Analysis of Human TAAR8 and Murine Taar8b Mediated Signaling Pathways and Expression Profile

The thyroid hormone derivative 3-iodothyronamine (3-T₁AM) exerts metabolic effects in vivo that contradict known effects of thyroid hormones. 3-T₁AM acts as a trace amine-associated receptor 1 (TAAR1) agonist and activates G_s signaling in vitro. Interestingly, 3-T₁AM-meditated in vivo effects persist in Taar1 knockout-mice indicating that further targets of 3-T₁AM might exist. Here, we investigated another member of the TAAR family, the only scarcely studied mouse and human trace-amine-associated receptor 8 (Taar8b, TAAR8). By RT-qPCR and locked-nucleic-acid (LNA) in situ hybridization, Taar8b expression in different mouse tissues was analyzed. Functionally, we characterized TAAR8 and Taar8b with regard to cell surface expression and signaling via different G-protein-mediated pathways. Cell surface expression was verified by ELISA, and cAMP accumulation was quantified by AlphaScreen for detection of G_s and/or G_i/o signaling. Activation of G-proteins G_q/11 and G_12/13 was analyzed by reporter gene assays. Expression analyses revealed at most marginal Taar8b expression and no gender differences for almost all analyzed tissues. In heart, LNA-in situ hybridization demonstrated the absence of Taar8b expression. We could not identify 3-T₁AM as a ligand for TAAR8 and Taar8b, but both receptors were characterized by a basal G_i/o signaling activity, a so far unknown signaling pathway for TAARs.     

Predicting the Morphodynamic Response of Silt-Laden Rivers to Water and Sediment Release from Reservoirs: Lower Yellow River, China

The high sediment load of the Yellow River results in rapid infilling of its reservoirs when sediment is not regularly flushed. Simultaneously, the downstream reaches of the Yellow River experience extremely high siltation rates, which are reduced when sediment is retained in its reservoirs. To minimize siltation in the reservoirs and the downstream river bed, water and sediment are released from the reservoir in a controlled way through flushing experiments. In this paper, we analyze the effect of such a flushing event on the downstream river bed through data analysis and numerical modeling. Sedimentation may be minimized by relating the amount of sediment released from the reservoir to the sediment available for release through operational monitoring and by releasing relatively clear water after turbid water. Despite this flushing of sediment, the reservoir will eventually fill up, and more sediment released again into the lower Yellow River. The change in discharge magnitude and frequency brought about by the reservoir will then probably result in increased siltation rates in the lower Yellow River compared to the predam situation.     

Production of the tubulin destabilizer disorazol in Sorangium cellulosum: biosynthetic machinery and regulatory genes

Myxobacteria show a high potential for the production of natural compounds that exhibit a wide variety of antibiotic, antifungal, and cytotoxic activities. The genus Sorangium is of special biotechnological interest because it produces almost half of the secondary metabolites isolated from these microorganisms. We describe a transposon-mutagenesis approach to identifying the disorazol biosynthetic gene cluster in Sorangium cellulosum So ce12, a producer of multiple natural products. In addition to the highly effective disorazol-type tubulin destabilizers, S. cellulosum So ce12 produces sorangicins, potent eubacterial RNA polymerase inhibitors, bactericidal sorangiolides, and the antifungal chivosazoles. To obtain a transposon library of sufficient size suitable for the identification of the presumed biosynthetic gene clusters, an efficient transformation method was developed. We present here the first electroporation protocol for a strain of the genus Sorangium. The transposon library was screened for disorazol-negative mutants. This approach led to the identification of the corresponding trans-acyltransferase core biosynthetic gene cluster together with a region in the chromosome that is likely to be involved in disorazol biosynthesis. A third region in the genome harbors another gene that is presumed to be involved in the regulation of disorazol production. A detailed analysis of the biosynthetic and regulatory genes is presented in this paper.     

A multidimensional laser simulator for edge-emitters includingquantum carrier capture

A multidimensional semiconductor laser simulator is presented which follows a rate equation approach for the coupling between optics and electronics. Capture and emission rates for the bound and free carriers are used for the quantum well. The electronic equations and the optical equations are solved in a self-consistent manner for one, two, and three dimensions. As an example, an InGaAs quantum-well ridge laser is analyzed, and the multidimensional simulation approach for Fabry-Perot device structures is discussed. A three-dimensional (3-D) simulation of a device with a truncated contact shows the applicability of the simulator to complex laser cavity designs     

Winter wheat quantity or quality? Assessing food security in Uzbekistan

Winter wheat is the most important cereal in Uzbekistan. Although the processing industry recognizes the low quality of local wheat, the present land use policy prioritizes production quantity, and wheat of better quality is imported to improve local flour. Yet, with increasing world market prices, Uzbekistan has to decide whether to continue allocating considerable resources for imports or to start investing in local quality improvements. This study therefore analyzed wheat production in the Khorezm region of Uzbekistan by (a) assessing the economic feasibility of local production vs. imports; and by (b) evaluating the current N-fertilizer management at field level in order to identify options for improving quality. Demand for wheat in the region currently falls short of supply by 79,000 t but under favorable world market prices, funds for importing additional wheat could be covered by cotton sales. Prices above $148 USD t⁻¹ support the present land use policy to cultivate wheat but the baking quality of the crop is low. Higher N rates and/or an additional application of N at anthesis significantly increased grain quality. Additional costs for changes in N management, however, are currently not compensated by the price premiums at the State mills. Thus, in the absence of price incentives, it is unrealistic to expect producers to maximize quality production. Consequently, administrators must give quality greater attention by creating incentives through price differentials for higher quality, and encouraging awareness programs on wheat quality and improved on-field N management.     

Assessing the validity of a learning analytics expectation instrument: A multinational study

To assist higher education institutions in meeting the challenge of limited student engagement in the implementation of Learning Analytics services, the Questionnaire for Student Expectations of Learning Analytics (SELAQ) was developed. This instrument contains 12 items, which are explained by a purported two-factor structure of “Ethical and Privacy Expectations” and “Service Feature Expectations.” As it stands, however, the SELAQ has only been validated with students from UK university, which is problematic on account of the interest in Learning Analytics extending beyond this context. Thus, the aim of the current work was to assess whether the translated SELAQ can be validated in three contexts (an Estonian, a Spanish, and a Dutch University). The findings show that the model provided acceptable fits in both the Spanish and Dutch samples, but was not supported in the Estonian student sample. In addition, an assessment of local fit is undertaken for each sample, which provides important points that need to be considered in future work. Finally, a general comparison of expectations across contexts is undertaken, which are discussed in relation to the General Data Protection Regulation (2018).     

Cell therapeutic options in liver diseases: cell types,medical devices and regulatory issues

Although significant progress has been made in the field of orthotopic liver transplantation, cell-based therapies seem to be a promising alternative to whole-organ transplantation. The reasons are manifold but organ shortage is the main cause for this approach. However, many problems such as the question which cell type should be used or which application site is best for transplantation have been raised. In addition, some clinicians have had success by cultivating liver cells in bioreactors for temporary life support. Besides answering the question which cell type, which injection site or even which culture form should be used for liver support recent international harmonization of legal requirements is needed to be addressed by clinicians, scientists and companies dealing with cellular therapies. We here briefly summarize the possible cell types used to partially or temporarily correct liver diseases, the most recent development of bioreactor technology and important regulatory issues.