We report on a highly selective experimental setup for particle-$\gamma$
coincidence experiments at the Super-Enge Split-Pole Spectrograph (SE-SPS) of
the John D. Fox Superconducting Linear ...Accelerator Laboratory at Florida State
University (FSU) using fast CeBr$_3$ scintillators for $\gamma$-ray detection.
Specifically, we report on the results of characterization tests for the first
five CeBr$_3$ scintillation detectors of the CeBr$_3$ Array (CeBrA) with
respect to energy resolution and timing characteristics. We also present
results from the first particle-$\gamma$ coincidence experiments successfully
performed with the CeBrA demonstrator and the FSU SE-SPS. We show that with the
new setup, $\gamma$-decay branching ratios and particle-$\gamma$ angular
correlations can be measured very selectively using narrow excitation energy
gates, which are possible thanks to the excellent particle energy resolution of
the SE-SPS. In addition, we highlight that nuclear level lifetimes in the
nanoseconds regime can be determined by measuring the time difference between
particle detection with the SE-SPS focal-plane scintillator and $\gamma$-ray
detection with the fast CeBrA detectors. Selective excitation energy gates with
the SE-SPS exclude any feeding contributions to these lifetimes.
The minimum pulse height selection method developed more than forty years ago to process the information provided by detectors with an energy spectrum responding to a Landau distribution is extended ...in this work to consider other information processing criteria such as the maximum pulse height and the pulse height closest to the mode. The latter is a selection method whereby the mode is calculated for a distribution and then, a pulse closest to it is selected from a given set and stored. We analyze the combined resolution of a set of identical sampling detectors in terms of the number of detectors and the shape of the characteristic pulse height distribution from a single detector.
To make this treatment as general as possible, five analytical forms are tested as symmetric and asymmetric pulse height distributions, applying to each of them the three selection methods mentioned above. We also compare these results with the average of the pulse heights in each case. For these evaluations, analytical calculations and Monte Carlo simulations were carried out. It was thus possible to select the most appropriate selection method based on the shape parameters of a distribution.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Fumonisins are mycotoxins produced by Fusarium verticillioides and F. proliferatum, fungi that are ubiquitous in corn (maize). Insect damage and some other environmental conditions result in the ...accumulation of fumonisins in corn-based products worldwide. Current methods of fumonisin detection rely on the use of immunoaffinity columns and high-performance liquid chromatography (HPLC). The use of aptamers offers a good alternative to the use of antibodies in fumonisin cleanup and detection due to lower costs and improved stability. Aptamers are single-stranded oligonucleotides that are selected using Systematic Evolution of Ligands by EXponential enrichment (SELEX) for their ability to bind to targets with high affinity and specificity. Sequences obtained after 18 rounds of SELEX were screened for their ability to bind to fumonisin B(1). Six unique sequences were obtained, each showing improved binding to fumonisin B(1) compared to controls. Sequence FB(1) 39 binds to fumonisin with a dissociation constant of 100 ± 30 nM and shows potential for use in fumonisin biosensors and solid phase extraction columns.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
To determine whether addition of basic fibroblast growth factor (bFGF), an angiogenic growth factor, enhances the angiogenic effects of transmyocardial laser revascularization (TMR).
TMR is an ...investigational therapy for treating patients with medically refractory angina not amenable to traditional therapies. Histologic and blood flow studies in animals have suggested that TMR enhances angiogenesis above that normally seen in ischemic myocardium. We tested the hypothesis that bFGF administered into TMR channels further enhance the angiogenic effects of TMR.
Chronic ischemia was created in 3 groups of dogs using an ameroid constrictor on the proximal LAD. In the bFGF group (n = 5) non-transmyocardial channels were created in the LAD territory and bFGF, (100 ng/ml) dissolved in pluronic gel was injected into the each channel. In the TMR group (n = 7), transmyocardial channels were created without bFGF. A control group (n = 7) had ischemia without TMR of bFGF. 5-bromo-2'-deoxyuridine (BrdU) was administered to mark proliferating cells. After 8 weeks survival, colored microspheres were injected to assess the regional myocardial blood flow.
TMR and TMR+bFGF increased total vascular density by approximately 40% over that observed in the control group. However, the number of large vessels (internal diameter > or = 50 microm) was doubled by the addition of bFGF, and this correlated with a 50% increase in the density of proliferating vascular cells and a tripling of the total estimated vascular cross sectional area. Blood flow to the LAD territory was increased by TMR compared to controls, with no further benefit observed in the bFGF group.
On a histologic basis, basic fibroblast growth factor further enhances angiogenesis following TMR in ischemic myocardium mainly by increasing the size but not the total number of vessels.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We report on a study of the Multiview Observatory for Solar Terrestrial Science (MOST) mission that will provide comprehensive imagery and time series data needed to understand the magnetic ...connection between the solar interior and the solar atmosphere/inner heliosphere. MOST will build upon the successes of SOHO and STEREO missions with new views of the Sun and enhanced instrument capabilities. This article is based on a study conducted at NASA Goddard Space Flight Center that determined the required instrument refinement, spacecraft accommodation, launch configuration, and flight dynamics for mission success. MOST is envisioned as the next generation great observatory positioned to obtain three-dimensional information of large-scale heliospheric structures such as coronal mass ejections, stream interaction regions, and the solar wind itself. The MOST mission consists of 2 pairs of spacecraft located in the vicinity of Sun-Earth Lagrange points L4 (MOST1, MOST3) and L5 (MOST2 and MOST4). The spacecraft stationed at L4 (MOST1) and L5 (MOST2) will each carry seven remote-sensing and three in-situ instrument suites, including a novel radio package known as the Faraday Effect Tracker of Coronal and Heliospheric structures (FETCH). MOST3 and MOST4 will carry only the FETCH instruments and are positioned at variable locations along the Earth orbit up to 20{\deg} ahead of L4 and 20{\deg} behind L5, respectively. FETCH will have polarized radio transmitters and receivers on all four spacecraft to measure the magnetic content of solar wind structures propagating from the Sun to Earth using the Faraday rotation technique. The MOST mission will be able to sample the magnetized plasma throughout the Sun-Earth connected space during the mission lifetime over a solar cycle.
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