Paleoindian Predictive Model for Yellowstone National Park

The Greater Yellowstone Region was a destination for nomadic hunter-gatherers for at least 12,000 years. Archaeological sites representing the whole spectrum of time, cultures, and activities, have been found throughout the region. Within Yellowstone National Park a number of Paleoindian projectile points and other related cultural materials have been recorded, however, only a handful of buried Paleoindian sites have been identified and excavated. Considering the nature of the archaeological record in the area, some interesting questions surface about the value of the information recorded on the Paleoindian sites. In terms of Yellowstone National Park (YNP) Paleoindian archaeology, is it possible to use the existing Paleoindian sites to make inferences about the landscape choices of Paleoindian cultures? Can the relationship between the location of known Paleoindian sites and the environment be modeled using quantitative methods? If so, is it possible to use the information about land use patterns derived from a known set of sites to find additional, currently unknown, Paleoindian sites? This paper attempts to answer those questions through the development of an archaeological predictive model, focused on Paleoindian sites, for Yellowstone National Park. Utilizing Geographic Information Systems (GIS) and statistical software, a probability model has been created that relates the existence or nonexistence of Paleoindian cultural materials with sixteen selected environmental features. The model output classifies areas within YNP through a set of environmental characteristics favorable for finding Paleoindian cultural material

Nodal Liquid Theory of the Pseudo-Gap Phase of High-Tc Superconductors

We introduce and study the nodal liquid, a novel zero-temperature quantum phase obtained by quantum-disordering a d-wave superconductor. It has numerous remarkable properties which lead us to suggest it as an explanation of the pseudo-gap state in underdoped high-temperature superconductors. In the absence of impurities, these include power-law magnetic order, a T-linear spin susceptibility, non-trivial thermal conductivity, and two- and one-particle charge gaps, the latter evidenced, e.g. in transport and electron photoemission (which exhibits pronounced fourfold anisotropy inherited from the d-wave quasiparticles). We use a 2+1-dimensional duality transformation to derive an effective field theory for this phase. The theory is comprised of gapless neutral Dirac particles living at the former d-wave nodes, weakly coupled to the fluctuating gauge field of a dual Ginzburg-Landau theory. The nodal liquid interpolates naturally between the d-wave superconductor and the insulating antiferromagnet, and our effective field theory is powerful enough to permit a detailed analysis of a panoply of interesting phenomena, including charge ordering, antiferromagnetism, and d-wave superconductivity. We also discuss the zero-temperature quantum phase transitions which separate the nodal liquid from various ordered phases.Comment: 19 pages, 4 figure

Effect of Vascepa (icosapent ethyl) on progression of coronary atherosclerosis in patients with elevated triglycerides (200-499 mg/dL) on statin therapy: Rationale and design of the EVAPORATE study.

Despite reducing progression and promoting regression of coronary atherosclerosis, statin therapy does not fully address residual cardiovascular (CV) risk. High-purity eicosapentaenoic acid (EPA) added to a statin has been shown to reduce CV events and induce regression of coronary atherosclerosis in imaging studies; however, data are from Japanese populations without high triglyceride (TG) levels and baseline EPA serum levels greater than those in North American populations. Icosapent ethyl is a high-purity prescription EPA ethyl ester approved at 4 g/d as an adjunct to diet to reduce TG levels in adults with TG levels >499 mg/dL. The objective of the randomized, double-blind, placebo-controlled EVAPORATE study is to evaluate the effects of icosapent ethyl 4 g/d on atherosclerotic plaque in a North American population of statin-treated patients with coronary atherosclerosis, TG levels of 200 to 499 mg/dL, and low-density lipoprotein cholesterol levels of 40 to 115 mg/dL. The primary endpoint is change in low-attenuation plaque volume measured by multidetector computed tomography angiography. Secondary endpoints include incident plaque rates; quantitative changes in different plaque types and morphology; changes in markers of inflammation, lipids, and lipoproteins; and the relationship between these changes and plaque burden and/or plaque vulnerability. Approximately 80 patients will be followed for 9 to 18 months. The clinical implications of icosapent ethyl 4 g/d treatment added to statin therapy on CV endpoints are being evaluated in the large CV outcomes study REDUCE-IT. EVAPORATE will provide important imaging-derived data that may add relevance to the clinically derived outcomes from REDUCE-IT

Exploring the Chemical Composition and Double Horizontal Branch of the Bulge Globular Cluster NGC 6569

Photometric and spectroscopic analyses have shown that the Galactic bulge cluster Terzan 5 hosts several populations with different metallicities and ages that manifest as a double red horizontal branch (HB). A recent investigation of the massive bulge cluster NGC 6569 revealed a similar, though less extended, HB luminosity split, but little is known about the cluster's detailed chemical composition. Therefore, we have used high-resolution spectra from the Magellan-M2FS and VLT-FLAMES spectrographs to investigate the chemical compositions and radial velocity distributions of red giant branch and HB stars in NGC 6569. We found the cluster to have a mean heliocentric radial velocity of -48.8 km/s (sigma = 5.3 km/s; 148 stars) and a mean [Fe/H] =-0.87 dex (19 stars), but the cluster's 0.05 dex [Fe/H] dispersion precludes a significant metallicity spread. NGC 6569 exhibits light- and heavy-element distributions that are common among old bulge/inner Galaxy globular clusters, including clear (anti)correlations between [O/Fe], [Na/Fe], and [Al/Fe]. The light-element data suggest that NGC 6569 may be composed of at least two distinct populations, and the cluster's low mean [La/Eu] = -0.11 dex indicates significant pollution with r-process material. We confirm that both HBs contain cluster members, but metallicity and light-element variations are largely ruled out as sources for the luminosity difference. However, He mass fraction differences as small as delta Y ~ 0.02 cannot be ruled out and may be sufficient to reproduce the double HB.Comment: 72 pages, 14 figures, 8 tables; published in The Astronomical Journal; electronic versions of all tables are available in the published versio

Copy number variation in African Americans

<p>Abstract</p> <p>Background</p> <p>Copy number variants (CNVs) have been identified in several studies to be associated with complex diseases. It is important, therefore, to understand the distribution of CNVs within and among populations. This study is the first report of a CNV map in African Americans.</p> <p>Results</p> <p>Employing a SNP platform with greater than 500,000 SNPs, a first-generation CNV map of the African American genome was generated using DNA from 385 healthy African American individuals, and compared to a sample of 435 healthy White individuals. A total of 1362 CNVs were identified within African Americans, which included two CNV regions that were significantly different in frequency between African Americans and Whites (17q21 and 15q11). In addition, a duplication was identified in 74% of DNAs derived from cell lines that was not present in any of the whole blood derived DNAs.</p> <p>Conclusion</p> <p>The Affymetrix 500 K array provides reliable CNV mapping information. However, using cell lines as a source of DNA may introduce artifacts. The duplication identified in high frequency in Whites and low frequency in African Americans on chromosome 17q21 reflects haplotype specific frequency differences between ancestral groups. The generation of the CNV map will be a valuable tool for identifying disease associated CNVs in African Americans.</p

A Chemical Composition Survey of the Iron-Complex Globular Cluster NGC 6273 (M 19)

Recent observations have shown that a growing number of the most massive Galactic globular clusters contain multiple populations of stars with different [Fe/H] and neutron-capture element abundances. NGC 6273 has only recently been recognized as a member of this "iron-complex" cluster class, and we provide here a chemical and kinematic analysis of > 300 red giant branch (RGB) and asymptotic giant branch (AGB) member stars using high resolution spectra obtained with the Magellan-M2FS and VLT-FLAMES instruments. Multiple lines of evidence indicate that NGC 6273 possesses an intrinsic metallicity spread that ranges from about [Fe/H] = -2 to -1 dex, and may include at least three populations with different [Fe/H] values. The three populations identified here contain separate first (Na/Al-poor) and second (Na/Al-rich) generation stars, but a Mg-Al anti-correlation may only be present in stars with [Fe/H] > -1.65. The strong correlation between [La/Eu] and [Fe/H] suggests that the s-process must have dominated the heavy element enrichment at higher metallicities. A small group of stars with low [alpha/Fe] is identified and may have been accreted from a former surrounding field star population. The cluster's large abundance variations are coupled with a complex, extended, and multimodal blue horizontal branch (HB). The HB morphology and chemical abundances suggest that NGC 6273 may have an origin that is similar to omega Cen and M 54.Comment: Accepted for Publication in The Astrophysical Journal; 50 pages; 18 figures; 8 tables; higher resolution figures are available upon request or in the published journal articl

The Acute Effects of Ischemic Preconditioning on Short-Duration Cycling: A Randomized Crossover Study

International Journal of Exercise Science 16(6): 148-158, 2023. There is recent interest from coaches and athletes regarding IPC as an effective way to generate better competitive outcomes. Regarding cycling specifically, the impact of IPC remains unclear. This study aimed to assess the effectiveness of IPC treatment for improving athletic performance during short-duration cycling. After the exclusion and inclusion criteria, there were 11 volunteers for the 3-minute cycling TT and 13 volunteers for the 6-minute cycling TT. All volunteers were competitive athletes of aerobic sports. The IPC treatment consisted of three alternating cycles of 5 minutes of 100% occlusion followed by 5 minutes of reperfusion to each leg. The sham treatment consisted of three alternating cycles of 1 minute of 100% occlusion followed by 1 minute of reperfusion to each leg. The main finding was that IPC significantly improved (p\u3c0.05) power output during 3-minute (4.22%) and 6-minute (2.29%) cycling TT relative to a sham. Additionally, about one-third of our participants required a tourniquet pressure higher than 220 mmHg to achieve 100% occlusion. These findings indicate ischemic preconditioning, administered bilaterally as three rounds of 5 minutes of total occlusion and ensuing reperfusion 20 minutes before a cycling TT, significantly enhanced average power output

The Effect of a High Fat Meal on Cerebral Vascular Function

It is well known that a single high fat meal (HFM) causes a robust and transient elevation in serum triglycerides (TG). This elevation in serum TG is a primary contributor to the post-prandial attenuation of peripheral vascular endothelial function, as assessed by flow-mediated dilation in the brachial artery. Whether a similar impairment in vascular reactivity can be observed in the cerebral circulation remains unknown, and was the focus of this investigation. PURPOSE: To test the hypothesis that cerebral vascular function is impaired following a HFM. METHODS: End-tidal carbon dioxide partial pressure (PETCO2), middle cerebral artery blood velocity (MCAVmean), calculated cerebral vascular conductance index (CVCI; MCAVmean/mean arterial pressure) and cerebral vasodilator response to rebreathing induced hypercapnia (% increase in CVC from baseline at common maximal ΔPETCO2) were assessed in 6 healthy young men (27 ±5 years). Measures were assessed during fasted baseline and again at 2 and 4 h post meal consumption (HFM day) or at a similar time point in the fasted state (TC day). The two visits were separated by 2-7 days and were conducted in a randomized order. Blood lipids were assessed at baseline and at the 2 h time point into each respective condition. RESULTS: As expected, consumption of the HFM significantly elevated serum TG concentrations relative to TC at 2 h (HFM: 101±38 to 169±77mg/dl, TC: 107±32 to 92±31mg/dl, P=0.007). However, the HFM had no effect of cerebral vasodilator capacity during rebreathing induced hypercapnia. The maximal increase in %CVC achieved at the highest common ΔPETCO2 during all conditions within each subject was unchanged during 2hr and 4hr post HFM or TC (condition x time interaction: P=0.96). Similarly, the slope of the change in %CVC per change in ΔPETCO2 was unaffected by HFM across time (P=0.49). CONCLUSION: Contrary to our hypothesis, and unlike the peripheral vasculature, our preliminary data suggest that the cerebral circulation appears to be protected from the acute negative effects of a high fat meal