Search Results - (Author, Cooperation:C. Kramer)

2011-08-13

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

2018-11-07

Genetics Society of America (GSA)

2160-1836

Biology

2018-12-15

The American Association for Cancer Research (AACR)

1078-0432

1557-3265

Medicine

book

2010

Bildung ; Kultur ; Natur ; Siedlungsstruktur ; Stadt ; Stadtentwicklung ; Bevölkerungsentwicklung ; Internationale Beziehungen ; Staat ; Umwelt ; Erwerbstätigkeit ; Markt ; Unternehmen ; Statistik ; Alltag ; Infrastruktur ; Bevölkerung

German

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

Collisions of excited 113Cd(5 3P1) atoms with various molecular gases (N2, H2, D2, CO, CO2, CH4, C2H6, C2H4, O2) have been investigated using atomic fluorescence spectroscopy. By selective excitation of a hyperfine structure level with a pulsed dye laser and studying the time dependence of the fluorescence signals as a function of the buffer gas density the cross sections for quenching, fine structure transfer, and hyperfine structure transfer could be obtained. For N2 molecules the collisions can be described by a decoupling model as has been shown previously for the noble gases as collision partners.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

We report on multijunction GaInP/GaAs photovoltaic cells with efficiencies of 29.5% at 1-sun concentration and air mass (AM) 1.5 global and 25.7% 1-sun, AM0. These values represent the highest efficiencies achieved by any solar cell under these illumination conditions. Three key areas in this technology are identified and discussed; the grid design, front surface passivation of the top cell, and bottom surface passivation of both cells. Aspects of cell design related to its operation under concentration are also discussed.

Electronic Resource

1365-2958

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Medicine

P fimbriae of the F71 serotype of Escherichia coli are composed of a major subunit, FsoA, and of three minor proteins named FsoG, FsoE, and FsoF. FsoG is the Galα(1–4)Gal-specific lectin. We assessed mutated recombinant strains each deficient in one fimbrial component for adhesion to frozen sections of rat cortical kidney and to fibronectin immobilized on glass. Rat kidney lacks the Galα(1–4)Gal-containing glycolipids. The fsoG mutant strain was as adhesive to sections of rat kidney and to fibronectin-coated glass as was the recombinant strain expressing the complete fso gene cluster. The fsoA mutant strain was highly adhesive to fibronectin and to kidney sections. In the rat kidney, the adhesion of these strains was predominantly localized to sites of basolateral membranes of tubuli. The fsoE and the fsoF mutant strains were slightly less adhesive to kidney structures and failed to adhere to fibronectin. The fsoE, fsoF double mutant strain adhered neither to fibronectin nor to kidney sections. None of the fso recombinant strains reacted with soluble fibronectin, suggesting that the interaction is dependent on the conformation of the fibronectin molecules. Recombinant strains expressing the F72, F8, F11, F13, and F14 serovariants of the P fimbria also showed adherence to immobilized fibronectin. The results show that in addition to binding to globoseries of glycolipids via the G protein, the P fimbriae of uropathogenic E. coli exhibit a tissue-binding property influenced by fsoE and fsoF gene products and with affinity for basolateral membranes and fibronectin.

Electronic Resource

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Rodlet cells within the epithelial mucosa of the gall bladder of the estuarine killifish Fundulus heteroclitus (L.) obtained from a highly contaminated creek adjacent to a landfill, were arranged within the constraints of the epithelium. Furthermore, the rodlet cells established a close intimate association with electron dense epithelioid cells. A comparison with fish from a non impacted estuary revealed a significantly greater number of rodlet cells in the ‘contaminated’ group. The abundance of rodlet cells within the gall bladder of the fish exposed to contaminants further strengthens the hypothesis that these cells participate in the fish's immune system.

Electronic Resource

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Rodlet cells occurred in the posterior intestine of embryos and neonates of the swordtail Xiphophorus nigrensis, its hybrids with Xiphophorus pygmaeus and in the platyfish Xiphophorus maculatus. This is the first observation of these enigmatic cells in a viviparous teleost prior to birth. This finding lends support to the endogenous tenet regarding the origin of this cell.

Electronic Resource

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

The effects of thrice weekly injections of Ovaprim (sGnRH-A in combination with domperidone) on the ovary of Thalassoma bifasciatum, a protogynous marine fish, after 4 and 6 weeks are described. At the end of 4 weeks of treatment, 72% (n=13) of the original females showed signs of reversal. The majority of these were deemed early stage although mid- (n=2) and late (n=1) stage reversals were present. At 6 weeks, 92% of the females had ovaries that were undergoing transformation. None of these, however, progressed beyond the early stage. Only 3.8% of the control fish showed signs of reversal over the same periods. The blue head colour pattern, typical of the terminal phase, did not appear in any of the fish.To our knowledge, this is the first report investigating the hypothalamic influence on sex reversal in T. bifasciatum. These observations shed new light on the neuroendocrine control of reversal of gender in this species and hermaphroditic fishes in general.

Electronic Resource

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

The effects of exogenous testosterone pellet implants at 21 and 40 days on the ovary of Thalassoma bifasciatum, a protogynous marine fish, are described. The characteristic markings of the terminal blue phase appeared by 4 to 5 days and were complete by 18 days. There was no shift in sex ratio in the treated fish when compared to an untreated control group. None of the ovaries showed signs of precocious transformation, i.e., spermatogenic tissue was lacking, and there was no evidence of duct formation. Instead, however, the ovaries of the treated fish showed marked degenerative changes characterized by oocyte breakdown, fat infiltration, vacuolization, the accumulation of fibrous PAS+ material and the appearance of small eosinophilic cells.These findings conflict with earlier studies on the same organism that employed different procedures. However, they resemble more closely the results obtained from work on another protogynoid, the ricefield eel, Monopterus albus. They add new light on the role of sex hormones in the reversal process of T. bifasciatum and hermaphroditic fishes in general.

Electronic Resource

0028-2677

Linguistics and Literary Studies

0028-2677

Linguistics and Literary Studies

0028-2677

Linguistics and Literary Studies

0028-2677

Linguistics and Literary Studies

0028-2677

Linguistics and Literary Studies

0378-1119

Recombinant DNA ; amdS'.'.lacZ fusion gene ; carbon catabolite repression ; nitrogen metabolite repression ; targeted single-copy integration ; ω-amino acid induction

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Electronic Resource

0301-0511

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Psychology

Electronic Resource

0921-4534

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0921-4534

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource