FHR-1 binds to C-reactive protein and enhances rather than inhibits complement activation

Factor H (FH)-related protein 1 (FHR-1) is one of the five human factor H-related proteins, which share sequence and structural homology with the alternative pathway complement inhibitor FH. Genetic studies on disease associations and functional analyses indicate that FHR-1 enhances complement activation by co mpetitive inhibition of FH binding to some surfaces and immune proteins. We have recen tly shown that FHR-1 binds to pentraxin 3. Here, our aim was to investigate whether FH R-1 binds to another pentraxin, C-reactive protein (CRP), analyze the functional relevance of this interaction and study the role of FHR- 1 in complement activation and regulation. FHR- 1 did not bind to native, pentameric CRP but it bound strongly to monomeric CRP via its C-term inal domains. FHR-1 at high concentration competed with FH for CRP binding, indicating possible complement de -regulation also on this ligand. FHR-1 did not inhibi t regulation of solid phase C3 convertase by FH and did not inhibit terminal complement complex forma tion induced by zymosan. On the contrary, by binding C3b, FHR-1 allowed C3 convertase form ation and thereby enhanced complement activation. FHR-1/CRP interacti ons increased complement activ ation via the classical and alternative pathways on surfaces such as th e extracellular matrix and necrotic cells. Altogether, these results identify CRP as a lig and for FHR-1 and suggest that FHR-1 enhances rather than inhibits complement activation, wh ich may explain the protective effect of FHR-1 deficiency in age-related macular degeneration

Band Formation during Gaseous Diffusion in Aerogels

We study experimentally how gaseous HCl and NH_3 diffuse from opposite sides of and react in silica aerogel rods with porosity of 92 % and average pore size of about 50 nm. The reaction leads to solid NH_4Cl, which is deposited in thin sheet-like structures. We present a numerical study of the phenomenon. Due to the difference in boundary conditions between this system and those usually studied, we find the sheet-like structures in the aerogel to differ significantly from older studies. The influence of random nucleation centers and inhomogeneities in the aerogel is studied numerically.Comment: 7 pages RevTex and 8 figures. Figs. 4-8 in Postscript, Figs. 1-3 on request from author

Intraspecific Combinations of Flower and Leaf Volatiles Act Together in Attracting Hawkmoth Pollinators

Insects pinpoint mates, food and oviposition sites by olfactory cues. Recognizing and localizing a suitable target by olfaction is demanding. Odor sources emit characteristic blends of compounds that have to be identified against an environmentally derived olfactory background. This background, however, does not necessarily disturb the localization of a source. Rather, the contrary. Sex pheromones become more attractive to male moths when being presented against a relevant plant background. Here we asked whether such olfactory coaction also characterizes foraging cues. The tobacco hornworm Manduca sexta feeds on nectar from wild tobacco Nicotiana attenuata and sacred datura Datura wrightii flowers. We tested how leaf-derived volatile blends as a background affect the moths' approach to flower blends. We found coaction when a flower blend was presented against a conspecific leaf volatile background but not when the blend was presented against volatiles emitted by the other host plant or by a non-host plant. Hence, our results reveal a species-specific coaction between flower blend and leaf volatile background. The ability to integrate information from different odor sources on one plant might provide the moth with a fine-grained analysis of food site quality

A Single Sex Pheromone Receptor Determines Chemical Response Specificity of Sexual Behavior in the Silkmoth Bombyx mori

In insects and other animals, intraspecific communication between individuals of the opposite sex is mediated in part by chemical signals called sex pheromones. In most moth species, male moths rely heavily on species-specific sex pheromones emitted by female moths to identify and orient towards an appropriate mating partner among a large number of sympatric insect species. The silkmoth, Bombyx mori, utilizes the simplest possible pheromone system, in which a single pheromone component, (E, Z)-10,12-hexadecadienol (bombykol), is sufficient to elicit full sexual behavior. We have previously shown that the sex pheromone receptor BmOR1 mediates specific detection of bombykol in the antennae of male silkmoths. However, it is unclear whether the sex pheromone receptor is the minimally sufficient determination factor that triggers initiation of orientation behavior towards a potential mate. Using transgenic silkmoths expressing the sex pheromone receptor PxOR1 of the diamondback moth Plutella xylostella in BmOR1-expressing neurons, we show that the selectivity of the sex pheromone receptor determines the chemical response specificity of sexual behavior in the silkmoth. Bombykol receptor neurons expressing PxOR1 responded to its specific ligand, (Z)-11-hexadecenal (Z11-16:Ald), in a dose-dependent manner. Male moths expressing PxOR1 exhibited typical pheromone orientation behavior and copulation attempts in response to Z11-16:Ald and to females of P. xylostella. Transformation of the bombykol receptor neurons had no effect on their projections in the antennal lobe. These results indicate that activation of bombykol receptor neurons alone is sufficient to trigger full sexual behavior. Thus, a single gene defines behavioral selectivity in sex pheromone communication in the silkmoth. Our findings show that a single molecular determinant can not only function as a modulator of behavior but also as an all-or-nothing initiator of a complex species-specific behavioral sequence

Understanding plant-mediated interactions between two major maize pests of eastern Europe – from phytochemical patterns to management recommendations

Insect herbivores interact with each other via shared host plants. Understanding the consequences of plant-mediated interactions between different consumers is crucial to elucidate distribution patterns in nature and to understand how insect communities influence plant fitness and yield in agroecosystems. Here, we propose to study how root-infestation by the western corn rootworm Diabrotica virgifera influences oviposition and performance of the European corn borer Ostrinia nubilalis. These two insects are the major maize pests in Eastern Europe and have a massive impact on agricultural productivity in Serbia and Hungary. As D. virgifera only recently invaded the region, very little is known about its interaction with the native O. nubilalis. Studying how these two insects influence each other will not only fill a major gap of fundamental knowledge regarding the influence of root feeders on stem-borers, but will be indispensable to develop integrated pest management recommendations that enable farmers to optimize their cultural practices.By combining the expertise of the consortium partners, a series of experiments will be carried out to gain a detailed and agriculturally relevant picture on the interaction between D. virgifera on O. nubilalis. First, a field experiment in Serbia will be conducted to find out how root-attack changes the oviposition behavior of O. nubilalis. The results will be complemented with laboratory studies and volatile analyses with gas chromatography/mass spectrometry (GC/MS) and gas chromatography/ electorantennography (GC/EAD) in Hungary to identify the compounds that are responsible for the observed behavior. Second, a field experiment will be performed to investigate how D. virgifera influences O. nubilalis larval growth, performance and migration patterns. Again, the field data will be supplemented by a series of laboratory experiments in Switzerland involving high performance liquid chromatography (HPLC) metabolite profiling to pinpoint the phytochemical changes behind the field patterns. In a third experiment, the net effect of both herbivores on plant damage and yield will be measured in a realistic field setting in order to create detailed pest management recommendations for Serbian farmers

Pheromone titer and mating frequency of E-and Z-strains of the european corn borer, Ostrinia nubilalis : Fluctuation during scotophase and age dependence

Periodicity of pheromone titer in female moths, modulated by various factors (age, photoperiod, temperature), has been reported for a number species, however, comparative studies on pheromone strains of those species where pheromone polymorphism is known to occur has so far scarcely been studied.In this study, the rhythm and age dependence of calling behavior as well as of the titer of the respective main sex pheromone components, and timing and frequency of mating within E-and Z-strains of European corn borer (ECB), Ostrinia nubilalis Hbn. (Lepidoptera: Pyraustidae) were compared during scotophase, under laboratory conditions (18/6 hours photoregime, 26 °C).Very similar trends were fund in both strains in the diel fluctuation of both calling behavior and pheromone titer within the scotophase, as well as its age dependence, and also in timing and mating frequency. The titer of the respective main pheromone component gradually increased during the scotophase. Highest titers were found in freshly emerged females, however even 6-day-old females produced roughly half amounts. Freshly emerged females of both strains were ready to mate with males of their own strain, however, the percentage of matings were higher in 1–3-day-old age cohorts. Differences between strains was found in the total amount of the respective main pheromone components in the gland. The average amount of ( Z )11-tetradecenyl acetate extracted from the ovipositor of Z-strain females 10 min. before the end of the scotophase was 2.17 ng / female equivalent, whereas the corresponding value of ( E )11-tetradecenyl acetate for E-strain females was 8.25 ng / female equivalent. Moreover, E-strain females tended to start calling somewhat earlier, and the percentages of calling females was higher during the peak calling period than that of the Z-strain. Significance of these findings in characterizing the strains are discussed

Rheologische Untersuchung zur Messung und Standardisierung von Probenahrung sowie zur Bestimmung von Nahrungsrezepturen für die Ernährung der Dysphagie-Patienten

Aufgrund von rheologischer Messung (Viskosität, mPa.s) wurden diätetische Standards erarbeitet, die die Aspirationsgefahr mindern und das Bestimmen von Kalorien- und Flüssigkeitsgehalt der Nahrung ermöglichen.Es wurde zunächst eine Viskositätsreihe mit zunehmender Viskosität der Probenahrung bestimmt, indem Wasser mit im Handel erhältlichen Eindickungsmitteln zu zähflüssigem Wasser, zu Gelee, zu Pudding und zu Brei stufenweise eingedickt wurde. Zu der so erhaltenen Viskositätskurve wurden im zweiten Schritt Speisen des täglichen Bedarfs mit bekannter Rezeptur zugeordnet. Nun konnte bestimmt werden, welche Konsistenz/Viskosität der erfolgreich geschluckte Bolus hatte und welche Speise genau dieser Viskosität entspricht. Die Methode ermöglicht die Standardisierung des Probebolus sowie einiger Speisen, die in den Krankenhäusern oder zuhause dem Patienten ohne Gefahr angeboten werden können. Da der Flüssigkeitsgehalt und der Kaloriengehalt dieser Speisen bekannt sind, ist es möglich, zu beurteilen, ob die orale Ernährung ausreicht oder eine Ergänzung via Sonde notwendig ist