Navigating Diverse Perspectives: The Longitudinal Development of Children’s Intellectual Humility in Philosophical Dialogues

Developmental accounts of intellectual humility (IH) are currently emerging and thus little is known about how children engage in IH and which contexts may support its development. Further, IH has yet to be operationalized within a dialogic context in childhood. Philosophy for/with Children (P4wC) is a pedagogy that has been heavily theorized to foster epistemic virtues such as IH, and may be an informative context within which to study IH in children. The present study is a longitudinal, instrumental case study analysis of the development of IH in the context of P4wC dialogues among five children who participated in activities associated with a P4wC-based charity over four years between 2015-2018. From a situative analytic lens, this study elucidates how children’s participation in P4wC dialogues supports the development of IH. My findings suggest four categories of discursive indicators associated with IH and two broad categories of indicators associated with a lack of IH. The categories associated with IH are: self-correction, openness to others, willingness to doubt and labelling one’s own perspective. Categories associated with a lack of IH are: asserting and defense to disagreement. My findings also suggest potential developmental patterns within indicators of IH, such that meta-cognitive or explicit expressions appeared after time and experience. Furthermore, this study demonstrates how dialogue type and facilitator scaffolding impact indicators of IH. Overall, this study provides evidence to suggest that children are capable of demonstrating and developing IH, and that P4wC is a good pedagogical context to foster and study IH in childhood

Water maser detections in southern candidates to post-AGB stars and Planetary Nebulae

We intended to study the incidence and characteristics of water masers in the envelopes of stars in the post-AGB and PN evolutionary stages. We have used the 64-m antenna in Parkes (Australia) to search for water maser emission at 22 GHz, towards a sample of 74 sources with IRAS colours characteristic of post-AGB stars and PNe, at declination $< -32 \deg$. In our sample, 39% of the sources are PNe or PNe candidates, and 50% are post-AGB stars or post-AGB candidates. We have detected four new water masers, all of them in optically obscured sources: three in PNe candidates (IRAS 12405-6219, IRAS 15103-5754, and IRAS 16333-4807); and one in a post-AGB candidate (IRAS 13500-6106). The PN candidate IRAS 15103-5754 has water fountain characteristics, and it could be the first PN of this class found. We confirm the tendency suggested in Paper I that the presence of water masers in the post-AGB phase is favoured in obscured sources with massive envelopes. We propose an evolutionary scenario for water masers in the post-AGB and PNe stages, in which ``water fountain'' masers could develop during post-AGB and early PN stages. Later PNe would show lower velocity maser emission, both along jets and close to the central objects, with only the central masers remaining in more evolved PNe.Comment: 11 pages, 5 figures. Accepted by Astronomy and Astrophysic

Spectral index of the H2O-maser emitting planetary nebula IRAS 17347-3139

We present radio continuum observations of the planetary nebula (PN) IRAS 17347-3139 (one of the only two known to harbour water maser emission), made to derive its spectral index and the turnover frequency of the emission. The spectrum of the source rises in the whole frequency range sampled, from 2.4 to 24.9 GHz, although the spectral index seems to decrease at the highest frequencies (0.79+-0.04 between 4.3 and 8.9 GHz, and 0.64+-0.06 between 16.1 and 24.9 GHz). This suggests a turnover frequency around 20 GHz (which is unusual among PNe, whose radio emission usually becomes optically thin at frequencies < 10 GHz), and a relatively high emission measure (1.5 x 10^9 cm^{-6} pc). The radio continuum emission has increased by a factor of ~1.26 at 8.4 GHz in 13 years, which can be explained as expansion of the ionized region by a factor of ~1.12 in radius with a dynamical age of ~120 yr and at an expansion velocity of ~5-40 km/s. These radio continuum characteristics, together with the presence of water maser emission and a strong optical extinction suggest that IRAS 17347-3139 is one of the youngest PNe known, with a relatively massive progenitor star.Comment: Five pages, 2 figures, accepted by MNRA

The determination of integral closures and geometric applications

We express explicitly the integral closures of some ring extensions; this is done for all Bring-Jerrard extensions of any degree as well as for all general extensions of degree < 6; so far such an explicit expression is known only for degree < 4 extensions. As a geometric application we present explicitly the structure sheaf of every Bring-Jerrard covering space in terms of coefficients of the equation defining the covering; in particular, we show that a degree-3 morphism f : Y --> X is quasi-etale if and only if the first Chern class of the sheaf f_*(O_Y) is trivial (details in Theorem 5.3). We also try to get a geometric Galoisness criterion for an arbitrary degree-n finite morphism; this is successfully done when n = 3 and less satifactorily done when n = 5.Comment: Advances in Mathematics, to appear (no changes, just add this info

Automorphisms of Finite Order on Rational Surfaces

We classify minimal pairs (X, G) for smooth rational projective surface X and finite group G of automorphisms on X. We also determine the fixed locus X^G and the quotient surface Y = X/G as well as the fundamental group of the smooth part of Y. The realization of each pair is included. Mori's extremal ray theory and recent results of Alexeev and also Ambro on the existence of good anti-canonical divisors are used.Comment: with an Appendix by I. Dolgachev; to appear in Journal of Algebr

Homological Type of Geometric Transitions

The present paper gives an account and quantifies the change in topology induced by small and type II geometric transitions, by introducing the notion of the \emph{homological type} of a geometric transition. The obtained results agree with, and go further than, most results and estimates, given to date by several authors, both in mathematical and physical literature.Comment: 36 pages. Minor changes: A reference and a related comment in Remark 3.2 were added. This is the final version accepted for publication in the journal Geometriae Dedicat

The influence of taphonomy on histological and isotopic analyses of treated and untreated buried modern human bone

The chemical (e.g., preservation/embalming) treatment of skeletal remains can reduce overall DNA quality and quantity. The histological and stable isotope examination of treated and untreated human remains improves our understanding of how chemical preservatives impact bone diagenesis and will determine if chemical treatment adversely affects stable isotope ratio analysis of collagen. Fidelity in the application(s) of stable isotope interpretations requires that the isotope delta (δ) values have not been altered postmortem. Re-associated antimeres and refits of chemically treated and untreated rib and long bones from eight casualties [thin-sectioned human bone (n = 43) and collagen extraction/stable isotope analysis (n = 42)] from the World War II Battle of Tarawa were examined to compare skeletal elements from the same individual that had different taphonomic histories. Histological analyses included scoring upon the Oxford Histological Index (OHI) and Birefringence scale, recording microbial invasion, and general observations. The collected data were analyzed via simple descriptive statistics and paired samples t-tests. Treated remains scored higher on the OHI and for Birefringence, indicating that bone quality was good to excellent. The untreated samples scored lower on the OHI and Birefringence scales suggesting poorer preservation than the treated remains. Histology results were supported by the isotope sample preparation results: the collagen % yield was higher for treated bone than untreated bone. Additionally, chemical preservation had no meaningful impact on isotope δ values of treated and untreated remains from the same element or pair-matched elements. Overall, treated remains exhibited good preservation while untreated remains exhibit poorer preservation with significant microfocal destruction to the extent that little histological analyses can be applied. Stable isotope ratio analysis is viable for both treated and untreated remains indicating this testing modality likely can be used for most treated remains, regardless of origin

Toric bases for 6D F-theory models

We find all smooth toric bases that support elliptically fibered Calabi-Yau threefolds, using the intersection structure of the irreducible effective divisors on the base. These bases can be used for F-theory constructions of six-dimensional quantum supergravity theories. There are 61,539 distinct possible toric bases. The associated 6D supergravity theories have a number of tensor multiplets ranging from 0 to 193. For each base an explicit Weierstrass parameterization can be determined in terms of the toric data. The toric counting of parameters matches with the gravitational anomaly constraint on massless fields. For bases associated with theories having a large number of tensor multiplets, there is a large non-Higgsable gauge group containing multiple irreducible gauge group factors, particularly those having algebras e_8, f_4 and (g_2 + su(2)) with minimal (non-Higgsable) matter.Comment: 39 pages, 13 figures, one appendix; ancillary data file contains list of 61,539 bases; v2: minor correctio

Direct measurements of western boundary currents off Brazil between 20°S and 28°S

Current measurements from three moored arrays on the Brazilian continental slope between 20 degrees S and 28 degrees S are investigated for the existence and strength of western boundary currents from near the surface down to the North Atlantic Deep Water. The Brazil Current is found to deepen southward from 100 m to more than 670 m and to strengthen its volume transport to 16.2 x 10(6) m(3)/s. Antarctic Intermediate Water is transported in a well-developed boundary current southward at 28 degrees S and northward north of Cabo Frio (24 degrees S). This result supports earlier suggestions derived from the analysis of hydrographic data that Antarctic Intermediate Water enters the Brazil Basin from the east and bifurcates as it meets the continental break off Brazil. North Atlantic Deep Water is transported southward in a weakly developed boundary current that leads to lower estimates of volume transport than expected from earlier hydrographic data analysis

A Chandra and Spitzer census of the young star cluster in the reflection nebula NGC 7129

The reflection nebula NGC 7129 has long been known to be a site of recent star formation as evidenced, e.g., by the presence of deeply embedded protostars and HH objects. However, studies of the stellar population produced in the star formation process have remained rudimentary. At a presumed age of ~3 Myr, NGC7129 is in the critical range where disks around young stars disappear. We make use of Chandra X-ray and Spitzer and 2MASS IR imaging observations to identify the pre-main sequence stars in NGC7129. We define a sample of Young Stellar Objects based on color-color diagrams composed from IR photometry between 1.6 and 8 mu, from 2MASS and Spitzer, and based on X-ray detected sources from a Chandra observation. This sample is composed of 26 Class II and 25 Class III candidates. The sample is estimated to be complete down to ~ 0.5 solar masses. The most restricted and least biased sub-sample of pre-main sequence stars is composed of lightly absorbed (A_V < 5 mag) stars in the cluster core. This sample comprises 7 Class II and 14 Class III sources, it has a disk fraction of 33^{+24}_{-19} %, and a median X-ray luminosity of log (L_x) [erg/s] = 30.3. Despite the various uncertainties related to the sample selection, absorption, mass distribution, distance and, consequently, the computation of disk fraction and X-ray luminosities, the data yield consistent results. In particular, we confirm the age of ~3 Myr for the NGC7129 cluster. The derived disk fraction is similar to that of sigma Orionis, smaller than that of Cha I (~2 Myr), and larger than that of Upper Sco (5 Myr). The X-ray luminosity function is similar to that of NGC 2264 (2 Myr) but fainter than that of the Orion Nebula Cluster (1 Myr).Comment: accepted for publication in Astronomy & Astrophysic