1,121 research outputs found
Епоха "пост": людина в перспективі "нової духовності"
Розглянуто основні проблеми сучасного суспільства, пов’язані із антропологічною кризою, кардинальними змінами у темпоральності, способі буття людини. Проаналізовано ситуацію заміни попередніх гуманістичних ціннісних систем на більш “технізовані”, що призводить до виникнення нового типу людини – “постлюдини”. Посилюється вплив на людей “світу віртуальної реальності”. Нове штучне середовище “сканує”, приймає лише інформаційний аспект людини, вводячи її як цілісну істоту в стан кризи. Доведено актуальність відповідей на смислові запитання епохи, пов’язані із світоглядом, духовністю та цінностями.The main problems of modern society, related to the anthropological crisis, fundamental changes in temporality, ways of human being are considered. There is an analysis of situation of replacing the previous humanistic value systems on a more “technicized”, which causes a new type of man – “posthuman”. The impact on “the world of virtual reality” people is growing. New artifi cial environment “scans”, takes only informational aspect of human, introducing it as complete being in a state of crisis. The urgency of responses to semantic question of the epoch, related to the outlook, spirituality and values is justifi ed
On the photometric variability of blue supergiants in NGC 300 and its impact on the Flux-weighted Gravity-Luminosity Relationship
We present a study of the photometric variability of spectroscopically
confirmed supergiants in NGC 300, comprising 28 epochs extending over a period
of five months. We find 15 clearly photometrically variable blue supergiants in
a sample of nearly 70 such stars, showing maximum light amplitudes ranging from
0.08 to 0.23 magnitudes in the V band, and one variable red supergiant. We show
their light curves, and determine semi-periods for two A2 Ia stars. Assuming
that the observed changes correspond to similar variations in the bolometric
luminosity, we test for the influence of this variability on the Flux-weighted
Gravity--Luminosity Relationship and find a negligible effect, showing that the
calibration of this relationship, which has the potential to measure
extragalactic distances at the Cepheid accuracy level, is not affected by the
stellar photometric variability in any significant way.Comment: 9 pages, 3 figures, 3 tables. Accepted for publication in the
Astrophysical Journa
Remaking Urban Segregation: Processes of Income Sorting and Neighbourhood Change
ABSTRACT Segregation studies have mainly focused on urban structures as a whole or have discussed specific (gentrifying or renewing) neighbourhoods. The literature suggests that changes in segregation occur primarily through selective migration. In this paper, we follow up on recent work that has questioned these orthodoxies, suggesting that in situ social mobility, and entries to and exits from the city population should be taken into account as well, and that dynamics in all neighbourhoods should be considered. The paper traces the processes by which segregation changes for the cities of Amsterdam and The Hague for 1999-2006, using a longitudinal individuallevel database covering the entire population. It extends previous work by looking at income rather than socio-economic status and by drilling down to the neighbourhood level. Applying an existing measure of segregation (Delta) in a novel way, the analysis focuses on changes in the spatial distribution of household income, measuring the relative contribution of a range of processes to changes in segregation. Results show that segregation rises in both cities but that different processes drive changes in each case. Furthermore, the aggregate change in segregation for each city masks a diversity of changes at the neighbourhood level, some of which tend to increase segregation while others tend to reduce it. Mapping these changes and the individual processes contributing to them shows that they have a distinct geography, which seems to be structured by historically specific trends in state and housing market context
Dose Reduction in Coronary Artery Calcium Scoring Using Mono-Energetic Images from Reduced Tube Voltage Dual-Source Photon-Counting CT Data:A Dynamic Phantom Study
In order to assess coronary artery calcium (CAC) quantification reproducibility for photon-counting computed tomography (PCCT) at reduced tube potential, an anthropomorphic thorax phantom with low-, medium-, and high-density CAC inserts was scanned with PCCT (NAEOTOM Alpha, Siemens Healthineers) at two heart rates: 0 and 60–75 beats per minute (bpm). Five imaging protocols were used: 120 kVp standard dose (IQ level 16, reference), 90 kVp at standard (IQ level 16), 75% and 45% dose and tin-filtered 100 kVp at standard dose (IQ level 16). Each scan was repeated five times. Images were reconstructed using monoE reconstruction at 70 keV. For each heart rate, CAC values, quantified as Agatston scores, were compared with the reference, whereby deviations >10% were deemed clinically relevant. Reference protocol radiation dose (as volumetric CT dose index) was 4.06 mGy. Radiation dose was reduced by 27%, 44%, 67%, and 46% for the 90 kVp standard dose, 90 kVp 75% dose, 90 kVp 45% dose, and Sn100 standard dose protocol, respectively. For the low-density CAC, all reduced tube current protocols resulted in clinically relevant differences with the reference. For the medium- and high-density CAC, the implemented 90 kVp protocols and heart rates revealed no clinically relevant differences in Agatston score based on 95% confidence intervals. In conclusion, PCCT allows for reproducible Agatston scores at a reduced tube voltage of 90 kVp with radiation dose reductions up to 67% for medium- and high-density CAC
V2368 Oph: An eclipsing and double-lined spectroscopic binary used as a photometric comparison star for U Oph
The A-type star HR 6412 = V2368 Oph was used by several investigators as a
photometric comparison star for the known eclipsing binary U Oph but was found
to be variable by three independent groups, including us. By analysing series
of new spectral and photometric observations and a critical compilation of
available radial velocities, we were able to find the correct period of light
and radial-velocity variations and demonstrate that the object is an eclipsing
and double-lined spectroscopic binary moving in a highly eccentric orbit. We
derived a linear ephemeris T min.I = HJD (2454294.67 +/- 0.01) + (38.32712 +/-
0.00004)d x E and estimated preliminary basic physical properties of the
binary. The dereddened UBV magnitudes and effective temperatures of the primary
and secondary, based on our light- and velocity-curve solutions, led to
distance estimates that agree with the Hipparcos distance within the errors. We
find that the mass ratio must be close to one, but the limited number and
wavelength range of our current spectra does not allow a truly precise
determination of the binary masses. Nevertheless, our results show convincingly
that both binary components are evolved away from the main sequence, which
makes this system astrophysically very important. There are only a few
similarly evolved A-type stars among known eclipsing binaries. Future
systematic observations and careful analyses can provide very stringent tests
for the stellar evolutionary theory.Comment: 10 pages, 7 figs, in press 2011 A&
Human plasma phospholipid transfer protein increases the antiatherogenic potential of high density lipoproteins in transgenic mice
Plasma phospholipid transfer protein (PLTP) transfers phospholipids
between lipoprotein particles and alters high density lipoprotein (HDL)
subfraction patterns in vitro, but its physiological function is poorly
understood. Transgenic mice that overexpress human PLTP were generated.
Compared with wild-type mice, these mice show a 2.5- to 4.5-fold increase
in PLTP activity in plasma. This results in a 30% to 40% decrease of
plasma levels of HDL cholesterol. Incubation of plasma from transgenic
animals at 37 degrees C reveals a 2- to 3-fold increase in the formation
of pre-beta-HDL compared with plasma from wild-type mice. Although
pre-beta-HDL is normally a minor subfraction of HDL, it is known to be a
very efficient acceptor of peripheral cell cholesterol and a key mediator
in reverse cholesterol transport. Further experiments show that plasma
from transgenic animals is much more efficient in preventing the
accumulation of intracellular cholesterol in macrophages than plasma from
wild-type mice, despite lower total HDL concentrations. It is concluded
that PLTP can act as an antiatherogenic factor preventing cellular
cholesterol overload by generation of pre-beta-HDL
Toe berm design for very shallow waters on steep sea bottoms
The toe berm is a relevant design element when rubble mound breakwaters are built on steep sea bottoms in breaking conditions. Different design formulas can be found in the literature to predict the damage caused to submerged toe berms placed on gentle bottom slopes. However, these formulas are not valid for very shallow waters in combination with steep sea bottoms where toe berms receive the full force of breaking waves. To guarantee breakwater stability in these conditions, new design formulas are needed for toe berms. To this end, physical model tests were carried out and data were analyzed to characterize rock toe berm stability in very shallow water and with a bottom slope m = 1/10. Based on test results, a new formula was developed with three parameters to estimate the nominal diameter (Dn50) of the toe berm rocks: water depth at the toe (hs), deep water significant wave height (Hs0), and deep water wave length (L0p).The first author was financially supported through the FPU program (Formacion del Profesorado Universitario) funded by the Spanish Ministry of Education (Ministerio de Educacion, Cultura y Deporte) FPU13/01872. The authors also acknowledge financial support from the Spanish Ministry of Economy and Competitiveness (grant BIA2012-33967). The authors thank Debra Westall for revising the manuscript.Herrera Gamboa, MP.; Medina Folgado, JR. (2015). Toe berm design for very shallow waters on steep sea bottoms. Coastal Engineering. 103:67-77. https://doi.org/10.1016/j.coastaleng.2015.06.005S677710
Optimization by Quantum Annealing: Lessons from hard 3-SAT cases
The Path Integral Monte Carlo simulated Quantum Annealing algorithm is
applied to the optimization of a large hard instance of the Random 3-SAT
Problem (N=10000). The dynamical behavior of the quantum and the classical
annealing are compared, showing important qualitative differences in the way of
exploring the complex energy landscape of the combinatorial optimization
problem. At variance with the results obtained for the Ising spin glass and for
the Traveling Salesman Problem, in the present case the linear-schedule Quantum
Annealing performance is definitely worse than Classical Annealing.
Nevertheless, a quantum cooling protocol based on field-cycling and able to
outperform standard classical simulated annealing over short time scales is
introduced.Comment: 10 pages, 6 figures, submitted to PR
HSF2BP negatively regulates homologous recombination in DNA interstrand crosslink repair
The tumor suppressor BRCA2 is essential for homologous recombination (HR), replication fork stability and DNA interstrand crosslink (ICL) repair in vertebrates. We show that ectopic production of HSF2BP, a BRCA2-interacting protein required for meiotic HR during mouse spermatogenesis, in non-germline human cells acutely sensitize them to ICL-inducing agents (mitomycin C and cisplatin) and PARP inhibitors, resulting in a phenotype characteristic of cells from Fanconi anemia (FA) patients. We biochemically recapitulate the suppression of ICL repair and establish that excess HSF2BP compromises HR by triggering the removal of BRCA2 from the ICL site and thereby preventing the loading of RAD51. This establishes ectopic expression of a wild-type meiotic protein in the absence of any other protein-coding mutations as a new mechanism that can lead to an FA-like cellular phenotype. Naturally occurring elevated production of HSF2BP in tumors may be a source of cancer-promoting genomic instability and also a targetable vulnerability
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