Modification of the water oxidizing complex in leaves of the dgd1 mutant of Arabidopsis thaliana deficient in the galactolipid digalactosyldiacylglycerol

The primary biochemical defect in the genetically well characterized dgd1 mutant of Arabidopsis thaliana causes a 90% reduction in the relative amount of the galactolipid digalactosyldiacylglycerol (DGDG). To study the effect of this DGDG deficiency on photosystem II (PS II), time-resolved transients of laser-flash-induced changes of the relative fluorescence quantum yield Fvar,rel(t) were measured in whole leaves from wild-type and the dgd1 mutant. The results obtained reveal (i) in untreated leaves the decay kinetics of Fvar, rel(t) reflecting QA.- reoxidation by endogenous plastoquinone are very similar in wild-type and the dgd1 mutant at room temperature, (ii) the Arrhenius plot of the temperature dependence of electron transfer from QA.- to QB exhibits a break point at about 19 degrees C in wild-type and about 12 degrees C in the dgd1 mutant, (iii) in leaves treated with DCMU the slow reoxidation of QA.- by the PS II donor side is blocked to a much higher extent in the dgd1 mutant (about 50%) compared to wild-type (about 10%), and iv) the normalized amplitude of Fvar,rel(t = 1 micros) reflecting the percentage of fast P680.+ reduction by YZ exhibits a characteristic period four oscillation in wild-type while this feature is strongly damped in the dgd1 mutant. Presumably, the severe DGDG deficiency is causing the thermal down shift of a lipid phase transition that affects the QA.- reoxidation by QB. Most strikingly, the properties of the WOC are modified as a result of reduced DGDG content. Thus, the lipid DGDG appears to be of structural relevance for the WOC.     

Clinical experience of trabeculotomy for the surgical treatment of aniridic glaucoma

OBJECTIVE: The purpose of this study is to determine the efficacy of initial trabeculotomy in the patient with aniridic glaucoma. DESIGN: Clinical charts were reviewed. PARTICIPANTS: Twenty-nine eyes of 16 patients with aniridia were studied. INTERVENTION: Glaucoma surgery was performed. As an initial procedure, trabeculotomy was performed in 12 eyes, other surgery was performed in 17 eyes (trabeculectomy, 5; goniotomy, 5; other, 7). MAIN OUTCOME MEASURES: Success was defined as an intraocular pressure (IOP) of 21 mmHg or lower, and no further surgery was performed. RESULTS: Ten (83%) of 12 eyes obtained IOP control after first (6 eyes) or second (4 eyes) trabeculotomy with a mean follow-up period of 9.5 years. Five eyes maintained visual acuity of 20/40 to 20/200. No serious complications were found after trabeculotomy. Three (18%) of 17 eyes were controlled with the first glaucoma surgery other than trabeculotomy (goniotomy, trabeculectomy, trabeculectomy combined with trabeculotomy, and Molteno implant). Good IOP control was obtained in 8 (47%) of 17 eyes after several surgeries with a mean follow-up period of 10.4 years. Four of 17 eyes became phthisical. CONCLUSION: This study suggests that trabeculotomy is the preferred initial operation for uncontrolled glaucoma with aniridia.     

Autonomic function in a cohort of children with diabetes

129 diabetic children in Avon County participated in a longitudinal study of the evolution of microvascular disease together with 129 age- and sex-matched controls. Diabetic children had mean (+/- SD) age 12.7 (+/- 3.4) years (range: 3.7-16.8), mean (+/- SD) diabetes duration 3.9 (+/- 3.2) years (range: 0.1-13.4) and mean (+/- SD) HbA1 11.1% (+/- 2.2) (range: 6.5-18.2). Cardiovascular autonomic function was studied by four heart rate (HR) tests using a computerized system of HR monitoring. As a group, diabetic children had higher mean HR (p = 0.0004) and reduced max/min HR ratio while standing (p = 0.001), compared with the control children. HR ratio while standing was the only variable related to diabetes duration (r = -0.20, p = 0.018), while no correlation of HR variables with glycaemic control was found. Twenty diabetic children (15.5%) had one abnormal HR test. Ten diabetic children (7.7%) demonstrated abnormality in two or more HR tests. When compared with the other diabetic children in the cohort, these ten children were found to be younger in age (mean age: 9.4 vs 12.0 yr, p = 0.05), but did not otherwise differ in terms of diabetes duration or glycaemic control. No pubertal or sex effect in the development of diabetic autonomic neuropathy was detected. These findings suggest that autonomic function may be impaired early in childhood diabetes, independent of the duration of the disease or the quality of glycaemic control.     

MMPI and Rorschach: Three decades of research.

Research references on the Rorschach and the Minnesota Multiphasic Personality Inventory (MMPI) were counted for each year, 1950–1985, to analyze the trends noted by W. M. Reynolds and N. D. Sundberg (see record 1979-00119-001) and to test their prediction that research on personality tests would decline after 1971. Results show that there was a decline between 1971 and 1975. However, the number of Rorschach references leveled off after 1975, and there was a resurgence of interest in MMPI research. Recent data suggest that both tests continue to be popular topics for published research. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Perspectives on the use of the baboon in embryology and teratology research

This paper summarizes the developmental stages of the baboon during the period of organ formation and provides comparative information for other primates, including the human. Special attention is directed to the early development of the nervous system, eye, ear and nose/palate. The similarity in development of these structures with humans indicates that the baboon is a suitable model for studies of normal and abnormal neurological development. Spontaneous prenatal loss rates in the baboon (2.4-11.2%) are slightly lower than those reported in rhesus and cynomologus monkeys. The baboon, in addition to the cynomologus monkey and macaque, has been used as a model in teratology research to assess the potential risk of thalidomide, sex steroids, Bendectin and rubella virus, as well as to study the pathogenesis of malformations associated with the corticosteroid triamcinolone acetonide. The rate of spontaneous malformations (<1%) in baboons, similar to that reported for other commonly used primates, supports their continued use as a teratological model. In this regard, a sample protocol is provided for the safety evaluation of biotechnology products using nonhuman primates, which are the most appropriate model for those compounds which are bioactive in species closely related to humans.     

Usability of product X-lessons from a real product

Using the example of a real product, this paper shows how various usability assessments, conducted by different human factors engineers, in several phases of the product's development life-cycle, identified similar potential usability problems. Circumstances dictated that no remedial action was taken, so it was possible to track these potential usability defects to customer sites, where it was found that most of the important problems did indeed occur. Thus, it can be demonstrated that human factors advice was valid and reliable. In simpler terms, early usability evaluation by human factors engineers can save hours of wasted development effort and customer frustration, and can help to ensure that a more usable product is produced.     

Reversible Transformation and Elastic Anisotropy in Mg-ZrO2

Mechanical loading of polycrystalline ZrO₂ ceramics causes reversible, out-of-plane distortions at free surfaces that are parallel to the direction of applied stress. These distortions have been measured using optical interference microscopy, and the separate contributions due to elastic anisotropy and reversible mantensitic tranformation have been identified.     

Starter cultures employed in the manufacture of biofermented milks

The market for fermented milks is expanding as more consumers become interested in the possible health aspects of the product. This paper reviews the types of bacteria that are currently being used in the manufacture of biofermented milks. The requirements of a starter culture in terms of ability to ferment milk to a stable product and to provide the necessary sensory properties for consumer demands are outlined. The paper also discusses and highlights some of the problems encountered in developing milks for the health market using probiotic organisms such as Lactobacillus acidophilus and species of Bifidobacterium.