Quantitative comparison of volatile compounds among sevenMedicago spp. accessions

Previous research identified the presence of unique semivolatile compounds in alfalfa weevil (Hypera postica Gyllenhal) (AW) -resistantMedicago accessions. These compounds may impart repellency to AW in alfalfa (Medicago sativa L.). The objective of our study was to analyze within- and between-population variation for four of these unique semivolatile compounds across eglandular and glandular-hairedMedicago accessions. SevenMedicago accessions were evaluated under greenhouse conditions in an experiment arranged as randomized complete blocks with four replicates. Volatile compounds were extracted via supercritical fluid extraction and then quantitatively analyzed for levels of 2,7-dimethyl, 2,6-octadienol;cis-geraniol; 1,(E)-8,(Z)-10-tetradecatriene; and 1-hepten-3-ol. Significant difference (P<0.05) among entries were observed for 2,7-dimethyl,2,6-octadienol;cis-geraniol; 1, and (E)-8,(Z)-10-tetradecatriene. These compounds were found only in glandularhaired accessions. There were no significant differences in levels of 1-hepten-3-ol. Our findings demonstrate that the genetic incorporation of 2,7-dimethyl, 2,6-octadienol;cis-geraniol; 1, and (E)-8,(Z)-10-tetradecatriene into cultivated alfalfa will require interspecific crossing. Alfalfa weevil behavioral tests using these compounds must be conducted prior to such crosses in order to ascertain the efficacy of repellency by these compounds.     

Thin-film polariser for Ti:LiNbO3 waveguides at ?=1.3?m

Thin-film polarisers using a dielectric buffer layer and a metallic overlay on Ti:LiNbO3 channel waveguides for ? = 1.3 ?m have been designed and fabricated. The TM mode extinction ratio better than 35 dB and negligible TE mode excess losses have been measured with Si3N4/Al polarisers 2 mm long.     

Microbreak length, performance, and stress in a data entry task

The effects of brief rest pauses on performance and well-being were evaluated for a highly repetitive, data entry task. Experienced data entry operators (N = 20) performed the task in a two-day experiment in a simulated office environment. Each day was divided into six, 40-min work periods. Subjects took a brief rest pause at the workstation (microbreak) in the middle of each work period. Subjects were instructed to terminate this microbreak when ready to resume work. Keystroke rate, error rate, correction rate, heart rate and heart rate variability were scored for each half of the work period. In addition, mood states before and during the work period were assessed. Microbreaks were found to average 27.4 s in duration. High ratings of fatigue and boredom during the work period were associated with longer microbreaks, suggesting that the break period was self-adjusted relative to mood state. In addition, correction rate and heart rate were lower following long microbreaks, implying that the degree of recovery was linked to the length of the microbreak. Comparison of keystroke output and correction rate before and after the microbreak, however, revealed that performance worsened after the microbreak, suggesting that subjects terminated microbreaks before complete recovery could occur.     

Distribution and carbohydrate structures of high molecular weight glycoproteins, MUC1 and MUCX, in bovine milk

High molecular weight glycoproteins, MUC1 and MUCX, originating from bovine milk, were compared with regard to their distribution in milk fat and skim milk fractions and for presence of carbohydrate structures. Polymorphic MUC1, which migrated into 6% resolving SDS-PAGE gels, was found in both milk fat globule membrane and skim milk phases of bovine milk. In contrast, MUCX, appearing as a non-polymorphic single band in 3% polyacrylamide stacking gels, was present only in the skim milk fraction. Peptide-N-glycosidase F digestion studies indicated that MUC1 and MUCX possessed N-glycans with MUC1 containing more N-glycans than MUCX. Exoglycosidase digestion studies revealed the existence of abundant terminal sialic acid residues in both MUC1 and MUCX. Lectin-binding studies showed that MUCX likely possessed more complex carbohydrate structures than MUC1. The complex carbohydrate structures carried by both MUC1 and MUCX suggest that they may have potential to bind a wide spectrum of pathogenic microorganisms. If that proves to be the case in vivo, such structures could have a role in preventing or reducing some infectious diseases.     

Costs of acid-related disorders to a health maintenance organization

BACKGROUND: Little is known about the economic impact of the acid-related disorders (ARDs), which include dyspepsia, gastritis, gastroesophageal reflux disease (GERD), and peptic ulcer disease (PUD), in managed care patient populations. OBJECTIVES: To describe the prevalence of medically attended ARDs, and their direct medical costs from the perspective of a large health maintenance organization (HMO). METHODS: A total of 1,550 ARDs subjects (age > or = 18 years), were randomly sampled from outpatient diagnosis and pharmacy databases of the Kaiser Permanente Medical Care Program of Northern California and verified by chart review. Five age- and gender-matched controls were identified per subject. One-year prevalence, excess annual costs, and initial 6-month costs for incident cases were estimated using the HMO cost accounting system. RESULTS: Total ARDs prevalence (5.8%) increases with advancing age. GERD is the most common ARD (2.9% overall prevalence). Annual per person attributable costs were $1,183, $471, and $431 respectively for PUD, GERD, and gastritis/dyspepsia. Excess inpatient costs for PUD explain its higher costs. Outpatient costs were somewhat higher for GERD ($279) than for PUD or gastritis/dyspepsia. Pharmacy costs were relatively low for each condition, in part because many patients were treated with generic cimetidine. Total annual HMO expenditures for ARDs were $59.4 million, with 40.6%, 36.8%, and 22.6% respectively for GERD, PUD, and gastritis/dyspepsia. CONCLUSIONS: Acid-related disorders, particularly GERD and PUD, contribute substantially to the direct costs of medical care in this managed care population.     

Enzymic assay for uric acid in milk

Summary The adaptation of a commerically available enzymatic test kit to the determination of uric acid in milk is described. The basis for the assay is the enzymatic conversion of a) uric acid to allantoin and hydrogen peroxide (uricase), b) reaction of the peroxide with ethanol (catalase), c) reduction of the acetaldehyde formed to ethanol (alcohol dehydrogenase) and measurement of the disappearance of NADH, which is proportional to the uric acid concentration in the sample. The method proved to be highly accurate (recovery of added uric acid =99%), rapid an precise (CV=3.57%).

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Enzymatische Bestimmung von Harnsäure in Milch

Zusammenfassung Es wird die Anpassung eines käuflichen Testes für die enzymatische Bestimmung von Harnsäure an Milch als Substrat beschrieben. Die Bestimmung basiert auf der enzymatischen Umwandlung von Harnsäure in Allantoin und Wasserstoffperoxid mit Uricase, dem Umsatz des Peroxides mit Katalase und Ethanol, der Reduktion des gebildeten Acetaldehydes mit NADH und Alkoholdehydrogenase. Der Verbrauch an NADH ist proportional dem Harnsäuregehalt der Milch. Die Methode ist sehr genau (99% Wiederfindungsrate bei zugesetzter Harnsäure), schnell und präzise (VK=3,57%).