Alterations of tryptophan metabolism induced by sleep deprivation

Zusammenfassung Es wird gezeigt, dass Schlafentzug die Ausscheidung der 5-Hydroxyindolessigsäure und der Xanthurensäure vermehrt und diejenige der Antranilsäure herabsetzt.     

Shoot control of root development and nodulation is mediated by a receptor-like kinase

In legumes, root nodule organogenesis is activated in response to morphogenic lipochitin oligosaccharides that are synthesized by bacteria, commonly known as rhizobia. Successful symbiotic interaction results in the formation of highly specialized organs called root nodules, which provide a unique environment for symbiotic nitrogen fixation. In wild-type plants the number of nodules is regulated by a signalling mechanism integrating environmental and developmental cues to arrest most rhizobial infections within the susceptible zone of the root. Furthermore, a feedback mechanism controls the temporal and spatial susceptibility to infection of the root system. This mechanism is referred to as autoregulation of nodulation, as earlier nodulation events inhibit nodulation of younger root tissues. Lotus japonicus plants homozygous for a mutation in the hypernodulation aberrant root (har1) locus escape this regulation and form an excessive number of nodules. Here we report the molecular cloning and expression analysis of the HAR1 gene and the pea orthologue, Pisum sativum, SYM29. HAR1 encodes a putative serine/threonine receptor kinase, which is required for shoot-controlled regulation of root growth, nodule number, and for nitrate sensitivity of symbiotic development.     

Identifying distinct classes of bladder carcinoma using microarrays

Bladder cancer is a common malignant disease characterized by frequent recurrences. The stage of disease at diagnosis and the presence of surrounding carcinoma in situ are important in determining the disease course of an affected individual. Despite considerable effort, no accepted immunohistological or molecular markers have been identified to define clinically relevant subsets of bladder cancer. Here we report the identification of clinically relevant subclasses of bladder carcinoma using expression microarray analysis of 40 well characterized bladder tumors. Hierarchical cluster analysis identified three major stages, Ta, T1 and T2-4, with the Ta tumors further classified into subgroups. We built a 32-gene molecular classifier using a cross-validation approach that was able to classify benign and muscle-invasive tumors with close correlation to pathological staging in an independent test set of 68 tumors. The classifier provided new predictive information on disease progression in Ta tumors compared with conventional staging (P < 0.005). To delineate non-recurring Ta tumors from frequently recurring Ta tumors, we analyzed expression patterns in 31 tumors by applying a supervised learning classification methodology, which classified 75% of the samples correctly (P < 0.006). Furthermore, gene expression profiles characterizing each stage and subtype identified their biological properties, producing new potential targets for therapy.     

YidC mediates membrane protein insertion in bacteria

The basic machinery for the translocation of proteins into or across membranes is remarkably conserved from Escherichia coli to humans. In eukaryotes, proteins are inserted into the endoplasmic reticulum using the signal recognition particle (SRP) and the SRP receptor, as well as the integral membrane Sec61 trimeric complex (composed of alpha, beta and gamma subunits). In bacteria, most proteins are inserted by a related pathway that includes the SRP homologue Ffh, the SRP receptor FtsY, and the SecYEG trimeric complex, where Y and E are related to the Sec61 alpha and gamma subunits, respectively. Proteins in bacteria that exhibit no dependence on the Sec translocase were previously thought to insert into the membrane directly without the aid of a protein machinery. Here we show that membrane insertion of two Sec-independent proteins requires YidC. YidC is essential for E. coli viability and homologues are present in mitochondria and chloroplasts. Depletion of YidC also interferes with insertion of Sec-dependent membrane proteins, but it has only a minor effect on the export of secretory proteins. These results provide evidence for an additional component of the translocation machinery that is specialized for the integration of membrane proteins.     

宇宙学与战略"大思维"

宇宙学在近当代获得了长足发展,而这一发展正是孕育于强大而极富创造性的思维母体。从一般系统理论的角度来说,公司或政府机构等大型商业或政治组织的领导人可以利用宇宙学及其思维方法,进行战略性“大思维”,从而做出正确的决策。在本文中,作者不仅对宇宙学的具体理论和原则进行了归纳总结,而且还提出具体实例,以为这些领导人运用宇宙学进行战略高度的“大思维”提供佐证,从而进一步证明,“大思维”对于在复杂的现代组织中取得成功具有重要意义。     

Das statistische Problem der Gestalt fadenförmiger Moleküle

Ohne Zusammenfassung     

Data Mining as an Enabler for Customer Data Driven Vehicle Development

对于汽车等面向消费者的行业,数据驱动的产品开发是一项关键的系统工程。数据驱动方法的前提是数据本身,由于现代车辆的联网能力不断提高,使得汽车制造商能够以内部总线信号的形式记录并储存客户数据。由于这些数据并不用于外部,只用于内部通信以保证车辆的安全性和功能性,这给这些数据的应用带来了一定的困难,因此汽车行业的主要问题在于如何利用数据挖掘技术从这些数据中提取客户需求及相关信息。为此,对上述数据应用问题进行了文献调研,并在此基础上开展数据挖掘的模拟研究,以确定现有数据挖掘过程在需求获取领域的适用性;进而提出一种扩展程序,使得数据挖掘技术能够应用于相关客户数据之中,从而加快车辆开发的进程。