Modelling and simulation framework for reactive transport of organic contaminants in bed-sediments using a pure java object - oriented paradigm

Numerical modelling and simulation of organic contaminant reactive transport in the environment is being increasingly relied upon for a wide range of tasks associated with risk-based decision-making, such as prediction of contaminant profiles, optimisation of remediation methods, and monitoring of changes resulting from an implemented remediation scheme. The lack of integration of multiple mechanistic models to a single modelling framework, however, has prevented the field of reactive transport modelling in bed-sediments from developing a cohesive understanding of contaminant fate and behaviour in the aquatic sediment environment. This paper will investigate the problems involved in the model integration process, discuss modelling and software development approaches, and present preliminary results from use of CORETRANS, a predictive modelling framework that simulates 1-dimensional organic contaminant reaction and transport in bed-sediments

Structure, conduct and performance of Plantain Marketing in Edo State, Nigeria

The study examined the conduct, structure and performance of plantain marketing in Edo State. The objectives of the study were to examine the structure and conduct of plantain marketing system, assess its performance and estimate the cost and returns in plantain marketing. Data for the study were collected using a well-structured questionnaire administered to 240 marketers of plantain selected using a two–stage sampling process involving random and purposive sampling techniques. Data collected were analyzed using descriptive statistics, gross margin analysis, marketing margins, marketing efficiency and the Gini-coefficient. The results indicate that the market was characterized with many buyers and sellers reflecting a pure competitive structure, prices were determined mainly by factors such as purchase price, ability of the buyers to haggle, supply and demand forces and cost of transportation. Market associations existed among the marketers but only 32.42% belonged to such associations. Most of the respondents agreed that they used both open display and persuasive efforts to attract customers. The value of the Gini coefficient (0.677) indicates some level of inequality suggesting the presence of market concentration among the respondents. The results indicated a net profit of N15.70 per kg of raw plantain. The marketing margin of #32.1 and efficiency of 95.79% indicate reasonably good performance. © JASE

Redistribution and Subsidies for Higher Education

The financing of higher education through public spending imposes a transfer of resources from taxpayers to university students and their parents. We provide an explanation for this phenomenon. Those who attend higher education will earn more income in the future and will pay more taxes. People whose children do not attend higher education, however should agree to help pay the cost of such education, providing that the taxes are sufficiently high to ensure that there will be an adequate redistribution in favor of their own children at some time in the future.Higher Education, Taxation, Redistribution

Bitcoin Crypto - bounties for quantum capable adversaries

With the advances in quantum computing taking place over the last few years, researchers have started considering the implications on cryptocurrencies. As most digital signature schemes would be impacted, it is somewhat reassuring that transition schemes to quantum resistant signatures are already being considered for Bitcoin. In this work, we stress the danger of public key reuse, as it prevents users from recovering their funds in the presence of a quantum enabled adversary despite any transition scheme the developers decide to implement. We emphasize this threat by quantifying the damage a functional quantum computer could inflict on Bitcoin (and Bitcoin Cash) by breaking exposed public keys

Growth study on chrysene degraders isolated from polycyclic aromatic hydrocarbon polluted soils in Nigeria

Acinetobacter anitratus, Alcaligenes faecalis, Acinetobacter mallei and Micrococcus varians were isolated from polycyclic aromatic hydrocarbon polluted soils by enrichment culture using chrysene assole carbon and energy source. Physiochemical evaluation revealed that these isolates grew well at a temperature range of 20 - 40°C, pH 6.0-8.0 but less tolerable to various salt concentrations except Micrococcus varians which grew at 1.0 to 7.5% NaCl. These organisms utilized chrysene, anthracene, naphthalene, crude oil, kerosene, diesel and engine oil as sole carbon source. None could utilize benzene, hexane, xylene, phenol and toluene as carbon sources. Growth study of the isolates on 0.1%(w/v) chrysene resulted in highest cell density of 8.8x107, 7.9x107, 6.3x106, 6.3x106 cfu/ml for A. anitratus, Alc. faecalis, A. mallei and M. varians, respectively. There was statistical significant difference (P< 0.05) in the growth of these organisms on chrysene as sole carbon and energy source when compared with non-chrysene control. This study indicates the potential of these hitherto unreported tropical bacterial strains as chrysene degraders and their use in biodegradation processes involvingpetrochemical product

Demographic Features, Beliefs And Socio–Psychological Impact Of Acne Vulgaris Among Its Sufferers In Two Towns In Nigeria

There is paucity of reports in the demographic knowledge, belief and socio-psychological impact of acne vulgaris sufferers towards the disorder in a black population. This is the first study from Nigeria designed to address this issue. A total of 174 facial acne sufferers completed a self-administered questionnaire, which contained several items mentioning different areas in their belief, knowledge, perception, severity, socio-psychological impact and medication attention. The findings were discussed and compared to those of the Caucasians. The occurrence of the disorder was higher in females (65.0%) compared to the males (35.0%). About 54.0% of the female subjects indicated increase in severity of the disorder during their pre-menstrual period. Also 64.9% of acne sufferers indicated increase in severity during the rainy season, while 93.1% of the population implicated stress to perpetuate the severity of the disorder. Most (75.7%) of the acne sufferers believed that it is caused by oily diet, 40.8% thought that it is hereditary, while barely 5.2% had at sometime sought doctor's attention. Non- prescription products used by acne sufferers were cleansers and cream/lotions. Psychological abnormalities experienced by the sufferers included social inhibition, depression and anxiety. Pain and discomfort are the psychosomatic symptoms. No major differences were found in the beliefs, misconception and socio-psychological impact of acne sufferers in a black population (Nigeria) compared to the Caucasians. There is need to improve the understanding of the disorder in Nigeria through health education programmes

Ab initio theory of helix-coil phase transition

In this paper we suggest a theoretical method based on the statistical mechanics for treating the alpha-helix-random coil transition in alanine polypeptides. We consider this process as a first-order phase transition and develop a theory which is free of model parameters and is based solely on fundamental physical principles. It describes essential thermodynamical properties of the system such as heat capacity, the phase transition temperature and others from the analysis of the polypeptide potential energy surface calculated as a function of two dihedral angles, responsible for the polypeptide twisting. The suggested theory is general and with some modification can be applied for the description of phase transitions in other complex molecular systems (e.g. proteins, DNA, nanotubes, atomic clusters, fullerenes).Comment: 24 pages, 3 figure

A method for sensitivity analysis to assess the effects of measurement error in multiple exposure variables using external validation data

Measurement error in self-reported dietary intakes is known to bias the association between dietary intake and a health outcome of interest such as risk of a disease. The association can be distorted further by mismeasured confounders, leading to invalid results and conclusions. It is, however, difficult to adjust for the bias in the association when there is no internal validation data