Doing Gender Im Technisch-Naturwissen-Schaftlichen Bereich

Für die Lösung des Nachwuchsproblems in den Technikwissenschaften spielt die Gewinnung von Frauen eine zentrale Rolle. Die in der Expertise dargestellten Befunde verdeutlichen dreierlei: (1) In den Natur- und Technikwissenschaften "verliert" man Frauen sehr früh im Lebensverlauf. (2) Wie beim Durchlauf eines Trichters (leaking pipeline) verringert sich mit jeder Bildungs- und Karrierestufe die Anzahl von Frauen in diesen Fächern und Berufen. (3) Die Erhöhung des Interesses für Technikwissenschaften von Mädchen und Frauen ist nicht nur "ein Problem" für das Bildungssystem, sondern ganz wesentlich auch des Arbeitsmarktes. Die Befunde der Expertise zeigen, dass es unbedingt notwendig ist, jungen Frauen, die in technischen Berufen gut ausgebildet sind, eine höhere Chance als bisher zu geben, (a) ihren Beruf aus dem Bereich Mathematik, Informatik, Naturwissenschaften, Technik (im Folgenden kurz: MINT) auszuüben und (b) dies auch mit den gleichen Gratifikationen wie Männer. Diese Herausforderung muss - und zwar unabhängig von der Nachfrage nach neuem Personal in technischen Berufen - schnell gemeistert werden, wenn Wirtschaft und Politik ein ernst gemeintes Interesse an "Frauen in MINT-Berufen" besitzen

THE WHOOPING CRANE CROSS-FOSTERING EXPERIMENT: THE ROLE OF ANIMAL DAMAGE CONTROL

Predator losses of endangered species in reintroduction programs are unacceptable because of the scarcity of the species and the major commitment of staff time and funds. When the whooping crane (Grus americana) cross-fostering experiment (experiment) at Grays Lake National Wildlife Refuge (Grays Lake), Idaho was proposed in 1972, animal damage control (ADC) was considered unnecessary. Sandhill crane (G. canadensis tabida) nest success was high and coyotes (Canis latrans) and red foxes (Vulpes Vulpes) were uncommon. Canids increased by the mid-1970\u27s destroying whooping crane eggs and chicks. An ADC program initiated in 1976 has evolved into a major part of the experiment. The ADC program is costly and complex, requiring several permits and coordination among 5 state and federal agencies and 20+ private landowners. Current ADC effort uses several control methods and annually entails 40± hrs of helicopter time, 900± hrs of staff time and over 9600 km of vehicle use. Between 1975-84, 14 eggs and 23 to 58 flightless young whoopers were lost to predators, primarily coyotes. From 1976-84, 633 predators were removed from the control area; 72% were canids. The ADC program appears to have reduced predation on whooping crane eggs and chicks. Our experience at Grays Lake indicates that endangered species introduction programs should include ADC evaluations in preliminary planning processes

An Experimental Investigation in the Performance of Water-Filled Silicon Microheat Pipe Arrays

This study details the fabrication and measurements of a water-filled 5 mm wide by 10 mm long silicon microheat pipe (MHP) array consisting of 22–100 μm square channels. This study is unique in that many experimental results reported in open literature are for single channel microheat pipes. The number of channels in the array and the fluid charge used here were optimized under a separate study. A number of experiments were carried out on the specimen MHPs to determine their effective thermal conductivity and comparisons were made with previous results found in literature. The testing methodology was designed to remove systematic biases and the array thermal performance measurements are reported in terms of a silicon equivalence by identically measuring an uncharged empty silicon array as a baseline measurement. Two separate water-filled specimens were made, independently tested, and are reported to have thermal conductivities of 261 W/m K and 324 W/m K, representing a silicon equivalence of 1.8 and 2.2, respectively. All testing was performed in a horizontal orientation.</jats:p

Structure of UDP-N-acetylglucosamine enolpyruvyl transferase, an enzyme essential for the synthesis of bacterial peptidoglycan, complexed with substrate UDP-N-acetylglucosamine and the drug fosfomycin

AbstractBackground UDP-N-acetylglucosamine enolpyruvyl transferase (MurA), catalyses the first committed step of bacterial cell wall biosynthesis and is a target for the antibiotic fosfomycin. The only other known enolpyruvyl transferase is 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase, an enzyme involved in the shikimic acid pathway and the target for the herbicide glyphosate. Inhibitors of enolypyruvyl transferases are of biotechnological interest as MurA and EPSP synthase are found exclusively in plants and microbes.Results The crystal structure of Escherichia coli MurA complexed with UDP-N-acetylglucosamine (UDP-GlcNAc) and fosfomycin has been determined at 1.8 å resolution. The structure consists of two domains with the active site located between them. The domains have a very similar secondary structure, and the overall protein architecture is similar to that of EPSP synthase. The fosfomycin molecule is covalently bound to the cysteine residue Cys115, whereas UDP-GlcNAc makes several hydrogen-bonding interactions with residues from both domains.Conclusions The present structure reveals the mode of binding of the natural substrate UDP-GlcNAc and of the drug fosfomycin, and provides information on the residues involved in catalysis. These results should aid the design of inhibitors which would interfere with enzyme-catalyzed reactions in the early stage of the bacterial cell wall biosynthesis. Furthermore, the crystal structure of MurA provides a model for predicting active-site residues in EPSP synthase that may be involved in catalysis and substrate binding