low-silica rock dust. Analysis of the foot-by-foot samples shows that the Newman contains several zones of low-silica stone, 10 to 39 feet thick. A few intervals of high-calcium limestone, 12 to 24 feet thick, coincide with or occur in the low-silica zones. The deposits of low-silica and high-calcium stone are thickest in the southwestern part of Letcher County and commonly thin northeastward. The thicker deposits of chemically pure limestone and dolomite may be an economically exploitable source of rock dust for underground coal mines, and a source of stone for surface-mine reclamation and acid-drainage control. Production from deposits in the Newman, however, will be complicated by the steep southeastward to southward dip (20 to 42°) of the beds, possible displacement along small faults, and fracturing of the limestone

Ozone depletion events observed in the high latitude surface layer during the TOPSE aircraft program

During the Tropospheric Ozone Production about the Spring Equinox (TOPSE) aircraft program, ozone depletion events (ODEs) in the high latitude surface layer were investigated using lidar and in situ instruments. Flight legs of 100 km or longer distance were flown 32 times at 30 m altitude over a variety of regions north of 58° between early February and late May 2000. ODEs were found on each flight over the Arctic Ocean but their occurrence was rare at more southern latitudes. However, large area events with depletion to over 2 km altitude in one case were found as far south as Baffin Bay and Hudson Bay and as late as 22 May. There is good evidence that these more southern events did not form in situ but were the result of export of ozone-depleted air from the surface layer of the Arctic Ocean. Surprisingly, relatively intact transport of ODEs occurred over distances of 900–2000 km and in some cases over rough terrain. Accumulation of constituents in the frozen surface over the dark winter period cannot be a strong prerequisite of ozone depletion since latitudes south of the Arctic Ocean would also experience a long dark period. Some process unique to the Arctic Ocean surface or its coastal regions remains unidentified for the release of ozone-depleting halogens. There was no correspondence between coarse surface features such as solid ice/snow, open leads, or polynyas with the occurrence of or intensity of ozone depletion over the Arctic or subarctic regions. Depletion events also occurred in the absence of long-range transport of relatively fresh “pollution” within the high latitude surface layer, at least in spring 2000. Direct measurements of halogen radicals were not made. However, the flights do provide detailed information on the vertical structure of the surface layer and, during the constant 30 m altitude legs, measurements of a variety of constituents including hydroxyl and peroxy radicals. A summary of the behavior of these constituents is made. The measurements were consistent with a source of formaldehyde from the snow/ice surface. Median NOx in the surface layer was 15 pptv or less, suggesting that surface emissions were substantially converted to reservoir constituents by 30 m altitude and that ozone production rates were small (0.15–1.5 ppbv/d) at this altitude. Peroxyacetylnitrate (PAN) was by far the major constituent of NOy in the surface layer independent of the ozone mixing ratio

Microstructural evolution and transmutation in tungsten under ion and neutron irradiation

This study aims to compare the effects of neutron and self-ion irradiation on the mechanical properties and microstructural evolution in W. Neutron irradiation at the HFR reactor to 1.67 dpa at 800 °C resulted in the formation of large Re and Os rich clusters and voids. The post-irradiation composition was measured using APT and verfified against FISPACT modelling. The measured Re and Os concentration was used to create alloys with equivalent concentrations of Re and Os. These alloys were exposed to self-ion irradiation to a peak dose of 1.7 dpa at 800 °C. APT showed that self-ion irradiation leads to the formation of small Os clusters, wheras under neutron irradiation large Re/Os clusters form. Voids are formed by both ion and neutron irradiation, but the voids formed by neutron irradiation are larger. By comparing the behaviour of W-1.4Re and W-1.4Re-0.1Os, suppression of Re cluster formation was observed. Irradiation hardening was measured using nanoindentation and was found to be 2.7 GPa, after neutron irradiation and 1.6 GPa and 0.6 GPa for the self-ion irradiated W-1.4Re and W-1.4Re-0.1Os. The higher hardening is attributed to the barrier strength of large voids and Re/Os clusters that are observed after neutron irradiation

Cardiovascular risk scoring and magnetic resonance imaging detected subclinical cerebrovascular disease

AIMS: Cardiovascular risk factors are used for risk stratification in primary prevention. We sought to determine if simple cardiac risk scores are associated with magnetic resonance imaging (MRI)-detected subclinical cerebrovascular disease including carotid wall volume (CWV), carotid intraplaque haemorrhage (IPH), and silent brain infarction (SBI). METHODS AND RESULTS: A total of 7594 adults with no history of cardiovascular disease (CVD) underwent risk factor assessment and a non-contrast enhanced MRI of the carotid arteries and brain using a standardized protocol in a population-based cohort recruited between 2014 and 2018. The non-lab-based INTERHEART risk score (IHRS) was calculated in all participants; the Framingham Risk Score was calculated in a subset who provided blood samples (n = 3889). The association between these risk scores and MRI measures of CWV, carotid IPH, and SBI was determined. The mean age of the cohort was 58 (8.9) years, 55% were women. Each 5-point increase (∼1 SD) in the IHRS was associated with a 9 mm3 increase in CWV, adjusted for sex (P \u3c 0.0001), a 23% increase in IPH [95% confidence interval (CI) 9-38%], and a 32% (95% CI 20-45%) increase in SBI. These associations were consistent for lacunar and non-lacunar brain infarction. The Framingham Risk Score was also significantly associated with CWV, IPH, and SBI. CWV was additive and independent to the risk scores in its association with IPH and SBI. CONCLUSION: Simple cardiovascular risk scores are significantly associated with the presence of MRI-detected subclinical cerebrovascular disease, including CWV, IPH, and SBI in an adult population without known clinical CVD

Human Papillomaviruses Activate the ATM DNA Damage Pathway for Viral Genome Amplification upon Differentiation

Human papillomaviruses (HPV) are the causative agents of cervical cancers. The infectious HPV life cycle is closely linked to the differentiation state of the host epithelia, with viral genome amplification, late gene expression and virion production restricted to suprabasal cells. The E6 and E7 proteins provide an environment conducive to DNA synthesis upon differentiation, but little is known concerning the mechanisms that regulate productive viral genome amplification. Using keratinocytes that stably maintain HPV-31 episomes, and chemical inhibitors, we demonstrate that viral proteins activate the ATM DNA damage response in differentiating cells, as indicated by phosphorylation of CHK2, BRCA1 and NBS1. This activation is necessary for viral genome amplification, as well as for formation of viral replication foci. In contrast, inhibition of ATM kinase activity in undifferentiated keratinocytes had no effect on the stable maintenance of viral genomes. Previous studies have shown that HPVs induce low levels of caspase 3/7 activation upon differentiation and that this is important for cleavage of the E1 replication protein and genome amplification. Our studies demonstrate that caspase cleavage is induced upon differentiation of HPV positive cells through the action of the DNA damage protein kinase CHK2, which may be activated as a result of E7 binding to the ATM kinase. These findings identify a major regulatory mechanism responsible for productive HPV replication in differentiating cells. Our results have potential implications for the development of anti-viral therapies to treat HPV infections

Activation of Host Translational Control Pathways by a Viral Developmental Switch

In response to numerous signals, latent herpesvirus genomes abruptly switch their developmental program, aborting stable host–cell colonization in favor of productive viral replication that ultimately destroys the cell. To achieve a rapid gene expression transition, newly minted capped, polyadenylated viral mRNAs must engage and reprogram the cellular translational apparatus. While transcriptional responses of viral genomes undergoing lytic reactivation have been amply documented, roles for cellular translational control pathways in enabling the latent-lytic switch have not been described. Using PEL-derived B-cells naturally infected with KSHV as a model, we define efficient reactivation conditions and demonstrate that reactivation substantially changes the protein synthesis profile. New polypeptide synthesis correlates with 4E-BP1 translational repressor inactivation, nuclear PABP accumulation, eIF4F assembly, and phosphorylation of the cap-binding protein eIF4E by Mnk1. Significantly, inhibiting Mnk1 reduces accumulation of the critical viral transactivator RTA through a post-transcriptional mechanism, limiting downstream lytic protein production, and impairs reactivation efficiency. Thus, herpesvirus reactivation from latency activates the host cap-dependent translation machinery, illustrating the importance of translational regulation in implementing new developmental instructions that drastically alter cell fate