Time and Interrogative Logical Form

Philosophy ◽  
2001 ◽  
Vol 76 (1) ◽  
pp. 55-75
Author(s):  
James Somerville

Despite some talk of ‘erotetic logic’ and ‘the logic of interrogatives’, logicians have hitherto completely overlooked the peculiar logical form of questions, also shared by interrogative clauses generally. Of relevance to an understanding of time are those interrogative clauses that are janus-like: sometimes raising a question, sometimes answering it—which can then no longer arise. Since a closed question can no longer arise, it might seem that simply the passing of time turns an open into a closed question. Instead, the passing of time itself can be understood as the closing or resolution of open questions, of the determination of what is not fixed but as yet in question.

2019 ◽  
Vol 621 ◽  
pp. A92 ◽  
Author(s):  
A. A. C. Sander ◽  
W.-R. Hamann ◽  
H. Todt ◽  
R. Hainich ◽  
T. Shenar ◽  
...  

Wolf-Rayet stars of the carbon sequence (WC stars) are an important cornerstone in the late evolution of massive stars before their core collapse. As core-helium burning, hydrogen-free objects with huge mass-loss, they are likely the last observable stage before collapse and thus promising progenitor candidates for type Ib/c supernovae. Their strong mass-loss furthermore provides challenges and constraints to the theory of radiatively driven winds. Thus, the determination of the WC star parameters is of major importance for several astrophysical fields. With Gaia DR2, for the first time parallaxes for a large sample of Galactic WC stars are available, removing major uncertainties inherent to earlier studies. In this work, we re-examine a previously studied sample of WC stars to derive key properties of the Galactic WC population. All quantities depending on the distance are updated, while the underlying spectral analyzes remain untouched. Contrasting earlier assumptions, our study yields that WC stars of the same subtype can significantly vary in absolute magnitude. With Gaia DR2, the picture of the Galactic WC population becomes more complex: We obtain luminosities ranging from logL/L⊙ = 4.9–6.0 with one outlier (WR 119) having logL/L⊙ = 4.7. This indicates that the WC stars are likely formed from a broader initial mass range than previously assumed. We obtain mass-loss rates ranging between log Ṁ = −5.1 and −4.1, with Ṁ ∝ L0.68 and a linear scaling of the modified wind momentum with luminosity. We discuss the implications for stellar evolution, including unsolved issues regarding the need of envelope inflation to address the WR radius problem, and the open questions in regard to the connection of WR stars with Gamma-ray bursts. WC and WO stars are progenitors of massive black holes, collapsing either silently or in a supernova that most-likely has to be preceded by a WO stage.


2019 ◽  
Vol 12 ◽  
pp. 02030 ◽  
Author(s):  
C. Fauhl-Hassek

Important challenges of wine authentication - for example the proof of wine varieties, the determination of the vintage or the geographical origin, the determination of certain practices (e.g. differentiation of barrel/chips storage) become more and more successfully investigated by non-targeted analytical approaches. Not only in relation to these open questions in wine authentication non-targeted approaches such as nuclear magnetic resonance and mass spectrometry offer enormous potential also in wine authentication due to their typical abilities as high-through put and screening technique. The adaptation from research into routine applications takes actually place in some instances (e.g. NMR) including wine analysis. In addition the combination of non-targeted and targeted approaches within the same run of analysis provides possibilities complementing or even substituting classical methodologies. Some examples, the general workflow and typical evaluation strategies will be presented and their possibilities and limits discussed. First results of a recent study on the NMR analysis with focus on variety verification and reproducibility of spectral data will be presented. Particular emphasis will be put on general open questions such as exchangeability of data, validation, standardisation options.


2021 ◽  
Vol 7 (1) ◽  
pp. 63-73
Author(s):  
Yuswa Istikomayanti ◽  
Zuni Mitasari

Ethnic and natural environments coexist together. However, along with the development of modernization to various corners of the region also makes challenges for indigenous peoples to remain in the future. The purpose of this study is to describe ethnobotany values ​​in the Sumba millennial generation and to examine the socio-ecological aspects as a new perspective in ethnobotany studies. Sumba millennials are students of the Tribhuwana Tunggadewi University who are regional children who still live with a cultural environment, especially the Sumba area, East Nusa Tenggara. Through questionnaires, open questions and in-depth interviews with key respondents, it can be assessed the extent to which cultural values ​​exist in the Sumba millennial generation who have received education and modern life. Socio-ecological studies are important to be carried out as a perspective in making various policy directions. Particularly in the direction of education, selection, and determination of customary values ​​and how efforts to conserve them become co-existent ethnicities and environments. The results obtained by most of the millennial generation still hold customary values ​​in their daily behavior. This aspect is reflected in the use of traditional medicine, skills in weaving, natural coloring, eating betel-nut, and positive perceptions of the preservation of its culture in the future.  Keywords:Ethnobotany, Indonesia, Milenial, Sumba, Socio-Ecology ABSTRAK Etnis dan lingkungan alam hidup berdampingan. Namun, dengan seiring berkembangnya modernisasi hingga ke berbagai pelosok daerah juga menjadikan tantangan untuk masyarakat adat tetap bertahan di masa depan. Tujuan penelitian ini untuk mendeskripsikan nilai-nilai etnobotani pada generasi milenial Sumba serta mengkaji aspek sosio-ekologi sebagai perspektif baru dalam kajian etnobotani. Milenial Sumba yaitu mahasiswa Universitas Tribhuwana Tunggadewi yang merupakan anak daerah yang masih hidup dengan lingkungan kebudayaan khususnya daerah Sumba, Nusa Tenggara Timur. Melalui kuesioner, pertanyaan terbuka serta wawancara mendalam pada responden kunci dapat dikaji sejauh mana nilai-nilai kebudayaan yang ada pada generasi milenial Sumba yang telah mengenyam pendidikan dan kehidupan modern di Kota Malang, Jawa Timur, Indonesia. Kajian sosio-ekologi menjadi penting untuk dilakukan sebagai perspektif dalam pengambilan arah berbagai kebijakan. Khususnya dalam arah pendidikan, pemilihan, dan penentuan nilai-nilai adat dan bagaimana upaya pelestariannya menjadi etnis dan lingkungan yang saling berdampingan. Hasil yang diperoleh sebagian besar generasi milenial masih memegang nilai adat dalam perilakunya sehari-hari. Aspek tersebut tercermin dalam penggunaan obat tradisional, keterampilan menenun, mewarnai secara alami, makan sirih-pinang, serta persepsi positif terhadap kelestarian budayanya di masa depan. Kata kunci: etnobotani, Indonesia, milenial, Sumba, Sosio-Ekologi


2016 ◽  
Vol 9 ◽  
pp. GEI.S37925 ◽  
Author(s):  
Fredj Tekaia

With the increasing number of sequenced genomes and their comparisons, the detection of orthologs is crucial for reliable functional annotation and evolutionary analyses of genes and species. Yet, the dynamic remodeling of genome content through gain, loss, transfer of genes, and segmental and whole-genome duplication hinders reliable orthology detection. Moreover, the lack of direct functional evidence and the questionable quality of some available genome sequences and annotations present additional difficulties to assess orthology. This article reviews the existing computational methods and their potential accuracy in the high-throughput era of genome sequencing and anticipates open questions in terms of methodology, reliability, and computation. Appropriate taxon sampling together with combination of methods based on similarity, phylogeny, synteny, and evolutionary knowledge that may help detecting speciation events appears to be the most accurate strategy. This review also raises perspectives on the potential determination of orthology throughout the whole species phylogeny.


2021 ◽  
Vol 22 (2) ◽  
pp. 533
Author(s):  
Adéla Tiffner ◽  
Lena Maltan ◽  
Sarah Weiß ◽  
Isabella Derler

Cell survival and normal cell function require a highly coordinated and precise regulation of basal cytosolic Ca2+ concentrations. The primary source of Ca2+ entry into the cell is mediated by the Ca2+ release-activated Ca2+ (CRAC) channel. Its action is stimulated in response to internal Ca2+ store depletion. The fundamental constituents of CRAC channels are the Ca2+ sensor, stromal interaction molecule 1 (STIM1) anchored in the endoplasmic reticulum, and a highly Ca2+-selective pore-forming subunit Orai1 in the plasma membrane. The precise nature of the Orai1 pore opening is currently a topic of intensive research. This review describes how Orai1 gating checkpoints in the middle and cytosolic extended transmembrane regions act together in a concerted manner to ensure an opening-permissive Orai1 channel conformation. In this context, we highlight the effects of the currently known multitude of Orai1 mutations, which led to the identification of a series of gating checkpoints and the determination of their role in diverse steps of the Orai1 activation cascade. The synergistic action of these gating checkpoints maintains an intact pore geometry, settles STIM1 coupling, and governs pore opening. We describe the current knowledge on Orai1 channel gating mechanisms and summarize still open questions of the STIM1–Orai1 machinery.


2021 ◽  
Author(s):  
Benoît Pasquier ◽  
Sophia K. V. Hines ◽  
Hengdi Liang ◽  
Yingzhe Wu ◽  
Seth G. John ◽  
...  

Abstract. Spatially distant sources of neodymium (Nd) to the ocean that carry different isotopic signatures (εNd) have been shown to trace out major water masses, and have thus been extensively used to study large-scale features of the ocean circulation both past and current. While the global marine Nd cycle is qualitatively well understood, a complete quantitative determination of all its components and mechanisms, such as the magnitude of its sources and the paradoxical conservative behavior of εNd, remains elusive. To make sense of the increasing collection of observational Nd and εNd data, we develop the global neodymium ocean model (GNOM) v1, the first inverse model of the global marine biogeochemical cycle of Nd. The GNOM is embedded in a data-constrained steady-state circulation that affords spectacular computational efficiency, which we leverage to estimate biogeochemical parameters via systematic objective optimization. Owing to its matrix representation, the GNOM model is additionally amenable to novel diagnostics that allow us to investigate open questions about the Nd cycle with unprecedented accuracy. The GNOM is open-source and freely accessible, is written in Julia, and its code is easily understandable and modifiable for further developments and experiments.


2020 ◽  
Vol 216 (8) ◽  
Author(s):  
Iannis Dandouras ◽  
Michel Blanc ◽  
Luca Fossati ◽  
Mikhail Gerasimov ◽  
Eike W. Guenther ◽  
...  

AbstractIn this chapter, we review the contribution of space missions to the determination of the elemental and isotopic composition of Earth, Moon and the terrestrial planets, with special emphasis on currently planned and future missions. We show how these missions are going to significantly contribute to, or sometimes revolutionise, our understanding of planetary evolution, from formation to the possible emergence of life. We start with the Earth, which is a unique habitable body with actual life, and that is strongly related to its atmosphere. The new wave of missions to the Moon is then reviewed, which are going to study its formation history, the structure and dynamics of its tenuous exosphere and the interaction of the Moon’s surface and exosphere with the different sources of plasma and radiation of its environment, including the solar wind and the escaping Earth’s upper atmosphere. Missions to study the noble gas atmospheres of the terrestrial planets, Venus and Mars, are then examined. These missions are expected to trace the evolutionary paths of these two noble gas atmospheres, with a special emphasis on understanding the effect of atmospheric escape on the fate of water. Future missions to these planets will be key to help us establishing a comparative view of the evolution of climates and habitability at Earth, Venus and Mars, one of the most important and challenging open questions of planetary science. Finally, as the detection and characterisation of exoplanets is currently revolutionising the scope of planetary science, we review the missions aiming to characterise the internal structure and the atmospheres of these exoplanets.


2017 ◽  
Vol 9 (2) ◽  
pp. 570
Author(s):  
Rafael Arenas García

Resumen: La sentencia KA Finanz ofrece al Tribunal de Luxemburgo la oportunidad de pronunciarse sobre varias cuestiones relevantes en materia de fusiones internacionales. En concreto sobre las relaciones entre el Derecho rector de las obligaciones de las que son parte las sociedades que intervienen en la fusión y la que se aplica a este operación; la determinación del Derecho rector de la fusión y ciertos límites en las posibilidades de regular las garantías de los acreedores en las fusiones internacionales. Además, interpreta qué ha de entenderse por titulares de títulos a los que correspondan derechos especiales (art. 15 de la Directiva 78/855/CEE).Palabras clave: Derecho de sociedades, libertad de establecimiento, fusiones internacionales, protección de los acreedores.Abstract: The KA Finanz judgment allows the Luxembourg Court to deal with some relevant issues connected to international mergers. Specifically, on the relationship between the laws governing the obligations of which the companies involved in the merger are parties, and the one that applies to the merger; the determination of the law governing the merger and also on certain limits of the national legislators in the regulation of the creditor’s guarantees in international mergers. Furthermore, it interprets what is to be understood by holders of securities to which special rights are attached (article 15 of Directive 78/855 / EEC).Keywords: Company law, freedom of establishment, international mergers, protection of the interest of creditors.


2015 ◽  
Vol 11 (A29B) ◽  
pp. 552-559
Author(s):  
Konstanze Zwintz

AbstractAsteroseismology has been proven to be a successful tool to unravel details of the internal structure for different types of stars in various stages of evolution well after birth. We can now show that it has similar power for pre-main sequence (pre-MS) objects. Pre-MS stars with masses between ~1 and 6 solar masses that have recently been formed and gain their energy mainly from gravitational contraction can become vibrationally unstable during their evolution to the main sequence. Within the past ~15 years, several dozens of pulsating pre-MS stars were discovered using data obtained from ground and from space. Depending on their masses, pre-MS stars can show three different types of pulsations: (i) δ Scuti type p-mode pulsations, (ii) γ Doradus like g-mode oscillations and (iii) g-mode Slowly Pulsating B star pulsations.Our asteroseismic investigations yielded new insights into the connection between the pulsations and early stellar evolution: We revealed a relation between the stars' oscillatory behavior and their relative evolutionary stages that might lead us to a model-independent determination of the stars' fundamental parameters. With this we will be able to put constraints on theoretical models and help to answer some of the yet open questions in early stellar evolution.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3036
Author(s):  
Tobias Münster ◽  
Peter Werle ◽  
Kai Hämel ◽  
Jörg Preusel

The article presents issues related to the aging behavior of oil-paper insulations in transformers using different oil- and ester-based insulating fluids. Despite numerous conducted studies on the subject of oil-paper aging, the use of new insulating fluids is creating open questions. In addition, new liquids such as synthetic and natural esters, as well as oil of the newest generation, are being used. Furthermore, there is still little research on the formation of aging markers with this form of the dielectric. For this reason, in this contribution, oil-paper insulations with mineral oil-based insulating fluids, natural and synthetic esters, as well as oil from natural gas, are aged thermally accelerated at 130 °C over a duration of 15 weeks, by considering two cases of free-breathing and hermetically sealed transformers. Therefore, various aging markers are investigated to allow a condition assessment. The results show that differences exist between the fluids and design of the transformer, as in the aging rate of the paper and the formation of aging markers in the insulating liquid such as acids. These findings can be used to improve asset management strategies by a more precise determination of the aging state depending on the transformer type as well as the type of insulating fluid.


Sign in / Sign up

Export Citation Format

Share Document