Defining Petrophysical Units of the Palmer Deep Sites from Leg 178

Palmer Deep, on the inner continental shelf southwest of Anvers Island off the Antarctic Peninsula, is a glacially overdeepened basin consisting of three subbasins. Two sites, 1098 and 1099, were drilled in the Palmer Deep area. A high-resolution porosity curve has been calculated from density data and subsequently plotted against the shipboard lithologic logs. These new data correspond accurately to the lithologic logs, magnetic susceptibility, and gamma ray attenuation (GRA) density data and offer information on the heterogeneity of the sediments. Petrophysical groups have been generated to investigate interrelationships between different physical attributes. To develop these petrophysical groups, crossplots of the available physical properties data were performed. The results for the GRA density and magnetic susceptibility crossplots demonstrate distinct clusters. Plotting the magnetic susceptibility and GRA density data logs (divided into these new petrophysical groups) against lithology provided information to subdivide the lithologic unit(s) into a series of petrophysical units

A note on NMHV form factors from the Gra{\ss}mannian and the twistor string

In this note we investigate Gra{\ss}mannian formulas for form factors of the chiral part of the stress-tensor multiplet in $\mathcal{N}=4$ superconformal Yang-Mills theory. We present an all-$n$ contour for the $G(3,n+2)$ Gra{\ss}mannian integral of NMHV form factors derived from on-shell diagrams and the BCFW recursion relation. In addition, we study other $G(3,n+2)$ formulas obtained from the connected prescription introduced recently. We find a recursive expression for all $n$ and study its properties. For $n \geq 6$, our formula has the same recursive structure as its amplitude counterpart, making its soft behaviour manifest. Finally, we explore the connection between the two Gra{\ss}mannian formulations, using the global residue theorem, and find that it is much more intricate compared to scattering amplitudes.Comment: 21 pages, 3 figures; v2: JHEP version + minor correction

In Vivo Biotinylation of the Toxoplasma Parasitophorous Vacuole Reveals Novel Dense Granule Proteins Important for Parasite Growth and Pathogenesis.

UnlabelledToxoplasma gondii is an obligate intracellular parasite that invades host cells and replicates within a unique parasitophorous vacuole. To maintain this intracellular niche, the parasite secretes an array of dense granule proteins (GRAs) into the nascent parasitophorous vacuole. These GRAs are believed to play key roles in vacuolar remodeling, nutrient uptake, and immune evasion while the parasite is replicating within the host cell. Despite the central role of GRAs in the Toxoplasma life cycle, only a subset of these proteins have been identified, and many of their roles have not been fully elucidated. In this report, we utilize the promiscuous biotin ligase BirA* to biotinylate GRA proteins secreted into the vacuole and then identify those proteins by affinity purification and mass spectrometry. Using GRA-BirA* fusion proteins as bait, we have identified a large number of known and candidate GRAs and verified localization of 13 novel GRA proteins by endogenous gene tagging. We proceeded to functionally characterize three related GRAs from this group (GRA38, GRA39, and GRA40) by gene knockout. While Δgra38 and Δgra40 parasites showed no altered phenotype, disruption of GRA39 results in slow-growing parasites that contain striking lipid deposits in the parasitophorous vacuole, suggesting a role in lipid regulation that is important for parasite growth. In addition, parasites lacking GRA39 showed dramatically reduced virulence and a lower tissue cyst burden in vivo Together, the findings from this work reveal a partial vacuolar proteome of T. gondii and identify a novel GRA that plays a key role in parasite replication and pathogenesis.ImportanceMost intracellular pathogens reside inside a membrane-bound vacuole within their host cell that is extensively modified by the pathogen to optimize intracellular growth and avoid host defenses. In Toxoplasma, this vacuole is modified by a host of secretory GRA proteins, many of which remain unidentified. Here we demonstrate that in vivo biotinylation of proximal and interacting proteins using the promiscuous biotin ligase BirA* is a powerful approach to rapidly identify vacuolar GRA proteins. We further demonstrate that one factor identified by this approach, GRA39, plays an important role in the ability of the parasite to replicate within its host cell and cause disease

Acceleration and Classical Electromagnetic Radiation

Classical radiation from an accelerated charge is reviewed along with the reciprocal topic of accelerated observers detecting radiation from a static charge. This review commemerates Bahram Mashhoon's 60th birthday.Comment: To appear in Gen. Rel. Gra

On the Uniqueness of the Papapetrou--Majumdar Metric

We establish the equality of the ADM mass and the total electric charge for asymptotically flat, static electrovac black hole spacetimes with completely degenerate, not necessarily connected horizon.Comment: 9 pages, latex, no figures, to appear in Class. Quantum Gra

Dynamic panel data: A useful technique in experiments

Numerous experimental studies use a panel approach to analyze repeated experiments involving a large number of periods. They use “static” panel techniques and do not incorporate any temporal dependency (lags) of the dependent variable. This paper introduces dynamic panel data techniques to experimental economists. This is a standard tool in many other fields of economics and might also be useful in our discipline. It uses the lags of the dependent variable as explanatory variables. Although the coefficients on lagged dependent variables might be far from our interest, the introduction of these lags becomes crucial to control for the dynamics of the process. To show the advantages of this technique, we have compared two datasets using static and dynamic panel data. We conclude that the use of dynamic panel data models in the context of experiments allows to unravel new relationships between experimental variables and highlighting new paths in behaviors

Covariance of noncommutative Grassmann star product

Using the Coherent states of many fermionic degrees of freedom labeled by Gra\ss mann variables, we introduce the noncommutative (precisely non anticommutative) Gra\ss mann star product. The covariance of star product under unitary transformations, particularly canonical ones, is studied. The super star product, based on supercoherent states of supersymmetric harmonic oscillator, is also considered