Real surface effects on radiative heat transfer

Radiative heat transfer for system of radiatively interacting opaque surfaces separated by radiatively transparent mediu

Theoretical study of radiant heat exchange for non-gray non-diffuse surfaces in a space environment Semiannual status report no. 3, Feb. - Jul. 1966

Radiant heat exchange for nongray nondiffuse surfaces in space environmen

Theoretical Study of Radiant Heat Exchange for Non-gray Non-diffuse Surfaces in a Space Environment Semiannual Status Report No. 2, Aug. 1965 - Feb. 1966

Bi-directional reflectance models for describing distribution of reflected energy from rough metallic spacecraft surface

Radiant heat exchange in a space environment Scientific technical report, 1 Feb. - 31 Jul. 1970

Spectral and directional surface property effects on radiant heat transfer in space environmen

Radiant heat exchange in a space environment Scientific technical report, 1 Aug. 1969 - 31 Jan. 1970

Spectral surface property effects on radiant heat transfer in aerospace environmen

Radiant heat exchange in a space environment Scientific technical report, 1 Feb. - 31 Jul. 1969

Analytical methods development for predicting radiant heat transfer and temperature of engineering surfaces in space environmen

Penrose-Pflasterungen in der Architektur - die künstlerische Umsetzung eines mathematischen Modells im Gemeindeverwaltungs-Zentrum von Bütgenbach, Belgien

Der englische Physiker und Mathematiker Roger Penrose hat eine mathematische Pflasterung entdeckt, deren Formenreichtum neue Impulse in der Architektur setzen kann. In der Gemeinde Bütgenbach im Hohen Venn, Belgien, wurde das Verwaltungszentrum durch den Essener Architekten Ernst Burghartz mit mehrereren Penrose-Pflasterungen versehen. Diese beruhen auf einem Computer-Programm, welches der Vortragende zusammen mit Dr. Frank Martini entwickelt hat. Herr Burghartz hat jedoch diesen Vorentwurf nach seinen künstlerischen Vorstellungen abgewandelt

Experimental Characterization of Cis-Acting Elements Important for Translation and Transcription in Halophilic Archaea

The basal transcription apparatus of archaea is well characterized. However, much less is known about the mechanisms of transcription termination and translation initation. Recently, experimental determination of the 5′-ends of ten transcripts from Pyrobaculum aerophilum revealed that these are devoid of a 5′-UTR. Bioinformatic analysis indicated that many transcripts of other archaeal species might also be leaderless. The 5′-ends and 3′-ends of 40 transcripts of two haloarchaeal species, Halobacterium salinarum and Haloferax volcanii, have been determined. They were used to characterize the lengths of 5′-UTRs and 3′-UTRs and to deduce consensus sequence-elements for transcription and translation. The experimental approach was complemented with a bioinformatics analysis of the H. salinarum genome sequence. Furthermore, the influence of selected 5′-UTRs and 3′-UTRs on transcript stability and translational efficiency in vivo was characterized using a newly established reporter gene system, gene fusions, and real-time PCR. Consensus sequences for basal promoter elements could be refined and a novel element was discovered. A consensus motif probably important for transcriptional termination was established. All 40 haloarchaeal transcripts analyzed had a 3′-UTR (average size 57 nt), and their 3′-ends were not posttranscriptionally modified. Experimental data and genome analyses revealed that the majority of haloarchaeal transcripts are leaderless, indicating that this is the predominant mode for translation initiation in haloarchaea. Surprisingly, the 5′-UTRs of most leadered transcripts did not contain a Shine-Dalgarno (SD) sequence. A genome analysis indicated that less than 10% of all genes are preceded by a SD sequence and even most proximal genes in operons lack a SD sequence. Seven different leadered transcripts devoid of a SD sequence were efficiently translated in vivo, including artificial 5′-UTRs of random sequences. Thus, an interaction of the 5′-UTRs of these leadered transcripts with the 16S rRNA could be excluded. Taken together, either a scanning mechanism similar to the mechanism of translation initiation operating in eukaryotes or a novel mechanism must operate on most leadered haloarchaeal transcripts

Effects of Circulating and Local Uteroplacental Angiotensin II in Rat Pregnancy.

The renin-angiotensin (Ang) system is important during placental development. Dysregulation of the renin-Ang system is important in preeclampsia (PE). Female rats transgenic for the human angiotensinogen gene crossed with males transgenic for the human renin gene develop the PE syndrome, whereas those of the opposite cross do not. We used this model to study the role of Ang II in trophoblast invasion, which is shallow in human PE but deeper in this model. We investigated the following groups: PE rats, opposite-cross rats, Ang II–infused rats (1000 ng/kg per day), and control rats. Ang II infusion increased only circulating Ang II levels (267.82 pg/mL), opposite cross influenced only uteroplacental Ang II (13.52 fmol/mg of protein), and PE increased both circulating (251.09 pg/mL) and uteroplacental (19.24 fmol/mg of protein) Ang II. Blood pressure and albuminuria occurred in the models with high circulating Ang II but not in the other models. Trophoblast invasion increased in PE and opposite-cross rats but not in Ang II–infused rats. Correspondingly, uterine artery resistance index increased in Ang II–infused rats but decreased in PE rats. We then studied human trophoblasts and villous explants from first-trimester pregnancies with time-lapse microscopy. Local Ang II dose-dependently increased migration by 75%, invasion by 58%, and motility by 282%. The data suggest that local tissue Ang II stimulates trophoblast invasion in vivo in the rat and in vitro in human cells, a hitherto fore unrecognized function. Conceivably, upregulation of tissue Ang II in the maternal part of the placenta represents an important growth factor for trophoblast invasion and migration