56 research outputs found
The Effect of Childhood Conduct Disorder on Human Capital
This paper estimates the longer-term effects of childhood conduct disorder on human capital accumulation and violent and criminal behaviour later in life using data of Australian twins. We measure conduct disorder with a rich set of indicators based on diagnostic criteria from psychiatry. Using ordinary least squares (OLS) and twin fixed effects (FE) estimation approaches, we find that early (pre-18) conduct disorder problems significantly affect both human capital accumulation and violent and criminal behaviour over the life course. In addition, we find that conduct disorder is more deleterious if these behaviours occur earlier in life.conduct disorder, human capital, twins
Material flow enhancement in production assembly lines under application of zoned order picking systems
Introduced research work relates to the possibility of material flow enhancement in production systems, with the apostrophe on material order picking in production assembly lines. The paper presents basic rules and the results related to formed computer models of zoned order picking systems under the application of developed bound cavities method
The effect of childhood conduct disorder on human capital
This paper estimates the longer-term effects of childhood conduct disorder on human capital accumulation and violent and criminal behaviour later in life using data of Australian twins. We measure conduct disorder with a rich set of indicators based on diagnostic criteria from psychiatry. Using ordinary least squares (OLS) and twin fixed effects (FE) estimation approaches, we find that early (pre-18) conduct disorder problems significantly affect both human capital accumulation and violent and criminal behaviour over the life course. In addition, we find that conduct disorder is more deleterious if these behaviours occur earlier in life
Influence of ambience temperature and operational-constructive parameters on landfill gas generation - Case study Novi Sad
Researches in the area of landfill gas generation and energy utilization are currently underway and widespread in the world for several reasons: reducing effects of greenhouse gases, possibilities for utilizing alternative energy sources, reducing conventional energy resources exploitation, and environmental protection. First part of this research is conducted with an aim to establish the influence of meteorological parameters, primarily ambience temperature, on the methane generation processes at Novi Sad landfill. The second part of the research refers to functional characteristics of landfill such as the waste age, closing practice, and the age of certain parts of landfill body, as well as the waste depth and quantity of generated methane. Based on several years of investigation, it is concluded that methane generation varies in the range of 0-34 vol. % m3/m3, and that seasonal variations have significant influence on methane generation. At low temperatures, during winter, methane generation and migration is stagnant while in summer periods, due to higher temperatures, the process of methane generation is more intensive
Systems analysis of iron metabolism: the network of iron pools and fluxes
<p>Abstract</p> <p>Background</p> <p>Every cell of the mammalian organism needs iron as trace element in numerous oxido-reductive processes as well as for transport and storage of oxygen. The very versatility of ionic iron makes it a toxic entity which can catalyze the production of radicals that damage vital membranous and macromolecular assemblies in the cell. The mammalian organism maintains therefore a complex regulatory network of iron uptake, excretion and intra-body distribution. Intracellular regulation in different cell types is intertwined with a global hormonal signalling structure. Iron deficiency as well as excess of iron are frequent and serious human disorders. They can affect every cell, but also the organism as a whole.</p> <p>Results</p> <p>Here, we present a kinematic model of the dynamic system of iron pools and fluxes. It is based on ferrokinetic data and chemical measurements in C57BL6 wild-type mice maintained on iron-deficient, iron-adequate, or iron-loaded diet. The tracer iron levels in major tissues and organs (16 compartment) were followed for 28 days. The evaluation resulted in a whole-body model of fractional clearance rates. The analysis permits calculation of absolute flux rates in the steady-state, of iron distribution into different organs, of tracer-accessible pool sizes and of residence times of iron in the different compartments in response to three states of iron-repletion induced by the dietary regime.</p> <p>Conclusions</p> <p>This mathematical model presents a comprehensive physiological picture of mice under three different diets with varying iron contents. The quantitative results reflect systemic properties of iron metabolism: dynamic closedness, hierarchy of time scales, switch-over response and dynamics of iron storage in parenchymal organs.</p> <p>Therefore, we could assess which parameters will change under dietary perturbations and study in quantitative terms when those changes take place.</p
Morphology and density of post-CME current sheets
Eruption of a coronal mass ejection (CME) drags and "opens" the coronal
magnetic field, presumably leading to the formation of a large-scale current
sheet and the field relaxation by magnetic reconnection. We analyze physical
characteristics of ray-like coronal features formed in the aftermath of CMEs,
to check if the interpretation of this phenomenon in terms of reconnecting
current sheet is consistent with the observations. The study is focused on
measurements of the ray width, density excess, and coronal velocity field as a
function of the radial distance. The morphology of rays indicates that they
occur as a consequence of Petschek-like reconnection in the large scale current
sheet formed in the wake of CME. The hypothesis is supported by the flow
pattern, often showing outflows along the ray, and sometimes also inflows into
the ray. The inferred inflow velocities range from 3 to 30 km s,
consistent with the narrow opening-angle of rays, adding up to a few degrees.
The density of rays is an order of magnitude larger than in the ambient corona.
The density-excess measurements are compared with the results of the analytical
model in which the Petschek-like reconnection geometry is applied to the
vertical current sheet, taking into account the decrease of the external
coronal density and magnetic field with height. The model results are
consistent with the observations, revealing that the main cause of the density
excess in rays is a transport of the dense plasma from lower to larger heights
by the reconnection outflow
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Developing European conservation and mitigation tools for pollination services: approaches of the STEP (Status and Trends of European Pollinators) project
Pollinating insects form a key component of European biodiversity, and provide a vital ecosystem service to crops and wild plants. There is growing evidence of declines in both wild and domesticated pollinators, and parallel declines in plants relying upon them. The STEP project (Status and Trends of European Pollinators, 2010-2015, www.stepproject.net) is documenting critical elements in the nature and extent of these declines, examining key functional traits associated with pollination deficits, and developing a Red List for some European pollinator groups. Together these activities are laying the groundwork for future pollinator monitoring programmes. STEP is also assessing the relative importance of potential drivers of pollinator declines, including climate change, habitat loss and fragmentation, agrochemicals, pathogens, alien species, light pollution, and their interactions. We are measuring the ecological and economic impacts of declining pollinator services and floral resources, including effects on wild plant populations, crop production and human nutrition. STEP is reviewing existing and potential mitigation options, and providing novel tests of their effectiveness across Europe. Our work is building upon existing and newly developed datasets and models, complemented by spatially-replicated campaigns of field research to fill gaps in current knowledge. Findings are being integrated into a policy-relevant framework to create evidence-based decision support tools. STEP is establishing communication links to a wide range of stakeholders across Europe and beyond, including policy makers, beekeepers, farmers, academics and the general public. Taken together, the STEP research programme aims to improve our understanding of the nature, causes, consequences and potential mitigation of declines in pollination services at local, national, continental and global scales
Mass-flowering crops dilute pollinator abundance in agricultural landscapes across Europe
Mass-flowering crops (MFCs) are increasingly cultivated and might influence pollinator communities in MFC fields and nearby semi-natural habitats (SNHs). Across six European regions and 2 years, we assessed how landscape-scale cover of MFCs affected pollinator densities in 408 MFC fields and adjacent SNHs. In MFC fields, densities of bumblebees, solitary bees, managed honeybees and hoverflies were negatively related to the cover of MFCs in the landscape. In SNHs, densities of bumblebees declined with increasing cover of MFCs but densities of honeybees increased. The densities of all pollinators were generally unrelated to the cover of SNHs in the landscape. Although MFC fields apparently attracted pollinators from SNHs, in landscapes with large areas of MFCs they became diluted. The resulting lower densities might negatively affect yields of pollinator-dependent crops and the reproductive success of wild plants. An expansion of MFCs needs to be accompanied by pollinator-supporting practices in agricultural landscapes
Insect threats and conservation through the lens of global experts
While several recent studies have focused on global insect population trends, all are limited in either space or taxonomic scope. As global monitoring programs for insects are currently not implemented, inherent biases exist within most data. Expert opinion, which is often widely available, proves to be a valuable tool where hard data are limited. Our aim is to use global expert opinion to provide insights on the root causes of potential insect declines worldwide, as well as on effective conservation strategies that could mitigate insect biodiversity loss. We obtained 753 responses from 413 respondents with a wide variety of spatial and taxonomic expertise. The most relevant threats identified through the survey were agriculture and climate change, followed by pollution, while land management and land protection were recognized as the most significant conservation measures. Nevertheless, there were differences across regions and insect groups, reflecting the variability within the most diverse class of eukaryotic organisms on our planet. Lack of answers for certain biogeographic regions or taxa also reflects the need for research in less investigated settings. Our results provide a novel step toward understanding global threats and conservation measures for insects.Peer reviewe
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