Regional Comprehensive Economic Partnership (RCEP) on agricultural products

Intra-industry trade plays an important role in the current international economics literature. In 2019, Indonesia's total exports to RCEP member countries reached 61.65% of Indonesia's total exports, and 44% of total exports to RCEP came from the agricultural sector. The purpose of this research is to examine the interdependence of Indonesia and its 14 trading partners in RCEP. This research uses secondary time series data from the trademap, namely the flow of Indonesian agricultural trade with RCEP countries from 2010-2019. The data analysis method in this study is the intra-industry trade index. The results of the study of trade patterns identified through the Indonesia-RCEP Trade Relations (IIT) show that the raw material with the highest average IIT value is processed flour (HS 19). This shows that Indonesia's RCEP trade in flour products (HS 19) is bilateral. In terms of country, Malaysia is a country with the strongest trade relations with Indonesia. The average score of 19.74 between IIT Indonesia and RCEP reflects that the relationship between Indonesian agricultural products and RCEP is still low and classified as inter-industry trade. The low IIT value may be due to the large one-way trade in RCEP, where Indonesia is still the dominant importer. Therefore, it is important for the government to further increase potential commodity exports by encouraging agricultural product processing industries with tax breaks within a certain period.

Probing the photointermediates of light-driven sodium ion pump KR2 by DNP-enhanced solid-state NMR

The functional mechanism of the light-driven sodium pump Krokinobacter eikastus rhodopsin 2 (KR2) raises fundamental questions since the transfer of cations must differ from the better-known principles of rhodopsin-based proton pumps. Addressing these questions must involve a better understanding of its photointermediates. Here, dynamic nuclear polarization-enhanced solid-state nuclear magnetic resonance spectroscopy on cryo-trapped photointermediates shows that the K-state with 13-cis retinal directly interconverts into the subsequent L-state with distinct retinal carbon chemical shift differences and an increased out-of-plane twist around the C14-C15 bond. The retinal converts back into an all-trans conformation in the O-intermediate, which is the key state for sodium transport. However, retinal carbon and Schiff base nitrogen chemical shifts differ from those observed in the KR2 dark state all-trans conformation, indicating a perturbation through the nearby bound sodium ion. Our findings are supplemented by optical and infrared spectroscopy and are discussed in the context of known three-dimensional structures

A subgroup of light-driven sodium pumps with an additional Schiff base counterion.

Light-driven sodium pumps (NaRs) are unique ion-transporting microbial rhodopsins. The major group of NaRs is characterized by an NDQ motif and has two aspartic acid residues in the central region essential for sodium transport. Here we identify a subgroup of the NDQ rhodopsins bearing an additional glutamic acid residue in the close vicinity to the retinal Schiff base. We thoroughly characterize a member of this subgroup, namely the protein ErNaR from Erythrobacter sp. HL-111 and show that the additional glutamic acid results in almost complete loss of pH sensitivity for sodium-pumping activity, which is in contrast to previously studied NaRs. ErNaR is capable of transporting sodium efficiently even at acidic pH levels. X-ray crystallography and single particle cryo-electron microscopy reveal that the additional glutamic acid residue mediates the connection between the other two Schiff base counterions and strongly interacts with the aspartic acid of the characteristic NDQ motif. Hence, it reduces its pKa. Our findings shed light on a subgroup of NaRs and might serve as a basis for their rational optimization for optogenetics

Mathematical Mobile Apps Via Rural Casting

This paper discusses the distribution, through a digital datacasting framework, of mathematical resources for Grades 1 to 7 to two schools in a community in the Philippines. Among the mathematical resources made available, are mathematical applications (apps), which run on mobile technologies, that have been created to help in the mathematical learning of students in a remote setting. The distribution is facilitated by the RuralCasting set-top box, a developed custom set-top box capable of receiving digital TV broadcasts and providing local content access through its Wi-Fi network. This paper presents the performance of the set-top box in distributing the mobile mathematical apps, and a short discussion on the mathematical applications deployed

Femtosecond-to-millisecond structural changes in a light-driven sodium pump

Light-driven sodium pumps actively transport small cations across cellular membranes1. These pumps are used by microorganisms to convert light into membrane potential and have become useful optogenetic tools with applications in neuroscience. Although the resting state structures of the prototypical sodium pump Krokinobacter eikastus rhodopsin 2 (KR2) have been solved2,3, it is unclear how structural alterations over time allow sodium to be translocated against a concentration gradient. Here, using the Swiss X-ray Free Electron Laser4, we have collected serial crystallographic data at ten pump–probe delays from femtoseconds to milliseconds. High-resolution structural snapshots throughout the KR2 photocycle show how retinal isomerization is completed on the femtosecond timescale and changes the local structure of the binding pocket in the early nanoseconds. Subsequent rearrangements and deprotonation of the retinal Schiff base open an electrostatic gate in microseconds. Structural and spectroscopic data, in combination with quantum chemical calculations, indicate that a sodium ion binds transiently close to the retinal within one millisecond. In the last structural intermediate, at 20 milliseconds after activation, we identified a potential second sodium-binding site close to the extracellular exit. These results provide direct molecular insight into the dynamics of active cation transport across biological membranes.ISSN:0028-0836ISSN:1476-468