Cent Deviation Research Articles

Analysis of Forecasted Rainfall Across Blocks in Guntur District, Andhra Pradesh, India

This paper represents a block and district level analysis of agro meteorological forecasted rainfall of Guntur district, Andhra Pradesh, during 2022-23. The forecasted rainfall data which was issued by IMD, Amaravathi, Guntur, Andhra Pradesh and the data was validated by employing both qualitative (success rate) and quantitative analysis (Ratio score, Hanssen and Kuipers Score and Probability of Detection). The quantitative analysis was performed by calculating ratio score analysis values ranged from 0.6 to 0.9 during the monsoons, indicating good forecast. Hansen and Kuipers score test results found to have good agreement during north east monsoon (0.5 to 0.8) with highest score values which indicates better forecast agreement, followed by monsoon period (0.3 to 0.5) and south west monsoon (0 to 0.3). Probability of Detection values found in the range of 0.7 to 1.0 indicated that better score values resulting in good forecast during the monsoon seasons. Whereas, the qualitative analysis was performed by deriving success rate for forecasted rainfall accuracy and the results reported that highest success rate was observed during north east monsoon followed by south west monsoon across different blocks and also in the entire Guntur district. The per cent deviation in the analysed data might be due to the spatio-temporal variations in the rainfall distribution pattern over the study area.

Usability of monthly ERFS (Extended Range Forecast System) to predict maize yield using DSSAT (Decision Support System for Agro-technology Transfer) model over Erode District of Tamil Nadu

Extended Range of Forecast Service (ERFS) is highly useful for planning of cropping season and midterm correction at the farm level. The medium-range and long-range forecast validation have many studies, whereas ERF has less that needs to be studied. Maize is an important field crop in India after rice and wheat. Therefore, the prediction of maize yield has significant importance. In the present study, ERFS data were validated by correlation analysis using monthly observed rainfall frequency and intensity. This data was imported to DSSAT (Decision Support System for Agro-technology Transfer) to simulate maize yield of Erode district of Tamil Nadu. The model output and actual yield data from Erode were compared. Forecasted monthly total rainfall was correlated at a rate of 0.97r value with that observed. Yield simulation of maize was done using DSSAT by integrating ERFS data and the observed monthly data. Mean per cent deviation among the yields of observed weather and the disaggregated one tended to be -15.7 %. The average deviation between the yields of ERF forecasted weather data and actual yield was very high ( -29.7 % ) for Erode. Mean % deviation between the yields of observed weather and the actual yield was -14.7 %. Downscaled and accurate weather forecasts could be facilitated for yield prediction of crops by DSSAT model. Yield prediction by the model under observed weather was convenient and usable. Model under-predicted the yields when using ERF data. Both model and ERF forecast need to be improved further for higher resolution.

Chemistry Lesson Plan Design and Teaching: A Case Study of Senior Secondary Schools in the Urban Regions of the Gambia

This study aimed to understand chemistry lesson plan design and teaching at secondary schools with 14 teachers and 282 students, grade 11, through Randomized Post-test Control Group Design, placed in each experimental and control group. The experimental group was taught using multifunctional approaches, social constructivism, and laboratory experimentations. The control group was taught using traditional methods and laboratory experimentations, focusing on concepts of acids, bases, and salts. Indicators such as lesson topic, objectives, activities, evaluations, and conclusions were thematically reviewed, while teaching categories such as lesson organisation, activities teaching, pedagogical approaches, collaborative learning, teacher- student interaction, instructional resources, and students' academic performance were quantitatively analysed. Descriptive statistics were used to obtain frequency per cent (%), weighted mean, and standard deviation. The finding shows that teachers were knowledgeable about designing a chemistry lesson even though they followed the same trajectory and were inadequately prepared. In addition, only pedagogical approaches and instructional resources were moderately utilised among the teaching categories. Further, students in the experimental group performed better academically, as measured by their mean difference (12.121), significant (t = 6.142, p =.000), which may be attributed to paradigm-shifting from teacher-centred to the students-centred, instructional resources, students’ ability, and motivation. Therefore, the current lesson plan design as a case study in the chemistry classroom implies that effective lesson plans and teaching can lead to better learning of core competencies in the Gambian context if they were to be monitored and improved extensively. However, a further study may be needed by comparing the difference between pre-test and post-test scores, as this will indicate a better measure

Development and Validation of an Analytical HPLC Method to Assess Chemical and Radiochemical Purity of [68Ga]Ga-NODAGA-Exendin-4 Produced by a Fully Automated Method.

Background: Glucagon-like peptide 1 receptor (GLP-1R) is preferentially expressed in pancreatic islets, especially in β-cells, and highly expressed in human insulinomas and gastrinomas. In recent years several GLP-1R–avid radioligands have been developed to image insulin-secreting tumors or to provide a tentative quantitative in vivo biomarker of pancreatic β-cell mass. Exendin-4, a 39-amino acid peptide with high binding affinity to GLP-1R, has been labeled with Ga-68 for imaging with positron emission tomography (PET). Preparation conditions may influence the quality and in vivo behavior of tracers. Starting from a published synthesis and quality controls (QCs) procedure, we have developed and validated a new rapid and simple UV-Radio-HPLC method to test the chemical and radiochemical purity of [68Ga]Ga-NODAGA-exendin-4, to be used in the clinical routine. Methods: Ga-68 was obtained from a 68Ge/68Ga Generator (GalliaPharma®) and purified using a cationic-exchange cartridge on an automated synthesis module (Scintomics GRP®). NODAGA-exendin-4 contained in the reactor (10 µg) was reconstituted with HEPES and ascorbic acid. The reaction mixture was incubated at 100 °C. The product was purified through HLB cartridge, diluted, and sterilized. To validate the proposed UV-Radio-HPLC method, a stepwise approach was used, as defined in the guidance document released by the International Conference on Harmonization of Technical Requirements of Pharmaceuticals for Human Use (ICH), adopted by the European Medicines Agency (CMP/ICH/381/95 2014). The assessed parameters are specificity, linearity, precision (repeatability), accuracy, and limit of quantification. Therefore, a range of concentrations of Ga-NODAGA-exendin-4, NODAGA-exendin-4 (5, 4, 3.125, 1.25, 1, and 0.75 μg/mL) and [68Ga]Ga-NODAGA-exendin-4 were analyzed. To validate the entire production process, three consecutive batches of [68Ga]Ga-NODAGA-exendin-4 were tested. Results: Excellent linearity was found between 5–0.75 μg/mL for both the analytes (NODAGA-exendin-4 and 68Ga-NODAGA-exendin-4), with a correlation coefficient (R2) for calibration curves equal to 0.999, average coefficients of variation (CV%) < 2% (0.45% and 0.39%) and average per cent deviation value of bias from 100%, of 0.06% and 0.04%, respectively. The calibration curve for the determination of [68Ga]Ga-NODAGA-exendin-4 was linear with a R2 of 0.993 and CV% < 2% (1.97%), in accordance to acceptance criteria. The intra-day and inter-day precision of our method was statistically confirmed using 10 μg of peptide. The mean radiochemical yield was 45 ± 2.4% in all the three validation batches of [68Ga]Ga-NODAGA-exendin-4. The radiochemical purity of [68Ga]Ga-NODAGA-exendin-4 was >95% (97.05%, 95.75% and 96.15%) in all the three batches. Conclusions: The developed UV-Radio-HPLC method to assess the radiochemical and chemical purity of [68Ga]Ga-NODAGA-exendin-4 is rapid, accurate and reproducible like its fully automated production. It allows the routine use of this PET tracer as a diagnostic tool for PET imaging of GLP-1R expression in vivo, ensuring patient safety.

3D pavement macrotexture parameters from close range photogrammetry

ABSTRACT The 3D modelling of pavement surface using digital close-range photogrammetry (CRP) was thoroughly analyzed in this work. The accuracy and precision of the technique were effectively measured. A digital 3D model generated by CRP was compared to the model generated by a laser scanner, considered here as a benchmark for precision. The precision, measured as per cent deviation from a computer-generated model, considered here as the true value, was found to be 3.4% and the accuracy, measured as per cent error, was found to be 4.2%. A study involving 85 locations and 5 different surface types was also conducted to compare the calculated macrotexture parameters to those obtained from the Sand Patch Test and British Pendulum Test (BPT). The creation of a 3D surface model allowed the investigation of parameters other than the averages of height and depth proposed in the current standards. Moreover, the process described in this work can be automated and with proper standardization could be used for management and decision making at the infrastructure's network level. The British pendulum did not show a high correlation to the 3D macrotexture parameters except for the Mean Texture Depth (MTD) calculated from the sand patch itself (R 2 = 59.7%).

Analysing water productivity response to sowing window, irrigation levels and mulching using CERES-wheat model

Field experiments were carried out during rabi seasons of 2015-16 and 2016-17 at the Research Farm, Punjab Agricultural University, Ludhiana. Wheat variety PBW 621 was sown on three dates (D1: 4th week of October, D2: 2nd week of November and D3: 4th week of November) with two irrigation levels (I1: IW/ CPE = 0.9, I2: At CRI, 5-6 weeks after 1st irrigation, 3-4/5-6 weeks after 2nd irrigation, 2/4 weeks after 3rd irrigation as per dates of sowing) and mulch application (M1: without mulch, M2: straw mulch @ 5 t ha-1). Earlier sown mulch applied crop with four post-sowing irrigations produced highest (5312.5 kg ha-1) and late sown without mulch application crop with irrigation @IW/CPE = 0.9 produced lowest grain yield (3900.5 kg ha-1). Simulation results depicted -1.1 to 16.8 per cent deviation in crop yield, -1.4 to -21.0 per cent in water use and 12.7 to 45.5 per cent in water productivity. Increase in temperature from 1oC to 3oC decreased wheat yield by 6.3 to 27.0 per cent under D1 and 3.3 to 17.6 per cent under D2, however, it increased from 8.1 to 16.2 per cent under D3, indicating D3 as most appropriate under future warming scenarios. Increase in CO2 concentration decreased water use and increased yield and water productivity.

Poverty, Unemployment and Food Insecurity: Empirical Evidence from Nigeria

The high incidence of poverty in Nigeria coupled with the alarming rate of unemployment has raised concerns among experts as to their likely relationship with food insecurity. This study examined the nexus between poverty, unemployment and food insecurity using the Johansen cointegration test and the vector error correction model. The result from the Johansen cointegration test suggests a long-run relationship between food insecurity, poverty and unemployment. Findings from the vector error correction analysis showed a positive but insignificant relationship between poverty and food insecurity such that a percentage change in poverty in the current period is associated with a 0.09 per cent increase in food insecurity on average, ceteris paribus. Besides, a positive and significant relationship subsists between unemployment and food insecurity where an increase in unemployment exacerbated the latter. Clearly, a 1 per cent deviation in the previous period unemployment level is associated with a 1.2 per cent degeneration of the food insecurity position in the short run. In the same vein, a 1 per cent change in unemployment in the current period causes a 1.5 per cent aggravation of food insecurity. Following the findings, this study recommends a multi sector-specific approach to solving the issue of poverty in Nigeria targeting agriculture and its employment generating capacity, creating the enabling environment through infrastructure development and improving the ease of doing business for the private sector to strive and enhance its employment generating capacities. The study concludes with a call for the implementation of a holistic food security policy targeting improvement in crop yield, internal security problems and the proper funding of agriculture to be effective.

The Effect of Wearing Foam and Etymotic Earplugs on Classical Musicians’ Pitch Perception

The purpose of this study was to investigate the effect of wearing earplugs on classical musicians’ pitch perception across three experimental conditions: no earplugs, foam earplugs, and Etymotic earplugs. Participants were graduate and undergraduate music majors attending a large school of music in the southeastern United States ( N = 72). Participants adjusted the pitch of five complex stimulus tones (C#4, C#5, C#3, G#4, and F#3) using a continuous response digital interface until they believed the interval was in tune with an oboe (C#4) reference tone. Participants tended to tune flat when the stimulus tone was presented flat and to tune sharp when it was presented sharp across all three earplug conditions. Overall cent deviation in tuning responses showed that in both directional and absolute deviation analyses, listeners were most accurate when tuning without earplugs, then when using Etymotic earplugs, and least accurate with foam earplugs. Significant differences, however, were limited to specific intervals and in magnitudes not likely to be perceived. Although more research is needed, the use of Etymotic earplugs may provide valuable protection against noise-induced hearing loss with negligible effects on pitch perception. Implications for musicians and recommendations for future research are discussed.

Anomalous azimuthal variations with 360° periodicity of Rayleigh phase velocities observed in Scandinavia

SUMMARY We use the recently deployed ScanArray network of broad-band stations covering most of Norway and Sweden as well as parts of Finland to analyse the propagation of Rayleigh waves in Scandinavia. Applying an array beamforming technique to teleseismic records from ScanArray and permanent stations in the study region, in total 159 stations with a typical station distance of about 70 km, we obtain phase velocities for three subregions, which collectively cover most of Scandinavia (excluding southern Norway). The average phase dispersion curves are similar for all three subregions. They resemble the dispersion previously observed for the South Baltic craton and are about 1 per cent slower than the North Baltic shield phase velocities for periods between 40 and 80 s. However, a remarkable sin(1θ) phase velocity variation with azimuth is observed for periods &amp;gt;35 s with a 5 per cent deviation between the maximum and minimum velocities, more than the overall lateral variation in average velocity. Such a variation, which is incompatible with seismic anisotropy, occurs in northern Scandinavia and southern Norway/Sweden but not in the central study area. The maximum and minimum velocities were measured for backazimuths of 120° and 300°, respectively. These directions are perpendicular to a step in the lithosphere–asthenosphere boundary (LAB) inferred by previous studies in southern Norway/Sweden, suggesting a relation to large lithospheric heterogeneity. In order to test this hypothesis, we carried out 2-D full-waveform modeling of Rayleigh wave propagation in synthetic models which incorporate a steep gradient in the LAB in combination with a pronounced reduction in the shear velocity below the LAB. This setup reproduces the observations qualitatively, and results in higher phase velocities for propagation in the direction of shallowing LAB, and lower ones for propagation in the direction of deepening LAB, probably due to the interference of forward scattered and reflected surface wave energy with the fundamental mode. Therefore, the reduction in lithospheric thickness towards southern Norway in the south, and towards the Atlantic ocean in the north provide a plausible explanation for the observed azimuthal variations.

On-sky measurements of atmospheric dispersion – I. Method validation

ABSTRACT Observations with ground-based telescopes are affected by differential atmospheric dispersion due to the wavelength-dependent index of refraction of the atmosphere. The usage of an atmospheric dispersion corrector (ADC) is fundamental to compensate this effect. Atmospheric dispersion correction residuals above the level of ∼100 milliarcseconds (mas) will affect astronomical observations, in particular radial velocity and flux losses. The design of an ADC is based on atmospheric models. To the best of our knowledge, those models have never been tested on-sky. In this paper, we present a new method to measure the atmospheric dispersion on-sky in the optical range. We require an accuracy better than 50 mas that is equal to the difference between atmospheric models. The method is based on the use of cross-dispersion spectrographs to determine the position of the centroid of the spatial profile at each wavelength of each spectral order. The method is validated using cross-dispersed spectroscopic data acquired with the slit spectrograph UVES. We measure an instrumental dispersion of $\rm 47 ~ mas$ in the blue arm, and 15 and 23 mas in the two ranges of the red arm. We also measure a 4 per cent deviation in the pixel scale from the value cited in UVES manual. The accuracy of the method is ∼17 mas in the range of 315–665 nm. At this level, we can compare and characterize different atmospheric dispersion models for better future ADC designs.

Effects of Dark and Bright Timbral Instructions on the Production of Pitch and Timbre

The purpose of this study was to examine the effects of timbral instructions on pitch and timbre production. High school ( n = 28) and collegiate ( n = 28) trumpeters played sustained tones at two octave levels (written C4 and C5) following three types of timbral instructions (dark-timbre, bright-timbre, or neutral instructions). Presentation orders were randomly assigned. Dependent variables included one acoustical measure of pitch (absolute cent deviation) and one acoustical measure of timbre (spectral centroid). Participants also reported which type of instruction they perceived to result in their “best sound” and their “most in-tune performance.” Results indicated a significant interaction between timbral instruction condition and octave. Post hoc testing revealed that timbral instructions affected participants’ absolute cent deviation, but different effects were observed in each octave. The effect of timbral instructions on participants’ spectral centroid was nonsignificant. Participants demonstrated a preference for the neutral instruction over the dark- and bright-timbre instructions, and their tuning accuracy varied by octave and instruction condition. These data suggest that music educators may need to use timbral instructions judiciously so that the instruction to play with a different timbre does not result in unintentional changes in pitch.

Extraction kinetics, modelling and optimization of phenolic antioxidants from sweet potato peel vis-a-vis RSM, ANN-GA and application in functional noodles

The kinetic, modeling and optimised processing parameters for the extraction of phenolic antioxidant from an orange flesh sweet potato cultivar using an aqueous medium was studied. For the process to be effective; reaction time (t), temperature (T) and solid-to-solvent ratio (E) were optimised using the response surface methodology (RSM) and the artificial neural network (ANN) algorithms. Linear interaction between solid to solvent ratio was established to be most significant. Processing variables were established to make 30.44% (T), 38.75% (E) and 30.81% (t) roles to the efficiency of the system. Optimal parameters of 90 °C (T), 6.79% (E) and 60.5 min (t) were established as optimum processing variables using the RSM while ANN algorithm predicts optimal extraction conditions points of 98.64 °C (T), 11.68% (E) and 60.5 min (t). ANN algorithm was the best tool for optimum points prediction due to its low values of mean relative per cent deviation modulus and its absolute average deviation. Antioxidant properties of noodles improved with fortification with 1% peel extract. Optimization conditions and predictive models described in this studies offers an opportunity for the formulation of food products with functional properties by food processor.

Effects of Short-Term Practice With a Tonic Drone Accompaniment on Middle and High School Violin and Viola Intonation

The purpose of this study was to investigate the effect of tonic drone accompaniment on the intonation of violinists and violists. Twenty-eight middle and high school students performed an ascending diatonic line and a descending dominant 7th arpeggio on the violin or viola in three trials: pretest, posttest accompanied with drone, and posttest unaccompanied. The students were grouped based on age and years of experience. A significant difference in cent deviation scores was found between age groups but not years of experience. Post hoc analysis revealed a significant difference between the middle-age group and the youngest group. No significant difference was found overall between pretest, drone accompanied posttest, and unaccompanied posttest conditions.

Group contribution modeling of heat capacities in urethane-forming reactions

For a highly exothermic reaction, heat capacity is a critical determinant of temperature profile which impacts temperature-dependent variables such as reaction rate constants, heat of reaction, viscosity, and diffusivity. In the case of polymer-forming reactions: literally hundreds of oligomers can be present at any time, heat capacities are typically not available for most of these oligomeric monomers. The group contribution method emerges as one of the few viable approaches to make an estimate of heat capacities being a salient intermediate step toward the objective of simulating polyurethane reaction process. Based on compiled literature and supplemental DSC data, Missernard’s group contribution model was revised with alternative values to those suggested by literature and accessorial parameters for the following functional groups: a) isocyanate, b) six carbon sugar ring, c) aromatic benzene ring, and d) double-bonded oxygen of an ester to estimate heat capacities from 25 °C to 120 °C for alcohols and isocyanate present in the urethane-forming reactions. Modeling performance showed a good agreement with an overall 1.59 per cent deviation. It was also observed that the alcohol heat capacity generally decreased with the rise of molecular weight.

The effect of repeated attempts and test-retest reliability in children’s singing accuracy

The purpose of this study was to examine the effect of repeated attempts at singing accuracy tasks. Test-retest reliability of singing accuracy was examined in a second administration of the test. A secondary purpose was to analyze individual variability in children’s singing accuracy. Test stimuli were designed using five attempts each at a single pitch, interval, and four-note pattern, and song singing. Children aged 6–11 were given the one-on-one singing accuracy test, and an identical form of the test was administered again within 1–6 weeks. Pitch matching items were scored by measuring the deviation in Hertz from the stimuli. The song singing item was scored by singing teachers using an 8-point scale with acceptable inter-rater reliability ( r = .86). Participants’ individual best attempt out of five was equally distributed, with overall performance increasing across subsequent attempts measured in signed cent deviation. A repeated-measures ANOVA with the task type (single, interval, and pattern) and attempt (1, 2, 3, 4, and 5) as the within-subjects variables indicated no main effect for task type ( p = .129), but a significant main effect for attempt ( p &lt; .001, [Formula: see text] = .087). Test-retest reliability was considered high ( r = .69).

Climatological study on maximum temperature trends and heat waves at Ludhiana

The temperature is the most important climatic factor that influences growth, development and yield of crops. During the summer season the maximum temperature in Punjab reaches upto 44–45oC during April or May months and affecting the kharif crops in the region. Forty three years data (1970–2012) on maximum temperature of Ludhiana, located in the central plain region of Punjab state at an altitude of 247 m above msl for the month of April to June was collected and classified into various groups for interpretation. Results showed that the lowest and the highest maximum temperature recorded during the study period were 19.4 and 47.2°C for the months of April and May, respectively during different years. The Coefficient of Variation varied from 35–46 per cent and standard deviation of average temperatures varies from 3.2 to 3.6°C. Persistence in maximum temperature for five days was found to be minimum 36.2 to 46.2 per cent. Analysis indicated that maximum number of heat waves occurred during the month of June. A negative and linear relationship has been observed between rice yield and maximum temperature of different months but results indicated that maximum temperature has not much affect on rice yield during the period under study. The decade wise analysis of extreme temperature analysis showed that maximum number of extreme events occurred during the last decade (2000–2012) and it was also found that maximum number of extreme temperatures occurred during the month of May in all the categories of temperatures at Ludhiana.

Measuring solubility of carbon dioxide in aqueous blends of N-methyldiethanolamine and 2-((2-aminoethyl)amino)ethanol at low CO2 loadings and modelling by electrolyte SAFT-HR EoS

In this work, new solubility values for CO2 absorption in aqueous solutions of N-methyldiethanolamine (MDEA) in the presence of different mole ratios of 2-((2-aminoethyl)amino)ethanol (AEEA) at low pressures are obtained. The total molar amine concentration of all the solutions has been fixed equal to 3.360mol·L−1 (5.370mol amine·kg−1 water). The mole ratio of AEEA/MDEA was set to 0.12500, 0.10000 and 0.05000. The experimental total pressure varied from (7.3 to 386.6)kPa and the experimental temperature was set to (313.15, 328.15, 343.15 and 358.15)K. The electrolyte SAFT-HR (eSAFT-HR) equation of state (EoS) (Najafloo et al., 2014) has been successfully applied to model the solubility of CO2 in aqueous mixtures of AEEA and MDEA. The overall average absolute relative per cent deviation (AAD%) in calculating the total pressure as a function of CO2 loading is 7.74 for (AEEA+MDEA+CO2+H2O) quaternary system at the four values of temperature. To verify the predictive ability of the model, the eSAFT-HR EoS was extrapolated to the Zoghi and Feyzi (2013) solubility results of the same quaternary system that were obtained at higher pressures or higher CO2 loadings at the same temperatures. The AAD of the present model is 11.39% lower.

Influence of firing process quality on dielectric constant of microwave LTCC substrates

Purpose – The purpose of this paper was to investigate the influence of non-uniform temperature distribution inside a box furnace during the firing process on electrical properties of the low-temperature co-fired ceramic (LTCC) materials used in radio frequency (RF)/microwave applications. Design/methodology/approach – The authors studied the change in dielectric constant of two popular LTCC materials (DP 951 and DP 9K7) depending on the position of their samples inside the box furnace. Before firing of the samples, temperature distribution inside the box furnace was determined. The dielectric constant was measured using the method of two microstrip lines. Findings – The findings showed that non-uniform temperature distribution with spatial difference of 6°C can result in 3-4 per cent change of the dielectric constant. It was also found that dielectric constant of the two tested materials shows disparate behavior under the same temperature distribution inside the box furnace. Practical implications – The dielectric constant of the substrate materials is crucial for RF/microwave applications. Therefore, it was shown that 3-4 per cent deviation in dielectric constant can result in considerable detuning of microwave circuits and antennas. Originality/value – To the best of the authors’ knowledge, the quantitative description of the impact of temperature distribution inside a box furnace on electrical properties of the LTCC materials has never been published in the open literature. The findings should be helpful when optimizing production process for high yield of reliable LTCC components like filters, baluns and chip antennas.

Waist to height ratio for recording the risks of overweight in schoolchildren in Kerala

The prevalence of overweight/obesity among 6000 children at 7-12 years was monitored using the established methodologies. Prevalence rates obtained using percentiles were proximate to that using waist-to-height ratio (WHTR) 0.50 and were on par with the reported rates. The prevalence were worked out with WHTR values from 0.45 to 0.53 and compared with percentiles. The minimum per cent deviation of 5.4 was observed at WHTR of 0.48 (against 6.4% at WHTR 0.50) and further the deviation at this point was distributed near-uniformly (2.6% above and 2.8% below the WHTR), suggesting that this is the optimum cut-off point for children in this region. ROC analysis against percentiles has given a higher sensitivity of 0.630 at WHTR 0.48 in this region and area under ROC curve was 0.827 at WHTR 0.48.

Prediction of the CEC to clay ratio using mid-infrared spectroscopy

The ratio of cation exchange capacity to clay (CCR) has been used as an index of clay mineralogy in subsoils low in organic matter in place of the standard X-ray diffraction measurement. Laboratory determination of this ratio is time-consuming and expensive and involves two analyses. In this paper, the CCR has been successfully predicted from mid-infrared diffuse reflectance spectra using partial least-squares regression (PLSR) with a square-root transformation of the CCR values (R2 = 0.860; root mean squared error of prediction = 0.089; relative per cent deviation = 2.660 for an independent validation set). The most important wavelengths used in the PLSR calibration were identified. The prediction of CCR using mid-infrared spectroscopy provides a cheaper and faster alternative to laboratory determination.