996 resultados para Nanogram Amounts
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"HWRIC RR-026."
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Title varies slightly.
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Library retains current seven years only.
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Report year for <1974/75>-1975/76 ends June 30.
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Includes bibliographical references (p. 64).
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Running title: Wealth, debt, and taxation.
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One of the main challenges of classifying clinical data is determining how to handle missing features. Most research favours imputing of missing values or neglecting records that include missing data, both of which can degrade accuracy when missing values exceed a certain level. In this research we propose a methodology to handle data sets with a large percentage of missing values and with high variability in which particular data are missing. Feature selection is effected by picking variables sequentially in order of maximum correlation with the dependent variable and minimum correlation with variables already selected. Classification models are generated individually for each test case based on its particular feature set and the matching data values available in the training population. The method was applied to real patients' anonymous mental-health data where the task was to predict the suicide risk judgement clinicians would give for each patient's data, with eleven possible outcome classes: zero to ten, representing no risk to maximum risk. The results compare favourably with alternative methods and have the advantage of ensuring explanations of risk are based only on the data given, not imputed data. This is important for clinical decision support systems using human expertise for modelling and explaining predictions.
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Sokoldalú nemzetközi megállapodások és programok foglalkoznak a hulladékok keletkezésének és az országhatárokon átterjedő hatásainak problémájával, a nemzetközi együttműködést szükségessé tevő megoldásokkal. A leginkább átfogó megközelítést a probléma hajtóerőinek szentelt globális programok tartalmazzák, de a fenntarthatóság alapelveire támaszkodó termelési eljárásokra és fogyasztási szokásokra, a zöld gazdaságra való áttérést szorgalmazó dokumentumok nem tartalmaznak számon kérhető kötelezettségeket. A konkrétabb hulladékkeletkezési és hatásterjedési ügyekben – mindenekelőtt a veszélyes hulladékok és a nemzeti fennhatóság alá nem tartozó területekre eljutó vagy ott keletkező hulladékok esetében – jóval konkrétabb nemzetközi megállapodások és programok léteznek. Ezek szabályozási, szakpolitikai, technológiai célokat, feladatokat határoznak meg az országok és az érintett ágazati szereplők szintjén is. Egyes problémák kapcsán és egyes térségekben a hulladékgazdálkodás jelentős eredményeket tud felmutatni, de általában véve a nemzetközi megállapodások hatékony végrehajtásával komoly gondok vannak. Továbbá a meglévő nemzetközi eszközök összességükben még teljes körű végrehajtásuk esetén sem lennének képesek ellensúlyozni a hulladékprobléma globális szintű növekedését. Következésképpen további erőfeszítésekre van szükség – minden kormány, érintett nem-kormányzati szervezet és az ágazatok részéről – különösen a megelőzés vonatkozásában. ____ Various multilateral agreements and programmes deal with the problems of waste generation and its transboundary impacts, and those solutions, which necessitate international co-operation. Those global programmes include the most comprehensive approach, which are dedicated to the drivers of these problems, however, these documents promoting the transition to sustainable production and consumption, or to the green economy do not consist of binding commitments. In case of more concrete issues of waste generation and transboundary impacts there are much more concrete international agreements and programmes, especially, for the hazardous waste streams and the waste transmitted to and/or generated in areas outside national jurisdiction. These determine regulatory, policy, technological goals and tasks for the participating countries and the relevant sectors. Significant progress is demonstrated for some specific problems and in certain regions, but in general, there are serious concerns about the efficient implementation of the international agreements in their entirety. Moreover, even if those were fully accomplished, the existing set of the international instruments would be unable to counterweigh the global increase of the waste problem. Consequently, further efforts are needed by all countries, the relevant non-governmental organisations and sectors, primarily in order to prevent the further global escalation of the problem.
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Fire debris evidence is submitted to crime laboratories to determine if an ignitable liquid (IL) accelerant was used to commit arson. An ignitable liquid residue (ILR) may be difficult to analyze due to interferences, complex matrices, degradation, and low concentrations of analytes. Debris from an explosion and pre-detonated explosive compounds are not trivial to detect and identify due to sampling difficulties, complex matrices, and extremely low amounts (nanogram) of material present. The focus of this research is improving the sampling and detection of ILR and explosives through enhanced sensitivity, selectivity, and field portable instrumentation. Solid Phase MicroExtraction (SPME) enhanced the extraction of ILR by two orders of magnitude over conventional activated charcoal strip (ACS) extraction. Gas chromatography tandem mass spectrometry (GC/MS/MS) improved sensitivity of ILR by one order of magnitude and explosives by two orders of magnitude compared to gas chromatography mass spectrometry (GC/MS). Improvements in sensitivity were attributed to enhanced selectivity. An interface joining SPME to ion mobility spectrometry (IMS) has been constructed and evaluated to improve field detection of hidden explosives. The SPME-IMS interface improved the detection of volatile and semi-volatile explosive compounds and successfully adapted the IMS from a particle sampler into a vapor sampler. ^