422 research outputs found
Flora, vegetation and avifauna in the Bövinghauser Bachtal between Bochum and Dortmund (North Rhine Wesphalia, Germany)
Das unter Naturschutz stehende Gebiet des Bövinghauser Bachtals (NSG Oberes Ălbachtal in Bochum, NSG Ălbachtal in Dortmund) wurde floristisch, vegetationskundlich und avifaunistisch untersucht. Insbesondere die Ergebnisse der botanischen Untersuchungen werden hier vorgestellt und zur Analyse herangezogen, um VerĂ€nderungen festzustellen, die sich seit ersten Untersuchungen Anfang der 1980er Jahre ergeben haben. Insgesamt wurden 437 Sippen an Höheren Pflanzen festgestellt, 366 davon wurden als dauerhaft ansĂ€ssige Arten gewertet. 19 Arten stehen in einer der Roten Listen, 5 Arten werden auf der Vorwarnliste Nordrhein-Westfalen gefĂŒhrt. Festgestellt wurde insbesondere ein RĂŒckgang oder sogar der Verlust von Arten, die nĂ€hrstoffarme und/oder eine niedrige Vegetation benötigen. Pflanzensoziologisch wurden die gebietstypischen und dominierenden Pflanzengesellschaften erfasst. FĂŒnf der gefundenen Pflanzengesellschaften stehen in einer Kategorie der Roten Liste. Zu den regional wichtigsten und auch fĂŒr die Tierwelt bedeutendsten Biotopen gehören die groĂflĂ€chig ausgebildeten Röhrichtgesellschaften im Haupttal des Bövinghauser Baches, die in Form des Scirpo-Phragmitetums sowie der GroĂseggenrieder des Caricetum gracilis und des Caricetum acutiformis landesweit gefĂ€hrdet sind. AuffĂ€llig ist die "Verbrennnesselung" der Gesellschaften, die sich insbesondere an WegrĂ€ndern und in den Feuchtgebieten bemerkbar macht. Hierauf weist auch das reichliche Auftreten von Gesellschaften hin, die aufgrund der Bevorzugung eutropher Standorte landesweit in Ausbreitung begriffen sind. Diese Befunde weisen auch auf die starke NĂ€hrstoffbelastung, insbesondere Stickstoffbelastung, des Gebiets hin. GrĂŒnde hierfĂŒr sind insbesondere der Eintrag durch die angrenzende Landwirtschaft sowie durch Hunde- und Pferdekot. Die Kartierung des Vogelbestands ergab insgesamt 70 Arten. Unter ihnen wurden 44 Brutvogelarten mit 230 Paaren festgestellt. Von den Vogelarten des Gebietes stehen insgesamt 22 auf der Roten Liste, davon 9 Brutvögel. Das Gebiet bietet durch seine Vielgestaltigkeit und hier insbesondere durch die groĂflĂ€chig ausgebildeten Feuchtgebiete einen in der nĂ€heren Umgebung einzigartigen Lebensraum fĂŒr viele seltene Brutvogelarten. So wurden im Untersuchungsjahr Bruten von Feldschwirl, Schwarzkehlchen, Rohrammer und TeichrohrsĂ€nger festgestellt. Insgesamt ist festzustellen, dass die Anzahl der Brutpaare besonders in den Röhricht- und Hochstaudenbereichen vor allem auf Grund der hĂ€ufigen Störungen durch SpaziergĂ€nger und freilaufende Hunde relativ niedrig bleibt. Auch fĂŒr die GewĂ€sserbrĂŒter bestehen derzeit keine ausreichenden Ruhezonen.A quantitative and qualitative assessment of flora, vegetation and avifauna was conducted in the nature reserves surrounding the Bövinghauser Bachtal (NSG âOberes Ălbachtalâ in Bochum, âNSG Ălbachtal in Dortmund, Westphalia). In 2007, a total of 437 vascular plants were found, where 366 species were classified as established while the others are ephemeral garden escapes or were planted within the area (e. g. forest trees). The assessment showed that 5 plant communities and 19 plant species are red-listed and even 5 species belong to the category âNear threatened in North Rhine Westphaliaâ. The results were compared to former studies of the early 1980âs. A substantial decrease or even loss of species of low and nutrient-poor vegetation types became evident. From an ecological point of view the most important vegetation types are a few artificial ponds and particularly the expanded reed areas in the main valley mostly composed with Phragmites australis. Threatened plant communities in these wetlands are Scirpo-Phragmitetum, Caricetum gracilis and Caricetum acutiformis. Striking was also the high amount of Stinging Nettle (Urtica dioica) particularly along the trails but also in the wetlands. The occurrence of Stinging Nettle and other nitrophilous plant communities is a clear indicator of eutrophication. These wetlands are also important habitats for rare breeding birds of the Ruhr-Area as Grasshopper warbler, Common stonechat, Reed bunting, Reed warbler and Water rail. A total of 70 bird species were recorded in the study area, 44 of them breeding birds with at least one detected nest. Altogether 230 nests were detected. Especially for wetlands this is a low number considering the size of the area and its diverse biotopes. This is most likely due to a high frequency of disturbance caused by recreational activities such as cycling and hiking, but also unleashed dogs. Recommendations are given in this study to minimize the mentioned issues and to facilitate a natureorientated development of this important biological reserve
Transport mechanisms during the high-temperature oxidation of ternary Îł/ÎłâČ Co-base model alloys
Over a decade ago, ÎłâČ-strengthened Co-base alloys were introduced as potential replacement for conventional Ni-base Superalloys. Insufficient resistance against high-temperature oxidation restricts the number of possible applications. The present study contributes to the understanding of elementary mechanisms such as material transport during extensive oxide scale formation on Îł/ÎłâČ Co-base alloys to explain their inferior oxidation behaviour. A clear dependency of the scale growth kinetics on W content and oxidation temperature is demonstrated by thermogravimetry and subsequent analysis of cross-sections. By means of electron backscattered diffraction (EBSD), the evolution of microstructures in the outer oxide layers were examined depending on the oxidation temperature. Sequential exposure of samples in 16O2- and 18O2-containing atmospheres proved counter-current material transport. The combination of focused ion beam (FIB) and secondary ion mass spectroscopy (SIMS) visualised the formation of new oxide phases mainly on the outer and inner interface of the oxide scale. An elaborate review of available transport paths for oxygen is given during the discussion of results. All experimental findings were combined to a coherent explanation of the inferior oxidation resistance of this relatively new class of high-temperature materials at temperatures above 800â°C
Free Antiretrovirals Must Not Be Restricted Only to Treatment-Naive Patients: Experience in Uganda suggests that restricting access is not the way forward
In some antiretroviral drug distribution programmes, free drugs are provided only, or preferentially, to patients who are treatment-naive. Colebunders and colleagues argue that such a restricted policy is highly problematic
The HIV-1 late domain-2 S40A polymorphism in antiretroviral (or ART)-exposed individuals influences protease inhibitor susceptibility.
BackgroundThe p6 region of the HIV-1 structural precursor polyprotein, Gag, contains two motifs, P7TAP11 and L35YPLXSL41, designated as late (L) domain-1 and -2, respectively. These motifs bind the ESCRT-I factor Tsg101 and the ESCRT adaptor Alix, respectively, and are critical for efficient budding of virus particles from the plasma membrane. L domain-2 is thought to be functionally redundant to PTAP. To identify possible other functions of L domain-2, we examined this motif in dominant viruses that emerged in a group of 14 women who had detectable levels of HIV-1 in both plasma and genital tract despite a history of current or previous antiretroviral therapy.ResultsRemarkably, variants possessing mutations or rare polymorphisms in the highly conserved L domain-2 were identified in seven of these women. A mutation in a conserved residue (S40A) that does not reduce Gag interaction with Alix and therefore did not reduce budding efficiency was further investigated. This mutation causes a simultaneous change in the Pol reading frame but exhibits little deficiency in Gag processing and virion maturation. Whether introduced into the HIV-1 NL4-3 strain genome or a model protease (PR) precursor, S40A reduced production of mature PR. This same mutation also led to high level detection of two extended forms of PR that were fairly stable compared to the WT in the presence of IDV at various concentrations; one of the extended forms was effective in trans processing even at micromolar IDV.ConclusionsOur results indicate that L domain-2, considered redundant in vitro, can undergo mutations in vivo that significantly alter PR function. These may contribute fitness benefits in both the absence and presence of PR inhibitor
Drug sensitivity profiling of 3D tumor tissue cultures in the pediatric precision oncology program INFORM
The international precision oncology program INFORM enrolls relapsed/refractory pediatric cancer patients for comprehensive molecular analysis. We report a two-year pilot study implementing ex vivo drug sensitivity profiling (DSP) using a library of 75-78 clinically relevant drugs. We included 132 viable tumor samples from 35 pediatric oncology centers in seven countries. DSP was conducted on multicellular fresh tumor tissue spheroid cultures in 384-well plates with an overall mean processing time of three weeks. In 89 cases (67%), sufficient viable tissue was received; 69 (78%) passed internal quality controls. The DSP results matched the identified molecular targets, including BRAF, ALK, MET, and TP53 status. Drug vulnerabilities were identified in 80% of cases lacking actionable (very) high-evidence molecular events, adding value to the molecular data. Striking parallels between clinical courses and the DSP results were observed in selected patients. Overall, DSP in clinical real-time is feasible in international multicenter precision oncology programs
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Post-postfeminism? New feminist visibilities in postfeminist times
This article contributes to debates about the value and utility of the notion of postfeminism for a seemingly ânewâ moment marked by a resurgence of interest in feminism in the media and among young women. The paper reviews current understandings of postfeminism and criticisms of the termâs failure to speak to or connect with contemporary feminism. It offers a defence of the continued importance of a critical notion of postfeminism, used as an analytical category to capture a distinctive contradictory-but-patterned sensibility intimately connected to neoliberalism. The paper raises questions about the meaning of the apparent new visibility of feminism and highlights the multiplicity of different feminisms currently circulating in mainstream media culture â which exist in tension with each other. I argue for the importance of being able to âthink togetherâ the rise of popular feminism alongside and in tandem with intensified misogyny. I further show how a postfeminist sensibility informs even those media productions that ostensibly celebrate the new feminism. Ultimately, the paper argues that claims that we have moved âbeyondâ postfeminism are (sadly) premature, and the notion still has much to offer feminist cultural critics
Drug sensitivity profiling of 3D tumor tissue cultures in the pediatric precision oncology program INFORM
The international precision oncology program INFORM enrolls relapsed/refractory pediatric cancer patients for comprehensive molecular analysis. We report a two-year pilot study implementing ex vivo drug sensitivity profiling (DSP) using a library of 75â78 clinically relevant drugs. We included 132 viable tumor samples from 35 pediatric oncology centers in seven countries. DSP was conducted on multicellular fresh tumor tissue spheroid cultures in 384-well plates with an overall mean processing time of three weeks. In 89 cases (67%), sufficient viable tissue was received; 69 (78%) passed internal quality controls. The DSP results matched the identified molecular targets, including BRAF, ALK, MET, and TP53 status. Drug vulnerabilities were identified in 80% of cases lacking actionable (very) high-evidence molecular events, adding value to the molecular data. Striking parallels between clinical courses and the DSP results were observed in selected patients. Overall, DSP in clinical real-time is feasible in international multicenter precision oncology programs
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