bluuebunny/crossref_metadata_2025 huggingface dataset:
Phase Transitions and Microstructural Changes During Oxidation and Reduction of a Weathered Ilmenite Concentrate
Authors: Salehi Hossein , Seim Stian , Kolbeinsen Leiv , Safarian Jafar
Published: February 2021

The present work aims to investigate the link between the oxidation and reduction of a weathered ilmenite concentrate in terms of phase transitions, microstructural changes, and element distribution. An ilmenite concentrate sample was pelletized and fired at 1000 °C in air, and as a result, the pellets were oxidized. The oxidized pellets were reduced by hydrogen gas at 1000 °C, which yielded almost complete metallization of the iron content of the pellets. The ore and the pellets were characterized in each step by XRD and SEM techniques, and distribution of elements and phases were investigated. Ilmenite, pseudorutile, and rutile were the main phases detected in the ilmenite concentrate sample, and depending on the weathering degree of the particles, different fractions of the phases were identified in their microstructure. It was found that irregular rutile grains dispersed in a pseudobrookite matrix is the morphology of the oxidized ilmenite phase. However, increasing microcracks and porosities were the only microstructural changes in the pseudorutile phase after oxidation in air. Studying the specific types of the ore particles and their oxidized and reduced forms indicated that the phase distribution in the ilmenite ore particles dictates the phase distribution in the oxidized and reduced ones. Results show that the morphology of the reduced particles includes a titanium (III) oxide matrix in which reduced iron globules are dispersed.
Biologia Futura: stories about the functions of β2-integrins in human phagocytes
Authors: Bajtay Zsuzsa
Published: February 2021

Integrins are essential membrane proteins that provide a tightly regulated link between the extracellular matrix and the intracellular cytoskeletal network. These cell surface proteins are composed of a non-covalently bound α chain and β chain. The leukocyte-specific complement receptor 3 (CR3, αMβ2, CD11b/CD18) and complement receptor 4 (CR4, αXβ2, CD11c/CD18) belong to the family of β2-integrins. These receptors bind multiple ligands like iC3b, ICAMs, fibrinogen or LPS, thus allowing them to partake in phagocytosis, cellular adhesion, extracellular matrix rearrangement and migration. CR3 and CR4 were generally expected to mediate identical functions due to their structural homology, overlapping ligand specificity and parallel expression on human phagocytes. Despite their similarities, the expression level and function of these receptors differ in a cell-type-specific manner, both under physiological and inflammatory conditions.

We investigated comprehensively the individual role of CR3 and CR4 in various functions of human phagocytes, and we proved that there is a “division of labour” between these two receptors. In this review, I will summarize our current knowledge about this area.
The Problem of the Actress in Modern German Theater and Thought
Authors: Jackson S. E.
Published: February 2021

Reconstructs the constitutive role that German actresses played on and off the stage in shaping not only modernist theater aesthetics and performance practices, but also influential strains of modern thought.
The British Navy in the Caribbean
Authors: Grainger John D.
Published: February 2021

A survey of the activities of the British navy in the Caribbean from the voyages of sixteenth century English adventurers such as John Hawkins and Francis Drake through the great wars of the seventeenth and eighteenth centuries against the Dutch, Spanish and French and Britain's declining role thereafter.
“Could You, Would You, Should You?” Regulating Cross-Border Travel Through COVID-19 Soft Law in Finland
Authors: KORKEA-AHO Emilia , SCHEININ Martin
Published: February 2021

In the coronavirus pandemic that has swept the world, the Finnish Government, like many of its peers, has issued policy measures to combat the virus. Many of these measures have been implemented in law, including measures taken under the Emergency Powers Act, or by ministries and regional and local authorities exercising their legal powers. However, some governmental policy measures have been implemented using non-binding guidelines and recommendations. Using border travel recommendations as a case study, this article critically evaluates governmental soft law-making. The debacle over the use of soft law to fight the pandemic in Finland revealed fundamental misunderstandings about the processes and circumstances under which instruments conceived as soft law can be issued, as well as a lack of attention to their effects from a fundamental rights perspective.
Killing me Softly? Scrutinising the Role of Soft Law in Greece’s Response to COVID-19
Authors: TSOURDI Evangelia (Lilian) , VAVOULA Niovi
Published: February 2021

Greece emerged as the EU’s poster child in the fight against COVID-19 during the first few months of the pandemic. In this contribution, we assess Greece’s use of soft regulation in its regulatory response to COVID-19. Using “acts of legislative content”, which can be broadly conceptualised as softly adopted hard law, the Greek government largely achieved flexibility and simplified adoption procedures without having to resort to soft law per se. The role of soft law was limited - it complemented hard law rather than constituting the primary basis of COVID-19 restrictions - but not completely negligible. Soft law instruments regulated the processing of personal data, and was also pivotal in clarifying the criminal sanctioning of COVID-related rule violations. Greece’s success in handling the first wave of the pandemic, while effective, was arguably unfair to asylum seekers who saw their right to apply for asylum curtailed, and their right to freedom of movement restricted when limitations on the rest of the population were lifted. With a second wave of infections currently in full swing, it is imperative to keep scrutinising regulatory responses to ensure that they place the health and dignity of every individual (whoever they might be) at their core and fully respect their fundamental rights.
Domestic Soft Law Regulation during the COVID-19 Lockdown in Hungary: A Novel Regulatory Approach to a Unique Global Challenge
Authors: LÁNCOS Petra Lea , CHRISTIÁN László
Published: February 2021

On 13 March 2020 the Hungarian Government announced the immediate closure of all schools throughout the country to prevent the spread of COVID-19 forcing several hundred thousand children to learn from home, and teachers to ensure their education. The Hungarian Educational Authority hurried to issue recommendations on the use of digital education tools. During the COVID-19 pandemic and the special legal order consequently introduced by the Hungarian Government, Hungary has seen the emergence of such non-binding measures adopted by public entities, complementing governmental action against the pandemic, with the aim of providing guidance to bodies exercising a public service function (“addressees”). These protective measures adopted under the special legal order are deemed to be successful and are largely followed by the addressees. Since soft law has hitherto been neglected by both Hungarian administrative governance and the legal literature, the recent burgeoning of non-binding measures deserves scholarly attention. In this article, we set out to map the specific context of the emergence of domestic soft law and the conditions for its adoption and reception, relying on our case study conducted in respect of the National Educational Authority’s recommendations.
The Role of COVID-19 Soft Law Measures in Italy: Much Ado about Nothing?
Authors: APERIO BELLA Flaminia , LAURI Cristiana , CAPRA Giorgio
Published: February 2021

This article considers the role of non-binding legal instruments adopted in Italy against the SARS-CoV-2 virus in the early months of 2020. To verify whether the use of such instruments restricted fundamental and human rights beyond constitutional and legal limits, the article first gives an overview of hard law measures adopted in Italy against the coronavirus. It then focuses on soft law measures, the use of which became significant only in Phase II of Italy's response to COVID-19 and argues that non-binding legal instruments provided the public with instructions on gradually returning to normal life. This contribution contains case studies on the soft law measures adopted in relation to private economic enterprise and freedom of worship. Italian soft law deployed during the COVID-19 epidemic was borne out of coordination between the state and the Regions and as the result of (even informal) dialogue with the relevant stakeholders. Despite some criticism of the soft law measures used, their role in restricting constitutionally granted rights was marginal, because only hard law measures adopted nationally and locally limited personal rights and freedoms in order to contain the pandemic.
Looking for twins: how to build better counterfactuals with matching
Authors: Costalli Stefano , Negri Fedra
Published: February 2021

A primary challenge for researchers that make use of observational data is selection bias (i.e. the units of analysis exhibit systematic differences and dis-homogeneities due to non-random selection into treatment). This article encourages researchers in acknowledging this problem and discusses how and – more importantly – under which assumptions they may resort to statistical matching techniques to reduce the imbalance in the empirical distribution of pre-treatment observable variables between the treatment and control groups. With the aim of providing a practical guidance, the article engages with the evaluation of the effectiveness of peacekeeping missions in the case of the Bosnian civil war, a research topic in which selection bias is a structural feature of the observational data researchers have to use, and shows how to apply the Coarsened Exact Matching (CEM), the most widely used matching algorithm in the fields of Political Science and International Relations.
Nation and Migration in Late-Ottoman Spheres of (Legal) Belonging: A Comparative Look at Laws on Nationality
Authors: Akcasu A. Ebru
Published: February 2021

The last century of the Ottoman state’s existence witnessed the transformation of the term “Ottoman” from an elite, class-based, and exclusive designation to one including and identifying all whose allegiances were tied to the state. Despite this semantic shift, the verdict is still out on the question of late-Ottoman inclusivity. Indeed, exclusivist is a term more frequently coupled with policy and law. Though the former can be considered exclusivist in many instances from the late 19th century through the dissolution of the empire, the designation does not fit the legal framework and terminology that articulated belonging. To recognize this, it is imperative to approach the 1869 Ottoman Nationality Law from a comparative perspective, especially, though not strictly, with reference to Great Power laws, since these legalities are the yardstick by which Ottoman rational modernity has been measured. This article considers access to actual and potential membership in various nationality laws in relation to their Ottoman counterpart and concludes that the exclusivist designation is questionable. Instead, Ottoman law does not present an anomaly and was in many instances both more expansive and more inclusive than others—even if it has been subjected to a different vocabulary than contemporaneous laws with similar stipulations.
Early Miocene calc-alkaline felsic tuffs within deep-marine turbidites in the Kyrenia Range, north Cyprus, with a possible post-collisional eruptive centre in western Anatolia
Authors: Chen Guohui , Robertson Alastair H. F.
Published: February 2021

Felsic tuff as a direct fallout deposit is known from one small area in the Kyrenia Range, north Cyprus, within deep-sea terrigenous turbidites. Nearby tuffaceous siltstones contain compositionally similar felsic volcanic rocks (c. 5–10%), mixed with terrigenous material. Sedimentary evidence indicates that the fallout tuff was variable reworked locally, whereas the tuffaceous siltstones are interpreted as turbidites mixed with terrigenous material derived from Anatolia. U–Pb dating of zircons that were extracted from a sample of relatively homogeneous tuff yielded a dominant age of 16.64 ± 0.12 Ma (Burdigalian). Zircon trace-element analysis indicates predominant derivation from within-plate-type felsic magma. Whole-rock chemical analysis of the tuffaceous sediments as a whole is compatible with a felsic arc source, similar to the post-collisional magmatism within Anatolia. Regional comparisons suggest that the nearest volcanism of similar age and composition is locatedc. 500 km away, within the Kırka area (Eskişehir region) of the Western Anatolia Volcanic Province. Evidence of tephra dispersal in the western Mediterranean region and climatic modelling suggests E-wards prevailing winds and therefore tephra transport over southern Anatolia and adjacent areas during early Miocene time. The north Cyprus tuffs could represent powerful Minoan (Plinian)-type eruptions in western Anatolia, coupled with SE-wards tephra transport during and soon after the onset of post-collisional magmatism.
The Janus Face of the Liberal International Information Order: When Global Institutions Are Self-Undermining
Authors: Farrell Henry , Newman Abraham L.
Published: February 2021

Scholars and policymakers long believed that norms of global information openness and private-sector governance helped to sustain and promote liberalism. These norms are being increasingly contested within liberal democracies. In this article, we argue that a key source of debate over the Liberal International Information Order (LIIO), a sub-order of the Liberal International Order (LIO), is generated internally by “self-undermining feedback effects,” that is, mechanisms through which institutional arrangements undermine their own political conditions of survival over time. Empirically, we demonstrate how global governance of the Internet, transnational disinformation campaigns, and domestic information governance interact to sow the seeds of this contention. In particular, illiberal states converted norms of openness into a vector of attack, unsettling political bargains in liberal states concerning the LIIO. More generally, we set out a broader research agenda to show how the international relations discipline might better understand institutional change as well as the informational aspects of the current crisis in the LIO.
Populism in Place: The Economic Geography of the Globalization Backlash
Authors: Broz J. Lawrence , Frieden Jeffry , Weymouth Stephen
Published: February 2021

A populist backlash to globalization has ushered in nationalist governments and challenged core features of the Liberal International Order. Although startling in scope and urgency, the populist wave has been developing in declining regions of wealthy countries for some time. Trade, offshoring, and automation have steadily reduced the number of available jobs and the wages of industrial workers since at least the 1970s. The decline in manufacturing employment initiated the deterioration of social and economic conditions in affected communities, exacerbating inequalities between depressed rural areas and small cities and towns, on the one hand, and thriving cities, on the other. The global financial crisis of 2008 catalyzed these divisions, as communities already in decline suffered deeper and longer economic downturns than metropolitan areas, where superstar knowledge, technology, and service-oriented firms agglomerate. We document many of these trends across the United States and Europe, and demonstrate that populist support is strongest in communities that experienced long-term economic and social decline. Institutional differences in labor markets and electoral rules across developed democracies may explain some of the variation in populists’ electoral success. Renewed support for the Liberal International Order may require a rejuvenation of distressed communities and a reduction of stark regional inequalities.
Preliminary observations on abundance and distribution of fish fauna in a canyon of the Bay of Biscay (ICES Division 8c)
Authors: Diez G. , Arregi L. , Basterretxea M. , Cuende E. , Oyarzabal I.
Published: February 2021

The changes in abundance and biodiversity of deep-sea fish fauna are described based on an annual deep-water longline survey with data collected during the period 2015–2019 in the Basque Country continental Slope (ICES Division 8c). The sampling scheme included hauls in four 400 m strata, from 650–2250 m deep. The DST sensors installed in the main line have allowed us to set an accurate soak time for each haul, and they were used to calculate fishing effort and CPUE by haul. The catchability of the fishing gear indicated that 15% of the total hooks deployed in the five-year period were able to fish, and that the bottom longline was very effective in fishing a wide number of different species in all depth ranges. The fishing gear caught 14 different species of sharks (13 deepwater and one pelagic), two chimaeras and nine teleosts. The abundance and biomass registered on the hooks attached to the bottom were between three and four times higher than in the floating sections, and the highest CPUE and biomass were recorded between 1051–1450 m, from 2015 to 2017, and in the 1451–1850 m strata, but they do not show any clear trend throughout the five years of the series.
Genetic contributions to anxiety disorders: where we are and where we are heading
Authors: Ask Helga , Cheesman Rosa , Jami Eshim S. , Levey Daniel F. , Purves Kirstin L. , Weber Heike
Published: February 2021

Anxiety disorders are among the most common psychiatric disorders worldwide. They often onset early in life, with symptoms and consequences that can persist for decades. This makes anxiety disorders some of the most debilitating and costly disorders of our time. Although much is known about the synaptic and circuit mechanisms of fear and anxiety, research on the underlying genetics has lagged behind that of other psychiatric disorders. However, alongside the formation of the Psychiatric Genomic Consortium Anxiety workgroup, progress is rapidly advancing, offering opportunities for future research.

Here we review current knowledge about the genetics of anxiety across the lifespan from genetically informative designs (i.e. twin studies and molecular genetics). We include studies of specific anxiety disorders (e.g. panic disorder, generalised anxiety disorder) as well as those using dimensional measures of trait anxiety. We particularly address findings from large-scale genome-wide association studies and show how such discoveries may provide opportunities for translation into improved or new therapeutics for affected individuals. Finally, we describe how discoveries in anxiety genetics open the door to numerous new research possibilities, such as the investigation of specific gene–environment interactions and the disentangling of causal associations with related traits and disorders.

We discuss how the field of anxiety genetics is expected to move forward. In addition to the obvious need for larger sample sizes in genome-wide studies, we highlight the need for studies among young people, focusing on specific underlying dimensional traits or components of anxiety.
Feminist Mobilization and the Abortion Debate in Latin America: Lessons from Argentina
Authors: Daby Mariela , Moseley Mason W.
Published: February 2021

When Argentine president Mauricio Macri announced in March 2018 that he supported a “responsible and mature” national debate regarding the decriminalization of abortion, it took many by surprise. In a Catholic country with a center-right government, where public opinion regarding abortion had hardly moved in decades—why would the abortion debate surface in Argentina when it did? Our answer is grounded in the social movements literature, as we argue that the organizational framework necessary for growing the decriminalization movement had already been built by an emergent feminist movement of unprecedented scope and influence: Ni Una Menos. By expanding the movement's social justice frame from gender violence to encompass abortion rights, feminist activists were able to change public opinion and expand the scope of debate, making salient an issue that had long been politically untouchable. We marshal evidence from multiple surveys carried out before, during, and after the abortion debate and in-depth interviews to shed light on the sources of abortion rights movements in unlikely contexts.
Tort reform: do details matter?
Authors: Childers Rachel G.
Published: February 2021

One explanation for increases in health care costs has been malpractice lawsuits. States have introduced several types of tort reforms to control increases in health care costs. This paper adds to the literature by examining how the differences in joint and several liability (JSL) reforms affect the state-specific growth rate in health care expenditures. Additionally, the paper addresses the potential for a fundamental difference between states that pass different types of liability reforms. The results show that JSL reforms that limit joint liability based on percentage of blame have statistically and economically significant impacts on health care expenditure growth rates.
This Search for Alien Life Starts with Destroying Bacteria on Earth
Authors: Wendel JoAnna
Published: February 2021

Someday, a catalog of molecular fragments might help scientists identify extraterrestrial life on our solar system’s icy moons.
The dopamine D1–D2DR complex in the rat spinal cord promotes neuropathic pain by increasing neuronal excitability after chronic constriction injury
Authors: Bao Yi-Ni , Dai Wen-Ling , Fan Ji-Fa , Ma Bin , Li Shan-Shan , Zhao Wan-Li , Yu Bo-Yang , Liu Ji-Hua
Published: February 2021

Dopamine D1 receptor (D1DR) and D2 receptor (D2DR) are closely associated with pain modulation, but their exact effects on neuropathic pain and the underlying mechanisms remain to be identified. Our research revealed that intrathecal administration of D1DR and D2DR antagonists inhibited D1–D2DR complex formation and ameliorated mechanical and thermal hypersensitivity in chronic constriction injury (CCI) rats. The D1–D2DR complex was formed in the rat spinal cord, and the antinociceptive effects of D1DR and D2DR antagonists could be reversed by D1DR, D2DR, and D1–D2DR agonists. Gαq, PLC, and IP3 inhibitors also alleviated CCI-induced neuropathic pain. D1DR, D2DR, and D1–D2DR complex agonists all increased the intracellular calcium concentration in primary cultured spinal neurons, and this increase could be reversed by D1DR, D2DR antagonists and Gαq, IP3, PLC inhibitors. D1DR and D2DR antagonists significantly reduced the expression of p-PKC γ, p-CaMKII, p-CREB, and p-MAPKs. Levo-corydalmine (l-CDL), a monomeric compound in Corydalis yanhusuo W.T. Wang, was found to obviously suppress the formation of the spinal D1–D2DR complex to alleviate neuropathic pain in CCI rats and to decrease the intracellular calcium concentration in spinal neurons. l-CDL-induced inhibition of p-PKC γ, p-MAPKs, p-CREB, and p-CaMKII was also reversed by D1DR, D2DR, and D1–D2DR complex agonists. In conclusion, these results indicate that D1DR and D2DR form a complex and in turn couple with the Gαq protein to increase neuronal excitability via PKC γ, CaMKII, MAPK, and CREB signaling in the spinal cords of CCI rats; thus, they may serve as potential drug targets for neuropathic pain therapy.
Antioxidant treatment ameliorates prefrontal hypomyelination and cognitive deficits in a rat model of schizophrenia
Authors: Maas D. A. , Eijsink V. D. , van Hulten J. A. , Panic R. , De Weerd P. , Homberg J. R. , Vallès A. , Nait-Oumesmar B. , Martens G. J. M.
Published: February 2021

Cognitive dysfunction in schizophrenia (SZ) is thought to arise from neurodevelopmental abnormalities that include interneuron hypomyelination in the prefrontal cortex (PFC). Here we report that RNA-sequencing of the medial (m)PFC of the APO-SUS rat model with SZ-relevant cognitive inflexibility revealed antioxidant metabolism as the most-enriched differentially expressed pathway. Antioxidant-related gene expression was altered throughout postnatal development and preceded hypomyelination. Furthermore, reduced glutathione levels and increased mitochondria numbers were observed in the mPFC. Strikingly, chronic treatment with the glutathione precursor N-acetylcysteine (NAC) from postnatal days 5–90 restored not only antioxidant-related mRNA expression and mitochondria numbers, but also myelin-related mRNA expression and mPFC-dependent cognitive dysfunction, while blood glutathione levels remained unaffected. The promyelinating effect of NAC was at least partly due to a positive effect on oligodendrocyte lineage progression. Together, our findings highlight that oxidative stress may contribute to cognitive symptoms in the APO-SUS rat model of SZ and encourage antioxidant therapy in early phases of SZ.
Late-life depression accentuates cognitive weaknesses in older adults with small vessel disease
Authors: Oberlin Lauren E. , Respino Matteo , Victoria Lindsay , Abreu Lila , Hoptman Matthew J. , Alexopoulos George S. , Gunning Faith M.
Published: February 2021

Neuroimaging features of small vessel disease (SVD) are highly prevalent in older adulthood and associated with significant variability in clinical symptoms, yet the factors predicting these symptom disparities are poorly understood. We employed a novel metric of SVD, peak width of skeletonized mean diffusivity (PSMD), to elucidate the relationship of late-life depression (LLD) to the cognitive presentation of vascular pathology. A total of 109 older adults without a diagnosis of a neurocognitive disorder were enrolled in the study; 44 with major depressive disorder and 65 age-matched controls. Subjects completed neuropsychological testing and magnetic resonance imaging including FLAIR and diffusion tensor imaging sequences, from which white matter hyperintensity volume and diffusion metrics (fractional anisotropy, mean diffusivity, PSMD) were quantified. In hierarchical models, the relationship between vascular burden and cognitive performance varied as a function of diagnostic status, such that the negative association between PSMD and processing speed was significantly stronger in participants with LLD compared to controls. Greater PSMD also predicted poorer performance on delayed memory and executive function tasks specifically among those with LLD, while there were no associations between PSMD and task performance among controls. PSMD outperformed conventional SVD and diffusion markers in predicting cognitive performance and dysexecutive behaviors in participants with LLD. These data suggest that LLD may confer a vulnerability to the cognitive manifestations of white matter abnormalities in older adulthood. PSMD, a novel biomarker of diffuse microstructural changes in SVD, may be a more sensitive marker of subtle cognitive deficits stemming from vascular pathology in LLD.
Early diet in preterm infants and later cognition: 10-year follow-up of a randomized controlled trial
Authors: Embleton Nicholas D. , Wood Claire L. , Pearce Mark S. , Brunskill Greta , Grahame Victoria
Published: February 2021

Background

Achieving adequate nutrition in preterm infants is challenging. The post-discharge period may be critical for influencing growth and cognitive outcomes. We studied the effects of post-discharge nutrition on childhood cognition.

Methods

Preterm-born children were randomized at ~36 weeks corrected age (CGA) to either preterm formula (PTF) or term formula (TF) until 6 months, or PTF until 40 weeks CGA, then TF until 6 months (crossover group). Childhood cognition was assessed using the short form Wechsler Intelligence Scale for Children III, allowing computation of full-scale intelligence quotient (FSIQ) and four-factor index scores; verbal comprehension, freedom from distractibility (FDI), perceptual organization (POI), and processing speed (PSI).

Results

Ninety-two children were recruited (mean 10.1 years). FSIQ did not differ by group. PTF-fed children had 10-point higher PSI (p = 0.03) compared to crossover. Faster weight gain from term to 12 weeks CGA was associated with 5-point higher FSIQ (p = 0.02) and four-point higher POI (p = 0.04). Infant head growth was positively associated with FSIQ (+3.8 points,p = 0.04) and FDI (+6 points,p = 0.003).

Conclusions

While there is no long-term impact of post-discharge macronutrient enrichment on childhood cognition, greater weight and head growth in specific epochs is associated with better outcomes. Further studies are needed to determine optimal early diet in preterm infants.

Impact

Achieving adequate nutrient intakes in preterm infants before and after hospital discharge is challenging.

Nutrient intakes prior to discharge affect later cognitive and metabolic outcomes.

Follow-up of a randomized controlled trial shows no cognitive benefit in later childhood from a more nutrient-dense formula compared to standard formula after hospital discharge.

Growth in the first year of life is strongly correlated with childhood cognition and emphasizes the importance of nutrition in early life.
Contribution of horizontal gene transfer to the functionality of microbial biofilm on a macroalgae
Authors: Song Weizhi , Wemheuer Bernd , Steinberg Peter D , Marzinelli Ezequiel M , Thomas Torsten
Published: February 2021

Horizontal gene transfer (HGT) is thought to be an important driving force for microbial evolution and niche adaptation and has been show in vitro to occur frequently in biofilm communities. However, the extent to which HGT takes place and what functions are being transferred in more complex and natural biofilm systems remains largely unknown. To address this issue, we investigated here HGT and enrichment of gene functions in the biofilm community of the common kelp (macroalgae) Ecklonia radiata in comparison to microbial communities in the surrounding seawater. We found that HGTs in the macroalgal biofilms were dominated by transfers between bacterial members of the same class or order and frequently involved genes for nutrient transport, sugar and phlorotannin degradation as well as stress responses, all functions that would be considered beneficial for bacteria living in this particular niche. HGT did not appear to be driven by mobile gene elements, indicating rather an involvement of unspecific DNA uptake (e.g. natural transformation). There was also a low overlap between the gene functions subject to HGT and those enriched in the biofilm community in comparison to planktonic community members. This indicates that much of the functionality required for bacteria to live in an E. radiata biofilm might be derived from vertical or environmental transmissions of symbionts. This study enhances our understanding of the relative role of evolutionary and ecological processes in driving community assembly and genomic diversity of biofilm communities.
Intracellular bacteria are common and taxonomically diverse in cultured and in hospite algal endosymbionts of coral reefs
Authors: Maire Justin , Girvan Sam K , Barkla Sophie E , Perez-Gonzalez Alexis , Suggett David J , Blackall Linda L , van Oppen Madeleine J H
Published: February 2021

Corals house a variety of microorganisms which they depend on for their survival, including endosymbiotic dinoflagellates (Symbiodiniaceae) and bacteria. While cnidarian–microorganism interactions are widely studied, Symbiodiniaceae–bacteria interactions are only just beginning to receive attention. Here, we describe the localization and composition of the bacterial communities associated with cultures of 11 Symbiodiniaceae strains from nine species and six genera. Three-dimensional confocal laser scanning and electron microscopy revealed bacteria are present inside the Symbiodiniaceae cells as well as closely associated with their external cell surface. Bacterial pure cultures and 16S rRNA gene metabarcoding from Symbiodiniaceae cultures highlighted distinct and highly diverse bacterial communities occur intracellularly, closely associated with the Symbiodiniaceae outer cell surface and loosely associated (i.e., in the surrounding culture media). The intracellular bacteria are highly conserved across Symbiodiniaceae species, suggesting they may be involved in Symbiodiniaceae physiology. Our findings provide unique new insights into the biology of Symbiodiniaceae.
Spatial patterns in phage-Rhizobium coevolutionary interactions across regions of common bean domestication
Authors: Van Cauwenberghe Jannick , Santamaría Rosa I , Bustos Patricia , Juárez Soledad , Ducci Maria Antonella , Figueroa Fleming Trinidad , Etcheverry Angela Virginia , González Víctor
Published: February 2021

Bacteriophages play significant roles in the composition, diversity, and evolution of bacterial communities. Despite their importance, it remains unclear how phage diversity and phage-host interactions are spatially structured. Local adaptation may play a key role. Nitrogen-fixing symbiotic bacteria, known as rhizobia, have been shown to locally adapt to domesticated common bean at its Mesoamerican and Andean sites of origin. This may affect phage-rhizobium interactions. However, knowledge about the diversity and coevolution of phages with their respective Rhizobium populations is lacking. Here, through the study of four phage-Rhizobium communities in Mexico and Argentina, we show that both phage and host diversity is spatially structured. Cross-infection experiments demonstrated that phage infection rates were higher overall in sympatric rhizobia than in allopatric rhizobia except for one Argentinean community, indicating phage local adaptation and host maladaptation. Phage-host interactions were shaped by the genetic identity and geographic origin of both the phage and the host. The phages ranged from specialists to generalists, revealing a nested network of interactions. Our results suggest a key role of local adaptation to resident host bacterial communities in shaping the phage genetic and phenotypic composition, following a similar spatial pattern of diversity and coevolution to that in the host.
p53 dynamics vary between tissues and are linked with radiation sensitivity
Authors: Stewart-Ornstein Jacob , Iwamoto Yoshiko , Miller Miles A. , Prytyskach Mark A. , Ferretti Stephane , Holzer Philipp , Kallen Joerg , Furet Pascal , Jambhekar Ashwini , Forrester William C. , Weissleder Ralph , Lahav Galit
Published: February 2021

Radiation sensitivity varies greatly between tissues. The transcription factor p53 mediates the response to radiation; however, the abundance of p53 protein does not correlate well with the extent of radiosensitivity across tissues. Given recent studies showing that the temporal dynamics of p53 influence the fate of cultured cells in response to irradiation, we set out to determine the dynamic behavior of p53 and its impact on radiation sensitivity in vivo. We find that radiosensitive tissues show prolonged p53 signaling after radiation, while more resistant tissues show transient p53 activation. Sustaining p53 using a small molecule (NMI801) that inhibits Mdm2, a negative regulator of p53, reduced viability in cell culture and suppressed tumor growth. Our work proposes a mechanism for the control of radiation sensitivity and suggests tools to alter the dynamics of p53 to enhance tumor clearance. Similar approaches can be used to enhance killing of cancer cells or reduce toxicity in normal tissues following genotoxic therapies.
Colloidal CdSe nanocrystals are inherently defective
Authors: Goldzak Tamar , McIsaac Alexandra R. , Van Voorhis Troy
Published: February 2021

Colloidal CdSe nanocrystals (NCs) have shown promise in applications ranging from LED displays to medical imaging. Their unique photophysics depend sensitively on the presence or absence of surface defects. Using simulations, we show that CdSe NCs are inherently defective; even for stoichiometric NCs with perfect ligand passivation and no vacancies or defects, we still observe that the low energy spectrum is dominated by dark, surface-associated excitations, which are more numerous in larger NCs. Surface structure analysis shows that the majority of these states involve holes that are localized on two-coordinate Se atoms. As chalcogenide atoms are not passivated by any Lewis base ligand, varying the ligand should not dramatically change the number of dark states, which we confirm by simulating three passivation schemes. Our results have significant implications for understanding CdSe NC photophysics, and suggest that photochemistry and short-range photoinduced charge transfer should be much more facile than previously anticipated.
Lasting antibody and T cell responses to SARS-CoV-2 in COVID-19 patients three months after infection
Authors: Jiang Xiao-Lin , Wang Guo-Lin , Zhao Xiang-Na , Yan Fei-Hu , Yao Lin , Kou Zeng-Qiang , Ji Sheng-Xiang , Zhang Xiao-Li , Li Cun-Bao , Duan Li-Jun , Li Yan , Zhang Yu-Wen , Duan Qing , Wang Tie-Cheng , Li En-Tao , Wei Xiao , Wang Qing-Yang , Wang Xue-Feng , Sun Wei-Yang , Gao Yu-Wei , Kang Dian-Min , Zhang Ji-Yan , Ma Mai-Juan
Published: February 2021

The dynamics, duration, and nature of immunity produced during SARS-CoV-2 infection are still unclear. Here, we longitudinally measured virus-neutralising antibody, specific antibodies against the spike (S) protein, receptor-binding domain (RBD), and the nucleoprotein (N) of SARS-CoV-2, as well as T cell responses, in 25 SARS-CoV-2-infected patients up to 121 days post-symptom onset (PSO). All patients seroconvert for IgG against N, S, or RBD, as well as IgM against RBD, and produce neutralising antibodies (NAb) by 14 days PSO, with the peak levels attained by 15–30 days PSO. Anti-SARS-CoV-2 IgG and NAb remain detectable and relatively stable 3–4 months PSO, whereas IgM antibody rapidly decay. Approximately 65% of patients have detectable SARS-CoV-2-specific CD4+ or CD8+ T cell responses 3–4 months PSO. Our results thus provide critical evidence that IgG, NAb, and T cell responses persist in the majority of patients for at least 3–4 months after infection.
Melting and density of MgSiO3 determined by shock compression of bridgmanite to 1254GPa
Authors: Fei Yingwei , Seagle Christopher T. , Townsend Joshua P. , McCoy Chad A. , Boujibar Asmaa , Driscoll Peter , Shulenburger Luke , Furnish Michael D.
Published: February 2021

The essential data for interior and thermal evolution models of the Earth and super-Earths are the density and melting of mantle silicate under extreme conditions. Here, we report an unprecedently high melting temperature of MgSiO3at 500 GPa by direct shockwave loading of pre-synthesized dense MgSiO3(bridgmanite) using the Z Pulsed Power Facility. We also present the first high-precision density data of crystalline MgSiO3to 422 GPa and 7200 K and of silicate melt to 1254 GPa. The experimental density measurements support our density functional theory based molecular dynamics calculations, providing benchmarks for theoretical calculations under extreme conditions. The excellent agreement between experiment and theory provides a reliable reference density profile for super-Earth mantles. Furthermore, the observed upper bound of melting temperature, 9430 K at 500 GPa, provides a critical constraint on the accretion energy required to melt the mantle and the prospect of driving a dynamo in massive rocky planets.
L1 retrotransposons exploit RNA m6A modification as an evolutionary driving force
Authors: Hwang Sung-Yeon , Jung Hyunchul , Mun Seyoung , Lee Sungwon , Park Kiwon , Baek S. Chan , Moon Hyungseok C. , Kim Hyewon , Kim Baekgyu , Choi Yongkuk , Go Young-Hyun , Tang Wanxiangfu , Choi Jongsu , Choi Jung Kyoon , Cha Hyuk-Jin , Park Hye Yoon , Liang Ping , Kim V. Narry , Han Kyudong , Ahn Kwangseog
Published: February 2021

L1 retrotransposons can pose a threat to genome integrity. The host has evolved to restrict L1 replication. However, mechanisms underlying L1 propagation out of the host surveillance remains unclear. Here, we propose an evolutionary survival strategy of L1, which exploits RNA m6A modification. We discover that m6A ‘writer’ METTL3 facilitates L1 retrotransposition, whereas m6A ‘eraser’ ALKBH5 suppresses it. The essential m6A cluster that is located on L1 5′ UTR serves as a docking site for eukaryotic initiation factor 3 (eIF3), enhances translational efficiency and promotes the formation of L1 ribonucleoprotein. Furthermore, through the comparative analysis of human- and primate-specific L1 lineages, we find that the most functional m6A motif-containing L1s have been positively selected and became a distinctive feature of evolutionarily young L1s. Thus, our findings demonstrate that L1 retrotransposons hijack the RNA m6A modification system for their successful replication.
Transcriptome and translatome of CO2 fixing acetogens under heterotrophic and autotrophic conditions
Authors: Song Yoseb , Bae Jiyun , Shin Jongoh , Jin Sangrak , Lee Jung-Kul , Kim Sun Chang , Cho Suhyung , Cho Byung-Kwan
Published: February 2021

Acetogens are anaerobic bacteria that utilise gaseous feedstocks such as carbon monoxide (CO) and carbon dioxide (CO2) to synthesise biomass and various metabolites via the energetically efficient Wood-Ljungdahl pathway. Because of this pathway, acetogens have been considered as a novel platform to produce biochemicals from gaseous feedstocks, potentially replacing the conventional thermochemical processes. Despite their advantages, a lack of systematic understanding of the transcriptional and translational regulation in acetogens during autotrophic growth limits the rational strain design to produce the desired products. To overcome this problem, we presented RNA sequencing and ribosome profiling data of four acetogens cultivated under heterotrophic and autotrophic conditions, providing data on genome-scale transcriptional and translational responses of acetogens during CO2 fixation. These data facilitate the discovery of regulatory elements embedded in their genomes, which could be utilised to engineer strains to achieve better growth and productivity. We anticipate that these data will expand our understanding of the processes of CO2 fixation and will help in the designing of strains for the desired biochemical production.
Effects of Al substitution by Si in Ti3AlC2 nanolaminate
Authors: Hadi M. A. , Roknuzzaman Md , Nasir M. T. , Monira U. , Naqib S. H. , Chroneos A. , Islam A. K. M. A. , Alarco Jose A. , Ostrikov Kostya
Published: February 2021

Recently, a series of high-purity Ti3(Al1−xSix)C2 solid solutions with new compositions (x = 0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) have been reported with interesting mechanical properties. Here, we have employed density functional theory for Ti3(Al1−xSix)C2 solid solutions to calculate a wider range of physical properties including structural, electronic, mechanical, thermal and optical. With the increase of x, a decrease of cell parameters is observed. All elastic constants and moduli increase with x. The Fermi level gradually increases, moving towards and past the upper bound of the pseudogap, when the value of x goes from zero to unity, indicating that the structural stability reduces gradually when the amount of Si increases within the Ti3(Al1−xSix)C2 system. In view of Cauchy pressure, Pugh’s ratio and Poisson’s ratio all compositions of Ti3(Al1−xSix)C2 are brittle in nature. Comparatively, low Debye temperature, lattice thermal conductivity and minimum thermal conductivity of Ti3AlC2 favor it to be a thermal barrier coating material. High melting temperatures implies that the solid solutions Ti3(Al1−xSix)C2 may have potential applications in harsh environments. In the visible region (1.8–3.1 eV), the minimum reflectivity of all compositions for both polarizations is above 45%, which makes them potential coating materials for solar heating reduction.
Contribution of green organs to grain weight in dryland wheat from the 1940s to the 2010s in Shaanxi Province, China
Authors: Sun Yingying , Zhang Suiqi , Yan Jiakun
Published: February 2021

Eight dryland winter wheat cultivars (Triticum aestivum L.), which were widely cultivated from the 1940s to the 2010s in Shaanxi Province, China, were selected and grown in plots, and two water treatments (irrigation and drought) were used to identify the contribution of ears, leaves and stems to grain weight and grain number associated with cultivar replacement. The plant height and stem dry weight of the dryland wheat decreased significantly during the cultivar replacement process, but there was a remarkable increase in the dry matter translocation of stems under irrigation. Shaded-ear and defoliation treatment could decrease the grain number and grain weight, and the grain weight was more influenced. Both the leaf and ear are important photosynthetic sources for dryland wheat, and the contribution of ear assimilates showed a significant increase over time; however, the contribution of leaf assimilates showed a negative correlation with cultivation over time. The accumulation of stem assimilates and ear photosynthesis both increased the grain weight potential. In the future breeding process, cultivars with more assimilates stored in the stem and greater assimilative capacity of ears, especially a greater contribution of ear assimilates, are expected to increase the grain yield.
Using blood data for the differential diagnosis and prognosis of motor neuron diseases: a new dataset for machine learning applications
Authors: Greco Alberto , Chiesa Maria Rosa , Da Prato Ilaria , Romanelli Anna Maria , Dolciotti Cristina , Cavallini Gabriella , Masciandaro Silvia Maria , Scilingo Enzo Pasquale , Del Carratore Renata , Bongioanni Paolo
Published: February 2021

Early differential diagnosis of several motor neuron diseases (MNDs) is extremely challenging due to the high number of overlapped symptoms. The routine clinical practice is based on clinical history and examination, usually accompanied by electrophysiological tests. However, although previous studies have demonstrated the involvement of altered metabolic pathways, biomarker-based monitoring tools are still far from being applied. In this study, we aim at characterizing and discriminating patients with involvement of both upper and lower motor neurons (i.e., amyotrophic lateral sclerosis (ALS) patients) from those with selective involvement of the lower motor neuron (LMND), by using blood data exclusively. To this end, in the last ten years, we built a database including 692 blood data and related clinical observations from 55 ALS and LMND patients. Each blood sample was described by 108 analytes. Starting from this outstanding number of features, we performed a characterization of the two groups of patients through statistical and classification analyses of blood data. Specifically, we implemented a support vector machine with recursive feature elimination (SVM-RFE) to automatically diagnose each patient into the ALS or LMND groups and to recognize whether they had a fast or slow disease progression. The classification strategy through the RFE algorithm also allowed us to reveal the most informative subset of blood analytes including novel potential biomarkers of MNDs. Our results show that we successfully devised subject-independent classifiers for the differential diagnosis and prognosis of ALS and LMND with remarkable average accuracy (up to 94%), using blood data exclusively.