scholarly journals Measures of contextuality and non-contextuality

2019 ◽  
Vol 377 (2157) ◽  
pp. 20190149 ◽  
Author(s):  
Janne V. Kujala ◽  
Ehtibar N. Dzhafarov
Keyword(s):  
Quantum Mechanics ◽  
Random Variables ◽  
The Other ◽  
Theme Issue ◽  
First Time

We discuss three measures of the degree of contextuality in contextual systems of dichotomous random variables. These measures are developed within the framework of the Contextuality-by-Default (CbD) theory, and apply to inconsistently connected systems (those with ‘disturbance’ allowed). For one of these measures of contextuality, presented here for the first time, we construct a corresponding measure of the degree of non-contextuality in non-contextual systems. The other two CbD-based measures do not suggest ways in which degree of non-contextuality of a non-contextual system can be quantified. We find the same to be true for the contextual fraction measure developed by Abramsky, Barbosa and Mansfield. This measure of contextuality is confined to consistently connected systems, but CbD allows one to generalize it to arbitrary systems. This article is part of the theme issue ‘Contextuality and probability in quantum mechanics and beyond’.

scholarly journals On joint distributions, counterfactual values and hidden variables in understanding contextuality

2019 ◽  
Vol 377 (2157) ◽  
pp. 20190144 ◽  
Author(s):  
Ehtibar N. Dzhafarov
Keyword(s):  
Quantum Mechanics ◽  
Hidden Variables ◽  
Random Variables ◽  
Mathematical Tool ◽  
Theme Issue ◽  
Joint Distributions ◽  
Hidden Variable ◽  
The Core ◽  
Made In

This paper deals with three traditional ways of defining contextuality: (C1) in terms of (non)existence of certain joint distributions involving measurements made in several mutually exclusive contexts; (C2) in terms of relationship between factual measurements in a given context and counterfactual measurements that could be made if one used other contexts; and (C3) in terms of (non)existence of ‘hidden variables’ that determine the outcomes of all factually performed measurements. It is generally believed that the three meanings are equivalent, but the issues involved are not entirely transparent. Thus, arguments have been offered that C2 may have nothing to do with C1, and the traditional formulation of C1 itself encounters difficulties when measurement outcomes in a contextual system are treated as random variables. I show that if C1 is formulated within the framework of the Contextuality-by-Default (CbD) theory, the notion of a probabilistic coupling, the core mathematical tool of CbD, subsumes both counterfactual values and ‘hidden variables’. In the latter case, a coupling itself can be viewed as a maximally parsimonious choice of a hidden variable. This article is part of the theme issue ‘Contextuality and probability in quantum mechanics and beyond’.

scholarly journals Contextuality-by-Default Description of Bell Tests: Contextuality as the Rule and Not as an Exception

Entropy ◽  
2021 ◽  
Vol 23 (9) ◽  
pp. 1104
Author(s):  
Marian Kupczynski
Keyword(s):  
Quantum Mechanics ◽  
Quantum Computing ◽  
Random Variables ◽  
Bell Inequalities ◽  
Measuring Instruments ◽  
Freedom Of Choice ◽  
Dependent Variables ◽  
Experimental Protocols ◽  
First Time ◽  
Behavioural Sciences

Contextuality and entanglement are valuable resources for quantum computing and quantum information. Bell inequalities are used to certify entanglement; thus, it is important to understand why and how they are violated. Quantum mechanics and behavioural sciences teach us that random variables ‘measuring’ the same content (the answer to the same Yes or No question) may vary, if ‘measured’ jointly with other random variables. Alice’s and BoB′s raw data confirm Einsteinian non-signaling, but setting dependent experimental protocols are used to create samples of coupled pairs of distant ±1 outcomes and to estimate correlations. Marginal expectations, estimated using these final samples, depend on distant settings. Therefore, a system of random variables ‘measured’ in Bell tests is inconsistently connected and it should be analyzed using a Contextuality-by-Default approach, what is done for the first time in this paper. The violation of Bell inequalities and inconsistent connectedness may be explained using a contextual locally causal probabilistic model in which setting dependent variables describing measuring instruments are correctly incorporated. We prove that this model does not restrict experimenters’ freedom of choice which is a prerequisite of science. Contextuality seems to be the rule and not an exception; thus, it should be carefully tested.

scholarly journals GENERATING COMPLEX POTENTIALS WITH REAL EIGENVALUES IN SUPERSYMMETRIC QUANTUM MECHANICS

2001 ◽  
Vol 16 (16) ◽  
pp. 2859-2872 ◽  
Author(s):  
B. BAGCHI ◽  
S. MALLIK ◽  
C. QUESNE
Keyword(s):  
Quantum Mechanics ◽  
Lie Algebra ◽  
Algebraic Approach ◽  
Factorization Method ◽  
Bound State ◽  
Complex Potentials ◽  
The Other ◽  
Darboux Transformations ◽  
Weierstrass Function ◽  
First Time

In the framework of SUSYQM extended to deal with non-Hermitian Hamiltonians, we analyze three sets of complex potentials with real spectra, recently derived by a potential algebraic approach based upon the complex Lie algebra [Formula: see text] . This extends to the complex domain the well-known relationship between SUSYQM and potential algebras for Hermitian Hamiltonians, resulting from their common link with the factorization method and Darboux transformations. In the same framework, we also generate for the first time a pair of elliptic partner potentials of Weierstrass ℘ type, one of them being real and the other imaginary and PT symmetric. The latter turns out to be quasiexactly solvable with one known eigenvalue corresponding to a bound state. When the Weierstrass function degenerates to a hyperbolic one, the imaginary potential becomes PT nonsymmetric and its known eigenvalue corresponds to an unbound state.

Darwin's two competing phylogenetic trees: marsupials as ancestors or sister taxa?

2012 ◽  
Vol 39 (2) ◽  
pp. 217-233 ◽  
Author(s):  
J. David Archibald
Keyword(s):  
Fossil Record ◽  
Evolutionary Biology ◽  
Phylogenetic Trees ◽  
Charles Darwin ◽  
The Other ◽  
Charles Lyell ◽  
Single Origin ◽  
Molecular Studies ◽  
Richard Owen ◽  
First Time

Studies of the origin and diversification of major groups of plants and animals are contentious topics in current evolutionary biology. This includes the study of the timing and relationships of the two major clades of extant mammals – marsupials and placentals. Molecular studies concerned with marsupial and placental origin and diversification can be at odds with the fossil record. Such studies are, however, not a recent phenomenon. Over 150 years ago Charles Darwin weighed two alternative views on the origin of marsupials and placentals. Less than a year after the publication of On the origin of species, Darwin outlined these in a letter to Charles Lyell dated 23 September 1860. The letter concluded with two competing phylogenetic diagrams. One showed marsupials as ancestral to both living marsupials and placentals, whereas the other showed a non-marsupial, non-placental as being ancestral to both living marsupials and placentals. These two diagrams are published here for the first time. These are the only such competing phylogenetic diagrams that Darwin is known to have produced. In addition to examining the question of mammalian origins in this letter and in other manuscript notes discussed here, Darwin confronted the broader issue as to whether major groups of animals had a single origin (monophyly) or were the result of “continuous creation” as advocated for some groups by Richard Owen. Charles Lyell had held similar views to those of Owen, but it is clear from correspondence with Darwin that he was beginning to accept the idea of monophyly of major groups.

Sphagnum mosses (Sphagnaceae, Bryophyta) of mires Chefandzar and Masota in North Ossetia (Caucasus)

2018 ◽  
Vol 52 (2) ◽  
pp. 455-462 ◽  
Author(s):  
G. Ya. Doroshina ◽  
I. A. Nikolajev
Keyword(s):  
Plant Communities ◽  
The Other ◽  
North Caucasus ◽  
Sphagnum Mosses ◽  
Greater Caucasus ◽  
The North ◽  
First Time ◽  
North Ossetia

Sphagnum mires on the Greater Caucasus are rare, characterized by the presence of relict plant communities of glacial age and are in a stage of degradation. The study of Sphagnum of Chefandzar and Masota mires is carried out for the first time. Seven species of Sphagnum are recorded. Their distribution and frequency within the North Caucasus are analyzed. Sphagnum contortum, S. platyphyllum, S. russowii, S. squarrosum are recorded for the first time for the study area and for the flora of North Ossetia. The other mosses found in the study area are listed.

An Epistemological Criticism of Social Entrepreneurship: Is Social Entrepreneurship a Sound Scientific Field of Research

2018 ◽  
Author(s):  
Amir Forouharfar
Keyword(s):  
Social Entrepreneurship ◽  
Social Constructivism ◽  
Social Epistemology ◽  
American English ◽  
Meta Analysis ◽  
Research Question ◽  
Knowledge Structure ◽  
Scientific Field ◽  
The Other ◽  
First Time

The paper was shaped around the pivotal question: Is SE a sound and scientific field of research? The question has given a critical tone to the paper and has also helped to bring out some of the controversial debates in the realm of SE. The paper was organized under five main discussions to be able to provide a scientific answer to the research question: (1)<b> </b>is “social entrepreneurship” an oxymoron?, (2) the characteristics of SE knowledge, (3) sources of social entrepreneurship knowledge, (4) SE knowledge: structure and limitations and (5) contributing epistemology-making concepts for SE.<b> </b>Based on the sections,<b> </b>the study relied on the relevant philosophical schools of thought in <i>Epistemology </i>(e.g. <i>Empiricism</i>, <i>Rationalism</i>, <i>Skepticism</i>, <i>Internalism</i> vs. <i>Externalism</i>,<i> Essentialism, Social Constructivism</i>, <i>Social Epistemology, etc.</i>) to discuss these controversies around SE and proposes some solutions by reviewing SE literature. Also, to determine the governing linguistic discourse in the realm of SE, which was necessary for our discussion,<i> Corpus of Contemporary American English (COCA)</i> for the first time in SE studies was used. Further, through the study, SE buzzwords which constitute SE terminology were derived and introduced to help us narrowing down and converging the thoughts in this field and demarking the epistemological boundaries of SE. The originality of the paper on one hand lies in its pioneering discussions on SE epistemology and on the other hand in paving the way for a construction of sound epistemology for SE; therefore in many cases after preparing the philosophical ground for the discussions, it went beyond the prevalent SE literature through meta-analysis to discuss the cases which were raised. The results of the study verified previously claimed embryonic pre-paradigmatic phase in SE which was far from a sound and scientific knowledge, although the scholarly endeavors are the harbingers of such a possibility in the future which calls for further mature academic discussion and development of SE knowledge by the SE academia.

A Nabatean port on the Red Sea: note on the pottery finds from al-Qusayr (al-Wajh, Saudi Arabia)

2020 ◽  
Author(s):  
Caroline Durand
Keyword(s):  
Saudi Arabia ◽  
19Th Century ◽  
Red Sea ◽  
Point Of View ◽  
The Other ◽  
Trade Routes ◽  
Other Hand ◽  
Roman Egypt ◽  
Pottery Sherds ◽  
First Time

Al-Qusayr is located 40 km south of modern al-Wajh, roughly 7 km from the eastern Red Sea shore. This site is known since the mid-19th century, when the explorer R. Burton described it for the first time, in particular the remains of a monumental building so-called al-Qasr. In March 2016, a new survey of the site was undertaken by the al-‘Ula–al-Wajh Survey Project. This survey focused not only on al-Qasr but also on the surrounding site corresponding to the ancient settlement. A surface collection of pottery sherds revealed a striking combination of Mediterranean and Egyptian imports on one hand, and of Nabataean productions on the other hand. This material is particularly homogeneous on the chronological point of view, suggesting a rather limited occupation period for the site. Attesting contacts between Mediterranean merchants, Roman Egypt and the Nabataean kingdom, these new data allow a complete reassessment of the importance of this locality in the Red Sea trade routes during antiquity.

Status of Family Fissidentaceae in Gujarat

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
D.G. Shah ◽  
D.N. Mehta ◽  
R.V. Gujar
Keyword(s):  
Distinct Species ◽  
The State ◽  
The Other ◽  
Land Plants ◽  
Reproductive Structures ◽  
The Family ◽  
The Status ◽  
Vegetative Characters ◽  
First Time ◽  
Different Parts

Bryophytes are the second largest group of land plants and are also known as the amphibians of the plant kingdom. 67 species of bryophytes have been reported from select locations across the state of Gujrat. The status of family fissidentaceae which is a large moss family is being presented in this paper. Globally the family consists of 10 genera but only one genus, Fissidens Hedw. has been collected from Gujarat. Fissidens is characterized by a unique leaf structure and shows the presence of three distinct lamina, the dorsal, the ventral and the vaginant lamina. A total of 8 species of Fissidens have been reported from the state based on vegetative characters as no sporophyte stages were collected earlier. Species reported from the neighboring states also showed the absence of sporophytes. The identification of different species was difficult due to substantial overlap in vegetative characters. Hence a detailed study on the diversity of members of Fissidentaceae in Gujarat was carried out between November 2013 and February 2015. In present study 8 distinct species of Fissidens have been collected from different parts of the state. Three species Fissidens splachnobryoides Broth., Fissidens zollingerii Mont. and Fissidens curvato-involutus Dixon. have been identified while the other five are still to be identified. Fissidens zollingerii Mont. and Fissidens xiphoides M. Fleisch., which have been reported as distinct species are actually synonyms according to TROPICOS database. The presence of sexual reproductive structures and sporophytes for several Fissidens species are also being reported for the first time from the state.

scholarly journals First Report of blaNDM-1 Bearing IncX3 Plasmid in Clinically Isolated ST11 Klebsiella pneumoniae from Pakistan

2021 ◽  
Vol 9 (5) ◽  
pp. 951
Author(s):  
Hazrat Bilal ◽  
Gaojian Zhang ◽  
Tayyab Rehman ◽  
Jianxion Han ◽  
Sabir Khan ◽  
...  
Keyword(s):  
Sequence Type ◽  
The Other ◽  
High Rate ◽  
Antibiotics Resistance ◽  
New Delhi ◽  
Molecular Type ◽  
Plasmid Analysis ◽  
First Time ◽  
Encoding Genes ◽  
Sequence Types

The New Delhi Metallo-β-lactamase (NDM) is among the most threatening forms of carbapenemases produced by K. pneumoniae, well-known to cause severe worldwide infections. The molecular epidemiology of blaNDM-1-harboring K. pneumoniae is not well elucidated in Pakistan. Herein, we aim to determine the antibiotics-resistance profile, genes type, molecular type, and plasmid analysis of 125 clinically isolated K. pneumoniae strains from urine samples during July 2018 to January 2019 in Pakistan. A total of 34 (27.2%) K. pneumoniae isolates were carbapenemases producers, and 23 (18.4%) harbored the blaNDM-1 gene. The other carbapenemases encoding genes, i.e., blaIMP-1 (7.2%), blaVIM-1 (3.2%), and blaOXA-48 (2.4%) were also detected. The Multi Locus Sequence Typing (MLST) results revealed that all blaNDM-1-harboring isolates were ST11. The other sequence types detected were ST1, ST37, and ST105. The cluster analysis of Xbal Pulsed Field Gel Electrophoresis (PFGE) revealed variation amongst the clusters of the identical sequence type isolates. The blaNDM-1 gene in all of the isolates was located on a 45-kb IncX3 plasmid, successfully transconjugated. For the first time, blaNDM-1-bearing IncX3 plasmids were identified from Pakistan, and this might be a new primary vehicle for disseminating blaNDM-1 in Enterobacteriaceae as it has a high rate of transferability.

scholarly journals On the embedding of a group in a join of given groups

1974 ◽  
Vol 17 (4) ◽  
pp. 434-495 ◽  
Author(s):  
P. Hall
Keyword(s):  
Countable Group ◽  
The Other ◽  
Other Hand ◽  
First Time ◽  
Fundamental Paper

1. In their fundamental paper of 1949, Higman, Neumann and Neumann proved for the first time that a countable group can always be embedded in some 2-generator group: [1], Theorem IV. Two kinds of improvement of this result have recently appeared. In [4], Theorem 2, Dark has shown that the embedding can always be made subnormally. On the other hand, in [2], Theorem 2.1, Levin has shown that the two generators can be given preassigned orders m > 1 and n > 2; and in [3], Miller and Schupp prove that the 2-generator group can also be made to satisfy several additional requirements, such as being complete and Hopfian.

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