The establishment of a Management Information Systems research center at the Naval Postgraduate School.

This thesis investigates the opportunity for the establishment of a Management Information Systems research center at the Naval Postgraduate School and the unique purpose it would serve within the Department of Defense community. Following the analysis of five existing information systems research centers and their various objectives and activities, pertinent issues regarding the Naval Postgraduate School are identified through interviews of relevant faculty and staff. A mission is identified for a Naval Postgraduate School "Information Systems Research Center", and a strategy involving the center's objectives and activities is suggested.http://archive.org/details/establishmentofm00feilLieutenant Commander, United States NavyApproved for public release; distribution is unlimited

Digital in-line soft x-ray holography with element contrast

Digital in-line soft x-ray holography (DIXH) was used to image immobilized polystyrene and iron oxide particles and to distinguish them based on their different x-ray absorption cross sections in the vicinity of the carbon K-absorption edge. The element-specific information from the resonant DIXH images was correlated with high-resolution scanning electron microscopy (SEM) pictures. We also present DIXH images of a cell nucleus and compare the contrast obtained for nuclear components with the appearance in optical microscopy

Soft X ray holographic microscopy of chromosomes with high aspect ratio pinholes

We used digital in-line soft X-ray holography (DIXH) in the Gabor geometry to image human chromosomes. The divergent wave front was generated by diffraction of synchrotron radiation from a high aspect ratio pinhole. As under our experimental conditions the achievable resolution depends on the pinhole radius, high aspect ratio holes with diameters in the 100 nm range were prepared by focused ion beam (FIB) milling. The central maximum of the obtained Airy pattern was used to image chromosomes prepared from metaphase HeLa cells at experimental resolutions of 370±40 nm with soft X-rays at 260 eV photon energy provided by the BESSY II synchrotron radiation facility

Digital in-line X-ray holography with zone plates

Single pulse imaging with radiation provided by free-electron laser sources is a promising approach towards X-ray microscopy, which is expected to provide high resolution images of biological samples unaffected by radiation damage. One fully coherent imaging technique for this purpose is digital in-line holography. Key to its successful application is the creation of X-ray point sources with high photon flux. In this study we applied zone plates to create such point sources with synchrotron radiation provided by the storage ring BESSY II. The obtained, divergent light cone is applied to holographic microscopy of biological objects such as critical point dried Navicula perminuta diatoms and human cells using photons with an energy of 250 eV. Compared to conventional experiments employing pinholes, exposure times are reduced by two orders of magnitude

Coherent Imaging of Biological Samples with Femtosecond Pulses at the Free Electron Laser FLASH

Coherent x-ray imaging represents a new window to imaging noncrystalline, biological specimens at unprecedented resolutions. The advent offree-electron lasers (FEL) allows extremely high flux densities to be delivered to a specimen resulting in stronger scattered signal from these samples to be measured. In the best case scenario, the diffraction pattern is measured before the sample is destroyed by these intense pulses, as the processes involved in radiation damage may be substantially slower than the pulse duration. In this case, the scattered signal can be interpreted and reconstructed to yield a faithful image of the sample at a resolution beyond the conventional radiation damage limit. We employ coherent x-ray diffraction imaging (CXDI) using the free-electron LASer in Hamburg (FLASH) in a non-destructive regime to compare images ofa biological sample reconstructed using different, single, femtosecond pulses of FEL radiation. Furthermore, for the first time, we demonstrate CXDI, in-line holography and Fourier transform holography (FTH) of the same unicellular marine organism using an FEL and present diffraction data collected using the third harmonic of FLASH, reaching into the water window. We provide quantitative results for the resolution of the CXDI images as a function of pulse intensity, and compare this with the resolutions achieved with in-line holography and FTH

Validation of transpulmonary thermodilution variables in hemodynamically stable patients with heart diseases

BACKGROUND Transpulmonary thermodilution is recommended in the treatment of critically ill patients presenting with complex shock. However, so far it has not been validated in hemodynamically stable patients with heart disease. METHODS We assessed the validity of cardiac output, global end-diastolic volume index (GEDVI), an established marker of preload thought to reflect the volume of all four heart chambers, global ejection fraction (GEF) and cardiac function index (CFI) as variables of cardiac function, and extravascular lung water index (EVLWI) as indicator of pulmonary edema in 29 patients undergoing elective left and right heart catheterization including left ventricular angiography with stable coronary heart disease and normal cardiac function (controls, n = 11), moderate-to-severe aortic valve stenosis (AS, n = 10), or dilated cardiomyopathy (DCM, n = 8). RESULTS Cardiac output was similar in controls, AS, and DCM, with good correlation between transpulmonary thermodilution and pulmonary artery catheter using the Fick method (r = 0.69, p < 0.0001). Left ventricular end-diastolic volume was normal in controls and AS, but significantly higher in DCM (104 ± 37 vs 135 ± 63 vs 234 ± 24 ml, p < 0.01). GEDVI did not differentiate between patients with normal and patients with enlarged left ventricular end-diastolic volume (848 ± 128 vs 882 ± 213 ml m-2, p = 0.60). No difference in GEF and CFI was found between patients with normal and patients with reduced left ventricular ejection fraction. Patients with AS but not DCM had higher EVLWI than controls (9 ± 2 vs 12 ± 4 vs 11 ± 3 ml kg-1, p = 0.04), while there was only a trend in pulmonary artery occlusion pressure (8 ± 3 vs 10 ± 5 vs 14 ± 7 mmHg, p = 0.05). CONCLUSIONS Cardiac output measurement by transpulmonary thermodilution is unaffected by differences in ventricular size and outflow obstruction. However, GEDVI did not identify markedly enlarged left ventricular end-diastolic volumes, and neither GEF nor CFI reflected the increased heart chamber volumes and markedly impaired left ventricular function in patients with DCM. In contrast, EVLWI is probably a sensitive marker of subclinical pulmonary edema particularly in patients with elevated left-ventricular-filling pressure irrespective of differences in left ventricular function

Coherent Imaging of Biological Samples with Femtosecond Pulses at the Free Electron Laser FLASH

Coherent x-ray imaging represents a new window to imaging noncrystalline, biological specimens at unprecedented resolutions. The advent offree-electron lasers (FEL) allows extremely high flux densities to be delivered to a specimen resulting in stronger scattered signal from these samples to be measured. In the best case scenario, the diffraction pattern is measured before the sample is destroyed by these intense pulses, as the processes involved in radiation damage may be substantially slower than the pulse duration. In this case, the scattered signal can be interpreted and reconstructed to yield a faithful image of the sample at a resolution beyond the conventional radiation damage limit. We employ coherent x-ray diffraction imaging (CXDI) using the free-electron LASer in Hamburg (FLASH) in a non-destructive regime to compare images ofa biological sample reconstructed using different, single, femtosecond pulses of FEL radiation. Furthermore, for the first time, we demonstrate CXDI, in-line holography and Fourier transform holography (FTH) of the same unicellular marine organism using an FEL and present diffraction data collected using the third harmonic of FLASH, reaching into the water window. We provide quantitative results for the resolution of the CXDI images as a function of pulse intensity, and compare this with the resolutions achieved with in-line holography and FTH

Digital In-line Holography with femtosecond VUV radiation provided by the Free-electron laser FLASH

Femtosecond vacuum ultraviolet (VUV) radiation provided by the free-electron laser FLASH was used for digital in-line holographic microscopy and applied to image particles, diatoms and critical point dried fibroblast cells. To realize the classical in-line Gabor geometry, a 1 microm pinhole was used as spatial filter to generate a divergent light cone with excellent pointing stability. At a fundamental wavelength of 8 nm test objects such as particles and diatoms were imaged at a spatial resolution of 620 nm. In order to demonstrate the applicability to biologically relevant systems, critical point dried rat embryonic fibroblast cells were for the first time imaged with free-electron laser radiation