Microbiological oxidation of 2-methylbutanol of differing enantiomeric ratios by Gluconobacter species

 2-Methylbutanoic acid, an aroma compound of high economic interest, was synthesised using Gluconobacter species for bioconversion. The main focus was on enantioselective effects during metabolism. A preference for the (S)-enantiomer was observed when the microorganisms were fed with 2-methylbutanol of known enantiomeric ratios. Received: 15 December 1997     

Dynamic Aspects of Stimulus-Response Correspondence: Evidence for Two Mechanisms Involved in the Simon Effect.

It has been recently proposed that the time course of the Simon effect may vary across tasks, which might reflect different types of stimulus-response (S-R) transmissions (E. Wascher, U. Schatz, T. Kuder, & R. Verleger, 2001). The authors tested this notion in 4 experiments by comparing Simon effects evoked by horizontal and vertical S-R arrangements. The temporal properties of the effect, as well as lateralized readiness potential-difference waves, indicated a fast and transient influence of the horizontal, but a slow and sustained influence of the vertical spatial stimulus feature on performance. Additional evidence for this temporal dissociation was obtained in experiments that induced a shortening or lengthening of the mean response time. Thus, the data strongly indicate that there are 2 temporally dissociable mechanisms involved in generating the Simon effect for horizontal and vertical S-R relations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender Recognition From Point-Light Walkers.

Point-light displays of human gait provide information sufficient to recognize the gender of a walker and are taken as evidence of the exquisite tuning of the visual system to biological motion. The authors revisit this topic with the goals of quantifying human efficiency at gender recognition. To achieve this, the authors first derive an ideal observer for gender recognition on the basis of center of moment (J. E. Cutting, D. R. Proffitt, & L. T. Kozlowski, 1978) and, with the use of anthropometric data from various populations, show optimal recognition of ～79% correct. Next, they perform a meta-analysis of 21 experiments examining gender recognition, obtaining accuracies of 66% correct for a side view and 71% for other views. Finally, results of the meta-analysis and the ideal observer are combined to obtain estimates of human efficiency at gender recognition of 26% for the side view and 47% for other views. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Osteoclast Differentiation Is Impaired in a Subgroup of SLE Patients and Correlates Inversely with Mycophenolate Mofetil Treatment

Osteoporosis can arise in systemic lupus erythematosus (SLE) patients secondary to medication and/or chronic inflammation. To analyze if patients with SLE have phenotypically-impaired osteoclastogenesis, we differentiated ex vivo monocytes from 72 SLE patients and 15 healthy individuals into osteoclasts followed by TRAP staining and counting. We identified a subgroup of SLE patients (45%) with a significantly impaired osteoclast differentiation, relative to the other SLE patients or healthy individuals (OR 11.2; 95% CI 1.4–89.9). A review of medication indicated that patients with osteoclast counts equal to healthy donors were significantly more likely to be treated with mycophenolate mofetil (MMF) compared to patients with impaired osteoclastogenesis. We analyzed expression of RANKL and the MMF target genes IMPDH1 and IMPDH2 in osteoclasts by qPCR, but detected no difference. Since MMF might influence interferon-α (IFNα) and -γ (IFNγ) we measured serum IFNα and IFNγ levels. Patients with very low osteoclast counts also had comparably higher IFNα serum levels than patients with normal osteoclast counts. We conclude that in vitro osteoclastogenesis is impaired in a subgroup of SLE patients. This correlates inversely with MMF treatment and high IFNα serum levels. Further observational study will be required to determine whether this translates into a clinically meaningful effect.     

Occurrence and role of algae and fungi in acid mine drainage environment with special reference to metals and sulfate immobilization

Passive remediation of Acid Mine Drainage (AMD) is a popular technology under development in current research. Roles of algae and fungi, the natural residents of AMD and its attenuator are not emphasized adequately in the mine water research. Living symbiotically various species of algae and fungi effectively enrich the carbon sources that help to maintain the sulfate reducing bacterial (SRB) population in predominantly anaerobic environment. Algae produce anoxic zone for SRB action and help in biogenic alkalinity generation. While studies on algal population and actions are relatively available those on fungal population are limited. Fungi show capacity to absorb significant amount of metals in their cell wall, or by extracellular polysaccharide slime. This review tries to throw light on the roles of these two types of microorganisms and to document their activities in holistic form in the mine water environment. This work, inter alia, points out the potential and gap areas of likely future research before potential applications based on fungi and algae initiated AMD remediation can be made on sound understanding.     

Miniaturization of an Enzyme Assay (β-Galactosidase) in the 384- and 1536-Well Plate Format

Miniaturization is one way to realize today's demands in the drug discovery process by moving from the standard 96-well plate to higher density microplate formats. In this article we describe the adaptation of a fluorescence-based enzyme assay to the challenges of the 384- and 1536-well plate format. The liquid-handling was realized by the automated micropipettor CyBi-Well™ 96/384/1536* (CyBio AG - formerly JENOPTIK Bioinstruments Gmbh - Jena, Germany). On the basis of optimized liquid-handling parameters pipetting routines were established to perform an enzyme assay (β-galactosidase) in the microplate formats of higher density. Finally, the experimental results were compared to those obtained in the well-established 96-well format.

In the enzyme assay, the bioconversion of the substrate Fluorescein-di-(β-D-galactopyranoside) (FDG), occurred as a linear function of the β-galactosidase concentration comparably in all three assay formats. We conclude that miniaturization using the higher density 384- and 1536-well plate formats is advantageous as the next evolutionary step in HTS, especially using enzyme assays. A careful individual adaptation procedure for each microplate format and assay at the basis of the optimized liquid-handling parameters is essential. CyBi-Well™ 96/384/1536 proves to be a powerful tool for a careful adaptation of the liquid-handling procedures of biological assays especially also in the 384- and 1536-well formats.