1,155 research outputs found
Pleistocene hypothesis – moving Savanna perceptual preference hypothesis beyond Savanna
We provide an extension of the Savanna perceptual preference hypothesis (“Savanna Hypothesis”), supposing that interaction with landscapes offering survival advantage for human groups during evolution might have gradually evolved to permanent landscape preferences. This additional support is based on the palaeoenvironmental analysis of the spread of modern humans into Europe in the late Pleistocene and their living environments there. Our hypothesis is that the preference for park-like landscapes after African savannas experienced a kind of “refreshment” in the Pleistocene. Thus, preferences for certain types of natural settings and scenes may have a more continuous evolutionary history than previously thought. The extended Savanna Hypothesis termed “Pleistocene Hypothesis” might stimulate further work on this important topic linking human evolution and human environmental preferences
Hydrogen Spectroscopy with a Lamb-shift Polarimeter - An Alternative Approach Towards Anti-Hydrogen Spectroscopy Experiments
A Lamb-shift polarimeter, which has been built for a fast determination of
the polarization of protons and deuterons of an atomic-beam source and which is
frequently used in the ANKE experiment at COSY-J\"ulich, is shown to be an
excellent device for atomic-spectroscopy measurements of metastable hydrogen
isotopes. It is demonstrated that magnetic and electric dipole transitions in
hydrogen can be measured as a function of the external magnetic field, giving
access to the full Breit-Rabi diagram for the and the
states. This will allow the study of hyperfine structure, factors and the
classical Lamb shift. Although the data are not yet competitive with
state-of-the-art measurements, the potential of the method is enormous,
including a possible application to anti-hydrogen spectroscopy.Comment: 6 pages, 7 figures, accepted by European Physical Journal
How to measure the parity of the in collisions
Triggered by a recent paper by Thomas, Hicks and Hosaka, we investigate which
observables can be used to determine the parity of the from the
reaction near its production threshold. In
particular, we show that the sign of the spin correlation coefficient
for small excess energies yields the negative of the parity of the .
The argument relies solely on the Pauli principle and parity conservation and
is therefore model--independent.Comment: References completed, discussion on possible influence of background
added; conclusions unchange
The impact of researchers’ perceived pressure on their publication strategies
This article investigates researchers’ publication strategies and how their perceived pressure to publish and to obtain external funding are related to these strategies. The analyses rely on data from the Zurich Survey of Academics (ZSoA), an online survey representative of academics working at higher education institutions in Germany, Austria, and Switzerland. The results suggest that academics pursue both instrumental and normative publication strategies. The main finding is that academics who perceive high pressure to publish tend to employ instrumental publication strategies rather than normative ones: they are more likely to focus on the journal's reputation and the speed of publication when selecting an outlet for peer review. Publishing results in open-access outlets or in native languages other than English is less important for those under pressure. However, the extent to which researchers’ perceived pressure affects publication strategies also depends on other factors, such as the discrepancy between the time available for research and the time actually desired for research
Measurement of Partial-Wave Contributions in pp --> pp pi^0
We report a measurement of the spin-dependent total cross section ratios
delta_sigma_T/sigma_tot and delta_sigma_L/sigma_tot of the pp --> pp pi^0
reaction between 325 MeV and 400 MeV. The experiment was carried out with a
polarized internal target in a storage ring. Non-vertical beam polarization was
obtained by the use of solenoidal spin rotators. Near threshold, the knowledge
of both spin-dependent total cross sections is sufficient to deduce the
strength of certain participating partial waves, free of any model.Comment: 6 pages, 4 figure
The Polarized H and D Atomic Beam Source for ANKE at COSY-J\"ulich
A polarized atomic beam source was developed for the polarized internal
storage-cell gas target at the magnet spectrometer ANKE of COSY-J\"ulich. The
intensities of the beams injected into the storage cell, measured with a
compression tube, are hydrogen atoms/s (two hyperfine
states) and deuterium atoms/s (three hyperfine states). For
the hydrogen beam the achieved vector polarizations are . For the deuterium beam, the obtained combinations of vector
and tensor () polarizations are (with a
constant ), and or (both with vanishing ). The paper includes a detailed
technical description of the apparatus and of the investigations performed
during the development.Comment: 18 pages, 26 figures, 4 table
Spin rotation and oscillation of high energy particles in storage ring
Phenomena of rotation and oscillations of particle spin are discussed for
particles rotating in storage ring. The fact that these effects are described
by spin-dependent part of zero-angle scattering amplitude allows to use them
for the measurement of this amplitude at different energies of colliding
particles. It is shown that effect magnitudes are large and they can be
observed at the existing accelerators.Comment: Late
Who Drives Climate-relevant Policies in Brazil?
In this report, the central question of our research is who drives/obstructs climate-relevant policies in Brazil, paying special attention to renewable energy policies, climate policies and politics. We aim to identify the actors (in government, the private sector and civil society) who drive, or obstruct, efforts to reduce the carbon intensity of Brazil’s energy mix. The hypothesis here is that the actors who drive climate policies in Brazil are not specifically concerned with global climate change itself, but with economic, social or even political issues, such as energy security, job creation, competitiveness, promoting national industries, and gaining political power domestically or internationally. In that sense, climate change mitigation can be regarded as a co-benefit of other policies (energy policies included) that may have very different objectives. To answer the above-mentioned question, this research assesses renewable energy policies in Brazil, identifying key actors from government, business and civil society and their explicit, or implicit, motivations.UK Department for International Developmen
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