Heavy Metals Accumulation by Indigenous Plants Growing in Contaminated Soil in a Gold Mining Area in Ghana

Phytoremediation is an environmentally friendly, low cost biotechnological process that is fast gaining prominence in the cleaning of contaminated soils in the tropics. The accumulative potential of indigenous or native plants for heavy metals in mine tailings at the Storage Facility of the Chirano Gold Mine Limited, Ghana was investigated. Plant species were sampled in five plots, each 32 m2. Samples of plants were harvested and separated into roots and shoots and the corresponding rhizospheric soil samples collected. They were analysed for the total concentrations of heavy metals; Arsenic (As), Cadmium (Cd) and Zinc (Zn) using Atomic Absorption Spectrophotometer. Bioavailable fractions of studied metals in the soil samples were determined with the formation of metal complex with Ethylenediaminetetraacetic acid and ammonium acetate reagents. The hyper-accumulation potential and mobility of heavy metals within the plants were determined from the bioaccumulation and translocation factors. Differences in mean concentrations of heavy metals in the plants (shoot, root and whole) were separated using Tukey B Analysis of Variance, SPSS version 20, at significant level of p < 0.05. The mean concentrations of total and bioavailable As, Cd, and Zn in the soil samples varied with Zinc being most predominant (13.20 mg/kg). However, As was the most available with 39% bioavailability. The soil elemental concentrations of As (3.0 mg/kg), Cd (0.29 mg/kg) and Zn (13.20 mg/kg) were below the WHO recommended standards of 12 mg/kg, 1.4 mg/kg and 200 mg/kg for As, Cd and Zn respectively. The concentrations of all metals in the plant organs varied between species. In all plant species Zinc was the most accumulated heavy metal, recording the highest level of accumulation (135.76 mg/kg) in the root of Euphorbia heterophylla. Bioaccumulation factor as expressed by total and bioavailable metal concentrations in soil indicate that all the plant species demonstrate good hyperaccumulation and phytostabilisation potential for Zn and Cd whilst 13 and 8 plant species demonstrate good phytoextraction potential for As. The translocation factor indicate that 8 plant species are good phytostabilisers for Zn, 7 plant species for Cd and 10 plant species for As. The accumulative and phytostabilisation potential of these plant species provide useful information about their selective exploitation for effective phytoremediation of the tailings dam at Chirano Gold Mine. Keywords: phytoremediation, heavy metal, hyperaccumulation, phytostabilisation, indigenous plants, bioavailable

Neurotransmitter modulation of extracellular H+ fluxes from isolated retinal horizontal cells of the skate

Self-referencing H+-selective microelectrodes were used to measure extracellular H+ fluxes from horizontal cells isolated from the skate retina. A standing H+ flux was detected from quiescent cells, indicating a higher concentration of free hydrogen ions near the extracellular surface of the cell as compared to the surrounding solution. The standing H+ flux was reduced by removal of extracellular sodium or application of 5-(N-ethyl-N-isopropyl) amiloride (EIPA), suggesting activity of a Na+–H+ exchanger. Glutamate decreased H+ flux, lowering the concentration of free hydrogen ions around the cell. AMPA/kainate receptor agonists mimicked the response, and the AMPA/kainate receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) eliminated the effects of glutamate and kainate. Metabotropic glutamate agonists were without effect. Glutamate-induced alterations in H+ flux required extracellular calcium, and were abolished when cells were bathed in an alkaline Ringer solution. Increasing intracellular calcium by photolysis of the caged calcium compound NP-EGTA also altered extracellular H+ flux. Immunocytochemical localization of the plasmalemma Ca2+–H+-ATPase (PMCA pump) revealed intense labelling within the outer plexiform layer and on isolated horizontal cells. Our results suggest that glutamate modulation of H+ flux arises from calcium entry into cells with subsequent activation of the plasmalemma Ca2+–H+-ATPase. These neurotransmitter-induced changes in extracellular pH have the potential to play a modulatory role in synaptic processing in the outer retina. However, our findings argue against the hypothesis that hydrogen ions released by horizontal cells normally act as the inhibitory feedback neurotransmitter onto photoreceptor synaptic terminals to create the surround portion of the centre-surround receptive fields of retinal neuron

Fecal Coliform Removal In Algal-Based Domestic Wastewater Treatment Systems

We hypothesize that the net effect of organic matter (from all sources) in domestic wastewater treatment ponds may tend to promote fecal bacteria survival at higher algal cell concentrations. The aim of this study is to understand better, the role of algae in the removal of fecal bacteria from algal based ponds and to specifically investigate the effect of varying algal concentrations on fecal bacteria removal in algal based ponds. Batch laboratory experiments were conducted using light of wavelengths, 380-780 nm. Algae were grown by natural colonization and used for inoculating the setup

Metal Ceramic Segmented Ring Transducer under Deep Submergence Conditions

Segmented ring transducers are widely used for low frequency, broadband, deep submergence applications. These transducers can be made out of piezoceramic wedges or slabs and metallic wedges. Higher diameter, low frequency transducers are generally made out of piezoceramic slabs and metal wedges due to ease of manufacture and low cost. In this paper, metal ceramic segmented ring transducers are modelled using ATILA, a finite element software for the design of underwater transducers. Transducer variants were modelled with different wedge and piezoceramic materials. Transducers modelled were manufactured, assembled and tested. Various stages of manufacture like piezoceramic stacking, transducer assembly, pre-stressing with fibre winding, and encapsulation are explained. Acoustic performances of the transducers manufactured were measured in an open tank and inside a pressurised vessel from 10 bar to 70 bar. Performance parameters like resonance frequency, transmitting voltage response and directivity were measured. Results indicate that the transducer has usable bandwidth of about two octaves and stable response. One of the transducers was also tested in a high pressure test facility at 600 bar to check its pressure withstanding capability

Architecture and Applications of IoT Devices in Socially Relevant Fields

Number of IoT enabled devices are being tried and introduced every year and there is a healthy competition among researched and businesses to capitalize the space created by IoT, as these devices have a great market potential. Depending on the type of task involved and sensitive nature of data that the device handles, various IoT architectures, communication protocols and components are chosen and their performance is evaluated. This paper reviews such IoT enabled devices based on their architecture, communication protocols and functions in few key socially relevant fields like health care, farming, firefighting, women/individual safety/call for help/harm alert, home surveillance and mapping as these fields involve majority of the general public. It can be seen, to one's amazement, that already significant number of devices are being reported on these fields and their performance is promising. This paper also outlines the challenges involved in each of these fields that require solutions to make these devices reliableComment: 1

Persistence of diet effects on the Drosophila suzukii microbiota

The insect commensal microbiota consists of prokaryotes and eukaryotes. The effect of diet and the persistence of the gut microbiota in Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) are not well-understood. We transferred subsets of a single population of D. suzukii to different fruit-based diets (blueberry, raspberry, and strawberry) for three generations and then returned them to a common, banana-based, laboratory diet. We used 16S (bacteria) and ITS (fungi) sequencing of female endosymbiont-free flies to identify the microbiota. We identified 2700 bacterial and 350 fungal OTUs; there was no correlation between the number of bacterial and fungal OTUs in a sample. Bacterial communities were dominated by Proteobacteria (especially Acetobacteraceae); Ascomycota dominated the fungal communities. Species diversity of both bacteria and fungi differed among diets, but there were no differences in species-level diversity when these flies were returned to a control diet. A Principle Coordinates Analysis revealed no differences in the bacterial or fungal community in the first generation on fruit diets, but that the communities diverged over the next two generations; neither fungal and bacterial communities converged after one generation on control food. We conclude that diet changes the D. suzukii microbiota, and that these changes persist for more than one generation

Biodegradation of Crude Oil Polluted Soil by Co-Composting with Agricultural Wastes and Inorganic Fertilizer

Pollution of the environment by petroleum products is inevitable due to oil production,   transportation and distribution activities.   The present study is aimed at examining the extent of bioremediation that can be achieved in crude oil polluted soil after supplementing with organic manure (poultry droppings and goat dung); inorganic fertilizer (NPK 15:15:15) and saw dust respectively. A bioremediation study was carried out on soil experimentally polluted with Bonny Light crude oil by supplementation with organic and inorganic nutrients (poultry manure, goat dung, saw dust and NPK fertilizer). The efficacy of the treatments was monitored for 112days by the measurement of total hydrocarbon utilizing bacteria load and some physico-chemical parameters. The polluted soil (Control) sample had mean bacterial counts of 8.8x104, 9.0x104, 9.2´104, 9.9x104 and 7.6x104 cfu/g respectively. Sample treated with NPK fertilizer had mean bacterial counts of 4.4x104, 4.6x104, 4.7x104, 4.9x104 and 5.2x104 cfu/g on days 0,28,56,84 and 112 respectively; sample treated with poultry manure had mean bacterial counts of 1.6x104, 1.8x104, 2.0x104, 2.4x104 and 2.7x104 cfu/g on days 0, 28,56,84 and 112 respectively; the saw dust treated sample had mean bacterial counts of 2.0x104, 2.3x104, 2.7x104, 2.9x104 and 3.0x104 cfu/g on days 0,28,56,84 and 112 respectively while that treated with goat dung had mean bacterial counts of 9.3x104, 9.5x104, 9.6x104, 9.8x104and 9.9x104 cfu/g on days 0,28,56,84 and 112 respectively.  There were differences in the physico-chemical analyses from the diverse samples. After statistical analysis (P£0.05) there was a significant difference between the different treated samples from the control. The results suggest that nutrient supplementation would be effective in the remediation of crude oil polluted soils. The potentials of various treatment options for the bioremediation of crude oil polluted soils seems to hold the most immediate solution especially for use in areas that would be adversely affected by physical or other removal methods. In this study, the reduction of oil in the treated samples is evident, polluted samples supplemented with fertilizer and poultry manure respectively proved to be the best options during the 112 days study period. This study shows that those organic supplements containing nitrogen and phosphorus have great potentials for the remediation of soils contaminated with petroleum hydrocarbon within a reasonable time. Keywords: Bioremediation, Crude Oil Polluted Soil, Organic Manure (poultry droppings and goat dung); Inorganic fertilizer (NPK 15:15:15), Saw dust

Is hysterectomy a risk factor for urinary incontinence?

Background: Hysterectomy is the most common gynecological surgery performed. There are few studies evaluating hysterectomy as a risk factor for urinary incontinence. If hysterectomy is found to be a risk factor for developing urinary incontinence, women undergoing hysterectomy can be well informed prior to the procedure regarding the same. The objective of the present study was to study the prevalence of urinary incontinence in post-menopausal women and its relationship to hysterectomy. To evaluate the association of metabolic syndrome, to urinary incontinence.Methods: This study was a prospective cohort study done in Christian Medical College and Hospital, Vellore, Tamil Nadu between December 2016- December 2017. Postmenopausal women both with natural and surgical menopause, were enrolled into the study after an informed consent. The UDI-6 questionnaire was used to assess urinary incontinence. The categorical variables were presented using frequencies and percentages. The comparison of categorical variables was done using Fisher's exact test. The odds ratio and confidence interval were calculated for the prevalence. P value < 0.05 was considered to be statistically significant.Results: A total of 600 women were enrolled into the study with 300 women having attained natural menopause and 300 women with a surgical menopause. The prevalence of urinary incontinence among these post-menopausal women was 46.24%. The prevalence of urinary incontinence amongst the women with natural menopause was 47.3% and amongst the women with surgical menopause was 45% (p = 0.566). Women with metabolic syndrome suffered from urinary incontinence more than their counterparts without metabolic syndrome (55.8% vs. 36%, p <0.0001).Conclusions: The prevalence of urinary incontinence in the natural menopause and surgical menopause groups was similar, thus proving that hysterectomy is not a risk factor for developing urinary incontinence. However, metabolic syndrome was found to be associated with urinary incontinence.

Prevalence of metabolic syndrome among postmenopausal women in South India

Background: As the average life expectancy of women extends 20-30 years after menopause, the medical impacts of changes leading to metabolic syndrome on postmenopausal women are significant. The menopausal state has been noted to be an independent risk factor for the occurrence of metabolic syndrome. This study was conducted to look at the prevalence of metabolic syndrome in postmenopausal women.Methods: A prospective cross sectional study was done and postmenopausal women were assessed for metabolic syndrome using the International Diabetes Federation Criteria.Results: The prevalence of metabolic syndrome was found to be 64%. Women with metabolic syndrome had a higher systolic blood pressure and larger waist circumference, however did not differ in terms of diabetes and dyslipidemia. There was no significant difference with regards to frequency and severity of menopausal symptoms between women with and without metabolic syndrome.Conclusions: The increased prevalence of metabolic syndrome in postmenopausal women may be directly due to ovarian insufficiency and indirectly due to metabolic consequences of central fat redistribution with estrogen deficiency

Cooperativity of Kv7.4 channels confers ultrafast electromechanical sensitivity and emergent properties in cochlear outer hair cells.

The mammalian cochlea relies on active electromotility of outer hair cells (OHCs) to resolve sound frequencies. OHCs use ionic channels and somatic electromotility to achieve the process. It is unclear, though, how the kinetics of voltage-gated ionic channels operate to overcome extrinsic viscous drag on OHCs at high frequency. Here, we report ultrafast electromechanical gating of clustered Kv7.4 in OHCs. Increases in kinetics and sensitivity resulting from cooperativity among clustered-Kv7.4 were revealed, using optogenetics strategies. Upon clustering, the half-activation voltage shifted negative, and the speed of activation increased relative to solitary channels. Clustering also rendered Kv7.4 channels mechanically sensitive, confirmed in consolidated Kv7.4 channels at the base of OHCs. Kv7.4 clusters provide OHCs with ultrafast electromechanical channel gating, varying in magnitude and speed along the cochlea axis. Ultrafast Kv7.4 gating provides OHCs with a feedback mechanism that enables the cochlea to overcome viscous drag and resolve sounds at auditory frequencies