Preliminary design study - Oxidizer tank helium pressure regulator, Flox-Atlas, airborne Final report

Oxidizer tank helium pressure regulator compatible with fluorine-liquid oxyge

The spin vector of Venus determined from Magellan data

A control network of the north polar region of Venus has been established by selecting and measuring control points on full-resolution radar strips. The measurements were incorporated into a least-squares adjustment program that improved initial estimates of the coordinates of the control points, pole direction, and rotation rate of Venus. The current dataset contains 4206 measurements of 606 points on 619 radar strips. The accuracy of the determination is driven by spacecraft ephemeris errors. An accurate estimate of the rotation period of Venus was obtained by applying an ephemeris improvement technique. The second cycle closure orbits improved ephemeris solutions for 40 orbits (376-384, 520-528, 588-592, 658-668, 1002-1010, 1408-1412, 1746-1764, and 2166-2170) are included and fixed in the geodetic control computations, thus trying the network to the J2000 coordinate system

Relationship Between Body Fat Distribution and Cardiovascular Disease Risk Biomarkers Among Firefighters

Firefighters are at risk of premature mortality due to cardiovascular disease (CVD). Firefighting is linked to elevations in oxidative stress, inflammation, and stress biomarkers, which all play a role in the development and progression of CVD. High prevalence rates of overweight and obesity have been found among U.S. firefighters. Obesity is considered a CVD risk factor, and firefighters who are classified as overweight or obese have been shown to express lower levels of high-density lipoprotein cholesterol (HDL-C) and higher levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), and biomarkers of oxidative stress and inflammation. However, little is known regarding the relationships between fat mass distribution and CVD biomarkers among firefighters. This information can aid the understanding of CVD risk factors among firefighters. PURPOSE: This study examined the relationship between body composition measures and traditional and non-traditional CVD biomarkers among firefighters. METHODS: Ninety-eight career, structural male firefighters (age = 35.1±9.6 yrs; weight = 94.3±15.4 kg; height = 178.4±13.2 cm) from a local fire department were studied. Body composition (i.e., body fat percentage, BF%) was assessed via dual x-ray absorptiometry. Fasted blood samples were analyzed for concentrations of lipids, advanced oxidation protein products (AOPP), and ultra-sensitive C-reactive protein (CRP). Ordinary least square regression analyses were used to assess the relationship between body composition and blood biomarkers. RESULTS: Gynoid fat percentage was inversely predictive (p\u3c0.05) of AOPP, TC, LDL-C, and TG, as well as positively related (p\u3c0.05) to HDL-C, while android fat percentage was positively predictive (p\u3c0.05) of AOPP, CRP, and TG, as well as inversely related (p\u3c0.05) to HDL-C. Increased BF% was positively predictive (p\u3c0.05) of CRP, TC, and LDL-C. CONCLUSION: These findings provide insight into the relationship between body composition and various biomarkers of CVD risk, and may aid future interventions aimed at attenuating CVD risk among firefighters

Grid-based methods for biochemical ab initio quantum chemical applications

A initio quantum chemical methods are seeing increased application in a large variety of real-world problems including biomedical applications ranging from drug design to the understanding of environmental mutagens. The vast majority of these quantum chemical methods are {open_quotes}spectral{close_quotes}, that is they describe the charge distribution around the nuclear framework in terms of a fixed analytic basis set. Despite the additional complexity they bring, methods involving grid representations of the electron or solvent charge can provide more efficient schemes for evaluating spectral operators, inexpensive methods for calculating electron correlation, and methods for treating the electrostatic energy of salvation in polar solvents. The advantage of mixed or {open_quotes}pseudospectral{close_quotes} methods is that they allow individual non-linear operators in the partial differential equations, such as coulomb operators, to be calculated in the most appropriate regime. Moreover, these molecular grids can be used to integrate empirical functionals of the electron density. These so-called density functional methods (DFT) are an extremely promising alternative to conventional post-Hartree Fock quantum chemical methods. The introduction of a grid at the molecular solvent-accessible surface allows a very sophisticated treatment of a polarizable continuum solvent model (PCM). Where most PCM approaches use a truncated expansion of the solute`s electric multipole expansion, e.g. net charge (Born model) or dipole moment (Onsager model), such a grid-based boundary-element method (BEM) yields a nearly exact treatment of the solute`s electric field. This report describes the use of both DFT and BEM methods in several biomedical chemical applications

An analog retina model for detecting dim moving objects against a bright moving background

We are interested in applications that require the ability to track a dim target against a bright, moving background. Since the target signal will be less than or comparable to the variations in the background signal intensity, sophisticated techniques must be employed to detect the target. We present an analog retina model that adapts to the motion of the background in order to enhance targets that have a velocity difference with respect to the background. Computer simulation results and our preliminary concept of an analog 'Z' focal plane implementation are also presented

Environmental effects on the structure of metal ion-DOTA complexes: An ab initio study of radiopharmaceutical metals.

Quantum mechanical calculations were performed to study the differences between the important radiopharmaceutical metals yttrium (Y) and indium (In) bound by DOTA and modified DOTA molecules. Energies were calculated at the MP2/6-31+G(d)//HF/6-31G(d) levels, using effective core potentials on the Y and In ions. Although the minimum energy structures obtained are similar for both metal ion-DOTA complexes, changes in coordination and local environment significantly affect the geometries and energies of these complexes. Coordination by a single water molecule causes a change in the coordination number and a change in the position of the metal ion in In-DOTA; but, Y-DOTA is hardly affected by water coordination. When one of the DOTA carboxylates is replaced by an amide, the coordination energy for the amide arm shows a large variation between the Y and In ions. Optimizations including water and guandinium moieties to approximate the effects of antibody binding indicate a large energy cost for the DOTA-chelated In to adopt the ideal conformation for antibody binding