Identity Politics: The Weightiness of Black Womanhood in LIS

Presented at the 11th National Conference of African American Librarian

Introducing a Public Advocate into the Foreign Intelligence Surveillance Act's Courts: Select Legal Issues

This report explores government surveillance act and other difficult constitutional issues prompted by the idea of including a new adversary in established under the Foreign Intelligence Surveillance Act of 1978 (FISA) FISA court proceedings

Prostate Stereotactic Ablative Radiation Therapy Using Volumetric Modulated Arc Therapy to Dominant Intraprostatic Lesions

PurposeTo investigate boosting dominant intraprostatic lesions (DILs) in the context of stereotactic ablative radiation therapy (SABR) and to examine the impact on tumor control probability (TCP) and normal tissue complication probability (NTCP).Methods and MaterialsTen prostate datasets were selected. DILs were defined using T2-weighted, dynamic contrast-enhanced and diffusion-weighted magnetic resonance imaging. Four plans were produced for each dataset: (1) no boost to DILs; (2) boost to DILs, no seminal vesicles in prescription; (3) boost to DILs, proximal seminal vesicles (proxSV) prescribed intermediate dose; and (4) boost to DILs, proxSV prescribed higher dose. The prostate planning target volume (PTV) prescription was 42.7 Gy in 7 fractions. DILs were initially prescribed 115% of the PTVProstate prescription, and PTVDIL prescriptions were increased in 5% increments until organ-at-risk constraints were reached. TCP and NTCP calculations used the LQ-Poisson Marsden, and Lyman-Kutcher-Burman models respectively.ResultsWhen treating the prostate alone, the median PTVDIL prescription was 125% (range: 110%-140%) of the PTVProstate prescription. Median PTVDIL D50% was 55.1 Gy (range: 49.6-62.6 Gy). The same PTVDIL prescriptions and similar PTVDIL median doses were possible when including the proxSV within the prescription. TCP depended on prostate α/β ratio and was highest with an α/β ratio = 1.5 Gy, where the additional TCP benefit of DIL boosting was least. Rectal NTCP increased with DIL boosting and was considered unacceptably high in 5 cases, which, when replanned with an emphasis on reducing maximum dose to 0.5 cm3 of rectum (Dmax0.5cc), as well as meeting existing constraints, resulted in considerable rectal NTCP reductions.ConclusionsBoosting DILs in the context of SABR is technically feasible but should be approached with caution. If this therapy is adopted, strict rectal constraints are required including Dmax0.5cc. If the α/β ratio of prostate cancer is 1.5 Gy or less, then high TCP and low NTCP can be achieved by prescribing SABR to the whole prostate, without the need for DIL boosting

Rate versus rhythm control and outcomes in patients with atrial fibrillation and chronic kidney disease: Data from the GUSTO-III Trial

Background: Atrial fi brillation (AF) and chronic kidney disease (CKD) have both beenshown to portend worse outcomes after acute myocardial infarction (MI); however, the benefi tof a rhythm control strategy in patients with CKD post-MI is unclear.Methods: We prospectively studied 985 patients with new-onset AF post-MI in theGUSTO-III trial, of whom 413 (42%) had CKD (creatinine clearance < 60 mL/min).A rhythm control strategy, defi ned as the use of an antiarrhythmic medication and/orelectrical cardioversion, was used in 346 (35%) of patients.Results: A rhythm control strategy was used in 34% of patients with CKD and 36% of patientswith no CKD. At hospital discharge, sinus rhythm was present in 487 (76%) of patients treatedwith a rate control strategy, vs. 276 (80%) in those treated with rhythm control (p = 0.20). CKDwas associated with a lower odds of sinus rhythm at discharge (unadjusted OR 0.56, 95% CI0.38–0.84, p < 0.001). However, in multivariable analyses, treatment with a rhythm controlstrategy was not associated with discharge rhythm (HR 1.068, 95% CI 0.69–1.66, p = 0.77),30-day mortality (HR 0.78, 95% CI 0.54–1.12, p = 0.18) or mortality from day 30 to 1 year(HR 1.00, 95% CI 0.59–1.69, p = 0.99). CKD status did not signifi cantly impact the relationshipbetween rhythm control and outcomes.Conclusions: Treatment with a rhythm or rate control strategy does not signifi cantly impactshort-term or long-term mortality in patients with post-MI AF, regardless of kidney disease status.Future studies to investigate the optimal management of AF in CKD patients are needed

Late-Stage Diagenetic Concretions in the Murray Formation, Gale Crater, Mars

Concretions are prevalent features in the generally lacustrine deposits of the Murray formation in Gale crater. In this work, we document the morphologic, textural, and chemical properties of these concretions throughout 300 m of Murray formation stratigraphy from Mars Science Laboratory observations between Sols 750–1900. We interpret these observations to constrain the timing and composition of post-depositional fluid events at Gale crater. We determine that the overall diversity of concretion morphology, size, texture, and chemistry throughout the Murray formation indicates that concretions formed in multiple, likely late diagenetic, episodes with varying fluid chemistries. Four major concretion assemblages are observed at distinct stratigraphic intervals and approximately correlate with major distinct chemical enrichments in Mg-S-Ni-Cl, Mn-P, and Ca-S, among other local enrichments. Different concretion size populations and complex relationships between concretions and veins also suggest multiple precipitation events at Gale crater. Many concretions likely formed during late diagenesis after sediment compaction and lithification, based on observations of concretions preserving primary host rock laminations without differential compaction. An upsection decrease in overall concretion size corresponds to an inferred upsection decrease in porosity and permeability, thus constraining concretion formation as postdating fluid events that produced initial cementation and porosity loss. The combined observations of late diagenetic concretions and distinct chemical enrichments related to concretions allow constraints to be placed on the chemistry of late stage fluids at Gale crater. Collectively, concretion observations from this work and previous studies of other diagenetic features (veins, alteration halos) suggest at least six post-depositional events that occurred at Gale crater after the deposition of the Murray formation

Non-perturbative Euler-Heisenberg Lagrangian and Paraelectricity in Magnetized Massless QED

In this paper we calculate the non-perturbative Euler-Heisenberg Lagrangian for massless QED in a strong magnetic field $H$, where the breaking of the chiral symmetry is dynamically catalyzed by the external magnetic field via the formation of an electro-positron condensate. This chiral condensate leads to the generation of dynamical parameters that have to be found as solutions of non-perturbative Schwinger-Dyson equations. Since the electron-positron pairing mechanism leading to the breaking of the chiral symmetry is mainly dominated by the contributions from the infrared region of momenta much smaller than $\sqrt{eH}$, the magnetic field introduces a dynamical ultraviolet cutoff in the theory that also enters in the non-perturbative Euler-Heisenberg action. Using this action, we show that the system exhibits a significant paraelectricity in the direction parallel to the magnetic field. The nonperturbative nature of this effect is reflected in the non-analytic dependence of the obtained electric susceptibility on the fine-structure constant. The strong paraelectricity in the field direction is linked to the orientation of the electric dipole moments of the pairs that form the chiral condensate. The large electric susceptibility can be used to detect the realization of the magnetic catalysis of chiral symmetry breaking in physical systems.Comment: 18 pages, to be published in NP

Developing a class solution for Prostate Stereotactic Ablative Body Radiotherapy (SABR) using Volumetric Modulated Arc Therapy (VMAT)

Background and purpose To develop a class solution for prostate Stereotactic Ablative Radiotherapy (SABR) using Volumetric Modulated Arc Therapy (VMAT). Materials and methods Seven datasets were used to compare plans using one 360° arc (1FA), one 210° arc (1PA), two full arcs and two partial arcs. Subsequently using 1PA, fifteen datasets were compared using (i) 6 mm CTV–PTV margins, (ii) 8 mm CTV–PTV margins and (iii) including the proximal SV within the CTV. Monaco™ 3.2 (Elekta™) was used for planning with the Agility™ MLC system (Elekta™). Results Highly conformal plans were produced using all four arc arrangements. Compared to 1FA, 1PA resulted in significantly reduced rectal doses, and monitor units and estimated delivery times were reduced in six of seven cases. Using 6 mm CTV–PTV margins, planning constraints were met for all fifteen datasets. Using 8 mm margins required relaxation of the uppermost bladder constraint in three cases to achieve adequate coverage, and, compared to 6 mm margins, rectal and bladder doses significantly increased. Including the proximal SV required relaxation of the uppermost bladder and rectal constraints in two cases, and rectal and bladder doses significantly increased. Conclusions Prostate SABR VMAT is optimal using 1PA. 6 mm CTV–PTV margins, compatible with daily fiducial-based IGRT, are consistently feasible in terms of target objectives and OAR constraints

Skunk River Review Fall 2003, vol 15

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