bluuebunny/crossref_metadata_2025 huggingface dataset:
βγ-systems interacting with sigma-models
Authors: Lindström Ulf , Roček Martin
Published: June 2020

Abstract

We find a geometric description of interacting βγ-systems as a null Kac-Moody quotient of a nonlinear sigma-model for systems with varying amounts of supersymmetry.
A universal polyphosphate kinase: PPK2c of Ralstonia eutropha accepts purine and pyrimidine nucleotides including uridine diphosphate
Authors: Hildenbrand Jennie C. , Teleki Attila , Jendrossek Dieter
Published: June 2020

Polyphosphosphate kinases (PPKs) catalyse the reversible transfer of the γ-phosphate group of a nucleoside-triphosphate to a growing chain of polyphosphate. Most known PPKs are specific for ATP, but some can also use GTP as a phosphate donor. In this study, we describe the properties of a PPK2-type PPK of the β-proteobacterium Ralstonia eutropha. The purified enzyme (PPK2c) is highly unspecific and accepts purine nucleotides as well as the pyridine nucleotides including UTP as substrates. The presence of a polyP primer is not necessary for activity. The corresponding nucleoside diphosphates and microscopically detectable polyphosphate granules were identified as reaction products. PPK2c also catalyses the formation of ATP, GTP, CTP, dTTP and UTP from the corresponding nucleoside diphosphates, if polyP is present as a phosphate donor. Remarkably, the nucleoside-tetraphosphates AT(4)P, GT(4)P, CT(4)P, dTT(4)P and UT(4)P were also detected in substantial amounts. The low nucleotide specificity of PPK2c predestines this enzyme in combination with polyP to become a powerful tool for the regeneration of ATP and other nucleotides in biotechnological applications. As an example, PPK2c and polyP were used to replace ATP and to fuel the hexokinase-catalysed phosphorylation of glucose with only catalytic amounts of ADP.

Key Points

• PPK2c of R. eutropha can be used for regeneration of any NTP or dNTP.

• PPK2c is highly unspecific and accepts all purine and pyrimidine nucleotides.

• PPK2c forms polyphosphate granules in vitro from any NTP.
Complete Willmore Legendrian surfaces in $${\mathbb {S}}^5$$ are minimal Legendrian surfaces
Authors: Luo Yong , Sun Linlin
Published: June 2020

In this paper, we continue to consider Willmore Legendrian surfaces and csL Willmore surfaces in $${\mathbb {S}}^5$$

S

5

, notions introduced by Luo (Calc Var Partial Differ Equ 56, Art. 86, 19, 2017. 10.1007/s00526-017-1183-z). We will prove that every complete Willmore Legendrian surface in $${\mathbb {S}}^5$$

S

5

is minimal and find nontrivial examples of csL Willmore surfaces in $${\mathbb {S}}^5$$

S

5

.
CXCL13 Is Involved in the Lipopolysaccharide-Induced Hyperpermeability of Umbilical Vein Endothelial Cells
Authors: Chen Wen , Wang Yi , Zhou Ting , Xu Yuansheng , Zhan Jianwei , Wu Jinhong
Published: June 2020

Abstract

Sepsis is a disease that is characterized by a severe systemic inflammatory response to microbial infection and lipopolysaccharide (LPS) and is a well-known inducer of sepsis, as well as endothelial cell hyperpermeability. In the present study, we confirm the elevation of CXC chemokine ligand 13 (CXCL13) in sepsis patients. We also show that LPS exposure increases the release of CXCL13, as well as the mRNA and protein expression of CXCL13 and its receptor, CXC chemokine receptor 5 (CXCR5) in human umbilical vein endothelial cells (HUVECs) in a dose- and time-dependent manner. We also examined the effects of CXCL13 knockdown on LPS-mediated endothelial hyperpermeability and tight junction (TJ) protein expression in HUVECs. Our results show that HUVECs exposed to LPS result in a significant decrease in transendothelial electrical resistance (TER) and TJ protein (Zonula occluden-1, occludin, and claudin-4) expression, and a notable increase in fluorescein isothiocyanate (FITC)-dextran flux and p38 phosphorylation, which was partially reversed by CXCL13 knockdown. Recombinant CXCL13 treatment had a similar effect as LPS exposure, which was attenuated by a p38 inhibitor, SB203580. Moreover, the CXCL13-neutralizing antibody significantly increased the survival rate of LPS-induced sepsis mice. Collectively, our results show that CXCL13 plays a key role in LPS-induced endothelium hyperpermeability via regulating p38 signaling and suggests that therapeutically targeting CXCL13 may be beneficial for the treatment of sepsis.
Treatment of adults with intracranial hemorrhage on apixaban or rivaroxaban with prothrombin complex concentrate products
Authors: Castillo Renee , Chan Alissa , Atallah Steven , Derry Katrina , Baje Mark , Zimmermann Lara L. , Martin Ryan , Groysman Leonid , Stern-Nezer Sara , Minokadeh Anush , Nova Alan , Huang WanTing , Cang William , Schomer Kendra
Published: June 2020

To analyze the efficacy and safety of activated prothrombin complex concentrates (aPCC) and four-factor prothrombin complex concentrates (4F-PCC) to prevent hematoma expansion in patients taking apixaban or rivaroxaban with intracranial hemorrhage (ICH). In this multicenter, retrospective study, sixty-seven ICH patients who received aPCC or 4F-PCC for known use of apixaban or rivaroxaban between February 2014 and September 2018 were included. The primary outcome was the percentage of patients who achieved excellent/good or poor hemostasis after administration of aPCC or 4F-PCC. Secondary outcomes included hospital mortality, thromboembolic events during admission, and transfusion requirements. Excellent/good hemostasis was achieved in 87% of aPCC patients, 89% of low-dose 4F-PCC [< 30 units per kilogram (kg)], and 89% of high-dose 4F-PCC (≥ 30 units per kg). There were no significant differences in excellent/good or poor hemostatic efficacy (p = 0.362). No differences were identified in transfusions 6 h prior (p = 0.087) or 12 h after (p = 0.178) the reversal agent. Mortality occurred in five patients, with no differences among the groups (p = 0.838). There were no inpatient thromboembolic events. Both aPCC and 4F-PCC appear safe and equally associated with hematoma stability in patients taking apixaban or rivaroxaban who present with ICH. Prospective studies are needed to identify a superior reversal agent when comparing andexanet alfa to hospital standard of care (4F-PCC or aPCC) and to further explore the optimal dosing strategy for patients with ICH associated with apixaban or rivaroxaban use.
Isolation and characteristics of the human rotavirus isolate CY2017
Authors: Song Yan , Liu Wei
Published: June 2020

Our study aimed to determine whether a virus from fecal samples is human rotavirus (HRV), the main pathogen that causes autumn diarrhea. Specimens were obtained from the feces from children with autumn diarrhea treated at Chuiyangliu Hospital and used to infect MA104 cells, subcultured and observed by electron microscopy. RNA was extracted, cDNA was synthesized by reverse transcription, and plaque formation and hemagglutination were assessed. The cytopathic effect (CPE) were associated with the fourth passage in subculture. CPE extracts were examined by electron microscopy, which allowed us to observe the shape of HRV particles. Amplification of the VP4 gene from HRV was used to identify the viruses as group A rotavirus. The virus causes red blood cell aggregation. The virus isolate was designated as HRV CY2017.
Microscopic dynamic observation of adhesion hysteresis friction and exploration of the influence of different pressures on friction transmission
Authors: Feng Cun-ao , Zhang De-kun , Chen Kai
Published: June 2020

The mechanism of adhesive friction between viscoelastic materials is a key question. In this study, the friction process of the adhesive interface between a friction lining and a wire rope is dynamically observed in real time to analyze the adhesion hysteresis friction intuitively and quantitatively. The adhesion is determined by the state of motion, while the relative displacement of the wire rope and lining is used to find the magnitude of the adhesive friction. The hysteresis friction is reflected by the internal deformation of the lining. The magnitude of the hysteresis friction is determined by the displacement difference (Δx) in the sliding direction of two marked points at different distances from the contact surface. The results show that the adhesion friction is proportional to the loss modulus and the hysteresis friction is proportional to the ratio of the loss modulus to the square of the storage modulus (E″/(E′2)). The frictional vibration first decreases and then increases with the increase in pressure. The K25 lining has the highest adhesion hysteresis friction and minimal frictional vibration. The result provides a simple and intuitive method for research into the friction transmission and vibration of viscoelastic materials.
Modification of Halloysite Nanotubes for Enhancement of Gas-Adsorption Capacity
Authors: Lim Sungho , Park Sooji , Sohn Daewon
Published: June 2020

Structure control and quantitative evaluation of porous materials are essential for many industrial and consumer applications of clay minerals, and nanotubular halloysite (HNT) has been used extensively for such purposes; performance enhancements are still needed, however. The objective of the present study was to improve the gas-adsorption capacity of HNT by controlling the particle size and porosity. This was accomplished through acid treatment and particle-size fractionation by centrifugation. Various particle sizes were obtained and porosities ranged from macropores to mesopores. Natural halloysite nanotubes were modified by sulfuric acid in various concentrations to selectively remove the alumina composition of the tubes. X-ray diffraction and energy dispersive X-ray spectroscopy were used to verify the mineralogical and compositional changes. Surface modification by the acid treatment increased the inner space volume of the tubes and decreased the mass of the nanotubes because of the elimination of alumina. The gas adsorption capacity of both natural and modified halloysite nanotubes was measured quantitatively using N2 adsorption and the Brunauer-Emmett-Teller (BET) method, and the morphology was determined from transmission electron microscopy (TEM) images. The results showed that the modified halloysite nanotube was 7.47 times more efficient at gas adsorption than pristine halloysite. Moreover, the dealumination of the surface increased the inner space. Greatly increased porosity characteristics, including gas adsorption and macroporosity, were obtained through modification by acid treatment.
Medicine for Hatred: Civil, Criminal, and Supernatural Justice at the Nae We Shrine Tribunal in Accra, Ghana
Authors: Roberts Jonathan , Codjoe Richard Nii Oshiu , Davison Jenny , Martin Flair , Mills Janet , Parsons Zackary
Published: June 2020

Ga proverbial wisdom holds that “hate has no medicine,” but there is a sacred court in Accra where people can calm the animosity that emerges from social conflicts. A unique form of vernacular jurisprudence has emerged at the Nae We Shrine Tribunal, which manages the consequences of civil, criminal, and supernatural crimes without raising the ire of human rights activists. Using records from this shrine court, the authors of this article demonstrate how the Tribunal offers social and spiritual wellbeing in a manner that cannot be provided by the chiefly and state judicial systems.
Chasing the rate: An interrupted time series analysis of interventions targeting reported hospital onset Clostridioides difficile, 2013–2018
Authors: Doll Michelle E. , Zhao Jinlei , Kang Le , Rittmann Barry , Alvarez Michael , Fleming Michele , Cooper Kaila , Stevens Michael P. , Bearman Gonzalo
Published: June 2020

Objective:

To assess the impact of major interventions targeting infection control and diagnostic stewardship in efforts to decrease Clostridioides difficile hospital onset rates over a 6-year period.

Design:

Interrupted time series.

Setting:

The study was conducted in an 865-bed academic medical center.

Methods:

Monthly hospital-onset C. difficile infection (HO-CDI) rates from January 2013 through January 2019 were analyzed around 5 major interventions: (1) a 2-step cleaning process in which an initial quaternary ammonium product was followed with 10% bleach for daily and terminal cleaning of rooms of patients who have tested positive for C. difficile (February 2014), (2) UV-C device for all terminal cleaning of rooms of C. difficile patients (August 2015), (3) “contact plus” isolation precautions (June 2016), (4) sporicidal peroxyacetic acid and hydrogen peroxide cleaning in all patient areas (June 2017), (5) electronic medical record (EMR) decision support tool to facilitate appropriate C. difficile test ordering (March 2018).

Results:

Environmental cleaning interventions and enhanced “contact plus” isolation did not impact HO-CDI rates. Diagnostic stewardship via EMR decision support decreased the HO-CDI rate by 6.7 per 10,000 patient days (P = .0079). When adjusting rates for test volume, the EMR decision support significance was reduced to a difference of 5.1 case reductions per 10,000 patient days (P = .0470).

Conclusion:

Multiple aggressively implemented infection control interventions targeting CDI demonstrated a disappointing impact on endemic CDI rates over 6 years. This study adds to existing data that outside of an outbreak situation, traditional infection control guidance for CDI prevention has little impact on endemic rates.
Using Eye-Tracking to Understand Decision-Making in Conjoint Experiments
Authors: Jenke Libby , Bansak Kirk , Hainmueller Jens , Hangartner Dominik
Published: June 2020

Conjoint experiments are popular, but there is a paucity of research on respondents’ underlying decision-making processes. We leverage eye-tracking methodology and a series of conjoint experiments, administered to university students and local community members, to examine how respondents process information in conjoint surveys. There are two main findings. First, attribute importance measures inferred from the stated choice data are correlated with attribute importance measures based on eye movement. This validation test supports the interpretation of common conjoint metrics, such as average marginal component effects (AMCEs), as measures of attribute importance. Second, when we experimentally increase the number of attributes and profiles in the conjoint table, respondents view a larger absolute number of cells but a smaller fraction of the total cells displayed. Moving from two to three profiles, respondents search more within-profile, rather than within-attribute, to build summary evaluations. However, respondents’ stated choices remain fairly stable regardless of the number of attributes and profiles in the conjoint table. Together, these patterns speak to the robustness of conjoint experiments and are consistent with a bounded rationality mechanism. Respondents adapt to complexity by selectively incorporating relevant new information to focus on important attributes, while ignoring less relevant information to reduce cognitive processing costs.
Protein and carbohydrate distribution among the meals: effect on metabolic parameters of patients with type 2 diabetes: a single-blinded randomised controlled trial
Authors: Nouripour Fatemeh , Mazloom Zohreh , Fararouei Mohammad , Zamani Ali
Published: June 2020

Studies have revealed that the timing of macronutrient ingestion may influence body weight and glucose tolerance. We aimed to examine the effect of high protein v. high carbohydrate intake at the evening meal on metabolic parameters of patients with type 2 diabetes. This is a single-blinded, parallel, randomised controlled trial. Ninety-six patients with type 2 diabetes, aged 32–65 years with a mean BMI of 28·5 (sd 3·4) kg/m2, were randomly assigned into one of these three groups: standard evening meal (ST), high-carbohydrate evening meal (HC) and high-protein evening meal (HP). Then, the patients were followed for 10 weeks. HbA1c, fasting blood glucose, fasting insulin, insulin resistance, TAG, LDL-cholesterol, VLDL-cholesterol, diastolic blood pressure, body weight, body fat percentage and waist circumference decreased significantly in all three groups (P < 0·05). HbA1c showed more improvement in the ST compared with the HP group (–0·45 (sd 0·36) v. –0·26 (sd 0·36)). Reductions in BMI and body weight were significantly higher in the ST compared with the HP group (P < 0·05). Reductions in total cholesterol, non-HDL-cholesterol and systolic blood pressure were significant in all groups, except for the HP group. Non-HDL-cholesterol:HDL-cholesterol remained unchanged in all groups. The results of the present study revealed that even distribution of carbohydrates and protein among meals compared with reducing carbohydrates and increasing protein at dinner may have a more beneficial effect on glycaemic control of patients with type 2 diabetes.
Preventing trauma during rigid oesophagoscopy in the edentulous patient: how I do it
Authors: Bola S , Munnings A , Corbridge R
Published: June 2020

Background

Rigid oesophagoscopy is a widely used therapeutic and diagnostic procedure. Smooth friction-free insertion of the rigid scope is important to prevent oral and oesophageal mucosal damage, as such damage can cause delays in oral intake or more serious complications such as perforation. Protection appliances such as gum guards are useful adjuncts to cushion the teeth in rigid oesophagoscopy; however, there are no specific adjuncts for the edentulous patient.

Methods

In order to investigate different adjuncts, the force required to pull a standard adult rigid oesophagoscope from a metal clamp whilst enclosed in dry gauze, wet gauze, a gum guard or sleek on gauze was recorded, and a prospective audit of post-procedural trauma was performed.

Results and conclusion

Less force was required to create movement of the scope against sleek on gauze, with a lower rate of oral trauma (8 per cent) compared to that reported in the literature. Sleek on gauze is recommended for the edentulous patient.
Government through Inaction: The Venezuelan Migratory Crisis in Ecuador
Authors: Beyers Christiaan , Nicholls Esteban
Published: June 2020

This article analyses strategies for channelling a migrant population out of a country by indirect means. Specifically, we examine the response of the Ecuadorean state to the influx of Venezuelan newcomers since 2015. We argue that this response has been characterised by inaction, rooted not in policy failures or bad governance, but rather in a strategic governmental rationality. We show how migrants are ‘herded’ out of the country as a result of a form of indirect government that works differently from other ‘anti-immigrant’ policies like forced deportations or incarceration at the border, and yet produces similar outcomes.
Report of a member-led meeting: how stable isotope techniques can enhance human nutrition research
Authors: Fielding Barbara A. , Griffin Bruce A. , Hall Wendy , Hodson Leanne , Antoni Rona , Umpleby A. Margot , Robertson Tracey , Preston Tom , Brook Matthew , Pinnick Katherine
Published: June 2020

A Nutrition Society member-led meeting was held on 9 January 2020 at The University of Surrey, UK. Sixty people registered for the event, and all were invited to participate, either through chairing a session, presenting a ‘3 min lightning talk’ or by presenting a poster. The meeting consisted of an introduction to the topic by Dr Barbara Fielding, with presentations from eight invited speakers. There were also eight lightning talks and a poster session. The meeting aimed to highlight recent research that has used stable isotope tracer techniques to understand human metabolism. Such studies have irrefutably shaped our current understanding of metabolism and yet remain a mystery to many. The meeting aimed to de-mystify their use in nutrition research.
Medea the Refugee
Authors: Kasimis Demetra
Published: June 2020

This essay reads Euripides'sMedea, the tragedy of filicide, as a critical investigation into the making of a refugee. Alongside the common claim that the drama depicting a wife murdering her children to punish an unfaithful husband is about gender inequity, I draw out another dimension: that the text's exploration of women's subordination doubles as a rendering of refuge seeking. Euripides introduces Medea as aphugas, the term for a person exiled, on the run, displaced, vulnerable, and in need of refuge. I adopt thephugasas a lens for interpreting the tragedy and generating enduring insights into dynamics of “forced” migration. Taking this political predicament as the organizing question of the text enables us to understand how dislocation from the gender-structured family can produce physical displacement and a need for asylum while casting the political meaning of Medea's kin violence in a new light.
Sir John Davies on Custom and the Common Law
Authors: Heath Eugene
Published: June 2020

Seventeenth-century English common lawyer Sir John Davies sets forth, in hisIrish Reports, a provocative and interesting argument on the nature of custom and its relation to the common law. This relatively unexplored argument shows how actions may emerge from conditions of liberty and slowly acquire qualities of social benefit and agreeability that are essential if the common law is to be identified with custom. Davies not only provides a coherent account of how custom might possess some reasonability, but he also seems to suggest that custom is unintended, thereby anticipating a theme found in eighteenth-century thinkers such as Mandeville, Hume, Ferguson, and Burke. In addition, Davies's account has important implications for political theory: the priority of the social over the political and a notion of political consent that arises via custom itself.
Opening universities’ doors for business? Marketization, the search for differentiation and employability in England
Authors: DURAZZI NICCOLO
Published: June 2020

The article investigates the causes and consequences of the increased engagement of British universities with employability and skills initiatives. By employing case studies of six universities based in England, it asks whether the increased engagement between higher education and the labour market is driven by universities or business and whether such engagement has increased the diversity of the higher education sector. Findings suggest that the alignment between labour market needs and educational provision in universities is strongly mediated by the competitive environment within which higher education institutions have been operating since the late 1990s: the higher education market – not the labour market – is the key driver for universities to engage in employability and skills initiatives. The article also questions the assumption that ‘competition’ leads to ‘differentiation’ in higher education. Rather, isomorphic tendencies seem to prevail over differentiation in the context of a highly competitive higher education market.
Adaptable and stable decentralized task allocation for hierarchical domains
Authors: Kazakova Vera A. , Sukthankar Gita R.
Published: June 2020

Many real-world domains can benefit from adaptable decentralized task allocation through emergent specialization, especially in large teams of non-communicating agents. We begin with an existing bio-inspired response threshold reinforcement approach for decentralized task allocation and extend it to handle hierarchical task domains. We test the extension on self-deployment of a large team of non-communicating agents to patrolling a hierarchically defined set of areas. Results show near-ideal performance across all areas, while minimizing wasteful task switching through the development of specializations and subsequent respecializations when area demands change. A genetic algorithm is then used to evolve even more adaptable and stable task allocation behavior, by incorporating weight and power coefficients into agents’ response threshold reinforcement action probability calculations.
International law, the paradox of plenty and the making of resource-driven conflict
Authors: Cusato Eliana
Published: June 2020

Access to and distribution of natural resources have been since immemorable time at the root of violent conflict. Over the last few decades, international institutions, legal scholars and civil society started to pay attention to the dangerous liaison between resource commodities and wars. Current debates emphasize how, through sanctions, global regulatory initiatives, and legal accountability, the governance of natural resources in conflict and post-conflict countries has improved, although international law should play a greater role to support the transition to a durable peace. The aim of this article is to illuminate the biases and limitations of dominant accounts by exploring the influence of the resource curse thesis, and its hidden propositions, upon legal developments. Using the Sierra Leonean and Liberian Truth Commissions as a case study, it shows how legal practices and discourses have contributed to a narrow understanding of resource-driven wars as started by voracious rebel groups or caused by weak/authoritarian/corrupt governments. What is obscured by the current focus on greed and ineffective resource governance? What responsibilities and forms of violence are displaced? Engaging with these questions allows us to see the dynamics through which structural injustices and distributive concerns are marginalized in existing responses to these conflicts, how the status quo is perpetuated, and the more subtle ways in which external interventions in the political economy of the Global South take place.
Theatres of Closure: Process and Performance in Inhumation Burial Rites in Early Medieval Britain
Authors: Harrington Sue , Brookes Stuart , Semple Sarah , Millard Andrew
Published: June 2020

Inhumation burials are recorded in Britain and Europe during excavations in a standardized way, especially graves of early medieval date. Just a limited number of attributes are usually foregrounded and these mainly concern skeletal identification, the grave plan and, when a burial is furnished, a list of objects, particularly metalwork, as well as occasional reference to burial structures, if present. In this paper, we argue that concealed within these recorded details are attributes that often receive little attention, but which can provide evidence for community investment in the individual funerary rite. These include grave orientation, grave morphology, the body position and the empty spaces in the grave, as well as categories of material culture. We argue here that these factors enable us to define communal burial profiles and can facilitate the identification of group perceptions and actions in dealing with death. By capitalizing on these additional aspects of funerary ritual, archaeologists can move away from a general dependency on well-furnished burials as the main stepping-off point for discussion of social and cultural issues. This has particular relevance for regions where unfurnished burial rites are the norm and where furnished rites do not rely on a wealth of metalwork.
The 40,000-Year-Old Female Figurine of Hohle Fels: Previous Assumptions and New Perspectives
Authors: Stannard Melissa K. , Langley Michelle C.
Published: June 2020

As the earliest image of a human being and the oldest piece of figurative art, the female figurine of Hohle Fels remains a significant discovery for understanding the development of symbolic behaviour in Homo sapiens. Discovered in southwestern Germany in 2008, this mammoth-ivory sculpture was found in several fragments and has always been assumed to be complete, never owning a head. In place of a head, there is instead a small loop that would allow her to be threaded, possibly to be worn as a pendant. Several hypotheses have been put forward as to her original use context, ranging from representing a fertility goddess to a pornographic figure. Yet none of these theses have ever suggested that she once had a head. Here we explore whether the female figurine of Hohle Fels was designed as a two-part piece, with the head made of perishable material culture, possibly woven plant or animal fibres; or that the artefact is a broken and reworked figurine with the head simply never found. By exploring the possibility that this figurine did originally have a second part—a head—we investigate issues surrounding the role of women and children in the Swabian Aurignacian.
Dynamical properties of Molecular Cloud Complexes at the Epoch of Reionization
Authors: Leung T. K. Daisy , Pallottini Andrea , Ferrara Andrea , Low Mordecai-Mark Mac
Published: June 2020

The Atacama Large (Sub-)millimeter Array (ALMA) has provided glimpse of the interstellar medium (ISM) properties of galaxies at the Epoch of Reionization (EoR); however, detailed understanding of their internal structure is still lacking. We present properties of molecular cloud complexes (MCCs) in a prototypical galaxy at this epoch studied in cosmological zoom-in simulations (Leung et al. 2019c). Typical MCC mass and size are comparable to nearby spirals and starburst galaxies (Mgas∼106.5Mȯ and R≃45–100 pc). MCCs are highly supersonic, with velocity dispersion of σgas≃20–100 km s−1 and pressure of P/kB ≃107.6Kcm−3, which are comparable to gas-rich starburst galaxies. In addition, we perform stability analysis to understand the origin and dynamical properties of MCCs. We find that MCCs are globally stable in the main disk of Althæa. Densest regions where star formation is expected to take place in clumps and cores on even smaller scales instead have lower virial parameter and Toomre-Q values. Detailed studies of the star-forming gas dynamics at the EoR thus require a spatial resolution of < 40 pc ( ≃ 0.01″), which is within reach of ALMA, to complement studies of stellar populations at EoR using the James Webb Space Telescope (JWST).
Theoretically modelling photoionised regions with fractal geometry in three-dimension
Authors: Jin Yifei , Kewley Lisa , Sutherland Ralph
Published: June 2020

Accurate predictions of the physics of interstellar medium (ISM) are vital for understanding galaxy formation and evolution. Modelling photoionized regions with complex geometry produces realistic ionization structures within the nebulae, providing the necessary physical predictions to interpret observational data. 3D photoionization codes built with Monte Carlo techniques provide powerful tools to produce the ionizing radiation field with fractal geometry. We present a high-resolution Monte Carlo modelling of a nebula with fractal geometry, and will further show how nebular geometry influences the emission-line behaviours. Our research has important implications for studies of emission-line ratios in high redshift galaxies.
Diving deeper into jellyfish: The rich population of jellyfish galaxies in Abell 901/2
Authors: Roman-Oliveira Fernanda , Chies-Santos Ana , Ferrari Fabrício
Published: June 2020

Jellyfish galaxies are the most extreme examples of ram pressure stripping (RPS). They represent an important path in the morphological change and quenching in galaxy clusters, however they are still not well characterised morphologically and finding them is a complex task based mainly on visual inspection. We present a study on the properties of a large sample of jellyfish candidates in the multi-cluster system A901/2. We find evidence that the multi-cluster is triggering RPS events in preferential regions in the system and that these galaxies have enhanced specific star formation rates. We also use the software Morfometryka in order to analyse the unique morphometric features in jellyfish galaxies providing a better comprehension of their physical state and future. This can help unravel the physical processes behind such extreme morphologies as well as possibly automatising the search for jellyfish galaxy candidates in large surveys in the next era of instruments.
Molecular gas across cosmic time
Authors: Magdis Georgios E.
Published: June 2020

We have entered an era where the gas mass estimates of distant galaxies do not rely on a single tracer but rather on an inventory of different and independent methods, much like the case for the determination of the star formation rate (SFR) of the galaxies. This is crucial as the traditional Mgas tracers, i.e. low-J CO transition lines and dust continuum emission are becoming highly uncertain as we move to higher redshifts due to metallicity and CMB effects. Here, we present a homogeneous and statistically significant investigation of the use of atomic carbon as an alternative Mgas tracer (Valentino et al.2018) and provide evidence of optically thick far-IR emission in high−z starbursts that point towards higher dust temperatures and lower dust and gas mass estimates than previously inferred (Cortzen et al.2019, submitted). Finally, we present direct observations of the effect of the CMB on the far-IR SEDs of high-z SBs, manifested by unphyscally large (β = 2.5–3.5) apparent spectral indexes in R-J tail (Jin et al. 2019, submitted).
Molecular gas and dust emission in a z = 3.63 strongly lensed starburst merger at sub-kiloparsec scales
Authors: Yang C. , Gavazzi R. , Beelen A. , Cox P. , Omont A. , Lehnert M. D.
Published: June 2020

We present 0.″2–0.″4 resolution ALMA images of the submillimeter dust continuum and the CO, H2O, and H2O+ line emission in a z = 3.63 strongly lensed dusty starburst. We construct the lens model for the system with an MCMC technique. While the average magnification for the dust continuum is about 11, the magnification of the line emission varies from 5 to 22 across the source, resolving the source down to sub-kpc scales. The ISM content reveals that it is a pre-coalescence major merger of two ultra-luminous infrared galaxies, both with a large amount of molecular gas reservoir. The approaching galaxy in the south shows no apparent kinematic structure with a half-light radius of 0.4 kpc, while the preceding one resembles a 1.2 kpc rotating disk, separated by a projected distance of 1.3 kpc. The distribution of dust and gas emission suggests a large amount of cold ISM concentrated in the interacting region.
More than star formation: High-J CO SLEDs of high-z galaxies
Authors: Sharon Chelsea E. , Chng Reni , Gurara Kebron K. , Weiß Axel , Darling Jeremy , Riechers Dominik , Ferkinhoff Carl
Published: June 2020

Theoretical work suggests that AGNs play an important role in quenching star formation in massive galaxies. In addition to molecular outflows observed in the local universe, emission from very high-J CO rotational transitions have been a key piece of evidence for AGN directly affecting the molecular gas reservoirs that fuel star formation. However, very few observations exist of CO rotational lines past the peak of the CO spectral line energy distribution (SLED) for galaxies in the early universe. Here we present new ALMA observations of high-J CO rotational lines (from CO(5–4) to CO(16–15)) in six z > 2 IR-bright systems, including several sources not known to contain a strong AGN for comparison. We detect significant amounts of high-excitation CO emission that suggests the presence of energy sources beyond UV-heating.
JWST advanced deep extragalactic survey: NIRCam imaging to z > 10
Authors: Rieke Marcia
Published: June 2020

The JWST Advanced Deep Extragalactic Survey (JADES) is a joint program of the JWST NIRCam and NIRSpec Guaranteed Time Observation (GTO) teams involving over 800 hours of observation. This paper describes the imaging portion of the program which covers nearly 200 square arc minutes divided between two well-studied fields with excellent supporting data (e.g. from Chandra, ALMA, and HST-CANDELS): GOODS North and South, including the Ultra Deep Field. NIRCam imaging will enable the study of galaxy evolution to z ∼ 10 and higher using multi-color imaging with 9 filters covering 0.9 to 5 microns. Such data will provide photometric redshifts and a wealth of data for constructing luminosity and mass functions. A key component of the program is rapid turn around of imaging into NIRSpec target lists. Preparing for this program has benefited from the development of a mock catalog and simulated imaging to test these processes.
What drives the [CII]/FIR deficit in submillimeter galaxies?
Authors: Rybak Matus , Hodge J. A. , Calistro Rivera G. ,   ALESS Collaboration
Published: June 2020

Submillimeter galaxies at redshift z⩾1 show a pronounced [CII]/FIR deficit down to sub-kpc scales; however, the physical origin of this deficit remains poorly understood. We use resolved ALMA observations of the [CII], FIR and CO(3–2) emission in two z = 3 SMGs to distinguish between the different proposed scenarios; the thermal saturation of the [CII] emission is the most likely explanation.
Galactic outflows at high spatial resolution via gravitational lensing
Authors: Spilker Justin
Published: June 2020

The completion of the Atacama Large Millimeter/submillimeter Array (ALMA) has led to the ability to make observations with unprecedented resolution at sub-millimeter wavelengths, allowing novel probes of the ISM and kinematics of high-redshift galaxies. Because they are magnified by foreground galaxies or clusters, gravitationally lensed galaxies allow the highest possible spatial resolution to be obtained, and/or a sharp reduction in the observing time required to detect faint objects or spectral lines. These benefits have made lensed galaxies useful benchmark systems for ALMA, enabling a wide variety of science cases. Here I focus in particular on spatially-resolved observations of massive galactic outflows in the very distantz> 4 universe, summarizing plausible tracers of the cold molecular phase of these outflows. The prospects of jointJWSTand ALMA observations will be revolutionary, including the chance to take a full census of galactic outflows in multiple gas phases at matched spatial resolution.
The interstellar medium content of galaxies in the ALMA era
Authors: Aravena Manuel
Published: June 2020

The advent of the Atacama Large Millimeter/submillimeter Array (ALMA) has enabled a new era for studies of the formation and assembly of distant galaxies. Cosmological deep field surveys with ALMA and other interferometers have flourished in the last few years covering wide ranges of galaxy properties and redshift, and allowing us to gain critical insights into the physical mechanisms behind the galaxy growth. Here, we present a brief review of recent studies that aim to characterize the interstellar medium properties of galaxies at high redshift (z > 1), focusing on blank-field ALMA surveys of dust continuum and molecular line emission. In particular, we show recent results from the ALMA Spectroscopic Survey in the Hubble Ultra Deep Field (ASPECS) large program.
Clustering of galaxies around quasars at z ∼ 4
Authors: García-Vergara Cristina , Hennawi Joseph F. , Felipe Barrientos L. , Arrigoni Battaia Fabrizio
Published: June 2020

We conduct a survey for Lyman break galaxies (LBGs) and Lyman alpha emitters (LAEs) in the environs of six and 17 z ∼ 4 quasars respectively, probing scales of R≲9h−1Mpc. We detect an enhancement of galaxies (both LBGs and LAEs) in quasar fields, a positive and strong quasar-galaxy cross-correlation function, consistent with a power-law shape, and a strong galaxy auto-correlation function in quasar fields. The three mentioned results are all indicators that quasars trace massive dark matter halos in the early universe.
ALMA Deep Field in the SSA22 proto-cluster at z = 3
Authors: Umehata Hideki
Published: June 2020

Galaxies and nuclei in dense environment at high redshift provide a good laboratory to investigate accelerated, most extreme evolution of galaxies. The SSA22 proto-cluster at z = 3.1 is known to have a three-dimensional 50 (comoving) Mpc-scale filamentary structure, traced by Lyα emitters, which makes the field a suitable target in this regard. To identify dust-obscured star-formation, a contiguous 20 arcmin2 region at the node of the cosmic structure was observed in ALMA band 6. In total 57 ALMA sources have been identified above 5σ, which makes the field one of the richest field in ALMA-identified (sub)millimeter galaxies. The follow-up spectroscopy confirmed about 20 sources as exact proto-cluster members so far. Together with high X-ray AGN fraction, our results suggest that the vigorous star formation activity and the growth of super massive black holes occurred simultaneously in the densest regions at z ∼ 3.
Neutral gas and the escape of ionizing radiation: Lessons from the low-redshift Green Peas
Authors: Jaskot Anne , McKinney Jed , Dowd Tara , Oey Sally , Yun Min , Scarlata Claudia , Lowenthal James
Published: June 2020

How galaxies reionized the universe remains an open question, but we can gain insights from the low-redshift Green Pea galaxies, one of the only known populations of Lyman continuum (LyC) emitters. Using VLA H i 21 cm observations and HST UV spectra of Green Peas, we investigate how neutral gas content and geometry influence LyC and Lyα escape. Our results suggest that LyC Emitters may have high ratios of star formation rate to H i mass. Low gas covering fractions are common among the population, but not all sightlines are optically thin. Based on the observed relationship between high ionization parameters, low metallicities, and narrow Lyα profiles, we propose that weak stellar feedback at low metallicities results in a gas geometry of dense clumps within a low-density medium, which facilitates Lyα and LyC escape. We address the implications of these results for identifying LyC emitters at high redshift with JWST and ALMA.
Modeling dust in a universe of galaxies
Authors: Narayanan Desika , Li Qi , Davé Romeel , Conroy Charlie , Johnson Benjamin D. , Popping Gergo
Published: June 2020

In this invited talk, we discuss the physics of the lifecycle of dust in the context of galaxy formation simulations. After outlining the basic physical processes, we apply algorithms for the formation, growth, and destruction of dust in the ISM to a state-of-the-art cosmological simulation to develop a model for the evolution of the dust to gas and dust to metals ratios in galaxies. We show that while modern simulations are able to match the observed dust mass function at redshift z = 0, most models underpredict the observed mass function at high-redshift (z = 2). We then show the power of these techniques by expanding our model to include a spectrum of dust sizes, and make initial predictions for extinction laws in local galaxies.
Local analogs of high-redshift galaxies: Metallicity calibrations at high-redshift
Authors: Bian Fuyan , Kewley Lisa J. , Groves Brent , Dopita Michael A.
Published: June 2020

We study the metallicity calibrations in high-redshift galaxies using a sample of local analogs of high-redshift galaxies selected from the SDSS survey. Located in the same region on the BPT diagram as star-forming galaxies at z ∼ 2, these high-redshift analogs share the same ionized ISM conditions as high-redshift galaxies. We establish empirical metallicity calibrations between the direct gas-phase oxygen abundances and varieties of metallicity indicators in our local analogs using direct Te method. These new metallicity calibrations are the best means to measure the metallicity in high-redshift galaxies. There exist significant offsets between these new high-redshift metallicity calibrations and local calibrations. Such offsets are mainly driven by the evolution of the ionized ISM conditions from high-z to low-z.
Galaxy build-up at cosmic dawn: Insights from deep observations with Hubble, Spitzer, and ALMA
Authors: Oesch Pascal
Published: June 2020

Over the last few years, great progress has been made in understanding the build-up of the first generations of galaxies based on deep optical and near-infrared imaging from the Hubble Space Telescope. However, HST only samples the rest-frame UV light of galaxies at z …4, providing only limited information on the dust obscuration and on stellar masses of these sources. Fortunately, several Spitzer/IRAC programs have complemented the extragalactic HST fields with ultra-deep imaging data, allowing for a rest-frame optical view on early galaxies. Together with first ALMA/ NOEMA (sub)mm observations on distant galaxies, we are starting to gain a more and more complete picture of galaxy star-formation and mass build-up in the early universe. In this talk, I will present an overview of our current understanding of normal star-forming galaxies at z > 3 based the combination of HST+Spitzer+ALMA/NOEMA data. In particular, I will show how HST as already pushed into JWST territory with the discovery and spectroscopic confirmation of a galaxy at z = 11.1 ± 0.1, only : 400 Myr after the Big Bang. I will also highlight some of the exciting possibilities that lie ahead with JWST to push the spectroscopic frontier to the cosmic dawn and to finally probe the physics of early galaxies.
Probing the faintest galaxy population at the epoch of reionization with gravitational lensing
Authors: Atek Hakim
Published: June 2020

Ultra-deep observations of blank fields with the Hubble Space Telescope have made important inroads in characterizing galaxy populations at redshift z = 6 – 10. Gravitational lensing by massive galaxy clusters offers a new route to identify the faintest sources at the epoch of reionization. In particular, thanks to the Hubble Frontier Fields program, we robustly pushed the detection limit down to MAB = − 15 mag at z ∼ 6. I will present the latest results based on the complete dataset of the HFF clusters and parallel fields, and their implications on the ability of galaxies to reionize the Universe. I will also discuss the results of a comprehensive end-to-end modeling effort towards constraining the systematic uncertainties of the lens models, which are currently the last hurdle before extending the UV LF to fainter luminosities. Finally, I will discuss the great discoveries awaiting combination of such cosmic lenses with the upcoming James Webb Space Telescope and the exciting opportunity to probe the turnover of the UV LF, hence the limit of the star formation process at those early epochs.
Early galaxy formation and its large-scale effects
Authors: Dayal Pratika
Published: June 2020

Galaxy formation in the first billion years mark a time of great upheaval in the history of the Universe: the first galaxies started both the ‘metal age’ as well as the era of cosmic reionization. I will start by reviewing the dust production mechanisms and dust masses for high-redshift galaxies which will be revolutionized in the ALMA era. I will then show how the JWST will be an invaluable experiment to shed light on the impact of reionization feedback on early galaxy formation. As we look forward towards the era of 21cm cosmology, I will highlight the crucial and urgent synergies required between 21cm facilities (such as the SKA) and galaxy experiments (JWST, E-ELT and Subaru to name a few) to understand the physics of the epoch of reionization that remains a crucial frontier in the field of astrophysics and physical cosmology. Time permitting, I will try to give a flavour of how the assembly of early galaxies, accessible with the forthcoming JWST, can provide a powerful testbed for Dark Matter models beyond ‘Cold Dark Matter’.
A review of spectral energy distribution modeling at high-redshift
Authors: Charlot Stéphane
Published: June 2020

I will review recent developments in the modeling of high-redshift galaxy spectra, focusing in particular on the rest-frame ultraviolet and optical emission from young stellar populations and the interstellar medium.