On a New Approach for Constructing Wormholes in Einstein-Born-Infeld Gravity

We study a new approach for the wormhole construction in Einstein-Born-Infeld gravity, which does not require exotic matters in the Einstein equation. The Born-Infeld field equation is not modified from "coordinate independent" conditions of continuous metric tensor and its derivatives, even though the Born-Infeld fields have discontinuities in their derivatives at the throat in general. We study the relation of the newly introduced conditions with the usual continuity equation for the energy-momentum tensor and the gravitational Bianchi identity. We find that there is no violation of energy conditions for the Born-Infeld fields contrary to the usual approaches. The exoticity of energy-momentum tensor is not essential for sustaining wormholes. Some open problems are discussed.Comment: Minor revision to improve the clarity, Corrected typos, Added reference and footnot

Quasi-Normal Modes of a Natural AdS Wormhole in Einstein-Born-Infeld Gravity

We study the matter perturbations of a new AdS wormhole in (3+1)-dimensional Einstein-Born-Infeld gravity, called "natural wormhole", which does not require exotic matters. We discuss the stability of the perturbations by numerically computing the quasi-normal modes (QNMs) of a massive scalar field in the wormhole background. We investigate the dependence of quasi-normal frequencies on the mass of scalar field as well as other parameters of the wormhole. It is found that the perturbations are always stable for the wormhole geometry which has the general relativity (GR) limit when the scalar field mass m satisfies a certain, tachyonic mass bound m^2 > m^2_* with m^2_* < 0, analogous to the Breitenlohner-Freedman (BF) bound in the global-AdS space, m^2_BF = 3 Lambda/4. It is also found that the BF-like bound m^2_* shifts by the changes of the cosmological constant Lambda or angular-momentum number l, with a level crossing between the lowest complex and pure-imaginary modes for zero angular momentum l = 0. Furthermore, it is found that the unstable modes can also have oscillatory parts as well as non-oscillatory parts depending on whether the real and imaginary parts of frequencies are dependent on each other or not, contrary to arguments in the literature. For wormhole geometries which do not have the GR limit, the BF-like bound does not occur and the perturbations are stable for arbitrary tachyonic and non-tachyonic masses, up to a critical mass m^2_c > 0 where the perturbations are completely frozen.Comment: Added comments and references, Accepted in EPJ

Dataset for the proteomic and transcriptomic analyses of perivitelline fluid proteins in Pomacea snail eggs

This article describes how the proteomic and transcriptomic data were produced during a study of the reproductive proteins of Pomacea maculata, an aquatic apple snail laying colorful aerial eggs, and provides public access to the data. The data are related to a research article titled ?An integrated proteomic and transcriptomic analysis of perivitelline fluid proteins in a freshwater gastropod laying aerial eggs? (Mu et al., 2017) [1]. RNA was extracted from the albumen gland and other tissues and sequenced on an Illumina Hiseq. 2000. The assembled transcriptome was translated into protein sequences and then used for protein identification. Proteins from the perivitelline fluid of P. maculata were separated in SDS-PAGE and analyzed by LTQ-Orbitrap Elite coupled to an Easy-nLC. The translated transcriptome data are provided in this article. Proteomic data (.raw file format) are available via ProteomeXchange with the identifier PXD006718.Fil: Mu, Huawei. Hong Kong Baptist University; ChinaFil: Sun, Jin. Hong Kong University; ChinaFil: Heras, Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Bioquímicas de La Plata "Prof. Dr. Rodolfo R. Brenner". Universidad Nacional de la Plata. Facultad de Ciencias Médicas. Instituto de Investigaciones Bioquímicas de La Plata ; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Chu, Ka Hou. Chinese University of Hong Kong; ChinaFil: Qiu, Jian Wen. Hong Kong Baptist University; Chin

A Measurement-Driven Process Model For Managing Inconsistent Software Requirements

Inconsistency is a pervasive issue in software engineering. Both general rules of inconsistency management and special case-based approaches to handling inconsistency have recently been considered. In this paper, we present a process model for handling requirements inconsistency within the Viewpoints framework. In this process model, when an inconsistency among viewpoints is detected, a set of candidate proposals for handling inconsistency will be generated using techniques fromMulti-agent automated negotiations. The proposals are then prioritized using an integrated measurement of inconsistencies. The viewpoints involved in the inconsistency will then enter the negotiations by being presented with the candidate proposals and thus selecting an acceptable proposal based on the priorities associated with each candidate proposal. To facilitate usability, in our process, we assume that the natural language requirements statements are first translated into corresponding logical formulas using a translator software. Moreover, the candidate proposals for handling inconsistency are also translated back from formal logic into natural language before being presented for selection

A readily accessible multifunctional probe: simultaneous recognition of the cation ZN²⁺ and the anion F⁻ via distinguishable wavelengths

The probe 1 was readily prepared via condensation of 8-formyl-7-hydroxy-coumarin and carbonic dihydrazide in a one-step procedure. Probe 1 exhibited high sensitivity and selectivity towards Zn²⁺ and F⁻ through a “turn-on” fluorescence response and/or ratiometric colorimetric response with low detection limits of the order of 10-8 M. The complex behaviour was fully investigated by spectral titration, isothermal titration calorimetry, 1H NMR spectroscopic titration and mass spectrometry. Interestingly, probe 1 not only recognizes the cation Zn²⁺ and the anion F⁻, but can also distinguish between these two ions via the max wavelength in their UV-vis spectra (360 nm for 1-Zn²⁺ versus 400 nm for 1-F⁻ complex) or their fluorescent spectra (λₑₓ / λₑm = 360 nm/ 454 nm for 1-Zn²⁺ versus λₑₓ / λₑm = 400 nm/ 475 nm for 1-F⁻ complex) due to their differing red-shifts. Additionally, probe 1 has been further explored in the detection of Zn²⁺ in living cells

Conceptualizing and measuring instructional quality in mathematics education: A systematic literature review

Conceptualizing and measuring instructional quality is important to understand what can be understood as “good teaching” and develop approaches to improve instruction. There is a consensus in teaching effectiveness research that instructional quality should be considered multidimensional with at least three basic dimensions rather than a unitary construct: student support, cognitive activation, and classroom management. Many studies have used this or similar frameworks as a foundation for empirical research. The purpose of this paper is to investigate the relation between the conceptual indicators underlying the conceptual definitions of the quality dimensions in the literature, and the various operational indicators used to operationalize these factors in empirical studies. We examined (a) which conceptual indicators are used to conceptualize the basic dimensions theoretically, (b) to which extent the operational indicator in the literature cover these conceptual indicators, and (c) if which additional indicators are addressed by the measurement instruments, which are not part of the theoretical conceptualization. We conducted a systematic literature review on the conceptualization and operationalization of Instructional Quality in Primary and Secondary Mathematics Education based on PRISMA procedures. We describe the span of conceptual indicators connected to the three basic dimensions over all articles (a) and analyze to which extent the measurement instruments are in line with these conceptual indicators (b, c). For each measurement dimension, the identified quality dimensions identified are, taken together, largely representative of the conceptual indicators connected to the core factor, but also a number of critical misconceptions occurred. Our review provides a comprehensive overview of the three basic dimensions of instructional quality in mathematics based on theoretical conceptualizations and measurement instruments in the literature. Beyond this, we observed that the descriptions of a substantial amount of quality dimensions and their conceptualizations did not clearly specify if the intended measurement referred to the learning opportunities orchestrated by the teacher, or the utilization of these opportunities by students. It remains a challenge to differentiate measures of instructional quality (as orchestrated by the teacher) from (perceived) teacher competencies/knowledge, and students’ reactions to the instruction. Recommendations are made for measurement practice, as well as directions for future research