natgillin/translations-raw huggingface dataset:
Hvis variansen er ekstremt heterogen og ikke kan korrigeres ved transformation, må analyse med step-down Jonkheere trend test overvejes.
For each treatment group and control group, calculate a mean value for growth rate along with variance estimates.
Supplerende vejledning for bestemmelse af NOEC er givet i (11).
Calculate the average specific growth rate over the entire test duration (normally days 0-3), using the nominally inoculated biomass as the starting value rather than a measured starting value, because in this way greater precision is normally obtained.
Den senere tids videnskabelige udvikling har ført til en anbefaling om, at NOEC-begrebet afskaffes og erstattes med regressionsbaserede punktestimater ECx.
If the equipment used for biomass measurement allows sufficiently precise determination of the low inoculum biomass (e.g. flow cytometer) then the measured initial biomass concentration can be used.
Der er ikke fastlagt en passende værdi for x til denne algetest.
Assess also the section-by-section growth rate, calculated as the specific growth rates for each day during the course of the test (days 0-1, 1-2 and 2-3) and examine whether the control growth rate remains constant (see validity criteria, paragraph 11).
Et område på 10 til 20 % synes at være passende (afhængigt af den valgte responsvariabel), og det må foretrækkes at rapportere både EC10 og EC20.
A significantly lower specific growth rate on day one than the total average specific growth rate may indicate a lag phase.
Vækststimulation
While a lag phase can be minimised and practically eliminated in control cultures by proper propagation of the pre-culture, a lag phase in exposed cultures may indicate recovery after initial toxic stress or reduced exposure due to loss of test chemical (including sorption onto the algal biomass) after initial exposure.
Ved lave koncentrationer ses undertiden vækststimulation (negativ hæmning).
Hence the section-by-section growth rate may be assessed in order to evaluate effects of the test chemical occurring during the exposure period.
Dette kan enten skyldes hormese (»toksisk stimulation«), eller at der er tilsat stimulerende vækstfaktorer sammen med testmaterialet til det anvendte minimalsubstrat.
Substantial differences between the section-by-section growth rate and the average growth rate indicate deviation from constant exponential growth and that close examination of the growth curves is warranted.
Bemærk, at tilsætning af uorganiske næringsstoffer ikke skulle have nogen direkte virkning, da testmediet skal indeholde overskud af næringsstoffer under hele testen.
Calculate the percent inhibition of growth rate for each treatment replicate from equation [2]:
Sædvanligvis kan der ses bort fra lavdosisstimulation i EC50-beregninger, medmindre den er ekstrem.
%I r
Er den ekstrem, eller skal der beregnes en ECx-værdi for en lav x-værdi, kan særlige procedurer dog være nødvendige.
percent inhibition in average specific growth rate;
Om muligt bør det undgås at lade stimulerende responsværdier udgå af dataanalysen, og kan den forhåndenværende kurvetilpasningssoftware ikke acceptere en lav grad af stimulation, kan der anvendes lineær interpolation med bootstrapping.
mean value for average specific growth rate (μ) in the control group;
Hvis stimulationen er ekstrem, kan det overvejes at anvende en hormese-model (18).
average specific growth rate for the treatment replicate.
Ikke-toksisk væksthæmning
When solvents are used to prepare the test solutions, the solvent controls rather than the controls without solvents should be used in calculation of percent inhibition.
Lysabsorberende teststoffer kan nedsætte væksthastigheden, fordi de ved at skygge mindsker den tilgængelige lysmængde.
Yield is calculated as the biomass at the end of the test minus the starting biomass for each single vessel of controls and treatments.
Sådanne fysiske virkninger må adskilles fra toksiske virkninger ved ændring af testbetingelserne og skal rapporteres særskilt.
For each test concentration and control, calculate a mean value for yield along with variance estimates.
Vejledning findes i (2) og (3).
The percent inhibition in yield ( %Iy) may be calculated for each treatment replicate as follows:
TESTRAPPORT
%I y
fysisk tilstand og relevante fysisk-kemiske egenskaber, herunder vandopløselighed
value for yield for the treatment replicate.
kemiske identifikationsdata (f.eks. CAS-nr.), herunder renhed (urenheder).
Plotting concentration response curve
Testarter:
Plot the percentage of inhibition against the logarithm of the test chemical concentration and examine the plot closely, disregarding any such data point that was singled out as an outlier in the first phase.
stamme, leverandør eller kilde og anvendte dyrkningsbetingelser.
Fit a smooth line through the data points by eye or by computerised interpolation to get a first impression of the concentration-response relationship, and then proceed with a more detailed method, preferably a computerised statistical method.
Testbetingelser:
Depending on the intended usage of data;
startdato og varighed for testen
the quality (precision) and amount of data as well as the availability of data analysis tools, it may be decided (and sometimes well justified) to stop the data analysis at this stage and simply read the key figures EC50 and EC10 (and/or EC20) from the eye fitted curve (see also section below on stimulatory effects).
beskrivelse af testens design:
Valid reasons for not using a statistical method may include:
testbeholdere, kulturvolumen, biomassetæthed ved testens start
Data are not appropriate for computerised methods to produce any more reliable results than can be obtained by expert judgement — in such situations some computer programs may even fail to produce a reliable solution (iterations may not converge etc.)
substratets sammensætning
Stimulatory growth responses cannot be handled adequately using available computer programs (see below).
testkoncentrationer og replikater (f.eks. antal replikater, antal testkoncentrationer og den anvendte geometriske progression)
Statistical procedures
beskrivelse af fremstillingen af testopløsningerne, herunder brug af opløsningsmiddel osv.
The aim is to obtain a quantitative concentration-response relationship by regression analysis.
dyrkningsapparatur
It is possible to use a weighted linear regression after having performed a linearising transformation of the response data — for instance into probit or logit or Weibull units (8), but non-linear regression procedures are preferred techniques that better handle unavoidable data irregularities and deviations from smooth distributions.
lysintensitet og -kvalitet (kilde, homogenitet)
Approaching either zero or total inhibition, such irregularities may be magnified by the transformation, interfering with the analysis (8).
temperatur
It should be noted that standard methods of analysis using probit, logit, or Weibull transforms are intended for use on quantal (e.g. mortality or survival) data, and must be modified to accommodate growth or biomass data.
testede koncentrationer:
Specific procedures for determination of ECx values from continuous data can be found in (9) (10) and (11).
de nominelle testkoncentrationer og alle resultater af bestemmelser af testkemikaliekoncentrationen i testbeholderne.
The use of non-linear regression analysis is further detailed in Appendix 5.
Metodens genfindingsgrad og kvantificeringsgrænse i testmatrixen skal rapporteres
For each response variable to be analysed, use the concentration-response relationship to calculate point estimates of ECx values.
alle fravigelser af nærværende testmetode
When possible, the 95 % confidence limits for each estimate should be determined.
metode til bestemmelse af biomasse og påvisning af korrelation mellem den målte parameter og tørvægten.
Goodness of fit of the response data to the regression model should be assessed either graphically or statistically.
Resultater:
Regression analysis should be performed using individual replicate responses, not treatment group means.
pH-værdi ved testens start og slutning for alle behandlinger
If, however nonlinear curve fitting is difficult or fails because of too great scatter in the data, the problem may be circumvented by performing the regression on group means as a practical way of reducing the influence of suspected outliers.
biomasse for hver kolbe ved hvert målepunkt samt metode til måling af biomasse
Use of this option should be identified in the test report as a deviation from normal procedure because curve fits with individual replicates did not produce a good result.
vækstkurver (biomasse som funktion af tiden)
estimates and confidence limits may also be obtained using linear interpolation with bootstrapping (13), if available regression models/methods are unsuitable for the data.
beregnede responsvariable for hver behandlingsreplikat, med gennemsnitsværdier og variationskoefficient for replikaterne
For estimation of the LOEC and hence the NOEC, for effects of the test chemical on growth rate, it is necessary to compare treatment means using analysis of variance (ANOVA) techniques.
grafisk fremstilling af sammenhængen mellem koncentration og virkning
The mean for each concentration must then be compared with the control mean using an appropriate multiple comparison or trend test method.
estimater for toksiciteten for responsvariablene, f.eks. EC50, EC10, EC20 med tilhørende konfidensintervaller.
Dunnett's or Williams' test may be useful (12)(14)(15)(16)(17).
LOEC og NOEC (hvis disse er beregnet) og de statistiske metoder, der anvendt til at bestemme dem
It is necessary to assess whether the ANOVA assumption of homogeneity of variance holds.
hvis variansanalyse er anvendt, størrelsen af den virkning, det er muligt at påvise (f.eks. mindste signifikante forskel)
This assessment may be performed graphically or by a formal test (17).
enhver vækststimulation, der er fundet ved nogen behandling
Suitable tests are Levene's or Bartlett's.
eventuelle andre observerede virkninger, f.eks. morfologiske ændringer af algerne
Failure to meet the assumption of homogeneity of variances can sometimes be corrected by logarithmic transformation of the data.
diskussion af resultaterne, herunder den eventuelle betydning af fravigelser fra denne testmetode.
If heterogeneity of variance is extreme and cannot be corrected by transformation, analysis by methods such as step-down Jonkheere trend tests should be considered.
Tillæg 1
Additional guidance on determining the NOEC can be found in (11).
Definitioner
Recent scientific developments have led to a recommendation of abandoning the concept of NOEC and replacing it with regression based point estimates ECx.
Følgende definitioner og forkortelser anvendes i denne testmetode:
An appropriate value for x has not been established for this algal test.
Kemikalie betyder et stof eller en blanding.
A range of 10 to 20 % appears to be appropriate (depending on the response variable chosen), and preferably both the EC10 and EC20 should be reported.
Variationskoefficient er et dimensionsløst mål for variabiliteten af en parameter, defineret som forholdet mellem standardafvigelsen og middelværdien.
Growth stimulation
Den kan også angives i procent.
Growth stimulation (negative inhibition) at low concentrations is sometimes observed.
Middelværdien af variationskoefficienten for den gennemsnitlige specifikke væksthastighed i kontrolkulturreplikater beregnes som følger:
This can result from either hormesis (“toxic stimulation”) or from addition of stimulating growth factors with the test material to the minimal medium used.
Variationskoefficienten beregnes som % af den gennemsnitlige specifikke væksthastighed ved hjælp af de trinvist beregnede daglige vækstrater for den pågældende replikat.
Note that the addition of inorganic nutrients should not have any direct effect because the test medium should maintain a surplus of nutrients throughout the test.
Der beregnes et gennemsnit af alle værdier beregnet i punkt 1.
Low dose stimulation can usually be ignored in EC50 calculations unless it is extreme.
Deraf fås den gennemsnitlige variationskoefficient for den beregnede trinvise daglige specifikke vækstrate i kontrolkulturreplikater.
However, if it is extreme, or an ECx value for low x is to be calculated, special procedures may be needed.
ECx er den koncentration af testkemikalie opløst i testsubstratet, der medfører en væksthæmning på x % (f.eks. 50 %) af testorganismen inden for en angiven eksponeringsperiode (som angives udtrykkeligt, hvis den er forskellig fra den fulde eller normale testperiode).
Deletion of stimulatory responses from the data analysis should be avoided if possible, and if available curve fitting software cannot accept minor stimulation, linear interpolation with bootstrapping can be used.
For klart at skelne mellem EC-værdier afledt af henholdsvis væksthastighed og udbytte anvendes betegnelsen »ErC« for væksthastighed (rate) og »EyC« for udbytte (yield).
If stimulation is extreme, use of a hormesis model may be considered (18).
Næringssubstrat er det komplette, syntetiske næringssubstrat, hvori algerne vokser, når de eksponeres for testkemikaliet.
Non toxic growth inhibition
Normalt er testkemikaliet opløst i testsubstratet.
Light absorbing test materials may give rise to a growth rate reduction because shading reduces the amount of available light.
Væksthastighed (gennemsnitlig specifik væksthastighed) er den logaritmiske biomasseforøgelse i eksponeringsperioden.
Such physical types of effects should be separated from toxic effects by modifying the test conditions and the former should be reported separately.
Laveste koncentration med observeret effekt (Lowest Observed Effect Concentration, LOEC) er den laveste testede koncentration, ved hvilken kemikaliet har vist statistisk signifikant (p < 0,05) vækstnedsættende virkning i forhold til kontrollerne inden for en given eksponeringsperiode.
Guidance may be found in (2) and (3).
Alle testkoncentrationer over LOEC skal dog have en skadelig virkning, der mindst svarer til den, der iagttages ved LOEC.
TEST REPORT
Kan disse to betingelser ikke opfyldes, skal der fyldestgørende redegøres for, hvordan den pågældende LOEC (og dermed NOEC) er valgt.
The test report must include the following:
Nuleffektkoncentration (No Observed Effect Concentration, NOEC) er testkoncentrationen umiddelbart under LOEC.
Test chemical:
Responsvariabel er en variabel, som anvendes til vurdering af den toksiske virkning og er afledt af vilkårlige målte parametre, der beskriver biomassen ved andre beregningsmetoder.
physical nature and relevant physical-chemical properties, including water solubility limit;
I nærværende testmetode er væksthastigheder og udbytte responsvariable, der er afledt ved måling af biomasse direkte eller af et af de nævnte surrogater.
chemical identification data (e.g., CAS Number), including purity (impurities).
Specifik væksthastighed er en responsvariabel, der er defineret som forholdet mellem ændringen i den naturlige logaritme for en observationsparameter (i nærværende testmetode, biomasse) og det tilsvarende tidsrum.
Test species:
Testkemikalie betyder et stof eller en blanding, som testes ved hjælp af denne testmetode.
the strain, supplier or source and the culture conditions used.
Udbytte er værdien af en målevariabel ved eksponeringsperiodens slutning minus værdien af variablen ved eksponeringsperiodens start, dvs. stigningen i biomasse under testen.
Test conditions:
Tillæg 2
date of start of the test and its duration;
Stammer, der er påvist at være velegnede til testen
description of test design:
Grønalger
test vessels, culture volumes, biomass density at the beginning of the test;
Pseudokirchneriella subcapitata (tidligere benævnt Selenastrum capricornutum), ATCC 22662, CCAP 278/4, 61.81 SAG
composition of the medium;
Desmodesmus subspicatus (tidligere benævnt Scenedesmus subspicatus), 86.81 SAG
test concentrations and replicates (e.g., number of replicates, number of test concentrations and geometric progression used);
Diatoméer
description of the preparation of test solutions, including use of solvents etc.
Cyanobakterier
culturing apparatus;
Kilder til stammer
light intensity and quality (source, homogeneity);
De anbefalede stammer fås som monokulturer fra følgende samlinger (i alfabetisk rækkefølge):
temperature;
Udseende og karakteristika af anbefalede arter
concentrations tested:
Udseende
the nominal test concentrations and any results of analyses to determine the concentration of the test chemical in the test vessels.
Krumme, skrueformede enkeltceller
The recovery efficiency of the method and the limit of quantification in the test matrix should be reported;
Ovale, hovedsagelig enkeltceller
all deviations from this test method;
Stave
method for determination of biomass and evidence of correlation between the measured parameter and dry weight;
Kæder af ovale celler
Results:
Størrelse (L × W) μm
pH values at the beginning and at the end of the test at all treatments;
Cellevolumen (μm3/celle)
biomass for each flask at each measuring point and method for measuring biomass;
Tørvægt af celle (mg/celle)
growth curves (plot of biomass versus time);
2-3 × 10– 8
calculated response variables for each treatment replicate, with mean values and coefficient of variation for replicates;
3-4 × 10– 8
graphical presentation of the concentration/effect relationship;
1-2 × 10– 8
estimates of toxicity for response variables e.g., EC50, EC10, EC20 and associated confidence intervals.
Særlige anbefalinger for dyrkning og håndtering af de anbefalede testarter
any stimulation of growth found in any treatment;
Pseudokirchneriella subcapitata og Desmodesmus subspicatus
any other observed effects, e.g. morphological changes of the algae;
Disse grønalgearter er sædvanligvis lette at holde i forskellige næringssubstrater.
discussion of the results, including any influence on the outcome of the test resulting from deviations from this test method.
Anabaena flos-aquae udvikler aggregater af sammenfiltrede kæder af celler.
The following definitions and abbreviations are used for the purposes of this test method:
Størrelsen af aggregaterne kan være forskellig, afhængigt af dyrkningsbetingelserne.
Biomass is the dry weight of living matter present in a population expressed in terms of a given volume;
Det kan være nødvendigt at bryde sådanne aggregater op, før biomassen kan bestemmes ved tælling i mikroskop eller med en elektronisk partikeltæller.
e.g., mg algae/litre test solution.
For at nedsætte variabiliteten af tællingerne kan kæderne brydes op ved sonikering af delprøver.
Usually “biomass” is defined as a mass, but in this test this word is used to refer to mass per volume.
Hvis sonikeringen fortsættes længere end nødvendigt for at bryde kæderne til kortere længder, kan cellerne blive ødelagt.
Also in this test, surrogates for biomass, such as cell counts, fluorescence, etc. are typically measured and the use of the term “biomass” thus refers to these surrogate measures as well.
Intensitet og varighed af sonikeringen skal være ens for alle behandlinger.
Chemical means a substance or mixture
For at medvirke til at kompensere for variabiliteten skal der tælles et tilstrækkeligt antal felter på hæmocytometeret (mindst 400 celler).
Coefficient of variation is a dimensionless measure of the variability of a parameter, defined as the ratio of the standard deviation to the mean.
Derved fås mere pålidelige tæthedsbestemmelser i mikroskop.
This can also be expressed as a percent value.
Til bestemmelse af det totale cellevolumen af Anabaena kan en elektronisk partikeltæller anvendes efter forudgående forsigtig sonikering for at bryde cellekæderne.
Mean coefficient of variation of average specific growth rate in replicate control cultures should be calculated as follows:
Sonikeringsenergien skal tilpasses, så bristning af celler undgås.
Calculate % CV of average specific growth rate out of the daily/section by section growth rates for the respective replicate;
Ved hjælp af hvirvelomrører eller en tilsvarende velegnet metode skal det sikres, at den anvendte algesuspension til podning af testbeholderne er godt opblandet og homogen.
Calculate the mean value out of all values calculated under point 1 to get the mean coefficient of variation of the daily/section by section specific growth rate in replicate control cultures.
Testbeholderne anbringes på et roterende eller frem- og tilbagegående rystebord ved ca. 150 omdr./min.
ECx is the concentration of the test chemical dissolved in test medium that results in an x % (e.g. 50 %) reduction in growth of the test organism within a stated exposure period (to be mentioned explicitly if deviating from full or normal test duration).
I stedet kan der anvendes intermitterende omrystning for at mindske Anabaenas tilbøjelighed til sammenklumpning.
To unambiguously denote an EC value deriving from growth rate or yield the symbol “ErC” is used for growth rate and “EyC” is used for yield.
I tilfælde af sammenklumpning skal der drages omsorg for, at prøverne til biomassebestemmelse bliver repræsentative.
Growth medium is the complete synthetic culture medium in which test algae grow when exposed to the test chemical.
Energisk omrystning kan være nødvendig før prøvetagning for at skille algeklumperne ad.
The test chemical will normally be dissolved in the test medium.
Synechococcus leopoliensis vokser som solitære, stavformede celler.
Growth rate (average specific growth rate) is the logarithmic increase in biomass during the exposure period.
Cellerne er meget små, hvilket komplicerer tælling i mikroskop til biomassebestemmelse.
Lowest Observed Effect Concentration (LOEC) is the lowest tested concentration at which the chemical is observed to have a statistically significant reducing effect on growth (at p < 0,05) when compared with the control, within a given exposure time.
Elektroniske partikeltællere, der er udstyret til tælling af partikler ned til ca. 1 μm, er gode.
However, all test concentrations above the LOEC must have a harmful effect equal to or greater than those observed at the LOEC.
In vitro fluorometrisk måling kan ligeledes anvendes.
When these two conditions cannot be satisfied, a full explanation must be given for how the LOEC (and hence the NOEC) has been selected.
Bemærk, at substratet skal indeholde silikat.
No Observed Effect Concentration (NOEC) is the test concentration immediately below the LOEC.
Navicula pelliculosa kan danne aggregater under visse vækstbetingelser.
Response variable is a variable for the estimation of toxicity derived from any measured parameters describing biomass by different methods of calculation.
På grund af dannelse af lipider vil algecellerne undertiden have tendens til at akkumulere i overfladefilmen.
For this test method growth rates and yield are response variables derived from measuring biomass directly or any of the surrogates mentioned.
Under sådanne omstændigheder må der ved udtagning af delprøver til biomassebestemmelse træffes særlige foranstaltninger for at sikre, at prøverne er repræsentative.
Specific growth rate is a response variable defined as quotient of the difference of the natural logarithms of a parameter of observation (in this test method, biomass) and the respective time period
Det kan være nødvendigt med kraftig omrystning, f.eks. med en hvirvelomrører.
Test chemical means any substance or mixture tested using this test method.
Målt med elektronisk partikeltæller
Yield is the value of a measurement variable at the end of the exposure period minus the measurement variable's value at the start of the exposure period to express biomass increase during the test.
Beregnet af størrelsen
Appendix 2
Hyppigste observerede væksthastighed i OECD-substrat ved en lysintensitet på ca. 70 μE m– 2 s– 1 og 21 °C
Strains Shown to be Suitable for the Test
Tillæg 3
Green algae
Næringssubstrater
Pseudokirchneriella subcapitata (formerly known as Selenastrum capricornutum), ATCC 22662, CCAP 278/4, 61.81 SAG
OECD-substrat:
Diatoms
Det oprindelige substrat fra OECD TG 201, også i henhold til ISO 8692
Cyanobacteria
EPA-substrat AAP, ligeledes i henhold til ASTM.
Sources of Strains