Synthetic beta-solenoid proteins with the fragment-free computational design of a beta-hairpin extension

The ability to design and construct structures with atomic level precision is one of the key goals of nanotechnology. Proteins offer an attractive target for atomic design, as they can be synthesized chemically or biologically, and can self-assemble. However the generalized protein folding and design problem is unsolved. One approach to simplifying the problem is to use a repetitive protein as a scaffold. Repeat proteins are intrinsically modular, and their folding and structures are better understood than large globular domains. Here, we have developed a new class of synthetic repeat protein, based on the pentapeptide repeat family of beta-solenoid proteins. We have constructed length variants of the basic scaffold, and computationally designed de novo loops projecting from the scaffold core. The experimentally solved 3.56 ˚A resolution crystal structure of one designed loop matches closely the designed hairpin structure, showing the computational design of a backbone extension onto a synthetic protein core without the use of backbone fragments from known structures. Two other loop designs were not clearly resolved in the crystal structures and one loop appeared to be in an incorrect conformation. We have also shown that the repeat unit can accommodate whole domain insertions by inserting a domain into one of the designed loops

Modeling the water demand on farms

The decreasing availability of water caused by depletion and climate change combined with a growing world population requires the productive use of water now and in the future. The young researcher group "AgroHyd" at the Leibniz-Institute for Agricultural Engineering Potsdam-Bornim (ATB) is currently modeling the water demand for agricultural processes at the farm scale and developing indicators to link the hydrological and agricultural perspectives. The aim of the group is to increase productivity in agriculture by raising water productivity in plant production and livestock farming. The effects of various agronomic measures, individual and in combination, on water productivity are assessed using several indicators. Scenarios of agricultural measures, climate and diets are used to test to what extent the water demand for food production will increase due to growing global change in different regions of the world

Anatomical correlates of cursoriality are compromised by body size and propensity to burrow in a group of small mammals (Lagomorpha)

Highly cursorial animals are specialised for fast, sustained running via specific morphological adaptations, notably including changes in limb segment length and mechanical advantage. Members of the order Lagomorpha (hares, rabbits and pikas) vary in cursorial ability; hares are generally highly cursorial, rabbits more frequently saltate, and pikas predominantly trot. Previous investigations of lagomorphs have identified anatomical trends correlated with this ‘cursoriality gradient’, however, the phylogenetic sampling of such investigations has been limited to three American species, namely the American pika (Ochotona princeps), brush rabbit (Sylvilagus bachmani), and black-tailed jackrabbit (Lepus californicus). Here, we expand the phylogenetic sample and body size range by including novel data from Australian samples of the European rabbit (Oryctolagus cuniculus) and European hare (L. europaeus), alongside unpublished data on the Eastern cottontail (S. floridanus). X-ray Computed Tomography and digital landmarking were used to capture proportions within the appendicular skeleton of ~ 40 specimens of each European species. In doubling the number of species studied, we find the previously-identified morphological gradients associated with cursorial behaviour are complicated when evaluated in the larger sample. The relative length and joint velocity of limbs was found to be lower than predicted in European rabbits and hares. Furthermore, we present a novel assessment of morphological integration in the lagomorph appendicular skeleton, finding between-limb covariation patterns that are generally similar to those of other mammals. Broadly, these results suggest cursoriality is only one of many selective forces driving lagomorph skeletal evolution, with variations in body size and fossoriality potentially having measurable impacts.Ellen M. Martin, Jesse W. Young, Connie D. Fellmann, Brian Kraatz, Emma Sherrat

Priorities for energy efficiency measures in agriculture.

This report provides a compilation of energy efficiency measures in agriculture, their opportunities and constraints to implement energy efficient agricultural systems across Europe as a result of the AGREE (Agriculture & Energy Efficiency) Coordination and Support Action funded by the 7th research framework of the EU (www.agree.aua.gr). The report dwells on earlier reports of the consortium, which listed potential energy efficiency measures (Project Deliverable 2.3: Energy Saving Measures in Agriculture – Overview on the Basis of National Reports) and identified trade-offs and win-win situations of various energy efficiency measures in agriculture (Project Deliverable 3.1: Economic and environmental analysis of energy efficiency measures in agriculture). It shows research gaps in crop production, greenhouse production, animal husbandry and system approaches, which can be regarded as priorities for energy efficiency measures in agriculture. The report is na important input for the strategic research agenda, which is one of the main outputs of the AGREE project

Grain Size And Cap Layer Effects On Electromigration Reliability Of Cu Interconnects: Experiments And Simulation

This paper combined experiments and simulation to investigate the grain size and cap layer effects on electromigration (EM) reliability of Cu interconnects. First the statistical distribution of EM lifetime and failure modes were examined for in laid Cu interconnects of large and small grain structures with two different cap layers of SiCN vs. CoWP. The CoWP cap was found to significantly improve the EM lifetime due to the suppression of the interfacial mass transport as a result of strengthening of the Cu/cap interface bonding. In addition, the grain size was observed to affect the EM reliability significantly, particularly for the CoWP capped structures. Resistance traces and failure analysis revealed two distinct failure modes: mode I with voids formed near the cathode via corner and mode II with voids formed in the trench several microns away from the cathode via. It was found that large grain size and strong cap interface reduced the mass transport rate and the void diffusion in the Cu line, leading to a longer EM lifetime and a higher proportion of mode II failures. A statistical simulation of EM lifetimes was also applied to Cu interconnects with grain structures generated by the Monte Carlo method. The simulation results for different grain sizes and cap interfaces are in good agreement with the experimental observations.Microelectronics Research Cente

Performative Work: Bridging Performativity and Institutional Theory in the Responsible Investment Field

Callon’s performativity thesis has illuminated how economic theories and calculative devices shape markets, but has been challenged for its neglect of the organizational, institutional and political context. Our seven-year qualitative study of a large financial data company found that the company’s initial attempt to change the responsible investment field through a performative approach failed because of the constraints posed by field practices and organizational norms on the design of the calculative device. However, the company was subsequently able to put in place another form of performativity by attending to the normative and regulative associations of the device. We theorize this route to performativity by proposing the concept of performative work, which designates the necessary institutional work to enable translation and the subsequent adoption of the device. We conclude by considering the implications of performative work for the performativity and the institutional work literatures

Radical cation salts of an unsymmetrical BEDT-TTF derivative: DIMET

A surprising fact in the structures of the organic superconductors (TMTSF)2 Cl04 and -β-(BEDT-TTF)2X (X=I3-, IBr2- and AuI2-) is that there exists a slight dimerisation of the donor molecules within the stacks of these radical cation salts. Therefore, the question arises whether a more pronounced dimerisation in organic radical salts of this type leads to stronger intra- and interstack interactions and to stronger couplings between the unpaired electrons. This might result in an increase of the transition temperature to superconductivity. A step in this direction is the preparation of "unsymmetrical" donors like DIMET, which was synthesized recently. This new donor was electrocrystallized by us in different solvents using tetrabutylammonium salts of various anions like ClO4-, ReO4-, NO3-, I3-, (AuI2)-, PF6-, ASF6- and SbF6- as electrolytes. With all these anions radical salts were obtained and in some cases even several crystallographic different phases

Observation of compositional domains within individual copper indium sulfide quantum dots

The origin of photoluminescence in copper indium sulfide (CIS) quantum dots (Qdots) has previously been ascribed to a donor-acceptor pair (DAP) recombination, with a crystal lattice defect implicated as the origin of the donor state. In this study, electron energy-loss spectroscopy (EELS) was used to observe defect-rich compositional domains within individual CIS Qdots, supporting a model of defect-state-mediated photoluminescence for these particles, and identifying them as an ideal model system for future study of lattice defects on Qdot properties

Universities and Pricing on Higher Education Markets

Markets and prices in higher education. When can we speak of markets, and when markets exist, how are prices set