Entropy decay for the Kac evolution

We consider solutions to the Kac master equation for initial conditions where $N$ particles are in a thermal equilibrium and $M\le N$ particles are out of equilibrium. We show that such solutions have exponential decay in entropy relative to the thermal state. More precisely, the decay is exponential in time with an explicit rate that is essentially independent on the particle number. This is in marked contrast to previous results which show that the entropy production for arbitrary initial conditions is inversely proportional to the particle number. The proof relies on Nelson's hypercontractive estimate and the geometric form of the Brascamp-Lieb inequalities due to Franck Barthe. Similar results hold for the Kac-Boltzmann equation with uniform scattering cross sections.Comment: 26 page

Lösungsraumanalyse für Plug-In-Hybridfahrzeuge hinsichtlich Wirtschaftlichkeit und Bauraumkonzept

Ein verändertes Umfeld für individuelle Mobilität lässt neben Elektrofahrzeugen auch Plug-In-Hybridfahrzeuge (PHEVs) in den Fokus der Öffentlichkeit rücken. Für die Entwicklung solcher Fahrzeugkonzepte existiert ein technischer Lösungsraum, der sich in Maßkonzept, Topologie, Komponententyp und -auslegung gliedert. In einem strukturierten Vorgehen wird der große technische Lösungsraum mit geeigneten Prämissen eingegrenzt. Der Lösungsraum aus Energieinhalt des elektrochemischen Hochvolt-Speichers (HV-Speicher) und Leistung der elektrischen Maschine wird hinsichtlich Wirtschaftlichkeit und Bauraumkonzept analysiert. In der Wirtschaftlichkeitsanalyse von PHEVs aus Käufersicht werden die Mehrkosten in der Anschaffung den reduzierten Verbrauchskosten bei der Nutzung eines PHEVs im Vergleich zu einem rein verbrennungsmotorischen Fahrzeug gegenübergestellt. Die Reduzierung der Verbrauchskosten resultiert aus der Kraftstoffverbrauchseinsparung eines PHEVs, ermittelt mit dem neuen europäischen Fahrzyklus und mit monatelang aufgezeichneten Realfahrten verschiedener Fahrer. Die Wirtschaftlichkeitsanalyse zeigt, dass ein PHEV für Käufer ein attraktives Angebot darstellt, vor allem zukünftig sowie abhängig vom Fahr- und Nutzungsprofil. Außerdem wird der optimale Auslegungsbereich des elektrischen Systems eines PHEVs identifiziert. Für das Optimum darf der Energieinhalt des HV-Speichers nicht zu klein gewählt werden aufgrund eines hohen Grundbetrags an zusätzlichen Herstellkosten für Automobilhersteller, der im Rahmen von Mehrkosten an Käufer weitergegeben wird. HV-Speicher mit eher höherem Energieinhalt sind auch außerhalb des Optimums wegen der stärker steigenden Mehrkosten im Vergleich zum geringer zunehmenden Verbrauchsvorteil. Der Schwerpunkt der Bauraumkonzeptanalysen liegt auf der geometrischen Integration des HV-Speichers in das Gesamtfahrzeug. Dies stellt eine große Herausforderung dar aufgrund der geringen Energiedichte des HV-Speichers im Vergleich zu Benzin. Die Bauraumanalyse identifiziert bevorzugte Integrationsmöglichkeiten bei PHEVs im Tunnel- und Tankbereich sowie deren Kombination. Der in diesen Bauräumen mögliche Energieinhalt wird durch die HV-Speicheranalyse festgelegt. Der ermittelte optimale Auslegungsbereich im Lösungsraum des elektrischen Systems hinsichtlich der Wirtschaftlichkeit aus Käufersicht wird unter geometrischen Randbedingungen aus der Bauraumkonzeptanalyse weiter eingegrenzt. Der Kern des ganzheitlichen Ansatzes sind entwickelte parametrische Modelle für die Anwendung in der frühen Entwicklungsphase auf Komponenten- und Gesamtfahrzeugebene in MATLAB, MS Excel und CATIA V5. Neben den Ergebnissen für das Jahr 2011/12 zeigen Prognosen die Entwicklungen bis in die Jahre 2020 und 2025. Sensitivitätsanalysen zeigen die Auswirkungen von Variation der Parameter und Prämissen. Der interdisziplinäre Ansatz mit der erstmaligen Kombination von Kosten, Verbrauch und Bauraumkonzept eines PHEVs zur optimalen Auslegung des elektrischen Systems stellt den wissenschaftlichen Beitrag dar.Plug-in hybrid electric vehicles (PHEVs) are shifted into the focus of the general public alongside battery electric vehicles because of the changing environment for individual mobility. There is a wide technical solution scope for the vehicle concept characteristics that consists of main vehicle dimensions, drive train and energy storage architectures, component technology as well as dimensioning. In a systematic design approach, the technical solution scope for PHEVs is defined based on suitable assumptions and is then analysed for the energy capacity in the high-voltage accumulator (HV-accumulator) and the peak power output of the electrical motor. The analysis of the economic efficiency of PHEVs for customers contrasts the additional acquisition costs with the reduced costs for consumption of a PHEV in relation to a comparable internal combustion engine vehicle. The savings of the costs for consumption results from reduced fuel consumption. The basis of the analysis is the New European Driving Cycle and real-life driving profiles, measured over several months. The analysis of the economic efficiency shows that a PHEV is an attractive offer for customers, dependent on the driving and usage behaviour. Furthermore, an optimal dimensioning of the electrical system is identified for the HV-accumulator. A too small HV-accumulator is not beneficial due to a high basic amount of additional manufacturing costs for the car manufacturer, which is passed as additional acquisition costs to the customer. The same holds true for a HV-accumulator that is too large due to the relatively slow rise in benefits of fuel consumption compared with the increase in acquisition costs. In the geometrical analysis the installation of the HV-accumulator in the total vehicle is the major challenge because of the small energy density compared to fuel. The analysis of the constructed spaces in a vehicle identifies PHEVs preferred installation spaces for the HV-accumulator in the tunnel and tank area as well as the combination of both. The following analysis of the HV-accumulator estimates the possible energy content in the specific installation space. The identified optimal configuration range of the electrical system regarding economic efficiency of PHEVs for customers is additionally limited due to geometrical boundary conditions as a result of the geometrical analysis. The basis of the holistic approach are developed parametric models for the analysis in the early stage of vehicle development on component and total vehicle level in MATLAB, MS Excel and CATIA V5. Additionally to the results for 2011/12, forecasts for 2020 and 2025 are presented. Effects of varying assumptions and the characteristics of the electrical system are investigated via sensitivity analysis. The interdisciplinary approach combining costs, consumption and geometrical design for the first time and therefore determining an optimal dimensioning of the electrical system in PHEVs represents the scientific contribution

Arabidopsis Extra-Large G Proteins (XLGs) in phosphate homeostasis

Phosphorus, which is taken up as inorganic phosphate (Pi), is one of the most limiting nutrients for plants. To maintain Pi homeostasis, many proteins (e.g. SPX domain proteins) are involved in signalling pathways to mediate different plant responses. In addition to the canonical heterotrimeric G proteins, the Arabidopsis genome encodes three Gα-like proteins, named Extra-Large G proteins: XLG1, XLG2, and XLG3. This project study the role of XLGs in Pi homeostasis in Arabidopsis thaliana. Analysis of the shoot Pi content showed a decreased accumulation in xlg1-2 and xlg3-2 single mutants, which is more notable in the xlg1-2 xlg3-2 double mutant. Under Pi starvation, the xlg1-2 xlg3-2 double mutant developed longer primary roots compared to wild-type plants, while the single xlg mutants were not significant different. Furthermore, all tested xlg single and double mutants showed a tendency toward increased transcript levels of phosphate starvation induced genes compared to the wild-type. Additionally, yeast two-hybrid assays showed an interaction between SPX proteins and XLG1 and XLG3. AtSPX1, a phosphate-dependent inhibitor of the MYB-type transcription factor Phosphate Starvation Response 1 (PHR1), interacts with both AtXLG1 and AtXLG3. However, AtSPX-MFS1, a vacuolar transporter that mediates phosphate storage, only interacts with AtXLG3. These results suggest that XLGs proteins may play a role in Pi homeostasis together with SPX proteins. To test for brassinosteroid related phenotypes, plants were treated with the brassinosteroid biosynthesis inhibitor brassinazole (BRZ). The xlg3-2 mutant showed a decreased in hypocotyl length compared to wild-type, while the xlg1-2 and spx1-1 mutants did not. The xlg1-2 xlg3-2 double mutant showed the same tendency as the xlg3-2, suggesting that the phenotype is caused by the XLG3 mutation. Taken together, these results suggest that XLGs proteins may be involved in different signaling pathways. Nevertheless, little is known about these signalling proteins, and further studies are needed to define how they work

Mapping of Multiple DNA Gains and Losses in Primary Small Cell Lung Carcinomas by Comparative Genomic Hybridization

Comparative genomic hybridization was applied for a comprehensive screening of under- and overrepresentation of genetic material in 13 autoptic small cell lung cancer specimens. The most abundant genetic changes include DNA losses of chromosome arms 3p, 5q, 10q, 13q, and 17p and DNA gains of 3q, 5p, 8q, and 17q. Amplification sites in these tumors were mapped to 22 chromosome bands. The most frequently involved band was 19q13.1 (4 cases). Bands 1p32, 2p23, 7q11.2, 8q24, and 13q33–34 were involved in two cases each

Molecular cytogenetic analysis of formalin-fixed, paraffin-embedded solid tumors by comparative genomic hybridization after universal DNA-amplification

We present a technique which allows the detection and chromosomal localization of DNA sequence copy number changes in solid tumor genomes from frozen sections and paraffin embedded, formalin fixed specimens. Based on comparative genomic hybridization and on universal DNA amplification procedures this technique is possible even if only a few tumor cells are available. We demonstrate the feasibility of this method to visualize complete and partial chromosome gains and losses and gene amplifications In archived solid tumor samples

Evaluating annotations of an Agilent expression chip suggests that many features cannot be interpreted

<p>Abstract</p> <p>Background</p> <p>While attempting to reanalyze published data from Agilent 4 × 44 human expression chips, we found that some of the 60-mer olignucleotide features could not be interpreted as representing single human genes. For example, some of the oligonucleotides align with the transcripts of more than one gene. We decided to check the annotations for all autosomes and the X chromosome systematically using bioinformatics methods.</p> <p>Results</p> <p>Out of 42683 reporters, we found that 25505 (60%) passed all our tests and are considered "fully valid". 9964 (23%) reporters did not have a meaningful identifier, mapped to the wrong chromosome, or did not pass basic alignment tests preventing us from correlating the expression values of these reporters with a unique annotated human gene. The remaining 7214 (17%) reporters could be associated with either a unique gene or a unique intergenic location, but could not be mapped to a transcript in RefSeq. The 7214 reporters are further partitioned into three different levels of validity.</p> <p>Conclusion</p> <p>Expression array studies should evaluate the annotations of reporters and remove those reporters that have suspect annotations. This evaluation can be done systematically and semi-automatically, but one must recognize that data sources are frequently updated leading to slightly changing validation results over time.</p

Acute kidney injury in septua- and octogenarians after cardiac surgery

Background An increasing number of septua- and octogenarians undergo cardiac surgery. Acute kidney injury (AKI) still is a frequent complication after surgery. We examined the incidence of AKI and its impact on 30-day mortality. Methods A retrospective study between 01/2006 and 08/2009 with 299 octogenarians, who were matched for gender and surgical procedure to 299 septuagenarians at a university hospital. Primary endpoint was AKI after surgery as proposed by the RIFLE definition (Risk, Injury, Failure, Loss, End-stage kidney disease). Secondary endpoint was 30-day mortality. Perioperative mortality was predicted with the logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE). Results Octogenarians significantly had a mean higher logistic EuroSCORE compared to septuagenarians (13.2% versus 8.5%; p < 0.001) and a higher proportion of patients with an estimated glomerular filtration rate (eGFR) < 60 ml × min-1 × 1.73 m-2. In contrast, septuagenarians showed a slightly higher median body mass index (28 kg × m-2 versus 26 kg × m-2) and were more frequently active smoker at time of surgery (6.4% versus 1.6%, p < 0.001). Acute kidney injury and failure developed in 21.7% of septuagenarians and in 21.4% of octogenarians, whereas more than 30% of patients were at risk for AKI (30% and 36.3%, respectively). Greater degrees of AKI were associated with a stepwise increase in risk for death, renal replacement therapy and prolonged stays at the intensive care unit and at the hospital in both age groups, but without differences between them. Overall 30-day mortality was 6% in septuagenarians and 7.7% in octogenarians (p = 0.52). The RIFLE classification provided accurate risk assessment for 30-day mortality and fair discriminatory power. Conclusions The RIFLE criteria allow identifying patients with AKI after cardiac surgery. The high incidence of AKI in septua- and octogenarians after cardiac surgery should prompt the use of RIFLE criteria to identify patients at risk and should stimulate institutional measures that target AKI as a quality improvement initiative for patients at advanced age

Reduced 30-day mortality in men after elective coronary artery bypass surgery with minimized extracorporeal circulation-a propensity score analysis

Background Impact of minimized extracorporeal circulation (MECC) for coronary surgery on mortality remains controversial and gender significantly influence outcome. Methods We analyzed 3,139 male patients undergoing elective coronary surgery between 01/2004 and 05/2009. Using propensity score matching after binary logistic regression, 1,005 patients (from 1,119 patients) undergoing surgery with MECC could be matched with 1,005 patients (from 2,020 patients) undergoing surgery with conventional extracorporeal circulation (CECC). Primary outcome was 30-day mortality. Results Unadjusted 30-day mortality was 2.7% in patients with CECC and 0.8% in those with MECC (mean difference -1.9%; p < 0.001). The adjusted mean difference (average treatment effect of the treated) after matching was -1.5% (95% confidence interval (CI) -2.6 to -0.4; p = 0.006). Postoperative hospital stay was shorter in patients operated with minimized systems (adjusted mean difference -0.8 days; 95% CI -1.46 to -0.09; p = 0.03) and incidence of postoperative neurocognitive dysfunction was also lower (adjusted mean difference -1.3%; 95% CI -2.2 to -0.4; p = 0.001). Chest tube drainage (adjusted mean difference +22 mL; 95% CI -47 to 91; p = 0.5) and risk for acute kidney injury, kidney injury and failure according to RIFLE criteria (adjusted mean difference -1.0%; 95% CI -2.5 to 0.6; p = 0.24) proved to be insignificant between both groups. Apart from reduced 30-day mortality, however, average treatment effects for intensive care unit stay, postoperative hospital stay, chest tube drainage and kidney injury did not significantly differ. Conclusion Using propensity score analysis, we observed an association between MECC and reduced 30-day mortality in men, but our results call for further analysis

A strategy for the characterization of minute chromosome rearrangements using multiple color fluorescence in situ hybridization with chromosome-specific DNA libraries and YAC clones

The identification of marker chromosomes in clinical and tumor cytogenetics by chromosome banding analysis can create problems. In this study, we present a strategy to define minute chromosomal rearrangements by multicolor fluorescence in situ hybridization (FISH) with whole chromosome painting probes derived from chromosome-specific DNA libraries and Alu-polymerase chain reaction (PCR) products of various region-specific yeast artificial chromosome (YAC) clones. To demonstrate the usefulness of this strategy for the characterization of chromosome rearrangements unidentifiable by banding techniques, an 8p+ marker chromosome with two extra bands present in the karyotype of a child with multiple anomalies, malformations, and severe mental retardation was investigated. A series of seven-color FISH experiments with sets of fluorochrome-labeled DNA library probes from flow-sorted chromosomes demonstrated that the additional segment on 8p+ was derived from chromosome 6. For a more detailed characterization of the marker chromosome, three-color FISH experiments with library probes specific to chromosomes 6 and 8 were performed in combination with newly established telomeric and subtelomeric YAC clones from 6q25, 6p23, and 8p23. These experiments demonstrated a trisomy 6pter6p22 and a monosomy 8pter8p23 in the patient. The present limitations for a broad application of this strategy and its possible improvements are discusse