The design of a line velocity interferometer for any reflector for inertial confinement experiments on the Z-machine

A line VISAR (Velocity Interferometer System for Any Reflector) has been designed and commissioned at the Sandia National Laboratory's Z-machine. The instrument consists of an F/2 collection system, beam transport, and an interferometer table that contains two Mach-Zehnder type interferometers and an eight channel Gated Optical Imaging (GOI) system. The VISAR probe laser operates at the 532 nm wavelength, and the GOI bandpass is 540-600 nm. The output of each interferometer is passed to an optical streak camera with four selectable sweep speeds. The system is designed with three interchangeable optics modules to select a full field of view of 1 mm, 2 mm, or 4 mm. The optical beam transport system connects the target image plane to the interferometers and the gated optical imagers. The target is integrated into a sacrificial final optics assembly that is integral to the transport beamline.

Synthesis and Growth of Gallium Nitride by the Chemical Vapor Reaction Process (CVRP)

A new process for synthesis and bulk crystal growth of GaN is described. GaN single crystal c-plane platelets up to 9mm by 2mm by 100μm thick have been grown by the Chemical Vapor Reaction Process (CVRP). The reaction between gallium and a nitrogen precursor is produced by sublimation of solid ammonium chloride in a carrier gas, which passes over gallium at a temperature of approximately 900°C at near atmospheric pressures. Growth rates for the platelets were 25-100 μm/hr in the hexagonal plane. Seeded growth in the c-direction was also accomplished by re-growth on previously grown c-plane platelets. The crystals were characterized by X-ray diffractometry, atomic force microscopy, secondary ion mass spectrometry, inert gas fusion, and room temperature Hall effect and resistivity measurements.

High Quality Hydrothermal ZnO Crystals

Zinc Oxide crystals have historically been grown in hydrothermal autoclaves with a basic mineralizer; however, doubts have been raised about the quality of such crystals because they have often exhibited large x-ray rocking curve widths and low photoluminescence (PL) yield with large linewidths. Several ZnO crystals were grown hydrothermally and sliced parallel to the c-plane. This resulted in opposite surfaces (the C+ and C−) exhibiting pronounced chemical and mechanical differences. Different surface treatments were investigated and compared by PL both at room temperature and liquid helium temperatures, and by double axis X-ray rocking curve measurements. The high quality of hydrothermally-grown ZnO is substantiated by the narrow rocking curve widths and sharp PL peaks obtained. A critical factor in obtaining these results was found to be surface preparation.

Widely tunable midinfrared difference frequency generation in orientation-patterned GaAs pumped with a femtosecond Tm-fiber system

We demonstrate a midinfrared source tunable from 6.7 to 12.7 μm via difference frequency generation (DFG) in orientation-patterned GaAs, with 1.3 mW average output power. The input pulses are generated via Raman self-frequency shift of a femtosecond Tm-doped-fiber laser system in a fluoride fiber. We numerically model the DFG process and show good agreement between simulations and experiments. We use this numerical model to show an improved design using longer pump pulses.

Voyager 2 in the uranian system: imaging science results

Voyager 2 images of the southern hemisphere of Uranus indicate that submicrometersize haze particles and particles of a methane condensation cloud produce faint patterns in the atmosphere. The alignment of the cloud bands is similar to that of bands on Jupiter and Saturn, but the zonal winds are nearly opposite. At mid-latitudes (-70 degrees to -27 degrees ), where winds were measured, the atmosphere rotates faster than the magnetic field; however, the rotation rate of the atmosphere decreases toward the equator, so that the two probably corotate at about -20 degrees . Voyager images confirm the extremely low albedo of the ring particles. High phase angle images reveal on the order of 10(2) new ringlike features of very low optical depth and relatively high dust abundance interspersed within the main rings, as well as a broad, diffuse, low optical depth ring just inside the main rings system. Nine of the newly discovered small satellites (40 to 165 kilometers in diameter) orbit between the rings and Miranda; the tenth is within the ring system. Two of these small objects may gravitationally confine the e ring. Oberon and Umbriel have heavily cratered surfaces resembling the ancient cratered highlands of Earth's moon, although Umbriel is almost completely covered with uniform dark material, which perhaps indicates some ongoing process. Titania and Ariel show crater populations different from those on Oberon and Umbriel; these were probably generated by collisions with debris confined to their orbits. Titania and Ariel also show many extensional fault systems; Ariel shows strong evidence for the presence of extrusive material. About halfof Miranda's surface is relatively bland, old, cratered terrain. The remainder comprises three large regions of younger terrain, each rectangular to ovoid in plan, that display complex sets of parallel and intersecting scarps and ridges as well as numerous outcrops of bright and dark materials, perhaps suggesting some exotic composition.

High-power source of THz radiation based on orientation-patterned GaAs pumped by a fiber laser

We demonstrate a new source of frequency-tunable THz wave packets based on parametric down-conversion process in orientation-patterned GaAs (OP-GaAs) that produces muW-level THz average powers at the repetition rate of 100 MHz. The OP-GaAs crystal is pumped by a compact all-fiber femtosecond laser operating at the wavelength of 2 mum. Such combination of fiber laser and OP-GaAs technologies promises a practical source of THz radiation which should be suitable for many applications including imaging and spectroscopy.

Optical parametric generation of a mid-infrared continuum in orientation-patterned GaAs

We have generated an ultrabroad mid-infrared continuum by using single-pass optical parametric generation (OPG) in orientation-patterned GaAs (OP-GaAs). The spectrum spans more than an octave, from 4.5 to 10.7 microm, measured 20 dB down from the peak. The 17.5 mm long, 0.5 mm thick, all-epitaxially-grown OP-GaAs sample with a 166.6-microm quasi-phase-matching period was pumped with 3.1-3.3 microm wavelength, 1 ps pulses up to 2 microJ in energy. The OPG threshold was observed at 55 nJ pump energy with the pump polarized along the [111] crystal direction. The slope efficiency near threshold was 51%, and the external conversion efficiency was as high as 15%.

Communicable disease case entry using PDAs and public wireless networks

Concerns about detecting and responding to attacks with biowarfare agents have resulted in the development of deployable case reporting systems, e.g. RSVP. We implement a proof of concept web-based information system to be used securely from personal digital assistants over public wireless networks, by public health field workers for routine and emergent case reporting. The system collects data for a local health jurisdiction, provides content- and event-based notification, and forwards case reports to the Colorado State communicable disease reporting system (CEDRS). We believe this demonstrates a useful integration of portable and web-based technologies with public health practice.

National Pharmaceutical Stockpile drill analysis using XML data collection on wireless Java phones

This study describes an informatics effort to track subjects through a National Pharmaceutical Stockpile (NPS) distribution drill. The drill took place in Seattle on 1/24/2002. Washington and the State Department of Health are among the first in the nation to stage a NPS drill testing the distribution of medications to mock patients, thereby testing the treatment capacity of the plan given a post-anthrax exposure scenario. The goal of the Public Health Informatics Group at the University of Washington (www.phig.washington.edu) was to use informatics approaches to monitor subject numbers and elapsed time. This study compares accuracy of time measurements using a mobile phone Java application to traditional paper recording in a live drill of the NPS. Pearson correlation = 1.0 in 2 of 3 stations. Differences in last station measurements can be explained by delay in recording of the exit time. We discuss development of the application itself and lessons learned. (MeSH Bioterrorism, Informatics, Public Health)

IML: An image markup language

Image Markup Language is an extensible markup language (XML) schema used to describe both image metadata and annotations. It describes both data pertaining to an entire image, and data that are tied to specific regions or features of the image. Developed for a specific domain in Medical Education, this pa-per describes extensions to take advantage of the Dublin Core metadata standard, and of an XML schema for vector graphics representation. We have developed a prototype system of open source tools implementing an authoring system, a client system, and an image annotation database which can be queried though the Web.

A decade of experience with the primary pull-through for hirschsprung disease in the newborn period: a multicenter analysis of outcomes

OBJECTIVE

To determine whether use of a primary pull-through would result in equivalent perioperative and long-term complications compared with the two-stage approach.

SUMMARY BACKGROUND DATA

During the past decade, the authors have advanced the use of a primary pull-through for Hirschsprung disease in the newborn, and preliminary results have suggested excellent outcomes.

METHODS

From May 1989 through September 1999, 78 infants underwent a primary endorectal pull-through (ERPT) procedure at four pediatric surgical sites. Data were collected from medical records and a parental telephone interview (if the child was older than 3 years) to assess stooling patterns. A similar group of patients treated in a two-stage fashion served as a historical control.

RESULTS

Mean age at the time of ERPT was 17.8 days of life. Comparing primary ERPT with a two-stage approach showed a trend toward a higher incidence of enterocolitis in the primary ERPT group compared with those with a two-stage approach (42.0% vs. 22.0%). Other complications were either lower in the primary ERPT group or similar, including rate of soiling and development of a bowel obstruction. Median number of stools per day was two at a mean follow-up of 4.1 +/- 2.5 years, with 83% having three or fewer stools per day.

CONCLUSIONS

Performance of a primary ERPT for Hirschsprung disease in the newborn is an excellent option. Results were comparable to those of the two-stage procedure. The greater incidence of enterocolitis appears to be due to a lower threshold in diagnosing enterocolitis in more recent years.

Fecal Incontinence Quality of Life Scale: quality of life instrument for patients with fecal incontinence

PURPOSE

This goal of this research was to develop and evaluate the psychometrics of a health-related quality of life scale developed to address issues related specifically to fecal incontinence, the Fecal Incontinence Quality of Life Scale.

METHODS

The Fecal Incontinence Quality of Life Scale is composed of a total of 29 items; these items form four scales: Lifestyle (10 items), Coping/Behavior (9 items), Depression/Self-Perception (7 items), and Embarrassment (3 items).

RESULTS

Psychometric evaluation of these scales demonstrates that they are both reliable and valid. Each of the scales demonstrate stability over time (test/retest reliability) and have acceptable internal reliability (Cronbach alpha >0.70). Validity was assessed using discriminate and convergent techniques. Each of the four scales of the Fecal Incontinence Quality of Life Scale was capable of discriminating between patients with fecal incontinence and patients with other gastrointestinal problems. To evaluate convergent validity, the correlation of the scales in the Fecal Incontinence Quality of Life Scale with selected subscales in the SF-36 was analyzed. The scales in the Fecal Incontinence Quality of Life Scale demonstrated significant correlations with the subscales in the SF-36.

CONCLUSIONS

The psychometric evaluation of the Fecal Incontinence Quality of Life Scale showed that this fecal incontinence-specific quality of life measure produces both reliable and valid measurement.

Patient and surgeon ranking of the severity of symptoms associated with fecal incontinence: the fecal incontinence severity index

PURPOSE

The purpose of this research was to develop and evaluate a severity rating score for fecal incontinence, the Fecal Incontinence Severity Index.

METHODS

The Fecal Incontinence Severity Index is based on a type x frequency matrix. The matrix includes four types of leakage commonly found in the fecal incontinent population: gas, mucus, and liquid and solid stool and five frequencies: one to three times per month, once per week, twice per week, once per day, and twice per day. The Fecal Incontinence Severity Index was developed using both colon and rectal surgeons and patient input for the specification of the weighting scores.

RESULTS

Surgeons and patients had very similar weightings for each of the type x frequency combinations; significant differences occurred for only 3 of the 20 different weights. The Fecal Incontinence Severity Index score of a group of patients with fecal incontinence (N = 118) demonstrated significant correlations with three of the four scales found in a fecal incontinence quality-of-life scale.

CONCLUSIONS

Evaluation of the Fecal Incontinence Severity Index indicates that the index is a tool that can be used to assess severity of fecal incontinence. Overall, patient and surgeon ratings of severity are similar, with minor differences associated with the accidental loss of solid stool.

Efficacy of anterior gastric fundoplication in the treatment of gastroesophageal reflux in infants and children

Anterior gastric fundoplication (AGF) has been performed at the University of Michigan since 1988. To objectively evaluate the long-term efficacy of the AGF, the authors performed a study of children who had undergone AGF between June 1988 and June 1990 (n = 46). Six of them died of unrelated causes. Twenty-two consented to follow-up evaluation that included parental interview, physical examination, upper gastrointestinal series (UGI), 24-hour esophageal pH probe monitoring (EpH), and a liquid-phase gastric emptying study. Twenty patients (74%) remained asymptomatic, and only one child required reoperation. Four asymptomatic patients exhibited gastroesophageal reflux (GER) by UGI, and three others by EpH. Three children were noted to have delayed gastric emptying. These results compare favorably with data previously reported from this institution of a 5-year follow-up of children after Nissen fundoplication. There is a trend toward improved efficacy (87% v 74%; P = .12), decreased reoperation rate (4% v 14%; P = .11), and less severe complications. The present study shows that AGF is effective treatment for GER when evaluated by objective studies and is comparable in therapeutic efficacy and safety to the Nissen fundoplication.

Problems and issues in community mental health service delivery in the 1990s

With the repeal of the Mental Health Systems Act by the Reagan administration in 1980, the amount of federal dollars allocated to community mental health agencies declined. Perlman and Hartman (1982) surveying mental health administrators' and professionals' perceptions on the major issues to be faced in the 1980s, found that budget reductions were to have the greatest impact on mental health service delivery. To explore problems and issues in mental health service delivery in the 1990s, 272 mental health administrators in county level, public sector organizations from Wisconsin and Michigan were surveyed. Budget effects on service, staff and administration are discussed.

Intra-aortic balloon cardiac assist: complication rates for the surgical and percutaneous insertion techniques

A retrospective study was performed to evaluate complications with the two most common intra-aortic balloon pump (IABP) insertion techniques. During a nine year period, 202 patients (51 women, 151 men) underwent IABP cardiac assist utilizing the arteriotomy surgical (103 balloons) and percutaneous (99 balloons) insertion techniques. Complications, including asymptomatic loss of pedal pulse, vascular-symptomatic, infection, or balloon rupture occurred in 22.8 per cent of patients. Of the 54 complications, 13 (24%) were asymptomatic loss of pedal pulse, 36 (66.7%) were vascular symptomatic, three (5.5%) were infection, and two (3.7%) were balloon malfunctions. The overall complication rates were 16/103 (15.5%) and 38/99 (38.3%) for the surgical and percutaneous methods, respectively (P = 0.007). Thirty two per cent (33/103) of the patients receiving IABP surgically and 24 per cent (24/99) of those receiving IABP percutaneously died in the hospital (P = 0.34); no death was directly attributable to IABP. The number of patients requiring surgical intervention or removal was not significantly different between the surgical and percutaneous methods (9 versus 18%, P = .06). While the method of IABP insertion did not significantly alter hospital mortality, a significantly greater complication rate was observed with percutaneous insertion (P = .007). This was particularly relevant to complications occurring at the time of removal of IABP.

Quantitation of human immunoglobulin G and albumin in electroimmunodiffusion gels containing ionic and nonionic detergents

Quantitation of human immunoglobulin G (IgG) and albumin by agarose electroimmunodiffusion is influenced by the incorporation of ionic and nonionic detergents in the gel. The highest concentrations of each detergent at which human IgG and albumin determinations could be performed without perturbing the quantitations were 4% Triton X-100, 4% Tween 80, 1% NP-40, 0.5% sodium deoxycholate (SDOC), 0.5% Zwittergent, and 0.1% sodium dodecyl sulfate (SDS), and mixtures of Triton X-100, SDOC, and SDS. These detergent combinations all resulted in greater perturbations of albumin quantitation than of IgG. Immunoprecipitation of human IgG was quantitated in the absence and presence of Triton X-100, Zwittergent, and SDS. SDS was shown to cause nonspecific precipitation, whereas below 1% Triton X-100 or 0.5% Zwittergent no effects upon the immunoprecipitations were observed.

Controlled evaluation of fenbendazole as a bovine anthelmintic

Calves experimentally infected with Haemonchus, Ostertagia, and Cooperia, and to lesser degrees with Trichostrongylus, Oesophagostomum, Nematodirus, and Bunostomum were used in a controlled experiment to record the anthelmintic efficacy of a benzimidazole compound methyl 5-(phenylthio)-2-benzimidazolecarbamate at dosage levels of 3.5, 5, and 7.5 mg/kg bodyweight. With the 3 dosages, reductions of Haemonchus were 96.7, 99.2, and 99.8%; of Ostertagia, 97.2, 97.2, and 99.5%; and of Cooperia, 99.9, 99.9, and 99.9%. Pronounced reductions were also recorded for Trichostrongylus, Nematodirus, Oesophagostomum, Trichuris, and Capillaria, but these populations were too numerically small or too unevenly distributed within the control groups to be given much emphasis. The experimental parasitic populations which developed in the 10 control calves amounted to 91, 763 worms (total).

Thrombocytopenia and carcinoma

The cases of two patients suffering from carcinoma of the lung and severe thrombocytopenia are described. The thrombocytopenia was probably due to an immune mechanism and not to marrow replacement by carcinoma or consumption coagulopathy. It is suggested that patients in the older age group presenting with thrombocytopenia may have occult carcinoma.