A limnological investigation of lake Liambezi, Caprivi

A general investigation was carried out on Lake Liambezi to characterize the limnological features of the lake. The lake, 101 km' in area and situated within the tropics, was found to be shallow and bordered by reed swamps, particularly on the south-western shore. It was polymictic and consequently oxygen levels were high at all depths. Transparency was such that photosynthesis occurred to the bottom. Conductivity ranged from 17,3 to 41,2 rnSm and the waters were moderately alkaline. Transfer of organic detritus from the reed swamp into the open water has resulted in the presence of high levels of organic nitrogen and phosphorus whilst ambient levels of inorganic were low. Planktonic chlorophyll a concentrations ranged between 1 and 104 I1g /and Microsystis was the dominant phytoplankter. The dominant zooplankter was Bosmina.The important species of phytoplankton and zooplankton are listed and include two new species of blue-green algae which are described. The lake was found to be generally similar to most shallow tropical African lakes with a wide diversity of food sources for fish. Progressive encroachment by Salvinia appears to hamper access to fishing areas and the fishery potential is threatened

Professionalism, Golf Coaching and a Master of Science Degree: A commentary

As a point of reference I congratulate Simon Jenkins on tackling the issue of professionalism in coaching. As he points out coaching is not a profession, but this does not mean that coaching would not benefit from going through a professionalization process. As things stand I find that the stimulus article unpacks some critically important issues of professionalism, broadly within the context of golf coaching. However, I am not sure enough is made of understanding what professional (golf) coaching actually is nor how the development of a professional golf coach can be facilitated by a Master of Science Degree (M.Sc.). I will focus my commentary on these two issues

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

A zooplankton study of Hartbeespoort Dam

M.Sc. (Zoology)Please refer to full text to view abstrac

Natalobatrachus bonebergi (Anura: Ranidae): aspects of early development and adult size

The early development and adult size of Natalobatrachus bonebergi were investigated. Newly hatched tadpoles were normally about 12,5 mm long. Fore-limb emergence occurred at a total length of 35 to 41 mm after 60 to 125 days of development in the laboratory. Body length was 12 to 13 mm at the end of metamorphosis, and reached two to three times this length at sexual maturity. Hind-limb growth correspon- ,ded closely in natural and laboratory populations and served to indicate pre- and pro-metamorphic phases. Rapid increase in hind-limb length occurred only after tadpoles had reached 30 mm in total length

Effective Tool Support for Architectural Knowledge Sharing

Abstract. Knowledge management plays an important role in the software architecting process. Recently, this role has become more apparent by a paradigm shift that views a software architecture as the set of architectural design decisions it embodies. This shift has sparked the discussion in both research and practice on how to best facilitate sharing of so-called architectural knowledge, and how tools can best be employed. In order to design successful tool support for architectural knowledge sharing it is important to take into account what software architecting really entails. To this end, in this paper we define the main characteristics of architecting, based on observations in a large software development organization, and state-of-the-art literature in software architecture. Based on the defined characteristics, we determine how best practices known from knowledge management could be used to improve architectural knowledge sharing. This results in the definition of a set of desired properties of architectural knowledge sharing tools. To improve the status quo of architectural knowledge sharing tools, we present the design of an architectural knowledge sharing platform.