Effects of temperature variation on TSD in turtle (C. picta) populations

We formulate a two-sex model of temperature-dependent sex determination (TSD) for a freshwater turtle (C. picta) population. The aim is to understand how environmental temperature variations and nest heat conduction properties affect the long term dynamics of the population. This is a key to understanding how global temperature changes may affect their survival. With stochastic inputs of ambient temperature and solar radiation, the model uses the heat equation to determine the temperature in the egg layer in the nest; in turn, this determines the sex ratio in the egg clutch using a variable degree-day model. Finally, a nonlinear Leslie type, stage-based, two-sex model, is used to determine the long term male and female populations. A two-sex model is required because of different development rates for males and females. The model is flexible enough to enable other researchers to examine the effects of temperature variation variations on other species with TSD, e.g., crocodilians, reptilians, as well as other turtle species. It can be adapted to study effects of nest location, soil type, rain events, different incubation periods, and density effects, for example, the dependence of the mating function on the ratio of males to females and each’s contribution to the sex of hatchlings. Modifications can be easily made to fit a specific life history traits. The model is a beginning step in understanding the long term, high fitness shown by many reptile species with TSD, and it may suggest to experimentalists what data may be relevant to these issues; it can also be useful to wildlife managers in developing strategies for intervention if needed. Among the principal findings are that temperature variability and detailed nest heat conduction properties may buffer projected negative effects on a population.     

An optimal level of dust explosion risk management: Framework and application

The current research provides guidance on the prevention and mitigation of dust explosion using a Quantitative Risk Management Framework (QRMF). Using concepts drawn from previous studies, the framework consists of three main steps: (i) a new combined safety management protocol, (ii) the use of DESC (Dust Explosion Simulation Code) and FTA (Fault Tree Analysis) to assess explosion consequences and likelihood, respectively, and (iii) application of the hierarchy of controls (inherent, engineered and procedural safety). QRMF assessment of an industrial case study showed that the original process was at high risk. DESC simulations and Probit equations determined the destructive percentages. FTAs revealed high probabilities of explosion occurrence; in addition, detailed individual and societal risks calculations were made, before and after the framework was applied. Based on the hierarchy of controls technique, the framework showed significant risk reduction to the point where the residual risk was acceptable for the process.     

废旧电路板的解离特性分析

废旧电路板的回收方法依赖于电路板的性质,因此从定性和定量的角度确定废旧电路板上各种物质的组成和含量,对处理技术的选择非常重要。本论文主要针对目前数量最多的废旧电路板（PCB）,利用选矿技术的分离方法进行废旧电路板的解离特性研究。即破碎后的物料首先通过筛分试验确定物料的粒级组成;通过小浮沉试验确定每个粒级的金属和非金属含量。为后续分选作业的可行性提供依据。     

Tasmanian landowner preferences for conservation incentive programs: a latent class approach

An empirical model of landowners' conservation incentive program choice is developed in which information about landowners' socio-economic and property characteristics and their attitudes, is combined with incentive program attributes. In a Choice survey landowners were presented with the choice of two incentive programs modelled as 'bundles of attributes' mimicking a voluntary choice scenario. Landowner behaviour and decision and the type of conditions and regulations they preferred were analyzed. Based on choice survey data, landowner heterogeneity was accounted for using a latent class approach to estimate the preference parameters. Three latent classes of landowners with different attitudes to the role and outcome of establishing conservation reserves on private land were identified: multi-objective owners; environment owners; and production owners. Only a small proportion of landowners, mostly environment owners, would voluntarily join a program. Although compensation funding contributed to voluntary program choice for multi-objective owners and environment owners, welfare losses were around 4000 AUD per hectare, which is less than the average agricultural land value in Tasmania. Landowners for whom compensation funding contributed to voluntary program choice were also most likely to set aside land for conservation without payment. This raises the possibility that the government's compensation expenditure could potentially be either reduced or re-allocated to landowners who will not voluntarily take conservation action. Increasing participation in conservation incentive programs and minimizing the welfare losses associated with meeting conservation targets may be best achieved by offering programs that allow flexibility in terms of legal arrangements and other program attributes.     

Predicting intertidal organism temperatures with modified land surface models

Animals and plants in the marine intertidal zone live at the interface between terrestrial and marine environments. This zone is likely to be a sensitive indicator of the effects of climate change in coastal ecosystems, because of several key characteristics including steep environmental gradients, rapid temperature changes during tide transitions, fierce competition for limited space, and a community of mostly sessile organisms. Here we describe a modular modeling approach using modifications to a meteorological land surface model to determine body temperatures of the ecologically dominant rocky intertidal mussel Mytilus californianus, as a tool that can be used as a proxy for ecological performance. We validate model results against in situ measurements made with biomimetic body temperature sensors. Model predictions lie within the range of variability of biomimetic measurements, based on observations over a 4-year period at sites along 1700 km of the US west coast from southern California (34.5°N) to northern Washington (48.4°N). Our modular approach can be easily applied to many situations in the intertidal zone, including bare rock, mussel, barnacle, and algal beds, salt-marsh grasses, and sand- and mud-flats, by modifying the “vegetation layer” in a standard meteorological land surface model. Biophysical models such as these, which link ecological processes to changing climates through predictions of body temperature, are essential for understanding biogeographic patterns of physiological stress and mortality risk.     

Scientists' opinions on the global status and management of biological diversity

The large investments needed if loss of biological diversity is to be stemmed will likely lead to increased public and political scrutiny of conservation strategies and the science underlying them. It is therefore crucial to understand the degree of consensus or divergence among scientists on core scientific perceptions and strategies most likely to achieve given objectives. I developed an internet survey designed to elucidate the opinions of conservation scientists. Conservation scientists (n =583) were unanimous (99.5%) in their view that a serious loss of biological diversity is likely, very likely, or virtually certain. Scientists' agreement that serious loss is very likely or virtually certain ranged from 72.8% for Western Europe to 90.9% for Southeast Asia. Tropical coral ecosystems were perceived as the most seriously affected by loss of biological diversity; 88.0% of respondents familiar with that ecosystem type agreed that a serious loss is very likely or virtually certain. With regard to conservation strategies, scientists most often viewed understanding how people and nature interact in certain contexts and the role of biological diversity in maintaining ecosystem function as their priorities. Protection of biological diversity for its cultural and spiritual values and because of its usefulness to humans were low priorities, which suggests that many scientists do not fully support the utilitarian concept of ecosystem services. Many scientists expressed a willingness to consider conservation triage, engage in active conservation interventions, and consider reframing conservation goals and measures of success for conservation of biological diversity in an era of climate change. Although some heterogeneity of opinion is evident, results of the survey show a clear consensus within the scientific community on core issues of the extent and geographic scope of loss of biological diversity and on elements that may contribute to successful conservation strategies in the future.     

Urban agriculture,civil interfaces and moving beyond difference: the experiences of plot holders in Dublin and Belfast

Recent literature suggests that a “shared politics of place” attained through joint activities fosters social integration and provides people with a means to practise co-operation [Baumann, G., 1996. Contesting culture: discourses of identity in multi-ethnic London. Cambridge: Cambridge University Press; Sanjek, R., 1998. The future of us all: race & neighbourhood policies in New York City. Ithaca, NY: Cornell University Press; Sennett, R., 2012. Together: the rituals, pleasures and politics of cooperation. UK: Penguin]. Such a “shared politics of place” is most likely to occur in the context of public space conceptualised broadly as “the setting for everyday spatial behaviour of individuals and communities, emphasizing ordinary activities of citizens” [Lownsbrough, H. and Beunderman, J., 2007. Equally spaced? Public space and interaction between diverse communities. London: Demos, p. 8]. Here we explore one element of such public space – urban agriculture sites – with a view to identifying the extent to which a “shared politics of place” can be created and nurtured among the cultivating citizenry. The paper draws on data collected on allotment gardening sites in two urban contexts: Dublin (Ireland) and Belfast (Northern Ireland) over the period 2009–2013. We demonstrate the centrality of allotment cultivation to the generation of solidarity, mutuality and trust among participating citizens. Individuals engaging in allotment gardening in both Dublin and Belfast create and sustain civil interfaces – dismantling barriers, exchanging knowledge, challenging stereotypes, generating empathy and getting on with the business of simply getting on with their lives. The modus operandi of allotment gardening is predicated on a willingness to disregard social and ethno-national categorisations while on site. This is not to deny that such differences exist and persist, but allotments offer a “space of potential” where those differences are, at least for a time, rendered less salient.     

Abundance and diversity of the phyllosphere bacterial communities of Mediterranean perennial plants that differ in leaf chemistry

Summary.  We studied the epiphytic bacterial communities of the summer leaves of eight perennial species naturally occurring in a Mediterranean ecosystem. The species differ in essential-oil content (from rich in essential oil to non-producers) and composition, and also in life form (from herbaceous species to tall shrubs). We compared the epiphytic bacterial communities on the basis of (i) their abundance, (ii) their metabolic profile (derived by use of the BIOLOG Ecoplate system) and (iii) richness and diversity of substrates that they use, as a measure of functional diversity. Among all species, the aromatic Melissa officinalis was the most abundantly colonized. The bacterial communities on the leaves of the aromatic Myrtus communis, Calamintha nepeta and Melissa officinalis, and also of Cistus incanus catabolized all 31 substrates offered; those on the evergreen-sclerophyllous species, Arbutus unedo and Quercus coccifera, catabolized only 14 and 17 substrates, respectively. Carbohydrates were consistently used abundantly by all communities, whereas carboxylic acids were most variably used. On average, the group of aromatic plants scored higher regarding bacterial abundance, and richness and diversity of substrates used by the bacterial communities on their leaves; the lowest values for both substrate-use indices were recorded in A. unedo. Bacterial abundance or richness or diversity of substrates used did not vary with leaf oil content. Abundance was positively correlated with both substrate-use indices. Results support claims that the antimicrobial effects of essential oils are not exerted so much under natural conditions as reports based on biassays with pathogens usually show. Although essential oils play a part in the microbial colonization of the phyllosphere, it is not likely that inhibition of phyllosphere bacteria is essential oils’ primary role, at least in the Mediterranean environment.