Parametric Extension of the Classical Exposure-Schedule Theory for Angle-Multiplexed Photorefractive Recording over Wide Angles.

The gradual reorientations in crystal geometry encountered during angle-multiplexed holographic recording with obliquely incident recording beams can create significant parametric exposure-time and recording-angle dependencies in both grating writing- and erasure-time constants. We present a parametric extension of the classically derived backward-recursion algorithm that compensates for the intermingling effects of recording geometry, writing-beam intensity variations, and unique crystal behavior. We present experimental data for a sequence of 301 holograms recorded with the goal of equal hologram strength and, separately, the same sequence recorded with the goal of equal hologram reconstruction intensity-which are different cases for a steeply incident readout beam.

Progression of the culprit lesion in unstable coronary artery disease with warfarin and aspirin versus aspirin alone: preliminary study.

OBJECTIVES: This study assessed whether combination therapy with aspirin and warfarin for 10 weeks reduces the risk of progression or reocclusion of the unstable coronary artery lesion. BACKGROUND: Reocclusion of the culprit coronary artery occurs in up to one third of patients during the 3 months after myocardial infarction (MI) or unstable angina and is associated with increased morbidity and mortality. METHODS: Fifty-seven patients presenting with unstable angina or MI who had an identifiable culprit lesion at coronary angiography were randomized in double-blind manner to receive warfarin (target international normalized ratio [INR] 2.0 to 2.5) or placebo in addition to aspirin (150 mg daily). Changes in the culprit lesion were assessed by quantitative angiography in 50 patients after 10 weeks of therapy or after a clinical event. Progression of the culprit lesion was defined as a decrease in minimal lumen diameter > 0.4 mm or a new total occlusion. Regression was defined as an increase in minimal lumen diameter > 0.4 mm. RESULTS: In subjects randomized to receive warfarin, the culprit lesion was less likely to progress (1 [4%] vs. 8 [33%]) and more likely to regress (5[19%] vs. 2[9%]) than in subjects receiving placebo (p = 0.02). Recurrent MI or a new occlusion at angiography occurred in 2 (7%) of 29 patients receiving warfarin versus 11 (39%) of 28 patients receiving placebo (p = 0.005). CONCLUSIONS: In patients with an acute coronary syndrome, combined therapy with aspirin and warfarin with a target INR of 2.0 to 2.5 for 10 weeks reduces the risk of progression or reocclusion of the culprit coronary lesion.

Carbon arc solar simulator.

Measurements of the spatial, spectral, and temporal characteristics of the beam irradiance of a carbon arc solar simulator are reported. Pyroelectric radiometer measurements of total irradiance and spectroradiometer measurements of spectral irradiance are presented. The solar simulator spectral irradiance is compared with the ASTM standard AM 1.5 global solar spectral irradiance over a wavelength region of 300-2500 nm. The suitability of the solar simulator for laser receiver testing is discussed.

Reflective membrane optical scintillator: design and characterization.

Amplitude distributions produced by a novel reflective membrane optical scintillator (RMOS) showed excellent statistical agreement with experimental field data taken from actual atmospheric measurements. Laboratory simulated atmospheric turbulence using RMOS was found to have a log-normal amplitude distribution. This included two test cases representing subsets of real weak turbulence and moderate turbulence regimes.

Amerlex free triiodothyronine and free thyroxine levels in normal pregnancy.

Free triiodothyronine (FT3) and free thyroxine (FT4) were measured in 159 women during normal pregnancy and compared with non-pregnancy reference ranges for these hormones. FT3 values fell from the reference level of 6.34 (SD 1.06) pmol/l to 3.87 (SD 0.54) pmol/l in the 3rd trimester; corresponding figures for FT4 were: reference 16.92 (SD 2.97) pmol/l, 3rd trimester 11.29 (SD 2.01) pmol/l. There were no significant changes in the 1st trimester; 4% and 69% of FT3 results in the 2nd and 3rd trimesters respectively fell below the reference range of mean +/- 2 SD. The corresponding findings for FT4 were 4% and 42%. FT3 correlated reasonably well with total T3 (r = 0.90) and was acceptably precise (within-batch CV 2.1% at 5.6 pmol/l, between-batch CV between 3.1% and 4.7% at six levels).

Sensitive assay, based on hydroxy fatty acids from lipopolysaccharide lipid A, for Gram-negative bacteria in sediments.

Biochemical measures have provided insight into the biomass and community structure of sedimentary microbiota without the requirement of selection by growth or quantitative removal from the sediment grains. This study used the assay of the hydroxy fatty acids released from the lipid A of the lipopolysaccharide in sediments to provide an estimate of the gram-negative bacteria. The method was sensitive to picomolar amounts of hydroxy fatty acids. The recovery of lipopolysaccharide hydroxy fatty acids from organisms added to sediments was quantitative. The lipids were extracted from the sediments with single-phase chloroform-methanol extraction. The lipid-extraction residue was hydrolyzed in 1 N HCl, and the hydroxy fatty acids of the lipopolysaccharide were recovered in chloroform for analysis by gas-liquid chromatography. This method proved to be about fivefold more sensitive than the classical phenol-water or trichloroacetic acid methods when applied to marine sediments. By examination of the patterns of hydroxy fatty acids, it was also possible to help define the community structure of the sedimentary gram-negative bacteria.

Estimations of uronic acids as quantitative measures of extracellular and cell wall polysaccharide polymers from environmental samples.

The extracellular polysaccharide polymers can bind microbes to surfaces and can cause physical modification of the microenvironment. Since uronic acids appear to be the components of these extracellular films that are most concentrated in a location outside the cell membrane, a quantitative assay for uronic acids was developed. Polymers containing uronic acids are resistant to quantitative hydrolysis, and the uronic acids, once released, form lactones irreproducibly and are difficult to separate from the neutral sugars. These problems were obviated by the methylation of the uronic acids and their subsequent reduction with sodium borodeuteride to the corresponding alcohol while they were in the polymer and could not form lactones. This caused the polymers to lose the ability to adhere to their substrates, so they could be quantitatively recovered. The hydrolysis of the dideuterated sugars was reproducible and could be performed under conditions that were mild enough that other cellular and extracellular polymers were not affected. The resulting neutral sugars were readily derivatized and then were separated and assayed by glass capillary gas-liquid chromatography. The dideuterated portion of each pentose, hexose, or heptose, identified by combined capillary gas-liquid chromatography and mass spectrometry, accurately provided the proportion of each uronic acid in each carbohydrate of the polymer. Examples of the applications of this methodology include the composition of extracellular polymers in marine bacteria, invertebrate feeding tubes and fecal structures, and the microfouling films formed on titanium and aluminum surfaces exposed to seawater.

Tooth attrition and continuing eruption in a Romano-British population.

Cement-enamel junction to alveolar crest (CEJ-AC) distances were measured in Romano-British skulls. Measurements were also made of attrition patterns. The patterns of the two measurements were similar in each group, suggesting that teeth continued to erupt and CEJ-AC alone is misleading as a measurement of bone loss and may not relate to the extent of chronic inflammatory periodontal disease. Estimated bone loss was minimal, confirming that measurements of this nature on dried skulls should only be related to periodontal conditions with caution.

Trial of a centralized IgE allergy service to general practitioners in a rural area.

We describe a pilot study of a community IgE service which serves a large rural area and is centred on the biochemistry laboratory and allergy clinic of a district general hospital. The service has proved useful because in many cases it has made attendance at an outpatient department unnecessary. The results appear to be reliable and have provided the general practitioners with additional knowledge of their patients. Other benefits included the investigation of larger numbers of patients, the performance of fewer skin tests and greater precision in test results because the tests were carried out by one investigator under standard conditions.

Dietary allergy and specific IgE in ulcerative colitis.

Previous authors have considered that allergy to certain foodstuffs may play an important role in the aetiology of ulcerative colitis, but immunological evidence for dietary allergy in ulcerative colitis is inconclusive. A study is reported of 22 patients with ulcerative colitis, with matched controls, in whom total serum IgE and specific IgE to certain foodstuffs have been estimated by the Phadebas PRIST and RAST (Pharmacia) techniques. Allergens tested were egg-white, milk, wheat, rye, oat, fish (cod) and peanut. There was no significant difference in the total serum IgE levels and the food specific IgE activity between the two groups.

D-Lyxose as a substrate for Streptomyces D-xylose isomerase.

Results are presented which show that the D-xylose isomerases present in Streptomyces olivaceus and Streptomyces phaeochromogenes NRRL B-3559 are incapable of utilizing D-lyxose as a substrate. The implications of these findings as related to the use of D-lyxose in the selection of constitutive mutants are discussed.

Prognosis in schizophrenia. Prognostic predictors and outcome.

Eighty-eight of 92 first-admission schizophrenics from 1963, an incidence by first admission cohort, were followed up in 1974 and 1975. Epidemiologically the sample was more comparable to lower European rates and expectancy rather than to higher American figures. Prior to follow-up, factors said to predict outcome were scored. This prognostic information was complete for 79 cases. Outcome was measured on a variety of criteria. The patients fell into a "poor prognosis" group based on the prognostic indicators, which were of little value in predicting prognosis within this group. However, patients who received extensive service during the follow-up period had poorer outcomes. Outcome was better than in most earlier studies of schizophrenia, but similar to that in some other recent studies of first-admission patients; also, the use of phenothiazines, short-term hospitalization, and community services may play a part. The failure of prognostic indicators to predict more than about 25% of the outcome variance for this group of "poor prognosis" patients supports the viewpoint that "good" and "poor" prognosis schizophrenia are two different entities.

Prognosis in schizophrenia. A ten-year follow-up of first admissions.

Eighty-eight of 92 first admission schizophrenics from 1963, being an incidence by first admission cohort, were followed up between 1974 and 1975. Fifty-eight percent were reported as showing no social or intellectural deficit, and only 8% were unremitting institutionalized, with 51% being considered as having normal economic productivity, and 69% with a good or fair social adjustment. Despite difficulties in comparison, birth, marriage, and divorce rates appear to be not very different from those for the general population, although the percentage of married patients is lower. Deaths would seem greater than expected. Possible reasons for the improved prognosis in schizophrenia are considered to be short initial hospitalization, almost universal use of phenothiazines, use of developing community services (social and psychiatric), and generally good econimic conditions.