Compositional Closure—Its Origin Lies Not in Mathematics but Rather in Nature Itself

Compositional closure, spurious negative correlations in data sets of a fixed sum (e.g., fractions and percent), is often encountered in geostatistical analyses, particularly in mineralogy, petrology, and geochemistry. Techniques to minimize the effects of closure (e.g., log-ratio transformations) can provide consistent geostatistical results. However, such approaches do not remove these effects because closure does not result from mathematical operations but is an inherent property of the physical systems under study. The natural world causes physical closure; mathematics simply describes that closure and cannot alter it by manipulations. Here, we examine the distinct types of geologic systems and samples to determine in which situations closure (physical and mathematical) does or does not ensue and the reasons therefor. We parse compositional systems based on (1) types of components under study, immutable (e.g., elements) or reactive (minerals), and (2) whether the system is open or closed to component transfer. Further, open systems can be (1) displacive in which addition of a component physically crowds out others, or (2) accommodative in which addition or subtraction of components does not affect the others. Only displacive systems are subject to compositional closure. Accommodative systems, even with components expressed as percent or fractions, are not closed physically or, therefore, mathematically.

Phase Noise Characterization in Phase-Sensitive OTDR Systems

<div>Coherent detected phase-OTDR (CDPO) systems are mainly used in distributed vibration sensing and these systems are preferred over the direct detected phase-OTDR (DDPO) systems due to their inherent property of mitigating a certain type of phase noise. There is a possibility that the existing non-mitigated phase noise can be controlled in CDPO systems only after properly investigating the characteristics of both the CDPO mitigated and CDPO-non-mitigated noise types. Hence, the first and crucial step, i.e, the characteristics of two different phase noise types are determined in this paper. This determination will help in providing ease about finding the real sources of both of the phase noise types and hence can help in mitigating the existing phase noise further.</div>

Phase Noise Characterization in Phase-Sensitive OTDR Systems

<div>Coherent detected phase-OTDR (CDPO) systems are mainly used in distributed vibration sensing and these systems are preferred over the direct detected phase-OTDR (DDPO) systems due to their inherent property of mitigating a certain type of phase noise. There is a possibility that the existing non-mitigated phase noise can be controlled in CDPO systems only after properly investigating the characteristics of both the CDPO mitigated and CDPO-non-mitigated noise types. Hence, the first and crucial step, i.e, the characteristics of two different phase noise types are determined in this paper. This determination will help in providing ease about finding the real sources of both of the phase noise types and hence can help in mitigating the existing phase noise further.</div>

La vaguedad y la precisión: Ejercicios de elasticidad lingüística

La vaguedad es una propiedad inherente de las lenguas naturales y, también, una estrategia discursiva eficaz. En este trabajo se presta atención a los rasgos de la vaguedad lingüística, a los motivos que justifican su existencia, a los tipos de vaguedad y a la relación que se establece con otros procesos semánticos como la polisemia, la homonimia o la modalidad epistémica. La vaguedad intencional (la que persigue un fin comunicativo) ha de enmarcarse dentro del contínuum precisión-imprecisión. En el ámbito de la vaguedad intencional ha de distinguirse una vaguedad pragmática (generada por el contexto) y otra vaguedad lingüística, consistente en el empleo de elementos lingüísticos que estrechan el margen de precisión o amplían el espectro de la vaguedad. La posibilidad de que el emisor pueda intervenir en el grado de precisión o imprecisión de una expresión lingüística pone de manifiesto la elasticidad del idioma. Vagueness is an inherent property of natural languages ​​and also an effective discursive strategy. In this work attention to features of linguistic vagueness, the reasons for their existence, the types of vagueness and the relationship established with other semantic processes such as polysemy, homonyms or epistemic modality is provided. The intentional vagueness (which pursues a communicative purpose) must fit within the continuum of precision-vagueness. In the field of intentional vagueness we have to distinguish a pragmatic vagueness (generated by the context) and other linguistic vagueness, consisting of the use of linguistic elements that narrow the margin of precision or broaden the spectrum of vagueness. The possibility that the speaker may select the degree of accuracy or inaccuracy of a linguistic expression shows the elasticity of language.

Competitive Failure of Loosening and Fatigue of Bolts under Composite Excitation

At present, research on the loosening of bolts under transverse excitation and their fatigue under axial excitation has been relatively mature, but research on the competitive relationship and failure characteristics between loosening and fatigue of bolts under transverse and axial composite excitation is still insufficient. Therefore, a method to accurately determine the failure types of bolts is proposed in this study by conducting a competitive failure test of loosening and fatigue under composite excitation. According to this method, the failure types of bolts can be distinguished. The analysis results reveal that there is an obvious competitive failure relationship between the loosening and fatigue of bolts, and the failure mode is mainly affected by the ratio of the transverse and axial loads (ξ). There is a critical ξ of bolt-loosening or fatigue failure, and the critical ξ is an inherent property of the bolt and is unrelated to the load. The critical ξ of 8.8 grade M8 × 1.25 × 70 high-strength bolts under composite excitation is obtained as 0.075 mm/kN. The failure mode of bolts under composite excitation can be predicted based on the critical ξ.

Rotation Rate Sensors and Their Applications

Measurements of rotations are unique because of their inherent property making them absolute and without an external frame of reference [...]

Neural entrainment facilitates duplets: Frequency-tagging differentiates musicians and non-musicians when they tap to the beat

ABSTRACTMotor coordination to an isochronous beat improves when it is subdivided into equal intervals. Here, we study if this subdivision benefit (i) varies with the kind of subdivision, (ii) is enhanced in individuals with formal musical training, and (iii), is an inherent property of neural oscillations. We recorded electroencephalograms of musicians and non-musicians during: (a) listening to an isochronous beat, (b) listening to one of 4 different subdivisions, (c) listening to the beat again, and (d) listening and tapping the beat with the same subdivisions as in (b). We found that tapping consistency and neural entrainment in condition (d) was enhanced in non-musicians for duplets (1:2) compared to the other types of subdivisions. Musicians showed overall better tapping performance and were equally good at tapping together with duplets, triplets (1:3) and quadruplets (1:4), but not with quintuplets (1:5). This group difference was reflected in enhanced neural responses in the triplet and quadruplet conditions. Importantly, for all participants, the neural entrainment to the beat and its first harmonic (i.e. the duplet frequency) increased after listening to each of the subdivisions (c compared to a). Since these subdivisions are harmonics of the beat frequency, the observed preference of the brain to enhance the simplest subdivision level (duplets) may be an inherent property of neural oscillations. In sum, a tapping advantage for simple binary subdivisions is reflected in neural oscillations to harmonics of the beat, and formal training in music can enhance it.Highlights-The neural entrainment to periodic sounds only differs between musicians and non-musicians when they perform a predictive sensorimotor synchronization task.-After listening to a subdivided beat, the frequencies related to the beat and its first harmonic are enhanced in the EEG, likely stabilizing the perception of the beat.-There is a natural advantage for binary structures in sensorimotor synchronization, observed in the tapping of duplets by non-musicians, which can be extended to other subdivisions after extensive musical training.

Type IV pili share a conserved mechanism of motor-independent retraction that is an inherent property of the pilus filament

ABSTRACTType IV pili (T4P) are dynamic surface appendages that promote virulence, biofilm formation, horizontal gene transfer, and motility in diverse bacterial species. Pilus dynamic activity is best characterized in T4P that use distinct ATPase motors for pilus extension and retraction. Many T4P systems, however, lack a dedicated retraction motor and the mechanism underlying this motor-independent retraction remains a mystery. Using the Vibrio cholerae competence pilus as a model system, we identify mutations in the major pilin gene that enhance motor-independent retraction. These mutants produced less stable pili, likely due to diminished pilin-pilin interactions within the filament. One mutation adds a bulky residue to α1C, a universally conserved feature of type IV pilins. We found that inserting a bulky residue into α1C of the retraction motor-dependent Acinetobacter baylyi com-petence T4P is sufficient to induce motor-independent retraction. Conversely, removing bulky residues from α1C of the retraction motor-independent V. cholerae toxin-co-regulated T4P stabilizes the filament and prevents retraction. Furthermore, alignment of pilins from the broader type IV filament (T4F) family indicated that retraction motor-independent T4P, Com pili, and type II secretion systems generally encode larger residues within α1C oriented toward the pilus core compared to retraction motor-dependent T4P. Together, our data demonstrate that motor-independent retraction relies on the inherent instability of the pilus filament that may be conserved in diverse T4Fs. This provides the first evidence for a long-standing, yet untested, model in which pili retract in the absence of a motor by spontaneous de-polymerization.SIGNIFICANCEExtracellular pilus filaments are critical for the virulence and persistence of many bacterial pathogens. A crucial property of these filaments is their ability to dynamically extend and retract from the bacterial surface. A detailed mechanistic understanding of pilus retraction, however, remains lacking in many systems. Here, we reveal that pilus retraction is an inherent property of the pilus filament. These observations are broadly relevant to diverse pilus systems, including those in many bacterial pathogens, and may help inform novel therapeutic strategies that aim to target pilus dynamic activity.

Quiet Politics and the Power of Business: New Perspectives in an Era of Noisy Politics

This introduction summarizes the main contributions of this special issue titled “Quiet Politics and the Power of Business: New Perspectives in an Era of Noisy Politics.” The four articles in the issue use and extend Culpepper’s influential concept of “quiet politics” according to which business is able to shape policies and regulations when issues are of low salience to the public and politicians. The issue takes Culpepper’s analysis further in ways that respond to the rise of noisy politics over the last few years, often associated with new strident forms of left- and right-wing populism. Three contributions are made. First, the articles show that salience is not an inherent property of a policy area but is socially constructed. Second, a variety of strategies are described that business uses when trying to keep politics quiet. Third, strategies are affected by the structure of business, which varies across types of capitalism. Future research can use these insights to extend our understanding of the limits, strategies, and dynamics of quiet politics across political economies.

Simultaneous Transmit and Receive with Shared-Aperture Arrays

An approach based on shared aperture antenna array is researched for simultaneous transmit and receive (STAR) applications. The proposed configuration is a 10×10 antenna array of circularly-polarized (CP) elements with 50 elements, somewhat sparsely distributed, dedicated for Tx while the remaining elements dedicated for Rx. The high isolation is achieved between Tx and Rx elements at the expense of higher sidelobe levels, which is an inherent property of sparse antenna arrays. To demonstrate the performance of the proposed STAR configuration, numerical modelling is conducted using multilevel fast multipole method (MLFMM) solver in Altair FEKO.