bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination and Persistence: Building the African American Teacher Corps through Summer and Intermittent Teaching, 1860s-1890s
Authors: Fultz Michael
Published: February 2021

This paper explores trends in summer and intermittent teaching practices among African American students in the post-Civil War South, focusing on student activities in the field, the institutions they attended, and the communities they served. Transitioning out of the restrictions and impoverishment of slavery while simultaneously seeking to support themselves and others was an arduous and tenuous process. How could African American youth and young adults obtain the advanced education they sought while sustaining themselves in the process? Individual and family resources were limited for most, while ambitions, both personal and racial, loomed large. Teaching, widely recognized as a means to racial uplift, was the future occupation of choice for many of these students.
RECURSIVE AXIOMATISATIONS FROM SEPARATION PROPERTIES
Authors: EGROT ROB
Published: February 2021

We define a fragment of monadic infinitary second-order logic corresponding to an abstract separation property. We use this to define the concept of a separation subclass. We use model theoretic techniques and games to show that separation subclasses whose axiomatisations are recursively enumerable in our second-order fragment can also be recursively axiomatised in their original first-order language. We pin down the expressive power of this formalism with respect to first-order logic, and investigate some questions relating to decidability and computational complexity. As applications of these results, by showing that certain classes can be straightforwardly defined as separation subclasses, we obtain first-order axiomatisability results for these classes. In particular we apply this technique to graph colourings and a class of partial algebras arising from separation logic.
Politics, International Banking, and the Debt Crisis of 1982
Authors: Altamura Carlo Edoardo , Zendejas Juan Flores
Published: February 2021

How does politics affect private international lending? This article highlights the relationship between international banks, their home governments, the International Monetary Fund (IMF), and international regulators during the years that preceded the debt crisis of 1982. Based on new archival evidence from different case studies, we find that the decisions of commercial banks to lend were largely based on the home governments’ preferences, competition, and the assumption that home governments and international organizations would provide lender of last resort functions to support borrowing governments. While previous works suggest the 1982 debt crisis was unexpected, we show that banks primarily reacted to the deteriorating macroeconomic situation in many emerging economies once the support of their home governments and the IMF became uncertain.
Partners, Servants, or Entrepreneurs? Banians in the Nineteenth-Century Bengal Economy
Authors: Aldous Michael
Published: February 2021

Banians acted as intermediaries for European merchants in Bengal. They were highly influential in the eighteenth century but their importance waned thereafter. This article reexamines their role in the nineteenth century and argues that their importance persisted but evolved in response to changes in the Bengal economy and issues of contracting and governance. It shows that the banians remained a nexus between the local and global economies, facilitating a bidirectional transfer of knowledge. They enabled the development of innovative Indian business forms and contributed to the emergence of a diverse ecology of organizational forms and ownership in Bengal at the end of the nineteenth century.
The Sky above and the Mud below: Two Books about Steve Jobs
Authors: Tedlow Richard S.
Published: February 2021

Steve Jobs was the most charismatic businessperson in the modern era. When he died, on October 5, 2011, Apple was inundated with condolence messages from all over the United States and from around the world. These notes were sent not only to Apple headquarters in Cupertino, California, but to Apple retail stores. The stores posted them on their windows. In addition, bouquets of flowers were brought to the stores. Think of this—flowers in front of hundreds of stores in dozens of countries because of Jobs's death. No one knows how many notes were received at Apple and in the stores. According to the “Remembering Steve” page on Apple.com, “Over a million people from all over the world have shared their memories, thoughts, and feelings about Steve.” As he was dying, people made a pilgrimage to his home in Palo Alto. His daughter has written that “a few people he didn’t know came to the doors wanting to see him … , wandering into the garden. … A stranger in a sari begged to talk with him. A man came in through the gate and said he had flown in from Bulgaria just to see my father.” After Jobs's death, California governor Jerry Brown declared October 16 to be “Steve Jobs Day.” The president of United States and the First Lady, Barack and Michelle Obama, posted a condolence note. Nothing remotely like this outpouring had ever taken place on the occasion of the death of an American CEO.
Training Leaders to Win Wars and Forge Peace: Lessons from History
Authors: Tufano Peter
Published: February 2021

Leaders of business schools and other educational institutions have enjoyed decades of stability. Today, we confront a set of systemic global challenges, including a pandemic, severe economic weakness, heightened inequality, racial injustice, and a climate emergency. Taken together, these challenges redefine the environment in which we operate—and offer us an opportunity to reimagine our organizations. We can learn about how to deal with this level of upheaval by studying how leading U.S. business schools responded to World War II. All shrank as students and faculty were drafted, most innovated in fairly traditional ways while still maintaining existing activities alongside of war-time innovations, and some pushed forward long-standing institutional change. One school choose a different path, shutting all peacetime programs as it fully committed not only to helping win a global war but, just as importantly, to forging a lasting peace—the long-term economic prosperity that followed the war. The lessons we can draw from academic leaders from nearly eighty years ago are apt today.
Do patients report quality of life improvements after fitting of their unilateral bone conducting hearing implant?
Authors: Meghji S , Collett A , Nunney I , Prinsley P , Hanif J
Published: February 2021

Objective

The audiological benefits of a bone conducting hearing implant are well documented; however, there is a paucity of literature comparing pre- and post-operative quality of life benefits. This study assessed the quality of life status before and after the device is implanted.

Methods

A prospective study was conducted of all adult bone conducting hearing implants inserted in a teaching hospital between 2012 and 2017. All patients completed the Glasgow Health Status Inventory, a validated quality of life questionnaire, before and three to six months after implantation.

Results

Sixty-two patients received a unilateral bone conducting hearing implant. All scores except the social score improved post-operatively. The paired t-test showed that the differences in the means for the Glasgow Health Status Inventory total, general and physical scores were statistically significant at the 5 per cent level (p < 0.0001).

Conclusion

This study, one of the few to assess quality of life pre- and post-implantation, showed a vast improvement in patients’ perceived quality of life from the pre- to the post-operative phase.
Presence through absence? Understanding the role of capital in the African Human Rights Action Plan
Authors: Okafor Obiora Chinedu , Ahmed Sanaa , Bawa Sylvia , Odumosu-Ayanu Ibironke
Published: February 2021

This study examines the African Human Rights Action Plan (AHRAP) through the lens of Upendra Baxi's germinal theory on the emergence in our time of a ‘trade-related, market-friendly human rights’ (TREMF) thesis that is challenging the specific understandings of ‘people-centric’ human rights that are predicated in the letter and spirit of the Universal Declaration of Human Rights (UDH). Baxi contends, instead, that the dominant strands of the contemporary understandings of human rights are – for the most part – designed to protect the interests of global capital. That said, human rights frameworks in low-income countries need to be studied with a view to what they say and don't say about global capital. Despite its attempt to facilitate a progressive realisation of human rights in Africa, the AHRAP does not rise far enough above the TREMF paradigm to re-locate itself within the UDH one. This is due to the AHRAP not adequately theorising and analysing the role of capital in the (non)realisation of human rights in Africa. By allowing trade and market practices to slip to a significant extent beyond its purview, the AHRAP privileges – to a significant degree – the needs/interests of capital over the human rights of ordinary Africans. That is, the victims of the excesses of capital in Africa are reincarnated in the AHRAP document by the fact of their exclusion from it.
Coulomb collisions in strongly anisotropic plasmas I. Cyclotron cooling in electron–ion plasmas
Authors: Kennedy D. , Helander P.
Published: February 2021

The behaviour of a collisional plasma that is optically thin to cyclotron radiation is considered, and the distribution functions accessible to it on the various time scales in the system are calculated. Particular attention is paid to the limit in which the collision time exceeds the radiation emission time, making the electron distribution function strongly anisotropic. Unusually for plasma physics, the collision operator can nevertheless be calculated analytically although the plasma is far from Maxwellian. The rate of radiation emission is calculated and found to be governed by the collision frequency multiplied by a factor that only depends logarithmically on plasma parameters.
A Parametric Study of Compliant Link Design for Safe Physical Human–Robot Interaction
Authors: She Yu , Song Siyang , Su Hai-jun , Wang Junmin
Published: February 2021

Robots of next-generation physically interact with the world rather than be caged in a controlled area, and they need to make contact with the open-ended environment to perform their task. Compliant robot links offer intrinsic mechanical compliance for addressing the safety issue for physical human–robot interactions (pHRI). However, many important research questions are yet to be answered. For instance, how do system parameters, for example, mechanical compliance, motor torque, impact velocities, and so on, affect the impact force? how to formulate system impact dynamics of compliant robots, and how to size their geometric dimensions to maximize impact force reduction. In this paper, we present a parametric study of compliant link (CL) design for safe pHRI. We first present a theoretical model of the pHRI system that is comprised of robot dynamics, an impact contact model, and dummy head dynamics. After experimentally validating the theoretical model, we then systematically study the effects of CL parameters on the impact force in more detail. Specifically, we explore how the design and actuation parameters affect the impact force of pHRI system. Based on the parametric studies of the CL design, we propose a step-by-step process and a list of concrete guidelines for designing CL with safety constraints in pHRI. We further conduct a simulation case study to validate this design process and design guidelines.
Forward Kinematic Modeling of Conical-Shaped Continuum Manipulators
Authors: Bouyom Boutchouang A. H. , Melingui Achille , Mvogo Ahanda J. J. B. , Lakhal Othman , Biya Motto Frederic , Merzouki Rochdi
Published: February 2021

Forward kinematics is essential in robot control. Its resolution remains a challenge for continuum manipulators because of their inherent flexibility. Learning-based approaches allow obtaining accurate models. However, they suffer from the explosion of the learning database that wears down the manipulator during data collection. This paper proposes an approach that combines the model and learning-based approaches. The learning database is derived from analytical equations to prevent the robot from operating for long periods. The database obtained is handled using Deep Neural Networks (DNNs). The Compact Bionic Handling robot serves as an experimental platform. The comparison with existing approaches gives satisfaction.
Studying National Commemoration and Political Celebrations in Africa: The Online Archive African Independence Days
Authors: Gabriel Marie-Christin , Lentz Carola
Published: February 2021

The Department of Anthropology and African Studies (ifeas) at Johannes Gutenberg University Mainz hosts a comprehensive archive on African Independence Day celebrations. Created in 2010, the archive is one of the outcomes of a large comparative research project on African national days directed by Carola Lentz. It offers unique insights into practices of as well as debates on national commemoration and political celebrations in Africa. The archive holds more than 28,000 images, including photographs, newspaper articles, documents, and objects from twelve African countries: Benin, Burkina Faso, Cameroon, Côte d'Ivoire, Democratic Republic of the Congo, Gabon, Ghana, Madagascar, Mali, Namibia, Nigeria, and Tanzania. It primarily consists of an online photo and newspaper archive (https://bildarchiv.uni-mainz.de/AUJ/; https://www.blogs.uni-mainz.de/fb07-ifeas-eng/departmental-archives/online-archive-african-independence-days/); some of the material is also stored in the physical archive on African Independence Days at ifeas as well as in the department's ethnographic collection (https://www.blogs.uni-mainz.de/fb07-ifeas-eng/ethnographic-collection/). Most of the material concerns recent celebrations, but the collection has been complemented by some documentation of earlier festivities. Archives hold many stories while they also have a story to tell in their own right. This article discusses both aspects. It first traces the history of the Online Archive African Independence Days at ifeas. It then provides an overview of the different categories of material stored in the archive and tells a few of the many stories that the photos, texts and objects contain. We hope to demonstrate that the archive holds a wealth of sources that can be mined for studies on national commemoration and political celebrations in Africa, and, more generally, on practices and processes of nation-building and state-making.
India, Racial Caste, and Abolition in Charles Sumner's Political Thought
Authors: Ramesh Hari
Published: February 2021

In recent years, scholars across the humanities have argued that the nineteenth-century American abolitionists articulated important conceptual lessons about democracy. This essay contributes to this literature by newly interpreting the political thought of Charles Sumner. Regnant scholarly treatments of Sumner have been narrowly biographical. I shift focus by examining his use of the word “caste” as an analytic and political term. The article demonstrates that Sumner adopted the language of caste from missionary accounts of caste hierarchy in India; that he used this information to argue that there was an oppressive analogue at home: racial caste; and that, accordingly, Sumner's conception of abolition included the dismantling of racial caste and the cultivation of interracial republican association.
A Positive Zonal Wind Feedback on Sudden Stratospheric Warming Development Revealed by CESM2 (WACCM6) Reforecasts
Authors: Davis Nicholas A. , Richter Jadwiga H. , Edwards Jim , Glanville Anne A.
Published: February 2021

Sudden stratospheric warmings (SSWs) are an extreme weather event with impacts on the ionosphere and on tropospheric weather and predictability. The mechanisms governing their formation remain elusive, despite their deterministic predictability at nearly 2 weeks. This study uses high resolution CESM2 (WACCM6) subseasonal reforecasts to examine the dynamics that differentiate successful and unsuccessful SSW predictions. Successful reforecasts are generally initialized with a weaker stratospheric jet. However, the basic relationships between jet deceleration, wave drag, and the residual mean angular momentum flux do not fundamentally differ between successful and unsuccessful reforecasts. Instead, the projection of the residual circulation onto a weakened jet produces a weaker angular momentum flux, which leads to a more rapid erosion of the jet as the residual circulation cannot effectively balance the sustained wave drag. This information could be used to develop forecasting practices that could probe the likelihood of SSWs at longer timescales.
Reconciling the Size‐Dependence of Marine Particle Sinking Speed
Authors: Cael B. B. , Cavan Emma L. , Britten Gregory L.
Published: February 2021

Sinking particles are critical to the ocean's “biological pump,” sequestering carbon from the atmosphere. Particles' sinking speeds are a primary factor determining fluxes and subsequent ecological and climatic impacts. While size is a key determinant of particles' sinking speeds, observations suggest a variable size‐sinking relationship, affected by other particle properties, resulting in substantial spread in parameterizations of particle sinking and fluxes. We compile particle size‐sinking observations and apply hierarchical Bayesian statistical models to resolve the size‐sinking relationship while accounting for other factors. We find an overall scaling close to the general Navier‐Stokes drag equation, and differences between particle types, open ocean versus coastal/laboratory particles, and in situ versus ex situ methods. These results can help harmonize how Earth system models parameterize particle fluxes and support a weaker size‐dependence than often assumed, with implications for the flux contribution of small particles and the predicted future shrinking of marine particle populations.
An Explanation for Arecibo Plasma Line Power Striations
Authors: Longley William J. , Vierinen Juha , Sulzer Michael P. , Varney Roger H. , Erickson Philip J. , Perillat Phil
Published: February 2021

Measurements of plasma lines by the Arecibo incoherent scatter radar are known to have sharp striations in power, varying with the plasma frequency and magnetic aspect angle of the radar beam. We explain these power striations as the manifestation of a suprathermal electron population with peaks in energy at approximately 15, 25, and 45 eV. These energies correspond to sharp features in the photoelectron energy spectra measured by rockets and spacecraft. A new theory is developed to predict the plasma line power for an arbitrary, magnetized suprathermal distribution. The magnetization terms in this theory are shown to contribute substantially to the enhancement of plasma line power through inverse Landau and cyclotron damping of the suprathermal peaks. The theory is applied as a forward model to measurements obtained at Arecibo for different magnetic field aspect angles, showing general agreement with the data. At large magnetic aspect angles the theory reproduces the upper‐hybrid instability which can cause 150 km echoes. The developed theory allows for the suprathermal distribution at a given altitude to be probed across a wide range of energies and pitch angles.
One and a Half Million Yearlong Aridity During the Middle Eocene in North‐West China Linked to a Global Cooling Episode
Authors: Zhang Rui , Kravchinsky Vadim A. , Qin Jie , Goguitchaichvili Avto , Li Jianxing
Published: February 2021

The Eocene record of substantial aridification near Tibet was reported to mimic the global climate cooling trend, overwriting the previously proposed dominant role of the Tibetan Plateau uplift in the aridification (Li et al., 2018, https://doi.org/10.1038/s41467‐018‐05415‐x). Here we present new paleoclimate data from the red clay sequence deposited between 40 and 50 Ma in Altun Shan at the northeastern edge of the Tibetan Plateau. After building an age model using a compilation of magnetostratigraphy and cyclostratigraphy, we demonstrate that our record of magnetic susceptibility in the Altun Shan red clay exhibits variations linked to eccentricity cycles. Our age model allows us to estimate the age of eight short geomagnetic events, cryprochrons, in Altun Shan. Further we show that the aridification interval in Altun Shan coincides with (i) a cooling event recorded in the global oxygen isotope record, (ii) a sea surface temperature record on the east Tasmanian plateau, and (iii) an aridity record in the surrounding sedimentary basins of Central Asia. The middle Eocene aridity and cooling reached its maximum 45.5‐44 Ma.
The Kinetics of O2 Singlet Electronic States in the Upper and Middle Atmosphere During Energetic Electron Precipitation
Authors: Kirillov A. S. , Belakhovsky V. B.
Published: February 2021

The electronic kinetics of O2 singlet states a1Δg and b1 in the upper and middle atmosphere of the Earth during energetic electron precipitation is considered. Intramolecular and intermolecular electron energy transfers in inelastic collisions of electronically excited molecular oxygen and molecular nitrogen with O2 and N2 molecules are taken into account in the calculations. The calculations indicate an influence of atmospheric density increase on the calculated volume intensity of 762 nm emission. For the first time, it is shown the dependence of the calculated column intensity ratios of 1.27 μm and 762 nm bands on the energy of auroral and relativistic electrons (40 keV to 10 MeV) and on time of the precipitation. Applying the calculated integral intensities of the bands, we have calculated column intensities of 762 nm and 1.27 μm bands for 12 most intensive events of energetic electron precipitations observed in the polar atmosphere during 2003–2014.
Permafrost Organic Carbon Turnover and Export Into a High‐Arctic Fjord: A Case Study From Svalbard Using Compound‐specific 14C Analysis
Authors: Kusch Stephanie , Rethemeyer Janet , Ransby Daniela , Mollenhauer Gesine
Published: February 2021

In a warming climate, thawing permafrost soils in the circumpolar Arctic region are subject to enhanced microbial turnover as well as mass mobilization and other erosion processes. High‐Arctic settings such as Svalbard are exceptionally vulnerable to these effects, but the presence of coal deposits obscures the organic carbon (OC) signature of permafrost OC, particularly its carbon isotope composition, when studying OC turnover and export. Here, we analyze the compound‐specific δ13C and Δ14C isotopic composition of alkanoic acids from permafrost soils and river and fjord sediments to assess soil turnover in the catchment of the Bayelva River near Ny‐Ålesund and trace transport and re‐burial of permafrost OC into the adjacent Kongsfjord. Our data confirm the influence of coal‐derived OC on δ13C and Δ14C values of bulk soil and sedimentary OC, while alkanoic acid δ13C and Δ14C values are less affected by coal contributions. Alkanoic acid Δ14C values in the soil profile imply long–term residence in soils prior to deposition in river and fjord sediments, that is, multi‐millennial turnover that is significantly slower than reported from other environments. Strongly 14C‐depleted vascular plant‐derived long‐chain alkanoic acids can be found in Bayelva River and Kongsfjord sediments revealing substantial input of deep active layer/permafrost OC, particularly in the Bayelva River and off its river mouth. In the central Kongsfjord, long‐chain alkanoic acid Δ14C values are higher either reflecting input from other permafrost areas or physical effects resulting, for example, from deposition in settings with different accumulation rates or from sediment sorting.
Simultaneous Drought and Heat Wave Events Are Becoming More Common
Authors: Derouin Sarah
Published: February 2021

As the world heats up, the number and duration of combined stress events are increasing, causing harmful environmental and human impacts.
Prevalence, awareness, treatment and control of young-onset hypertension in Malaysia, 2006–2015
Authors: Khoo Yi Yi , Farid Nik Daliana Nik , Choo Wan Yuen , Omar Azahadi
Published: February 2021

The continuous presence of elevated blood pressure (BP) when young is a strong predictor of future cardiovascular risk. This study aimed to elucidate the prevalence, awareness, treatment and control of young-onset hypertension (YOH) in Malaysia during the period 2006–2015. Data on respondents aged 18–39 diagnosed with YOH according to the 7th Joint National Committee Report (USA) were extracted from three National Health and Morbidity Surveys (2006, 2011, and 2015). The prevalence of YOH remained stable: 17.7%, 95% CI [17.0, 18.3] in 2006, 17.0%, 95% CI [16.0, 17.9] in 2011 and 18.4%, 95% CI [17.4, 19.4] in 2015. Awareness, treatment and control rates were suboptimal; 15% were aware of their diagnosis, of which less than 50% were on treatment and less than 40% who were on treatment had their BP controlled. Trend analysis revealed a significant increase in YOH prevalence among urban dwellers; those with no formal and tertiary education and middle-income earners. YOH awareness and treatment rates were lower among respondents <30 years; however, when treated, this group achieved overall better control rates. Females had higher awareness and treatment rates, but lower control. Treatment rates remained stable for all ethnicities with the exception of Chinese, which decreased. This study narrows the knowledge gap on YOH epidemiology in Malaysia by providing crucial information on the pervasiveness of hypertension among young adults. Results can be used to develop non-communicable disease policies and health promotion strategies specially targeted at young adults who are in the prime of life.
Ferroptosis: mechanisms and links with diseases
Authors: Yan Hong-fa , Zou Ting , Tuo Qing-zhang , Xu Shuo , Li Hua , Belaidi Abdel Ali , Lei Peng
Published: February 2021

Ferroptosis is an iron-dependent cell death, which is different from apoptosis, necrosis, autophagy, and other forms of cell death. The process of ferroptotic cell death is defined by the accumulation of lethal lipid species derived from the peroxidation of lipids, which can be prevented by iron chelators (e.g., deferiprone, deferoxamine) and small lipophilic antioxidants (e.g., ferrostatin, liproxstatin). This review summarizes current knowledge about the regulatory mechanism of ferroptosis and its association with several pathways, including iron, lipid, and cysteine metabolism. We have further discussed the contribution of ferroptosis to the pathogenesis of several diseases such as cancer, ischemia/reperfusion, and various neurodegenerative diseases (e.g., Alzheimer’s disease and Parkinson’s disease), and evaluated the therapeutic applications of ferroptosis inhibitors in clinics.
Statin use is associated with reduced motor recovery after spinal cord injury
Authors: Triplet Erin M. , Scarisbrick Isobel A.
Published: February 2021

Study design

We completed retrospective analysis of statin use in individuals with neurologically significant spinal cord injury in a historical cohort study.

Objective

Our objective was to establish the prevalence of cholesterol-lowering agent use following spinal cord injury (SCI) and to determine the impact on recovery of motor function.

Setting

Patients enrolled in the Rochester Epidemiology Project in Olmsted County, Minnesota, USA from 2005 to 2018 were included in analysis.

Methods

Exclusion criteria: age <18, comorbid neurological disease, prior neurological deficit, nontraumatic injury, survival <1 year, or lack of motor deficit. Demographics and cholesterol-lowering agent use in 83 individuals meeting all criteria were recorded. A total of 68/83 individuals were then assessed for change in function over the first 2 months after injury using the ISNCSCI motor subscore. Statistical comparison between control and statin groups was done by two-sided Chi-squared test or two-tailed Student’s t test. Generalized regression was performed to assess associations between independent variables and functional outcome.

Results

30% of individuals with SCI had a prescription for a cholesterol-lowering agent. No significant differences were observed in severity of injury or demographic composition between groups. The change in motor subscore was reduced in the statin group compared to controls (p = 0.03, Mann–Whitney). Both severity of injury and statin were significant predictors of reduced motor recovery (p = 0.001, and p = 0.04, respectively).

Conclusions

Both severity of SCI and statins were significant predictors of reduced motor recovery. Additional investigation is needed to address potential impact of statin-therapy in the context of CNS injury and repair.
Tan’s two-body contact across the superfluid transition of a planar Bose gas
Authors: Zou Y.-Q. , Bakkali-Hassani B. , Maury C. , Le Cerf É. , Nascimbene S. , Dalibard J. , Beugnon J.
Published: February 2021

Tan’s contact is a quantity that unifies many different properties of a low-temperature gas with short-range interactions, from its momentum distribution to its spatial two-body correlation function. Here, we use a Ramsey interferometric method to realize experimentally the thermodynamic definition of the two-body contact, i.e., the change of the internal energy in a small modification of the scattering length. Our measurements are performed on a uniform two-dimensional Bose gas of 87Rb atoms across the Berezinskii–Kosterlitz–Thouless superfluid transition. They connect well to the theoretical predictions in the limiting cases of a strongly degenerate fluid and of a normal gas. They also provide the variation of this key quantity in the critical region, where further theoretical efforts are needed to account for our findings.
Two-phase transport in a cemented waste package considering spatio-temporal evolution of chemical conditions
Authors: Huang Yonghui , Shao Haibing , Wieland Erich , Kolditz Olaf , Kosakowski Georg
Published: February 2021

The long-term evolution of cemented waste packages is governed by (bio)chemical reactions between waste, cement, and barrier materials, and by transport processes inside the waste package and through openings in the waste package hull. Inside a waste package, gases can be generated by pH-dependent anoxic corrosion of metals and the degradation of organic matter. The (bio)chemical reactions consume water and will not proceed under dry conditions. The degradation of cementitious materials lowers the alkaline pH of the pore water. The modeling of such a complex feedback system shows that the internal structure of a waste package and the exchange of mass with the environment (boundary conditions) are major factors that determine the importance of process couplings. The (bio)chemical reactions are controlled by internal re-distribution of water predominantly via vapor transport. Calculated gas generation rates were found to be affected by dry-out processes inside the drum.
Ubiquitin ligation to F-box protein targets by SCF–RBR E3–E3 super-assembly
Authors: Horn-Ghetko Daniel , Krist David T. , Prabu J. Rajan , Baek Kheewoong , Mulder Monique P. C. , Klügel Maren , Scott Daniel C. , Ovaa Huib , Kleiger Gary , Schulman Brenda A.
Published: February 2021

E3 ligases are typically classified by hallmark domains such as RING and RBR, which are thought to specify unique catalytic mechanisms of ubiquitin transfer to recruited substrates1,2. However, rather than functioning individually, many neddylated cullin–RING E3 ligases (CRLs) and RBR-type E3 ligases in the ARIH family—which together account for nearly half of all ubiquitin ligases in humans—form E3–E3 super-assemblies3–7. Here, by studying CRLs in the SKP1–CUL1–F-box (SCF) family, we show how neddylated SCF ligases and ARIH1 (an RBR-type E3 ligase) co-evolved to ubiquitylate diverse substrates presented on various F-box proteins. We developed activity-based chemical probes that enabled cryo-electron microscopy visualization of steps in E3–E3 ubiquitylation, initiating with ubiquitin linked to the E2 enzyme UBE2L3, then transferred to the catalytic cysteine of ARIH1, and culminating in ubiquitin linkage to a substrate bound to the SCF E3 ligase. The E3–E3 mechanism places the ubiquitin-linked active site of ARIH1 adjacent to substrates bound to F-box proteins (for example, substrates with folded structures or limited length) that are incompatible with previously described conventional RING E3-only mechanisms. The versatile E3–E3 super-assembly may therefore underlie widespread ubiquitylation.
Allergic rhinitis, asthma and laryngopharyngeal reflux disease: a cross-sectional study on their reciprocal relations
Authors: Kakaje Ameer , Alhalabi Mohammad Marwan , Alyousbashi Ayham , Ghareeb Ayham
Published: February 2021

Allergic rhinitis (AR) is a common medical condition worldwide. It is an inflammation in the nasal mucosa due to allergen exposure throughout the year. Laryngopharyngeal reflux (LPR) is another medical condition that can overlap with AR. LPR can be considered an extra oesophageal manifestation of gastro-oesophageal reflux disease (GORD) or a different entity. Its diagnosis imposes a real challenge as it has a wide range of unspecific symptoms. Although AR and LPR are not life-threatening, they can severely affect the quality of life for years and cause substantial distress. Moreover, having AR is associated with having asthma which is also in turn associated with GORD. This is a cross-sectional study which used surveys distributed online on Social Media and targeted people across Syria. All participants who responded to the key questions were included. Reflux symptom index (RSI) was used for LPR, and score for allergic rhinitis (SFAR) was used for AR. Demographic questions and whether the participant had asthma were also included in the survey. We found that there was an association between the symptoms of LPR and AR p < 0.0001 (OR, 2.592; 95% CI 1.846–3.639), and their scores were significantly correlated (r = 0.334). Having asthma was associated with LPR symptoms p = 0.0002 (OR 3.096; 95% CI 1.665–5.759) and AR p < 0.0001 (OR 6.772; 95% CI 2.823–16.248). We concluded that there was a significant association between having LPR, AR, and asthma. We need more studies to distinguish between their common symptoms and aetiologies.
Influenza-associated disease burden in mainland China: a systematic review and meta-analysis
Authors: Li Jing , Chen Yinzi , Wang Xiling , Yu Hongjie
Published: February 2021

Influenza causes substantial morbidity and mortality. Many original studies have been carried out to estimate disease burden of influenza in mainland China, while the full disease burden has not yet been systematically reviewed. We did a systematic review and meta-analysis to assess the burden of influenza-associated mortality, hospitalization, and outpatient visit in mainland China. We searched 3 English and 4 Chinese databases with studies published from 2005 to 2019. Studies reporting population-based rates of mortality, hospitalization, or outpatient visit attributed to seasonal influenza were included in the analysis. Fixed-effects or random-effects model was used to calculate pooled estimates of influenza-associated mortality depending on the degree of heterogeneity. Meta-regression was applied to explore the sources of heterogeneity. Publication bias was assessed by funnel plots and Egger’s test. We identified 30 studies eligible for inclusion with 17, 8, 5 studies reporting mortality, hospitalization, and outpatient visit associated with influenza, respectively. The pooled influenza-associated all-cause mortality rates were 14.33 and 122.79 per 100,000 persons for all ages and ≥ 65 years age groups, respectively. Studies were highly heterogeneous in aspects of age group, cause of death, statistical model, geographic location, and study period, and these factors could explain 60.14% of the heterogeneity in influenza-associated mortality. No significant publication bias existed in estimates of influenza-associated all-cause mortality. Children aged < 5 years were observed with the highest rates of influenza-associated hospitalizations and ILI outpatient visits. People aged ≥ 65 years and < 5 years contribute mostly to mortality and morbidity burden due to influenza, which calls for targeted vaccination policy for older adults and younger children in mainland China.
Water column gradients beneath the summer ice of a High Arctic freshwater lake as indicators of sensitivity to climate change
Authors: Bégin Paschale N. , Tanabe Yukiko , Rautio Milla , Wauthy Maxime , Laurion Isabelle , Uchida Masaki , Culley Alexander I. , Vincent Warwick F.
Published: February 2021

Ice cover persists throughout summer over many lakes at extreme polar latitudes but is likely to become increasingly rare with ongoing climate change. Here we addressed the question of how summer ice-cover affects the underlying water column of Ward Hunt Lake, a freshwater lake in the Canadian High Arctic, with attention to its vertical gradients in limnological properties that would be disrupted by ice loss. Profiling in the deepest part of the lake under thick mid-summer ice revealed a high degree of vertical structure, with gradients in temperature, conductivity and dissolved gases. Dissolved oxygen, nitrous oxide, carbon dioxide and methane rose with depth to concentrations well above air-equilibrium, with oxygen values at > 150% saturation in a mid-water column layer of potential convective mixing. Fatty acid signatures of the seston also varied with depth. Benthic microbial mats were the dominant phototrophs, growing under a dim green light regime controlled by the ice cover, water itself and weakly colored dissolved organic matter that was mostly autochthonous in origin. In this and other polar lakes, future loss of mid-summer ice will completely change many water column properties and benthic light conditions, resulting in a markedly different ecosystem regime.
Reference values of electrographic and cardiac ultrasound parameters in Russian healthy children and adolescents
Authors: Landon Geraldine , Denjoy Isabelle , Clero Enora , Silenok Aleksandr , Kurnosova Irina , Butsenin Andrey , Gourmelon Patrick , Jourdain Jean-Rene
Published: February 2021

Between 2009 and 2013, a large cross-sectional study on the health consequences of the Chernobyl nuclear accident was performed in the contaminated and uncontaminated territories of the Bryansk Oblast (Russian Federation). The objective of this work was to confirm or refute a possible association between childhood cardiac arrhythmia and a chronic exposure to caesium-137. As part of this study, a large number of electrocardiographic and cardiac ultrasound parameters were collected from 18,152 children aged 2–18 years including 12,512 healthy ones not contaminated with caesium-137. It seemed therefore relevant for us to share in a second publication these medical data based on healthy and uncontaminated children with the scientific community because of the large quantities and the limited availability of such kind of data. In the present study, relating to electrocardiographic parameters, the measurements performed fully reflect the expected evolution of the paediatric electrocardiogram between 5 and 18 years of age. Thus, the median values were generally quite close to those available in the literature. In contrast, differences in the 2nd and 98th percentiles were notable and could be explained in particular by the type of equipment used, the number of subjects included in the study and racial disparities. As for echocardiographic parameters, the evolution of the measured values in age groups is consistent with what was expected considering factors such as growth. In comparison with other scientific studies that have investigated these echocardiographic parameters, some differences by age groups have been identified. The ethnic factor truly appears to be a relevant feature to consider. In view of the results, it appeared essential to the authors to approach the methodological conditions of the scientific studies already published on the topic to be truly comparable and thus to provide a reliable answer on a topic for which real expectations in terms of medical care are required.
Quenching effect of oscillating potential on anisotropic resonant transmission through a phosphorene electrostatic barrier
Authors: Biswas R. , Sinha C.
Published: February 2021

The anisotropy in resonant tunneling transport through an electrostatic barrier in monolayer black phosphorus either in presence or in absence of an oscillating potential is studied. Non-perturbative Floquet theory is applied to solve the time dependent problem and the results obtained are discussed thoroughly. The resonance spectra in field free transmission are Lorentzian in nature although the width of the resonance for the barrier along the zigzag (Г–Y) direction is too thinner than that for the armchair (Г–X) one. Resonant transmission is suppressed for both the cases by the application of oscillating potential that produces small oscillations in the transmission around the resonant energy particularly at low frequency range. Sharp asymmetric Fano resonances are noted in the transmission spectrum along the armchair direction while a distinct line shape resonance is noted for the zigzag direction at higher frequency of the oscillating potential. Even after the angular average, the conductance along the Г–X direction retains the characteristic Fano features that could be observed experimentally. The present results are supposed to suggest that the phosphorene electrostatic barrier could be used successfully as switching devices and nano detectors.
Elevated serum TREM-1 is associated with periodontitis and disease activity in rheumatoid arthritis
Authors: Inanc Nevsun , Mumcu Gonca , Can Meryem , Yay Meral , Silbereisen Angelika , Manoil Daniel , Direskeneli Haner , Bostanci Nagihan
Published: February 2021

The triggering receptor expressed on myeloid cells 1 (TREM-1) and peptidoglycan recognition protein 1 (PGLYRP1) are involved in the propagation of inflammatory responses. This study investigated whether serum levels of TREM-1 and PGLYRP1 correlate with periodontitis in rheumatoid arthritis (RA) patients. A total of 154 non-smoking participants with RA (n = 55, F/M: 41/14), Behçet´s disease (BD, n = 41, F/M: 30/11) and healthy controls (HC, n = 58, F/M: 40/18) were recruited. Serum and saliva were collected, the 28-joint disease activity score (DAS-28) was calculated and dental/periodontal measurements were recorded. Serum TREM-1 and PGLYRP1 levels were measured by ELISA and salivary bacterial DNA counts by quantitative polymerase chain reaction. TREM-1 and PGLYRP1 levels were higher in RA (166.3 ± 94.3; 155.5 ± 226.9 pg/ml) than BD (102.3 ± 42.8; 52.5 ± 26.3 pg/ml) and HCs (89.8 ± 55.7; 67.4 ± 37.3 pg/ml) (p < 0.05). In RA, periodontitis was associated with increased TREM-1 and PGLYRP1 levels (p < 0.05), yet in patients under methotrexate TREM-1 levels were lower. TREM-1 correlated with C-reactive protein (CRP) levels, DAS-28 and erythrocyte sedimentation rate, whereas PGLYRP1 positively correlated with CRP. RA patients displayed 3.5-fold higher salivary bacterial DNA counts than HCs. Increased serum TREM-1 levels correlated with PGLYRP1, CRP and DAS-28-ESR in RA patients with periodontitis.
First finding of free-living representatives of Prokinetoplastina and their nuclear and mitochondrial genomes
Authors: Tikhonenkov Denis V. , Gawryluk Ryan M. R. , Mylnikov Alexander P. , Keeling Patrick J.
Published: February 2021

Kinetoplastids are heterotrophic flagellated protists, including important parasites of humans and animals (trypanosomatids), and ecologically important free-living bacterial consumers (bodonids). Phylogenies have shown that the earliest-branching kinetoplastids are all parasites or obligate endosymbionts, whose highly-derived state makes reconstructing the ancestral state of the group challenging. We have isolated new strains of unusual free-living flagellates that molecular phylogeny shows to be most closely related to endosymbiotic and parasitic Perkinsela and Ichthyobodo species that, together with unidentified environmental sequences, form the clade at the base of kinetoplastids. These strains are therefore the first described free-living prokinetoplastids, and potentially very informative in understanding the evolution and ancestral states of morphological and molecular characteristics described in other kinetoplastids. Overall, we find that these organisms morphologically and ultrastructurally resemble some free-living bodonids and diplonemids, and possess nuclear genomes with few introns, polycistronic mRNA expression, high coding density, and derived traits shared with other kinetoplastids. Their genetic repertoires are more diverse than the best-studied free-living kinetoplastids, which is likely a reflection of their higher metabolic potential. Mitochondrial RNAs of these new species undergo the most extensive U insertion/deletion editing reported so far, and limited deaminative C-to-U and A-to-I editing, but we find no evidence for mitochondrial trans-splicing.
Parvimonas micra, Peptostreptococcus stomatis, Fusobacterium nucleatum and Akkermansia muciniphila as a four-bacteria biomarker panel of colorectal cancer
Authors: Osman Muhammad Afiq , Neoh Hui-min , Ab Mutalib Nurul-Syakima , Chin Siok-Fong , Mazlan Luqman , Raja Ali Raja Affendi , Zakaria Andee Dzulkarnaen , Ngiu Chai Soon , Ang Mia Yang , Jamal Rahman
Published: February 2021

Dysbiosis of the gut microbiome has been associated with the pathogenesis of colorectal cancer (CRC). We profiled the microbiome of gut mucosal tissues from 18 CRC patients and 18 non-CRC controls of the UKM Medical Centre (UKMMC), Kuala Lumpur, Malaysia. The results were then validated using a species-specific quantitative PCR in 40 CRC and 20 non-CRC tissues samples from the UMBI-UKMMC Biobank. Parvimonas micra, Fusobacterium nucleatum, Peptostreptococcus stomatis and Akkermansia muciniphila were found to be over-represented in our CRC patients compared to non-CRC controls. These four bacteria markers distinguished CRC from controls (AUROC = 0.925) in our validation cohort. We identified bacteria species significantly associated (cut-off value of > 5 fold abundance) with various CRC demographics such as ethnicity, gender and CRC staging; however, due to small sample size of the discovery cohort, these results could not be further verified in our validation cohort. In summary, Parvimonas micra, Fusobacterium nucleatum, Peptostreptococcus stomatis and Akkermansia muciniphila were enriched in our local CRC patients. Nevertheless, the roles of these bacteria in CRC initiation and progression remains to be investigated.
Accurate and confident prediction of electron beam longitudinal properties using spectral virtual diagnostics
Authors: Hanuka A. , Emma C. , Maxwell T. , Fisher A. S. , Jacobson B. , Hogan M. J. , Huang Z.
Published: February 2021

Longitudinal phase space (LPS) provides a critical information about electron beam dynamics for various scientific applications. For example, it can give insight into the high-brightness X-ray radiation from a free electron laser. Existing diagnostics are invasive, and often times cannot operate at the required resolution. In this work we present a machine learning-based Virtual Diagnostic (VD) tool to accurately predict the LPS for every shot using spectral information collected non-destructively from the radiation of relativistic electron beam. We demonstrate the tool’s accuracy for three different case studies with experimental or simulated data. For each case, we introduce a method to increase the confidence in the VD tool. We anticipate that spectral VD would improve the setup and understanding of experimental configurations at DOE’s user facilities as well as data sorting and analysis. The spectral VD can provide confident knowledge of the longitudinal bunch properties at the next generation of high-repetition rate linear accelerators while reducing the load on data storage, readout and streaming requirements.