An Empirical Investigation into the Dimensions of Run-Time Coupling in Java Programs

Software quality is an important external software attribute that is di±cult to measure objectively. Several studies have identified a clear empirical relationship between static coupling metrics and software quality. However due to the nature of object-oriented programs, static metrics fail to quantify all the underlying dimensions of coupling, as program behaviour is a function of its operational environment as well as the complexity of the source code. In this paper a set of run-time object-oriented coupling metrics are described. A method of collecting such metrics which utilises the Java Platform Debug Architecture is described and a collection of Java programs from the SPECjvm98 benchmark suite are evaluated. A number of statistical techniques including descriptive statistics, a correlation study and principal component analysis are used to assess the fundamental properties of the measures and investigate whether they are redundant with respect to the Chidamber and Kemerer static CBO metric. Results to date indicate that run-time coupling metrics can provide an interesting and informative qualitative analysis of a program and complement existing static coupling metrics

Impact of a drier Early–Mid-Holocene climate upon Amazonian forests

This paper uses a palaeoecological approach to examine the impact of drier climatic conditions of the Early–Mid-Holocene (ca 8000–4000 years ago) upon Amazonia's forests and their fire regimes. Palaeovegetation (pollen data) and palaeofire (charcoal) records are synthesized from 20 sites within the present tropical forest biome, and the underlying causes of any emergent patterns or changes are explored by reference to independent palaeoclimate data and present-day patterns of precipitation, forest cover and fire activity across Amazonia. During the Early–Mid-Holocene, Andean cloud forest taxa were replaced by lowland tree taxa as the cloud base rose while lowland ecotonal areas, which are presently covered by evergreen rainforest, were instead dominated by savannahs and/or semi-deciduous dry forests. Elsewhere in the Amazon Basin there is considerable spatial and temporal variation in patterns of vegetation disturbance and fire, which probably reflects the complex heterogeneous patterns in precipitation and seasonality across the basin, and the interactions between climate change, drought- and fire susceptibility of the forests, and Palaeo-Indian land use. Our analysis shows that the forest biome in most parts of Amazonia appears to have been remarkably resilient to climatic conditions significantly drier than those of today, despite widespread evidence of forest burning. Only in ecotonal areas is there evidence of biome replacement in the Holocene. From this palaeoecological perspective, we argue against the Amazon forest ‘dieback’ scenario simulated for the future

Addressing the theory practice gap in nurse education: evaluating teaching through audit against NMC standards and final management placement

IntroductionThis paper outlines an innovative approach to auditing and evaluating the content of a management and leadership module for undergraduate nursing students after their final management clinical placement. Normally evaluations of teaching in a module take place at the end of a teaching module and therefore do not properly reflect the value of the teaching in relation to practical clinical experience. AimThis audit and evaluation sought to explore both the practical value of the teaching and learning, and also the degree to which it the teaching reflected against the NMC Standards of Education and Learning (2010 domain 3).MethodsHaving piloted the evaluative tool with an earlier cohort of nursing students, this evaluation explored both a quantitative assessment employing a Personal Response System (n =172), together with a qualitative dimension (n=116), thus delivering paper-based comments and reflections from students on the value and practicality of the module teaching theory to their final clinical management experience. The quantitative audit data were analysed for frequencies and cross tabulation and the qualitative audit data were thematically analysed.ResultsResults suggest a significant proportion of the students, appreciated the quality of the standard of teaching, but more importantly, ‘valued or highly valued’ the teaching and learning in relation to how it helped to significantly inform their management placement experience. A smaller proportion of the students underlined limitations and areas in which further improvement can be made in teaching and learning to the module.ConclusionSignificantly positive evaluation by the students of the practical value of teaching and learning, to the theoretical management module. This has proved a useful auditing approach in assessing the theoretical teaching to student’s Level 3 clinical experience, and facilitated significant recommendations as far as developing the teaching and learning to better reflect the practice needs of nursing students<br/

Fire, climate and vegetation linkages in the Bolivian Chiquitano seasonally dry tropical forest

South American seasonally dry tropical forests (SDTFs) are critically endangered, with only a small proportion of their original distribution remaining. This paper presents a 12 000 year reconstruction of climate change, fire and vegetation dynamics in the Bolivian Chiquitano SDTF, based upon pollen and charcoal analysis, to examine the resilience of this ecosystem to drought and fire. Our analysis demonstrates a complex relationship between climate, fire and floristic composition over multi-millennial time scales, and reveals that moisture variability is the dominant control upon community turnover in this ecosystem. Maximum drought during the Early Holocene, consistent with regional drought reconstructions, correlates with a period of significant fire activity between 8000 and 7000 cal yr BP which resulted in a decrease in SDTF diversity. As fire activity declined but severe regional droughts persisted through the Middle Holocene, SDTFs, including Anadenanthera and Astronium, became firmly established in the Bolivian lowlands. The trend of decreasing fire activity during the last two millennia promotes the idea among forest ecologists that SDTFs are threatened by fire. Our analysis shows that the Chiquitano seasonally dry biome has been more resilient to Holocene changes in climate and fire regime than previously assumed, but raises questions over whether this resilience will continue in the future under increased temperatures and drought coupled with a higher frequency anthropogenic fire regime

Factors influencing epiphytic moss and lichen distribution within Killarney National Park

The niches of epiphytes are widely studied and have been shown to be complex involving interspecific competition, succession and predation. This study is unique in that it applies the niche concept to moss and lichen distributions within Killarney National Park, Kerry, Ireland. We studied 75 trees between three pristine ancient woodlands and measured a range of physical and biological factors to ascertain influences on epiphyte cover. The species of tree was found as the principal determinant in community structure as it bioengineers conditions such as light, temperature and humidity that the epiphytes are reliant upon. Furthermore, the bark character and trunk circumference were important. Zonation of the epiphytes was apparent with both aspect and height on the trunk. Typically, moss dominated over lichen within a niche that was relatively sheltered. Lichen tolerated drier and lighter niches often being further up the trunk on sun facing aspects. Ultimately, there was succession up the tree mediated through competition. This study highlights the complexity and interrelatedness between biotic and abiotic factors in a relatively unstudied geographical and biological area. Understanding agents behind a population's distribution enables manipulation for conservation or sustainable exploitation

Human Fire Legacies on Ecological Landscapes

The primacy of past human activity in triggering change in earth’s ecosystems remains a contested idea. Treating human-environmental dynamics as a dichotomous phenomenon – turning “on” or “off” at some tipping point in the past – misses the broader, longer-term, and varied role humans play in creating lasting ecological legacies. To investigate these more subtle human-environmental dynamics, we propose an interdisciplinary framework, for evaluating past and predicting future landscape change focused on human-fire legacies. Linking theory and methods from behavioral and landscape ecology, we present a coupled framework capable of explaining how and why humans make subsistence decisions and interact with environmental variation through time. We review evidence using this framework that demonstrates how human behavior can influence vegetation cover and continuity, change local disturbance regimes, and create socio-ecological systems that can dampen or even override, the environmental effects of local and regional climate. Our examples emphasize how a long-term interdisciplinary perspective provides new insights for assessing the role of humans in generating persistent landscape legacies that go unrecognized using a simple natural-versus-human driver model of environmental change

The Amazon River Basin as an Analog for the Pre-Ice Age Bell River Basin of North America

The pre-ice age Bell River basin of North America was comparable in size to the modern day Amazon basin of South America. In Miocene time, it drained most of Canada and one third of the North American continent before being defeated by tectonics, volcanism, and glaciation. Beginning about 2.5 million years ago, continental glaciers re-routed the paths of the tributaries in Canada, leaving behind only traces of this once massive river basin in headwater valleys in the Rocky Mountains and in a giant river delta in the Labrador Sea. The contemporary Amazon River basin provides an analog for estimating fluvial parameters of the ancient Bell River system. Both systems had headwaters in high mountains and canyons, then drained across flat, continental-scale basins, and emptied into the Atlantic Ocean through broad continental rift zones. Both have large deltas and long submarine turbidity channels. Comparing the Amazon\u27s delta, tributaries, stream gradients, and sediment loads to the remnants of the Bell River system could support a model for pre-ice age North American drainage. This could then augment studies of tectonic displacements in the western interior, for example, uplift of the Great Plains and Rocky Mountains, effects of Yellowstone volcanism, and faulting in the Great Basin

The impact of stellar and AGN feedback on halo-scale baryonic and dark matter accretion in the EAGLE simulations

Large scale structure and cosmolog