Growth direction dependent separate-channel charge transport in organic weak charge-transfer co-crystal of anthracene-DTTCNQ

Co-crystallization is an efficient way of molecular crystal engineering to tune the electronic properties of organic semiconductors. In this work, we synthesized anthracene-4,8-bis(dicyanomethylene)4,8-dihydrobenzo[1,2-b:4,5-b’]-dithiophene (DTTCNQ) single crystals as a template to...

Early Statehood and Support for Autocratic Rule in Africa

Recent work highlights the importance of pre-modern political practices for explaining persistent institutional features, including representative democracy. Typically, this argument is institutional in nature—pre-industrial practices are hypothesized to either bolster or retard the transmission of democratic institutions. This article proposes a separate channel through which legacies of early statehood continue to impact the prospects of democratic governance. Using survey data from Africa, we document a positive relationship between early statehood development and support for autocratic rule among ordinary Africans. This finding is robust to a wide range of pre- and post-treatment covariates, country and survey round fixed effects, as well as an instrumental-variable design. The identified relationship is particularly prominent in respondents from precolonially centralized ethnic groups in former British colonies, suggesting the importance of locally surviving traditional institutions for propagation of norms that owe their origins to precolonial autocratic socialization.

The human TRPA1 intrinsic cold and heat sensitivity involves separate channel structures beyond the N-ARD domain

The human TRPA1 (hTRPA1) is an intrinsic thermosensitive ion channel responding to both cold and heat, depending on the redox environment. Here, we have studied purified hTRPA1 truncated proteins to gain further insight into the temperature gating of hTRPA1. We found in patch-clamp bilayer recordings that Δ1-688 hTRPA1, without the N-terminal ankyrin repeat domain (N-ARD), was more sensitive to cold and heat, whereas Δ1-854 hTRPA1 that is also lacking the S1-S4 voltage sensing-like domain (VSLD) gained sensitivity to cold but lost its heat sensitivity. The thiol reducing agent TCEP abolished the temperature sensitivity of both Δ1-688 hTRPA1 and Δ1-854 hTRPA1. Cold and heat activity of Δ1-688 hTRPA1 and Δ1-854 hTRPA1 were associated with different structural conformational changes as revealed by intrinsic tryptophan fluorescence measurements. Heat evoked major structural rearrangement of the VSLD as well as the C-terminus domain distal to the transmembrane pore domain S5-S6 (CTD), whereas cold only caused minor conformational changes. As shown for Δ1-854 hTRPA1, a sudden drop in tryptophan fluorescence occurred within 25-20°C indicating a transition between heat and cold conformations of the CTD, and thus it is proposed that the CTD contains a bidirectional temperature switch priming hTRPA1 for either cold or heat. In whole-cell patch clamp electrophysiology experiments, replacement of the cysteines 865, 1021 and 1025 with alanine modulated the cold sensitivity of hTRPA1 when heterologously expressed in HEK293T cells. It is proposed that the hTRPA1 CTD harbors cold and heat sensitive domains allosterically coupled to the S5-S6 pore region and the VSLD, respectively.

Measuring the Quality of Money

This article explains the theoretical importance of the quality of money as a factor of the demand for money and develops the composite indicator that measures the quality of money for the eurozone. The demand for money, i.e., the amount of money people keep in their balances, besides other well-known factors (e.g., interest rate, price level, and income) depends on how people subjectively perceive a particular money’s ability to serve its main functions: a medium of exchange, a store of value, and the unit of account. These properties depend not only on the instruments of monetary policy and the extent to which they are used, but also on the institutional framework of the monetary system. The article suggests that the quality of money is influenced by the institutional framework and monetary policy and that thus the quality of money is a separate channel for the transmission of money policy that works not through the usual mechanism of changing the supply of money, but through central banks affecting the demand for money. An important contribution of this article is that it develops an empirical composite indicator, which measures the quality of money in the eurozone in 1999–2019 and shows the gradual decline in the quality of euro.

Validation activities for the Ice, Cloud, and Land Elevation Satellite - 2 (ICESat-2) Mission

<p>After launching on 15 September 2018, the Ice, Cloud, and Land Elevation Satellite – 2 (ICESat-2) Mission began collecting data on 14 October 2018.  The mission uses green laser light emitted by the Advanced Topographic Laser Altimetry System (ATLAS) to detect individual photons that are reflected by the Earth’s surface and returned to ATLAS.  These photons, when combined with information on the pointing direction, and position of the observatory in space, provide a geolocation and elevation for every measurement that spans the globe from 88 degrees north latitude to 88 degrees south.  The Global Geolocated Photon data product provides a latitude, longitude, elevation, and measurement time for each photon event telemetered to Earth for each of the instrument’s six beams. This product also delineates between high, medium, and low signal confidence levels and those measurements associated with background noise. The higher level, along-track products each use different strategies for photon aggregation to optimize the precision and accuracy of the surface retrievals over specific surface types. These types include land ice, sea ice, vegetation/land, ocean, and inland water. There is a separate channel dedicated to atmospheric returns to measure cloud and aerosols over a vertical window of 15 km. Calibration efforts utilized well designed on-orbit maneuvers to identify both pointing and range biases attributed to orbital variations on the satellite. Once corrected, the science-quality data products were released to the public in May 2019.</p><p> </p><p>In this presentation, we will present our ongoing work to evaluate and validate the geolocation and elevation accuracy and precision of measurements provided by the ICESat-2 mission.  The approaches are diverse in both location and methodology to ensure that we have a comprehensive assessment of the ATLAS performance variations throughout the orbital cycles. These strategies include comparisons with ground-based and airborne elevation measurements over the ice sheets, detailed analysis of returns from well-surveyed corner cube retro-reflectors, comparison of sea ice freeboard measured by airborne lidars, evaluation of global-scale ocean elevation through comparison with radar altimeters, and comparison of vegetation canopy height metrics measured by airborne lidar.  Our work to date demonstrates that individual photon elevations are accurate to approximately 30 cm vertically, and 6 m radially.  Aggregating many photons together reduces the elevation uncertainty to less than 5 cm for relatively flat and smooth ice sheet interiors.</p>

Near-Electrode Plasma at Electrolyte Discharge on the Frequency Selective Surface

Near-cathode plasma of the discharge in electrolyte and its interaction with electrodes was researched in the work. Electrical parameters of the discharge for two electrolyte compositions were investigated. Temperature and concentration of the near-cathode plasma of this discharge were measured using spectral methods. Appearance of sphere-like formations and pores surface is observed on the surface of the titanium electrodes. Possible explanation of the formation of these superface structures is proposed. The effect of the discharge in the electrolyte on the electrode surface was studied in this work. We consider properties of electrical current near the titanium electrode due to the presence a pores structure on this electrode. We can suppose that the current near the surface of cathode consists from a number of separate current channels with the 0.1-2 μm thick at a current in the region 10-8-10-6 А in the separate channel.

Knickpoints in Martian channels indicate past ocean levels

On Mars, the presence of extensive networks of sinuous valleys and large channels provides evidence for a wetter and warmer environment where liquid water was more abundant than it is at present. We undertook an analysis of all major channel systems on Mars and detected sharp changes in elevation along the river long profiles associated with steep headwall theatre-like valleys and terraces left downstream by channel incision. These breaks in channel longitudinal slope, headwalls and terraces exhibit a striking resemblance with terrestrial fluvial features, commonly termed ‘knickpoints’. On Earth, such knickpoints can be formed by more resistant bedrock or where changes in channel base-level have initiated erosion that migrates upstream (such as tectonic uplift or sea level change). We observed common elevations of Martian knickpoints in eleven separate channel systems draining into the Martian Northern lowlands. Numerical modeling showed that the common elevations of some of these knickpoints were not random. As the knickpoints are spread across the planet, we suggest that these Martian knickpoints were formed in response to a common base level or ocean level rather than local lithology. Thus, they potentially represent a record of past ocean levels and channel activity on Mars.

A New Coding Paradigm for the Primitive Relay Channel

We consider the primitive relay channel, where the source sends a message to the relay and to the destination, and the relay helps the communication by transmitting an additional message to the destination via a separate channel. Two well-known coding techniques have been introduced for this setting: decode-and-forward and compress-and-forward. In decode-and-forward, the relay completely decodes the message and sends some information to the destination; in compress-and-forward, the relay does not decode, and it sends a compressed version of the received signal to the destination using Wyner–Ziv coding. In this paper, we present a novel coding paradigm that provides an improved achievable rate for the primitive relay channel. The idea is to combine compress-and-forward and decode-and-forward via a chaining construction. We transmit over pairs of blocks: in the first block, we use compress-and-forward; and, in the second block, we use decode-and-forward. More specifically, in the first block, the relay does not decode, it compresses the received signal via Wyner–Ziv, and it sends only part of the compression to the destination. In the second block, the relay completely decodes the message, it sends some information to the destination, and it also sends the remaining part of the compression coming from the first block. By doing so, we are able to strictly outperform both compress-and-forward and decode-and-forward. Note that the proposed coding scheme can be implemented with polar codes. As such, it has the typical attractive properties of polar coding schemes, namely, quasi-linear encoding and decoding complexity, and error probability that decays at super-polynomial speed. As a running example, we take into account the special case of the erasure relay channel, and we provide a comparison between the rates achievable by our proposed scheme and the existing upper and lower bounds.