Active tail flexion in concert with passive hydrodynamic forces improves swimming speed and efficiency

Fish typically swim by periodic bending of their bodies. Bending seems to follow a universal rule; it occurs at about one-third from the posterior end of the fish body with a maximum bending angle of about $30^{\circ }$ . However, the hydrodynamic mechanisms that shaped this convergent design and its potential benefit to fish in terms of swimming speed and efficiency are not well understood. It is also unclear to what extent this bending is active or follows passively from the interaction of a flexible posterior with the fluid environment. Here, we use a self-propelled two-link model, with fluid–structure interactions described in the context of the vortex sheet method, to analyse the effects of both active and passive body bending on the swimming performance. We find that passive bending is more efficient but could reduce swimming speed compared with rigid flapping, but the addition of active bending could enhance both speed and efficiency. Importantly, we find that the phase difference between the posterior and anterior sections of the body is an important kinematic factor that influences performance, and that active antiphase flexion, consistent with the passive flexion phase, can simultaneously enhance speed and efficiency in a region of the design space that overlaps with biological observations. Our results are consistent with the hypothesis that fish that actively bend their bodies in a fashion that exploits passive hydrodynamics can at once improve speed and efficiency.

Rethinking the Proportional Design Principles of Timber-Framed Buddhist Buildings in the Goryeo Era

This study examines how the wooden architecture of the Goryeo Dynasty in Korea evolved in an original way while incorporating Chinese architectural principles. For the Goryeo Era’s timber-framed buildings, eave purlin height was determined according to √2H times the eave column height (H), while the eave column height influenced the proportional location of each purlin, determined by the √2H times decrease rate in the cross-section. Thus, eave column height was proportionately connected to a geometric sequence with a common ratio of √2H. This technical approach, achieved using an L-square ruler and a drawing compass, contributed to determining eave purlin and ridge post placement, bracket system height, and outermost bay width. This study notes that the practical works were consistently preserved in East Asian Buddhist architecture, in that a universal rule of proportion was applied to buildings constructed during the Tang–Song and the Goryeo Dynasties, surmounting differences in local construction methods. These design principles were a vestige of socio-cultural exchange on the East Asian continent and a minimal step toward the establishment of structurally safe framed buildings.

Universal Rule for Covid 19 and Herd Immunity in the US

A new Universal rule for Covid 19 data is derived in this paper using the SIR model.It relates infection and removal rates and is validated by the global Covid 19 data. Over 186,000 data points, from 190 countries and the states of the US, for the period April 1 to December 12, 2020 - fall on a single line, as the Universal rule predicts, transcending geography, ethnicity and race.The Universal rule requires that Herd immunity begin when just 25% of the population is vaccinated. With the anticipated 100 million vaccinations in the first 100 days of the Biden administration, Herd immunity may be imminent in the US.The Universal rule promotes a temporary stasis with continuing infections and hospitalizations and becomes a barrier to runaway infections, making it practically impossible to reach Herd immunity, as Sweden discovered. Reduced infected population seems to be a third option to stifle the epidemic - a little known accomplishment, first by North Dakota and subsequently by twelve other U.S. states, including South Dakota.

Effect of Concentrated Salts Solutions on the Stability of Immobilized Enzymes: Influence of Inactivation Conditions and Immobilization Protocol

This paper aims to investigate the effects of some salts (NaCl, (NH4)2SO4 and Na2SO4) at pH 5.0, 7.0 and 9.0 on the stability of 13 different immobilized enzymes: five lipases, three proteases, two glycosidases, and one laccase, penicillin G acylase and catalase. The enzymes were immobilized to prevent their aggregation. Lipases were immobilized via interfacial activation on octyl agarose or on glutaraldehyde-amino agarose beads, proteases on glyoxyl agarose or glutaraldehyde-amino agarose beads. The use of high concentrations of salts usually has some effects on enzyme stability, but the intensity and nature of these effects depends on the inactivation pH, nature and concentration of the salt, enzyme and immobilization protocol. The same salt can be a stabilizing or a destabilizing agent for a specific enzyme depending on its concentration, inactivation pH and immobilization protocol. Using lipases, (NH4)2SO4 generally permits the highest stabilities (although this is not a universal rule), but using the other enzymes this salt is in many instances a destabilizing agent. At pH 9.0, it is more likely to find a salt destabilizing effect than at pH 7.0. Results confirm the difficulty of foreseeing the effect of high concentrations of salts in a specific immobilized enzyme.

Specialty: Arresting an elusive ‘right’ in European extradition law

Specialty (a near-universal rule of extradition law whereby a person extradited cannot be prosecuted or punished for matters other than those for which they were extradited) is viewed traditionally as a tool to protect the sovereignty of the extraditing state, rather than as an individual right. A review of international material shows a dispute as to the existence of a rule or principle of specialty in customary international law and emphasises themes such as enforceability and standing of individuals to plead violations. Against that backdrop, the European situation is characterised by the presence of broad specialty rules which are not always implemented in legislation by requesting states, leading to refusal of extradition in some cases. Arguably, combinations of the EU law duty of conforming interpretation and European human rights law principles may offer tools to overcome such situations, approaching protection of specialty ‘rights’ whatever the original doctrinal rationale. If they do not, and international cooperation is further undermined by ineffective specialty protection, EU legislation or the development of soft law standards may be a useful way forward.

Mõningad märkused nelja ilmakaare kuninga ja jumal-kuninga kontseptsiooni kohta Sumeris ja Akkadis 3. at eKr

This article is dedicated to the issues related to the King of the Four Corners and the God-King in ancient Sumer and Akkad in the 3rd millennium BCE. The author shows that the title King of the Four Corners has always deified the ruler, but the ruler who used the title King of the Universe never claimed divinity. What conclusions can we draw? Except in two cases – the case of Erri-dupizir and the case of Utu-ḫeĝal – all kings who used the title king of the four corners were deified. Erri-dupizir was a foreigner, more a warlord or tribal chief of the Gutians than a king, but he tried to legitimate his power by using Akkadian-Sumerian formulas, among them royal titles. Utu-ḫeĝal freed Sumer from the Gutians’ yoke and re-introduced old Sumero-Akkadian ideological elements, among them the king of the four corners, because he wanted to be as powerful and strong as the Akkadian king Narām-Su’en, who was an example for Utu-ḫeĝal. We do not have any proof regarding the deification of Utu-ḫeĝal, as he ruled only 6–7 years, and we have only a few texts from the time of his reign. More interesting is the fact that none of the Sumerian or Akkadian kings who used the title king of the universe in the 3rd millennium and even in the early 2nd millennium BCE (Isin-Larsa period) were deified (at least we do not have a firm proof). How to explain this phenomenon? Firstly, I think the title king of the four corners had a slightly different meaning than king of the universe; however, both are universalistic titles. The title king of the four corners was probably seen as a wider and more important universalistic title in the sense not only of universal rule, but also of ruling the divine universe and divine spheres (heaven, sun, stars, etc.). It seems that it included some kind of divine aspect, while at least the Sumerian version of the title lugal an-ubda-limmuba means “king of the heaven’s four corners”. The title king of the four corners was related to the universe order, to the sun and the cosmos, and to cosmic divine powers, and they were connected to the universal order. We can see that sometimes the title king of the four corners was used to refer to gods in Ancient Mesopotamia – for example in the case of the god Tišpak in Ešnunna – but never king of the universe. Secondly, early dynastic rulers (e.g. Lagash or Uruk), who never used universalistic titles for themselves, addressed universalistic expressions and epithets to the main gods – e.g., Enlil, Ningirsu, etc. For example, Lugal-kiğine-dudu of Uruk claimed: “Enlil, king of all lands, for Lugal-kiğine-dudu – when the god Enlil truly summoned him, and (Enlil) combined (both) lordship and kingship for him”. Thirdly, ruling over all the lands from east to west or over the corners of the universe – these epithets may be used for gods. LUGAL KIŠ (later Akkadian šar kiššati(m)) in its early original meaning was seen only as “ruler over Kiš (or ruler over (the northern part of) Sumer)”; it was an important though more regional and geographic title. Fourthly, only much later did it acquire the meaning king of the universe but I am not sure about that meaning at all. In that case, king of the four corners had a different meaning; the title designated not only ruling over the world but it probably included some kind of divine aspect as well (Michalowski 2010). In that case the title šar kibrāt arbaˀi(m) – king of the four corners could be seen as more universal than LUGAL KIŠ (šar kiššati(m)). There still remain several questions which need to be solved: * Was LUGAL KIŠ in its Akkadian form šar kiššati(m) a universalistic title at all? * Or was LUGAL KIŠ a hegemonic title showing certain hegemonic rule or lordship over (all) Sumer (and Akkad?) but not including the whole world (here: Mesopotamia)? * Could it be for this reason that the king who used the title king of the four corners had to be deified but the king who was LUGAL KIŠ had not?

Models of Constitution Making with Reference to Nepal

Constitution is commonly called as the foundation, framework, guideline, roadmap, charter, established rule or legal order of government. It is the supreme and fundamental law of the state because constitution gives legitimacy or validity to all laws and no laws surviving against the constitution. Law is valid only if it is in conformity with the constitution. Constitution being the basic and organic law of land the process of its making is quite important. Constitution making is the act of creating and reforming the body of fundamental principles that govern a state. Constitution making is, therefore, a critical entry point for shaping the future of a country, the exercise of power and the social compact among citizens and between citizens and their state. There is no universal rule, formula, exact method or model for making a constitution. There are several models used in constitution making such as commission model, expert model, constituent assembly model, referendum model, draft committee model, gift model, colonial model, adherence model, peace negotiation model, national conference model, etc. The models of constitution making is selected according to geographical, social, cultural, religious, economic, historical, political and legal system of a concerned country. Hence, in this article the author clearly presents the clear perspectives of constitution, constitution making and the popular models and the procedures used in making constitution with reference to Nepalese experiences and instances.

Private Uniform Law and Global Legal Pluralism

Global legal pluralism comes in many forms and carries various implications. This chapter traces the phenomena of legal pluralism in the field of commercial law. It is commonly held that legal certainty is of paramount importance to merchants. Therefore, efforts to harmonize commercial law on the international level are pertinent, albeit with limited success. As states proved unwilling or unable to create uniform commercial law, various private initiatives were established to achieve this end, the most prominent examples being the International Commercial Terms (Incoterms) and the Uniform Customs and Practice for Documentary Credits (UCP), both promulgated by the International Chamber of Commerce. From the perspective of global legal pluralism, such privately created uniform commercial law is an instance of legal pluralism. Interestingly, in this case it is not state law as the universal rule, which encounters conflicting normative claims of a substate social field, but it is a privately created normative regime that claims universal authority over the fragmented domestic commercial law regimes. According to conventional legal theory, such claim is simply ridiculous and it seems to be impossible for private uniform law to operate successfully. However, an analysis of English and German case law reveals that the Incoterms and the UCP in fact are effectively operating as uniform law and thus as a privately created functional equivalent to international instruments such as the Convention on the International Sale of Goods. This chapter, therefore, argues that beyond theoretical discussions in textbooks, judges do practice what global legal pluralism suggests.

Forces experienced by instrumented animals depend on lifestyle

Animal-attached devices have transformed our understanding of vertebrate ecology. However, to be acceptable, researchers must minimize tag-related harm. The long-standing recommendation that tag masses should not exceed 3% of the animal’s body mass ignores tag forces generated by movement. We used collar-attached accelerometers on four free-ranging carnivores, spanning two orders of magnitude in mass, to reveal that during movement, forces exerted by ‘3%’ tags were generally equivalent to 4-19% of the animals’ masses, with a record of 54% in a hunting cheetah. Controlled studies on domestic dogs revealed how the tag forces are dictated by animal gait and speed but appear largely invariant of body mass. This fundamentally changes how acceptable tag mass limits should be determined, requiring cognizance of animal athleticism.One Sentence SummaryThere can be no universal rule for collar-tag masses as a percentage of carrier mass since tag forces depend on lifestyle.