3,612 research outputs found
Non-radial oscillations in M-giant semi-regular variables: Stellar models and Kepler observations
The success of asteroseismology relies heavily on our ability to identify the
frequency patterns of stellar oscillation modes. For stars like the Sun this is
relatively easy because the mode frequencies follow a regular pattern described
by a well-founded asymptotic relation. When a solar like star evolves off the
main sequence and onto the red giant branch its structure changes dramatically
resulting in changes in the frequency pattern of the modes. We follow the
evolution of the adiabatic frequency pattern from the main sequence to near the
tip of the red giant branch for a series of models. We find a significant
departure from the asymptotic relation for the non-radial modes near the red
giant branch tip, resulting in a triplet frequency pattern. To support our
investigation we analyze almost four years of Kepler data of the most luminous
stars in the field (late K and early M type) and find that their frequency
spectra indeed show a triplet pattern dominated by dipole modes even for the
most luminous stars in our sample. Our identification explains previous results
from ground-based observations reporting fine structure in the Petersen diagram
and sub ridges in the period-luminosity diagram. Finally, we find `new ridges'
of non-radial modes with frequencies below the fundamental mode in our model
calculations, and we speculate they are related to f modes.Comment: 8 page, 5 figures, accepted by ApJL (ApJ, 788, L10
Sir Arthur Keith's Legacy: Re-discovering a lost collection of human fossils Quaternary International
In 2001, a collection of skeletal material was donated to the Natural History Museum, London, by the Royal College of Surgeons, London. It consisted of boxes discovered among the personal belongings of Sir Arthur Keith. This paper describes the work undertaken to identify and document the human skeletal material in the Keith Collection. The study identified the human fossils as having come from a number of excavations directed by Dorothy Garrod in the 1920s and 30s in Israel. The collection contains the long considered lost human skeletal collection from the type-site of the Natufian industry: Shukbah Cave. The majority of this material is of Natufian origin but contains a few Neanderthal specimens. A small amount of heavily fragmented bones associated with Skhul VII and IX were also found. The most remarkable of the re-discovered collection is the material from el-Wad and Kebara Caves. It was identified to be the missing material from the Middle and Upper Paleolithic levels briefly described in 1939 in The Stone Age of Mount Carmel by Theodore McCown and Sir Arthur Keith. These important fossils hold great potential to answer questions about the Middle to Upper Paleolithic transition in the Near East, and the emergence of anatomically modern humans
Non-pollinator fig wasp impact on the reproductive success of an invasive fig tree: why so little?
Classical biological control agents fail to achieve an impact on their hosts for a variety of reasons and an understanding of why they fail can help shape decisions on subsequent releases. Ornamental Ficus microcarpa is a widely planted avenue fig tree that is invasive in countries where its pollinator (Eupristina verticillata) is also introduced. This tree also supports more than 20 species of non-pollinating fig wasps (NPFW) that feed in the figs and have the potential to reduce the plant’s reproduction. Odontofroggatia galili, one of the most widely introduced NPFW, has larvae that develop in galled ovules that might otherwise develop into seeds or support pollinator larvae. We examined the distribution and relative abundance of the pollinator and O. galili on F. microcarpa in China, towards the northern limit of the tree’s natural range, and in Italy where the two species have been introduced. Where they co-existed, we also recorded the impact of varying densities of O. galili on F. microcarpa seed and pollinator production. O. galili and E. verticillata displayed contrasting habitat preferences in China, with O. galili almost absent from warmer sites. O. galili abundance and sex ratios varied between the natural and introduced ranges. Figs with more O. galili contained fewer seeds and pollinator offspring, but reproduction was rarely inhibited totally. Additional species with a greater impact in the figs they occupy are needed if biocontrol of F. microcarpa is to be effective
Literacy practices of primary education children in Andalusia (Spain): a family-based perspective
Primary school children develop literacy practices in various domains and situations in everyday life.
This study focused on the analysis of literacy practices of children aged 8–12 years from the perspec-
tive of their families. 1,843 families participated in the non-experimental explanatory study. The
children in these families speak Spanish as a first language and are schooled in this language. The
instrument used was a self-report questionnaire about children’s home-literacy practices. The data
obtained were analysed using categorical principal components analysis (CATPCA) and analysis of
variance (ANOVA). The results show the complex relationship between literacy practices developed
by children in the domains of home and school and the limited development of a literacy-promoting
‘third space’. In conclusion, the families in our study had limited awareness of their role as literacy-
promoting agents and thought of literacy learning as restricted to formal or academic spaces
Latent Factor Modeling of Four Schizotypy Dimensions with Theory of Mind and Empathy
Preliminary evidence suggests that theory of mind and empathy relate differentially to factors of schizotypy. The current study assessed 686 undergraduate students and used structural equation modeling to examine links between a four-factor model of schizotypy with performance on measures of theory of mind (Reading the Mind in the Eyes Test [MIE]) and empathy (Interpersonal Reactivity Index [IRI]). Schizotypy was assessed using three self-report measures which were simultaneously entered into the model. Results revealed that the Negative factor of schizotypy showed a negative relationship with the Empathy factor, which was primarily driven by the Empathic Concern subscale of the IRI and the No Close Friends and Constricted Affect subscales of the Schizotypal Personality Questionnaire. These findings are consistent with a growing body of literature suggesting a relatively specific relationship between negative schizotypy and empathy, and are consistent with several previous studies that found no relationship between MIE performance and schizotypy
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