2,041 research outputs found
Sunsets and solar diameter measurement
A sunset over the sea surface offers the possibility to chronometrate a solar
transit across the horizon. The vertical solar diameter is proportional to the
duration of the sunset, the cosine of the azimuth and the cosine of the
latitude of the observing site. The same formula applies to every circle of
equal height, called in arabic almucantarat, and it is exploited in the
measurements of the solar diameter made with the Danjon's solar astrolabes. The
analogies between sunsets and astrolabes observations are presented, showing
advantages and sources of errors of these methods of solar astrometry.Comment: 8 pages, 3 figures, Proc. of 2nd Galileo-Xu Guangqi Meeting,
Ventimiglia - Villa Hanbury, Italy, 11-16 July 201
Feeding and metabolism of the jellyfish Pelagia noctiluca (scyphomedusae, semaeostomae)
International audienc
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Internship Experiences Contribute to Confident Career Decision Making for Doctoral Students in the Life Sciences.
The Graduate Student Internships for Career Exploration (GSICE) program at the University of California, San Francisco (UCSF), offers structured training and hands-on experience through internships for a broad range of PhD-level careers. The GSICE program model was successfully replicated at the University of California, Davis (UC Davis). Here, we present outcome data for a total of 217 PhD students participating in the UCSF and UC Davis programs from 2010 to 2015 and 2014 to 2015, respectively. The internship programs at the two sites demonstrated comparable participation, internship completion rates, and overall outcomes. Using survey, focus group, and individual interview data, we find that the programs provide students with career development skills, while increasing students' confidence in career exploration and decision making. Internships, in particular, were perceived by students to increase their ability to discern a career area of choice and to increase confidence in pursuing that career. We present data showing that program participation does not change median time to degree and may help some trainees avoid "default postdocs." Our findings suggest important strategies for institutions developing internship programs for PhD students, namely: including a structured training component, allowing postgraduation internships, and providing a central organization point for internship programs
Connections and dynamical trajectories in generalised Newton-Cartan gravity I. An intrinsic view
The "metric" structure of nonrelativistic spacetimes consists of a one-form
(the absolute clock) whose kernel is endowed with a positive-definite metric.
Contrarily to the relativistic case, the metric structure and the torsion do
not determine a unique Galilean (i.e. compatible) connection. This subtlety is
intimately related to the fact that the timelike part of the torsion is
proportional to the exterior derivative of the absolute clock. When the latter
is not closed, torsionfreeness and metric-compatibility are thus mutually
exclusive. We will explore generalisations of Galilean connections along the
two corresponding alternative roads in a series of papers. In the present one,
we focus on compatible connections and investigate the equivalence problem
(i.e. the search for the necessary data allowing to uniquely determine
connections) in the torsionfree and torsional cases. More precisely, we
characterise the affine structure of the spaces of such connections and display
the associated model vector spaces. In contrast with the relativistic case, the
metric structure does not single out a privileged origin for the space of
metric-compatible connections. In our construction, the role of the Levi-Civita
connection is played by a whole class of privileged origins, the so-called
torsional Newton-Cartan (TNC) geometries recently investigated in the
literature. Finally, we discuss a generalisation of Newtonian connections to
the torsional case.Comment: 79 pages, 7 figures; v2: added material on affine structure of
connection space, former Section 4 postponed to 3rd paper of the serie
Small-scale distribution of macroplankton and micronekton in the Ligurian Sea (Mediterranean Sea) as observed from the manned submersible Cyana
International audienc
Systematic Assessment of the Climate Sensitivity of Important Human and Domestic Animals Pathogens in Europe
Climate change is expected to threaten human health and well-being via its effects on climate-sensitive infectious diseases, potentially changing their spatial distributions, affecting annual/seasonal cycles, or altering disease incidence and severity. Climate sensitivity of pathogens is a key indicator that diseases might respond to climate change, but the proportion of pathogens that is climate-sensitive, and their characteristics, are not known. The climate sensitivity of European human and domestic animal infectious pathogens, and the characteristics associated with sensitivity, were assessed systematically in terms of selection of pathogens and choice of literature reviewed. Sixty-three percent (N = 157) of pathogens were climate sensitive; 82% to primary drivers such as rainfall and temperature. Protozoa and helminths, vector-borne, foodborne, soilborne and waterborne transmission routes were associated with larger numbers of climate drivers. Zoonotic pathogens were more climate sensitive than human- or animal-only pathogens. Thirty-seven percent of disability-adjusted-life-years arise from human infectious diseases that are sensitive to primary climate drivers. These results help prioritize surveillance for pathogens that may respond to climate change. Although this study identifies a high degree of climate sensitivity among important pathogens, their response to climate change will be dependent on the nature of their association with climate drivers and impacts of other drivers
Ferromagnetic effect and spin assignment for the 390 keV state in 62Cu
The 390 keV isomeric state of 62Cu is assigned as Jπ = 4+. The magnetic hyperfine interaction has been observed in the 60Ni(α, pnγ) 62Cu reaction and the deduced Larmor period is consistent with known values of g and the hyperfine field of Cu in Ni
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