Fermentation characteristics of Dekkera bruxellensis strains

The influence of pH, temperature and carbon source (glucose and maltose) on growth rate and ethanol yield of Dekkera bruxellensis was investigated using a full-factorial design. Growth rate and ethanol yield were lower on maltose than on glucose. In controlled oxygen-limited batch cultivations, the ethanol yield of the different combinations varied from 0.42 to 0.45 g (g glucose)⁻¹ and growth rates varied from 0.037 to 0.050 h⁻¹. The effect of temperature on growth rate and ethanol yield was negligible. It was not possible to model neither growth rate nor ethanol yield from the full-factorial design, as only marginal differences were observed in the conditions tested. When comparing three D. bruxellensis strains and two industrial isolates of Saccharomyces cerevisiae, S. cerevisiae grew five times faster, but the ethanol yields were 0–13% lower. The glycerol yields of S. cerevisiae strains were up to six-fold higher compared to D. bruxellensis, and the biomass yields reached only 72–84% of D. bruxellensis. Our results demonstrate that D. bruxellensis is robust to large changes in pH and temperature and may have a more energy-efficient metabolism under oxygen limitation than S. cerevisiae.     

Spatial,temporal and interindividual epigenetic variation of functionally important DNA methylation patterns

DNA methylation is an epigenetic modification that plays an important role in gene regulation. It can be influenced by stochastic events, environmental factors and developmental programs. However, little is known about the natural variation of gene-specific methylation patterns. In this study, we performed quantitative methylation analyses of six differentially methylated imprinted genes (H19, MEG3, LIT1, NESP55, PEG3 and SNRPN), one hypermethylated pluripotency gene (OCT4) and one hypomethylated tumor suppressor gene (APC) in chorionic villus, fetal and adult cortex, and adult blood samples. Both average methylation level and range of methylation variation depended on the gene locus, tissue type and/or developmental stage. We found considerable variability of functionally important methylation patterns among unrelated healthy individuals and a trend toward more similar methylation levels in monozygotic twins than in dizygotic twins. Imprinted genes showed relatively little methylation changes associated with aging in individuals who are >25 years. The relative differences in methylation among neighboring CpGs in the generally hypomethylated APC promoter may not only reflect stochastic fluctuations but also depend on the tissue type. Our results are consistent with the view that most methylation variation may arise after fertilization, leading to epigenetic mosaicism.     

A Simple Dynamic Model of Respiratory Pump

To study the interaction of forces that produce chest wall motion, we propose a model based on the lever system of Hillman and Finucane (J Appl Physiol 63(3):951–961, 1987) and introduce some dynamic properties of the respiratory system. The passive elements (rib cage and abdomen) are considered as elastic compartments linked to the open air via a resistive tube, an image of airways. The respiratory muscles (active) force is applied to both compartments. Parameters of the model are identified in using experimental data of airflow signal measured by pneumotachography and rib cage and abdomen signals measured by respiratory inductive plethysmography on eleven healthy volunteers in five conditions: at rest and with four level of added loads. A breath by breath analysis showed, whatever the individual and the condition are, that there are several breaths on which the airflow simulated by our model is well fitted to the airflow measured by pneumotachography as estimated by a determination coefficient R ² ≥ 0.70. This very simple model may well represent the behaviour of the chest wall and thus may be useful to interpret the relative motion of rib cage and abdomen during quiet breathing.     

A randomized, rater-blinded, crossover study comparing the clinical efficacy of Ritalin® LA (methylphenidate) treatment in children with attention-deficit hyperactivity disorder under different breakfast conditions over 2 weeks

Several extended-release methylphenidate medications are available for treatment of children with ADHD. Pharmacokinetic investigations suggest that the serum levels of methylphenidate are partially altered when the medication is taken without breakfast. Clinical data comparing different breakfast situations are missing. In this study, different breakfast compositions and their influence on treatment with Ritalin LA are investigated. A total of 150 patients were enrolled in a rater-blinded, randomized crossover trial that compared a minimal breakfast with a standard breakfast in patients under stable treatment with Ritalin LA. Ratings for clinical efficacy were carried out after 1 week by teachers and parents (FBB-ADHS), as well as physicians (CGI). Additionally, a math test was administered to the patients. Of the total patients, 144 finished the trial with a breakfast compliance of 93%. All of the clinical rating scales showed consistently no difference between the two breakfast conditions. Non-inferiority of minimal breakfast versus standard breakfast was shown to be statistically significant (FBB-AHDS(Teacher): 0.97 with minimal breakfast, 1.01 with standard breakfast, P < 0.0001). The clinical efficacy of Ritalin LA is not influenced by breakfast and works independently of food intake.     

<Emphasis Type="Italic">Glyphiteuthis rhinophora</Emphasis> n. sp., a trachyteuthidid (Coleoidea,Cephalopoda) from the Cenomanian (Late Cretaceous) of Mexico

A new vampyropod coleoid from the Cenomanian limestones of Coahuila (Mexico) is described. Glyphiteuthis rhinophora n. sp. is classified as a member of the Trachyteuthididae because of its general gladius morphology. Within the genus Glyphiteuthis, Gl. rhinophora n. sp. is unique by its nose-shaped extension of the anterior median field extremity. The ventral gladius surface reflects the dorsal surface and lacks evidence of a phragmocone, so affiliations with sepiids are unlikely. Gl. rhinophora n. sp. represents the first Cenomanian record of a vampyropod coleoid in the New World and the first evidence of the genus outside the Tethyan and Boreal realm. The paleoenvironment indicates a nektonic lifestyle for Gl. rhinophora n. sp.     

Die Jugendmause europ?ischer und afrikanischer Schwarzkehlchen (Saxicola torquata rubicula undaxillaris) sowie von F1-Hybriden

Summary In a constant 12 h, 50 min equatorial photoperiod postjuvenile moult started earlier and lasted shorter in European stonechats than in their African conspecifics. F₁-hybrids showed an intermediary time course of moult indicating that the differences found between these two subspecies are genetically determined.     

Der innere Kalender tropischer Vögel

Im Jahre 1954 veröffentlichte der amerikanische Ornithologe James Chapin unter dem Titel ?The calendar of the wideawake fair”? die Ergebnisse einer elfjährigen Untersuchung an der Ruß-Seeschwalbe (Sterna fuscata) auf der tropischen Atlantikinsel Ascension. Wie auf vielen anderen Inseln versammeln sich diese Seeschwalben auch auf Ascension in regelmäßigen Intervallen zum gemeinsamen Brüten. Die Besonderheit der Vögel auf Ascension besteht darin, daß der Abstand zwischen aufeinanderfolgenden Fortpflanzungszeiten nicht wie sonst üblich ein Jahr beträgt, sondern nur knapp zehn Monate. Die Vögel brüten also in jedem Jahr rund zwei Monate früher als im Vorjahr. Ähnliche Fortpflanzungsrhythmen mit Periodendauern zwischen acht und elf Monaten sind später auch für eine Reihe anderer tropischer Seevögel, so etwa für die Gabelschwanzmöve (Creagrus furcatus) auf den Galapagosinseln, nachgewiesen worden. Zehnmonatige Brutrhythmen kommen gelegentlich auch bei landlebenden tropischen Vögeln vor, etwa bei der auf Borneo beheimateten Rotflügeltimalie (Stachyris erythroptera), die wie die Ruß-Seeschwalbe im zehnmonatigen Rhythmus brütet und mausert, oder bei manchen Paaren des Fledermausaars (Machaerhamphus alcinus).     

Biological systems modeling and analysis: a biomolecular technique of the twenty-first century.

It is proposed that computational systems biology should be considered a biomolecular technique of the twenty-first century, because it complements experimental biology and bioinformatics in unique ways that will eventually lead to insights and a depth of understanding not achievable without systems approaches. This article begins with a summary of traditional and novel modeling techniques. In the second part, it proposes concept map modeling as a useful link between experimental biology and biological systems modeling and analysis. Concept map modeling requires the collaboration between biologist and modeler. The biologist designs a regulated connectivity diagram of processes comprising a biological system and also provides semi-quantitative information on stimuli and measured or expected responses of the system. The modeler converts this information through methods of forward and inverse modeling into a mathematical construct that can be used for simulations and to generate and test new hypotheses. The biologist and the modeler collaboratively interpret the results and devise improved concept maps. The third part of the article describes software, BST-Box, supporting the various modeling activities.     

Modern bivalve shell assemblages on three atolls offshore Belize (Central America,Caribbean Sea)

The Belize atolls—Glovers Reef, Lighthouse Reef and Turneffe Islands—show differences in geomorphology, lagoonal depth, bottom sediment, growth of mangroves and sea-grass, exposure to waves and currents as well as in their sedimentation rates and their age. Bivalve shell assemblages in lagoonal areas reflect these geomorphological differences. On each atoll, 32 to 44 recent sediment samples were taken (total number of samples 111) and bivalve shells subsequently identified. The resulting database (32,122 bivalve shells in total) was analysed using Q-mode cluster analyses. Both the distribution of species characteristic of different lagoonal habitats and the distribution of bivalves with different life and feeding habits were investigated. Epifaunal suspension feeders were found particularly on hard-bottom along the reef-crests or clinging to mangrove roots. Infaunal suspension feeders show a more diverse distribution. Deeper lagoonal parts and areas with mangrove growth are often inhabited by chemosymbiont-carrying bivalves, indicating locations of reduced sediment. Deep burrowing detritus feeders are very abundant in shallow-water areas with moderate to high water agitation and were seldom found in Halimeda-rich sediments.