152 research outputs found
Science on the Rise in Developing Countries
The disparity in the scientific output between developed and developing counties is dramatic, but, as the Americas show, this grim picture is improvin
Retrospective Analysis of Serotype Switching of Vibrio cholerae O1 in a Cholera Endemic Region Shows It Is a Non-random Process.
Genomic data generated from clinical Vibrio cholerae O1 isolates collected over a five year period in an area of Kolkata, India with seasonal cholera outbreaks allowed a detailed genetic analysis of serotype switching that occurred from Ogawa to Inaba and back to Ogawa. The change from Ogawa to Inaba resulted from mutational disruption of the methyltransferase encoded by the wbeT gene. Re-emergence of the Ogawa serotype was found to result either from expansion of an already existing Ogawa clade or reversion of the mutation in an Inaba clade. Our data suggests that such transitions are not random events but rather driven by as yet unidentified selection mechanisms based on differences in the structure of the O1 antigen or in the serotype-determining wbeT gene
Bedömning av status för nationellt förvaltade fisk- och skaldjursbestÄnd
Institutionen för akvatiska resurser vid Sveriges lantbruksuniversitet (SLU Aqua) presenterar Ärligen statusbedömningar för nationellt förvaltade fisk- och skaldjursbestÄnd i svenska vatten pÄ webbportalen www.fiskbarometern.se. Fiskbarometerns statusbedömningar av fisk- och skaldjursbestÄnd, utgör ett viktigt underlag för hÄllbart nyttjande, bevarandeÄtgÀrder och uppföljning inom fisk-, vatten- och miljöförvaltningen. I denna rapport redovisas metodiken för dessa statusbedömningar. Metodiken bidrar till en standardiserad och kvalitetssÀkrad bedömningsprocess som Àr transparent och som vilar pÄ vetenskaplig grund. För de flesta bestÄnd i Fiskbarometern baseras bedömningen pÄ indikatorer indelade i dödlighet, biomassa/abundans och storleks-/Äldersstruktur, vilka motsvarar Havsmiljödirektivets tre kriterier för bedömning av kommersiellt nyttjade bestÄnd (2008/56/EC). Baserat pÄ sammanvÀgningen av de tre kriterierna ges respektive bestÄnd sedan en av fem möjliga statusbedömningar:⹠kan ej bedömas ⹠mycket sannolikt inte inom biologiskt sÀkra grÀnser ⹠sannolikt inte inom biologiskt sÀkra grÀnser ⹠sannolikt inom biologiskt sÀkra grÀnser ⹠mycket sannolikt inom biologiskt sÀkra grÀnserFör nÄgra nationellt förvaltade bestÄnd finns eller pÄgÄr arbete med att utveckla analytiska bestÄndsmodeller. I den hÀr rapporten presenteras riktlinjer för kvalitetssÀkring och tillÀmpning av dem översiktligt, men den vetenskapliga granskningen av sÄdana modeller hanteras separat inom en process som kallas riktmÀrkning, vilken inte beskrivs i denna rapport. Utfall frÄn dessa modeller översÀtts till samma statuskategorier som för de indikatorbaserade bedömningarna
Short-term prediction and harvest control rules for Baltic cod (Gadus morhua): A generic method to include state of the art knowledge on environmental uncertainty and its consequences â would it make a difference for advice?
Vital processes relevant for exploited stocks, for example growth, predation and recruitment are closely related to the environmental conditions. Here, we present a generic method to include state of the art knowledge on environmental impacts and environmental forecasting into short-term predictions and the formulation of environment-based harvest control rules for exploited stocks. The method consists of three elements: First, the linkage between environmental parameters and stock dynamics, second the short-term prediction of both environment and stock dynamics, and third the scaling of otherwise constant reference values for fishing mortality in accordance with the environmental situation. The method is exemplified for Eastern Baltic cod. Recruitment is treated as dependent on oxygen conditions, and the formulation of the proposed fishing intensity is accounting for the actual oxygen conditions and predicted conditions for the year following the assessment year. Finally, the resulting advice is compared to advice that has been given not accounting for the oxygen conditions
Identification of Proteins Targeted by the Thioredoxin Superfamily in Plasmodium falciparum
The malarial parasite Plasmodium falciparum possesses a functional thioredoxin and glutathione system comprising the dithiol-containing redox proteins thioredoxin (Trx) and glutaredoxin (Grx), as well as plasmoredoxin (Plrx), which is exclusively found in Plasmodium species. All three proteins belong to the thioredoxin superfamily and share a conserved Cys-X-X-Cys motif at the active site. Only a few of their target proteins, which are likely to be involved in redox reactions, are currently known. The aim of the present study was to extend our knowledge of the Trx-, Grx-, and Plrx-interactome in Plasmodium. Based on the reaction mechanism, we generated active site mutants of Trx and Grx lacking the resolving cysteine residue. These mutants were bound to affinity columns to trap target proteins from P. falciparum cell extracts after formation of intermolecular disulfide bonds. Covalently linked proteins were eluted with dithiothreitol and analyzed by mass spectrometry. For Trx and Grx, we were able to isolate 17 putatively redox-regulated proteins each. Furthermore, the approach was successfully established for Plrx, leading to the identification of 21 potential target proteins. In addition to confirming known interaction partners, we captured potential target proteins involved in various processes including protein biosynthesis, energy metabolism, and signal transduction. The identification of three enzymes involved in S-adenosylmethionine (SAM) metabolism furthermore suggests that redox control is required to balance the metabolic fluxes of SAM between methyl-group transfer reactions and polyamine synthesis. To substantiate our data, the binding of the redoxins to S-adenosyl-L-homocysteine hydrolase and ornithine aminotransferase (OAT) were verified using BIAcore surface plasmon resonance. In enzymatic assays, Trx was furthermore shown to enhance the activity of OAT. Our approach led to the discovery of several putatively redox-regulated proteins, thereby contributing to our understanding of the redox interactome in malarial parasites
Molecular Analysis of ATP-sensitive K Channel Gating and Implications for Channel Inhibition by ATP
Competition and substitution between public transport modes
The management and understanding of modal split between public transport (PT) modes is of interest for numerous reasons. It may, for example, be desirable to stimulate passengers to switch from crowded buses and over to higher capacity rail. This requires a good understanding of drivers of transit modal substitution.
The evidence put forward in this paper is based on more than 150 empirically estimated cross elasticities between PT modes from over 20 sources collected from Australia, Europe and USA. These sources include scientifically published evidence as well as grey literature.
This evidence is coded into a database from which our paper presents and analyses the available cross-PT-modal demand relations. We focus on evidence for how fares, travel time and service intervals on PT âmode Aâ affect the demand for PT âmode Bâ.
Despite generally low levels of substitution between PT modes, passengers are particularly sensitive to in-vehicle, access/egress and waiting time in choosing PT mode and less so for fare variations. In general, rail demand is less sensitive to changes in bus than bus demand is to changes in rail. We also find that peak-hour demand more markedly switches between PT modes than off-peak demand does
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