scholarly journals Quantum potentiality revisited

2017 ◽  
Vol 375 (2106) ◽  
pp. 20160390 ◽  
Author(s):  
Gregg Jaeger
Keyword(s):  
Quantum System ◽  
Careful Consideration ◽  
Full Detail ◽  
Natural Evolution ◽  
Quantum Revolution ◽  
The Relationship ◽  
Physical Causation ◽  
Common Character

Heisenberg offered an interpretation of the quantum state which made use of a quantitative version of an earlier notion, , of Aristotle by both referring to it using its Latin name, potentia , and identifying its qualitative aspect with . The relationship between this use and Aristotle's notion was not made by Heisenberg in full detail, beyond noting their common character: that of signifying the system's objective capacity to be found later to possess a property in actuality. For such actualization, Heisenberg required measurement to have taken place, an interaction with external systems that disrupts the otherwise independent, natural evolution of the quantum system. The notion of state actualization was later taken up by others, including Shimony, in the search for a law-like measurement process. Yet, the relation of quantum potentiality to Aristotle's original notion has been viewed as mainly terminological, even by those who used it thus. Here, I reconsider the relation of Heisenberg's notion to Aristotle's and show that it can be explicated in greater specificity than Heisenberg did. This is accomplished through the careful consideration of the role of potentia in physical causation and explanation, and done in order to provide a fuller understanding of this aspect of Heisenberg's approach to quantum mechanics. Most importantly, it is pointed out that Heisenberg's requirement of an external intervention during measurement that disrupts the otherwise independent, natural evolution of the quantum system is in accord with Aristotle's characterization of spontaneous causation. Thus, the need for a teleological understanding of the actualization of potentia, an often assumed requirement that has left this fundamental notion neglected, is seen to be spurious. This article is part of the themed issue ‘Second quantum revolution: foundational questions’.

scholarly journals Richness of Rhizosphere Organisms Affects Plant P Nutrition According to P Source and Mobility

Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 157
Author(s):  
Jean Trap ◽  
Patricia Mahafaka Ranoarisoa ◽  
Usman Irshad ◽  
Claude Plassard
Keyword(s):  
Careful Consideration ◽  
Soil Conditions ◽  
Organic P ◽  
P Nutrition ◽  
Soil P ◽  
P Acquisition ◽  
Complex Interactions ◽  
Experimental Trials ◽  
The Relationship

Plants evolve complex interactions with diverse soil mutualist organisms to enhance P mobilization from the soil. These strategies are particularly important when P is poorly available. It is still unclear how the soil P source (e.g., mineral P versus recalcitrant organic P) and its mobility in the soil (high or low) affect soil mutualist biological (ectomycorrhizal fungi, bacteria and bacterial-feeding nematodes) richness—plant P acquisition relationships. Using a set of six microcosm experiments conducted in growth chamber across contrasting P situations, we tested the hypothesis that the relationship between the increasing addition of soil mutualist organisms in the rhizosphere of the plant and plant P acquisition depends on P source and mobility. The highest correlation (R2 = 0.70) between plant P acquisition with soil rhizosphere biological richness was found in a high P-sorbing soil amended with an organic P source. In the five other situations, the relationships became significant either in soil conditions, with or without mineral P addition, or when the P source was supplied as organic P in the absence of soil, although with a low correlation coefficient (0.09 < R2 < 0.15). We thus encourage the systematic and careful consideration of the form and mobility of P in the experimental trials that aim to assess the role of biological complexity on plant P nutrition.

scholarly journals Are Virtual Particles Less Real?

Entropy ◽  
2019 ◽  
Vol 21 (2) ◽  
pp. 141 ◽  
Author(s):  
Gregg Jaeger
Keyword(s):  
Quantum Field ◽  
Interacting Particles ◽  
Virtual Particles ◽  
Quantum Particles ◽  
Action At A Distance ◽  
Relationship Of ◽  
The Relationship

The question of whether virtual quantum particles exist is considered here in light of previous critical analysis and under the assumption that there are particles in the world as described by quantum field theory. The relationship of the classification of particles to quantum-field-theoretic calculations and the diagrammatic aids that are often used in them is clarified. It is pointed out that the distinction between virtual particles and others and, therefore, judgments regarding their reality have been made on basis of these methods rather than on their physical characteristics. As such, it has obscured the question of their existence. It is here argued that the most influential arguments against the existence of virtual particles but not other particles fail because they either are arguments against the existence of particles in general rather than virtual particles per se, or are dependent on the imposition of classical intuitions on quantum systems, or are simply beside the point. Several reasons are then provided for considering virtual particles real, such as their descriptive, explanatory, and predictive value, and a clearer characterization of virtuality—one in terms of intermediate states—that also applies beyond perturbation theory is provided. It is also pointed out that in the role of force mediators, they serve to preclude action-at-a-distance between interacting particles. For these reasons, it is concluded that virtual particles are as real as other quantum particles.

scholarly journals Traumatic glioblastoma: commentary and suggested mechanism

2018 ◽  
Vol 46 (6) ◽  
pp. 2170-2176
Author(s):  
Nissim Ohana ◽  
Daniel Benharroch ◽  
Dimitri Sheinis ◽  
Abraham Cohen
Keyword(s):  
Traumatic Brain Injury ◽  
Transcription Factors ◽  
Brain Injury ◽  
Brain Injuries ◽  
Hypoxia Inducible Factor ◽  
Subsequent Development ◽  
Factors Associated ◽  
The Relationship

The role of head trauma in the development of glioblastoma is highly controversial and has been minimized since first put forward. This is not unexpected because skull injuries are overwhelmingly more common than glioblastoma. This paper presents a commentary based on the contributions of James Ewing, who established a major set of criteria for the recognition of an official relationship between trauma and cancer. Ewing’s criteria were very stringent. The scholars who succeeded Ewing have facilitated the characterization of traumatic brain injuries since the introduction of computed tomography and magnetic resonance imaging. Discussions of the various criteria that have since developed are now being conducted, and those of an unnecessarily limiting nature are being highlighted. Three transcription factors associated with traumatic brain injury have been identified: p53, hypoxia-inducible factor-1α, and c-MYC. A role for these three transcription factors in the relationship between traumatic brain injury and glioblastoma is suggested; this role may support a cause-and-effect link with the subsequent development of glioblastoma.

Filament Fragmentation Phenomena

1989 ◽  
Vol 170 ◽  
Author(s):  
Juan C. Figueroa ◽  
Linda S. Schadler ◽  
Campbell Laird
Keyword(s):  
Strain Energy ◽  
Stress Transfer ◽  
Fiber Surface ◽  
Yield Information ◽  
The Matrix ◽  
Two Parameters ◽  
The Relationship

AbstractThe effect of fiber surface treatments on the relationship between the tensile strength of a filament and the shear strength of its interphase is one of the central issues facing composite materials technologists today. We demonstrate here that analysis of fragmentation phenomena in monofilament composites can simultaneously yield information about these two parameters. Characterization of shear stress transfer zones in non-critical fragments has led us to the determination of interphase strength.A phenomenological treatment that highlights the role of the matrix in the fragmentation process is presented here. This analysis considers issues such as the strain energy exchange between a failing fiber and the matrix, as well as interphase relaxation due to the viscoelastic nature of the matrix. Our observations of the fragmentation phenomena in AU4/polycarbonate monofilament composites indicate that the fiber/matrix interaction in this system is governed by micromechanical locking.

The Elephant in the Schoolhouse

2017 ◽  
Vol 90 (2) ◽  
pp. 149-171 ◽  
Author(s):  
James P. Spillane ◽  
Matthew Shirrell ◽  
Tracy M. Sweet
Keyword(s):  
Social Ties ◽  
Careful Consideration ◽  
School Staff ◽  
Sociological Research ◽  
Physical Proximity ◽  
Work Related ◽  
Advice Seeking ◽  
Research In Education ◽  
The Relationship

Although the physical arrangement of workspaces can both constrain and enable interactions among organizational members, sociological research in education has not extensively examined the role of physical proximity in determining work-related social ties among school staff. Using social network analysis, this article explores the relationship between physical proximity and instructional advice seeking among school staff in all 14 elementary schools in one U.S. school district over four years. Results show that school staff whose workspaces are located closer to one another, and whose paths likely cross more frequently in their day-to-day work within the school building, are more likely to talk with one another about their work. Findings argue for more careful consideration when assigning school staff to workspaces, as the physical proximity of school staff appears to play a significant role in who talks to whom about instruction.

scholarly journals Characterization of tabanid flies (Diptera: Tabanidae) in South Africa and Zambia and detection of protozoan parasites they are harbouring

Parasitology ◽  
2017 ◽  
Vol 144 (9) ◽  
pp. 1162-1178 ◽  
Author(s):  
MOETI O. TAIOE ◽  
MAKHOSAZANA Y. MOTLOANG ◽  
BONIFACE NAMANGALA ◽  
AMOS CHOTA ◽  
NTHATISI I. MOLEFE ◽  
...  
Keyword(s):  
South Africa ◽  
South African ◽  
Trypanosoma Evansi ◽  
Protozoan Parasites ◽  
Babesia Bigemina ◽  
Relationship Of ◽  
The Relationship ◽  
Trypanosoma Theileri

SUMMARYTabanids are haematophagous flies feeding on livestock and wildlife. In the absence of information on the relationship of tabanid flies and protozoan parasites in South Africa and Zambia, the current study was aimed at characterizing tabanid flies collected in these two countries as well as detecting protozoan parasites they are harbouring. A total of 527 tabanid flies were collected whereby 70·2% were from South Africa and 29·8% were from Zambia. Morphological analysis revealed a total of five different genera collected from the sampled areas namely:Ancala, Atylotus, Haematopota, PhilolicheandTabanus. DNA extracted from South AfricanTabanus parandTabanus taeniolatested positive for the presence ofTrypanosoma congolense(Savannah) andTrypanosoma theileriwhilst one member fromT. parwas positive forTrypanosoma bruceispecies. DNA extracted from Zambian tabanid flies tested positive for the presence ofBesnoitiaspecies at 1·27% (2/157),Babesia bigemina5·73% (9/157),Theileria parva30·11% (30/157) and 9·82% (14/157) forTrypanosoma evansi. This study is the first to report on relationship ofBabesiaandTheileriaparasites with tabanid flies. Further investigations are required to determine the role of tabanids in transmission of the detected protozoan parasites in livestock and wildlife in South Africa and Zambia.

Characterization of actionable genetic alterations to guide targeted therapy for metastatic urothelial carcinoma.

2019 ◽  
Vol 37 (7_suppl) ◽  
pp. 407-407
Author(s):  
Nima Almassi ◽  
Eugene J. Pietzak ◽  
Samuel Aaron Funt ◽  
Nikolaus Schultz ◽  
Guido Dalbagni ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
Urothelial Carcinoma ◽  
Genetic Alterations ◽  
Level Of Evidence ◽  
Active Interest ◽  
Metastatic Urothelial Carcinoma ◽  
Brca1 Brca2 ◽  
The Relationship

407 Background: Genetic alterations predicting response to targeted therapy are an area of active interest in developing novel therapies for patients with metastatic urothelial carcinoma (mUC). With the objective of characterizing the frequency of actionable alterations (AA) and the evidence supporting targeted therapy for these AAs, we report our experience with next-generation sequencing in mUC. Methods: Patients with sequenced mUC lesions were identified from our prospectively-maintained database. All AAs with clinical or biologic evidence supporting the alteration as predicting response to targeted therapy were identified and stratified by Oncology Knowledge Base (OncoKB) level of evidence (table). The relationship between strength of evidence and administration of targeted therapy was examined. Results: Ninety-nine of 134 patients (74%) harbored at least one AA, with 162 total AAs identified. Twenty level 2B AAs were identified, reflecting the highest level evidence in this cohort, with ERBB2 amplification (9), TSC1/TSC2 (6), and BRCA1/BRCA2 mutations (3) most common. Twenty-eight level 3A, 51 level 3B, and 62 level 4 AAs were also identified. Seventeen patients received targeted therapy, which was administered with greater frequency among patients with level 3B or higher AAs (21% vs 3%). Conclusions: Most patients with mUC harbor at least one AA, suggesting multiple targeted therapeutic opportunities in mUC. These findings highlight the need for additional clinical trials and the role of genetic testing in identifying candidates for targeted therapy. [Table: see text]

scholarly journals Co-occurrence of analogous enzymes determines evolution of a novel (βα)8-isomerase sub-family after non-conserved mutations in flexible loop

2016 ◽  
Vol 473 (9) ◽  
pp. 1141-1152 ◽  
Author(s):  
Ernesto A. Verduzco-Castro ◽  
Karolina Michalska ◽  
Michael Endres ◽  
Ana L. Juárez-Vazquez ◽  
Lianet Noda-García ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Isomerase Activity ◽  
Corynebacterium Species ◽  
Missing Gene ◽  
The Relationship ◽  
Substrate Affinities ◽  
Dual Substrate

We investigate the evolution of co-occurring analogous enzymes involved in L-tryptophan and L-histidine biosynthesis in Actinobacteria. Phylogenetic analysis of trpF homologues, a missing gene in certain clades of this lineage whose absence is complemented by a dual-substrate HisA homologue, termed PriA, found that they fall into three categories: (i) trpF-1, an L-tryptophan biosynthetic gene horizontally acquired by certain Corynebacterium species; (ii) trpF-2, a paralogue known to be involved in synthesizing a pyrrolopyrrole moiety and (iii) trpF-3, a variable non-conserved orthologue of trpF-1. We previously investigated the effect of trpF-1 upon the evolution of PriA substrate specificity, but nothing is known about the relationship between trpF-3 and priA. After in vitro steady-state enzyme kinetics we found that trpF-3 encodes a phosphoribosyl anthranilate isomerase. However, mutation of this gene in Streptomyces sviceus did not lead to auxothrophy, as expected from the biosynthetic role of trpF-1. Biochemical characterization of a dozen co-occurring TrpF-2 or TrpF-3, with PriA homologues, explained the prototrophic phenotype, and unveiled an enzyme activity trade-off between TrpF and PriA. X-ray structural analysis suggests that the function of these PriA homologues is mediated by non-conserved mutations in the flexible L5 loop, which may be responsible for different substrate affinities. Thus, the PriA homologues that co-occur with TrpF-3 represent a novel enzyme family, termed PriB, which evolved in response to PRA isomerase activity. The characterization of co-occurring enzymes provides insights into the influence of functional redundancy on the evolution of enzyme function, which could be useful for enzyme functional annotation.

The role of initial and final states in molecular spectroscopies

2019 ◽  
Vol 21 (24) ◽  
pp. 12730-12747 ◽  
Author(s):  
Tino Kirchhuebel ◽  
Oliver L. A. Monti ◽  
Toshiaki Munakata ◽  
Satoshi Kera ◽  
Roman Forker ◽  
...  
Keyword(s):  
Experimental Data ◽  
Thin Films ◽  
Organic Semiconductors ◽  
Careful Consideration ◽  
Spectroscopic Techniques ◽  
Final States ◽  
The Relationship

Interpreting experimental spectra of thin films of organic semiconductors is challenging, and understanding the relationship between experimental data obtained by different spectroscopic techniques requires a careful consideration of the initial and final states for each process.

The leucine-responsive regulatory protein (lrp) gene for characterization of the relationship among Xanthomonas species

2004 ◽  
Vol 54 (2) ◽  
pp. 429-437 ◽  
Author(s):  
Jaime Cubero ◽  
James H. Graham
Keyword(s):  
Xanthomonas Campestris ◽  
Regulatory Protein ◽  
Amino Acid Level ◽  
Gene Sequences ◽  
Xanthomonas Species ◽  
Entire Sequence ◽  
The Relationship

Characterization of strains of Xanthomonas axonopodis pv. citri by using DNA fingerprints that were generated from primers for enterobacterial repetitive intergenic consensus (ERIC) elements led to the discovery of differential sequences for a leucine-responsive regulatory protein (lrp) gene in two subgroups of strains with different host ranges on Citrus spp. DNA hybridization and PCR-based assays that used different sets of primers were designed to detect the core sequence, as well as to obtain the entire sequence of the lrp gene for several Xanthomonas species and pathovars. Higher variability was observed at the nucleotide level than at the amino acid level among the different species and pathovars, revealing selection pressure on the lrp gene, which is presumably due to an essential role of the gene in bacterial metabolism. Moderate variability in the 3′ and 5′ domains was used to study relationships among different species within the genus Xanthomonas. Species of this genus that were isolated from citrus, as well as other pathovars of X. axonopodis, showed highly similar lrp gene sequences, whereas other Xanthomonas species, especially Xanthomonas campestris, had sequences that were more dissimilar to that of X. axonopodis. Thus, the lrp gene sequence is useful to distinguish X. axonopodis pv. citri groups and promising for polyphasic taxonomic analysis of the genus Xanthomonas. Data from analysis of lrp gene sequences support the current concepts for classification of xanthomonads, which are based on other approaches.

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