Trace element and polysaccharide sorption in a lacustrine biofilm

Twenty-four elements (Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Ga, K, Li, Mg, Mn, Ni, Pb, Rb, Se, Sr, Ti, U, V, Zn, and Zr) were determined in freshwater biofilms from Lake Mead by inductively coupled plasma mass spectrometry and flame atomic absorption spectrophotometry. The uptake of polysaccharides (as glucose) was determined by ultraviolet/visible spectrophotometry. Taxonomic identification of the biofilm was determined using a stereo and compound microscopes. Major components included the diatoms Cyclotella, Fragilaria, Cymbella, and Amphora. Results for both major cations and trace elements presented for filtered lake water and for particulates filtered from the water suggest that the accumulation of the inorganic fraction of the biofilm is \u27masked\u27; possibly by significant accumulation of the organic fraction. This is evidenced by lower bioaccumulation factors determined during later stages of biofilm development. This masking seems to be less of a factor during the winter and spring seasons. The influence of suspended particulates on the bioaccumulation factor of the metals could be much greater than the influence of dissolved species. This is evidenced by comparing the bioaccumulation factors calculated from data obtained by measuring the elements in particulate matter and filtered lake water from five 1-L field samples. Calcification of the biofilm appears to be microbially influenced and was prevalent during the warmer sampling periods. Accumulations of iron and manganese in the biofilm can be attributed to the presence of photo-reducing bacteria and to low concentrations of these elements in the surrounding water. Such elemental enrichments hint at possible photo-reducing reactions taking place within the biofilm involving iron (Fe (III) {dollar}\to{dollar} Fe (II)) and manganese (manganese oxides {dollar}\to{dollar} Mn (II))

Gynaecological referrals to Baragwanath Hospital

Three hundred and fifty-nine consecutive referral letters to Baragwanath Hospital's gynaecological outpatients' departn:lent were analysed. Letters from private doctors contained significantly less clinical infonnation than those from clinics. Only11% of referring private doctors mentioned what treatment they had given patients before sending them to hospital. Soweto clinic nurses tended to include more information in their letters than clinic doctors. There were no significant differencesin the number of appropriate referrals and incorrect diagnoses from private doctors, clinic doctors and clinic nurses respectively. The poor communication, especially between general practitioners and the hospital, is probably the result of overwork and lack of time. Hospital doctors should reply to well-written referral letters, andliaison between clinics and the hospital ought to be improved and expanded

Online Advertising Revenue and the Operations of Newspapers in Nigeria: A Qualitative Analysis

Online advertising revenue is arguably a great innovation with ambivalent impact on the operations and management of newspaper industry all over the world. The yields from this innovation is seen as a huge source of survival to newspaper outfits and at the same time pose a lot of challenges for newspapers to establish and maintain online versions. The foregoing has nonetheless led some newspaper outfits to have a fair share of advertising revenue as well as expand their readership base while others have derailed and gone moribund. This study therefore seeks to evaluate the interface between online advertising revenue and operations of newspapers in Nigeria. The study adopts the qualitative analytical approach in highlighting relevant concepts to the topic of inquiry and concludes that Nigeria newspaper industry have joined their counterparts all over the world to have online presence and then enjoy a fair share of online advertising revenue. It recommends among others that newspaper establishments in Nigeria should strive to balance their quest for advertising revenue and professional ethics of journalism. Key words: Online advertising revenue, Operations of newspapers, Qualitative analysis, Nigeria.          

Influence of the Oral Microbiome on General Health

The prevalence of edentulism is common worldwide. While improvements in access to healthcare and dental care are reducing the prevalence rate of edentulism, the rapidly growing number of elderly as a percent of the global population will sustain a need for denture therapy for the foreseeable future. While denture use has positive impacts on the quality of life, their use is associated with some problems and risks. Denture stomatitis, a chronic infection-related inflammatory disorder of the oral mucosa, is extremely common and has been reported to occur in up to two-thirds of denture wearers. Importantly, epidemiology studies have shown edentulism and denture wearing, while not proven as causative factors, to be associated with significant increases in risk for serious systemic diseases, such as chronic obstructive pulmonary disease (COPD), cardiovascular diseases, diabetes, and arthritic disorders. A common linkage across these diseases is an association between increased risk for the disease and chronic inflammation. The nature of surface properties and porosity of denture materials contributes to the attachment of microorganisms and the establishment and growth of the adherent biofilm. Hence, proper denture cleansing is critical in maintaining oral hygiene and general health and perhaps to reduce the risk factors for systemic disease

Localizing the Latent Structure Canonical Uncertainty: Entropy Profiles for Hidden Markov Models

This report addresses state inference for hidden Markov models. These models rely on unobserved states, which often have a meaningful interpretation. This makes it necessary to develop diagnostic tools for quantification of state uncertainty. The entropy of the state sequence that explains an observed sequence for a given hidden Markov chain model can be considered as the canonical measure of state sequence uncertainty. This canonical measure of state sequence uncertainty is not reflected by the classic multivariate state profiles computed by the smoothing algorithm, which summarizes the possible state sequences. Here, we introduce a new type of profiles which have the following properties: (i) these profiles of conditional entropies are a decomposition of the canonical measure of state sequence uncertainty along the sequence and makes it possible to localize this uncertainty, (ii) these profiles are univariate and thus remain easily interpretable on tree structures. We show how to extend the smoothing algorithms for hidden Markov chain and tree models to compute these entropy profiles efficiently.Comment: Submitted to Journal of Machine Learning Research; No RR-7896 (2012

The Entropy of a Binary Hidden Markov Process

The entropy of a binary symmetric Hidden Markov Process is calculated as an expansion in the noise parameter epsilon. We map the problem onto a one-dimensional Ising model in a large field of random signs and calculate the expansion coefficients up to second order in epsilon. Using a conjecture we extend the calculation to 11th order and discuss the convergence of the resulting series

The Performance of Decentralized Forest Management: The Study of Rufiji District Council in Tanzania

Over the past two decades, the forest management services in Tanzania were decentralized to local government for the purpose of increasing its efficiency but the current evaluations show that the delivery of the services does not meet the standards and expectations set at the beginning. The goal of this article is to explore the performance of decentralised forest management and the extent to which institutional nexus: formal rules, policies, guidelines, and informal social rules affect the behaviour of local government officials involved in forest management at different levels. Based on the nature of this research, the qualitative approach was adopted with Rufiji district council as a case study. The actual research began with data collection through documentary reviews and in-depth interviews with 80 forest management officials at different levels and harvesters. The research shows that the number of institutional factors such as legal and policy framework, accountability framework and social rules particularly corruption affects the behaviour of forest officials, the community and other stakeholders involved in forest management at Rufiji district council