566 research outputs found
A Paper at the ECE Symposium on Application of Economic-Mathematical Models in the Energy Sector, Alma-Ata September 1973
The energy sector of each country is a part of the national economic subsystems which directly and to a considerable degree has an influence on the growth rate of the national economy and the increase of national income. Therefore it is a permanent objective to always provide a rational basis for the provision of society with demand-determined supply of energy sources. A tool for the proper achievement of this goal is the application of mathematical-economic models for optimization of the energy sector with consideration of national economic constraints. It is in the interest of society to include the largest possible system in the optimization models. According to the current condition of our understanding, that type of objective can be achieved only with mathematical-economic system models which consider all essential economic, technological, technical, parameters, and to a limited degree also political-economic influences
Reversing A beta Fibrillation and Inhibiting A beta Primary Neuronal Cell Toxicity Using Amphiphilic Polyphenylene Dendrons
Polymer Structures on Surface Acoustic Wave Biosensors
The influence of surface structuring on surface acoustic wave (SAW) biosensor signals has been investigated. Polymer structures on the sensor surfaces were applied by lithography or by self-assembling of polystyrene microparticles. In first experiments, structured and unstructured sensors led to similar results in a model affinity assay using streptavidin and biotinylated protein. On the other hand, structuring had a strong effect on SAW sensor signals obtained by protein adsorption on parylene C coated sensors. Depending on the protein, both decreased (albumin, streptavidin) and increased (fibrinogen) signals were observed with structured SAW sensors. Particularly the latter could contribute to facilitated blood analysis in the future
Limited sensitivity and specificity of the ACR/EULAR-2019 classification criteria for SLE in JSLE?—observations from the UK JSLE Cohort Study
Objectives:
This study aimed to test the performance of the new ACR and EULAR criteria, that include ANA positivity as entry criterion, in JSLE. /
Methods:
Performance of the ACR/EULAR-2019 criteria were compared with Systemic Lupus International Collaborating Clinics (SLICC-2012), using data from children and young people (CYP) in the UK JSLE Cohort Study (n = 482), with the ACR-1997 criteria used as reference standard. An unselected cohort of CYP positive for ANA (n = 129) was used to calculate positive/negative predictive values of the criteria. /
Results:
At both first and last visits, the number of patients fulfilling the different classification criteria varied significantly (P < 0.001). The sensitivity of the SLICC-2012 criteria was higher when compared with that of the ACR/EULAR-2019 criteria at first and last visits (98% vs 94% for first visit, and 98% vs 96% for last visit; P < 0.001), when all available CYP were considered. The ACR/EULAR-2019 criteria were more specific when compared with the SLICC-2012 criteria (77% vs 67% for first visit, and 81% vs 71% for last visit; P < 0.001). Significant differences between the classification criteria were mainly caused by the variation in ANA positivity across ages. In the unselected cohort of ANA-positive CYP, the ACR/EULAR-2019 criteria produced the highest false-positive classification (6/129, 5%). /
Conclusion:
In CYP, the ACR/EULAR-2019 criteria are not superior to those of the SLICC-2012 or ACR-1997 criteria. If classification criteria are designed to include CYP and adult populations, paediatric rheumatologists should be included in the consensus and evaluation process, as seemingly minor changes can significantly affect outcomes
Energy/Environment Models: Relationship to Planning in Wisconsin, GDR, Rhone Alps
This report is a description and cross-regional comparison of the institutional structures and modeling methodologies of the three regions participating in the IIASA Research Program on Management of Regional Energy/Environment Systems. Descriptions are presented for the state of Wisconsin (USA), the German Democratic Republic, and the Rhone-Alpes Region (France), by specialists and policy makers from the respective regions. These descriptions demonstrate quite vividly the relationships between the institutional structure of a region and its use of models and planning tools
Neuropsychiatric involvement in juvenile-onset systemic lupus erythematosus: Data from the UK Juvenile-onset systemic lupus erythematosus cohort study
INTRODUCTION: Juvenile-onset systemic lupus erythematosus (JSLE) is a rare autoimmune/inflammatory disease with significant morbidity and mortality. Neuropsychiatric (NP) involvement is a severe complication, encompassing a heterogeneous range of neurological and psychiatric manifestations. METHODS: Demographic, clinical, and laboratory features of NP-SLE were assessed in participants of the UK JSLE Cohort Study, and compared to patients in the same cohort without NP manifestations. RESULTS: A total of 428 JSLE patients were included in this study, 25% of which exhibited NP features, half of them at first visit. Most common neurological symptoms among NP-JSLE patients included headaches (78.5%), mood disorders (48.6%), cognitive impairment (42%), anxiety (23.3%), seizures (19.6%), movement disorders (17.7%), and cerebrovascular disease (14.9%). Peripheral nervous system involvement was recorded in 7% of NP-SLE patients. NP-JSLE patients more frequently exhibited thrombocytopenia (<100 Ă— 109/L) (p = 0.04), higher C-reactive protein levels (p = 0.01), higher global pBILAG score at first visit (p < 0.001), and higher SLICC damage index score at first (p = 0.02) and last (p < 0.001) visit when compared to JSLE patients without NP involvement. CONCLUSIONS: A significant proportion of JSLE patients experience NP involvement (25%). Juvenile-onset NP-SLE most commonly affects the CNS and is associated with increased overall disease activity and damage
AtALMT12 represents an R-type anion channel required for stomatal movement in Arabidopsis guard cells
Stomatal pores formed by a pair of guard cells in the leaf epidermis control gas exchange and transpirational water loss. Stomatal closure is mediated by the release of potassium and anions from guard cells. Anion efflux from guard cells involves slow (S-type) and rapid (R-type) anion channels. Recently the SLAC1 gene has been shown to encode the slow, voltage-independent anion channel component in guard cells. In contrast, the R-type channel still awaits identification. Here, we show that AtALMT12, a member of the aluminum activated malate transporter family in Arabidopsis, represents a guard cell R-type anion channel. AtALMT12 is highly expressed in guard cells and is targeted to the plasma membrane. Plants lacking AtALMT12 are impaired in dark- and COâ‚‚ -induced stomatal closure, as well as in response to the drought-stress hormone abscisic acid. Patch-clamp studies on guard cell protoplasts isolated from atalmt12 mutants revealed reduced R-type currents compared with wild-type plants when malate is present in the bath media. Following expression of AtALMT12 in Xenopus oocytes, voltage-dependent anion currents reminiscent to R-type channels could be activated. In line with the features of the R-type channel, the activity of heterologously expressed AtALMT12 depends on extracellular malate. Thereby this key metabolite and osmolite of guard cells shifts the threshold for voltage activation of AtALMT12 towards more hyperpolarized potentials. R-Type channels, like voltage-dependent cation channels in nerve cells, are capable of transiently depolarizing guard cells, and thus could trigger membrane potential oscillations, action potentials and initiate long-term anion and K(+) efflux via SLAC1 and GORK, respectively
Is the Multiverse Hypothesis capable of explaining the Fine Tuning of Nature Laws and Constants? The Case of Cellular Automata
The objective of this paper is analyzing to which extent the multiverse
hypothesis provides a real explanation of the peculiarities of the laws and
constants in our universe. First we argue in favor of the thesis that all
multiverses except Tegmark's > are too small to
explain the fine tuning, so that they merely shift the problem up one level.
But the > is surely too large. To prove this
assessment, we have performed a number of experiments with cellular automata of
complex behavior, which can be considered as universes in the mathematical
multiverse. The analogy between what happens in some automata (in particular
Conway's >) and the real world is very strong. But if the
results of our experiments can be extrapolated to our universe, we should
expect to inhabit -- in the context of the multiverse -- a world in which at
least some of the laws and constants of nature should show a certain time
dependence. Actually, the probability of our existence in a world such as ours
would be mathematically equal to zero. In consequence, the results presented in
this paper can be considered as an inkling that the hypothesis of the
multiverse, whatever its type, does not offer an adequate explanation for the
peculiarities of the physical laws in our world. A slightly reduced version of
this paper has been published in the Journal for General Philosophy of Science,
Springer, March 2013, DOI: 10.1007/s10838-013-9215-7.Comment: 30 pages, 16 figures, 5 tables. Slightly reduced version published in
Journal for General Philosophy of Scienc
Calcium sensor kinase activates potassium uptake systems in gland cells of Venus flytraps
The Darwin plant Dionaea muscipula is able to grow on mineral-poor soil, because it gains essential nutrients from captured animal prey. Given that no nutrients remain in the trap when it opens after the consumption of an animal meal, we here asked the question of how Dionaea sequesters prey-derived potassium. We show that prey capture triggers expression of a K+ uptake system in the Venus flytrap. In search of K+ transporters endowed with adequate properties for this role, we screened a Dionaea expressed sequence tag (EST) database and identified DmKT1 and DmHAK5 as candidates. On insect and touch hormone stimulation, the number of transcripts of these transporters increased in flytraps. After cRNA injection of K+-transporter genes into Xenopus oocytes, however, both putative K+ transporters remained silent. Assuming that calcium sensor kinases are regulating Arabidopsis K+ transporter 1 (AKT1), we coexpressed the putative K+ transporters with a large set of kinases and identified the CBL9-CIPK23 pair as the major activating complex for both transporters in Dionaea K+ uptake. DmKT1 was found to be a K+-selective channel of voltage-dependent high capacity and low affinity, whereas DmHAK5 was identified as the first, to our knowledge, proton-driven, high-affinity potassium transporter with weak selectivity. When the Venus flytrap is processing its prey, the gland cell membrane potential is maintained around -120 mV, and the apoplast is acidified to pH 3. These conditions in the green stomach formed by the closed flytrap allow DmKT1 and DmHAK5 to acquire prey-derived K+, reducing its concentration from millimolar levels down to trace levels
- …