1,243 research outputs found
Dynamic multilevel modelling of industrial energy demand in Europe
Previous studies of industry level energy demand have not accounted for the hierarchical nesting of industries within a system that also adequately allows for country specific determinants of energy demand. The principal contribution of this paper is therefore to analyse energy demand for European industries over the period 1995â2009 using a dynamic multilevel model that accounts for this hierarchical data structure. Among other things, we find, firstly, that our dynamic multilevel model suggests that if industry income and the industry energy price increase by 10%, long run energy demand will increase by 8.1% and fall by 6.8%, respectively. Secondly, we find that the corresponding long run income and price elasticities are substantially larger in a standard dynamic model of industry level energy demand which does not account for the hierarchical data structure. Our results therefore suggest that not accounting for the hierarchical data structure results in unreliable estimates of energy demand elasticities. From a policy perspective we argue that it is imperative that future industry level energy demand studies account for the hierarchical structure of the data. This is to prevent energy policy making being based on industry level evidence that substantially inflates the responsiveness of long run energy demand to income and price changes
Edge orientation signals in tactile afferents of macaques
The orientation of edges indented into the skin has been shown to be encoded in the responses of neurons in primary somatosensory cortex in a manner that draws remarkable analogies to their counterparts in primary visual cortex. According to the classical view, orientation tuning arises from the integration of untuned input from thalamic neurons with aligned but spatially displaced receptive fields (RFs). In a recent microneurography study with human subjects, the precise temporal structure of the responses of individual mechanoreceptive afferents to scanned edges was found to carry information about their orientation. This putative mechanism could in principle contribute to or complement the classical rate-based code for orientation. In the present study, we further examine orientation information carried by mechanoreceptive afferents of Rhesus monkeys. To this end, we record the activity evoked in cutaneous mechanoreceptive afferents when edges are indented into or scanned across the skin. First, we confirm that information about the edge orientation can be extracted from the temporal patterning in afferent responses of monkeys, as is the case in humans. Second, we find that while the coarse temporal profile of the response can be predicted linearly from the layout of the RF, the fine temporal profile cannot. Finally, we show that orientation signals in tactile afferents are often highly dependent on stimulus features other than orientation, which complicates putative decoding strategies. We discuss the challenges associated with establishing a neural code at the somatosensory periphery, where afferents are exquisitely sensitive and nearly deterministic
Maternal effects on anogenital distance in a wild marmot population
Peer reviewedPublisher PD
Long-wavelength approximation for string cosmology with barotropic perfect fluid
The field equations derived from the low energy string effective action with
a matter tensor describing a perfect fluid with a barotropic equation of state
are solved iteratively using the long-wavelength approximation, i.e. the field
equations are expanded by the number of spatial gradients. In the zero order, a
quasi-isotropic solution is presented and compared with the general solution of
the pure dilaton gravity. Possible cosmological models are analyzed from the
point of view of the pre-big bang scenario. The second order solutions are
found and their growing and decaying parts are studied.Comment: 19 pages, 1 figur
Carbon in the Moon
International audienceThe Moon was once thought to be depleted in volatile elements. Analyses of the carbon contents of lunar volcanic glasses reveal that carbon monoxide degassing could have produced the fire-fountain eruptions from which these glasses were formed
Recurrent gross mutations of the PTEN tumor suppressor gene in breast cancers with deficient DSB repair
Basal-like breast cancer (BBC) is a subtype of breast cancer with poor prognosis. Inherited mutations of BRCA1, a cancer susceptibility gene involved in double-strand DNA break (DSB) repair, lead to breast cancers that are nearly always of the BBC subtype; however, the precise molecular lesions and oncogenic consequences of BRCA1 dysfunction are poorly understood. Here we show that heterozygous inactivation of the tumor suppressor gene Pten leads to the formation of basal-like mammary tumors in mice, and that loss of PTEN expression is significantly associated with the BBC subtype in human sporadic and BRCA1-associated hereditary breast cancers. In addition, we identify frequent gross PTEN mutations, involving intragenic chromosome breaks, inversions, deletions and micro copy number aberrations, specifically in BRCA1-deficient tumors. These data provide an example of a specific and recurrent oncogenic consequence of BRCA1-dependent dysfunction in DNA repair and provide insight into the pathogenesis of BBC with therapeutic implications. These findings also argue that obtaining an accurate census of genes mutated in cancer will require a systematic examination for gross gene rearrangements, particularly in tumors with deficient DSB repair
Reproducibility in high-throughput density functional theory: a comparison of AFLOW, Materials Project, and OQMD
A central challenge in high throughput density functional theory (HT-DFT)
calculations is selecting a combination of input parameters and post-processing
techniques that can be used across all materials classes, while also managing
accuracy-cost tradeoffs. To investigate the effects of these parameter choices,
we consolidate three large HT-DFT databases: Automatic-FLOW (AFLOW), the
Materials Project (MP), and the Open Quantum Materials Database (OQMD), and
compare reported properties across each pair of databases for materials
calculated using the same initial crystal structure. We find that HT-DFT
formation energies and volumes are generally more reproducible than band gaps
and total magnetizations; for instance, a notable fraction of records disagree
on whether a material is metallic (up to 7%) or magnetic (up to 15%). The
variance between calculated properties is as high as 0.105 eV/atom (median
relative absolute difference, or MRAD, of 6%) for formation energy, 0.65
{\AA}/atom (MRAD of 4%) for volume, 0.21 eV (MRAD of 9%) for band gap, and
0.15 /formula unit (MRAD of 8%) for total magnetization,
comparable to the differences between DFT and experiment. We trace some of the
larger discrepancies to choices involving pseudopotentials, the DFT+U
formalism, and elemental reference states, and argue that further
standardization of HT-DFT would be beneficial to reproducibility.Comment: Authors VIH and CKHB contributed equally to this wor
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