6 research outputs found
Pretoriana, no. 058, Dec. 1968
No full textOnthulling van gedenkplaat Kya Rosa -- Toespraak van Dr. N.A. Coetzee (Voorsitter van Genootskap Oud-Pretoria) by geleentheid van die onthulling van die gedenkplaat by Kya Rosa op 21 Oktober 1978 -- Voorgeskiedenis van terrein waar Kya Rosa staan ... / N.A. Coetzee -- Onthulling van gedenkplaat : toespraak van Mnr. W.W. Haak, 1908 student -- Die straatname van die Pretoriase voorstad Danville / G.J. van Eck -- Die straatname van Danville se uitbreiding no. 1 / G.J. van Eck -- Vernoeming van park in Villieria / G.J. van Eck -- Nog 'n brief uit die boerelaer te Ladysmith / J.F. de Man -- The occupation of Pretoria by the British forces (II), taken from war letters from the veld A.D. 1900 / by C.R. Prance -- The Pretoria Club / A.K.W. Atkinson -- Laerskooltuinkompetisie, 1968 / H. Bruins-Lic
Assessing maintained bed levels in ports
No full textThe accessibility of a port, which is mainly determined by the available water depth, is of economic importance for a port to distinguish itself from other ports. For the vertical design of navigation channels, the goal is to make routes equally accessible and not have bottlenecks; to have an optimal maintenance program and not incur unnecessary costs. Ultimately, the vertical design of channels entails a trade-off between the Maintained Bed Level (MBL), vessel draughts and the percentage of accessibility. The objective of this research is to assess available and required water depths in ports, and to identify opportunities for the vertical design of channels. To reach this objective, a literature study has been carried out. Vertical design approaches, vessel characteristics, local conditions and admission policies are considered. Also, since this topic is strongly related to practice, a relatively large number of interviews were conducted. In this study, a new, more detailed vertical design approach has been framed. The vertical design of channels revolves around available and required water depths. Since parameters to determine these depths vary in time and space, a systemic-view is required to design for the same accessibility percentage along a route. In this research, a general method to quantify accessibility percentages as a function of the MBL in a port-network has been framed. By looping over the MBL, corresponding accessibility percentages can be calculated. As a result, it becomes possible to maintain bed levels for neither too little (bottlenecks) nor too much (unnecessary dredging costs) available water depth. Also, assessing the actual draught of vessels for vertical channel design purposes appears relatively new. A Port of Rotterdam case study is performed to analyse the traffic data and to validate the results of the computer model. Four terminals, with different business-dynamics, handling the largest-draughted vessels, were selected. The results of this study are presented and supported by relevant actors in the port: shipping line, terminal, port authority and pilot. From the traffic study, it was concluded that there can be a significant discrepancy between actual and design vessel draughts. For example, only <0.1% of the largest container vessels (16-17m vessel design draught) handled in the Prinses Amaliahaven (almost) reach the draught for which channels has been designed (17m). Moreover, the MBL model allows a port authority to be more rational about where to maintain for which bed level. By removing structural over-depths, dredging costs can be saved. By removing bottlenecks, entire routes can become more accessible with relatively little dredging work. It would be recommended to review the actual use and accessibility of channels in ports on a regular basis (with the MBL model). The MBL model has a general set up; it can be applied to ports all over the world. Overall, it would be expected that something as fundamental as the MBL would be fully thought out in ports. It is compelling that by combining different data-sets (water levels, actual vessel draughts, and currents in case of a tidal window), room for improvement can be found.Civil Engineering | Hydraulic Engineerin
Pulmonary tuberculosis and COVID-19 coinfection : Hickam’s Dictum revisited
No full textCOVID-19 and pulmonary tuberculosis (PTB) coinfection is associated with increased mortality and presents a unique diagnostic challenge to the clinician. We describe three cases of newly
diagnosed PTB in COVID-19 patients treated at our centre and their clinical and radiological
features. The challenges associated with diagnosis and management are also explored. Patient 1
was a case of smear positive, endobronchial tuberculosis incidentally diagnosed due to CT
changes, and eventually made good recovery. Patient 2 was a case of COVID-19 who succumbed
but was diagnosed posthumously due to a positive sputum culture for tuberculosis. Patient 3
showed radiographic features of PTB and was treated empirically for TB. In conclusion, COVID-19
and PTB coinfection should be suspected in the presence of constitutional symptoms, prior
immunocompromised states, prolonged respiratory symptoms or fever, or unresolved radiological
abnormalities, more so in regions where TB is endemic.
List of abbreviations
TB tuberculosis
PTB pulmonary tuberculosis
CT computed tomography
WHO World Health Organization
NPOP nasopharyngeal and oropharyngeal
CTPA computed tomography pulmonary angiogram
HRCT high resolution computed tomography
GGO ground glass opacities
ATT anti-tuberculous therapy
IGRA interferon-gamma release assay
* Corresponding author. Faculty of Medicine and Health Sciences, Universiti Malaysia Sabah, Kota Kinabalu, Sabah, Malaysia.
E-mail addresses: [email protected] (L.E. Nyanti), [email protected] (Z.H. Wong), [email protected] (B. Sachdev Manjit Singh),
[email protected] (A.K.W. Chang), [email protected] (A.T. Jobli), [email protected] (H.H. Chua).
Contents lists available at ScienceDirect
Respiratory Medicine Case Reports
journal homepage: www.elsevier.com/locate/rmcr
https://doi.org/10.1016/j.rmcr.2022.101653
Received 5 February 2022; Received in revised form 12 March 2022; Accepted 13 April 202
Metabolic engineering of β-oxidation in Penicillium chrysogenum for improved semi-synthetic cephalosporin biosynthesis
No full textIndustrial production of semi-synthetic cephalosporins by Penicillium chrysogenum requires supplementation of the growth media with the side-chain precursor adipic acid. In glucose-limited chemostat cultures of P. chrysogenum, up to 88% of the consumed adipic acid was not recovered in cephalosporin-related products, but used as an additional carbon and energy source for growth. This low efficiency of side-chain precursor incorporation provides an economic incentive for studying and engineering the metabolism of adipic acid in P. chrysogenum. Chemostat-based transcriptome analysis in the presence and absence of adipic acid confirmed that adipic acid metabolism in this fungus occurs via β-oxidation. A set of 52 adipate-responsive genes included six putative genes for acyl-CoA oxidases and dehydrogenases, enzymes responsible for the first step of β-oxidation. Subcellular localization of the differentially expressed acyl-CoA oxidases and dehydrogenases revealed that the oxidases were exclusively targeted to peroxisomes, while the dehydrogenases were found either in peroxisomes or in mitochondria. Deletion of the genes encoding the peroxisomal acyl-CoA oxidase Pc20g01800 and the mitochondrial acyl-CoA dehydrogenase Pc20g07920 resulted in a 1.6- and 3.7-fold increase in the production of the semi-synthetic cephalosporin intermediate adipoyl-6-APA, respectively. The deletion strains also showed reduced adipate consumption compared to the reference strain, indicating that engineering of the first step of β-oxidation successfully redirected a larger fraction of adipic acid towards cephalosporin biosynthesis.
How Does the Pre-weaning Environment Affect Gut Structure and Function, and Lifetime Performance of the Pig?
No full textThe reduction in feed intake and growth rate that occurs following weaning is of major economic consequence to the pig industry. Currently, a range of antimicrobial products can be used to minimise the impact of weaning on piglet health and subsequent performance. However, the use of these products in pig diets is subject to increasing restriction worldwide because of perceived risks to public health and to the environment. Thus, alternative methods are required to mitigate the growth check that almost invariably occurs after weaning in most production systems.
Piglets produced outdoors are claimed to experience less of a growth check at weaning and to be able to thrive in relatively unsophisticated weaner accommodation. However, these claims have not been substantiated under Western Australian conditions, nor a scientific basis for these claims established. Consequently, a series of experiments was designed to test the general hypothesis for this thesis – ‘the gut structure and function, and lifetime performance of the weaned pig are affected by its pre- and post-weaning rearing environments’.
Experiment 1 was conducted in two parts to quantify differences in the growth performance, health and gut structure of weaner pigs produced indoors or outdoors and reared in conventional or deep-litter pens. The weaner diet in the first part of the experiment contained 100 ppm of olaquindox and 3,000 ppm of zinc oxide (Exp1a). This experiment was repeated without using dietary antimicrobial products (Exp1b). Experiment 2 was conducted in conventional buildings to examine the effect of exposing piglets in lactation to similar substrates to those available to outdoor piglets used in Exp1a and Exp1b in the absence of other differences in the outdoor production milieu.
Pre-weaning environments in Exp1a (indoor production (IP) and outdoor production (OP)) appeared to have little effect on gut structure and overall growth rate but significantly affected carcass composition, whereas post-weaning environments (conventional (C) or deep-litter (DL)) affected both overall growth rate and carcass composition. Although feed disappearance was similar, OP pigs grew faster than IP pigs in the first 47 d after weaning in Exp1a but not in Exp1b. Lifetime growth rate (GR), P2 backfat, feed disappearance and feed conversion ratio (FCR) were not significantly affected by the production environment in Exp1a whereas OP pigs grew slower with higher P2 backfat and FCR in Exp1b. Interestingly, OP pigs had heavier carcass weights and higher dressing percentages than IP pigs in both parts of the experiment. The effects of post-weaning environment were more consistent as DL pigs grew faster, were fatter, and had higher carcass weights and dressing percentages than C pigs.
Villus height and crypt depth of IP and OP pigs were not different at 21 (weaning) or 28 d, but villus height decreased and crypt depth increased in the week after weaning. Pigs reared in C pens had greater faecal concentrations of volatile fatty acids than pigs in DL, indicating that the latter ingested sufficient straw to alter fermentation characteristics.
In Experiment 2, there were no differences in gut structure or pre-weaning and lifetime GR of pigs offered no creep feed (NC), a commercial creep feed (CF) or an ‘outdoor’ mix (OM) comprising of 1 part straw, 5 parts sow feed and 25 parts of soil taken from paddocks in which OP pigs used in Exp1a and Exp1b were farrowed. However, NC pigs grew slower in the week after weaning than the other two treatments. Backfat and feed disappearance were similar for all treatments but pigs on the OM treatment had higher carcass weights and dressing percentages than pigs on the NC and CF treatments. Villus height and crypt depth were not different between treatments and, although the piglets were weaned at 28 d, villus height decreased and crypt depth increased in the week after weaning to an extent similar to that experienced by piglets weaned at 21 d in Experiment 1.
Although all piglets received intramuscular injections of 200 mg iron (Fe) dextran when 1 to 2 days old, piglets offered the OM during lactation had higher serum iron and blood haemoglobin (Hb) levels than those offered NC or CF. Furthermore, half the piglets offered NC or CF had Hb levels indicative of chronic Fe deficiency anaemia. The average parity of sows used in this experiment was 6.3 litters, suggesting that piglets may have been born with low Fe stores, possibly because of low Fe stores in their dams due to sub-optimal mineral nutrition over successive parities.
In summary, the findings from these experiments partly supported the general hypothesis for this thesis. Under the conditions of these experiments, access to outdoor substrates in lactation had little effect on gut structure and lifetime growth rate but increased both carcass weight and dressing percentage, whereas rearing in DL pens increased feed intake, FCR, growth rate, P2 backfat, carcass weight and dressing percentage
Low-technology innovation in a sectoral system:a critical realist perspective
No full textThis research aims to generate an in-depth understanding of the existence or nonexistence of low-technology innovation from a sectoral system of innovation (SSI) perspective. Embedded in the critical realist paradigm, this study espouses the notion of a stratified ontology. Moreover, it considers innovation to be systemic and nonsequential influenced by multiple objects and their relations. Deriving from a systematic literature review, this research addresses knowledge gaps including lack of an exclusive and all-encompassing understanding of LT innovation from the critical realist and SSI perspectives. It also addresses the lack of research on the influence of individual within firm, various sectoral elements and sectoral structure on LT innovation through use of a conceptual framework derived from systems thinking, SSI and micro-meso-macro (individual-firm-contextual) framework. Empirically rooted in the marble industry of north-west Pakistan, this research applies retroduction to explain causal mechanisms by understanding events, objects/entities, necessary and contingent relations and causal powers. Following case study approach a multiple (two) case design (embedded type 4) having two cases/sectors, Peshawar Marble Sectoral System (PeMaS) and Buner Marble Sectoral System (BuMaS) has been chosen. A case study protocol has been applied to increase reliability along with a three-phased data collection, the use of mixed methods and a two-step analysis procedure. Research outcomes reveal limited occurrences of incremental LT innovation amongst firms (events). The lack of innovation is a result of the systemic interplay of many sectoral elements identified and presented as the causal mechanisms of stasis. Moreover, the causal mechanisms that can result in LT innovation have been provided, a significant contribution that critical realism makes to the work. Seventy factors (causal powers) that explain the lack of LT innovation categorized across elements/objects and micro-meso-macro origins are discovered. These help identify the extant but latent causal powers that underlie the occurrence of LT innovation. The research makes a number of key contributions. It draws influence from critical realism to understand LT innovation and integrates its tenets with empirical work through use of mixed methods, as opposed to the predominant use of positivism and phenomenology found in previous research. It offers a unique and previously non-existent perspective of the SSI that is all-encompassing and exhaustive. Particularly, it addresses the lack of research on the sectoral elements including individual, learning processes and demand as well as the sectoral structure. Moreover, it complements the SSI approach with a first-time use of a micro-meso-macro (individual-firm-contextual) framework to offer a powerful explanation of the complex interplay within a low-tech SSI. Finally, this research addresses the lack of empirical work on LT innovation from a developing country context
