Ram Pressure Stripping of Spiral Galaxies in Clusters

We use 3-dimensional SPH/N-BODY simulations to study ram pressure stripping of gas from spiral galaxies orbiting in clusters. We find that the analytic expectation of Gunn & Gott (1972) relating the gravitational restoring force provided by the disk to the ram pressure force, provides a good approximation to the radius that gas will be stripped from a galaxy. However, at small radii it is also important to consider the potential provided by the bulge component. A spiral galaxy passing through the core of a rich cluster such as Coma, will have its gaseous disk truncated to $\sim 4$ kpc, thus losing $\sim 80$ of its diffuse gas mass. The timescale for this to occur is a fraction of a crossing time $\sim 10^7$ years. Galaxies orbiting within poorer clusters, or inclined to the direction of motion through the intra-cluster medium will lose significantly less gas. We conclude that ram-pressure alone is insufficient to account for the rapid and widespread truncation of star-formation observed in cluster galaxies, or the morphological transformation of Sab's to S0's that is necessary to explain the Butcher-Oemler effect.Comment: 8 pages, 7 figures, to be published in MNRAS. Levels added/corrected on figures 3, 4 and

Defining Benchmark Status: An Application using Euro-Area Bonds

The introduction of the euro on 1 January 1999 created the conditions for an integrated government bond market in the euro area. Using a unique data set from the electronic trading platform Euro-MTS, we consider what is the benchmark' in this market. We develop and apply two definitions of benchmark status that differ from the conventional view that the benchmark is the security with lowest yield at a given maturity. Using Granger-causality and cointegration methods, we find a complex pattern of benchmark status in euro-area government bonds.

Bifurcation of Civil Trials

Despite its widespread and long-standing recognition as a valuable docket-control device, the bifurcation of issues in civil trials has generated considerable debate among legal scholars and judges. The state and federal courts both utilize bifurcation, andthe Supreme Court of Appeals in Virginia recognized the advantages of the procedural device as early as 1915. Nonetheless, authority for the bifurcation of issues in civil trials in Virginia has remained clouded. The Supreme Court of Virginia lifted at least some of the clouds when it decided Allstate Insurance Co. v. Wade, thereby rejecting the position taken in an amicus curiae brief filed by the Virginia Trial Lawyers Association that bifurcation is not authorized under Virginia law. The court further clarified the law of bifurcation when it issued its January 16, 2009 opinion in Centra Health, Inc. v. Mullins. Nevertheless, some doubts remain about the availability of the procedure in Virginia

Flexibility in the receptor-binding domain of the enzymatic colicin E9 is required for toxicity against Escherichia coli cells

The events that occur after the binding of the enzymatic E colicins to Escherichia coli BtuB receptors that lead to translocation of the cytotoxic domain into the periplasmic space and, ultimately, cell killing are poorly understood. It has been suggested that unfolding of the coiled-coil Mull receptor binding domain of the E colicins may be an essential step that leads to the loss of immunity protein from the colicin and immunity protein complex and then triggers the events of translocation. We introduced pairs of cysteine mutations into the receptor binding domain of colicin E9 (ColE9) that resulted in the formation of a disulfide bond located near the middle or the top of the R domain. After dithiothreitol reduction, the ColE9 protein with the mutations L359C and F412C (ColE9 L359C-F412C) and the ColE9 protein with the mutations Y324C and L447C (ColE9 Y324C-L447C) were slightly less active than equivalent concentrations of ColE9. On oxidation with diamide, no significant biological activity was seen with the ColE9 L359C-F412C and the ColE9 Y324C-L447C mutant proteins; however diamide had no effect on the activity of ColE9. The presence of a disulfide bond was confirmed in both of the oxidized, mutant proteins by matrix-assisted laser desorption ionization-time of flight mass spectrometry. The loss of biological activity of the disulfide-containing mutant proteins was not due to an indirect effect on the properties of the translocation or DNase domains of the mutant colicins. The data are consistent with a requirement for the flexibility of the coiled-coil R domain after binding to BtuB

Rhabdomyolysis in an HIV cohort: epidemiology, causes and outcomes.

BackgroundThe Literature on rhabdomyolysis in the HIV-positive population is sparse and limited. We aimed to explore the incidence, patient characteristics, etiologies and outcomes of rhabdomyolysis in a cohort of HIV-positive patients identified through the Johns Hopkins HIV clinical registry between June 1992 and April 2014.MethodsA retrospective analysis of 362 HIV-positive patients with non-cardiac CK elevation ≥1000 IU/L was performed. Both inpatients and outpatients were included. Incidence rate and potential etiologies for rhabdomyolysis were ascertained. The development of acute kidney injury (AKI, defined as doubling of serum creatinine), need for dialysis, and death in the setting of rhabdomyolysis were determined. Logistic regression was used to evaluate the association of peak CK level with the development of AKI.ResultsThree hundred sixty two cases of rhabdomyolysis were identified in a cohort of 7079 patients with a 38,382 person years follow-up time. The incidence rate was nine cases per 1000 person-years (95% CI: 8.5-10.5). Infection was the most common etiology followed by compression injury and drug/alcohol use. One-third of cases had multiple potential etiologies. AKI developed in 46% of cases; 20% of which required dialysis. Thirteen percent died during follow-up. After adjustment, AKI was associated with higher CK (OR 2.05 for each 1-log increase in CK [95% CI: 1.40-2.99]), infection (OR 5.48 [95% CI 2.65-11.31]) and higher HIV viral load (OR 1.22 per 1-log increase [95% CI: 1.03-1.45]).ConclusionRhabdomyolysis in the HIV-positive population has many possible causes and is frequently multifactorial. HIV-positive individuals with rhabdomyolysis have a high risk of AKI and mortality

Training That Works: Lessons from California\u27s Employment Training Panel Program

The authors provide an in-depth analysis of an incumbent worker training program funded through California\u27s unemployment insurance taxes.https://research.upjohn.org/up_press/1052/thumbnail.jp