Search results for "sun"
showing 10 items of 935 documents
Search for Randall-Sundrum gravitons in dilepton and diphoton final states
2005
We report the first direct search for the Kaluza-Klein (KK) modes of Randall-Sundrum gravitons using dielectron, dimuon, and diphoton events observed with the D0 detector operating at the Fermilab Tevatron ppbar Collider at sqrt(s) = 1.96 TeV. No evidence for resonant production of gravitons has been found in the data corresponding to an integrated luminosity of approximately 260 pb^-1. Lower limits on the mass of the first KK mode at the 95% C.L. have been set between 250 and 785 GeV, depending on its coupling to SM particles.
Age-dependent responses to alarm calls depend on foraging activity in Willow TitsPoecile montanus
2011
Survivorship in animals depends on both foraging activities and avoidance of predation, and thus behavioural decisions often reflect a trade-off between predation risk and foraging efficiency. In this experimental study, we compared behavioural responses of free-living adult and juvenile Willow Tits Poecile montanus to a conspecific alarm call in two treatments. The alarm call was played back when a focal bird was either not feeding, or feeding on a sunflower seed on the middle part of a spruce branch. When feeding at the time of the alarm call, juveniles more often stayed motionless or moved shorter distances than adults. Our results suggest that in hierarchical groups, juveniles are force…
Estimation of Passenger Car Equivalents for single-lane roundabouts using a microsimulation-based procedure
2017
Calibration of microscopic traffic simulation models for single-lane roundabouts.Use of a meta-analytical estimation of critical and follow up headways.Use of a genetic algorithm-based procedure.Calculation of passenger car equivalents for single-lane roundabouts. Passenger car equivalents for heavy vehicles are required to carry out capacity calculations and perform operational analysis of any road entity (roadway segments or intersections). At single-lane roundabouts, the constraints to the vehicular trajectories imposed by the curvilinear geometric design and the driver's gap acceptance behaviour are expected to produce an impact of the heavy vehicles on the quality of traffic flow diffe…
Gastrointestinal stromal tumors (GISTs): Focus on histopathological diagnosis and biomolecular features
2007
Gastrointestinal stromal tumors (GISTs) are mesenchymal tumors of the gastrointestinal tract that are believed to originate from a neoplastic transformation of the intestinal pacemaker cells (interstitial cells of Cajal) normally found in the bowel wall or their precursors. Although the microscopic features have been known for a long time, the defining characteristic of GIST is the presence of the cell-surface antigen CD117 (KIT), which is demonstrated by immunohistochemistry. KIT, which is a growth factor transmembrane receptor, is the product of the proto-oncogene c-kit (chromosome 4). Surgical removal remains the only curative treatment for patients with GISTs. Tumor size, mitotic index,…
Strategies to improve vitamin D status in northern European children: exploring the merits of vitamin D fortification and supplementation.
2006
Adequacy of vitamin D in children in Europe has been the focus of a number of investigations. The results of measuring serum levels of 25-hydroxyvitamin D show high prevalence of vitamin D deficiency during the winter with lower prevalence during the summer. National policies on food fortification or individual supplementation with vitamin D have been recently revisited by the individual countries and the European Union as a whole. Optiford is a project managed by a coalition of scientists formed to optimize vitamin D fortification in the northern European Countries, was given the task to decide if food fortification with vitamin D is feasible and to provide a scientific basis for setting t…
SUNCT/SUNA in Pediatric Age: A Review of Pathophysiology and Therapeutic Options
2021
The International Classification of Headache Disorders, 3rd edition (ICHD3) defines Short-lasting Unilateral Neuralgiform Headache Attacks (SUNHA) as attacks of moderate or severe, strictly unilateral head pain lasting from seconds to minutes, occurring at least once a day and usually associated with prominent lacrimation and redness of the ipsilateral eye. Two subtypes of SUNHA are identified: Short-lasting Unilateral Neuralgiform headache attacks with Conjunctival injection and Tearing (SUNCT) and Short-lasting Unilateral Neuralgiform headache attacks with cranial Autonomic symptoms (SUNA). These pathologies are infrequent in children and difficult to diagnose. The authors reviewed the ex…
Quantifying sunk costs and learning effects in R&D persistence
2020
Abstract This paper analyzes and quantifies the fundamental factors that are likely to cause persistence in performing R&D activities: the existence of sunk costs associated with R&D activities and the process of learning that characterizes this type of activity. We estimate our model with Spanish manufacturing firms for the period 1991-2014. By decomposing the effects of sunk costs and learning effects, we find that both are important determinants of R&D persistence, and that failing to allow for learning systematically overestimates sunk cost effects. Both large firms and SMEs benefit from direct and indirect (via productivity) effects of R&D experience, but in large firms this is more li…
Wahrnehmung polarisierten Lichtes durchEupagurus
1950
(1)Eupagurus bernhardus has in its compound eye an apparatus that can distinguish polarized light like an analysator. (2) This extinction does not apply to all the polarized light, but only a certain amount of it, this may be concluded from the fact that in the former experiments the strength of vision in no case became zero. (3) Probably the analysator in the eye ofEupagurus functions as an extinguisher of the disturbing polarized light, for the sunlight reflected from the surface of water is polarized to an ample extent.
Light bosons in the photosphere and the solar abundance problem
2013
Spectroscopy is used to measure the elemental abundances in the outer layers of the Sun, whereas helioseismology probes the interior. It is well known that current spectroscopic determinations of the chemical composition are starkly at odds with the metallicity implied by helioseismology. We investigate whether the discrepancy may be due to conversion of photons to a new light boson in the solar photosphere. We examine the impact of particles with axion-like interactions with the photon on the inferred photospheric abundances, showing that resonant axion-photon conversion is not possible in the region of the solar atmosphere in which line formation occurs. Although non-resonant conversion i…
Transverse Oscillations in Slender Ca II H Fibrils Observed with Sunrise/SuFI
2016
S. Jafarzadeh et. al.