Newly synthesized proteins are degraded by an ATP-stimulated proteolytic process in isolated pea chloroplasts

AbstractUp to 22% of the [3H]leucine-labeled proteins synthesized chloroplasts in the light was degraded during subsequent incubation for 20–40 min. The degradation of these radioactive proteins was more rapid in the light than in the dark and was at least 2-fold greater in the presence of 5 mM ATP in light or darkness. Exogenous amino acids did not influence degradation rates, although they promoted protein synthesis. Overall, proteins from thylakoid and stromal fractions were degraded at comparable rates. Analysis by electrophoresis in denaturing polyacrylamide gels revealed that many proteins decreased in both fractions. Certain low molecular mass stromal proteins were lost almost completely during a 90 min incubation in the presence of ATP, while others were unaffected or decreased only slightly. Thus Chloroplasts, like eukaryotic and prokaryotic cells and mithochondria, contain an ATP-stimulated proteolytic system

GeoNEX: A Cloud Gateway for Near Real-time Processing of Geostationary Satellite Products

The emergence of a new generation of geostationary satellite sensors provides land andatmosphere monitoring capabilities similar to MODIS and VIIRS with far greater temporal resolution (5-15 minutes). However, processing such large volume, highly dynamic datasets requires computing capabilities that (1) better support data access and knowledge discovery for scientists; (2) provide resources to enable real-time processing for emergency response (wildfire, smoke, dust, etc.); and (3) provide reliable and scalable services for the broader user community. This paper presents an implementation of GeoNEX (Geostationary NASA-NOAA Earth Exchange) services that integrate scientific algorithms with Amazon Web Services (AWS) to provide near realtime monitoring (~5 minute latency) capability in a hybrid cloud-computing environment. It offers a user-friendly, manageable and extendable interface and benefits from the scalability provided by Amazon Web Services. Four use cases are presented to illustrate how to (1) search and access geostationary data; (2) configure computing infrastructure to enable near real-time processing; (3) disseminate and utilize research results, visualizations, and animations to concurrent users; and (4) use a Jupyter Notebook-like interface for data exploration and rapid prototyping. As an example of (3), the Wildfire Automated Biomass Burning Algorithm (WF_ABBA) was implemented on GOES-16 and -17 data to produce an active fire map every 5 minutes over the conterminous US. Details of the implementation strategies, architectures, and challenges of the use cases are discussed

Essential role for interleukin-2 for CD4+CD25+ T regulatory cell development during the neonatal period

Although many aspects of CD4+CD25+ T regulatory (Treg) cell development remain largely unknown, signaling through the IL-2R represents one feature for the production of Treg cells. Therefore, the present study was undertaken to further define early developmental steps in the production of Treg cells, including a more precise view on the role of interleukin (IL)-2 in this process. After adoptive transfer of wild-type Treg cells into neonatal IL-2Rβ−/− mice, only a small fraction of donor Treg cells selectively seeded the lymph node (LN). These donor Treg cells underwent rapid and extensive IL-2–dependent proliferation, followed by subsequent trafficking to the spleen. Thus, IL-2 is essential for Treg cell proliferation in neonatal LN. The number and distribution of Treg cells in the periphery of normal neonatal mice closely paralleled that seen for IL-2Rβ−/− mice that received Treg cells. However, for normal neonates, blockade of IL-2 decreased Treg cells in both the thymus and LN. Therefore, two steps of Treg cell development depend upon IL-2 in neonatal mice, thymus production, and subsequent expansion in the LN

Hydrodynamic fluctuations in the Kolmogorov flow: Linear regime

The Landau-Lifshitz fluctuating hydrodynamics is used to study the statistical properties of the linearized Kolmogorov flow. The relative simplicity of this flow allows a detailed analysis of the fluctuation spectrum from near equilibrium regime up to the vicinity of the first convective instability threshold. It is shown that in the long time limit the flow behaves as an incompressible fluid, regardless of the value of the Reynolds number. This is not the case for the short time behavior where the incompressibility assumption leads in general to a wrong form of the static correlation functions, except near the instability threshold. The theoretical predictions are confirmed by numerical simulations of the full nonlinear fluctuating hydrodynamic equations.Comment: 20 pages, 4 figure

Highly Dispersive Spin Excitations in the Chain Cuprate Li2CuO2

We present an inelastic neutron scattering investigation of Li2CuO2 detecting the long sought quasi-1D magnetic excitations with a large dispersion along the CuO2-chains studied up to 25 meV. The total dispersion is governed by a surprisingly large ferromagnetic (FM) nearest-neighbor exchange integral J1=-228 K. An anomalous quartic dispersion near the zone center and a pronounced minimum near (0,0.11,0.5) r.l.u. (corresponding to a spiral excitation with a pitch angle about 41 degree point to the vicinity of a 3D FM-spiral critical point. The leading exchange couplings are obtained applying standard linear spin-wave theory. The 2nd neighbor inter-chain interaction suppresses a spiral state and drives the FM in-chain ordering below the Ne'el temperature. The obtained exchange parameters are in agreement with the results for a realistic five-band extended Hubbard Cu 3d O 2p model and L(S)DA+U predictions.Comment: 6 pages, 4 figures, submitted to Europhys. Let

A Study of the Rate of Growth of Two Sclerotized Regions within Larvae of Four Species of Mosquitoes

Author Institution: Department of Zoology and Entomology, The Ohio State University, Columbus, Ohi