bluuebunny/crossref_metadata_2025 huggingface dataset:
HCCH
Authors: Ribeiro-Bidaoui João
Published: May 2021

This chapter focuses on the Hague Conference on Private International Law (HCCH), a global intergovernmental organization which develops and services multilateral legal instruments, in response to global needs. The HCCH Principles affirm party autonomy as a basis for the choice of law in international contracts and strengthen legal certainty and predictability in cross-border commercial transactions. They are important to easing reform and harmonization initiatives concerning the rules applicable to international trade, and they operate as both a model choice of law regime and as a guide to ‘best practices’ in establishing and refining such a regime. The chapter considers the use of the HCCH Principles to date and foreshadows their potential uses in the future. It reviews the envisaged use of the Principles by legislators at national and international levels, international organizations, courts, arbitral tribunals, the commercial parties, and their legal counsel. The chapter then outlines the parties to whom the Principles may be promoted in a manner consistent with the Preamble and identifies specific means for promotion.
UNCITRAL
Authors: Castellani Luca , Emery Cyril
Published: May 2021

This chapter evaluates the relationship between the United Nations Commission on International Trade Law (UNCITRAL) and the Hague Principles. The UNCITRAL texts, starting with the early drafts of the United Nations Convention on Contracts for the International Sale of Goods (CISG), have provided solid ground in support of freedom of contract. In providing a uniform model applicable to multiple jurisdictions, the CISG ensures a high level of safeguard of parties’ wills. In particular, the CISG promotes the well-established principle of party autonomy by virtue of its Article 6, which allows parties to the contract to opt out entirely of its provisions and hence to choose another law more appropriate to their needs. Given UNCITRAL’s desire to further facilitate use of the CISG by traders and in light of its focus on freedom of contract and party autonomy, it is not surprising that the UNCITRAL Secretariat took a particular interest in the development by the Hague Conference on Private International Law of the Principles on Choice of Law in International Commercial Contracts (2015) and the related Commentary. The chapter then looks at UNCITRAL’s endorsement of the Hague Principles.
African Principles of Commercial Private International Law
Authors: Neels Jan L , Fredericks Eesa A
Published: May 2021

This chapter addresses the relationship between the African Principles of Commercial Private International Law and the Hague Principles. The envisaged African Principles are essential in the development of an African free-trade area and common market. They are intended to form a set of model laws for use by the African Union or its Member States, which are provisionally called the African Principles on the Law Applicable to International Contracts of Sale; the African Principles on the Law Applicable to International Commercial Contracts; the African Principles on the Law Applicable to Non-contractual Obligations; and the African Principles on Jurisdiction in International Civil and Commercial Cases. The Hague Principles will be the most important model for the choice of law sections of the African Principles on the Law Applicable to International Contracts of Sale and the African Principles on the Law Applicable to International Commercial Contracts. The Hague Principles, in the Preamble, indeed foresee the instrument being used as a model for regional instruments. The chapter then provides a few examples of the intended use of the Hague Principles in the African Principles, highlighting the added value of the Hague Principles as compared to the provisions in other regional, supranational, and international instruments.
Angola and Mozambique
Authors: Dias Rui , Nordmeier Carl Friedrich
Published: May 2021

This chapter explores Angolan and Mozambican perspectives on the Hague Principles. The rules of Angolan and Mozambican civil law, and with them private international law, currently in force correspond to the Portuguese rules as they stood in 1975. As to private international law, the 1966 Portuguese Civil Code (hereafter CC) contains a codification of this field of the law in Articles 15 to 65. Meanwhile, rules on international civil procedure are to be found in the Angolan and the Mozambican Civil Procedure Codes. They concern, inter alia, international jurisdiction and the enforcement of foreign judgments. Party autonomy is recognized as the principal connecting factor for contractual relationships (Art 41(1) CC). Nevertheless, the choice of law is not unlimited: it is necessary that either some of the elements of the contract having relevance in private international law are connected with the law chosen, or that the choice of the applicable law corresponds to a serious interest. It is clear from this backdrop that a set of rules, such as the Hague Principles, which present themselves as an embodiment of current best practices is well placed to help interpret, supplement, or develop the choice of law rules of the 1966 Civil Code.
Ethiopia
Authors: Gebremeskel Fekadu Petros
Published: May 2021

This chapter reflects on Ethiopian perspectives on the Hague Principles. Ethiopia does not have a codified law regulating matters of private international law, nor is there detailed case law from which one could derive key principles of the subject. While the shortage of private international law in Ethiopia is evident, the problem is most severe in the area of applicable law. In relation to party autonomy in choice of law, the Federal Supreme Court’s Cassation Division has handed down some interesting decisions, and these indeed have the force of law in Ethiopia. Nevertheless, the approach of the Ethiopian courts in respect of party autonomy is not very developed and clear, including in the field of international commercial contracts. While it would be prudent for Ethiopian courts to refer to the Hague Principles as persuasive authority, this requires awareness of the existence of the Hague Principles. In the long term, the Hague Principles will surely find their way into Ethiopian law.
Asian Principles of Private International Law
Authors: Takasugi Naoshi , Elbalti Béligh
Published: May 2021

This chapter looks at the relationship between the Asian Principles of Private International Law (APPIL) and the Hague Principles. The APPIL are intended to be a non-binding instrument which includes a comprehensive set of principles on private international law (PIL) generally recognized among the different Asian jurisdictions. The main purpose of the APPIL is to provide guidance to possible future harmonization of PIL rules and principles in Asia. Compared to the Hague Principles which are limited only to the issue of choice law in international contracts based on the express or tacit will of the parties, the APPIL have much broader scope, including choice of law, international jurisdiction, the recognition and enforcement of foreign judgments, and judicial support to international arbitration. The chapter then outlines the history and the driving force behind the APPIL.
Bahrain
Authors: Elbalti Béligh , Shaaban Hosam Osama
Published: May 2021

This chapter assesses Bahraini perspectives on the Hague Principles. In Bahrain, private international law rules are mainly found in domestic legislation. The main legislative text in this regard is the Act No 6/2015 on Conflict of Law in Civil and Commercial Matters involving a Foreign Element (the 2015 Act). The Act includes a number of rules of general application, among which is Article 4 on party autonomy in addition to some other rules relating to choice of law in contractual matters in general (Article 17) or applicable to special types of contracts and other juristic acts. It can be safely said that nothing in principle prevents the Bahraini courts from referring to the Hague Principles as a persuasive authority nor from using its solutions in the interpretation or the development of the applicable rules and principles of private international law in Bahrain. This is particularly true knowing that many of the solutions adopted by the 2015 Act are particularly consistent with the Hague Principles’ solutions.
China (Mainland)
Authors: He Qisheng
Published: May 2021

This chapter addresses Chinese perspectives on the Hague Principles. The modern legislation of private international law in China began with the establishment of choice of law in contracts. The first statute enacting private international law rules was the Foreign Economic Contract Law of 1985. Article 5 of the Law stipulated that the parties to a contract may choose the law applicable to the contract dispute. Since the promulgation of the Foreign Economic Contract Law, party autonomy and the closest connection doctrine have been two major approaches in determining the law applicable to a contract dispute. In 2010, the National People’s Congress of China promulgated a new private international law: the Law of the People’s Republic of China (PRC) on Application of Law for Foreign-Related Civil Relationships. The chapter then compares the current position of private international law of contract in Mainland China with the Hague Principles.
Dubai International Financial Centre
Authors: Elrifai Silke Noa
Published: May 2021

This chapter describes the Dubai International Financial Centre (DIFC) perspectives on the Hague Principles. Whereas the DIFC is bound by international treaties ratified by the United Arab Emirates (UAE) on a federal level, the DIFC’s domestic sources of private international law are laid down in several statutory enactments and, as a common law jurisdiction, also case law. The most important rules on choice of law in international contracts are codified in the DIFC Law No 10 of 2005 (the DIFC Law Application Law), which govern the law applicable to contractual obligations. It sets out clearly and succinctly the most important applicable law rules, which respect the parties’ autonomy to choose the applicable law. Although Article 30(1) of the DIFC Court Law clearly instructs the DIFC Courts what law they must apply, Article 30(2) authorizes the DIFC Courts to ‘consider decisions made in other jurisdictions for the purpose of making its decision’. Accordingly, so far as the Hague Principles have been referenced in decisions in other jurisdictions, the Court may also refer to them.
Indonesia
Authors: Lumbantobing John , Hardjowahono Bayu Seto
Published: May 2021

This chapter highlights Indonesian perspectives on the Hague Principles. Generally speaking, private international law (PIL) in Indonesia is not an area of law where statutory rules have developed in a comprehensive and systematic manner. Rules on many aspects of private international law, including the freedom of choice of law, remain very rudimentary and do not address sufficiently complicated legal questions surrounding modern commercial transactions. The chapter then analyses Indonesian PIL doctrines and court decisions on party autonomy in contracts. It is uncertain whether and how far the Hague Principles can be accepted as a persuasive authority in the interpretation, supplementation, and/or development of the applicable rules and principles of private international law before the Indonesian courts. In principle, there is no restriction for the courts to refer to international instruments as sources of inspiration for interpreting or filling gaps of existing rules. However, Indonesian courts are infamously insular and are not receptive to foreign materials, particularly ‘soft law’ resources which are not part of national laws of a sovereign state.
Iran
Authors: Yassari Nadjma
Published: May 2021

This chapter presents Iranian perspectives on the Hague Principles. Generally, private international law is not very developed in Iran, neither in theory nor in practice. This is for diverse reasons: the history and the legacy of the capitulations systems, according to which foreign citizen and entities were exempted from Iranian jurisdiction, is still vividly felt, as is the fear of potential foreign domination. This has nurtured a general suspicion towards the application of foreign law as a gateway for political intervention of foreign powers. Following the revolution of 1979, the political situation and the instability and insecurity of foreign investments have been major impediments to the spread of international commerce between Iran and the rest of the world, diminishing the need to establish efficient private international law tools. This factual situation is mirrored by a poor engagement with international contract law in scholarly writings, which often remain hypothetical and abstract due to the lack of case law. Nowhere in the literature is any reference made to the Hague Principles. Only in the field of international arbitration has there been some movement: in 1997, the Law on International Commercial Arbitration (LICA) was enacted, a code that relies greatly on the United Nations Commission on International Trade Law (UNCITRAL) Model Law.
Vietnam
Authors: Doan Duc Luong , Nguyen Thi Hong Trinh
Published: May 2021

This chapter reflects on Vietnamese perspectives on the Hague Principles. In Vietnam, the sources of private international law in respect of international commercial contracts includes the bilateral judicial assistance treaties between Vietnam and related countries, among which eight treaties contain conflict rules for the content of the contract and eleven treaties contain conflict rules for the parties’ capacity in entering the contract. As for national legislation, which is established in Vietnam as the major source of private international law, the Vietnamese Civil Procedure Code (VCPC) 2015 provides for the procedures regarding civil disputes with foreign elements (Part VIII) and the recognition and enforcement of the decisions of foreign courts and the decisions of foreign arbitrators in Vietnam (Part VII). At the same time, the Vietnamese Civil Code (VCC) 2015 contains Part V which regulates the law applicable to civil relations involving foreign elements. As far as the Hague Principles are concerned, this is being addressed in the drafting stage of Part V of the VCC 2015 (on conflict rules). The influence of the Hague Principles on the Vietnamese legislature may be stronger when they are more well known in the future.
Russia
Authors: Karayanidi Milana
Published: May 2021

This chapter addresses Russian perspectives on the Hague Principles. It analyses choice of law rules applicable to international commercial contracts in Russia. These rules apply to contracts that have a foreign element from a Russian standpoint and they are codified in a variety of sources, including the Civil Code, the Code of Civil Procedure, the Code of Arbitrazh Procedure, the Federal Law on Fundamentals of State Regulation of International Trade, and numerous other statutes on specific issues. International treaties to which Russia is a signatory State also regulate private international law issues, and the provisions of such treaties prevail over Russian domestic law in case of a conflict. Generally, courts in Russia are also not forbidden to refer to other international instruments when such sources are directly incorporated into an agreement between private parties. Russian courts will also enforce terms of customary business practices, where parties to international commercial contract agree to use them. Although there is no ongoing reform relating to the law applicable to cross-border contracts in Russia, the comparison of Russian private international law rules and the Hague Principles shows that the Hague Principles may play a role in improving relevant rules in Russia.
Ukraine
Authors: Vorobey Dmytro
Published: May 2021

This chapter studies Ukrainian perspectives on the Hague Principles. Ukrainian private international law act, or formally the ‘Law of Ukraine “On Private International Law” ’ (PIL), was adopted on June 23, 2005. As per the Preamble to the PIL, it applies to ‘private [legal] relationships which are connected to one or more legal orders other than the Ukrainian legal order’. According to Article 2 of the PIL, it applies to matters of choice of law, procedural standing of foreign citizens, stateless persons and foreign legal entities, jurisdiction of Ukrainian courts in cases involving foreign parties, execution of letters rogatory, and recognition and enforcement of foreign court judgements in Ukraine. The Ukrainian private international law and specifically the PIL were influenced by the 1980 Rome Convention on the Law Applicable to Contractual Obligations. Although, considering the relative novelty of the Hague Principles, the authority of the courts to refer to the Hague Principles has not been addressed by the higher Ukrainian courts, the courts have frequently referred to the international codifications of contract law such as the UNIDROIT Principles of International Commercial Contracts.
United Kingdom
Authors: Dickinson Andrew
Published: May 2021

This chapter highlights United Kingdom perspectives on the Hague Principles. On 31 January 2020, the UK ceased to be a member of the EU. Under the terms of the Withdrawal Agreement concluded between the UK and the EU, the UK will apply the Rome I Regulation to contracts concluded before the end of the transition period. The UK has taken a policy decision to continue to apply the Rome I Regulation to determine the law applicable to contractual obligations with respect to contracts concluded after the end of the transition period, and has adopted legislation to achieve that end. Following the ‘IP completion day’, UK courts will have no power to refer questions of law to the EU’s Court of Justice (CJEU) and will not be bound by decisions of the CJEU made after that date, although they ‘may have regard to’ such decisions. In the absence of a significant existing body of CJEU case law concerning the Rome I Regulation and its predecessor, the 1980 Rome Convention on the law applicable to contractual obligations, UK courts will seek guidance from the existing body of local case law, which will continue to bind them in accordance with common law rules of precedent. In this enterprise, the Hague Principles, as an instrument adopted by the members of a well-respected international legal organization of which the UK is a long-standing member, may prove to be an influential tool, especially when addressing novel questions.
Argentina
Authors: All Paula María
Published: May 2021

This chapter discusses Argentine perspectives on the Hague Principles. As regards conventional private international Law, Argentina has ratified the Montevideo Treaties on International Civil Law of 1889 and 1940, which regulate the law applicable to international contracts in Articles 32–39 and 36–42, respectively. Concerning domestic private international Law, its provisions are envisaged in the Argentine Civil and Commercial Code and special statutes. On 7 October 2014, Argentina enacted a new Civil and Commercial Code (CCyCN, for its Spanish acronym), which came into force on 1 August 2015. The regulatory sources consulted for the drafting of the New Code did not include the Hague Principles. Nevertheless, were the CCyCN to be amended in the future, nothing would prevent the Hague Principles from being considered at the time of modifying rules on the law applicable to international contracts. Within the judicial framework, Argentine courts may use the Hague Principles in order to interpret or supplement rules of law on the law applicable to international contracts.
Bolivia
Authors: Schütt José Manuel Canelas
Published: May 2021

This chapter examines Bolivian perspectives on the Hague Principles. Bolivia has few legal provisions and little meaningful legal precedent referring to international commercial contracts and choice of law. Nevertheless, Bolivia’s legal system recognizes the importance of party autonomy, custom, usage, equity, and even culture in contract law. In that sense, the Hague Principles may be useful in a variety of ways, such as supplementing or re-interpreting national laws, as guidance for legal reform, or as incorporated by reference into a contract. The existing legal vacuums in Bolivian law may at times offer even broader opportunities for their use than in other jurisdictions where the law is more developed. The Hague Principles could be applied by courts and arbitral tribunals as a subsidiary source of law, either in cases where there is no specific rule applicable to the matter at hand or in cases where the Hague Principles would be helpful to interpret the applicable conflict rule. The application of the Hague Principles cannot contradict Bolivia’s mandatory rules or public policy. For an effective use of the Hague Principles, it should be noted how these are in line with constitutional principles, particularly party autonomy.
Chile
Authors: Gallegos-Zúñiga Jaime
Published: May 2021

This chapter focuses on Chilean perspectives on the Hague Principles. Due to the scarce and mostly unilateral provisions on private international law contained in Chilean legislation, there remain large gaps in the system. Chilean judges must therefore deduce relevant principles, and the result is often unclear solutions. Nevertheless, the recognition of party autonomy is increasingly gaining ground in academic literature and court judgments. On 2 October 2017, the Ministry of Justice and Human Rights, the Faculty of Law at the University of Chile, and the Chilean Association of Private International Law signed an agreement to compose a Draft Act of Private International Law. This work is being developed by a commission of specialists and originally revolved around the draft Model Act of the Organization for the Harmonization of Business Law in the Caribbean (OHADAC) of 2014. Many of the ideas contained in the Hague Principles have been acknowledged and included in the draft, which is expected to be submitted to the National Congress. Given the lack of rules that specify the scope of party autonomy, the provisions contained in this instrument would be a welcome contribution to the Chilean legal system.
Panama
Authors: Montenegro Carlos Alberto Arrue
Published: May 2021

This chapter studies Panamanian perspectives on the Hague Principles. In relation to obligations and contracts, the Panamanian Civil Code reproduces Book IV, ‘Of Obligations and Contracts’, of the Spanish Civil Code of 1889, but contains a number of important differences in other sections. In terms of sources of law, statutes occupy the most prominent position among sources of law. Consequently, neither interpretations given by Panamanian courts, nor decisions on previous cases, are binding for courts that must then decide on similar cases, even when the same provisions apply. Nevertheless, judicial decisions may, and in fact usually do, serve as an illustration on the correct application or interpretation of a legal rule. It is in this limited context that the Panamanian courts may refer to the Hague Principles and other principles of private international law and/or international contracts. The latter will not have an automatic or binding effect, but they may provide legal authority upon which the court may depend to properly interpret similar provisions of Panamanian private international law, or otherwise develop and complete legal gaps in Panamanian private international law.
Uruguay
Authors: de Aguirre Cecilia Fresnedo
Published: May 2021

This chapter reflects on Uruguayan perspectives on the Hague Principles. In Uruguay, international commercial contracts are regulated by the following conventions: the Montevideo Treaty on International Civil Law of 1889; the Montevideo Treaty on International Civil Law of 1940; the Additional Protocol to the Montevideo Treaty on International Civil Law of 1940; and the Buenos Aires Protocol on International Jurisdiction in Contractual Matters. They are also regulated under the domestic private international law rules contained within the Appendix of the Civil Code of Uruguay. The Appendix of the Civil Code, including rules regulating contract, is under revision; a Draft General Act on Private International Law is in Parliament under consideration. It seems unlikely that the Hague Principles will play any role regarding this Draft Act at present; however, the draft has yet to be approved mainly due to disagreement on the role of party autonomy. If the Draft Act is approved and entered into force, the Hague Principles may become useful in Uruguayan law.
United States of America
Authors: Symeonides Symeon C , Cohen Neil B
Published: May 2021

This chapter focuses on American perspectives on the Hague Principles. At the state level, Louisiana and Oregon have enacted comprehensive choice of law codifications, which strongly endorse party autonomy. Many other states have enacted statutory provisions that affect party autonomy. At one end of the spectrum, there are provisions that prohibit or restrict outbound choice of law clauses in certain contracts that have enumerated contacts with the enacting state. At the other end of the spectrum, there are statutes designed to ensure enforcement of inbound choice of law clauses in certain commercial contracts with high-dollar value, even in the absence of any connection with the enacting state. Despite the multiplicity of state statutes, many of which pre-empt a judicial choice of law or obviate the need for it, the bulk of American conflicts law for matters other than those governed by the Uniform Commercial Code is found in judicial decisions. In keeping with the common law tradition, American courts play an active role in the development of the law, both in general and regarding party autonomy in particular. One hopes that American courts will take into account the Hague Principles, if only for answering those questions, as few as they may be, whose answer is unclear under American law.
Respiratory Viral Pathogens Among U.S. Military Personnel at a Medical Treatment Facility in Hawaii From 2014 to 2019
Authors: Montgomery Agnes S , Lustik Michael B , Reichert-Scrivner Susan A , Woodbury Ronald L , Jones Milissa U , Horseman Timothy S
Published: May 2021

Introduction

Acute respiratory diseases account for a substantial number of outpatient visits and hospitalizations among U.S. military personnel, significantly affecting mission readiness and military operations. We conducted a retrospective analysis of respiratory viral pathogen (RVP) samples collected from U.S. military personnel stationed in Hawaii and tested at Tripler Army Medical Center from January 2014 to May 2019 in order to describe the etiology, distribution, and seasonality of RVP exposure in a military population.

Materials and Methods

Samples were analyzed by viral culture or multiplex PCR. Distribution of respiratory viruses over time was analyzed as well as subject demographic and encounter data. Presenting signs and symptoms were evaluated with each RVP.

Results

A total of 2,576 military personnel were tested, of which 726 (28.2%) were positive for one or more RVP. Among positive tests, the three most common viral pathogens detected were influenza A (43.0%), rhinovirus (24.5%), and parainfluenza (7.6%). Symptoms were generally mild and most frequently included cough, fever, and body aches.

Conclusion

Our study evaluated respiratory virus prevalence, seasonality, and association with clinical symptoms for military personnel in an urban tropical setting in Oahu, HI, over a 5-year period. We show that viral prevalence and seasonality in Hawaii are distinct from those of the CONUS. Results contribute to the broader understanding of seasonality, clinical manifestation, and demographics of RVP among active duty military personnel stationed in Hawaii.
In vitro and in vivo interaction of caspofungin with isavuconazole against Candida auris planktonic cells and biofilms
Authors: Nagy Fruzsina , Tóth Zoltán , Nyikos Fanni , Forgács Lajos , Jakab Ágnes , Borman Andrew M , Majoros László , Kovács Renátó
Published: May 2021

The in vitro and in vivo efficacy of caspofungin was determined in combination with isavuconazole against Candida auris. Drug–drug interactions were assessed utilizing the fractional inhibitory concentration indices (FICIs), the Bliss independence model and an immunocompromised mouse model. Median planktonic minimum inhibitory concentrations (pMICs) of 23 C. auris isolates were between 0.5 and 2 mg/l and between 0.015 and 4 mg/l for caspofungin and isavuconazole, respectively. Median pMICs for caspofungin and isavuconazole in combination showed 2–128-fold and 2–256-fold decreases, respectively. Caspofungin and isavuconazole showed synergism in 14 out of 23 planktonic isolates (FICI range 0.03–0.5; Bliss cumulative synergy volume range 0–4.83). Median sessile MICs (sMIC) of 14 biofilm-forming isolates were between 32 and >32 mg/l and between 0.5 and >2 mg/l for caspofungin and isavuconazole, respectively. Median sMICs for caspofungin and isavuconazole in combination showed 0–128-fold and 0-512-fold decreases, respectively. Caspofungin and isavuconazole showed synergistic interaction in 12 out of 14 sessile isolates (FICI range 0.023–0.5; Bliss cumulative synergy volume range 0.13–234.32). In line with the in vitro findings, synergistic interactions were confirmed by in vivo experiments. The fungal kidney burden decreases were more than three log volumes in mice treated with combination of 1 mg/kg caspofungin and 20 mg/kg isavuconazole daily; this difference was statistically significant compared with control mice (P < 0.001). Despite the favorable effect of isavuconazole in combination with caspofungin, further studies are needed to confirm the therapeutic advantage of this combination when treating an infection caused by C. auris.
Dynamically produced moving groups in interacting simulations
Authors: Craig Peter , Chakrabarti Sukanya , Newberg Heidi , Quillen Alice
Published: May 2021

We show that smoothed particle hydrodynamics (SPH) simulations of dwarf galaxies interacting with a Milky Way-like disc produce moving groups in the simulated stellar disc. We analyse three different simulations: one that includes dwarf galaxies that mimic the Large Magellanic Cloud, Small Magellanic Cloud, and the Sagittarius dwarf spheroidal; another with a dwarf galaxy that orbits nearly in the plane of the Milky Way disc; and a null case that does not include a dwarf galaxy interaction. We present a new algorithm to find large moving groups in the VR, Vϕ plane in an automated fashion that allows us to compare velocity substructure in different simulations, at different locations, and at different times. We find that there are significantly more moving groups formed in the interacting simulations than in the isolated simulation. A number of dwarf galaxies are known to orbit the Milky Way, with at least one known to have had a close pericentre approach. Our analysis of simulations here indicates that dwarf galaxies like those orbiting our Galaxy produce large moving groups in the disc. Our analysis also suggests that some of the moving groups in the Milky Way may have formed due to dynamical interactions with perturbing dwarf satellites. The groups identified in the simulations by our algorithm have similar properties to those found in the Milky Way, including similar fractions of the total stellar population included in the groups, as well as similar average velocities and velocity dispersions.
Calibration of the Advanced Spectral Leakage scheme for neutron star merger simulations, and extension to smoothed-particle hydrodynamics
Authors: Gizzi D , Lundman C , O’Connor E , Rosswog S , Perego A
Published: May 2021

We calibrate a neutrino transport approximation, called Advanced Spectral Leakage (ASL), with the purpose of modelling neutrino-driven winds in neutron star mergers. Based on a number of snapshots, we gauge the ASL parameters by comparing against both the two-moment (M1) scheme implemented in the flash code and the Monte Carlo neutrino code sedonu. The ASL scheme contains three parameters, the least robust of which results to be a blocking parameter for electron neutrinos and antineutrinos. The parameter steering the angular distribution of neutrino heating is recalibrated compared to the earlier work. We also present a new, fast and mesh-free algorithm for calculating spectral optical depths, which, when using smoothed-particle hydrodynamics (SPH), makes the neutrino transport completely particle-based. We estimate a speed-up of a factor of ≳100 in the optical depth calculation when comparing to a grid-based approach. In the suggested calibration we recover luminosities and mean energies within $25{{\ \rm per\ cent}}$. A comparison of the rates of change of internal energy and electron fraction in the neutrino-driven wind suggests comparable accuracies of ASL and M1, but a higher computational efficiency of the ASL scheme. We estimate that the ratio between the CPU hours spent on the ASL neutrino scheme and those spent on the hydrodynamics is ≲0.8 per time-step when considering the SPH code magma2 as source code for the Lagrangian hydrodynamics, to be compared with a factor of 10 from the M1 in flash.
MUSE-ALMA haloes VI: coupling atomic, ionized, and molecular gas kinematics of galaxies
Authors: Szakacs Roland , Péroux Céline , Zwaan Martin , Hamanowicz Aleksandra , Klitsch Anne , Fresco Alejandra Y , Augustin Ramona , Biggs Andrew , Kulkarni Varsha , Rahmani Hadi
Published: May 2021

We present results of MUSE-ALMA haloes, an ongoing study of the circumgalactic medium (CGM) of galaxies (z ≤ 1.4). Using multiphase observations we probe the neutral, ionized, and molecular gas in a subsample containing six absorbers and nine associated galaxies in the redshift range z ∼ 0.3–0.75. Here, we give an in-depth analysis of the newly CO-detected galaxy Q2131−G1 (z = 0.42974), while providing stringent mass and depletion time limits for the non-detected galaxies. Q2131−G1 is associated with an absorber with column densities of log(NH i/cm−2) ∼ 19.5 and $\textrm {log}(N_{\textrm {H}_2}/\textrm {cm}^{-2}) \sim 16.5$, and has a star formation rate of SFR = 2.00 ± 0.20 M⊙yr−1, a dark matter fraction of fDM(r1/2) = 0.24–0.54, and a molecular gas mass of $M_\textrm {mol} = 3.52 ^{+3.95}_{-0.31} \times 10^9 \,\, \textrm {M}_{\odot }$ resulting in a depletion time of τdep < 4.15 Gyr. Kinematic modelling of both the CO (3–2) and [O iii] λ5008 emission lines of Q2131−G1 shows that the molecular and ionized gas phases are well aligned directionally and that the maximum rotation velocities closely match. These two gas phases within the disc are strongly coupled. The metallicity, kinematics, and orientation of the atomic and molecular gas traced by a two-component absorption feature are consistent with being part of the extended rotating disc with a well-separated additional component associated with infalling gas. Compared to emission-selected samples, we find that H i-selected galaxies have high molecular gas masses given their low star formation rate. We consequently derive high depletion times for these objects.
MusE GAs FLOw and Wind (MEGAFLOW) VI. A study of C iv and Mg ii absorbing gas surrounding [O ii] emitting galaxies
Authors: Schroetter Ilane , Bouché Nicolas F , Zabl Johannes , Rahmani Hadi , Wendt Martin , Muzahid Sowgat , Contini Thierry , Schaye Joop , Schmidt Kasper B , Wisotzki Lutz
Published: May 2021

Using the MEGAFLOW survey, which consists of a combination of MUSE and UVES observations of 22 quasar fields selected to contain strong Mg ii absorbers, we measure the covering fractions of C iv and Mg ii as a function of impact parameter b using a novel Bayesian logistic regression method on unbinned data, appropriate for small samples. We also analyse how the C iv and Mg ii covering fractions evolve with redshift. In the MUSE data, we found 215 $z = 1{-}1.5$ [O ii] emitters with fluxes ${\gt}10^{-17}$ erg s−1 cm−2 and within 250 kpc of quasar sight-lines. Over this redshift path $z = 1{-}1.5$, we have 19 (32) C iv (Mg ii) absorption systems with rest-frame equivalent width (REW) $W_r\gt $ 0.05 Å associated with at least one [O ii] emitter. The covering fractions of $z\approx 1.2$ C iv (Mg ii) absorbers with mean $W_r\approx$ 0.7 Å (1.0 Å), exceeds 50 per cent within 23$^{+62}_{-16}$ (46$^{+{18}}_{-13}$) kpc. Together with published studies, our results suggest that the covering fraction of C iv (Mg ii) becomes larger (smaller) with time, respectively. For absorption systems that have C iv but not Mg ii, we find in 73 per cent of the cases no [O ii] counterpart. This may indicate that C iv comes from the intergalactic medium (IGM), i.e. beyond 250 kpc, or that it is associated with lower mass or quiescent galaxies.
Probing the hadronic nature of the gamma-ray emission associated with Westerlund 2
Authors: Mestre Enrique , de Oña Wilhelmi Emma , Torres Diego F , Holch Tim Lukas , Schwanke Ullrich , Aharonian Felix , Parkinson Pablo Saz , Yang Ruizhi , Zanin Roberta
Published: May 2021

Star-forming regions have been proposed as potential Galactic cosmic ray accelerators for decades. Cosmic ray acceleration can be probed through observations of gamma-rays produced in inelastic proton–proton collisions at GeV and TeV energies. In this paper, we analyse more than 11 yr of Fermi–LAT data from the direction of Westerlund 2, one of the most massive and best-studied star-forming regions in our Galaxy. In particular, we investigate the characteristics of the bright pulsar PSR J1023–5746 that dominates the gamma-ray emission below a few GeV at the position of Westerlund 2 and the underlying extended source FGES J1023.3–5747. The analysis results in a clear identification of FGES J1023.3–5747 as the GeV counterpart of the TeV source HESS J1023-575, through its morphological and spectral properties. This identification provides new clues about the origin of the HESS J1023-575 gamma-ray emission, favouring a hadronic origin of the emission, powered by Westerlund 2, rather than a leptonic origin related to either the pulsar wind nebula associated with PSR J1023–5746 or the cluster itself. This result indirectly supports the hypothesis that star-forming regions can contribute to the cosmic ray sea observed in our Galaxy.
Estimating galaxy masses from kinematics of globular cluster systems: a new method based on deep learning
Authors: Kaur Rajvir , Bekki Kenji , Hassan Ghulam Mubashar , Datta Amitava
Published: May 2021

We present a new method by which the total masses of galaxies including dark matter can be estimated from the kinematics of their globular cluster systems (GCSs). In the proposed method, we apply the convolutional neural networks (CNNs) to the 2D maps of line-of-sight velocities (V) and velocity dispersions (σ) of GCSs predicted from numerical simulations of disc and elliptical galaxies. In this method, we first train the CNN using either only a larger number ($\sim 200\, 000$) of the synthesized 2D maps of σ (‘one-channel’) or those of both σ and V (‘two-channel’). Then, we use the CNN to predict the total masses of galaxies (i.e. test the CNN) for the totally unknown data set that is not used in training the CNN. The principal results show that overall accuracy for one-channel and two-channel data is 97.6 per cent and 97.8 per cent, respectively, which suggests that the new method is promising. The mean absolute errors (MAEs) for one-channel and two-channel data are 0.288 and 0.275, respectively, and the value of root mean square errors (RMSEs) are 0.539 and 0.51 for one-channel and two-channel, respectively. These smaller MAEs and RMSEs for two-channel data (i.e. better performance) suggest that the new method can properly consider the global rotation of GCSs in the mass estimation. We also applied our proposed method to real data collected from observations of NGC 3115 to compare the total mass predicted by our proposed method and other popular methods from the literature.
Hydrodynamic escape of an impact-generated reduced proto-atmosphere on Earth
Authors: Yoshida Tatsuya , Kuramoto Kiyoshi
Published: May 2021

Recent cosmochemical studies have shown that most of Earth’s building blocks were close to enstatite meteorites in isotopic compositions. This implies the formation of an impact-induced proto-atmosphere enriched in H2 and CH4 on accreting Earth. Such a reduced proto-atmosphere would have been largely lost by hydrodynamic escape, but its flux and time-scale for hydrogen depletion remain highly uncertain. Here we carry out 1D hydrodynamic escape simulations for such an H2–CH4 proto-atmosphere by incorporating expanded chemical networks and radiative cooling processes for estimation of the duration of the H2-rich surface environment on early Earth. In the escape outflow, CH4 is dissociated effectively by direct photolysis and chemical reactions with photochemically produced ion species. On the other hand, radiative cooling by photochemical products such as H$_{3}^{+}$, CH, and CH3 significantly suppresses atmospheric escape. Even though CH4 and their concentrations are small, the heating efficiency decreases to $\sim 5\, {{\ \rm per\ cent}}$ when CH4/H2 = 0.007 in the lower atmosphere and CH4 would suffer negligible escape when CH4/H2≳ 0.01. The time-scale for H2 escape consistent with the constraints of the isotopic compositions and the amount of C and N on the present Earth is possibly more than several hundred million years. Our results suggest that a long-lived hydrogen-rich reduced environment played important roles in climate warming and the generation of organic matters linked to the emergence of living organisms during the first several hundred million years of Earth.
The Rise of Digital Repression
Authors: Feldstein Steven
Published: May 2021

This book documents the rise of digital repression—how governments are deploying new technologies to counter dissent, maintain political control, and ensure regime survival. The emergence of varied digital technologies is bringing new dimensions to political repression. At its core, the expanding use of digital repression reflects a fairly simple motivation: states are seeking and finding new ways to control, manipulate, surveil, or disrupt real or perceived threats. This book investigates the goals, motivations, and drivers of digital repression. It presents case studies in Thailand, the Philippines, and Ethiopia, highlighting how governments pursue digital strategies based on a range of factors: ongoing levels of repression, leadership, state capacity, and technological development. But a basic political motive—how to preserve and sustain political incumbency—remains a principal explanation for their use. The international community is already seeing glimpses of what the frontiers of repression look like, such as in China, where authorities have brought together mass surveillance, online censorship, DNA collection, and artificial intelligence to enforce their rule in Xinjiang. Many of these trends are going global. This has major implications for democratic governments and civil society activists around the world. The book also presents innovative ideas and strategies for civil society and opposition movements to respond to the digital autocratic wave.
Global Patterns of Digital Repression
Authors: Feldstein Steven
Published: May 2021

This chapter presents quantitative data to explain the main arguments of the book. Specifically, it provides pooled, cross-national, time-series data to describe global patterns of digital repression, and it uses that data to develop and validate two composite indexes: a latent construct of digital repression and a latent construct of digital repression capacity. It discusses overall findings from the digital repression index—the relationship between regime type and digital repression, highest- and lowest-performing countries, as well as outliers. It also compares digital repression enactment to capacity, and investigates differences between autocracies and democracies. Finally, it analyzes individual components of digital repression—social media surveillance, online censorship, social manipulation and disinformation, Internet shutdowns, and arrests of online users for political content—and provide explanations for authoritarian and democratic use.
Thailand’s Strategy of Control
Authors: Feldstein Steven
Published: May 2021

This chapter presents a case study of how the Thai state deploys digital repression techniques to advance its political agenda. Thailand’s situation offers insights into how an autocratic state with a tradition of censorship and political suppression has adapted to a new digital environment. The Thai government has adeptly paired new information controls with old repressive methods, giving the state potent capabilities to control dissent. Thailand also demonstrates how digital repression is born from and develops out of internal drivers; external actors exercise limited influence in shaping the state’s digital strategies.
Transformation and Setbacks in Ethiopia
Authors: Feldstein Steven
Published: May 2021

This chapter focuses on political changes occurring in Ethiopia and their implications for digital technology. Since the early 2000s, Ethiopia has displayed a dismal track record when it comes to digital freedom. Internet shutdowns, rising disinformation, and traditions of online censorship and surveillance characterize Ethiopia’s digital environment. New prime minister Abiy Ahmed has ushered in important shifts, many of which are still in the early stages of implementation. Digital repression in 2020 looks very differently from prior years. This chapter discusses political change in Ethiopia and the impact of Abiy’s agenda. It describes the landscape of digital repression in the country, focusing on Internet shutdowns, rising levels of social disinformation and disinformation, as well as ongoing surveillance and censorship concerns. It then explains relevant factors that have shaped Ethiopia’s digital repression environment before turning to examine China’s influence in the country.
Enacting Political Friendship in Gezi
Authors: Çidam Çiğdem
Published: May 2021

This chapter deploys the alternative conceptual lens developed in the book, according to which democratic action is a theatrical experience created and sustained through the intermediating practices of political friendship, to analyze the Gezi protests of 2013. What emerges from this analysis is a richer account of events that moves beyond the limiting frameworks of success/failure and spontaneity/organization by bringing to light both the on-the-ground practices of political actors and the messiness and impurity of democratic politics even in the moment of its staging. Focusing on such intermediating practices as deliberation, judging, negotiation, artistic production, common use, and the organization of the mundane aspects of everyday life, the chapter demonstrates that those who took part in Gezi borrowed from past struggles, including May ’68, re-activated political habits, and, acting in unexpected ways, created new, if imperfect and fragile, forms of commonality among diverse figures, showing that another way of doing things is possible.