The effects of stand characteristics on the understory vegetation in Quercus petraea and Q. cerris dominated forests

The shelterwood system used in Hungary has many effects on the composition and structure of the herb layer. The aim of our study was to identify the main variables that affect the occurence of herbs and seedlings in Turkey oak-sessile oak (Quercus cerris and Q. petraea) stands. The study was carried out in the Bükk mountains, Hungary. 122 sampling plots were established in 50-150 year old oak forests, where we studied the species composition and structure of the understorey and overstorey. The occurence of herbs was affected by canopy closure, the heterogenity and patchiness of the stand, the slope and the east-west component of the aspect. The composition of saplings was significantly explained by the ratio of the two major oak species in the stand and the proximity of the adult plants. An important result for forest management was that sessile oaks were able to regenerate almost only where they were dominant in the overstorey

Versatile Coordination of Cyclopentadienyl-Arene Ligands and Its Role in Titanium-Catalyzed Ethylene Trimerization

Cationic titanium(IV) complexes with ansa-(η5-cyclopentadienyl,η6-arene) ligands were synthesized and characterized by X-ray crystallography. The strength of the metal-arene interaction in these systems was studied by variable-temperature NMR spectroscopy. Complexes with a C1 bridge between the cyclopentadienyl and arene moieties feature hemilabile coordination behavior of the ligand and consequently are active ethylene trimerization catalysts. Reaction of the titanium(IV) dimethyl cations with CO results in conversion to the analogous cationic titanium(II) dicarbonyl species. Metal-to-ligand backdonation in these formally low-valent complexes gives rise to a strongly bonded, partially reduced arene moiety. In contrast to the η6-arene coordination mode observed for titanium, the more electron-rich vanadium(V) cations [cyclopentadienyl-arene]V(NiPr2)(NC6H4-4-Me)+ feature η1-arene binding, as determined by a crystallographic study. The three different metal-arene coordination modes that we experimentally observed model intermediates in the cycle for titanium-catalyzed ethylene trimerization. The nature of the metal-arene interaction in these systems was studied by DFT calculations.

Structures Related to the Emplacement of Shallow-Level Intrusions

A systematic view of the vast nomenclature used to describe the structures of shallow-level intrusions is presented here. Structures are organised in four main groups, according to logical breaks in the timing of magma emplacement, independent of the scales of features: (1) Intrusion-related structures, formed as the magma is making space and then develops into its intrusion shape; (2) Magmatic flow-related structures, developed as magma moves with suspended crystals that are free to rotate; (3) Solid-state, flow-related structures that formed in portions of the intrusions affected by continuing flow of nearby magma, therefore considered to have a syn-magmatic, non-tectonic origin; (4) Thermal and fragmental structures, related to creation of space and impact on host materials. This scheme appears as a rational organisation, helpful in describing and interpreting the large variety of structures observed in shallow-level intrusions

Monitoring and evaluation of sport-based HIV/AIDS awareness programmes: strengthening outcome indicators

There are number of Non-Governmental Organisations (NGOs) in South Africa that use sport as a tool to respond to Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS), however, little is reported about the outcomes and impact of these programmes. The aim of this study is to contribute to a generic monitoring and evaluation framework by improving the options for the use of outcome indicators of sport-based HIV/AIDS awareness programmes of selected NGOs in South Africa. A qualitative method study was carried out with seven employees of five selected NGOs that integrate sport to deliver HIV/AIDS programmes in South Africa. The study further involved six specialists/experts involved in the field of HIV/ AIDS and an official from Sport Recreation South Africa (SRSA). Multiple data collection instruments including desktop review, narrative systematic review, document analysis, one-on-one interviews and focus group interview were used to collect information on outcomes and indicators for sport-based HIV/AIDS awareness programmes. The information was classified according to the determinants of HIV/AIDS. The overall findings revealed that the sport-based HIV/AIDS awareness programmes of five selected NGOs examined in this study focus on similar HIV prevention messages within the key priorities highlighted in the current National Strategic Plan for HIV/AIDS, STIs and TB of South Africa. However, monitoring and evaluating outcomes of sport-based HIV/AIDS programmes of the selected NGOs remains a challenge. A need exists for the improvement of the outcome statements and indicators for their sport-based HIV/AIDS awareness programmes. This study proposed a total of 51 generic outcome indicators focusing on measuring change in the knowledge of HIV/AIDS and change in attitude and intention towards HIV risk behaviours. In addition, this study further proposed a total of eight generic outcome indicators to measure predictors of HIV risk behaviour. The selected NGOs can adapt the proposed generic outcomes and indicators based on the settings of their programmes. A collaborative approach by all stakeholders is required, from international organisations, funders, governments, NGOs and communities to strengthening monitoring and evaluation of sport-based HIV/AIDS awareness programmes including other development programmes. This will assist the NGOs that use sport for development to be able to reflect accurately the information about their HIV/AIDS activities and also be able to contribute to on-going monitoring activities at a national and global level as well as to the Sustainable Development Goals.IS

Deformational and metamorphic history of Moinian and Lewisian rocks between Strathconon and Glen Affric

Seven distinct sets of fold structures have been recognised within 450 square kilometres of Moinian and Lewisian rocks. The earliest structures are only locally preserved, and are deformed by major folds which originally had approximately NE.-SW. axial traces and very variable axial directions. The formation of these folds was associated with high-grade Barrovian metamorphism and with the development of major slides. A pair of large N.-S. folds subsequently deformed this major fold pattern, apparently under conditions of fairly low metamorphic grade. High-grade metamorphism persisted or was re-established in part of the region during the formation of later structures oblique to the dominant regional trend. Subsequently a widespread set of folds whose style and orientation vary with varying metamorphic grade was superposed. In the area of higher grade these have approximately NE.-SW. axial traces, but their attitude in rocks of lower grade is more variable. Formation of another locally-developed set intervened between this widespread folding and the development of the last structures, which are mainly small NE.-SW. folds formed under low-grade conditions. Possible correlations with events in other parts of the Northern Highlands are discussed