A novel putative auxin carrier family regulates intracellular auxin homeostasis in plants

The phytohormone auxin acts as a prominent signal, providing, by its local accumulation or depletion in selected cells, a spatial and temporal reference for changes in the developmental program. The distribution of auxin depends on both auxin metabolism (biosynthesis, conjugation and degradation) and cellular auxin transport. We identified in silico a novel putative auxin transport facilitator family, called PIN-LIKES (PILS). Here we illustrate that PILS proteins are required for auxin-dependent regulation of plant growth by determining the cellular sensitivity to auxin. PILS proteins regulate intracellular auxin accumulation at the endoplasmic reticulum and thus auxin availability for nuclear auxin signalling. PILS activity affects the level of endogenous auxin indole-3-acetic acid (IAA), presumably via intracellular accumulation and metabolism. Our findings reveal that the transport machinery to compartmentalize auxin within the cell is of an unexpected molecular complexity and demonstrate this compartmentalization to be functionally important for a number of developmental processes.     

A comparison of official population projections with Bayesian time series forecasts for England and Wales

We compare official population projections with Bayesian time series forecasts for England and Wales. The Bayesian approach allows the integration of uncertainty in the data, models and model parameters in a coherent and consistent manner. Bayesian methodology for time-series forecasting is introduced, including autoregressive (AR) and stochastic volatility (SV) models. These models are then fitted to a historical time series of data from 1841 to 2007 and used to predict future population totals to 2033. These results are compared to the most recent projections produced by the Office for National Statistics. Sensitivity analyses are then performed to test the effect of changes in the prior uncertainty for a single parameter. Finally, in-sample forecasts are compared with actual population and previous official projections. The article ends with some conclusions and recommendations for future work.     

Hybrid aqueous capacitors with improved energy/power performance

This work reports on a high-voltage, hybrid capacitor involving two separate redox reactions. Aqueous solutions of Mg(NO3)2 and KI have been used for negative and positive electrode, respectively. Adjusting pH=2 for electrode (+) with KI solution and modifying Mg(NO3)2 solution to pH=9 for negative side play a crucial role for a stable long-term operation of capacitor at enhanced voltage. A benefit from such a construction is a pseudocapacitive contribution from hydrogen sorption reaction on the negative electrode and high iodine/iodide activity on the positive electrode, enhancing the energy with no remarkable impact on the power profile. Proposed solution allows a high voltage (1.8 V) to be reached and thereby high power and energy performance (~20 W h/kg at 1 kW/kg) to be obtained. High long-term stability has been confirmed by floating and galvanostatic tests.     

CAS directly interacts with vinculin to control mechanosensing and focal adhesion dynamics

Focal adhesions are cellular structures through which both mechanical forces and regulatory signals are transmitted. Two focal adhesion-associated proteins, Crk-associated substrate (CAS) and vinculin, were both independently shown to be crucial for the ability of cells to transmit mechanical forces and to regulate cytoskeletal tension. Here, we identify a novel, direct binding interaction between CAS and vinculin. This interaction is mediated by the CAS SRC homology 3 domain and a proline-rich sequence in the hinge region of vinculin. We show that CAS localization in focal adhesions is partially dependent on vinculin, and that CAS–vinculin coupling is required for stretch-induced activation of CAS at the Y410 phosphorylation site. Moreover, CAS–vinculin binding significantly affects the dynamics of CAS and vinculin within focal adhesions as well as the size of focal adhesions. Finally, disruption of CAS binding to vinculin reduces cell stiffness and traction force generation. Taken together, these findings strongly implicate a crucial role of CAS–vinculin interaction in mechanosensing and focal adhesion dynamics.     

New Cenozoic dragonflies from the Most Basin and Středohoří Complex volcanic area (Czech Republic,Germany)

Discovery of new dragonflies from Oligocene and Miocene deposits of the Most Basin and ?eské St?edoho?í Complex volcanic area in northern Bohemia and Saxony (Germany) is reported. Aeshna zlatkokvaceki sp. nov. is the first described dragonfly from early Miocene salmon-pink baked clays of ?elénky near Duchcov. Its fore wing venation pattern seems to be closely related to that of Aeshna turoliana Riou and Nel, 1995, known from late Miocene of La Montagne d’Andance in Ardèche, France, and Aeshna solida Scudder, 1890, known from late Eocene of Florissant in Colorado, USA. A new occurrence of a libellulid dragonfly ?Onychothemis rihai in the Libkovice Member of Most Basin confirms the links to the Cypris Formation in Sokolov and Cheb basins reflecting similar habitats as was already shown on the basis of reconstructed palaeovegetation and shared thermophilous and accessory floristic elements. Other fragmentary fossil material from different localities are discussed.

http://zoobank.org/urn:lsid:zoobank.org:pub:7A3BB1C3-5A70-4058-86A5-731B58C0ADC3     

Polar actomyosin contractility destabilizes the position of the cytokinetic furrow

Cytokinesis, the physical separation of daughter cells at the end of mitosis, requires precise regulation of the mechanical properties of the cell periphery. Although studies of cytokinetic mechanics mostly focus on the equatorial constriction ring, a contractile actomyosin cortex is also present at the poles of dividing cells. Whether polar forces influence cytokinetic cell shape and furrow positioning remains an open question. Here we demonstrate that the polar cortex makes cytokinesis inherently unstable. We show that limited asymmetric polar contractions occur during cytokinesis, and that perturbing the polar cortex leads to cell shape oscillations, resulting in furrow displacement and aneuploidy. A theoretical model based on a competition between cortex turnover and contraction dynamics accurately accounts for the oscillations. We further propose that membrane blebs, which commonly form at the poles of dividing cells and whose role in cytokinesis has long been enigmatic, stabilize cell shape by acting as valves releasing cortical contractility. Our findings reveal an inherent instability in the shape of the dividing cell and unveil a novel, spindle-independent mechanism ensuring the stability of cleavage furrow positioning.     

Assessing time series models for forecasting international migration: Lessons from the United Kingdom

Migration is one of the most unpredictable demographic processes. The aim of this article is to provide a blueprint for assessing various possible forecasting approaches in order to help safeguard producers and users of official migration statistics against misguided forecasts. To achieve that, we first evaluate the various existing approaches to modelling and forecasting of international migration flows. Subsequently, we present an empirical comparison of ex post performance of various forecasting methods, applied to international migration to and from the United Kingdom. The overarching goal is to assess the uncertainty of forecasts produced by using different forecasting methods, both in terms of their errors (biases) and calibration of uncertainty. The empirical assessment, comparing the results of various forecasting models against past migration estimates, confirms the intuition about weak predictability of migration, but also highlights varying levels of forecast errors for different migration streams. There is no single forecasting approach that would be well suited for different flows. We therefore recommend adopting a tailored approach to forecasts, and applying a risk management framework to their results, taking into account the levels of uncertainty of the individual flows, as well as the differences in their potential societal impact.     

Dynamics of Wicking

Ｍａｎｙｏｆｉｍｐｏｒｔａｎｔｐｈｙｓｉｃａｌａｎｄｃｈｅｍｉｃａｌｐｒｏｃｅｓｓｅｓａｒｅｂａｓｅｄｏｎｔｈｅｃａｐｉｌｌａｒｉｔｙ—ｓｐｏｎｔａｎｅｏｕｓｐｅｎｅｔｒａｔｉｏｎｏｆｌｉｑｕｉｄｉｎｔｏｔｈｅｐｏｒｏｕｓｓｙｓｔｅｍｓ.Ｃａｐｉｌｌａｒｙｐｒｉｎｃｉｐｌｅｓａｒｅｕｓｅｄｉｎｖａｒｉｏｕｓｂｒａｎｃｈｅｓ.Ｅｖｅｒｙｄａｙｗｅｃｏｍｅｉｎｔｏｃｏｎｔａｃｔｗｉｔｈｐｒａｃｔｉｃａｌｅｘａｍｐｌｅｓｏｆｗｉｃｋｉｎｇｐｒｏｃｅｓｓｅｓ.Ｍｏｓｔｏｆｔｈｅｓｅｐｒｏｃｅｓｓｅｓａｒｅ…