6,150 research outputs found
Everything You Know About the Bush Environmental Record is Wrong
Conventional wisdom says that George W. Bush has 'declared war on the environment.' Yet actual instances of Bush anti-environmental policies are few, while the new president has received no credit for significant actions to reduce air pollution. What's the political and media dynamic that makes everyone feel so sure that Bush is anti-environment?
Ferritin in the fungus Phycomyces
The iron-protein ferritin has been purified from mycelium, sporangiophores, and spores of the fungus Phycomyces blakesleeanus. It has a protein-to-iron ratio of 5, a sedimentation coefficient of 55S, a buoyant density in CsCl of 1.82 g/cm3, and the characteristic morphology of ferritin in the electron microscope. Apoferritin prepared from Phycomyces ferritin has a sedimentation coefficient of 18S and consists of subunits of molecular weight 25,000. In the cytoplasm of Phycomyces, ferritin is located on the surface of lipid droplets (0.5–2.0 µ in diameter) where it forms crystalline monolayers which are conspicuous in electron micrographs of sporangiophore thin-sections. Ferritin is found in all developmental stages of Phycomyces but is concentrated in spores. The level of ferritin iron is regulated by the iron level in the growth medium, a 50-fold increase occurring on iron-supplemented medium
Morphology of deoxyribonucleic acid extracted from cores of vaccinia virus
It has been shown recently that the outer layers of vaccinia virions can be removed selectively under mild conditions to yield a preparation that consists entirely of "cores" (K. B. Easterbrook, Ultrastruct. Res. 14:484, 1966). Since these cores can be very easily ruptured and dissolved, they would seem to offer advantages over complete virions as starting material for the extraction of unbroken genomes. This note describes results obtained in an investigation into the morphology of DNA isolated from vaccinia viral cores by further detergent treatment
A taxonomy of asymmetric requirements aspects
The early aspects community has received increasing attention among researchers and practitioners, and has grown a set of meaningful terminology and concepts in recent years, including the notion of requirements aspects. Aspects at the requirements level present stakeholder concerns that crosscut the problem domain, with the potential for a broad impact on questions of scoping, prioritization, and architectural design. Although many existing requirements engineering approaches advocate and advertise an integral support of early aspects analysis, one challenge is that the notion of a requirements aspect is not yet well established to efficaciously serve the community. Instead of defining the term once and for all in a normally arduous and unproductive conceptual unification stage, we present a preliminary taxonomy based on the literature survey to show the different features of an asymmetric requirements aspect. Existing approaches that handle requirements aspects are compared and classified according to the proposed taxonomy. In addition,we study crosscutting security requirements to exemplify the taxonomy's use, substantiate its value, and explore its future directions
African studies libraries: background to U.S. organization and initiatives and prospects for international cooperative projects : paper delivered at the German – North American resources project conference, 5 – 7 October 2006 ; [Vortrag am 6th Frankfurt scientific symposium, GNARP und wie sie die Welt sieht: Aussichten transatlantischer Partnerschaft im digitalen Zeitalter: 5.10.2006 - 7.10.2006]
The paper will provide a brief background to the history of the organization and cooperative efforts of African studies librarians in the United States including their efforts at international cooperation. Particular emphasis will be placed on the current opportunities for improved cooperation as digitization activities increase. Examples will include the DISA and Aluka initiatives and well as the Timbuktu manuscript digitization project at the Center for Research Libraries. Particular emphasis will placed on the possibilities for German-North American cooperation in the area of digital projects of historical photographs given the extensive collections held at Northwestern and Frankfurt
Healthy homes, healthier lives: health improvements through housing related initiatives and services
Advance and Retreat of Cordilleran Ice Sheets in Washington, U.S.A.
Cordilleran Ice Sheet glaciations show characteristic patterns of advance and retreat, consisting of (1) advance out outwash, (2) glacial scouring, (3) deposition of till, (4) deposition of recessional outwash south of Seattle in the southern Puget Lowland, glaciomarine drift in the northern lowland, and eskers, kames, and small moraines on the Columbia Plateau. Radiocarbon dates show that the Puget and Juan de Fuca lobes advanced and retreated synchronously. The Puget lobe backwasted to Seattle by 13.4-14 ka yrs BP, where the thinning ice floated in seawater northward to Canada by 13 ka yrs BP depositing glaciomarine drift contemporaneously over 18,000 km2. Compelling evidence against the backwasting, calving, terminus model for the origin of the glaciomarine drift includes: 1) abundant 14C dates demonstrate simultaneous deposition of glaciomarine drift over the entire area; 2) stagnant-ice deposits closely related to glaciomarine drift are not consistent with an actively-calving, backwasting terminus; 3) irrefutable evidence for the nonmarine origin of Deming sand shows that Cordilleran ice was absent immediately prior to deposition of the overlying glaciomarine drift. The pattern of events in the northern Puget Lowland includes: 1) glacial loading under 1800 m of ice during the Vashon maximum; 2) rapid glacial thinning and floating of the ice deposited Kulshan glaciomarine drift 12-13 ka yrs BP; 3) emergence and deposition of fluvial Deming sand 11.5 ka yrs BP; 4) resubmer-gence and deposition of Bellingham glaciomarine drift up to -200 m, well beyond global eustatic sea level rise; 5) emergence 10.5-11.5 ka yrs BP and deposition of Sumas outwash on Bellingham glaciomarine drift; 6) Holocene eustatic sea level rise kept pace with isostatic rebound, thus, post-Sumas marine terraces are absent.Dans la Cordillère, les glaciations se sont produites selon des modes caractéristiques d'avancée et de recul : 1) dépôts fluvioglaciaires d'avancée; 2) poli glaciaire; 3) till; 4) dépôts fluvio-glaciaires de retrait au sud de Seattle, dans le sud des basses-terres de Puget, dépôts glacio-marins dans les basses-terres du nord, et eskers, terrasses fluvioglaciaires et petites moraines sur le plateau de Columbia. La datation au radiocarbone indique que les lobes de Puget et de Juan de Fuca ont avancé et reculé synchroniquement. Parmi les preuves qui nous contraignent à rejeter l'hypothèse selon laquelle un front en fusion, qui vêlait, serait à l'origine des dépôts glacio-marins, citons : 1) les nombreuses datations au radiocarbone qui révèlent la mise en place simultanée de dépôts glacio-marins sur tout le territoire; 2) les dépôts issus de la fusion de la glace stagnante, intimement associés aux dépôts glacio-marins; 3) les preuves irréfutables d'une origine autre que marine des sables de Deming qui révèlent que la Cordillère était libre de glace immédiatement avant la mise en place des dépôts glacio-marins. Dans le nord des basses-terres de Puget le déroulement des événements comprend les étapes suivantes : 1) au cours du maximum de Vashon, charge glaciaire sous 1800 m de glace; 2) 12-13 ka BP, amincissement rapide du glacier et dérive de la glace contribuant à la mise en place des dépôts glacio-marins de Kulshan; 3) vers 11 500 ans BP, emersion et dépôt des sables de Deming d'origine fluviale; 4) nouvelle submersion et mise en place des dépôts glacio-marins de Bellingham jusqu'à une hauteur d'environ 200 m, bien supérieure à l'élévation eustatique du niveau de la mer; 5) vers 10 500-11 500 ans BP, emersion et mise en place des dépôts fluvio-glaciaires de Sumas sur les dépôts glacio-marins de Bellingham; 6) à l'Holocène, élévation eustatique du niveau de la mer au même rythme que le relèvement isostatique.Die Vereisung der Kordilleren-Eisdecke zeigt charakteristische VorstoB- und Rùckzugsmuster, bestehend aus (1) glazialem SchwemmvorstoB, (2) glazialem Scheuern, (3) Ablagerung der Grundmoràne, (4) Ablagerung von Rùckzugsschwemm-Material sùdlich von Seattle im sûdlichen Puget-Lowland, glaziomarines Material im nôrdlichen Tiefland und Esker, Kames und kleine Morànen auf dem Columbia-Plateau. Radiokarbondaten zeigen, daf3 die Puget - und Juan de Fuca-Loben gleichzeitig vorstieBen und sich zurûckzogen. Gegen das rùcklàufige, kalbende Terminus-Modell fur den Ursprung des glaziomarinen Materials sprechen die folgenden Tatsachen in zwingender Weise: 1) zahlreiche '"C-Daten beweisen die gleichzeitige Ablagerung von glaziomarinem Material ùber das gesamte Gebiet; 2) Ablagerungen von stagnierendem Eis, die in enger Verbindung zu glaziomarinem Material stehen, stimmen nicht mit einem aktiv kalbenden rùcklàufigen Terminus ùberein; 3) unwiderlegbares Beweismaterial fur den nichtmarinen Ursprung des Sands von Deming zeigt, daB es kein Kordilleren-Eis gab unmittelbar vor der Ablagerung darùberliegen-den glaziomarinen Materials. Die Abfolge der Ereignisse im nôrdlichen Puget Lowland bein-haltet: 1) glaziale Fracht unter 1800 m Eis wàhrend des Vashon Maximums; 2) schnelles glaziales Ausdùnnen und treibendes Eis lagerte 12-13 ka Jahre v.u.Z. das glazioma-rine Material von Kulshan ab; 3) Auftauchen und Ablagerung von Deming-FluBsand -11.5ka Jahre v.u.Z.; 4) Wiederuntertauchen und Ablagerung von glaziomarinem Belligham-Material bis zu - 200 m, weit ùber die globale eustatische Meeresan-hebung hinaus; 5) Auftauchen - 10.5-11.5 ka Jahre v.u.Z. und Ablagerung von Sumas-Schwemm-Material auf dem glaziomarinen Bellingham-Material; 6) die eustatische Anhebung des Meeresspiegels im Holozàn hielt Schritt mit dem isostatischen Ruckprall
Bias in research
The aim of this article is to outline types of ‘bias’ across research designs, and consider strategies to minimise bias. Evidence-based nursing, defined as the “process by which evidence, nursing theory, and clinical expertise are critically evaluated and considered, in conjunction with patient involvement, to provide the delivery of optimum nursing care,”1 is central to the continued development of the nursing professional. Implementing evidence into practice requires nurses to critically evaluate research, in particular assessing the rigour in which methods were undertaken and factors that may have biased findings
Lead, zinc and copper mineralisation in basal Carboniferous sediments at Westwater, south Scotland
A zioneo f lead, zinc and copperm ineralisatioins developedo ver a minimum
I of 4 km of strikeo f basal Carboniferoucse mentstoneg roup sedimentsa nd
immediatelyu nderlyingB irrenswarkL avas atwestwater,n ear Laqholm in south
Scotland. Grades so far obtained from sparse rock exposures and from shallow
boreholes
a fissure
sulphides
are usuallyO .l-O.j%o f combinedm etals over 1-2 m of thickness,bu t
vein of higher grade and a relativelyt hick zone of disseminated
were also located. Galena, sphalerite,c halcopyritea ndbaryte
occur mainly in thin dolomitev eins but disseminationosf galenaa re also
presenti n sandstoneu nits. The mineralisatioins of low temperaturet ype
I
was emplaceda long northeasterlyt rendingn ormal faultsa nd cross faults
regardeda s late Carboniferouisn age.
and
Mineralisatiohna s been controlledb y faulting,r egionalf aciesv aziation
and local lithologicalv ariationa s well as by stratigraphipco sition. These
controlsa re applicablei n furthere xplorationo f Lower Carboniferourso cks in
both south and central Scotland. The heavy mineral fraction of stream sediment
is the optimums amplingt ype in reconnaissanceex plorationo f areas of calcareous .
rocks such as the Lower Carboniferouso f south Scotlanda nd basal till sampling
is the most effectivem ethod of follow-upe xplorationi n those areas where
glaciald epositsa re widespreada nd often thick
- …
