1,078 research outputs found
Hanbury Brown and Twiss Interferometry with Twisted Light
The rich physics exhibited by random optical wave fields permitted Hanbury
Brown and Twiss to unveil fundamental aspects of light. Furthermore, it has
been recognized that optical vortices are ubiquitous in random light and that
the phase distribution around these optical singularities inprints a spectrum
of orbital angular momentum onto a light field. We demonstrate that random
fluctuations of light give rise to the formation of correlations in the orbital
angular momentum components and angular positions of pseudothermal light. The
presence of these correlations is manisfested through distinct interference
structures in the orbital angular momentum-mode distribution of random light.
These novel forms of interference correspond to the azimuthal analog of the
Hanbury Brown and Twiss effect. This family of effects can be of fundamental
importance in applications where entanglement is not required and where
correlations in angular position and orbital angular momentum suffice. We also
suggest that the azimuthal Hanbury Brown and Twiss effect can be useful in the
exploration of novel phenomena in other branches of physics and astrophysics.Comment: Science Advance
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Oncogenic R132 IDH1 Mutations Limit NADPH for De Novo Lipogenesis through (D)2-Hydroxyglutarate Production in Fibrosarcoma Sells.
Neomorphic mutations in NADP-dependent isocitrate dehydrogenases (IDH1 and IDH2) contribute to tumorigenesis in several cancers. Although significant research has focused on the hypermethylation phenotypes associated with (D)2-hydroxyglutarate (D2HG) accumulation, the metabolic consequences of these mutations may also provide therapeutic opportunities. Here we apply flux-based approaches to genetically engineered cell lines with an endogenous IDH1 mutation to examine the metabolic impacts of increased D2HG production and altered IDH flux as a function of IDH1 mutation or expression. D2HG synthesis in IDH1-mutant cells consumes NADPH at rates similar to de novo lipogenesis. IDH1-mutant cells exhibit increased dependence on exogenous lipid sources for in vitro growth, as removal of medium lipids slows growth more dramatically in IDH1-mutant cells compared with those expressing wild-type or enzymatically inactive alleles. NADPH regeneration may be limiting for lipogenesis and potentially redox homeostasis in IDH1-mutant cells, highlighting critical links between cellular biosynthesis and redox metabolism
MarineTools.temporal: A Python package to simulate Earth and environmental time series
The assessment of the uncertainty about the evolution of complex processes usually requires different realizations consisting of multivariate temporal signals of environmental data. However, it is common to have only
one observational set. MarineTools.temporal is an open-source Python package for the non-stationary parametric
statistical analysis of vector random processes suitable for environmental and Earth modelling. It takes a single
timeseries of observations and allows the simulation of many time series with the same probabilistic behavior.
The software generalizes the use of piecewise and compound distributions with any number of arbitrary
continuous distributions. The code contains, among others, multi-model negative log-likely functions, wrappednormal distributions, and generalized Fourier timeseries expansion. Its programming philosophy significantly
improves the computing time and makes it compatible with future extensions of scipy.stats. We apply it to the
analysis of freshwater river discharge, water currents, and the simulation of ensemble projections of sea waves,
to show its capabilities
Effectiveness of Wildlife Clubs of Kenya Activities in Promoting Awareness and Positive Attitude Towards Wildlife Conservation Education
The purpose of this study was to evaluate the effectiveness of WCK activities in promoting awareness and positive attitude towards wildlife conservation education among secondary schools students’ in Kenya. This study employed descriptive survey and correlational research designs. A sample of 591 respondents was employed for the study. The study utilized questionnaires and interview schedule for data collection. The study found that there exist significant relationship between WCK activities and promotion of awareness of wildlife conservation education at 5% significance level. The level of involvement in environmental conservation activities corresponded to WCK activities demonstrating a likelihood that the involvement of respondents in WCK activities would contribute to the level of awareness towards wildlife conservation. Also, the study found that WCK activities had insignificant influence on promoting positive attitude towards wildlife conservation. This implies that WCK activities do not contribute significantly to the prediction of positive attitude towards wildlife conservation. There is need for more education and awareness program to address ignorance and lack of knowledge by community towards wildlife conservation. It is anticipated that the findings of the current study will provide necessary information useful to the policy makers, members of WCK and other stakeholders to promote the effectiveness of WCK in wildlife conservation education in Kenya. Keywords: Awareness; Attitude; Wildlife conservation education; WCK activitie
Trajectories of Self-management and Independence in Youth with Spina Bifida: Demographic Predictors of Growth
Aim: The purpose of this study was to examine the trajectories of condition and independent living self-management in youth with spina bifida (SB). MethodsA diverse sample of adolescents and young adults (AYAs) with SB completed the Adolescent/Young Adult Self-Management and Independence Scale (AMIS-II) across four time points. Parents reported on demographic characteristics including age, sex, race/ethnicity, and family income. Growth in self-management and its subscales (condition and independent living) were estimated using linear mixed-effect models as a function of respondents\u27 demographics.ResultsThis study included 99 respondents age 18 to 27 years old. About half were female (52.5%) and White (52.5%); 15.2% were Black, and about a third were Hispanic/Latino (32.3%). Eighty-seven AYAs (87.9%) had myelomeningocele. The lesion level was 31.3% sacral, 48.5% lumbar and 18.2% thoracic. A third of the families earned less than 50K. Overall, self-management growth was dependent on age, sex, and race/ethnicity, but not income. Growth in condition self-management depended on sex; only males demonstrated increasing growth ( β̂ = 0.11, p \u3c 0.001). Black participants endorsed higher increasing total and condition self-management when compared with White ( β̂diff = 0.17 and 0.17, respectively, both p \u3c 0.05) and Hispanic/Latino ( β̂diff = 0.18 and 0.21, respectively, both p = 0.02) respondents. Conclusion: This study provides evidence of differences in growth of self-management by demographic/social determinants of health. Possible reasons for differences are discussed. Predictors of changes in self-management behaviours over time in young adults with SB can identify subgroups in need of further study
STUDY OF THE O-18+Ni-64 TWO-NEUTRON TRANSFER REACTION AT 84 MeV BY MAGNEX
A study of the two-neutron transfer reaction of the O-18 + Ni-64 system at 84 MeV incident energy to the ground and first 2(+) excited state of the residual Ni-66 nucleus is presented. The experiment was performed at the INFN-LNS (Italy) by using the large acceptance MAGNEX spectrometer. Theoretical models are used in order to disentangle the competition between long-range and short-range correlations
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