Cobalt availability in the soil plant and animal food chain: a study under a peri-urban environment

Cobalt metal is considered as an essential trace element for the animals. Present investigation was undertaken in the peri-urban area to analyze the cobalt availability in animal food chain by using different indices. Cow, buffalo and sheep samples along with forage and soil samples were collected from the three different sites of District Jhang and analyzed through atomic absorption spectrophotometer. Cobalt values differed in soil samples as 0.315-0.535 mg/kg, forages as 0.127-0.333 mg/kg and animal samples as 0.364-0.504 mg/kg. Analyzed cobalt concentration in soil, forage and animal samples was found to be deficient in concentration with respect to standard limits. Soil showed the minimum cobalt level in Z. mays while maximum concentration was examined in the forage C. decidua samples. All indices examined in this study has values lesser than 1, representing the safer limits of the cobalt concentration in these samples. Enrichment factor (0.071-0.161 mg/kg) showed the highly deficient amount of cobalt enrichment in this area. Bio-concentration factor (0.392-0.883) and pollution load index (0.035-0.059 mg/kg) values were also lesser than 1 explains that plant and soil samples are not contaminated with cobalt metal. The daily intake and health risk index ranged from 0.00019-0.00064 mg/kg/day and 0.0044-0.0150 mg/kg/day respectively. Among the animals, cobalt availability was maximum (0.0150 mg/kg/day) in the buffaloes that grazed on the C. decidua fodder. Results of this study concluded that cobalt containing fertilizers must be applied on the soil and forages. Animal feed derived from the cobalt containing supplements are supplied to the animals, to fulfill the nutritional requirements of livestock.

Hydrogen sulphide and nitric oxide mitigate the negative impacts of waterlogging stress on wheat (Triticum aestivum L.)

Nitric oxide (NO) and hydrogen sulphide (H₂ S) are important gaseous signalling molecules that regulate key physiochemical mechanisms of plants under environmental stresses. A number of attempts have been made to improve waterlogging tolerance in plants, but with limited success. Having said that, NO and H₂ S are vital signalling molecules, but their role in mitigating waterlogging effects on crop plants is not well established. We investigated the efficacy of exogenous NO and H₂ S to alleviate waterlogging effects in two wheat cultivars (Galaxy-2013 and FSD-2008). Waterlogging produced a noticeable reduction in plant growth, yield, chlorophyll, soluble sugars and free amino acids. Besides, waterlogging induced severe oxidative damage seen as higher cellular TBARS and H₂ O₂ content. Antioxidant enzyme activity increased together with a notable rise in Fe²⁺ and Mn²⁺ content. Proline content was higher in waterlogged plants compared with non-waterlogged plants. In contrast, waterlogging caused a substantial decline in endogenous levels of essential nutrients (K⁺ , Ca²⁺ and Mg²⁺ ). Waterlogged conditions led to Fe²⁺ and Mn²⁺ toxicity due to rapid reduction of Fe³⁺ and Mn³⁺ in the soil. Exogenous NO and H₂ S significantly protected plants from waterlogging effects by enhancing the oxidative defence and regulating nutritional status. Besides, the protective effects of exogenous NO were more prominent as compared with effects of H₂ S. Further, we did not study the effect of H₂ S and NO on photosynthetic attributes and expression of stress-related genes. Therefore, future studies should examine the effects of H₂ S and NO on wheat physiology and gene expression under waterlogging.

The level of allergens in dust samples collected from selected schools in Shiraz, Iran and its asthma-risk implications

BACKGROUND

Both home and school are important places where children are exposed to various indoor allergens. This study aimed to identify the profile of indoor allergens in schools and its impact on asthma development.

METHODS

A total of 104 classrooms from 52 schools were selected for dust collection during the fall of 2017. The levels of indoor allergens including dust mite (Der f1, Der p1), cat (Fel d1), cockroach (Bla g1) and mouse (Mus m1) were measured by enzyme linked immunosorbent assay (ELISA). The diagnosis of asthma was made in all students of the selected classes by the allergist. The collected data were analyzed using SPSS version 21.0.

RESULTS

Out of 2816 students in the selected classes, 180 students were involved with asthma. Students were mostly exposed to Bla g1 (83.1%), followed by Der f1 (51.5%), Mus m 1 (45.5%), Der p1 (8.9%) and Fel d1 (7.9%) in the dust collected from 101 classrooms. Although levels of all studied allergens in the settled dust of the classrooms were low, there was a relationship between Fel d1 in the classroom dust and development of asthma.

CONCLUSION

This study showed considerable levels of cockroach allergens in schools. Exposure to cat allergen in our schools played an important role in asthma development; further school-based investigations require evaluating the role of classroom allergen on asthma development.

Artificial neural network model to predict transport parameters of reactive solutes from basic soil properties

Measurement of solute-transport parameters through soils for a wide range of solute- and soil-types is time-consuming, laborious, expensive and practically impossible. So, indirect methods for estimating the transport parameters by pedo-transfer functions are now advancing. This study developed and evaluated an Artificial Neural Network (ANN) model for estimating the transport velocity (V), dispersion coefficient (D) and retardation factor (R) of NaAsO₂, Pb(NO₃)₂, Cd(NO₃)₂, C₉H₉N₃O₂ and CaCl₂ from the basic soil properties. Breakthrough data of the solutes were measured in 14 agricultural soils of Bangladesh by time-domain reflectometry (TDR) in repacked soil columns under unsaturated steady-state water-flow conditions. The transport parameters of the chemicals were determined by analyzing the solute breakthrough data. Bulk density (γ), organic carbon (OC), clay (C) content, pH, median grain diameter (D₅₀) and uniformity coefficient (C_u) of the soils were determined. An ANN model for V, D and R was developed by using data of eight soils, validated/tested with the data of five soils and verified with the data of one soil. Clay content and bulk density of the soils were the most sensitive input variables to the ANN model followed by other soil properties (OC, C, pH, D₅₀ and C_u). The model reliably predicted V, D and R with relative root-mean-square error (RRMSE) of 0.028-0.363, mean error (ME) of - 0.00004 to 0.0005, bias error (BOE%) of 0-0.003 and modeling efficiency (EF) of >0.99. Thus, the ANN model can significantly enhance prediction of pollution transport through soils in terms of cost and effort.

Recent Progress for the Utilization of Curcuma longa, Piper nigrum and Phoenix dactylifera Seeds against Type 2 Diabetes

Background

Diabetes mellitus is an important human disease afflicting many from various walks of life in different countries. Even though modern medicines contribute a variety of effective treatment options, they can have several unfavourable effects. The intention of this review is to organize and discuss various studies that have been previously conducted on the effectiveness of these herbal plants in diabetes.

Method

By using various electronic search databases, a comprehensive English literature search was conducted. Different search terms were used by combining all the search fields in titles, abstracts and keywords.

Results

Curcuma longa,a spice, is commonly known as turmeric and belongs to the family Zingiberaceae. Piper nigrumis also a spice, commonly called black pepper, and belongs to the family Piperaceae. Phoenix dactylifera, commonly known as date fruit, belongs to the family Arecaceae. From ancient times, they have been traditionally used for the treatment of various diseases. Among various activities, regulation of hyperglycaemia is considered one of their important effects. One of the aetiological factors implicated in the development of diabetes and its complications is the damage induced by free radicals. Antioxidant properties of antidiabetic compounds would be more beneficial. Extracts of these plants have shown hypoglycaemic and hypolipidaemic effects by the involvement of several mechanisms. In the future, further studies are needed to investigate the mechanisms involved in their hypoglycaemic potential and their active constituents as synthetic analogues.

Conclusions

This review focusses on some medicinal plants that have antidiabetic effect, thus contributing to the reduction of risk factors associated with diabetes, and related beneficial effects are compiled.

Exogenously applied selenium reduces oxidative stress and induces heat tolerance in spring wheat

Heat stress (HS) is a worldwide threat to productivity of wheat, especially in arid and semiarid regions of the world. Earlier studies suggested the beneficial effects of selenium (Se) on the growth of some crop species grown under stressful environments. In the present study, we assessed whether Se application could increase antioxidative potential, and thus enhance tolerance to heat in wheat at the sensitive stage i.e., heading stage. At the heading stage, after foliar application of sodium selenate solutions (0, 2 and 4 mg Se L(-1)), the plants of wheat cultivars, namely Chakwal-97 (drought tolerant) and Faisalabad-08 (drought sensitive), were subjected to HS (38 ± 2 °C). The HS significantly altered antioxidative potential, affected growth, photosynthetic pigments and grain yield in both cultivars. Exogenous application of low (2 mg L(-1)) Se increased chlorophyll a and total chlorophyll contents and modulated the growth of wheat plants under HS. However, high concentration (4 mg L(-1)) of Se was much more effective in increasing grains per spike and grain yield in heat stressed plants of both wheat cultivars. Exogenous Se increased both enzymatic (catalase and ascorbate peroxidase activities) and non-enzymatic (carotenoids, anthocyanins and ascorbic acid contents) antioxidants while decreased oxidants (hydrogen peroxide and malondialdehyde contents) under HS in both wheat cultivars. In conclusion, foliar application of Se (4 mg L(-1)) was much more effective in mitigating the deleterious effects of HS on grain yield of wheat plants. The results suggested that Se-mediated up-regulation of antioxidative system (both enzymatic and non-enzymatic) helped the wheat plants to increase fertility, and hence avoid reduction of grain yield under HS.

Prevalence and presentation of chronic venous disease in Pakistan: a multicentre study

Our objective was to study the prevalence and clinical pattern of chronic venous disease (CVD) in the Pakistani population. This was a multicentre cross-sectional study in which 100 primary care physicians examined 3000 subjects. The study population was aged 18–95 years (mean ± SD = 39 ± 13.2) comprised 47.4% women and 52.6% men. The prevalence of CVD was 34.8%, being significantly higher ( P < 0.04) among men (36.4%) than women (33.0%). The maximum prevalence was of C3 (36.7%), followed by C2 (15.8%). The most frequent symptom was pain in the legs (59.2%) followed by heavy legs (42.7%) and night cramps (34.4%). The prevalence of symptoms increased with age but was similarly distributed between men and women. Family history of CVD, blood clots in veins and lack of exercise were significant risk factors. The roles of age or gender as risk factors could not be established. In conclusion, the prevalence and presentation of CVD in Pakistan is similar to most other countries.

Chemical speciation and potential mobility of heavy metals in the soil of former tin mining catchment

This study describes the chemical speciation of Pb, Zn, Cu, Cr, As, and Sn in soil of former tin mining catchment. Total five sites were selected for sampling and subsequent subsamples were collected from each site in order to create a composite sample for analysis. Samples were analysed by the sequential extraction procedure using optical emission spectrometry (ICP OES). Small amounts of Cu, Cr, and As retrieved from the exchangeable phase, the ready available for biogeochemical cycles in the ecosystem. Low quantities of Cu and As could be taken up by plants in these kind of acidic soils. Zn not detected in the bioavailable forms while Pb is only present in negligible amounts in very few samples. The absence of mobile forms of Pb eliminates the toxic risk both in the trophic chain and its migration downwards the soil profile. The results also indicate that most of the metals have high abundance in residual fraction indicating lithogenic origin and low bioavailability of the metals in the studied soil. The average potential mobility for the metals giving the following order: Sn > Cu > Zn > Pb > Cr > As.

Biomimetic ligands for transition metals: catechol-containing peptides

The tetrapeptide ligands 6a and 6b containing a catechol moiety have been synthesised and their metal binding with Fe(III), Mn(III) and Cu(II) has been studied using fluorescence spectroscopy.