Living in a changing world: an integrated approach to documenting and understanding medium to long-term vegetation changes in three contrasting land use systems in a mesic savanna, Nothern Zululand, South Africa

There is an increasing amount of evidence suggesting that the balance between trees and grasses in savannas and grasslands has been disrupted in the recent past. Numerous studies from around the world have reported an increasing woody component at the expense of the grass layer. The causes most frequently cited for this shift are linked to changing land use practices. This study was therefore set up to investigate the effects of three contrasting land use systems on long-term vegetation dynamics in a mesic savanna. I aimed to determine if land m;e practices alone could account for the changes in vegetation cover evident at the study sites between 1937 and 2004. An alternative explanation for the changes could be linked to a global driver such as changing climate or increasing atmospheric CO2 concentrations. The rate and extent of vegetation changes were measured and recorded in areas that have remained under communal, commercial and conservation tenure for approximately the past century. Changes in vegetation were determined for a 25 km2 area in each area using repeat panchromatic aerial photography from 193 7, 1960 and 2004. Images were mosaicked and georeferenced then overlaid and manually classified. A comparison between manual classifications and machine-generated classifications using eCognition software was also undertaken. Past land use practices for the three study areas were reconstructed using a combination of archive materials and oral histories. The managers, land users or landowners from areas under communal, commercial and conservation tenure were extensively interviewed to determine their perceptions of the changes, consequences of the changes and reactions to the changes in vegetation. The results showed that significant increases in woody cover occurred during the 67-year period at all three sites. The communal study site showed the least increase in tree cover. However, the overall increase in tree cover at the communal site, from 6.2 to 25.7 % (fourfold increase), is still a highly significant change. The greatest increase in tree cover was evident at the commercial study site where tree cover increased seventeen fold. Total tree cover increased from 2.7 to 50.8 % during the 67-year period. The increase in tree cover at the conservation study site was also highly significant. Tree cover increased by ~360 %, from 14.7 % in 1937 to58.5 % in 2004. These vegetation changes correspond to major losses of grassy habitats in each area. The biodiversity losses associated with these changes are largely unknown but are likely to be substantial. Past land use practices and histories in each area were also shown to be significantly different with major differences in human densities, stocking rates, herbivore feeding types and burning practices. Long-term rainfall records did not show any significant changes in the quantity or seasonality of rainfall. The results suggest that past land use practices did have some impact on the type of and extent of bush encroachment. The study found that although the land users were aware of and concerned about the changes in woody cover in each area, they were not doing much to combat these changes. The perceived importance of the different causes of woody increase was also found to be substantially different amongst the different land users. The findings suggest that land use practices alone cannot explain the widespread occurrence of bush encroachment in the area. This could suggest that a global driver is contributing to the increasing tree component

Gray Area Ethical Leadership in the NCAA: The Ethics of Doing the Wrong Things Right

The NCAA’s operating manuals provide member institutions with hundreds of pages of bylaws that outline how member institutions should operate their athletic programs. Interpretations of these rules can lead to sanctions for student-athletes, coaches, athletic administrators and institutions. Such rule-based systems can potentially lead to the belief that simply following the rules as written equates to right or ethical behavior. In this commentary, we used an ethical leadership framework primarily built on the leadership and management thoughts of Bennis and Nanus (1985) to propose the College Athletics Ethical Leadership Continuum which can be used to assess the behaviors, rules, and decisions made by NCAA membership. Fundamental principles of this conceptual model include holding the student-athlete as the primary stakeholder of college sports activities, and that a critical analysis of the present is necessary to provide leadership for the future. Based on a distinction between doing things right and doing the right thing, the model is applied to four case studies in which NCAA membership policies and actions, or lack thereof, are likely compromising the wellbeing and academic success of student-athletes

Crystallization and preliminary crystallographic analysis of the DNA gyrase B protein from B-stearothermophilus

DNA gyrase B (GyrB) from B. stearothermophilus has been crystallized in the presence of the non-hydrolyzable ATP analogue, 5'-adenylpl-beta-gamma-imidodiphosphate (ADPNP), by the dialysis method. A complete native data set to 3.7 Angstrom has been collected from crystals which belonged to the cubic space group I23 with unit-cell dimension a = 250.6 Angstrom. Self-rotation function analysis indicates the position of a molecular twofold axis. Low-resolution data sets of a thimerosal and a selenomethionine derivative have also been analysed. The heavy-atom positions are consistent with one dimer in the asymmetric unit

Talking it through: using specialist coaching to enhance teachers’ knowledge from speech and language sciences

Teachers’ knowledge for effective pedagogies can be enhanced by drawing on a range of specific expertise held by those working in other disciplines or professions. In this article, we explore this potential through a focus on enhancing research-informed communication rich pedagogies in primary and early years’ settings. The specific example is that of speech and language therapists using video-based coaching with teachers. Our research provides case study evidence and demonstrates that this professional development approach brings speech and language therapy research and expertise into the practice domain of teachers. This is a dynamic, reciprocal and co-constructive relationship between the participants. The focus on this paper is on how it can enable teachers to extend their understanding and develop a more nuanced understanding of specialist evidence of speech, language and communication for, and in, practice

Estimate solar contribution to the global surface warming using the ACRIM TSI satellite composite

We study, by using a wavelet decomposition methodology, the solar signature on global surface temperature data using the ACRIM total solar irradiance satellite composite by Willson and Mordvinov. These data present a +0.047%/decade trend between minima during solar cycles 21-23 (1980-2002). We estimate that the ACRIM upward trend might have minimally contributed $\sim$10-30% of the global surface temperature warming over the period 1980-2002

Different tumours induced by benzo(a)pyrene and its 7,8-dihydrodiol injected into adult mouse salivary gland.

A comparison has been made between the carcinogenic activities of benzo(a)pyrene and the proposed proximate carcinogen, benzo(a)pyrene 7,8-dihydrodiol, in the adult C57BL mouse submandibular salivary gland. In preliminary studies using a range of doses, the dihydrodiol was slightly less active than the parent hydrocarbon in this system. There was a difference in the type of tumour induced by the 2 compounds. Benzo(a)pyrene induced tumours of the salivary glands at the site of injection, whereas the dihydrodiol induced malignant lymphosarcomas, particularly of the thymus, which were often metastatic to other orgnas. Possible reasons for the different sites of action of the 2 compounds are discussed