Parents and children during the COVID-19 quarantine process: Experiences from Turkey and China

This paper reports Turkish and Chinese parents’ experiences with their 3-6-year-old children during the COVID-19 quarantine process. Thirteen Turkish and 11 Chinese parents participated in a study that employed semi-structured interviews to examine participant self-perceived experiences. Findings show that the study revealed many commonalities in the experiences of Turkish and Chinese parents with their children during the COVID-19 quarantine process. Cultural differences between parents did not appear to significantly reflect the responses of parents during this extraordinary period. Parents mostly described difficulties with home quarantine. Most parents stated that their daily schedule and routines had changed as a result of home quarantine. Parents also said that they were unaware of their children’s developmental progress and the extent to which their children had grown up before the quarantine. Parents shared both positive and negative experiences during the process. Since the quarantine process is an extraordinary experience for all family members, parents should be encouraged to put those positive experiences and acquisitions into their future life

Creative Potential in Science: Conceptual and Measurement Issues

This paper examines the concept of creative potential as it applies in science. First, conceptual issues concerning the definition of creative potential are explored, highlighting that creative potential is a moving target, and measures of creative potential are estimates of future behavior. Then three main ways to detect creative potential are examined. First, a person's previous accomplishments in science can be analyzed. These accomplishments can be regarded as predictors of future creative performance. Second, science talent competitions can help to detect creative potential in children and adolescents. There are particular types of talent competitions differing from each other by the extent of focusing on individual (e.g., Science Fairs) or collaborative (e.g., Science Olympiads) work. Third, to measure an individual's creative potential, psychometric tools such as Creative Scientific Ability Test (C-SAT), Test of Scientific Creativity Animations for Children (TOSCAC), and Evaluation of Potential Creativity (EPoC) can be used. These tools are conceptualized in terms of two scientific activities: hypothesis generation and hypothesis testing. In a final section, these three types of measures are placed in a novel time-space framework as applied to creative potential. Suggestions for future work are also discussed

Statistics of Lyapunov exponent in one-dimensional layered systems

Localization of acoustic waves in a one dimensional water duct containing many randomly distributed air filled blocks is studied. Both the Lyapunov exponent and its variance are computed. Their statistical properties are also explored extensively. The results reveal that in this system the single parameter scaling is generally inadequate no matter whether the frequency we consider is located in a pass band or in a band gap. This contradicts the earlier observations in an optical case. We compare the results with two optical cases and give a possible explanation of the origin of the different behaviors.Comment: 6 pages revtex file, 6 eps figure

Papillary microcarcinomas of the thyroid gland and immunohistochemical analysis of expression of p53 protein in papillary microcarcinomas

BACKGROUND: Thyroid papillary microcarcinoma (TPM) is defined according to WHO criteria as a thyroid tumor smaller than 1–1.5 cm. TPMs are encountered in 0.5–35.6 % of autopsies or surgical specimens where carcinoma had been unsuspected. The purpose of the present study was to evaluate patients who had TPMs in terms of clinical findings, histopathological features and immunohistochemical evidence of expression of the tumor suppressor gene p53. METHODS: A total of 44 patients with TPMs less than 1.0 cm in diameter were included in the study. The patients were evaluated clinically and the tumors were evaluated in terms of their histopathological and immunohistochemical features, including expression of p53. RESULTS: The female/male ratio was 2.8/1, and the median age at time of diagnosis was 49 years (range 20–71 years). The maximum diameter of the smallest focus was 0.1 mm, and that of the largest was 10 mm microscopically. The mean diameter of all tumors was 5.7 mm. There was no correlation between tumor size and age or gender. Of the TPMs, 72 % were found in the right lobe, 24 % in the left lobe and 4 % in the isthmus. Fine-needle aspiration biopsy provided the diagnosis of TPM in only 43.2 % of the patients. All patients were treated with surgery, with 20 undergoing conservative surgery, i.e. lobectomy or isthmusectomy, and 24 undergoing total thyroidectomy. Frozen section provided the diagnosis of TPM in only 56.8 % of the patients. We found lymphocytic thyroiditis in 13.6% of patients, follicular variants in 11.9%, capsular invasion in 26.8%, lymph node involvement in 11.9%, soft tissue metastases in the neck in 12.1% and multifocality in 31.7 %, and none of these were related to age or gender (p > 0.05). No distant metastases were observed during approximately 10 years of follow up. We found p53 positivity in 34.5 % of TPM tumors. However, p53 expression was not statistically related to age or gender. CONCLUSION: Our findings imply that TPMs may not be entirely innocent since they are associated with signs of poor prognosis such as capsular invasion, multifocal presentation, lymph node involvement and p53 positivity. Therefore, TPMs should be evaluated and followed like classical papillary cancers

Theory of optical spectra of polar quantum wells: Temperature effects

Theoretical and numerical calculations of the optical absorption spectra of excitons interacting with longitudinal-optical phonons in quasi-2D polar semiconductors are presented. In II-VI semiconductor quantum wells, exciton binding energy can be tuned on- and off-resonance with the longitudinal-optical phonon energy by varying the quantum well width. A comprehensive picture of this tunning effect on the temperature-dependent exciton absorption spectrum is derived, using the exciton Green's function formalism at finite temperature. The effective exciton-phonon interaction is included in the Bethe-Salpeter equation. Numerical results are illustrated for ZnSe-based quantum wells. At low temperatures, both a single exciton peak as well as a continuum resonance state are found in the optical absorption spectra. By contrast, at high enough temperatures, a splitting of the exciton line due to the real phonon absorption processes is predicted. Possible previous experimental observations of this splitting are discussed.Comment: 10 pages, 9 figures, to appear in Phys. Rev. B. Permanent address: [email protected]

Propagation of a hole on a Neel background

We analyze the motion of a single hole on a N\'eel background, neglecting spin fluctuations. Brinkman and Rice studied this problem on a cubic lattice, introducing the retraceable-path approximation for the hole Green's function, exact in a one-dimensional lattice. Metzner et al. showed that the approximationalso becomes exact in the infinite-dimensional limit. We introduce a new approach to this problem by resumming the Nagaoka expansion of the propagator in terms of non-retraceable skeleton-paths dressed by retraceable-path insertions. This resummation opens the way to an almost quantitative solution of the problemin all dimensions and, in particular sheds new light on the question of the position of the band-edges. We studied the motion of the hole on a double chain and a square lattice, for which deviations from the retraceable-path approximation are expected to be most pronounced. The density of states is mostly adequately accounted for by the retra\-ce\-able-path approximation. Our band-edge determination points towards an absence of band tails extending to the Nagaoka energy in the spectrums of the double chain and the square lattice. We also evaluated the spectral density and the self-energy, exhibiting k-dependence due to finite dimensionality. We find good agreement with recent numerical results obtained by Sorella et al. with the Lanczos spectra decoding method. The method we employ enables us to identify the hole paths which are responsible for the various features present in the density of states and the spectral density.Comment: 26 pages,Revte

Mars Sample Return: The Value of Depth Profiles

Sample return from Mars offers the promise of data from Martian materials that have previously only been available from meteorites. Return of carefully selected samples may yield more information about the history of water and possible habitability through Martian history. Here we propose that samples collected from Mars should include depth profiles of material across the interface between weathered material on the surface of Mars into unweathered parent rock material. Such profiles have the potential to yield chemical kinetic data that can be used to estimate the duration of water and information about potential habitats on Mars

Universality classes of three-dimensional mnmn-vector model

We study the conditions under which the critical behavior of the three-dimensional $mn$-vector model does not belong to the spherically symmetrical universality class. In the calculations we rely on the field-theoretical renormalization group approach in different regularization schemes adjusted by resummation and extended analysis of the series for renormalization-group functions which are known for the model in high orders of perturbation theory. The phase diagram of the three-dimensional $mn$-vector model is built marking out domains in the $mn$-plane where the model belongs to a given universality class.Comment: 9 pages, 1 figur

Critical behavior of three-dimensional magnets with complicated ordering from three-loop renormalization-group expansions

The critical behavior of a model describing phase transitions in 3D antiferromagnets with 2N-component real order parameters is studied within the renormalization-group (RG) approach. The RG functions are calculated in the three-loop order and resummed by the generalized Pade-Borel procedure preserving the specific symmetry properties of the model. An anisotropic stable fixed point is found to exist in the RG flow diagram for N > 1 and lies near the Bose fixed point; corresponding critical exponents are close to those of the XY model. The accuracy of the results obtained is discussed and estimated.Comment: 10 pages, LaTeX, revised version published in Phys. Rev.

On critical behavior of phase transitions in certain antiferromagnets with complicated ordering

Within the four-loop \ve expansion, we study the critical behavior of certain antiferromagnets with complicated ordering. We show that an anisotropic stable fixed point governs the phase transitions with new critical exponents. This is supported by the estimate of critical dimensionality $N_c^C=1.445(20)$ obtained from six loops via the exact relation $N_c^C={1/2} N_c^R$ established for the real and complex hypercubic models.Comment: Published versio