Implementation of Multimodal Tracking Capabilities for High-Altitude Ballooning

Successful ballooning tracking is a challenging task for many ballooning teams. Several methods of ballooning tracking are known to the ballooning community. In this paper, we present a concept of dual-modal tracking payload integrating an RF radio operating at ~900 MHz and a cellphone-based tracking system operating at ~2 GHz. In particular, we describe how we combined the RF-based and cellphone-based methods to function properly as an integrated module. As part of the implementation details, we also present a processing mechanism implemented on a microcontroller to detect when the payload has landed and turn on the cellphone after landing

Implementation of Simultaneous Multi-Streaming of Live Solar Eclipse Video via 5.8 GHz AirMax

For the 2017 solar eclipse ballooning, we have developed a video payload that can simultaneously live-stream multiple videos via a single 5.8 GHz wireless link. In this paper, we describe our approach to multiplex multiple video streams into a single data stream that a 5.8 GHz wireless modem can transport to the ground station. Various key factors are described to properly configure the Raspberry Pi’s and optimize the transmission from an M5 on the video payload over the 5.8 GHz link while ensuring adequate range and acceptable video quality received at the ground station. A screenshot of the multi-video streaming is provided as an example to justify a successful operation of our video payload

A fehérjemátrix szerepe a redoxfehérjék működésében = Role of the protein matrix in the function of redox proteins

Rekombináns citokróm c mutánsokat állítottunk elő és a bevezetett ciszteineket TUPS fotoaktív redox jelölővel jelöltük. Ugyancsak jelöltünk felszíni lizineket. Lézerimpulzussal való gerjesztés után kinetikus spektroszkópiai módszerrel mértük és értelmeztük az elektrontranszfer sebességét a jelölő és a citokróm hem kofaktora között. Megállapítottuk, hogy a jelölő flexibilis kovalens kapcsolata miatt több pozíciót tud felvenni és ezért az elektrontranszfer több exponenciálisból álló kinetikát mutat. A kísérleti adatokat összehasonlítottuk modellszámításokkal és megállapítottuk, hogy mind a konkrét elektrontranszfer útvonalakkal, mind pedig a fehérjével, mint változó sűrűségű folytonos közeggel számoló modell az eredményekkel jól megegyező sebességeket jósol. A citokróm felszínét feltérképeztük elektrontranszfer hatékonyság szempontjából: a hem síkjához viszonyított poláros régiók valamivel hatékonyabbak az egyenlítői régióknál. A citokróm c és a citokróm oxidáz komplexében mérve az elektrontranszfert az eddigieknél nagyobb időfelbontással tudtuk megmérni a CuA (első) elektronakceptor redukciójának idejét, és azt 100 ns-nál gyorsabbnak találtuk. Megállapítottuk, hogy E. coli baktériumban érett holocitokróm c kis mennyiségben spontán módon, hem liáz segítsége nélkül is képződik. Sikerült a hem liáz fehérjét heterológ módon kifejezni és tisztítani, és így apocitokróm és hem felhasználásával in vitro holocitokrómot termelni. | We produced recombinant mutant cytochrome c proteins and labeled the introduced cysteines and native lysines with the photoactive redox label TUPS. Pulse laser excitation of TUPS and the ensuing electron transfer between the label and the heme of cytochrome c was followed by kinetic absorption spectroscopy. Due to the flexible covalent link between the label and the protein TUPS can assume multiple positions which result in multiexponential electron transfer kinetics. We compared the experimental data with model calculations and concluded that both the model assuming explicite electron transfer pathways and the model assuming a protein matrix with varying packing density can satisfactorily describe the experimental observations. We mapped the surface of cytochrome c in terms of electron transfer efficiency towards the heme. The polar regions were found to be slightly more efficient ('hotter') than the equatorial regions relative to the plane of the heme. By measuring the electron transfer in the complex of cytochrome c and cytochrome c oxidase at a higher time resolution than in previous studies, we obtained a reduction time of the primary electron acceptor, CuA, which is faster than 100 ns. We found that in E. coli a low efficiency spontaneous maturation of holocytochrome c can take place without the assistance of heme lyase. We expressed and purified yeast heme lyase from E. coli and demonstrated in vitro holocytochrome maturation upon addition of apocytochrome and heme

Mapping local electric fields in proteins at biomimetic interfaces

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.We present a novel approach for determining the strength of the electric field experienced by proteins immobilised on membrane models. It is based on the vibrational Stark effect of a nitrile label introduced at different positions on engineered proteins and monitored by surface enhanced infrared absorption spectroscopy

ApoE−/− PGC-1α−/− Mice Display Reduced IL-18 Levels and Do Not Develop Enhanced Atherosclerosis

BACKGROUND: Atherosclerosis is a chronic inflammatory disease that evolves from the interaction of activated endothelial cells, macrophages, lymphocytes and modified lipoproteins (LDLs). In the last years many molecules with crucial metabolic functions have been shown to prevent important steps in the progression of atherogenesis, including peroxisome proliferator activated receptors (PPARs) and the class III histone deacetylase (HDAC) SIRT1. The PPARγ coactivator 1 alpha (Ppargc1a or PGC-1α) was identified as an important transcriptional cofactor of PPARγ and is activated by SIRT1. The aim of this study was to analyze total PGC-1α deficiency in an atherosclerotic mouse model. METHODOLOGY/PRINCIPAL FINDINGS: To investigate if total PGC-1α deficiency affects atherosclerosis, we compared ApoE(-/-) PGC-1α(-/-) and ApoE(-/-) PGC-1α(+/+) mice kept on a high cholesterol diet. Despite having more macrophages and a higher ICAM-1 expression in plaques, ApoE(-/-) PGC-1α(-/-) did not display more or larger atherosclerotic plaques than their ApoE(-/-) PGC-1α(+/+) littermates. In line with the previously published phenotype of PGC-1α(-/-) mice, ApoE(-/-) PGC-1α(-/-) mice had marked reduced body, liver and epididymal white adipose tissue (WAT) weight. VLDL/LDL-cholesterol and triglyceride contents were also reduced. Aortic expression of PPARα and PPARγ, two crucial regulators for adipocyte differentiation and glucose and lipid metabolism, as well as the expression of some PPAR target genes was significantly reduced in ApoE(-/-) PGC-1α(-/-) mice. Importantly, the epididymal WAT and aortic expression of IL-18 and IL-18 plasma levels, a pro-atherosclerotic cytokine, was markedly reduced in ApoE(-/-) PGC-1α(-/-) mice. CONCLUSIONS/SIGNIFICANCE: ApoE(-/-) PGC-1α(-/-) mice, similar as PGC-1α(-/-) mice exhibit markedly reduced total body and visceral fat weight. Since inflammation of visceral fat is a crucial trigger of atherogenesis, decreased visceral fat in PGC-1α-deficient mice may explain why these mice do not develop enhanced atherosclerosis