Analysis of turbofan engine performance deterioration and proposed follow-on tests

Data and engine parts on in-service JT3D and JT8D engines were analyzed and documented relative to engine deterioration. It is concluded that the fan-compressor system of these engines contributes to the long term engine deterioration. An engine test and instrumentation plan was formulated for a proposed follow-on program. The goal of this program is to verify the above conclusion and to attempt to identify more precisely which components of the fan-compressor system are at fault

Antiprädationsverhalten von Weißwangengänsen auf Kolguyev und Svalbard

Auch in den arktischen Brutgebieten sind Wildgänse und ihre Brut durch Fressfeinde wie den Eisfuchs (Alopex lagopus) oder die Eismöwe (Larus hyperboreus) gefährdet. In diesem Bericht wird am Beispiel von Weißwangengänsen (Branta leucopsis) das Verhalten der Vermeidung von Prädation auf Svalbard mit dem der auf Kolguyev brütenden Artgenossen untersucht. Die Unterschiede und Gemeinsamkeiten werden diskutiert.On the breeding grounds geese and their broods are threatened by predators like polar foxes (Alopex lagopus) or Glacous Gulls (Larus hyperboreus). In this review we compare antipredation behaviour of breeding and broad rearing Barnacle Geese (Branta leucopsis) on Svalbard and Kolguev. Similarities and differences are presented and discussed

Comparison of anthelmintic and anti-bacterial agents fed weanling pigs reared on pasture

Bright Future? is known as Swine Day, 1977Forty-eight Yorkshire pigs averaging 35 lbs. were used to compare their performance under these feeding sequences: (A) mecadox plus banminth, received until weighing 75 lbs., followed by terrarnyci n to 125 lbs.; (B) worming with tramisol initially and feeding ASP-250 until weighing 125 lbs. To market weight, pigs in both treatment groups were fed a nonmedicated finisher diet. Rate of gain was similar for both treatments; the sequence A pigs, however, required 6% fewer lbs. of feed per pound of gain. Pigs fed banminth had, after 35 days, no ascarid scars in their livers and no ascarids in their intestines. Pigs wormed initially with tramisol had livers with 40 to 50 ascarid scars (both diaphragmatically and viscerally), and one pig had nine ascarids in his intestine. For pigs slaughtered at 125 lbs. and market weight, we observed fewer liver scars and intestinal ascarids in those wormed with banminth than with tramisol

Rabbit pasteurellosis: Respiratory and renal pathology of control and immunized rabbits after challenge with Pasteurella multocida

Gross and microscopic lesions of pasteurellosis were studied in control and immunized pasteurella-free rabbits after challenge with virulent Pasteurella multocida. Pathologic responses were compared in rabbits immunized intravenously or mucosally with P. multocidaor with J5, a cross protective core LPS mutant of E. coli Al1 rabbits were challenged conjunctivally with approximately 2xLD,, of P. multocida. Rabbits were necropsied and examined for histopathology of the respiratory tract and kidneys. Lung lesions varied in severity depending on the duration of the disease, the route of vaccination, and the vaccine used. The most severe lung lesions occurred in rabbits vaccinated intravenously with P. multocida and challenged with the same strain. Some of these rabbits had purulent bronchopneumonia and pleuropneumonia. Lung lesions were absent or less severe in rabbits vaccinated by a mucosal (aerosol, conjunctival) roiite and in unvaccinated controls. In these animals there was no bronchopneumonia or pleuropneumonia, and bronchiolitis, if present, was less severe. Kidney lesions were found only in rabbits vaccinated intravenously. There was an interstitial nephritis. some collagen deposition. mononuclear cell infiltration, and a loss of tubular architecture in the cortex. Some glomeruli were affected. These results indicate that intravenous immunization contributes to the formation of lesions whereas mucosal immunization prevented lesion formation to some degree

A periodic Markov model to formalize animal migration on a network

Regular, long-distance migrations of thousands of animal species have consequences for the ecosystems that they visit, modifying trophic interactions and transporting many non-pathogenic and pathogenic organisms. The spatial structure and dynamic properties of animal migrations and population flyways largely determine those trophic and transport effects, but are yet poorly studied. As a basis, we propose a periodic Markov model on the spatial migration network of breeding, stopover and wintering sites to formally describe the process of animal migration on the population level. From seasonally changing transition rates we derived stable, seasonal densities of animals at the network nodes. We parametrized the model with high-quality GPS and satellite telemetry tracks of white storks (Ciconia ciconia) and greater white-fronted geese (Anser a. albifrons). Topological and network flow properties of the two derived networks conform to migration properties like seasonally changing connectivity and shared, directed movement. Thus, the model realistically describes the migration movement of complete populations and can become an important tool to study the effects of climate and habitat change and pathogen spread on migratory animals. Furthermore, the property of periodically changing transition rates makes it a new type of complex model and we need to understand its dynamic properties.publishe

Data from: Goose parents lead migration V

Many migratory animals travel in large social groups. Large, avian migrants that fly in V‐formations were proposed do so for energy saving by the use of up‐wash by following individuals and regularly change leadership. As groups have been rather homogeneous in previous work, we aimed to explore leadership and its flight mechanics consequences in an extremely heterogeneous case of social migration, namely in spring migration of goose families. In families the experience of group members differs strongly and inclusive fitness may be important. We successfully collected overlapping spring migration tracking data of a complete family of greater white‐fronted geese (Anser a. albifrons) and extracted leadership, flapping frequency and wind conditions in flight. Our data revealed V‐formations where one parent was flying in front at all times. Although the father led the family group most of the time, he did not flap at higher frequency while doing so. In contrast, the mother flapped faster when leading, possibly because she experienced less supportive wind conditions than when the father led. We argue that in heterogeneous, social groups leadership might be fixed and not costly if supportive environmental conditions like wind can be used

Zeitliches und räumliches Auftreten rastender Goldregenpfeifer Pluvialis apricaria im Ems Dollart-Raum (Landkreis Leer, westliches Niedersachsen).

The coastal marshes around the River Ems and the Dollard Bay in NW Germany are a core stopover site for migratory and wintering European Golden Plovers. Numbers, spatial distribution, phenology and habitat selection were studied in a 415 km2 agricultural area (30% SPA), mainly constisting of meadows and arable fields. Weekly counts were carried out from mid October to mid April from 1996/97 to 2008/09. All flocks were plotted on a map to allow a detailed analysis of spatial distribution and habitat selection. Highest numbers of Golden Plovers were usually seen during autumn migration (notably November), with up to 41,000 individuals in autumn 2007. Moreover, there was a significant increase in maximum numbers in autumn from 1996/97 onwards, mainly due to a delayed departure in late autumn, as a result of mild weather. Wintering numbers were small but increased significantly over the same period, probably as a result of the prolonged series of mild winters. Numbers in spring were generally lower than in autumn and did not show a significant trend. During the investigations, about half of the study area was used by Golden Plovers. Highest numbers were found in the lowest parts of the area that consist of wet meadows. Arable fields behind the seawall of the Dollard Bay were only irregularly used, whilst peat-soil areas in the southern part of the study area were not visited at all. A habitat selection analysis using Jacobs’ Index revealed that in all parts of the year meadows were the preferred habitat. According to our observations this mainly reflects feeding birds. Only in spring, river forelands and salt marshes were additionally preferred, also implicating a more coastal distribution, as seen at other sites. Arable fields within the study area (stubble fields, autumn-sown cereals, harvest remains) were not part of preferred habitat at all.

Intercellular wiring enables electron transfer between methanotrophic archaea and bacteria

The anaerobic oxidation of methane (AOM) with sulfate controls the emission of the greenhouse gas methane from the ocean floor1, 2. In marine sediments, AOM is performed by dual-species consortia of anaerobic methanotrophic archaea (ANME) and sulfate-reducing bacteria (SRB) inhabiting the methane–sulfate transition zone3, 4, 5. The biochemical pathways and biological adaptations enabling this globally relevant process are not fully understood. Here we study the syntrophic interaction in thermophilic AOM (TAOM) between ANME-1 archaea and their consortium partner SRB HotSeep-1 (ref. 6) at 60 °C to test the hypothesis of a direct interspecies exchange of electrons7, 8. The activity of TAOM consortia was compared to the first ANME-free culture of an AOM partner bacterium that grows using hydrogen as the sole electron donor. The thermophilic ANME-1 do not produce sufficient hydrogen to sustain the observed growth of the HotSeep-1 partner. Enhancing the growth of the HotSeep-1 partner by hydrogen addition represses methane oxidation and the metabolic activity of ANME-1. Further supporting the hypothesis of direct electron transfer between the partners, we observe that under TAOM conditions, both ANME and the HotSeep-1 bacteria overexpress genes for extracellular cytochrome production and form cell-to-cell connections that resemble the nanowire structures responsible for interspecies electron transfer between syntrophic consortia of Geobacter9, 10. HotSeep-1 highly expresses genes for pili production only during consortial growth using methane, and the nanowire-like structures are absent in HotSeep-1 cells isolated with hydrogen. These observations suggest that direct electron transfer is a principal mechanism in TAOM, which may also explain the enigmatic functioning and specificity of other methanotrophic ANME–SRB consortia

Bis(diisopropylphosphinomethyl)amine Nickel(II) and Nickel(0) Complexes: Coordination Chemistry, Reactivity, and Catalytic Decarbonylative C–H Arylation of Benzoxazole

The facile one-step synthesis of five new bis­(diisopropylphosphinomethyl)­amine ligands RN­(CH₂DIP)₂ (DIP = diisopropylphosphine, R = Me–, <i>i</i>Pr–, PhCH₂–, 2-ThCH₂–, and 2-FuCH₂−) based on the use of the air-stable phosphonium salt [DIP­(CH₂OH)₂]Cl is presented. The phosphonium salt cleanly reacts with primary amines to afford amine-bridged bisphosphine ligands with variable backbone substitution in good yields. These DIP ligands are useful model systems for their chiral bisphospholane analogues. The coordination chemistry of neutral nickel­(II) complexes [(RDIP)­NiCl₂], [(RDIP)­Ni­(CH₃)₂], [(<i>i</i>PrDIP)­Ni­(Cl)­CH₂Si­(CH₃)₃], and [(RDIP)­Ni­(CH₂Ph)₂], as well as coordinatively unsaturated cationic nickel­(II) complexes [(RDIP)­Ni­(THF)­CH₃]⁺BArF^– and [(RDIP)­NiCH₂Ph]⁺BArF^–, has been studied by spectroscopic and X-ray diffraction methods. The cationic methyl complexes reacted cleanly with 2-butyne and 1,1-dimethylallene, yielding allylic complexes [(RDIP)­Ni­(pmcb)]⁺BArF^– and [(RDIP)­Ni­(tma)]⁺BArF^–, respectively (pmcb: η³-1,2,3,4,4-pentamethylcyclobutenyl; tma: η³-2,3,3-trimethylallyl). Nickel(0) complexes [(BzDIP)­Ni­(<i>trans</i>-stilbene)] and [(RDIP)­Ni­(C₂H₄)] were synthesized in one step from the corresponding dichloro complexes and have been fully characterized and analyzed by X-ray diffraction methods. [(MeDIP)­Ni­(C₂H₄)] reacted with phenyl-2-thiophenecarboxylate, yielding [(MeDIP)­Ni­(OPh)­(2-Th)] and [(MeDIP)­Ni­(CO)₂] in a 2:1 ratio. Both complexes were also synthesized via alternative routes. The phenolato-thienyl complex represents an intermediate in the catalytic cycle of a recently reported decarbonylative arylation of azoles. Complexes [(RDIP)­Ni­(C₂H₄)] were shown to be active catalysts for this reaction