163 research outputs found
BIOFUELS IN THE EUROPEAN UNION
Sažetak
U Europskoj uniji (EU) okvir politike razvoja tržišta biogoriva tvori Direktiva 2003/30/EC o promicanju korištenja biogoriva ili drugih obnovljivih goriva u prometu. Ta Direktiva određuje značajni cilj od 2 % potrošnje biogoriva (po energetskom sadržaju) u 2005. godini uz porast od 0,75 % godišnje te zasad kulminira ciljem od 5,75 % u 2010. Međutim, EU je priznala da cilj potrošnje od 2 % u 2005. nije ostvaren. Ovaj prikaz stoga razmatra ključne pokretače i političke inicijative i na razini Odbora i na onoj zemalja-članica koji će utjecati na razvoj tržišta biogoriva u EU u razdoblju do 2010. godine. Nadalje se razmatraju, također, i pitanja održivosti i kakvoće goriva, koja proizlaze iz korištenja prvih biogoriva, kako bi se utvrdili pokretači uvođenja proizvoda druge generacije.Abstract
In the European Union (EU), the policy framework for the development of a biofuels market is Directive 2003/30/EC on the promotion of the use of biofuels or other renewable fuels for transport. This Directive sets an indicative target of 2% biofuel consumption (by energy content) in 2005 rising by 0.75% per annum and currently culminates in a target of 5.75% in 2010. However, the EU has acknowledged that the 2% consumption target for 2005 has not been met. This presentation therefore reviews the Key drivers and policy initiatives at both the Commission and Member State level that are influencing the development of the biofuels market in the EU in the period to 2010. In addition, sustainability and fuel quality issues arising from the use of 1st biofuels are also addressed in order to define the drivers for the introduction of 2nd generation products
Boundary manifolds of projective hypersurfaces
We study the topology of the boundary manifold of a regular neighborhood of a
complex projective hypersurface. We show that, under certain Hodge theoretic
conditions, the cohomology ring of the complement of the hypersurface
functorially determines that of the boundary. When the hypersurface defines a
hyperplane arrangement, the cohomology of the boundary is completely determined
by the combinatorics of the underlying arrangement and the ambient dimension.
We also study the LS category and topological complexity of the boundary
manifold, as well as the resonance varieties of its cohomology ring.Comment: 31 pages; accepted for publication in Advances in Mathematic
Joint analysis of stressors and ecosystem services to enhance restoration effectiveness
With increasing pressure placed on natural systems by growing human populations, both scientists and resource managers need a better understanding of the relationships between cumulative stress from human activities and valued ecosystem services. Societies often seek to mitigate threats to these services through large-scale, costly restoration projects, such as the over one billion dollar Great Lakes Restoration Initiative currently underway. To help inform these efforts, we merged high-resolution spatial analyses of environmental stressors with mapping of ecosystem services for all five Great Lakes. Cumulative ecosystem stress is highest in near-shore habitats, but also extends offshore in Lakes Erie, Ontario, and Michigan. Variation in cumulative stress is driven largely by spatial concordance among multiple stressors, indicating the importance of considering all stressors when planning restoration activities. In addition, highly stressed areas reflect numerous different combinations of stressors rather than a single suite of problems, suggesting that a detailed understanding of the stressors needing alleviation could improve restoration planning. We also find that many important areas for fisheries and recreation are subject to high stress, indicating that ecosystem degradation could be threatening key services. Current restoration efforts have targeted high-stress sites almost exclusively, but generally without knowledge of the full range of stressors affecting these locations or differences among sites in service provisioning. Our results demonstrate that joint spatial analysis of stressors and ecosystem services can provide a critical foundation for maximizing social and ecological benefits from restoration investments. www.pnas.org/lookup/suppl/doi:10.1073/pnas.1213841110/-/DCSupplementa
The left superior temporal gyrus is a shared substrate for auditory short-term memory and speech comprehension: evidence from 210 patients with stroke
Competing theories of short-term memory function make specific predictions about the functional anatomy of auditory short-term memory and its role in language comprehension. We analysed high-resolution structural magnetic resonance images from 210 stroke patients and employed a novel voxel based analysis to test the relationship between auditory short-term memory and speech comprehension. Using digit span as an index of auditory short-term memory capacity we found that the structural integrity of a posterior region of the superior temporal gyrus and sulcus predicted auditory short-term memory capacity, even when performance on a range of other measures was factored out. We show that the integrity of this region also predicts the ability to comprehend spoken sentences. Our results therefore support cognitive models that posit a shared substrate between auditory short-term memory capacity and speech comprehension ability. The method applied here will be particularly useful for modelling structure–function relationships within other complex cognitive domains
The Contribution of the Parietal Lobes to Speaking and Writing
The left parietal lobe has been proposed as a major language area. However, parietal cortical function is more usually considered in terms of the control of actions, contributing both to attention and cross-modal integration of external and reafferent sensory cues. We used positron emission tomography to study normal subjects while they overtly generated narratives, both spoken and written. The purpose was to identify the parietal contribution to the modality-specific sensorimotor control of communication, separate from amodal linguistic and memory processes involved in generating a narrative. The majority of left and right parietal activity was associated with the execution of writing under visual and somatosensory control irrespective of whether the output was a narrative or repetitive reproduction of a single grapheme. In contrast, action-related parietal activity during speech production was confined to primary somatosensory cortex. The only parietal area with a pattern of activity compatible with an amodal central role in communication was the ventral part of the left angular gyrus (AG). The results of this study indicate that the cognitive processing of language within the parietal lobe is confined to the AG and that the major contribution of parietal cortex to communication is in the sensorimotor control of writing
Copy number deletion burden is associated with cognitive, structural, and resting-state network differences in patients with schizophrenia
Total burden of copy number deletions has been implicated in schizophrenia risk and has been associated with reduced cognitive functioning. The current study aims to replicate the cognitive findings and investigate regional grey and white matter volumes. Moreover, it will explore resting-state networks for correlations between functional connectivity and total deletion burden. All imaging differences will be investigated for correlations with cognitive differences. Seventy-eight patients with chronic schizophrenia, who formed a subset of a large genome-wide association study (GWAS), were assessed for intelligence, 34 had structural magnetic resonance imaging, 33 had resting-state functional magnetic resonance imaging, and 32 had diffusion tensor imaging (DTI). Total deletion burden was negatively associated with IQ performance and positively associated with regional volumes in the striatum bilaterally and in the right superior temporal gyrus and white-matter in the corpus callosum. Correlations were identified between deletion burden and both hyper and hypoconnectivity within the default-mode network and hypoconnectivity within the cognitive control network. The functional connectivity correlations with deletion burden were also correlated with the IQ differences identified. Total deletion burden affects regional volumes and resting-state functional connectivity in key brain networks in patients with schizophrenia. Moreover, effects of deletions on cognitive functioning in may be due to inefficiency of key brain networks as identified by dysconnectivity in resting-state networks
Dynamic expression of tyrosine hydroxylase mRNA and protein in neurons of the striatum and amygdala of mice, and experimental evidence of their multiple embryonic origin
Neural correlates of verbal working memory: an fMRI meta-analysis
Verbal Working memory (vWM) capacity measures the ability to maintain and manipulate verbal information for a short period of time. The specific neural correlates of this construct are still a matter of debate. The aim of this study was to conduct a coordinate-based meta-analysis of 42 fMRI studies on visual vWM in healthy subjects (n=795, males=459, females=325, unknown=11; age range: 18-75). The studies were obtained after an exhaustive literature search on PubMed, Scopus, Web of Science, and Brainmap database. We analyzed regional activation differences during fMRI tasks with the anisotropic effect-size version of seed-based d mapping software (ES-SDM). The results were further validated by performing jackknife sensitivity analyses and heterogeneity analyses. We investigated the effect of numerous relevant influencing factors by fitting corresponding linear regression models. We isolated consistent activation in a network containing fronto-parietal areas, right cerebellum, and basal ganglia structures. Regarding lateralization, the results pointed towards a bilateral frontal activation, a left-lateralization of parietal regions and a right-lateralization of the cerebellum, indicating that the left-hemisphere concept of vWM should be reconsidered. We also isolated activation in regions important for response inhibition, emphasizing the role of attentional control in vWM. Moreover, we found a significant influence of mean reaction time, load and age on activation associated with vWM. Activation in left medial frontal gyrus, left precentral gyrus and left precentral gyrus turned out to be positively associated with mean reaction time whereas load was associated with activation across the PFC, fusiform gyrus, parietal cortex and parts of the cerebellum. In the latter case activation was mainly detectable in both hemispheres whereas the influence of age became manifest predominantly in the left hemisphere. This led us to conclude that future vWM studies should take these factors into consideration
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