Spectral sensor error analysis for measuring x-ray radiation drive using the DANTE diagnostic toward inertial confinement fusion experiments.

DANTE is a diagnostic used to measure the x-radiation drive produced by heating a high-Z cavity ("hohlraum") with high-powered laser beams. It records the spectrally and temporally resolved radiation flux at x-ray energies between 50 eV and 20 keV. Each sensor configuration on DANTE is composed of filters, mirrors, and x-ray diodes to define 18 different x-ray channels whose output is voltage as a function of time. The absolute flux is then determined from the photometric calibration of the sensor configuration and a spectral reconstructing algorithm. The reconstruction of the spectra vs time from the measured voltages and known response of each channel has presented challenges. We demonstrate a novel approach here for quantifying the error on the determined flux based on the channel sensor configuration and most commonly used reconstruction algorithm. In general, we find that the integrated spectral flux from a hohlraum can robustly be reconstructed (within ∼14%) using a traditional unfold approach with as few as ten channels due to the underlying assumption of a largely Planckian spectral intensity distribution.

DANTE as a primary temperature diagnostic for the NIF iron opacity campaign.

The Opacity Platform on the National Ignition Facility (NIF) has been developed to measure iron opacities at varying densities and temperatures relevant to the solar interior and to verify recent experimental results obtained at the Sandia Z-machine, that diverge from theory. The first set of NIF experiments collected iron opacity data at ∼150 eV to 160 eV and an electron density of ∼7 × 1021 cm-3, with a goal to study temperatures up to ∼210 eV, with electron densities of up to ∼3 × 1022 cm-3. Among several techniques used to infer the temperature of the heated Fe sample, the absolutely calibrated DANTE-2 filtered diode array routinely provides measurements of the hohlraum conditions near the sample. However, the DANTE-2 temperatures are consistently low compared to pre-shot LASNEX simulations for a range of laser drive energies. We have re-evaluated the estimated uncertainty in the reported DANTE-2 temperatures and also the error generated by varying channel participation in the data analysis. An uncertainty of ±5% or better can be achieved with appropriate spectral coverage, channel participation, and metrology of the viewing slot.

A genetic algorithm approach for reconstructing spectral content from filtered x-ray diode array spectrometers.

Filtered diode array spectrometers are routinely employed to infer the temporal evolution of spectral power from x-ray sources, but uniquely extracting spectral content from a finite set of broad, spectrally overlapping channel spectral sensitivities is decidedly nontrivial in these under-determined systems. We present the use of genetic algorithms to reconstruct a probabilistic spectral intensity distribution and compare to the traditional approach most commonly found in the literature. Unlike many of the previously published models, spectral reconstructions from this approach are neither limited by basis functional forms nor do they require a priori spectral knowledge. While the original intent of such measurements was to diagnose the temporal evolution of spectral power from quasi-blackbody radiation sources-where the exact details of spectral content were not thought to be crucial-we demonstrate that this new technique can greatly enhance the utility of the diagnostic by providing more physical spectra and improved robustness to hardware configuration for even strongly non-Planckian distributions.

Multiple roles of the DSCR1 (Adapt78 or RCAN1) gene and its protein product calcipressin 1 (or RCAN1) in disease.

The DSCR1 (Adapt78) gene is transiently induced by stresses to temporarily protect cells against further potentially lethal challenges. However, chronic expression of the DSCR1 (Adapt78) gene has now been implicated in several pathological conditions including Alzheimer's disease, Down syndrome and cardiac hypertrophy. Calcipressin 1 has been shown to function through direct binding and inhibition of the serine threonine protein phosphatase Calcineurin. Pharmacological inhibition of calcineurin, by the immunosuppressive drugs cyclosporin A and FK506, affects a wide variety of diseases. It is, therefore, likely that this endogenous calcineurin inhibitor, calcipressin 1, may also play a role in a variety of human diseases.

Semiempirical and ab initio conformational analysis of 2-methylene-8,8-dimethyl-1,4,6,10-tetraoxaspiro[4.5] decane with application of GIAO-SCF methods to NMR spectrum interpretation.

The GIAO-SCF method for calculating isotropic nuclear magnetic shielding values has been utilized to explain certain features in the 1H-NMR spectrum of 2-methylene-8,8-dimethyl-1,4,6,10-tetraoxaspiro[4.5] decane. Population distributions of the low-energy conformers based on their ab initio energies were used to produce weighting factors for the individual calculated shielding values to calculate the weighted average of the shielding values for a complete set of conformers. The differences in 1H chemical shifts between the hydrogens of the two methyl groups and between the axial and equatorial hydrogens in 2-methylene-8,8-dimethyl-1,4,6,10-tetraoxaspiro[4.5] decane were shown to be due to energy differences between the chair and boat orientations of the six-membered ring and contribution from a twist-boat conformation. Results suggest a hypothesis that intramolecular differences in chemical shift might be calculated to a greater degree of accuracy than chemical shifts calculated relative to a standard.

The effect of snoring and obstructive sleep apnea on the sleep quality of bed partners.

OBJECTIVE: To measure the effect of snoring and obstructive sleep apnea (OSA) on the sleep of snorers' bed partners and to determine whether a bed partner's sleep improves when snoring and OSA are treated. MATERIALS AND METHODS: We studied 10 married couples in which 1 member was undergoing polysomnography to evaluate suspected OSA. The patients and their spouses underwent simultaneous polysomnography. Midway through the 1-night study, the patients received nasal continuous positive airway pressure (CPAP) with the pressure adjusted to eliminate snoring and obstructive breathing events. Apnea-hypopnea index (episodes/hours of sleep time), arousal index (arousals/hours of sleep time), and sleep efficiency (percent time asleep) were calculated to measure sleep quality. RESULTS: The patients (all male) demonstrated a median (range) apnea-hypopnea index of 26 (3-75) that decreased to 7 (0-34) during the trial of nasal CPAP therapy (P < .05). During the CPAP trial, the median (range) arousal index of the spouses decreased from 21 (14-34) to 12 (4-27) (P < .01), and the spouses' median (range) sleep efficiency increased from 74% (56%-80%) to 87% (64%-95%) (P < .01). CONCLUSION: The elimination of snoring and OSA in these patients was associated with an improvement in the quality of their bed partners' sleep, as indicated by improved sleep efficiency and continuity, even when the spouses had been habitually exposed to snoring and OSA. Assuming that 480 minutes were spent in bed for sleep, a 13% improvement in sleep efficiency (i.e., from 74% to 87%) translates to an additional 62 minutes of sleep per night for the spouses of snorers with OSA.

Patient satisfaction with collaborative practice.

OBJECTIVE: To gather information on women's perceptions of the services delivered in collaborative obstetrics and gynecology practices and to determine whether patients perceive a difference in the delivery of services in a variety of practice settings. METHODS: A cross-sectional patient satisfaction survey was developed by the Collaborative Practice Advisory Group of ACOG. Ten collaborative practices were selected to participate: five in private offices, two in clinics, two in health maintenance organizations, and one in the military. Between April 15 and May 15, 1994, 3257 completed surveys were obtained for analysis. RESULTS: Between 71% and 92% of women, depending upon the practice setting, agreed with statements regarding the possible benefits from being cared for in a collaborative practice. The majority (75-92%) expected services provided in a collaborative practice to differ from those provided in a noncollaborative practice. Women making their first visit to a collaborative practice expected quicker appointments, more time with the provider, more health information, and more specific diet information than did women who had previously been seen in such a practice. There were minimal differences in comfort levels when discussing issues of sexuality and physical and sexual abuse in either public or private settings with physicians or non-physicians. CONCLUSIONS: Patients in this survey were accepting of the concept of collaborative practice and felt that it offered quicker appointments, more time with the provider, more health information, and more specific diet information than did physician-only practices.

Comparison of RigiScan and sleep laboratory nocturnal penile tumescence in the diagnosis of organic impotence.

PURPOSE: We evaluated the relative use of RigiScan measurement of radial rigidity compared to sleep laboratory measurement of axial rigidity and trained observer determination of erectile function in the diagnosis of organic impotence. MATERIALS AND METHODS: A total of 28 patients underwent simultaneous 2-night formal sleep laboratory nocturnal penile tumescence and RigiScan monitoring. Standard normal values for radial rigidity and axial rigidity were tested for accuracy in predicting normal nocturnal penile tumescence compared to trained observer determination of the adequacy of an erection for penetration. RESULTS: RigiScan tip measurements correlated poorly with buckling pressure, while base measurements strongly correlated (p = 0.0005). Observer determination of a functional erection was strongly associated with tip (p = 0.002), base (p = 0.0005) and buckling pressure measurements (p = 0.0005). Using observer determination as the gold standard receiver operating curves were generated to select RigiScan base and buckling pressure measurements that predicted functional erections with the highest sensitivity and specificity. CONCLUSIONS: RigiScan is a useful tool for measuring nocturnal penile tumescence. However, base measurements are more accurate than tip measurements for evaluating erectile function. The currently accepted level of rigidity used to define a normal erection (70% or greater) overestimates organic erectile dysfunction.

Acute effects of transdermal nicotine on sleep architecture, snoring, and sleep-disordered breathing in nonsmokers.

Previous research has suggested that nicotine may be therapeutically useful in the treatment of sleep-disordered breathing. The development of transdermal nicotine delivery systems has allowed us to test the overnight effectiveness of nicotine. Twenty nonsmoking subjects (10 men, 10 women) were recruited on the basis of a history of habitual snoring that was confirmed by overnight laboratory monitoring. Subjects were then randomized (double-blind crossover design) to receive either placebo or an active patch that delivers 11 mg of nicotine over a 24-h period. Patches were applied at 6 P.M. and removed at 6 A.M. the following morning, at which time venous blood was obtained for determination of serum nicotine concentrations. Polysomnography was performed using standard techniques to assess sleep architecture and sleep-disordered breathing. Snoring was monitored with a sound-level meter and quantitatively analyzed to determine the snoring index (SI) (number of snores per hour of sleep) and mean and maximum snoring intensities. The age of the subjects was 46.9 +/- 11.4 yr (mean +/- SD) and their mean body mass index (BMI) 33.3 +/- 4.6 kg/m2. A mean nicotine level was nondetectable with placebo and 7.8 +/- 2.3 ng/ml with wearing of an active patch. Nicotine decreased total sleep time (TST) by 33 min (p < or 0.01), sleep efficiency from 89.7 to 83.5% (p < or = 0.01), and percent rapid eye movement (REM) sleep from 18.8 to 15.1% (p < or = 0.01), and prolonged initial sleep latency (ISL) from 6.7 to 18.2 min (p < or = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

A geographic analysis of non-Russian minorities in Russia and its ethnic homelands.

"The paper...analyzes the characteristics of 27 million non-Russians who constituted 18 percent of the population of the Russian Federation and its 31 ethnic homelands in 1989. Utilizing data from all Soviet censuses (from 1926), it reviews long-term historical trends; growth patterns related to urban-rural differences, family size, regional contrasts in rates of natural increase, and specific ethnic traits; migration patterns; factors influencing language shifts to the Russian; effect of location inside or outside homeland; and the influences of transportation, cities, and economic development in individual homelands."

The new Russian minorities: a statistical overview.

The author "presents a succinct review of the newly constituted Russian minorities situated in the former Soviet republics. Based on census data series (1897 to 1989) and original computations, the paper covers location (highest proportion of Russians in Kazakhstan, Latvia, and Estonia), concentration (predominantly urban), occupational structure (largely in industry and science), and related data on issues such as language affinities and migration."

The birth control pill revisited.

The evolution of oral contraceptives is summarized in this chapter. The social context into which the birth control pill was introduced, early and recent formulations of the pill, side effects, and the identification of serious complications of taking the pill are presented. The role of the nurse as a health educator of women and the responsibility of nurses to assist patients to make informed decisions about their reproductive function are emphasized. The outlook for future research and development of alternative forms of contraception is discussed.

The influence of ankle strapping on wobbleboard performance, before and after exercise.

Twenty four uninjured female volunteers (mean age = 19.6 years) were utilised to study the effect of modified Gibney ankle strapping on proprioception before, during and after exercise, by measuring performance on an instrumented wobbleboard. Following a familiarisation session, testing was conducted on two occasions using a crossover research design, utilising strapped and unstrapped conditions. The time in contact, the number of contacts and the average time in contact that the wobbleboard made with a metal baseplate under the wobbleboard were recorded during a ten second test duration. Tests were conducted at the times of 0, 5, 10 and 15 minutes of a standardised exercise regime performed by the subjects. Results revealed that strapping had no significant effect on wobbleboard performance. Since the wobbleboard is widely accepted as a method of training as well as a clinical assessment of ankle proprioception, it could be inferred that strapping had no effect on proprioception before, during or after exercise.

Influence of sleep state on CO2 responsiveness. A study of the unloaded respiratory pump in humans.

We measured the ventilatory recruitment threshold for CO2 (RT) during wakefulness, nonrapid eye movement sleep (NREM), and rapid eye movement sleep (REM) in eight patients with respiratory failure. Because the lungs were mechanically ventilated during the RT measurements, we were able to define the effects of arousal state on the chemoresponsiveness of the unloaded respiratory system. Ventilator settings were held constant in each patient, assuring that mechanoreceptor input to the respiratory controller remained the same during all measurements. RT increased from 38 +/- 6 mm Hg during relaxed wakefulness to 42 +/- 8 mm Hg during NREM sleep (p less than or equal to 0.01), consistent with a blunting of chemoresponsiveness during sleep. In five subjects we were able to measure RT during REM sleep also. In four of them, REM RT exceeded the wakefulness measurement by at least 3 mm Hg. The remaining patient showed no demonstrable changes in RT during either sleep state. We conclude that the loss of a wakefulness stimulus contributes to sleep-induced hypercarbia in humans.

An ultrastructural comparison of neuromuscular junctions in normal and developmentally arrested Rana pipiens larvae: limited maturation in the absence of metamorphosis.

Neuromuscular junctions in the rectus abdominis muscles of normal and developmentally arrested Rana pipiens larvae were studied with freeze fracture and conventional electron microscopy to determine whether structural aspects of junctional maturation depend on metamorphosis. Comparison was made between junctions in premetamorphic larvae 1-3 months old and junctions in larvae that had remained in premetamorphosis for more than a year (more than four times as long as normal). In most respects, junctions from the two groups of larvae were similar. Unlike adult junctions, nerve-muscle contacts in both larval groups were pleomorphic and often involved more than one neuronal process; Schwann cell processes very rarely extended between nerve and muscle. Active zone structure ranged from total disorganization to an adult pattern of highly ordered double rows of particles aligned over junctional folds. Only quantitative analysis revealed differences between junctions in old and young larvae. The older larvae had fewer nerve-muscle contact sites involving multiple neuronal elements and a higher ratio of active zone length to presynaptic membrane area, although the mean active zone length was the same in the two groups. The results indicate that the maturation of junctional shape, the branching pattern of the axons, and the relationship of presynaptic axons to Schwann cells must be directly or indirectly dependent on the hormonal or behavioral changes associated with metamorphosis.

Chest wall motion in sleep apnea.

Patterns of rib cage (RC) and abdomen (ABD) motion obtained from a respiratory inductive plethysmograph were studied during disordered breathing events - obstructive apnea, obstructive hypopnea, mixed apnea, and central apnea - in 54 patients with sleep apnea. The type of disordered breathing event was verified by esophageal pressure and bias-flow mask recordings. Obstructive apnea occurred to a variable extent in all patients and was characterized by stereotyped paradoxical motion of the RC or ABD or both in 49 patients (91%). There was no paradox in 2 patients with "feeble" inspiratory effort during obstructions and in 3 patients with normal inspiratory effort during obstructed breaths. The more obese patients displayed paradox of the ABD rather than of the RC. Paradox did not occur in central apnea or in the central component of mixed apnea. Obstructive hypopnea was characterized by paradox during part of the breath. We conclude that RC and ABD motion can adequately characterize apnea in most patients and thus avoid invasive monitoring techniques that can adversely affect sleep. However, if chest wall motion suggests that all apneas are central, a direct measurement of respiratory effort is necessary to exclude obstruction.