On the volatility of volatility

The Chicago Board Options Exchange (CBOE) Volatility Index, VIX, is calculated based on prices of out-of-the-money put and call options on the S&P 500 index (SPX). Sometimes called the "investor fear gauge," the VIX is a measure of the implied volatility of the SPX, and is observed to be correlated with the 30-day realized volatility of the SPX. Changes in the VIX are observed to be negatively correlated with changes in the SPX. However, no significant correlation between changes in the VIX and changes in the 30-day realized volatility of the SPX are observed. We investigate whether this indicates a mispricing of options following large VIX moves, and examine the relation to excess returns from variance swaps.Comment: 15 pages, 12 figures, LaTe

Overwinter Changes in Dry Aggregate Size Distribution Influencing Wind Erodibility in a Spring Wheat-Summerfallow Cropping System

A long-term study of the wind erodibility properties of a two-year spring wheat-summerfallow cropping systems was started in 1988 in south-central North Dakota as part of an USDA-ARS led effort to construct a process-oriented soil erosion predictive model. Observations were conducted on a conservation tillage experiment established in 1984 on soil classified in the U.S. as Typic-Pachic Haploborolls and in Canada as Brown to Dark Brown Chenozemic. The experiment included four residue-management treatments defined by targeted residue coverages: no-till, \u3e 60% cover; minimal-till, 30% to 60% cover and undercutter dominated; conventional-till, \u3c 30% cover and disk dominated; low-residue, \u3c 5 % cover. Fall and spring measurements of dry aggregate size distribution (ASD) of surface soil (0 to 4 cm depth), and overwinter changes in ASD are reported here. A rotary sieve produced six size fractions ranging from \u3c 0.42 mm to \u3e 19.2 mm diameter. Measurements of ASD are expressed as geometric mean diameter (GMD) or erodible fraction (EF: fraction \u3c 0.84 mm). Two major influences on overwinter changes in ASD were observed: (i) During the drier part of a multiyear weather cycle (1988 to 1990), disaggregative changes were observed, with a lowering of GMDs and an increase in EFs. Wetter years (1991 to 1993) brought mixed to aggregative ASD changes. (ii) The phase of the 21-month fallow period strongly affected overwinter ASD change, with large, aggregative changes (GMD up, EF down) observed over the first winter of the fallow period (stubble phase) and mixed aggregative to disaggregative changes observed in the second winter of fallow (residue phase). Tillage treatments had little apparent effect on overwinter ASD changes. Single and multiple regressions indicate that various factors would associate with significant fractions of variance in overwinter GMD change: (i) weather factors - (a) number of days with snowcover, (b) number of freeze-thaw cycles, and (c) precipitation in the fall; (ii) crop growth in years before the year of fallow; (iii) phase of the fallow period; and (iv) GMD level in the fall

Crevice Interments Deconstructed

The discovery of two well preserved human crania in a crevice overlooking a spring fed creek near Austin, Texas, led to medico legal, archeological, and bioanthropological investigations aimed at understanding the context and biological affinity of the crania. Archeological excavations uncovered no evidence that the crania were interred in the crevice during prehistoric times. Skeletal analysis showed they were of Native American ancestry. Radiocarbon dating indicated they are contemporary to one another and probably date to the seventh or eighth century A.D. Measured stable isotopic rations of carbon ( 13 C/ 12 C) and nitrogen ( 15 N/ 14 N) derived from human bone collagen samples from the crania are not consistent with other burial populations from the region, having higher nitrogen values than all other comparative samples. The crania also showed polish from repeated handling and several of the molars in one cranium had been glued in place. Taken together, these lines of evidence suggest the crania were removed from an unknown locality outside the Central Texas region, kept in a private collection, and placed in the crevice recently

Glutathione Supplementation Attenuates Lipopolysaccharide-Induced Mitochondrial Dysfunction and Apoptosis in a Mouse Model of Acute Lung Injury

Acute lung injury (ALI) is a life threatening condition associated with hypoxemia, diffuse alveolar damage, inflammation, and loss of lung function. Lipopolysaccharide (LPS; endotoxin) from the outer membrane of Gram-negative bacteria is a major virulence factor involved in the development of ALI. The depletion of glutathione (GSH), an essential intra- and extra-cellular protective antioxidant, by LPS is an important event that contributes to the elevation in reactive oxygen species. Whether restoring GSH homeostasis can effectively ameliorate mitochondrial dysfunction and cellular apoptosis in ALI is unknown and therefore, was the focus of this study. In peripheral lung tissue of LPS-treated mice, hydrogen peroxide and protein nitration levels were significantly increased. Pre-treatment with GSH-ethyl ester (GSH-EE) prevented this increase in oxidative stress. LPS also increased the lactate/pyruvate ratio, attenuated SOD2 protein levels, and decreased ATP levels in the mouse lung indicative of mitochondrial dysfunction. Again, GSH-EE treatment preserved the mitochondrial function. Finally, our studies showed that LPS induced an increase in the mitochondrial translocation of Bax, caspase 3 activation, and nuclear DNA fragmentation and these parameters were all prevented with GSH-EE. Thus, this study suggests that GSH-EE supplementation may reduce the mitochondrial dysfunction associated with ALI

Excavations at 41LK67 a Prehistoric Site in the Choke Canyon Reservior, South Texas

In 1977-1978 excavations were conducted at 41 LK 67 in Live Oak County, south Texas, by the Center for Archaeological Research, The University of Texas at San Antonio. The investigation of this prehistoric archaeological site was part of an extensive program of reconnaissance and excavation necessitated by the construction of the Choke Canyon Reservoir on the Frio River by the Bureau of Reclamation. The site is situated in shallow colluvial deposits capping an old terrace remnant of the Frio River. The excavations involved 193 m2 in three separate areas and revealed Late Prehistoric and Late Archaic components. Recognizably older artifacts (including patinated chert flakes) from the surface and from excavations may represent older disturbed components or artifacts collected prehistorically from nearby sites. Radiocarbon dates, with medians ranging from 1590 to 660 B.C. (MASCA correction) are available only from the Late Archaic component. The principal kinds of debris recovered from the excavations are fire-cracked rock, cores and chipping debris, shells of snails and freshwater mussels, plainware potsherds, and chipped stone tools. Mussel shell was surprisingly abundant; more than 9000 specimens, including 3000 specimens identified taxonomically, were recovered. Fish otoliths were the only animal bones preserved, except for a few recent, intrusive elements. Debris frequencies from the two larger excavation blocks (Areas A and B) were factor analyzed. In most cases the analysis showed the strongest covariation occurring among different classes of chipping debris. For Area C factor analysis indicated that the strongest spatial patterning occurred in the upper part of the deposits. Unfortunately, the analysis was not particularly successful in defining activity sets. The small collection of chipped stone tools was examined microscopically. Two tool classes in particular, distally beveled tools (gouges) and quadrilateral bifaces (beveled knives) seem to represent more functionally specific tool forms, but other hafted bifaces (projectile points) show a wide range of use wear mostly unrelated to projectile use

Complex I dysfunction underlies the glycolytic switch in pulmonary hypertensive smooth muscle cells.

ATP is essential for cellular function and is usually produced through oxidative phosphorylation. However, mitochondrial dysfunction is now being recognized as an important contributing factor in the development cardiovascular diseases, such as pulmonary hypertension (PH). In PH there is a metabolic change from oxidative phosphorylation to mainly glycolysis for energy production. However, the mechanisms underlying this glycolytic switch are only poorly understood. In particular the role of the respiratory Complexes in the mitochondrial dysfunction associated with PH is unresolved and was the focus of our investigations. We report that smooth muscle cells isolated from the pulmonary vessels of rats with PH (PH-PASMC), induced by a single injection of monocrotaline, have attenuated mitochondrial function and enhanced glycolysis. Further, utilizing a novel live cell assay, we were able to demonstrate that the mitochondrial dysfunction in PH-PASMC correlates with deficiencies in the activities of Complexes I-III. Further, we observed that there was an increase in mitochondrial reactive oxygen species generation and mitochondrial membrane potential in the PASMC isolated from rats with PH. We further found that the defect in Complex I activity was due to a loss of Complex I assembly, although the assembly of Complexes II and III were both maintained. Thus, we conclude that loss of Complex I assembly may be involved in the switch of energy metabolism in smooth muscle cells to glycolysis and that maintaining Complex I activity may be a potential therapeutic target for the treatment of PH

Archeological 3D Mapping: The Structure from Motion Revolution

Mapping is a critical aspect of systematic documentation no matter where archaeologists work. From hand-drawn maps of excavation units to maps created with Total Data Stations or LiDAR scanning, today’s archaeologists have a suite of mapping techniques and technologies to choose from when documenting a site. Typically, spectacular sites often receive high resolution mapping, whereas everyday sites rarely do. Recently, however, a revolutionary technology and technique has been created that can produce highly accurate and precise three-dimensional maps and orthophotos of archaeological sites, features, and profiles at a fraction of the cost and time of LiDAR and intensive TDS mapping: Structure from Motion (SfM). SfM is a new digital photography processing technique for capturing highly detailed, three-dimensional (3D) data from almost any surface using digital cameras. This article introduces the various platforms SfM photographs can be collected from (UAV, kites, balloons, poles, and groundbased) and provides examples of different types of data SfM can provide. The Structure from Motion Revolution is unfolding across the globe at a rapid pace, and we encourage archaeologists to take advantage of this new recording method

Metabolic Changes Precede the Development of Pulmonary Hypertension in the Monocrotaline Exposed Rat Lung.

There is increasing interest in the potential for metabolic profiling to evaluate the progression of pulmonary hypertension (PH). However, a detailed analysis of the metabolic changes in lungs at the early stage of PH, characterized by increased pulmonary artery pressure but prior to the development of right ventricle hypertrophy and failure, is lacking in a preclinical animal model of PH. Thus, we undertook a study using rats 14 days after exposure to monocrotaline (MCT), to determine whether we could identify early stage metabolic changes prior to the manifestation of developed PH. We observed changes in multiple pathways associated with the development of PH, including activated glycolysis, increased markers of proliferation, disruptions in carnitine homeostasis, increased inflammatory and fibrosis biomarkers, and a reduction in glutathione biosynthesis. Further, our global metabolic profile data compare favorably with prior work carried out in humans with PH. We conclude that despite the MCT-model not recapitulating all the structural changes associated with humans with advanced PH, including endothelial cell proliferation and the formation of plexiform lesions, it is very similar at a metabolic level. Thus, we suggest that despite its limitations it can still serve as a useful preclinical model for the study of PH