JCell : a Java framework for inferring genetic networks

JCell is a framework for reconstructing and simulating genetic networks in the field of molecular biology. It is completely implemented in Java. The main goal of JCell is to gain deep insights of molecular processes within a cell or tissue under various conditions such as drug concentrations or pathogenic mutations. This question has recently become a major area of research in the field of bioinformatics, because understanding the regulating dependencies enables new therapies of diseases like cancer or Alzheimer. To address the mentioned inference problem, several mathematical models and algorithms have been developed and implemented, which try to infer genetic relationships from genomic experiment data. The program consists of a modular structure, which enables users to utilize the framework also in other research areas such as metabolic pathway reconstruction, signalling cascade analysis or general biochemical processes. Further on, JCell can also be used in other contexts to identify dynamic systems from time series data such as financial applications or engineering problems. Usability was always the primary focus during development, so that even users without a strong computer science background are able to use the program. Another focus was the ability of JCell to natively import as much file formats as possible to be compatible with the most commonly used analysis tools. Due to the usage of the programming language Java, the framework is platform independent and thus able to work on most hardware/software systems. This is especially important for those research facilities where no expensive hardware can purchased and where no restrictions for the used operating systems can be implied. Further more, the framework is open to public development and new modules can be easily implemented.JCell ist ein komplett in Java realisiertes Framework zur Rekonstruktion und Simulation von genetischen Netzwerken in verschiedenen Bereichen der Molekularbiologie. Ziel ist die eingehende Untersuchung von Abläufen innerhalb einer Zelle oder eines Gewebetyps bei gleichzeitiger Zugabe von Wirkstoffen oder im Falle von krankhafter Entartung. Diese Fragestellung ist zur Zeit eines der wichtigsten Themengebiete der Bioinformatik, da das Verständnis von genetischer Regulation tiefgreifende Möglichkeiten der Diagnostik und Therapie von Krankheiten wie Krebs oder Alzheimer eröffnet. Zur Lösung des so genannten Netzwerk-Inferenzproblems wurden verschiedene Algorithmen und mathematische Modelle implementiert, die aus gegebenen genomischen Experimentdaten versuchen, regulatorische Interaktionen zu rekonstruieren. Da die gewählte Programmstruktur modular aufgebaut ist, wurden im Laufe der Entwicklung weitere Einsatzgebiete erschlossen. So kann JCell nun auch in anderen Gebieten der Systembiologie, wie zum Beispiel der Forschung im Bereich metabolischer Systeme und der Rekonstruktion von biochemischen Signalwegen innerhalb einer Zelle, eingesetzt werden. Des Weiteren liegen Anfragen von Biotech-Firmen vor, die dynamische Prozesse in biotechnologischen Anlagen besser verstehen wollen. Bei der Entwicklung war stets die einfache Benutzbarkeit der Applikation das primäre Ziel, damit auch Computer-Laien in der Lage sind, das Programm zu bedienen. Ein weiteres Augenmerk lag auf der Implementierung von Methoden zum Einlesen verschiedenster Dateiformate, sodass die gängigsten Analysetools für Genomexperimente unterstützt werden. Durch Verwendung der Programmiersprache Java ist eine weitreichende Plattformunabhängigkeit gewährleistet, sodass JCell auf den meisten Rechnerarchitekturen läuft. Dies hat den Vorteil, dass Anwender keine spezielle Hardware bereitstellen müssen und auch keinerlei Einschränkungen bei der Auswahl eines Betriebssystems haben. Daneben bietet Java noch den Vorteil, dass fremde Entwickler schnell eigene Module in das bestehende Framework einbinden können, was besonders im Hinblick auf die Open-Source-Verfügbarkeit eine wichtige Rolle spielt

Business Model Innovation Through the Lens of Time: An Empirical Study of Performance Implications Across Venture Life Cycles

Current literature suggests that the innovation of a business model is among the most important success factors for organizations and has a positive influence on their performance. What is not yet clear, however, is how this relationship unfolds during an organization’s life cycle. We posit that business model innovation strongly contributes to firm performance in earlier phases, but ultimately gets less important. We therefore collected data on 250 organizations in Germany and used structural equation modeling for analytical purposes. We make the following two main contributions to the literature: (1) We confirm recent findings about the positive impact of business model innovation on performance; (2) we provide first empirical evidence for the important role of life cycle stages as moderator with regard to this relationship. With respect to the latter, our findings show that business model innovation is an important pathway of organizations, especially in their early years of existence, yet somewhat diminishing over time. In conclusion, this study opens new research avenues by extending and incorporating explanations for the life cycle theory and business model innovation

Regional lung aeration and ventilation during pressure support and biphasic positive airway pressure ventilation in experimental lung injury

INTRODUCTION: There is an increasing interest in biphasic positive airway pressure with spontaneous breathing (BIPAP+SBmean), which is a combination of time-cycled controlled breaths at two levels of continuous positive airway pressure (BIPAP+SBcontrolled) and non-assisted spontaneous breathing (BIPAP+SBspont), in the early phase of acute lung injury (ALI). However, pressure support ventilation (PSV) remains the most commonly used mode of assisted ventilation. To date, the effects of BIPAP+SBmean and PSV on regional lung aeration and ventilation during ALI are only poorly defined. METHODS: In 10 anesthetized juvenile pigs, ALI was induced by surfactant depletion. BIPAP+SBmean and PSV were performed in a random sequence (1 h each) at comparable mean airway pressures and minute volumes. Gas exchange, hemodynamics, and inspiratory effort were determined and dynamic computed tomography scans obtained. Aeration and ventilation were calculated in four zones along the ventral-dorsal axis at lung apex, hilum and base. RESULTS: Compared to PSV, BIPAP+SBmean resulted in: 1) lower mean tidal volume, comparable oxygenation and hemodynamics, and increased PaCO2 and inspiratory effort; 2) less nonaerated areas at end-expiration; 3) decreased tidal hyperaeration and re-aeration; 4) similar distributions of ventilation. During BIPAP+SBmean: i) BIPAP+SBspont had lower tidal volumes and higher rates than BIPAP+SBcontrolled; ii) BIPAP+SBspont and BIPAP+SBcontrolled had similar distributions of ventilation and aeration; iii) BIPAP+SBcontrolled resulted in increased tidal re-aeration and hyperareation, compared to PSV. BIPAP+SBspont showed an opposite pattern. CONCLUSIONS: In this model of ALI, the reduction of tidal re-aeration and hyperaeration during BIPAP+SBmean compared to PSV is not due to decreased nonaerated areas at end-expiration or different distribution of ventilation, but to lower tidal volumes during BIPAP+SBspont. The ratio between spontaneous to controlled breaths seems to play a pivotal role in reducing tidal re-aeration and hyperaeration during BIPAP+SBmean

TBC-2 Is Required for Embryonic Yolk Protein Storage and Larval Survival during L1 Diapause in Caenorhabditis elegans

C. elegans first stage (L1) larvae hatched in the absence of food, arrest development and enter an L1 diapause, whereby they can survive starvation for several weeks. The physiological and metabolic requirements for survival during L1 diapause are poorly understood. However, yolk, a cholesterol binding/transport protein, has been suggested to serve as an energy source. Here, we demonstrate that C. elegans TBC-2, a RAB-5 GTPase Activating Protein (GAP) involved in early-to-late endosome transition, is important for yolk protein storage during embryogenesis and for L1 survival during starvation. We found during embryogenesis, that a yolk::green fluorescent protein fusion (YP170::GFP), disappeared much more quickly in tbc-2 mutant embryos as compared with wild-type control embryos. The premature disappearance of YP170::GFP in tbc-2 mutants is likely due to premature degradation in the lysosomes as we found that YP170::GFP showed increased colocalization with Lysotracker Red, a marker for acidic compartments. Furthermore, YP170::GFP disappearance in tbc-2 mutants required RAB-7, a regulator of endosome to lysosome trafficking. Although tbc-2 is not essential in fed animals, we discovered that tbc-2 mutant L1 larvae have strongly reduced survival when hatched in the absence of food. We show that tbc-2 mutant larvae are not defective in maintaining L1 diapause and that mutants defective in yolk uptake, rme-1 and rme-6, also had strongly reduced L1 survival when hatched in the absence of food. Our findings demonstrate that TBC-2 is required for yolk protein storage during embryonic development and provide strong correlative data indicating that yolk constitutes an important energy source for larval survival during L1 diapause

Sex difference and intra-operative tidal volume: Insights from the LAS VEGAS study

BACKGROUND: One key element of lung-protective ventilation is the use of a low tidal volume (VT). A sex difference in use of low tidal volume ventilation (LTVV) has been described in critically ill ICU patients.OBJECTIVES: The aim of this study was to determine whether a sex difference in use of LTVV also exists in operating room patients, and if present what factors drive this difference.DESIGN, PATIENTS AND SETTING: This is a posthoc analysis of LAS VEGAS, a 1-week worldwide observational study in adults requiring intra-operative ventilation during general anaesthesia for surgery in 146 hospitals in 29 countries.MAIN OUTCOME MEASURES: Women and men were compared with respect to use of LTVV, defined as VT of 8 ml kg-1 or less predicted bodyweight (PBW). A VT was deemed 'default' if the set VT was a round number. A mediation analysis assessed which factors may explain the sex difference in use of LTVV during intra-operative ventilation.RESULTS: This analysis includes 9864 patients, of whom 5425 (55%) were women. A default VT was often set, both in women and men; mode VT was 500 ml. Median [IQR] VT was higher in women than in men (8.6 [7.7 to 9.6] vs. 7.6 [6.8 to 8.4] ml kg-1 PBW, P < 0.001). Compared with men, women were twice as likely not to receive LTVV [68.8 vs. 36.0%; relative risk ratio 2.1 (95% CI 1.9 to 2.1), P < 0.001]. In the mediation analysis, patients' height and actual body weight (ABW) explained 81 and 18% of the sex difference in use of LTVV, respectively; it was not explained by the use of a default VT.CONCLUSION: In this worldwide cohort of patients receiving intra-operative ventilation during general anaesthesia for surgery, women received a higher VT than men during intra-operative ventilation. The risk for a female not to receive LTVV during surgery was double that of males. Height and ABW were the two mediators of the sex difference in use of LTVV.TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, NCT01601223

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead