Nested clade analysis of geographic structure in the morphologically variable Themeda triandra in South Africa

The use of phylogeography in plant systems has been on the increase in recent years with the use of chloroplast DNA to detect sufficient intraspecific variation to reach significant conclusions about plant species histories, both temporally and spatially. In this study, the geographic structure and possible origin of the morphologically variable Themeda triandra is explored. The trnF - trnC and psbD - trnS gene regions of the cpDNA were used to find 12 haplotypes found in 11 populations of T. triandra that encompass the species large distributional range. A haplotype tree was constructed that showed the relationship of the 11 haplotypes (haplotype_H12 was excluded as it fell outside of the 95% confidence limit), with haplotype H6 inferred to be the ancestral haplotype. A nested clade analysis was performed with the results used to infer the geographic structure of T. triandra within South Africa. Significant results showed that there was restricted gene flow with nested clades involving the three Free State populations, indicating that there are barriers to gene flow with other haplotypes. The ancestral haplotype showed long distance colonisation, with a probable root of this colonisation being the Kruger National Park. This is the proposed point of introduction of T. triandra into South Africa, with results from this study supporting this proposal. A substantial amount of gene flow (25.49%; AMOV A) between populations is observed, with this probably being due to the widespread distribution of haplotypes H6 and H10. It is thought that T. triandra followed two migration routes within South Africa: one along the coast, with the other inland above the escarpment where populations became genetically isolated from populations below the escarpment. Further studies may look for a correlation between morphological variants of T. triandra and the cpDNA haplotypes found within the species

Taxonomy, phylogeny and eco-biogeography of southern African white-eyes (Zosterops spp.) Aves: order Passeriformes, Family: Zosteropidae

Includes abstract.Includes bibliographical references (p. 193-216).The aim of this study was to incorporate all lines of evidence to establish the true taxonomy and phylogeny of southern African Zosterops. Character data sets used include plumage and morphometric measures, vocal characters and molecular (mitochondrial and nuclear) DNA sequences. A broad scale phylogeographic analysis was also performed to establish the evolutionary process driving the diversity observed among these birds

Gender Issues in Education for Science and Technology: Current Situation and Prospects for Change

Girls and women remain substantially under-represented in mathematics, science, and technology in school and in the workplace. Although this problem is recognized, its complexity is widely underestimated and causes are not well understood. We review prevailing explanations, which tend to concentrate either on possible gender differentials in qualities such as self-confidence, or on school practices that allow boys to dominate classroom interaction and monopolize such technology as computers. We also identify disadvantageous features of higher education and the workplace. We then consider what is known about educational innovation, especially in the area of gender equity, and describe some interventions concerned with gender and science and technology education. Finally, we raise unresolved questions and issues about gender equity efforts in science and technology education and suggest directions for research. Les filles et les femmes sont nettement sous-représentés en mathématiques, en science et en technologie à l’école et sur le marché du travail. Bien que ce problème soit reconnu, sa complexité est largement sous-estimée et ses causes ne sont pas bien comprises. Les auteurs passent en revue les explications qui ont présentement cours, lesquelles tendent à mettre en relief soit les différences qui existeraient entre les sexes pour ce qui est, par exemple, de la confiance en soi, soit les pratiques scolaires qui permettent aux garçons de dominer l’interaction en classe et de monopoliser la technologie, comme les ordina- teurs. Les auteurs identifient également les caractéristiques désavantageuses de l’éducation supérieure et des milieux de travail. Ils se penchent ensuite sur les connaissances actuelles au sujet des innovations en éducation, particulièrement dans le domaine de l’égalité entre les sexes, et décrivent quelques interventions tenant compte du sexe dans l’enseignement des sciences et de la technologie. Ils terminent en soulevant quelques questions non ré- glées au sujet des efforts à faire en matière d’égalité des sexes dans les cours de science et de technologie et proposent des orientations pour la recherche.

Visual Scanning and Its Relationship to Facial Emotion Recognition in Individuals with Traumatic Brain Injuries

Objective: Mounting research evidences a relationship between decreased social integration and reduced facial emotion perception (FEP) after traumatic brain injury (TBI). A relationship between visual scanning and the accurate and fast identification of facial emotions was hypothesized. Study 1 aimed to examine the visual scanning of emotional faces under non-speeded and speeded conditions in a sample of typically developing undergraduate students. The goal of Study 2 was to examine the visual scanning of emotional faces in a convenience sample of patients with TBI in comparison to that of a subset of control participants from Study 1. Scan patterns and their relationship to reaction time and accuracy were examined. Participants and Methods: Study 1 included a sample of 33 (9 males) undergraduate students. Study 2 included 17 typically developing controls (9 males) and 10 patients with TBI (7 males). Both studies employed a novel voice-key eye-tracking paradigm that included angry, disgusted, fearful, happy, sad, and surprised faces. Results: Study 1 illustrates that typically developing adults attend to the eyes of emotional faces more than the nose or the mouth. Mean response times among the typically developing undergraduates were 1-3 seconds faster than the reaction times previously reported in button-press studies. Emotion had a significant effect on visual scanning, reaction time and accuracy in Study 1 and Study 2. In Study 2, patients with TBI attended proportionately less to the eyes and proportionally more to less salient features of emotional faces relative to controls, p < .05. The TBI group was significantly slower to label emotional faces than the control group and significantly less accurate, overall, p < .05. Attending to the lower part of the face was negatively related to accuracy in both groups. Conclusions: Overall, the findings demonstrate that typically developing adults scanning of emotional faces is emotion-specific. This dissertation provides initial evidence that the TBI convenience sample scanned the emotional faces differently than the typically developing group. It suggests that visual scanning is related to FEP accuracy and the speed at which emotional faces are labeled. These findings may provide new avenues for FEP assessment and treatment research

Positive design of smart interactive fabric artifacts for people with dementia

Confronting the expected rise of dementia as a major health care problem raises many questions about the best ways to adapt the health system to deal with it. To the extent that intelligent assistive technologies can help, there seems to be value in comforting fabric artifacts enhanced by electronic games and activities designed to support, engage and entertain people with dementia. Local cottage industries which now support the creation of textile crafts should be empowered to scale up to meet the growing demand for such products. New design concepts are required to accomplish this in the face of rising costs and limited resources. This paper proposes a four-step design process that meets this need, and provides practical suggestions about how it could be applied in this context. A number of examples are included

Comets and Meteors

Defines and describes named comets and meteor events and their scientific study

Proposing a plausible molecular structure for Ice XI: A coupled study using Rietveld refinement and Density Functional Theory

A plausible molecular structure for fully ordered Ice XI is proposed. A range of structures were generated by varying the lattice parameters along the trajectory of the observed Ice Ih/Ice XI phase transition and recording the energy-minimised Density Functional Theory structure (using the Perdew–Wang 1991 functional) for each set of lattice parameters. These proposed structures were then fitted to the neutron data using GSAS-II to extract the goodness-of-fit. It is shown that the Rietveld refinement was insensitive to the OH bond length and the HOH bond angle. The refinement with the lowest value of Rw=6.038% gave OH bond lengths of 0.997(7)Å, 0.999(2)Å, 0.997(5)Å, HOH bond angles of 107.5 and 106.0, and OH...O hydrogen bond lengths of 1.77(4),1.75(2) and 1.75(1)Å. It is therefore apparent that the two crystallographically distinct water molecules have very similar molecular hydrogen bond parameters, which are close to that predicted by previous CASTEP PW91 DFT modelling

ID4 levels dictate the stem cell state in mouse spermatogonia

Spermatogenesis is a classic model of cycling cell lineages that depend on a balance between stem cell self-renewal for continuity and the formation of progenitors as the initial step in the production of differentiated cells. The mechanisms that guide the continuum of spermatogonial stem cell (SSC) to progenitor spermatogonial transition and precise identifiers of subtypes in the process are undefined. Here we used an Id4-eGfp reporter mouse to discover that EGFP intensity is predictive of the subsets, with the ID4-EGFPBright population being mostly, if not purely, SSCs, whereas the ID4-EGFPDim population is in transition to the progenitor state. These subsets are also distinguishable by transcriptome signatures. Moreover, using a conditional overexpression mouse model, we found that transition from the stem cell to the immediate progenitor state requires downregulation of Id4 coincident with a major change in the transcriptome. Collectively, our results demonstrate that the level of ID4 is predictive of stem cell or progenitor capacity in spermatogonia and dictates the interface of transition between the different functional states

Reverse osmosis brine concentration using falling film freeze crystallisation technology: a pilot-scale study

The reverse osmosis (RO) desalination process has increasingly been utilized with aim of producing drinking water from different marginal sources of water such as seawater, and brackish ground and surface water, due to water scarcity. Unfortunately, desalination applications are limited by the brine disposal challenges including the adverse impact of brine on the surrounding environment. Therefore, this paper is focused on the technical evaluation of falling film freeze crystallization (FFFC) technology for treating and concentrating RO brine. An industrial pilot plant using the FFFC process was tested and assessed for concentrating RO brine in this study. The experimental results showed that the crystallization experiments using a feed stage (without the sweating process) and at the operating end-point heat transfer medium (HTM) temperature of –6°C, achieved a salt rejection ratio and water recovery ratio of 56.6% and 49.8% respectively. Whereas at the endpoint HTM temperature of –24°C, the salt rejection ratio and water recovery ratios were 24.5% and 84.6% respectively. The multi-stage process experiments using feed and rectification stages (without the sweating process) achieved a salt rejection and product water recovery ratio of 46.89% and 64.24% respectively. By using a multi-stage process including feed, rectification, and stripping stages (with the sweating process), the salt rejection and product water recovery ratio reached 70.68% and 50.15% respectively. In general, the results showed that the FFFC technology, using a single freezing stage and without the sweating process, would be an ideal treatment system for concentrating RO brine and to produce saline water to near seawater quality that can be used directly as feed water for a RO plant. The research proved that the investigated FFFC process can be considered as a great solution available for brine concentration and as an alternative for reducing the environmental impact of the large volume of waste streams from coastal and inland desalination plants

Moving towards sustainable resources: Recovery and fractionation of nutrients from dairy manure digestate using membranes

The fractionation of nitrogen (as ammonia/ammonium) and phosphorus (as phosphate ions) present in the dairy manure digestate was investigated using a nanofiltration membrane NF270. The filtration and separation efficiencies were correlated to pH across the range 3 &#60; pH &#60; 11. Filtration at pH 11 enabled higher permeate flux of 125–150 LMH at 20 bar, however rejection of ammonia was high at 30–36% and phosphate was 96.4–97.2%. At pH 3 and pH 7, electrostatic charge effects led to higher permeation of ammonium and thus more efficient separation of nitrogen. The rejection of phosphorus was relatively constant at any given pH and determined as 83% at pH 3, 97% at pH 7 and 95% at pH 11. The fractionation of nitrogen and phosphorus from complex aqueous solutions was demonstrated to be highly dependent on the charge of the membrane and ionic speciation. Solutions rich in nitrogen (as ammonia/ammonium) were obtained with almost no phosphorus present (&#60;1 ppm) whilst the purification of the PO4–P was achieved by series of diafiltration (DF) operations which further separated the nitrogen. The separation of nutrients benefited from an advantageous membrane process with potential added value for a wide range of industries. The analysis of the process economics for a membrane based plant illustrates that the recovery of nutrients, particularly NH3–N, may be commercially feasible when compared to manufactured anhydrous NH3