Effect Of Sampling Time Research Articles

Effects of sampling time on polysaccharides of Dendrobium catenatum under temperature-controlled condition

In order to reveal the accumulation trend of polysaccharides in Dendrobium catenatum and determine the effect of sampling time on polysaccharides, D. Catenatum D21 clone was harvested from January to December after culturing for 2 to 5 months in the growth chamber with constant temperature. Polysaccharides were determined by phenol-sulfuric acid method and the monosaccharide compositions were analyzed by pre-column derivative-UPLC. The results showed that the content of polysaccharide and its key component mannose was positively correlated with the culture time, but the contents of polysaccharides in all kinds of culture peaked from 5 to 6 months, which were consistent with the trend of field planting. The results suggested that the trend of polysaccharide accumulation in the plant could be related to the life rhythm of the sensory seasons of D. catenatum, which was significantly affected by the harvesting season, even under the constant condition of the culture chamber.

Explicit analytical tuning rules for digital PID controllers via the magnitude optimum criterion

Analytical tuning rules for digital PID type–I controllers are presented regardless of the process complexity. This explicit solution allows control engineers 1) to make an accurate examination of the effect of the controller's sampling time to the control loop's performance both in the time and frequency domain 2) to decide when the control has to be I, PI and when the derivative, D, term has to be added or omitted 3) apply this control action to a series of stable benchmark processes regardless of their complexity. The former advantages are considered critical in industry applications, since 1) most of the times the choice of the digital controller's sampling time is based on heuristics and past criteria, 2) there is little a–priori knowledge of the controlled process making the choice of the type of the controller a trial and error exercise 3) model parameters change often depending on the control loop's operating point making in this way, the problem of retuning the controller's parameter a much challenging issue. Basis of the proposed control law is the principle of the PID tuning via the Magnitude Optimum criterion. The final control law involves the controller's sampling time Ts within the explicit solution of the controller's parameters. Finally, the potential of the proposed method is justified by comparing its performance with the conventional PID tuning when controlling the same process. Further investigation regarding the choice of the controller's sampling time Ts is also presented and useful conclusions for control engineers are derived.

Quantification and Systematic Characterization of Stuttering-Like Disfluencies in Acquired Apraxia of Speech.

The purpose of this article is to quantify and describe stuttering-like disfluencies in speakers with acquired apraxia of speech (AOS), utilizing the Lidcombe Behavioural Data Language (LBDL). Additional purposes include measuring test-retest reliability and examining the effect of speech sample type on disfluency rates. Two types of speech samples were elicited from 20 persons with AOS and aphasia: repetition of mono- and multisyllabic words from a protocol for assessing AOS (Duffy, 2013), and connected speech tasks (Nicholas & Brookshire, 1993). Sampling was repeated at 1 and 4 weeks following initial sampling. Stuttering-like disfluencies were coded using the LBDL, which is a taxonomy that focuses on motoric aspects of stuttering. Disfluency rates ranged from 0% to 13.1% for the connected speech task and from 0% to 17% for the word repetition task. There was no significant effect of speech sampling time on disfluency rate in the connected speech task, but there was a significant effect of time for the word repetition task. There was no significant effect of speech sample type. Speakers demonstrated both major types of stuttering-like disfluencies as categorized by the LBDL (fixed postures and repeated movements). Connected speech samples yielded more reliable tallies over repeated measurements. Suggestions are made for modifying the LBDL for use in AOS in order to further add to systematic descriptions of motoric disfluencies in this disorder.

Effect of sampling time in the laboratory investigation of braided rivers

AbstractWe focus on the measurement of the bed‐elevation of braided networks in flume experiments. In particular, the effect of the survey frequency on the measurement accuracy is studied. To this aim, an innovative measurement system is adopted. It consists of a laser‐ultrasonic sensor and can survey the bed‐elevation under flowing water. This measurement system was used to profile a flume transect with a frequency of 4 min, without stopping the water discharge. By this technique, the topography of a single transect was continuously acquired during the evolution of a braided river model. Twelve braided rivers generated with different experimental conditions were studied. The main results are (i) there exists a threshold survey frequency (4–8 min in our analysis) which guarantees that the morphological evolution of the braiding channels is fully measured; (ii) if this threshold frequency of survey is exceeded, significant errors occur in the balance of the eroded/deposited sediments and in the evaluation of the bed‐elevation dynamics; and (iii) these errors depend on the river stream power.

Limited genomic consequences of hybridization between two African clawed frogs, Xenopus gilli and X. laevis (Anura: Pipidae)

The Cape platanna, Xenopus gilli, an endangered frog, hybridizes with the African clawed frog, X. laevis, in South Africa. Estimates of the extent of gene flow between these species range from pervasive to rare. Efforts have been made in the last 30 years to minimize hybridization between these two species in the west population of X. gilli, but not the east populations. To further explore the impact of hybridization and the efforts to minimize it, we examined molecular variation in one mitochondrial and 13 nuclear genes in genetic samples collected recently (2013) and also over two decades ago (1994). Despite the presence of F1 hybrids, none of the genomic regions we surveyed had evidence of gene flow between these species, indicating a lack of extensive introgression. Additionally we found no significant effect of sampling time on genetic diversity of populations of each species. Thus, we speculate that F1 hybrids have low fitness and are not backcrossing with the parental species to an appreciable degree. Within X. gilli, evidence for gene flow was recovered between eastern and western populations, a finding that has implications for conservation management of this species and its threatened habitat.

Hair cortisol and testosterone concentrations and semen production of Bos taurus bulls

The experiment was aimed to evaluate the usefulness of hair cortisol concentrations (HCC) in revealing the activation of the hypothalamic-pituitary-adrenal (HPA) axis due to the passage of young bulls from genetic rearing stations to artificial insemination (AI) centre and the influence of this passage on hair testosterone concentrations (HTC). Hair samples on 33 yearling bulls were collected at the time of arrival (ST1) to the AI centre and 3 more hair samples (ST2, ST3, ST4) were collected at monthly intervals. After the end of quarantine each animal was submitted to the standard procedures for collection and production of semen. Overall HCC were significantly affected by period of collection (p < .01). In particular, HCC was higher in samples obtained after finishing the quarantine period (ST2) compared with those obtained on ST1. After ST2, the HCC decreased reaching at ST4 a value similar to that recorded at ST1. An effect of sampling time on HTC was not found (p > .05). The effect of breed was observed only for HTC that was higher in PRI than BS (p < .01). The HCC group have not influenced the semen variables (p > .05). On the contrary, the effect of breed was evident. The results of this study replicated the effects of a major environmental stressor on mean cortisol concentrations assessed in hair, and add to the growing body of evidence that HCC is an effective and simply collected marker for long-term activity of the HPA system in response to persistent environmental challenge.

Day-time variation of serum periostin in asthmatic adults treated with ICS/LABA and adults without asthma

BackgroundWe aimed to determine the effect of sampling time during the day on serum periostin levels in adult participants with and without asthma.MethodsSerum periostin was measured at 2-h intervals from 0800 to 1800 h in 16 adult participants with stable asthma prescribed inhaled corticosteroid and long-acting beta-agonist therapy, and in 16 otherwise healthy participants without asthma. Mixed linear models were used to compare time zero (08:00 h) with subsequent measurement time for serum periostin for both groups.ResultsIn both asthma and non-asthma, the mean (SD) serum periostin levels continuously reduced during the day from 53.5 (13.6) ng/mL at 0800 h to 50.9 (13.4) ng/mL at 1800 h (difference log periostin −0.05, P ≤ 0.001) and 50.5 (13.0) ng/mL at 0800 h to 46.2 (11.5) ng/mL at 1800 h (difference log periostin −0.08, P ≤ 0.001) respectively.ConclusionsPeriostin values are higher in the morning compared with the afternoon in asthmatic and non-asthmatic adults. The small magnitude of the variation in serum periostin levels suggests that the time of day in which the serum periostin measurements are made is unlikely to influence treatment decisions if a specific serum periostin level is used to predict treatment responsiveness.Trial registration Australia New Zealand Trials Registry (ACTRN12614000072617)

Direct fitting measurement of gas content in coalbed and selection of reasonable sampling time

In this study, we selected 9 typical coal samples with different metamorphic grades as the study subjects, measured their initial 30-min gas desorption at 30°C and different pressure using a self-developed gas adsorption/desorption device. Based on the characteristics of gas desorption from coal samples, we proposed a direct fitting method for measurement of gas content in coalbed, analyzed the effects of sampling time on the measurement results and determined the reasonable sampling time of coal samples with different metamorphic grades at different gas adsorption pressure at equilibrium. The results show that (1) the error of gas contents obtained using the direct fitting method relative to that obtained using indirect method is less than 10%, which meets the actual on-site requirements and verifies the feasibility of the direct fitting method; (2) when the relative error is controlled within ±10%, the reasonable sampling time of coal samples is linearly related to the gas adsorption pressure at equilibrium; (3) the reasonable sampling time of coal samples with the same metamorphic grade exhibits a shortening trend with increasing gas adsorption pressure at equilibrium; (4) for coal samples with similar gas adsorption pressure at equilibrium, the reasonable sampling time of coal samples displays a shortening trend with increasing metamorphic grade. Overall, the study provides a basis for improving the measurement accuracy of gas content in coalbed.

Nonlinear dynamics of hardware-in-the-loop experiments on stick–slip phenomena

A single degree-of-freedom nonlinear mechanical model of the stick–slip phenomenon is studied when the Stribeck-type friction force is emulated by means of a digitally controlled actuator. The relative velocity of the slipping contact surfaces is considered as bifurcation parameter. The original physical system presents subcritical Hopf bifurcation with a wide bistable parameter region where stick–slip and steady-state slipping are both stable locally. Hardware-in-the-loop experiments are performed with a physical oscillatory system subjected to the emulated Stribeck forces. The effect of sampling time is studied with respect to the stability and nonlinear behavior of this experimental system. The existence of subcritical Neimark–Sacker bifurcations are proven in the digital system, the stability and bifurcation characteristics of the continuous and the digital systems are compared, and the counter-intuitive stabilizing effect of sampling time is shown both analytically and experimentally. The conclusions draw the attention to the limitations of hardware-in-the-loop experiments when the corresponding systems are strongly nonlinear.

Effects of Soil Sampling Time on Soil Physical Parameters and Infiltration in Sugarcane Fields

Effects of Soil Sampling Time on Soil Physical Parameters and Infiltration in Sugarcane Fields

Effect of a Blend of Essential Oils on Buffalo Rumen Microbial and Enzyme Profiles and In Vitro Feed Fermentation

Three rumen-fistulated adult Murrah buffaloes (BW 426±45 kg) were arranged in a 3×3 LSD. The treatments involved supplementation of a blend (BEO-CL) of clove bud oleoresin and lemongrass oil (in 1:1 ratio) at the rate of 0, 0.75 and 1.5% of BW. After 20d of feeding, the rumen liquor and rumen contents were sampled before (0h) and 4h after feeding and analyzed for various parameters. There was neither any effect of feed additive nor sampling time on the concentration of VFAs, NH3-N, lactic acid and activities of select enzymes (carboxymethylcellulase, avicelase, xylanase, amylase, β-glucosidase, α-glucosidase and acetyl esterase). The population of rumen bacteria, fungi, ciliate protozoa, Fibrobacter succinogenes, Ruminococcus flavefaciens, Ruminococcus albus and methanogens were not affected by BEO-CL supplementation. In vitro gas production test to evaluate various feedstuffs namely hays (berseem, oat and maize); dry roughages (wheat straw, paddy straw and sugarcane bagasse) complete feeds with 20:80, 35:65 and 50:50 concentrate: roughage ratio) as substrates was conducted using rumen liquor of these buffaloes as inocula. There was an increase in gas production with rumen liquor of BEO-CL supplemented buffaloes irrespective of substrate. Methane production was decreased with 0.75% BEO-CL supplemented inoculum but not with paddy straw and sugarcane bagasse. The in vitro true digestibility (IVTD) of feed was increased with BEO-CL inoculum only with complete diet having 20:80 concentrate:roughage ratio as substrate. It is concluded that BEO-CL at the level of 0.75% of BW did not affect rumen characteristics and major microbial populations but inhibited in vitro methane production; hence, it can be further explored for its use as a feed additive to mitigate methane emission in buffaloes.

The Influence of Time and Temperature at Carcass Boning on Subprimal Temperature, pH, and Color Measurements of New Zealand Beef

ObjectivesThirty-two carcasses were selected for this study from a commercial abattoir in New Zealand. One side was hot boned (HB) where fabrication occurred within 90 min post mortem, while the other side was subjected to a traditional cold boning procedure (CB) where the carcasses were chilled overnight and fabricated 17 to 20 h post mortem. Five subprimals were collected from each side, including the strip loin, cube roll, tenderloin, rump, and topside. The subprimals were further fabricated leaving only the longissimus lumborum (LL), longissimus thoracis (LT), psoas major (PM), gluteus medius (GM), and semimembranosus (SM).Materials and MethodsSubjective and objective color evaluation was conducted at two times in the fabrication process. Initial readings were taken when the subprimals were removed from the carcass. Bloom time was approximately 5 min from subrimal excision or from subprimal removal from vacuum packaging for initial and ultimate, respectively. Objective color was taken using a portable Minolta colorimeter (CM-2002; Minolta Camera Co., LTD, Osaka, Japan), averaging three readings per muscle. Subjective color was evaluated using Meat Standards Australia color chips (1A, 1B, 1C, 2–7). Initial temperature and pH were evaluated simultaneously at harvest using a portable handheld probe (TPS Model WP-90, TPS Pty Ltd., Brendale, QLD, Australia). Ultimate measurements were taken at d 2 for the CB subprimals and d 3 for the HB subprimals. Day varied between chilling treatment due to logistical restrictions. Data were analyzed as a split plot design using GLIMMIX procedure in SAS. Data were analyzed by muscle, evaluating the fixed effects of chilling treatment and sampling time. Significance was recognized at P < 0.05.ResultsFor subjective color, L*, a*, and b*, the interaction between chilling and sampling time was observed (P < 0.02) for all muscles (except PM a*). At carcass fabrication HB muscles were subjectively darker than CB muscles and had lower L*, a*, and b*, indicating HB was darker, less red, and less yellow than CB muscles. A similar trend was observed at steak fabrication; however, the magnitude of differences between HB and CB was greatly reduced. A similar trend to color results was detected for pH and temperature, as the chilling treatment by sampling time interaction was detected (P < 0.01) for all five muscles. Subprimals from HB sides had lower initial pH readings, but the CB muscles had lower ultimate pH values compared to their HB counterparts.ConclusionHot boning resulted in slightly higher, yet still acceptable, ultimate pH in all 5 muscles, which translated to darker muscle color scores, assessed both subjectively and objectively. These differences in color and pH should be considered when processors are implementing either of these carcass chilling and fabrication regimes.

IDENTIFIKASI KERAGAMAN JENIS BAKTERI PADA PROSES PENGOLAHAN LIMBAH CAIR INDUSTRI MINUMAN DENGAN LUMPUR AKTIF LIMBAH TAHU

The method of activated sludge is a wastewater treatment method that utilizes microbial growth processes are suspended. One of the microbes that play a role in wastewater treatment systems with activated sludge are bacteria. The purpose of this research was to determine the effect of sampling time and the combination of retention time on levels of pH, BOD, TSS, H 2 S and turbidity effluent of beverage industry with waste activated sludge of tofu and identify the bacterial isolates obtained from the beverage industry wastewater treatment with activated sludge waste of tofu and to know the diversity of types of bacteria that play a role in it. The diversity of bacteria identified in the beverage industry wastewater treatment by activated sludge are five types of Bacillus sp, Acinetobacter sp, Staphylococcos sp, Cardiobacterium sp, and Mycoplasma sp. These bacteria are most likely a bacterium that plays a role in the degradation of the beverage industry wastewater. Activated sludge method, it is also able to improve water quality, especially for TSS parameter (<200 mg/l) and H 2 S (<0.05 mg/l). Sampling time in the morning better than afternoon in the improvement of water quality parameters; for the retention time of 8 hours of sample treatment is better than 6 hours. Thus, the retrieval time (morning, afternoon) and the retention time of wastewater samples generate all test parameters better than the control.

Numerical investigation on flow-induced structural vibration and noise in centrifugal pump

A full scale structural vibration and noise induced by flow was simulated by a hybrid numerical method. An interior flow field was solved by large eddy simulation firstly. The sliding mesh technique was applied to take into account the impeller-volute interaction. A sensitivity analysis on effects of near-wall grid size and sampling time on amplitude of pressure pulsations was performed to impose appropriate vibration exciting source. Computed modal of pump components was validated by experimental results, before the volute vibration and sound field were simulated using a coupled vibro-acoustic model. The numerical results indicated that the amplitude of pressure fluctuation, especially on those points located at near the volute tongue, strongly depended on near-wall grid size. The dominated frequency of the vibration velocity of volute was also blade-passing frequency (BPF), which was in according with frequency spectral characteristics of unsteady pressure fluctuation. Directivity distribution of radiation acoustic field excited by volute vibration was typical dipoles. This study shows that it is feasible to use the hybrid numerical method to evaluate the flow-induced vibration and noise generated in centrifugal pump.

Effects of transgenic cry1Ie maize on non-lepidopteran pest abundance, diversity and community composition.

Non-lepidopteran pests are exposed to, and may be influenced by, Bt toxins when feeding on Bt maize that express insecticidal Cry proteins derived from Bacillus thuringiensis (Bt). In order to assess the potential effects of transgenic cry1Ie maize on non-lepidopteran pest species and ecological communities, a 2-year field study was conducted to compare the non-lepidopteran pest abundance, diversity and community composition between transgenic cry1Ie maize (Event IE09S034, Bt maize) and its near isoline (Zong 31, non-Bt maize) by whole plant inspections. Results showed that Bt maize had no effects on non-lepidopteran pest abundance and diversity (Shannon-Wiener diversity index, Simpson's diversity index, species richness, and Pielou's index). There was a significant effect of year and sampling time on those indices analyzed. Redundancy analysis indicated maize type, sampling time and year totally explained 20.43% of the variance in the non-lepidopteran pest community composition, but no association was presented between maize type (Bt maize and non-Bt maize) and the variance. Nonmetric multidimensional scaling analysis showed that sampling time and year, rather than maize type had close relationship with the non-lepidopteran pest community composition. These results corroborated the hypothesis that, at least in the short-term, the transgenic cry1Ie maize had negligible effects on the non-lepidopteran pest abundance, diversity and community composition.

Arbuscular mycorrhizal fungal communities in buffelgrass pasture under intercropping and shading systems in Brazilian semiarid conditions

The intercropping of grasses and legumes has been suggested as an alternative for ensuring pasture sustainability. However, few studies have focused on the impact of intercropping and shading on the soil microbiota in semi-arid regions. The goal of this study was to evaluate the effects of intercropping a grass, Cenchrus ciliaris, with a legume, Clitoria ternatea, under different levels of shading, on the C. ciliaris carbohydrate concentration and the arbuscular mycorrhizal fungal (AMF) community over time. Soil samples were collected at four sampling times: before intercropping (BI) and after 120, 165 and 210days cultivation. Four levels of shading were tested: 0 (full sunlight), 26, 39 and 55%. In the intercropped system, mycorrhizal colonization was higher under lower shading levels after 120 and 165days cultivation, but the number of glomerospores was higher under higher shading levels. After 165days cultivation, the carbohydrate concentrations were higher under full sunlight. After 210days cultivation, the reducing carbohydrate concentrations were higher in the intercropped system. Thirty-one AMF species were detected; Acaulospora and Glomus species were predominant compared with the remaining genera. This study showed that AMF community composition was relatively similar between shading and intercropping by multidimensional scaling (MDS) and PERMANOVA analysis, and it was observed only sampling time effect on the AMF community. The Shannon diversity index showed a reduction in AMF diversity from 210days of cultivation and an increase in the AMF species richness over time. It was concluded that pastures of C. ciliaris under shading and intercropping with C. ternatea did not modify the AMF community composition. However, the results suggest that intercropping of these plant species may result in AMF species selection over time.

Use of response surface methodology for the assessment of changes in the volatile composition of Moscato bianco (Vitis vinifera L.) grape berries during ripening

The changes in the volatile composition of Moscato bianco grapes were evaluated during ripening. Grape berries were sampled for five weeks (16–20 °Brix) and sorted for each date in ten density classes (1.05–1.12g/cm3). The highest total concentration of free terpenes was found at 19.3 °Brix; however, total concentration of the bound fraction increased significantly throughout ripening. Response surface methodology was used to assess the simultaneous effect of sampling time and berry density on the volatile composition, which was satisfactorily fitted to regression models for some key terpene compounds. Total free and bound terpenes were more affected by grape density than by sampling date. The same behaviour was observed for free and bound linalool and bound nerol, whereas the stronger effect of sampling date was exhibited for bound t-rose oxide, c-rose oxide and geraniol. The results showed that the sampling strategy impacted strongly on the aroma quality of berries.

Breakthrough of 1,3-Dichloropropene and Chloropicrin from 600-mg XAD-4 Air Sampling Tubes

Accurately measuring air concentrations of agricultural fumigants is important for the regulation of air quality. Understanding the conditions under which sorbent tubes can effectively retain such fumigants during sampling is critical in mitigating chemical breakthrough from the tubes and facilitating accurate concentration measurements. Using laboratory experiments, we studied the effects of air flow rate (100–1000 mL min−1) and sampling time (2–16 h) on the breakthrough of co-applied chloropicrin (CP) and 1,3-dichloropropene (1,3-D) from 600-mg XAD-4 sorbent tubes. Due to the reversible adsorption of the chemicals, it was not possible to determine a tube adsorption capacity that was true across all flow and sample time conditions. Flow rate exerted the stronger influence on breakthrough, particularly for CP, with flow rates in excess of 200 mL min−1 resulting in significant system losses even at the shortest sampling time (2 h). A flow rate of 200 mL min−1 should therefore not be exceeded, irrespective of flow rate. With the use of a single tube (no backup), sampling times up to 4 h showed no system losses (100 % retention). Using a primary and backup tube, sampling periods up to 16 h also resulted in retention of all the added chemical masses. The information will be useful in establishing effective air quality monitoring programs following fumigation events.

The self-assemble of natural cyclodextrins in aqueous solutions: Application of miniature permeation studies for critical aggregation concentration (cac) determinations

Permeation techniques can be applied to determine the critical aggregation concentration (cac) of natural cyclodextrins (CDs) in aqueous solutions although the method is both laborious and time consuming. In the present study, the permeation technique was modified and the influence of osmotic pressure, sampling time, CD concentration and molecular weight-cut off (MWCO) of the membrane were investigated in two different permeation units, that is Franz diffusion cells and Slide-A-Lyzer™ MINI Dialysis. While both the osmotic pressure and CD concentration affect the steady state flux in both permeation units, effects of sampling time and the MWCO of the mounted membrane were only observed in the Franz diffusion cells. The osmotic effect was negligible in the Slide-A-Lyzer™ MINI Dialysis units. The modified permeation technique using Slide-A-Lyzer™ MINI Dialysis units was then used to determine the cac of natural CDs in water. The cac of αCD, βCD and γCD was 1.19±0.17, 0.69±0.05 and 0.93±0.04% (w/v), respectively. The results indicated that the cac values depended on their intrinsic solubility. Moreover, the cac value of γCD in aqueous hydrocortisone/γCD inclusion complex solution was identical to the γCD cac value determined in pure water.

Empirical analysis of BMD metrics in genetic toxicology part II: in vivo potency comparisons to promote reductions in the use of experimental animals for genetic toxicity assessment.

Genotoxicity tests have traditionally been used only for hazard identification, with qualitative dichotomous groupings being used to identify compounds that have the capacity to induce mutations and/or cytogenetic alterations. However, there is an increasing interest in employing quantitative analysis of in vivo dose-response data to derive point of departure (PoD) metrics that can be used to establish human exposure limits or margins of exposure (MOEs), thereby supporting human health risk assessments and regulatory decisions. This work is an extension of our companion article on in vitro dose-response analyses and outlines how the combined benchmark dose (BMD) approach across included covariates can be used to improve the analyses and interpretation of in vivo genetic toxicity dose-response data. Using the BMD-covariate approach, we show that empirical comparisons of micronucleus frequency dose-response data across multiple studies justifies dataset merging, with subsequent analyses improving the precision of BMD estimates and permitting attendant potency ranking of seven clastogens. Similarly, empirical comparisons of Pig-a mutant phenotype frequency data collected in males and females justified dataset merging across sex. This permitted more effective scrutiny regarding the effect of post-exposure sampling time on the mutagenicity of N-ethyl-N-nitrosourea observed in reticulocytes and erythrocytes in the Pig-a assay. The BMD-covariate approach revealed tissue-specific differences in the induction of lacZ transgene mutations in Muta™Mouse specimens exposed to benzo[a]pyrene (BaP), with the results permitting the formulation of mechanistic hypotheses regarding the observed potency ranking. Lastly, we illustrate how historical dose-response data for assessments that examined numerous doses (i.e. induced lacZ mutant frequency (MF) across 10 doses of BaP) can be used to improve the precision of BMDs derived from datasets with far fewer doses (i.e. lacZ MF for 3 doses of dibenz[a,h]anthracene). Collectively, the presented examples illustrate how innovative use of the BMD approach can permit refinement of the use of in vivo data; improving the efficacy of experimental animal use in genetic toxicology without sacrificing PoD precision.