Hydrochemical characteristics and identification of groundwater pollution sources in tropical savanna.

Groundwater pollution of the watershed is mainly influenced by the multifaceted interactions of natural and anthropogenic processes. In this study, classic chemical and multivariate statistical methods were utilized to assess the groundwater quality and ascertain the potential contamination sources affecting the groundwater quality of Galma sub-watershed in a tropical savanna. For this purpose, the data set of 18 groundwater quality variables covering 57 different sampling boreholes (BH) was used. The groundwater samples essentially contained the cations in the following order of dominance: Ca2+ > Na+ > Mg2+ > K+. However, the anions had HCO3- > Cl- > SO4-2 > NO3- respectively. The hydrochemical facies classified the groundwater types of the sub-watershed into mixed Ca-Mg-Cl type of water, which means no cations and anions exceeds 50%. The second dominant water type was Ca-Cl. The Mg-HCO3 water type was found in BH 9, and Na-Cl water type in BH 29 of the studied area. The weathering of the basement rocks was responsible for the concentrations of these ions in the groundwater chemistry of the sub-watershed. Hierarchical cluster analysis (HCA) grouped the groundwater samples (boreholes) into five clusters that are statistically significant regarding the similarities of groundwater quality characteristics. The principal component analysis (PCA) extracted two major principal components explained around 65% of the variance and suggested the natural and anthropogenic processes especially the agricultural pollutants including synthetic fertilizers, and leaching of agricultural waste as the main factors affecting the groundwater quality. The integrated method proved to be efficient and robust for groundwater quality evaluation, as it guaranteed the precise assessment of groundwater chemistry in the sub-watershed of the tropical savanna. The findings of this investigation could be useful to the policy makers for developing effective groundwater management plans for the groundwater resources and protection of the sub-watershed.

High pyrethroid/DDT resistance in major malaria vector Anopheles coluzzii from Niger-Delta of Nigeria is probably driven by metabolic resistance mechanisms.

Entomological surveillance of local malaria vector populations is an important component of vector control and resistance management. In this study, the resistance profile and its possible mechanisms was characterised in a field population of the major malaria vector Anopheles coluzzii from Port Harcourt, the capital of Rivers state, in the Niger-Delta Region of Nigeria. Larvae collected in Port-Harcourt, were reared to adulthood and used for WHO bioassays. The population exhibited high resistance to permethrin, deltamethrin and DDT with mortalities of 6.7% ± 2.4, 37.5% ± 3.2 and 6.3% ± 4.1, respectively, but were fully susceptible to bendiocarb and malathion. Synergist bioassays with piperonylbutoxide (PBO) partially recovered susceptibility, with mortalities increasing to 53% ± 4, indicating probable role of CYP450s in permethrin resistance (χ2 = 29.48, P < 0.0001). Transcriptional profiling revealed five major resistance-associated genes overexpressed in the field samples compared to the fully susceptible laboratory colony, Ngoussou. Highest fold change (FC) was observed with GSTe2 (FC = 3.3 in permethrin exposed and 6.2 in unexposed) and CYP6Z3 (FC = 1.4 in exposed and 4.6 in unexposed). TaqMan genotyping of 32 F0 females detected the 1014F and 1575Y knockdown resistance (kdr) mutations with frequencies of 0.84 and 0.1, respectively, while 1014S mutation was not detected. Sequencing of a fragment of the voltage-gated sodium channel, spanning exon 20 from 13 deltamethrin-resistant and 9 susceptible females revealed only 2 distinct haplotypes with a low haplotype diversity of 0.33. The findings of high pyrethroid resistance but with a significant degree of recovery after PBO synergist assay suggests the need to move to PBO-based nets. This could be complemented with carbamate- or organophosphate-based indoor residual spraying in this area.

Aspect extraction on user textual reviews using multi-channel convolutional neural network.

Aspect extraction is a subtask of sentiment analysis that deals with identifying opinion targets in an opinionated text. Existing approaches to aspect extraction typically rely on using handcrafted features, linear and integrated network architectures. Although these methods can achieve good performances, they are time-consuming and often very complicated. In real-life systems, a simple model with competitive results is generally more effective and preferable over complicated models. In this paper, we present a multichannel convolutional neural network for aspect extraction. The model consists of a deep convolutional neural network with two input channels: a word embedding channel which aims to encode semantic information of the words and a part of speech (POS) tag embedding channel to facilitate the sequential tagging process. To get the vector representation of words, we initialized the word embedding channel and the POS channel using pretrained word2vec and one-hot-vector of POS tags, respectively. Both the word embedding and the POS embedding vectors were fed into the convolutional layer and concatenated to a one-dimensional vector, which is finally pooled and processed using a Softmax function for sequence labeling. We finally conducted a series of experiments using four different datasets. The results indicated better performance compared to the baseline models.

Effects of Water pH on Life History Parameters of a New Bosminid Cladocera: Bosmina (Bosmina) Tripurae (Korinek, Saha and Bhattachaya, 1999) in Laboratory Condition.

The effects of water pH on life history parameters of Bosmina tripurae have been studied to determine the most suitable water pH desired for the maximum growth and development of this newly discovered cladoceran species. The study was carried out under the laboratory condition at 20 ± 2°C. Five pH ranges 5.0 ± 0.2, 6.0 ± 0.2, 7.0 ± 0.2, 8.0 ± 0.2 and 9.0 ± 0.2 with six replicates for each pH consisting of one animal in each Petri dish (80 × 15 mm) were used for the study. 20 mL of respective test medium was maintained with Chlorella sp. (2 × 104 ± 0.03 cells mL-1) in each Petri dish throughout the experiment. Thirty (30) animals were observed daily to investigate different life history parameters like total life span, age at maturity, number of eggs, neonates and egg batches etc. at different condition. From the study it was found that acidic water (pH 5 ± 0.2) is more suitable for the culture of Bosmina tripurae in laboratory condition.

Subcellular localization, substrate specificity and crystallization of duodenase, a potential activator of enteropeptidase.

Duodenase, a serine protease from bovine duodenum mucosa, was located in endoplasmic reticulum, the Golgi secretory granules of epithelial cells and ducts of Brunner's glands by the A-gold immunocytochemical method. Duodenase exhibits trypsin-like and chymotrypsin-like specificities with a preference for substrates having lysine at the P1 and proline at the P2 positions. The kinetic constants for the hydrolysis of 21 potential duodenase substrates are reported. The best substrates were found to be alpha-N-tosylglycylprolyllysine 4-nitroanilide (k[cat]/Km of 35000 M[-1] s[-1]), alpha-N-succinylthreonylprolyllysine 4-nitroanilide (k[cat]/Km of 18000 M[-1] s[-1]) and alpha-N-serylprolyllysine 4-nitroanilide (k[cat]/Km of 2600 m[-1] s[-1]), all of which contain the P1-P3 sequence of the enteropeptidase zymogen/activation site. On the basis of its catalytic properties and sites of localization, duodenase has been postulated to be an activator of the enteropeptidase precursor. A tetradecapeptide (LVTQEVSPKIVGGS) having the P9-P5'sequence of the cleavage site of zymogen activation of bovine proenteropeptidase was synthesized, and kinetic parameters of its hydrolysis by duodenase were determined (Km of 87 microM; k[cat] of 1.4 s[-1]; k[cat]/Km of 16000 M[-1] s[-1]). Crystals of duodenase frozen in a stream of liquid nitrogen diffracted synchrotron X-rays to 0.2-nm resolution.