Diffuse reflectance spectroscopy and digital soil mapping for assessing soil-associated off-road vehicle mobility risk.

Soil attributes such as granulometric fractions and Atterberg limits (LL: liquid limit, PL: plastic limit, and PI: plasticity index) are needed to assess off-road vehicle mobility (OVM) risks. Parameters describing these attributes are generally measured in soil samples collected from a few locations through cumbersome laboratory methods. Although diffuse reflectance spectroscopy (DRS) can rapidly yield estimates for soil attributes in samples collected from specific locations and digital soil mapping (DSM) can transform such discrete measurements into spatially-continuous inference systems, these two technologies are rarely used for assessing OVM risks. In this study, we combined the DRS and DSM approaches for deriving spatially-continuous estimates for the key vehicle mobility parameters (gravel, sand, and fine particles; Cu: coefficients of uniformity; Cc: coefficient of curvature; LL; and PI) and classified soils using the Unified Soil Classification System (USCS). A total of 204 soil samples were collected from the north-eastern Himalayan state of Sikkim for measuring these parameters along with spectral reflectance over the visible and near-infrared region. Results of the chemometric models in the DRS approach showed that the USCS parameters may be estimated with the coefficient of determination (R2) values as high as 0.72. The fine (<2 mm diameter) fraction spectra provided the best estimates for the Atterberg limits while a combination of spectra collected from fine and coarse (>2 mm diameter) fractions was effective in estimating other granulometric fractions except for sand, which was best estimated using the coarse fraction spectra. With the DSM approach allowing effective mapping of these parameters, a spatially-continuous framework to quantify soil-associated OVM risks was developed for Sikkim for the first time.

Living with arsenic in the environment: An examination of current awareness of farmers in the Bengal basin using hybrid feature selection and machine learning.

High levels of arsenic in drinking water and food materials continue to pose a global health challenge. Over 127 million people alone in Bangladesh (BD) and West Bengal (WB) state of India are exposed to elevated levels of arsenic in drinking water. Despite decades of research and outreach, arsenic awareness in communities continue to be low. Specifically, very few studies reported arsenic awareness among low-income farming communities. A comprehensive approach to assess arsenic awareness is a key step in identifying research and development priorities so that appropriate stakeholder engagement may be designed to tackle arsenic menace. In this study, we developed a comprehensive arsenic awareness index (CAAI) and identified key awareness drivers (KADs) of arsenic to help evaluate farmers' preferences in dealing with arsenic in the environment. The CAAI and KADs were developed using a questionnaire survey in conjunction with ten machine learning (ML) models coupled with a hybrid feature selection approach. Two questionnaire surveys comprising of 73 questions covering health, water and community, and food were conducted in arsenic-affected areas of WB and BD. Comparison of CAAIs showed that the BD farmers were generally more arsenic-aware (CAAI = 7.7) than WB farmers (CAAI = 6.8). Interestingly, the reverse was true for the awareness linked to arsenic in the food chain. Application of hybrid feature selection identified 15 KADs, which included factors related to stakeholder interventions and cropping practices instead of commonly perceived factors such as age, gender and income. Among ML algorithms, classification and regression trees and single C5.0 tree could estimate CAAIs with an average accuracy of 84%. Both communities agreed on policy changes on water testing and clean water supply. The CAAI and KADs combination revealed a contrasting arsenic awareness between the two farming communities, albeit their cultural similarities. Specifically, our study shows the need for increasing awareness of risks through the food chain in BD, whereas awareness campaigns should be strengthened to raise overall awareness in WB possibly through media channels as deemed effective in BD.

Spatial structure, parameter nonlinearity, and intelligent algorithms in constructing pedotransfer functions from large-scale soil legacy data.

Pedotransfer function (PTF) approach is a convenient way for estimating difficult-to-measure soil properties from basic soil data. Typically, PTFs are developed using a large number of samples collected from small (regional) areas for training and testing a predictive model. National soil legacy databases offer an opportunity to provide soil data for developing PTFs although legacy data are sparsely distributed covering large areas. Here, we examined the Indian soil legacy (ISL) database to select a comprehensive training dataset for estimating cation exchange capacity (CEC) as a test case in the PTF approach. Geostatistical and correlation analyses showed that legacy data entail diverse spatial and correlation structure needed in building robust PTFs. Through non-linear correlation measures and intelligent predictive algorithms, we developed a methodology to extract an efficient training dataset from the ISL data for estimating CEC with high prediction accuracy. The selected training data had comparable spatial variation and nonlinearity in parameters for training and test datasets. Thus, we identified specific indicators for constructing robust PTFs from legacy data. Our results open a new avenue to use large volume of existing soil legacy data for developing region-specific PTFs without the need for collecting new soil data.

Risk of Adverse Pregnancy Outcomes among Women Practicing Poor Sanitation in Rural India: A Population-Based Prospective Cohort Study.

BACKGROUND: The importance of maternal sanitation behaviour during pregnancy for birth outcomes remains unclear. Poor sanitation practices can promote infection and induce stress during pregnancy and may contribute to adverse pregnancy outcomes (APOs). We aimed to assess whether poor sanitation practices were associated with increased risk of APOs such as preterm birth and low birth weight in a population-based study in rural India. METHODS AND FINDINGS: A prospective cohort of pregnant women (n = 670) in their first trimester of pregnancy was enrolled and followed until birth. Socio-demographic, clinical, and anthropometric factors, along with access to toilets and sanitation practices, were recorded at enrolment (12th week of gestation). A trained community health volunteer conducted home visits to ensure retention in the study and learn about study outcomes during the course of pregnancy. Unadjusted odds ratios (ORs) and adjusted odds ratios (AORs) and 95% confidence intervals for APOs were estimated by logistic regression models. Of the 667 women who were retained at the end of the study, 58.2% practiced open defecation and 25.7% experienced APOs, including 130 (19.4%) preterm births, 95 (14.2%) births with low birth weight, 11 (1.7%) spontaneous abortions, and six (0.9%) stillbirths. Unadjusted ORs for APOs (OR: 2.53; 95% CI: 1.72-3.71), preterm birth (OR: 2.36; 95% CI: 1.54-3.62), and low birth weight (OR: 2.00; 95% CI: 1.24-3.23) were found to be significantly associated with open defecation practices. After adjustment for potential confounders such as maternal socio-demographic and clinical factors, open defecation was still significantly associated with increased odds of APOs (AOR: 2.38; 95% CI: 1.49-3.80) and preterm birth (AOR: 2.22; 95% CI: 1.29-3.79) but not low birth weight (AOR: 1.61; 95% CI: 0.94-2.73). The association between APOs and open defecation was independent of poverty and caste. Even though we accounted for several key confounding factors in our estimates, the possibility of residual confounding should not be ruled out. We did not identify specific exposure pathways that led to the outcomes. CONCLUSIONS: This study provides the first evidence, to our knowledge, that poor sanitation is associated with a higher risk of APOs. Additional studies are required to elucidate the socio-behavioural and/or biological basis of this association so that appropriate targeted interventions might be designed to support improved birth outcomes in vulnerable populations. While it is intuitive to expect that caste and poverty are associated with poor sanitation practice driving APOs, and we cannot rule out additional confounders, our results demonstrate that the association of poor sanitation practices (open defecation) with these outcomes is independent of poverty. Our results support the need to assess the mechanisms, both biological and behavioural, by which limited access to improved sanitation leads to APOs.

Rapid estimation of compost enzymatic activity by spectral analysis method combined with machine learning.

The aim of this study was to investigate the feasibility of using visible near-infrared (VisNIR) diffuse reflectance spectroscopy (DRS) as an easy, inexpensive, and rapid method to predict compost enzymatic activity, which traditionally measured by fluorescein diacetate hydrolysis (FDA-HR) assay. Compost samples representative of five different compost facilities were scanned by DRS, and the raw reflectance spectra were preprocessed using seven spectral transformations for predicting compost FDA-HR with six multivariate algorithms. Although principal component analysis for all spectral pretreatments satisfactorily identified the clusters by compost types, it could not separate different FDA contents. Furthermore, the artificial neural network multilayer perceptron (residual prediction deviation=3.2, validation r(2)=0.91 and RMSE=13.38 µg g(-1) h(-1)) outperformed other multivariate models to capture the highly non-linear relationships between compost enzymatic activity and VisNIR reflectance spectra after Savitzky-Golay first derivative pretreatment. This work demonstrates the efficiency of VisNIR DRS for predicting compost enzymatic as well as microbial activity.

Low dose hydroxyurea is effective in reducing the incidence of painful crisis and frequency of blood transfusion in sickle cell anemia patients from eastern India.

There are several questions pertaining to dosage, duration and potential long-term toxicity of hydroxyurea (HU) therapy. Use of HU is extremely limited in eastern India because of its high cost and apprehension of its toxicities. We undertook this study to assess the clinical, biochemical and hematological efficacy of minimal dose HU (10 mg/kg/day) in 118 sickle cell anemia patients (27 pediatric and 91 adults). The frequency of painful crises reduced significantly in 71.5 and 92.2% in pediatric and adult cases, respectively. Ninety-five percent of the patients became transfusion independent. The baseline Hb F, total hemoglobin (Hb), MCV, MCH and MCHC levels increased significantly, whereas the WBC, platelet count and total serum bilirubin values decreased significantly. This is the first study of minimal dose HU therapy in eastern India that showed impressive improvement in clinical and hematological parameters with minimal toxicity.

ß-globin gene haplotypes linked with the Hb D-Punjab [ß121(GH4)Glu→Gln, GAA>CAA] mutation in eastern India.

Hb D-Punjab [ß121(GH4)Glu→Gln] is prevalent in the northern states of the Indian subcontinent. Due to inadequate data from Asian countries, the origin and spread of the Hb D-Punjab mutation are uncertain. In a study of sickle cell hemoglobinopathies, we detected the Hb D-Punjab mutation in 25 subjects from 11 unrelated Agharia families. Twelve cases were Hb S [ß6(A3)Glu→Val]/Hb D-Punjab compound heterozygotes and 13 were Hb D trait carriers. In 76.0% of the cases, the ß(D) gene was linked to haplotype I, whereas 24.0% had a novel haplotype. None of the haplotypes matched the ß(A) haplotype of the local population. In view of the ancestral origin of the subjects and the high prevalence of the ß(D) gene in the states of northern India, we suggest a North Indian origin for the ß(D) mutation in our population. The finding of a novel haplotype in eastern India supports the hypothesis of a multicentric origin of this mutation.

Pfcrt haplotypes and in-vivo chloroquine response in Sundergarh district, Orissa, India.

The Plasmodium falciparum chloroquine resistance transporter (Pfcrt) K76T mutation and haplotype (amino acids 72-76) were analyzed as markers of chloroquine (CQ) resistance in the blood samples of patients from two sites of different intensities of malaria transmission (high, n=70; low, n=68) in Sundergarh district of Orissa, India and correlated with the in-vivo response. Early treatment failure (ETF) was significantly more frequent in the high endemic area (32.9 vs. 7.4%, P<0.001), with children below 5 years suffering more. A high frequency of pfcrt K76T mutation was observed in both the areas (87.1 vs. 79.4%, P=0.22). Patients carrying pfcrt 76T were the most likely to develop ETF (odds ratio 36; 95% CI 3.35-1653.3; P<0.001). The ratio of 76T:K76 was 22:9 and 11:14, respectively, in high and low endemic areas (odds ratio 3.1; 95% CI 0.9-11.03; P=0.04), which may be used as a measure of drug pressure. Sequences of pfcrt codons 72-76 showed 16 of the CQ-resistant haplotypes to be SVMNT, 5 CVMNT and 12 CVIET. The CQ-sensitive haplotypes were mostly CVMNK in 10 samples; CVIEK in 2 samples. Both Southeast Asian and South American haplotypes were present, with the latter predominating.

Dual-domain solute transfer and transport processes: evaluation in batch and transport experiments.

Soil macropore networks establish a dual-domain transport scenario in which water and solutes are preferentially channeled through soil macropores while slowly diffusing into and out of the bulk soil matrix. The influence of macropore networks on intra-ped solute diffusion and preferential transport in a soil typical of subsurface-drained croplands in the Midwestern United States was studied in batch- and column-scale experiments. In the batch diffusion studies with soil aggregates, the estimated diffusion radius (length) of the soil aggregates corresponded to the half-spacing of the aggregate fissures, suggesting that the intra-ped fissures reduced the diffusion impedance and preferentially allowed solutes to diffuse into the soil matrix. In the column-scale solute transport experiments, the average diffusion radius (estimated from HYDRUS-2D simulations and a first-order diffusive transfer term) was nearly double that of the batch-scale study. This increase may be attributed to a loss of pore continuity and a compounding of the small diffusion impedance through macropores at the larger scale. The column-scale solute transport experiments also suggest that two preferential networks exist in the soil. At and near soil saturation, a primary network of large macropores (possibly root channels and earthworm burrows) dominate advective transport, causing a high degree of physical and sorption nonequilibrium and simultaneous breakthrough of a nonreactive (bromide) and a reactive (alachlor) solute. As the saturation level decreases, the primary network drains, while transport through smaller macropores (possibly intra-ped features) continues, resulting in a reduced degree of nonequilibrium and separation in the breakthrough curves of bromide and alachlor.

Epidemiology of malaria transmission and development of natural immunity in a malaria-endemic village, San Dulakudar, in Orissa state, India.

We describe the epidemiology of malaria in San Dulakudar, a village in Sundargarh District in the state of Orissa in eastern India. Malaria transmission is perennial with Plasmodium falciparum, accounting for greater than 80% of malaria cases. Transmission intensity varies with season with high transmission after the monsoon rains in autumn and winter, low transmission in summer, and intermediate transmission in spring. The anthropophagic mosquito Anopheles fluviatilis was identified as the main vector for malaria transmission. Based on observations of spleen rates and supported by data on malaria parasite prevalence and malaria incidence, San Dulakudar can be classified as a hyperendemic area for P. falciparum malaria. Parasite prevalence and malaria incidence rates decrease with age, suggesting that residents of San Dulakudar develop immunity to malaria. The study demonstrates the presence of regions in the Indian subcontinent such as Sundargarh District where P. falciparum is the primary cause of malaria and where malaria transmission rates are comparable to those found in many parts of Africa.

Effect of iron supplementation on mild to moderate anaemia in pulmonary tuberculosis.

Anaemia is a common complication of pulmonary tuberculosis. The precise mechanism of anaemia in pulmonary tuberculosis is not clearly known, but anaemia of inflammation as well as of Fe deficiency has been implicated. Both are common in developing countries. It is extremely difficult to distinguish anaemia of Fe deficiency from anaemia of inflammation with the haematological indices used routinely. Therefore, Fe preparations are usually prescribed for all anaemic patients irrespective of the aetiology. This approach has been questioned. The present study aimed to assess the effect of Fe supplementation on anaemic patients with pulmonary tuberculosis. Adult male patients 15-60 years of age with pulmonary tuberculosis and a blood haemoglobin concentration 80-110 g/l were included in the study; healthy adult males matched for age and socio-economic status were taken as controls. Blood haemoglobin concentration, total erythrocyte count (TEC), packed cell volume (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin and serum Fe, total Fe-binding capacity and ferritin were estimated before treatment and 1, 2 and 6 months after treatment. The patients were divided randomly into three groups and during the initial 2 months of treatment were provided with one of three supplementary regimens consisting of placebo, Fe alone or Fe with other haematinics. Significant improvements in haematological indices and Fe status were noticed in all three groups. Blood haemoglobin concentration, MCV and PCV were significantly higher at 1 month in both Fe-supplemented groups than the placebo group. This difference, however, disappeared at 2 and 6 months with similar values in all three groups. The increase of other haematological indices was similar in all groups. Serum Fe and Fe saturation of transferrin were significantly higher in both Fe-supplemented groups than the placebo group up to 2 months; this effect, however, disappeared at 6 months. There was a consistent increase in TEC and decrease in ferritin values up to 6 months in all groups. Radiological and clinical improvement was similar in all three groups. These observations suggest that Fe supplementation in mild to moderate anaemia associated with pulmonary tuberculosis accelerated the normal resumption of haematopoiesis in the initial phases by increasing Fe saturation of transferrin. However, consistent improvement of haematological status was dependent only on the improvement of the disease process.

Complications and mortality patterns due to Plasmodium falciparum malaria in hospitalized adults and children, Rourkela, Orissa, India.

Of 1857 Plasmodium falciparum malaria patients hospitalized from 1995 to 1998, 608 had severe malaria and 83 died. Acute renal failure, jaundice and respiratory distress were common in adults whereas children frequently had severe anaemia. Cerebral malaria occurred equally in adults and children but recovery from coma was quicker in children. Multiple complications caused high mortality in adults.

Plasmodium falciparum infection elicits both variant-specific and cross-reactive antibodies against variant surface antigens.

Naturally acquired antibodies to Plasmodium falciparum erythrocyte membrane protein-1 (PfEMP-1), the variant surface antigens expressed on the surface of infected erythrocytes, are thought to play a role in protection against P. falciparum malaria. Here, we have studied the development of antibodies to PfEMP-1 in adult malaria patients living in Rourkela, India, an area with a low malaria transmission rate, and prevalence of antibodies to PfEMP-1 in residents of San Dulakudar, India, a village in which P. falciparum malaria is hyperendemic. Convalescent-phase sera from adult malaria patients from Rourkela agglutinate homologous P. falciparum isolates as well as some heterologous isolates, suggesting that they develop partially cross-reactive antibodies to PfEMP-1 following infection. Adult sera from San Dulakudar agglutinate diverse P. falciparum isolates, suggesting that they have antibodies with wide recognition of diverse PfEMP-1. Mixed-agglutination assays using pairs of P. falciparum isolates confirm the presence of both variant-specific and partially cross-reactive antibodies in convalescent-phase sera from Rourkela and adult sera from San Dulakudar. Analysis of PfEMP-1 sequences suggests a molecular basis for the observed cross-reactivity.