Global Warming: Predicting OPEC Carbon Dioxide Emissions from Petroleum Consumption Using Neural Network and Hybrid Cuckoo Search Algorithm

Background

Global warming is attracting attention from policy makers due to its impacts such as floods, extreme weather, increases in temperature by 0.7°C, heat waves, storms, etc. These disasters result in loss of human life and billions of dollars in property. Global warming is believed to be caused by the emissions of greenhouse gases due to human activities including the emissions of carbon dioxide (CO₂) from petroleum consumption. Limitations of the previous methods of predicting CO₂ emissions and lack of work on the prediction of the Organization of the Petroleum Exporting Countries (OPEC) CO₂ emissions from petroleum consumption have motivated this research.

Methods/Findings

The OPEC CO₂ emissions data were collected from the Energy Information Administration. Artificial Neural Network (ANN) adaptability and performance motivated its choice for this study. To improve effectiveness of the ANN, the cuckoo search algorithm was hybridised with accelerated particle swarm optimisation for training the ANN to build a model for the prediction of OPEC CO₂ emissions. The proposed model predicts OPEC CO₂ emissions for 3, 6, 9, 12 and 16 years with an improved accuracy and speed over the state-of-the-art methods.

Conclusion

An accurate prediction of OPEC CO₂ emissions can serve as a reference point for propagating the reorganisation of economic development in OPEC member countries with the view of reducing CO₂ emissions to Kyoto benchmarks—hence, reducing global warming. The policy implications are discussed in the paper.     

A controlled trial of the knowledge impact of tuberculosis information leaflets among staff supporting substance misusers: pilot study

Background

Information leaflets are widely used to increase awareness and knowledge of disease. Limited research has, to date, been undertaken to evaluate the efficacy of these information resources. This pilot study sought to determine whether information leaflets developed specifically for staff working with substance mis-users improved knowledge of tuberculosis (TB).

Method

Staffs working with individuals affected by substance mis-use were recruited between January and May 2008. All participants were subjectively allocated by their line manager either to receive the TB-specific leaflet or a control leaflet providing information on mental health. Level of knowledge of TB was assessed using questionnaires before and after the intervention and data analysed using McNemar''s exact test for matched pairs.

Results

The control group showed no evidence of a change in knowledge of TB, whereas the TB questionnaire group demonstrated a significant increase in knowledge including TB being curable (81% correct before to 100% correct after), length of treatment required (42% before to 73% after), need to support direct observation (18% to 62%) and persistent fever being a symptom (56% to 87%). Among key workers, who have a central role in implementing a care plan, 88% reported never receiving any TB awareness-raising intervention prior to this study, despite 11% of all respondents having TB diagnosed among their clients.

Conclusion

Further randomized controlled trials are required to confirm the observed increase in short-term gain in knowledge and to investigate whether knowledge gain leads to change in health status.     

A toolbox for tuberculosis diagnosis: an Indian multicentric study (2006-2008): microbiological results

Background

The aim of this multicentric prospective study in India was to assess the value of several microbiological tools that contribute to the diagnosis of tuberculosis (TB) according to HIV status.

Methods

Standard microbiological tools on individual specimens were analyzed.

Results

Among the 807 patients with active TB, 131 were HIV-infected, 316 HIV-uninfected and 360 had HIV-unknown status. Among the 980 non-active TB subjects, 559 were at low risk and 421 were at high risk of M. tuberculosis (Mtb) exposure. Sensitivity of smear microscopy (SM) was significantly lower in HIV-infected (42.2%) than HIV-uninfected (75.9%) (p = 0.0001) and HIV-unknown pulmonary TB patients (61.4%) (p = 0.004). Specificity was 94.5% in non-TB patients and 100% in health care workers (HCW) and healthy family contacts. Automated liquid culture has significantly higher diagnostic performances than solid culture, measured by sensitivity (74.7% vs. 55.9%) (p = 0.0001) and shorter median time to detection (TTD) (12.0 vs. 34.0 days) (p = 0.0001). Specificity was 100% in HCW and cured-TB patients, but was lower in non-TB patients (89%) due to isolation of Mycobacteria other than tuberculosis (MOTT). TTD by both methods was related to AFB score. Contamination rate was low (1.4%). AccuProbe hybridization technique detected Mtb in almost all culture-positive specimens, but MOTT were found in 4.7% with a significantly higher frequency in HIV-infected (15%) than HIV-uninfected TB patients (0.5%) (p = 0.0007). Pre-test classification significantly increased the diagnostic value of all microbiological tests in pulmonary TB patients (p<0.0001) but to a lesser degree in extrapulmonary TB patients.

Conclusions

Conventional microbiological tools led to results similar to those already described in India special features for HIV-infected TB patients included lower detection by SM and culture. New microbiological assays, such as the automated liquid culture system, showed increased accuracy and speed of detection.     

Clinical Features of Severe Malaria Associated with Death: A 13-Year Observational Study in The Gambia

Background

Severe malaria (SM) is a major cause of death in sub-Saharan Africa. Identification of both specific and sensitive clinical features to predict death is needed to improve clinical management.

Methods

A 13-year observational study was conducted from 1997 through 2009 of 2,901 children with SM enrolled at the Royal Victoria Teaching Hospital in The Gambia to identify sensitive and specific predictors of poor outcome in Gambian children with severe malaria between the ages 4 months to 14 years. We have measured the sensitivity and specificity of clinical features that predict death or development of neurological sequelae.

Findings

Impaired consciousness (odds ratio {OR} 4.4 [95% confidence interval {CI}, 2.7–7.3]), respiratory distress (OR 2.4 [95%CI, 1.7–3.2]), hypoglycemia (OR 1.7 [95%CI, 1.2–2.3]), jaundice (OR 1.9 [95%CI, 1.2–2.9]) and renal failure (OR 11.1 [95%CI, 3.3–36.5]) were independently associated with death in children with SM. The clinical features that showed the highest sensitivity and specificity to predict death were respiratory distress (area under the curve 0.63 [95%CI, 0.60–0.65]) and impaired consciousness (AUC 0.61[95%CI, 0.59–0.63]), which were comparable to the ability of hyperlactatemia (blood lactate>5 mM) to predict death (AUC 0.64 [95%CI, 0.55–0.72]). A Blantyre coma score (BCS) of 2 or less had a sensitivity of 74% and specificity of 67% to predict death (AUC 0.70 [95% C.I. 0.68–0.72]), and sensitivity and specificity of 74% and 69%, respectively to predict development of neurological sequelae (AUC 0.72 [95% CI, 0.67–0.76]).The specificity of this BCS threshold to identify children at risk of dying improved in children less than 3 years of age (AUC 0.74, [95% C.I 0.71–0.76]).

Conclusion

The BCS is a quantitative predictor of death. A BCS of 2 or less is the most sensitive and specific clinical feature to predict death or development of neurological sequelae in children with SM.     

Aryl sulfatase from Naja nigricolis venom: characterization and possible contribution in the pathology of snake poisoning

The venom of Naja nigricolis was found to contain a high level of the enzyme aryl sulfatase. The enzyme was isolated from the venom of N. nigriclois and purified to electrophoretic homogeneity by gel chromatography on Sephadex G-100, DEAE-cellulose, and phenyl-sepharose columns. The enzyme was optimally active at pH 5 and 40 degrees C. Arrhenius plot for the determination of the activation energy (E(a)) gave the value 25 kJ/mol with a half-life (t(1/2)) of 5 min at 50 degrees C. It was highly activated by Fe(2+) and Ca(2+) and inhibited by Co(2+) and Mn(2+). The enzyme catalyzed the hydrolysis of the fluorescent compound methylumbelliferyl-sulfate (MU-SO(4)). Double reciprocal plots of initial velocity data, using MU-SO(4) as substrate, gave a K(M) value of 110 microM and V(max) of 225 micromol min(-1) x mg(-1). N. nigricolis Aryl sulphatase also hydrolyzed chondroitin-4-sulphate. It was inhibited competitively by N-acetyl glucosamine sulfate (GlcNAc-SO(4)), glucose-6-sulfate (Glc-6-SO(4)), and glucose 1-sulfate (Glc-1-SO(4)). Extrapolated inhibition binding constants (K(i)) gave the values of 3, 25, and 315 microM for GlcNAc-SO(4), Glc-6-SO(4), and Glc-1-SO(4) respectively.     

Inferring the evolutionary history of rice yellow mottle virus from genomic, phylogenetic, and phylogeographic studies

Fourteen isolates of Rice yellow mottle virus (RYMV) were selected as representative of the genetic variability of the virus in Africa from a total set of 320 isolates serologically typed or partially sequenced. The 14 isolates were fully sequenced and analyzed together with two previously reported sequences. RYMV had a genomic organization similar to that of Cocksfoot mottle sobemovirus. The average nucleotide diversity among the 16 isolates of RYMV was 7%, and the maximum diversity between any two isolates was 10%. A strong conservative selection was apparent on both synonymous and nonsynonymous substitutions, through the amino acid replacement pattern, on the genome size, and through the limited number of indel events. Furthermore, there was a lack of positive selection on single amino acid sites and no evidence of recombination events. RYMV diversity had a pronounced and characteristic geographic structure. The branching order of the clades correlated with the geographic origin of the isolates along an east-to-west transect across Africa, and there was a marked decrease in nucleotide diversity moving westward across the continent. The insertion-deletion polymorphism was related to virus phylogeny. There was a partial phylogenetic incongruence between the coat protein gene and the rest of the genome. Overall, our results support the hypothesis that RYMV originated in East Africa and then dispersed and differentiated gradually from the east to the west of the continent.     

Trpc2 pseudogenization dynamics in bats reveal ancestral vomeronasal signaling,then pervasive loss

Comparative methods are often used to infer loss or gain of complex phenotypes, but few studies take advantage of genes tightly linked with complex traits to test for shifts in the strength of selection. In mammals, vomerolfaction detects chemical cues mediating many social and reproductive behaviors and is highly conserved, but all bats exhibit degraded vomeronasal structures with the exception of two families (Phyllostomidae and Miniopteridae). These families either regained vomerolfaction after ancestral loss, or there were many independent losses after diversification from an ancestor with functional vomerolfaction. In this study, we use the Transient receptor potential cation channel 2 (Trpc2) as a molecular marker for testing the evolutionary mechanisms of loss and gain of the mammalian vomeronasal system. We sequenced Trpc2 exon 2 in over 100 bat species across 17 of 20 chiropteran families. Most families showed independent pseudogenizing mutations in Trpc2, but the reading frame was highly conserved in phyllostomids and miniopterids. Phylogeny‐based simulations suggest loss of function occurred after bat families diverged, and purifying selection in two families has persisted since bats shared a common ancestor. As most bats still display pheromone‐mediated behavior, they might detect pheromones through the main olfactory system without using the Trpc2 signaling mechanism.     

High intracellular Zn<Superscript>2+</Superscript> ions modulate the VHR,ZAP-70 and ERK activities of LNCaP prostate cancer cells

Malignant prostate tissues have markedly reduced zinc (Zn(2+)) contents in comparison to non-malignant tissues. In this study, we restored a high intracellular Zn(2+) level to LNCaP prostate cancer cells by culturing the cells in a growth medium supplemented with a supraphysiological concentration of Zn(2+) (10 mug/ml) over 5 weeks. The intracellular Zn(2+) level increased in the Zn(2+)-treated cells, and there was a marked increase in the presence of zincosomes, a Zn(2+)-specific intracellular organelle. The proliferation rate of the Zn(2+)-treated cells was markedly reduced. There was also a significant increase (36.6% +/- 6.4%) in the total tyrosine phosphorylated proteins. Vaccinia H1-related (VHR) phosphatase, zeta chain-associated protein-70 (ZAP-70) kinase and phosphorylated extracellular signal-regulated protein kinase 1 and 2 (p-ERK 1 and 2) were also present in higher abundance. Treatment with TPEN, which chelates Zn(2+), reduced the abundance of VHR phosphatase and ZAP-70 kinase, but increased the abundance of p-ERK 1. However, the TPEN treatment restored the Zn(2+)-treated LNCaP cell proliferation to a rate comparable to that of the non Zn(2+)-treated cells. These results highlight the importance of a high intracellular Zn(2+) content and the VHR/ZAP-70-associated pathways in the modulation of LNCaP prostate cancer cell growth.