Emergent behaviour in a chlorophenol-mineralising three-tiered microbial `food web'

Anaerobic digestion enables the water industry to treat wastewater as a resource for generating energy and recovering valuable by-products. The complexity of the anaerobic digestion process has motivated the development of complex models. However, this complexity makes it intractable to pin-point stability and emergent behaviour. Here, the widely used Anaerobic Digestion Model No. 1 (ADM1) has been reduced to its very backbone, a syntrophic two-tiered microbial food chain and a slightly more complex three-tiered microbial food web, with their stability analysed as function of the inflowing substrate concentration and dilution rate. Parameterised for phenol and chlorophenol degradation, steady-states were always stable and non-oscillatory. Low input concentrations of chlorophenol were sufficient to maintain chlorophenol- and phenol-degrading populations but resulted in poor conversion and a hydrogen flux that was too low to sustain hydrogenotrophic methanogens. The addition of hydrogen and phenol boosted the populations of all three organisms, resulting in the counterintuitive phenomena that (i) the phenol degraders were stimulated by adding hydrogen, even though hydrogen inhibits phenol degradation, and (ii) the dechlorinators indirectly benefitted from measures that stimulated their hydrogenotrophic competitors; both phenomena hint at emergent behaviour.Comment: 19 pages, 8 figure

A WEB-BASED ENVIRONMENTAL TOOLKIT TO SUPPORT SMES IN THE IMPLEMENTATION OF AN ENVIRONMENTAL MANAGEMENT SYSTEM

With small and medium sized-enterprises (SMEs) taking up the majority of the global businesses, it is important they act in an environmentally responsible manner. Environmental management systems (EMS) help companies evaluate and improve their environmental impact but they often require human, financial, and temporary resources that not all SMEs can afford. This research encompasses interviews with representatives of two small enterprises in Germany to provide insights into their understanding, and knowledge of an EMS and how they perceive their responsibility towards the environment. Furthermore, it presents a toolkit created especially for small and medium-sized enterprises. It serves as a simplified version of an EMS based on the ISO 14001 standard and is evaluated by target users and appropriate representatives. Some of the findings are: while open to the idea of improving their environmental impact, SMEs do not always feel it is their responsibility to do so; they seem to lack the means to fully implement an EMS. The developed toolkit is considered useful and usable and recommendations are drawn for its future enhancement

Changing priorities in maternal and perinatal health in Gert Sibande District, South Africa

Gert Sibande District is a predominantly rural district in Mpumalanga Province, South Africa (SA), with a population of just over 1.1 million. It has a high prevalence of HIV infection and pregnancy-related hypertensive disease. In 2010 the district was one of the worst-performing health districts in SA, with a maternal mortality ratio of 328.0 per 100 000 births. Various programmes were introduced between 2010 and 2017 to address major causes of maternal and perinatal morbidity and mortality in the district. The focus has been on HIV-related morbidity, the direct obstetric causes of maternal and perinatal morbidity and mortality, and health systems strengthening. During the period 2010 - 2017, there was a steady decline in institutional maternal mortality with a drop of 71% in maternal deaths over a period of 6 years, from 328.0 per 100 000 births to 95.0. However, the ratio levelled off in 2016 and 2017, mainly as a result of a changing disease profile. The stillbirth rate showed a decline of 24.4% over a period of 8 years. With perseverance, rapid response and evidence-based strategies it was possible to more than halve the institutional maternal mortality ratio within 6 years. However, with the changing disease profile, conditions such as hypertensive disease in pregnancy should be prioritised and new strategies developed to further reduce maternal and perinatal mortality and morbidity

Sustainable Availability Provision in Distributed Cloud Services

The article is an extension of this paper 1 . It describes methods for dealing with reliability and fault tolerance issues in cloud-based datacenters. These methods mainly focus on the elimination of a single point of failure within any component of the cloud infrastructure, availability of infrastructure and accessibility of cloud services. Methods for providing the availability of hardware, software and network components are also presented. The analysis of the actual accessibility of cloud services and the mapping of a cloud-based datacenter infrastructure with different levels of reliability to the Tier Classification System2 is described. Non-compliance of the actual accessibility with the level of High Availability for cloud web services is unraveled

Scaling up kangaroo mother care in South Africa: 'on-site' versus 'off-site' educational facilitation

Background Scaling up the implementation of new health care interventions can be challenging and demand intensive training or retraining of health workers. This paper reports on the results of testing the effectiveness of two different kinds of face-to-face facilitation used in conjunction with a well-designed educational package in the scaling up of kangaroo mother care. Methods : Thirty-six hospitals in the Provinces of Gauteng and Mpumalanga in South Africa were targeted to implement kangaroo mother care and participated in the trial. The hospitals were paired with respect to their geographical location and annual number of births. One hospital in each pair was randomly allocated to receive either 'on-site' facilitation (Group A) or 'off-site' facilitation (Group B). Hospitals in Group A received two on-site visits, whereas delegates from hospitals in Group B attended one off-site, 'hands-on' workshop at a training hospital. All hospitals were evaluated during a site visit six to eight months after attending an introductory workshop and were scored by means of an existing progress-monitoring tool with a scoring scale of 0-30. Successful implementation was regarded as demonstrating evidence of practice (score >10) during the site visit. Results : There was no significant difference between the scores of Groups A and B (p = 0.633). Fifteen hospitals in Group A and 16 in Group B demonstrated evidence of practice. The median score for Group A was 16.52 (range 00.00-23.79) and that for Group B 14.76 (range 07.50-23.29). Conclusion : A previous trial illustrated that the implementation of a new health care intervention could be scaled up by using a carefully designed educational package, combined with face-to-face facilitation by respected resource persons. This study demonstrated that the site of facilitation, either on site or at a centre of excellence, did not influence the ability of a hospital to implement KMC. The choice of outreach strategy should be guided by local circumstances, cost and the availability of skilled facilitators

Generic Modal Cut Elimination Applied to Conditional Logics

We develop a general criterion for cut elimination in sequent calculi for propositional modal logics, which rests on absorption of cut, contraction, weakening and inversion by the purely modal part of the rule system. Our criterion applies also to a wide variety of logics outside the realm of normal modal logic. We give extensive example instantiations of our framework to various conditional logics. For these, we obtain fully internalised calculi which are substantially simpler than those known in the literature, along with leaner proofs of cut elimination and complexity. In one case, conditional logic with modus ponens and conditional excluded middle, cut elimination and complexity were explicitly stated as open in the literature

The development of the human aspects of information security questionnaire (HAIS-Q)

The Human Aspects of Information Security Questionnaire (HAIS-Q) is being developed using a hybrid inductive, exploratory approach, for the purpose of evaluating information security threats caused by employees within organisations. This study reports on the conceptual development and pre-testing of the HAIS-Q. Results from 500 Australian employees were then used to examine the reliability of the HAIS-Q, as well as the relationships between knowledge of policy and procedures, attitude towards policy and procedures and behaviour when using a work computer. Results indicate significant, positive relationships between all variables. However, both qualitative and quantitative results indicate the direct influence of knowledge of policy and procedure accounted for far less of the variance in self-reported behaviour than attitude towards policy and procedure. Implications for training and education campaigns and plans for future research to further develop this questionnaire are outlined

Increased placental resistance and late decelerations associated with severe proteinuric hypertension predicts poor fetal outcome

CITATION: Pattinson, R. C. et al. 1989. Increased placental resistance and late decelerations associated with severe proteinuric hypertension predicts poor fetal outcome. South African Medical Journal, 75:211-214.The original publication is available at http://www.samj.org.zaThe flow velocity wave forms generated by Doppler ultrasound examination of the umbilical artery were correlated with feto-placental blood flow and numerically expressed as a ratio between the systolic (A) and the end-diastolic point (B). The technique is non-invasive and simple to perform. A cohort analytical study was done to see whether useful information could be obtained from the A/B ratio that could help in the management of patients with severe proteinuric hypertension. Fifty patients with severe proteinuric hypertension at less than 34 weeks' gestation were studied and serial Doppler ultrasound examinations of the umbilical artery were performed. No ultrasound results were made available to the clinician. An A/B ratio of 6 or greater was regarded as increased. Twenty-eight of the patients had an increased A/B ratio; in this group these 14 infants were small for gestational age, 14 developed late decelerations and there were 12 perinatal deaths. The remaining 22 patients had an A/B ratio of less than 6 and only 3 produced infants which were small for gestational age; 2 fetuses developed late decelerations and there was 1 perinatal death. A significant difference was found between the two groups in respect of these results. The group with an abnormal A/B ratio also experienced more neonatal morbidity. The A/B ratio of the umbilical artery wave form may assist in planning delivery of patients with severe proteinuric hypertension more accurately.Publisher’s versio