246 research outputs found
Optimization of the sizing of a solar thermal electricity plant: mathematical programming versus genetic algorithms
Genetic algorithms (GAs) have been argued to constitute a flexible search thereby enabling to solve difficult problems which classical optimization methodologies may find hard to solve. This paper is intended towards this direction and show a systematic application of a GA and its modification to solve a real-world optimization problem of sizing a solar thermal electricity plant. Despite the existence of only three variables, this problem exhibits a number of other common difficulties-black-box nature of solution evaluation, massive multi-modality, wide and non-uniform range of variable values, and terribly rugged function landscape-which prohibits a classical optimization method to find even a single acceptable solution. Both GA implementations perform well and a local analysis is performed to demonstrate the optimality of obtained solutions. This study considers both classical and genetic optimization on a fairly complex yet typical real-world optimization problems and demonstrates the usefulness and future of GAs in applied optimization activities in practice
IGR J19552+0044: A new asynchronous short period polar: "Filling the gap between intermediate and ordinary polars"
Based on XMM--Newton X-ray observations IGR J19552+0044 appears to be either
a pre-polar or an asynchronous polar. We conducted follow-up optical
observations to identify the sources and periods of variability precisely and
to classify this X-ray source correctly. Extensive multicolor photometric and
medium- to high-resolution spectroscopy observations were performed and period
search codes were applied to sort out the complex variability of the object. We
found firm evidence of discording spectroscopic (81.29+/-0.01m) and photometric
(83.599+/-0.002m) periods that we ascribe to the white dwarf (WD)\ spin period
and binary orbital period, respectively. This confirms that IGR J19552+0044 is
an asynchronous polar. Wavelength-dependent variability and its continuously
changing shape point at a cyclotron emission from a magnetic WD with a
relatively low magnetic field below 20 MG.
The difference between the WD spin period and the binary orbital period
proves that IGR J19552+0044 is a polar with the largest known degree of
asynchronism (0.97 or 3%).Comment: 9 pages, 10 figures, A&A accepte
Chaperoned amyloid proteins for immune manipulation: a-Synuclein/Hsp70 shifts immunity toward a modulatory phenotype
α-Synuclein (αSyn) is a 140-residue amyloid-forming protein whose aggregation is linked to Parkinson's disease (PD). It has also been found to play a critical role in the immune imbalance that accompanies disease progression, a characteristic that has prompted the search for an effective αSyn-based immunotherapy. In this study, we have simultaneously exploited two important features of certain heat-shock proteins (HSPs): their classical âchaperoneâ activities and their recently discovered and diverse âimmunoactiveâ properties. In particular, we have explored the immune response elicited by immunization of C57BL/6 mice with an αSyn/Hsp70 protein combination in the absence of added adjuvant. Our results show differential effects for mice immunized with the αSyn/Hsp70 complex, including a restrained αSyn-specific (IgM and IgG) humoral response as well as minimized alterations in the Treg (CD4+CD25+Foxp3+) and Teff (CD4+Foxp3â) cell populations, as opposed to significant changes in mice immunized with αSyn and Hsp70 alone. Furthermore, in vitro-stimulated splenocytes from immunized mice showed the lowest relative response against αSyn challenge for the âαSyn/Hsp70â experimental group as measured by IFN-Îł and IL-17 secretion, and higher IL-10 levels when stimulated with LPS. Finally, serum levels of Th1-cytokine IFN-Îł and immunomodulatory IL-10 indicated a unique shift toward an immunomodulatory/immunoprotective phenotype in mice immunized with the αSyn/Hsp70 complex. Overall, we propose the use of functional âHSP-chaperoned amyloid/aggregating proteinsâ generated with appropriate HSP-substrate protein combinations, such as the αSyn/Hsp70 complex, as a novel strategy for immune-based intervention against synucleinopathies and other amyloid or âmisfoldingâ neurodegenerative disorders.España, Ministerio de EconomĂa y Competitividad SAF-2012/39720Junta de AndalucĂa P10-CTS-6928Junta de AndalucĂa P11-CTS-816
White matter injury restoration after stem cell administration in subcortical ischemic stroke
This is an Open Access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Introduction]: An animal model of subcortical ischemic stroke with white matter affectation was induced in rats by injection of endothelin-1. At 24 hours, 2 Ă 10 6 ADMSC were administered intravenously to the treatment group. Functional evaluation, lesion size, fiber tract integrity, cell death, proliferation, white matter repair markers (Olig-2, NF, and MBP) and NogoA were all studied after sacrifice (7 days and 28 days). ADMSC migration and implantation in the brain as well as proteomics analysis and functions of the secretome were also analyzed. [Results]: Neither ADMSC migration nor implantation to the brain was observed after ADMSC administration. In contrast, ADMSC implantation was detected in peripheral organs. The treatment group showed a smaller functional deficit, smaller lesion area, less cell death, more oligodendrocyte proliferation, more white matter connectivity and higher amounts of myelin formation. The treated animals also showed higher levels of white matter-associated markers in the injured area than the control group. Proteomics analysis of the ADMSC secretome identified 2,416 proteins, not all of them previously described to be involved in brain plasticity. [Conclusions]: White matter integrity in subcortical stroke is in part restored by ADMSC treatment; this is mediated by repair molecular factors implicated in axonal sprouting, remyelination and oligodendrogenesis. These findings are associated with improved functional recovery after stroke.This study was supported by research grants PS12/01754, PI11/00909 and INVICTUS (RD12/0014) (Spanish Neurovascular Network), SAF2010-37926, ProteoRed-PT13/0001/0017 and a Sara Borrell postdoctoral fellowship (CD12/00706, to LOO) from Research Institute Carlos III, Ministry of Science and Innovation of Spain. Furthermore, TS (CP12/03121) and FC (CP14/00154) are recipients of a research contract from Miguel Servet Program of Instituto de Salud Carlos III-Peer Reviewe
Chaperoned amyloid proteins for immune manipulation: A-synuclein/hsp70 shifts immunity toward a modulatory phenotype
a-Synuclein (aSyn) is a 140-residue amyloid-forming protein whose aggregation is linked to Parkinsonâs disease (PD). It has also been found to play a critical role in the immune imbalance that accompanies disease progression, a characteristic that has prompted the search for an effective aSyn-based immunotherapy. In this study, we have simultaneously exploited two important features of certain heat-shock proteins (HSPs): their classical ââchaperoneââ activities and their recently discovered and diverse ââimmunoactiveââ properties. In particular, we have explored the immune response elicited by immunization of C57BL/6 mice with an aSyn/Hsp70 protein combination in the absence of added adjuvant. Our results show differential effects for mice immunized with the aSyn/Hsp70 complex, including a restrained aSyn-specific (IgM and IgG) humoral response as well as minimized alterations in the Treg (CD4 CD25 Foxp3 ) and Teff (CD4 Foxp3 ) cell populations, as opposed to significant changes in mice immunized with aSyn and Hsp70 alone. Furthermore, in vitro-stimulated splenocytes from immunized mice showed the lowest relative response against aSyn challenge for the ââaSyn/Hsp70ââ experimental group as measured by IFN-g and IL-17 secretion, and higher IL-10 levels when stimulated with LPS. Finally, serum levels of Th1-cytokine IFN-g and immunomodulatory IL-10 indicated a unique shift toward an immunomodulato-ry/immunoprotective phenotype in mice immunized with the aSyn/Hsp70 complex. Overall, we propose the use of functional ââHSP-chaperoned amyloid/ aggregating proteinsââ generated with appropriate HSP-substrate protein combinations, such as the aSyn/Hsp70 complex, as a novel strategy for immune-based intervention against synucleinopathies and other amyloid or ââmisfoldingââ neurodegenerative disorders.Financial support was provided by the Carlos III Institute
of Health of Spain (Spanish Ministry of Economy and
Competitiveness) according to the Strategic Action in
Health (CP10/00527 to CR; PI14-01600 to DP) with
co-funding by FEDER funds, the Spanish Ministry of
Economy and Competitiveness (SAF-2012/39720 to CR),
the Andalusian Ministry of Economy, Science and Innovation
(P10-CTS-6928 and P11-CTS-8161 to DP) and the
PAIDI Program from the Andalusian Government (CTS-
677 to DP). ALG holds a FPU Predoctoral Fellowship from
the Spanish Ministry of Education (AP-2009/3816). The
works of EJDG and CMD are supported by the Wellcome
Trust, and the UK Medical, and Biotechnological and
Biological Sciences Research Councils
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