bluuebunny/crossref_metadata_2025 huggingface dataset:
The emergence of SARS-CoV-2 in Europe and North America
Authors: Worobey Michael , Pekar Jonathan , Larsen Brendan B. , Nelson Martha I. , Hill Verity , Joy Jeffrey B. , Rambaut Andrew , Suchard Marc A. , Wertheim Joel O. , Lemey Philippe
Published: September 2020

A series of unfortunate events

The history of how severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread around the planet has been far from clear. Several narratives have been propagated by social media and, in some cases, national policies were forged in response. Now that many thousands of virus sequences are available, two studies analyzed some of the key early events in the spread of SARS-CoV-2. Bedford
et al.
found that the virus arrived in Washington state in late January or early February. The viral genome from the first case detected had mutations similar to those found in Chinese samples and rapidly spread and dominated subsequent undetected community transmission. The other viruses detected had origins in Europe. Worobey
et al.
found that early introductions into Germany and the west coast of the United States were extinguished by vigorous public health efforts, but these successes were largely unrecognized. Unfortunately, several major travel events occurred in February, including repatriations from China, with lax public health follow-up. Serial, independent introductions triggered the major outbreaks in the United States and Europe that still hold us in the grip of control measures.

Science
, this issue p.
571
, p.
564
Structural basis for the inhibition of cGAS by nucleosomes
Authors: Kujirai Tomoya , Zierhut Christian , Takizawa Yoshimasa , Kim Ryan , Negishi Lumi , Uruma Nobuki , Hirai Seiya , Funabiki Hironori , Kurumizaka Hitoshi
Published: September 2020

Saving a host cell from itself

A fundamental mammalian defense mechanism against pathogens and damaged cellular DNA is to recognize DNA fragments in the cytosol and trigger an inflammatory response. The cyclic guanosine monophosphate–adenosine monophosphate synthase (cGAS) that recognizes cytosolic DNA is also found in the nucleus, but here its activity is suppressed by tethering to chromatin. Two papers now report cryo–electron microscopy structures of cGAS bound to the nucleosome core particle (NCP). Kujirai
et al.
observed a structure with two cGAS molecules bridging two NCPs, whereas Boyer
et al.
observed cGAS bound to a single nucleosome. Together, these structures show how cGAS is prevented from autoreactivity toward host DNA.

Science
, this issue p.
455
, p.
450
Activity of Aztreonam in Combination with Avibactam, Clavulanate, Relebactam, and Vaborbactam against Multidrug-Resistant Stenotrophomonas maltophilia
Authors: Biagi M. , Lamm D. , Meyer K. , Vialichka A. , Jurkovic M. , Patel S. , Mendes R. E. , Bulman Z. P. , Wenzler E.
Published: September 2020

The intrinsic L1 metallo- and L2 serine-β-lactamases in
Stenotrophomonas maltophilia
make it naturally multidrug resistant and difficult to treat. There is a need to identify novel treatment strategies for this pathogen, especially against isolates resistant to first-line agents. Aztreonam in combination with avibactam has demonstrated potential, although data on other aztreonam–β-lactamase inhibitor (BLI) combinations are lacking. Additionally, molecular mechanisms for reduced susceptibility to these combinations have not been explored.
In Vitro
and
In Vivo
Evaluation of an Adamantyl-Based Phenyl Sulfonyl Acetamide against Cutaneous Leishmaniasis Models of
Leishmania amazonensis
Authors: Santos Camila C. , Zhang Huaisheng , Batista Marcos M. , de Oliveira Gabriel M. , Demarque Kelly C. , da Silva-Gomes Natália L. , Moreira Otacílio C. , Ogungbe Ifedayo Victor , Soeiro Maria de Nazaré C.
Published: September 2020

Phenotypic assay against
Leishmania amazonensis
in vitro
and
in vivo
led to identification of an adamantyl-based phenyl sulfonyl acetamide (compound 1) as a promising antileishmanial agent. Compound 1 inhibited the growth of intracellular forms of
L. amazonensis
(50% inhibitory concentration [IC
50
] = 4 μM) and exhibited low toxicity to host cells, with a selectivity index (SI) of >125. However, in a cutaneous leishmaniasis (CL) mouse model, compound 1 did not reduce lesions and parasite load when administered as monotherapy or when given simultaneously with a suboptimal dose of miltefosine.
Mutations Identified in the Hepatitis C Virus (HCV) Polymerase of Patients with Chronic HCV Treated with Ribavirin Cause Resistance and Affect Viral Replication Fidelity
Authors: Mejer Niels , Fahnøe Ulrik , Galli Andrea , Ramirez Santseharay , Weiland Ola , Benfield Thomas , Bukh Jens
Published: September 2020

Ribavirin has been used for 25 years to treat patients with chronic hepatitis C virus (HCV) infection; however, its antiviral mechanism of action remains unclear. Here, we studied virus evolution in a subset of samples from a randomized 24-week trial of ribavirin monotherapy versus placebo in chronic HCV patients, as well as the viral resistance mechanisms of the observed ribavirin-associated mutations in cell culture. Thus, we performed next-generation sequencing of the full-length coding sequences of HCV recovered from patients at weeks 0, 12, 20, 32 and 40 and analyzed novel single nucleotide polymorphisms (SNPs), diversity, and mutation-linkage.
Understanding why at-risk population segments do not seek care for tuberculosis: a precision public health approach in South India
Authors: Helfinstein Sarah , Engl Elisabeth , Thomas Beena E , Natarajan Gayathri , Prakash Prithivi , Jain Mokshada , Lavanya Jayabal , Jagadeesan Murugesan , Chang Rebekah , Mangono Tichakunda , Kemp Hannah , Mannan Shamim , Dabas Harkesh , Charles Grace K , Sgaier Sema K
Published: September 2020

Introduction

Delaying care-seeking for tuberculosis (TB) symptoms is a major contributor to mortality, leading to worse outcomes and spread. To reduce delays, it is essential to identify barriers to care-seeking and target populations most at risk of delaying. Previous work identifies barriers only in people within the health system, often long after initial care-seeking.

Methods

We conducted a community-based survey of 84 625 households in Chennai, India, to identify 1667 people with TB-indicative symptoms in 2018–2019. Cases were followed prospectively to observe care-seeking behaviour. We used a comprehensive survey to identify care-seeking drivers, then performed multivariate analyses to identify care-seeking predictors. To identify profiles of individuals most at risk to delay care-seeking, we segmented the sample using unsupervised clustering. We then estimated the per cent of the TB-diagnosed population in Chennai in each segment.

Results

Delayed care-seeking characteristics include smoking, drinking, being employed, preferring different facilities than the community, believing to be at lower risk of TB and believing TB is common. Respondents who reported fever or unintended weight loss were more likely to seek care. Clustering analysis revealed seven population segments differing in care-seeking, from a retired/unemployed/disabled cluster, where 70% promptly sought care, to a cluster of employed men who problem-drink and smoke, where only 42% did so. Modelling showed 54% of TB-diagnosed people who delay care-seeking might belong to the latter segment, which is most likely to acquire TB and least likely to promptly seek care.

Conclusion

Interventions to increase care-seeking should move from building general awareness to addressing treatment barriers such as lack of time and low-risk perception. Care-seeking interventions should address specific beliefs through a mix of educational, risk perception-targeting and social norms-based campaigns. Employed men who problem-drink and smoke are a prime target for interventions. Reducing delays in this group could dramatically reduce TB spread.
Arms sales and child health
Authors: Feinstein Andrew , Choonara Imti
Published: September 2020

The adverse effects of armed conflict on child health are well recognised. The relationships among the arms trade, armed conflict and child health are less clearly defined. The arms trade is one of the largest industries in the world (total expenditure US$1917 billion in 2019), generating colossal profits to private companies and individuals at the expense of taxpayers throughout the world. The money wasted on weapons designed to kill and maim should be used for more socially useful products, such as clean water, food, health and education. The sustainable development goals can be funded by diverting money from the arms companies. Health professionals and their organisations have a responsibility to children to try and curb the ever-expanding arms industry.
Medicaid expansion and infant mortality: the (questionable) impact of the Affordable Care Act
Authors: Cook Amanda , Stype Amanda
Published: September 2020

Background

Many states expanded Medicaid eligibility under the Patient Protection and Affordable Care Act (PPACA). Medicaid expansion might impact infant mortality through improved maternal health prior to pregnancy and reduced insurance churn. Some studies suggest the PPACA had no significant impact on low birth weight or preterm birth, while others suggest that the PPACA led to a significant decrease in infant mortality.

Methods

Using a difference-in-differences estimator with fixed effects to control for differences in state characteristics and time trends we analyse three samples of births from the CDC’s linked birth/death files from 2011 to 2017 to estimate the impact of Medicaid expansion on infant mortality.

Results

We find mixed results. In our full sample, we find no statistically significant change in infant mortality associated with PPACA Medicaid expansion. However, when we restrict the sample to states who had adopted the 2003 birth certificate form and when we further exclude states with a Medicaid waiver, in both samples we see reductions in infant mortality for babies born to mothers of all races. When we stratify by race, we find infant mortality decreased for babies born to white mothers. However, this decrease is not seen for babies born to black mothers.

Conclusions

Medicaid expansion under the PPACA has an impact on infant mortality, but the results are sensitive to the sample of states included in the study. There is suggestive evidence that Medicaid expansion is not closing the infant mortality gap between black and white babies.
BRAF inhibitor resistance of melanoma cells triggers increased susceptibility to natural killer cell-mediated lysis
Authors: Frazao Alexandra , Rethacker Louise , Jeudy Géraldine , Colombo Marina , Pasmant Eric , Avril Marie-Françoise , Toubert Antoine , Moins-Teisserenc Helene , Roelens Marie , Dalac Sophie , Maubec Eve , Caignard Anne
Published: September 2020

Background

Targeted therapies and immunotherapies are first-line treatments for patients with advanced melanoma. Serine–threonine protein kinase B-RAF (BRAF) and mitogen-activated protein kinase (MEK) inhibition leads to a 70% response rate in patients with advanced melanoma with aBRAFV600E/Kmutation. However, acquired resistance occurs in the majority of patients, leading to relapse. Immunotherapies that activate immune cytotoxic effectors induce long-lasting responses in 30% of patients. In that context, combination of targeted therapies with immunotherapy (IT) is a promising approach. We considered boosting natural killer (NK) cell tumor immunosurveillance, as melanoma cells express stress-induced molecules and activate NK cell lysis.

Methods

Here we have generated vemurafenib (a BRAF inihibitor)-resistant (R) cells fromBRAFV600ESK28 and M14-sensitive (S) melanoma cell lines and investigated how resistance interferes with immunogenicity to NK cells. We determined the levels of several soluble molecules including NK ligands in 61 melanoma patients at baseline and 6 months M post-treatment with targeted therapies or immunotherapies.

Results

Vemurafenib resistance involved activation of p-AKT in SK28R and of p-MEK/p-ERK in M14R cells and was accompanied by modulation of NK ligands. Compared with S cells, SK28R displayed an increased expression of natural killer group 2 D (NKG2D) receptor ligands (major histocompatibility complex class (MHC) I chain-related protein A (MICA) and UL16-binding protein 2 (ULBP2)) whereas M14R exhibited decreased ULBP2 . SK28R and M14R cells induced higher NK degranulation and interferon gamma secretion and were more efficiently lysed by donor and patient NK cells. SK28R showed increased tumor necrosis factor-related apoptosis-inducing ligand receptor II (TRAIL-RII) expression and TRAIL-induced apoptosis, and TRAIL-induced apoptosis of M14R was decreased. Combined BRAF/MEK inhibitors abrogated the growth of SK28S, M14S, and M14R cells, while growth of SK28R was maintained. BRAF/MEK inhibition attenuated NK activity but R cell lines activated polyfunctional NK cells and were lysed with high efficiency. We investigated the relationship of soluble NK ligands and response to treatment in a series of melanoma patients. Soluble NKG2D ligands known to regulate the receptor function have been associated to cancer progression. Serum analysis of patients treated with target therapies or IT indicates that soluble forms of NK ligands (MICA, B7H6, programmed cell death ligand 1, and carcinoembryonic antigen cell adhesion molecule 1) may correlate with clinical response.

Conclusion

These results support strategies combining targeted therapies and NK-based immunotherapies.
Ethics of placebo use in clinical practice: why we need to look beyond deontology
Authors: Plowman Rosanna , Spurr Sally
Published: September 2020

Beneficent clinical usage of placebos has been a problem for the application of Kant’s deontology in medical ethics, which, in its strictest form, rejects deception universally. Some defenders of deontology have countered this by arguing placebos can be used by a physician without necessarily being deceptive. In this paper we argue that such a manipulation of Kant’s absolutism is not credible, and therefore, that we should look beyond deontology in our consideration of placebo usage in clinical practice. We conclude that Kant’s deontology cannot be made compatible with placebo use in clinical practice due to the primacy it affords to the principle of autonomy.
A resource optimization framework for improving railway-highway grade crossing safety in Canada
Authors: Thakali Lalita , Fu Liping , Heydari Shahram
Published: September 2020

This paper presents a new approach to address the problem of allocating federal resources and identifying upgrading projects for improving the safety of at-grade crossings in Canada. The proposed approach is unique in two key aspects. First, a risk-based network screening process is adopted to identify the priority sites for providing a justifiable basis for distributing the total budget at a regional level as well as narrowing the search space in the subject optimization step. Secondly, a mathematical programming approach is applied to formalize the resource allocation process with explicit consideration of the expected benefits – risk reduction and the costs of implementing the projects. This approach is expected to improve the process of identifying the optimal set of upgrading projects within each region, thus maximizing the return on investment. A full-scale case study from the Canadian crossing network is conducted to demonstrate the application of the proposed approach.
Development of droplet digital PCR assays to quantify genes involved in nitrification and denitrification, comparison with quantitative real-time PCR and validation of assays in vineyard soil
Authors: Voegel Tanja M. , Larrabee Melissa M. , Nelson Louise M.
Published: September 2020

Quantifying genes in soil is important to relate the abundance of soil bacteria to biogeochemical cycles. Quantitative real-time PCR is widely used for quantification, but its use with environmental samples is limited by poor reaction efficiencies or by PCR inhibition through co-purified soil substances. Droplet digital PCR (ddPCR) is a technology for absolute, sensitive quantification of genes. This study optimized eight ddPCR assays to quantify total bacteria and archaea as well as the nitrification (bacterial and archaeal amoA) and denitrification (nirS, nirK, nosZI, nosZII) genes involved in the generation or reduction of the greenhouse gas nitrous oxide. Detection and quantification thresholds were compared with those of quantitative real-time PCR and were equal to, or improved, in ddPCR. To validate the assays using environmental samples, soil DNA was isolated from two vineyards in the Okanagan valley in British Columbia, Canada, over the 2017 growing season. Soil properties related to the observed gene abundances were determined. Total bacteria, nirK, and nosZII increased with time and the soil C/N ratio and NH4+-N concentration affected total archaea and archaeal amoA negatively. The results, compared with those of other studies, showed that ddPCR is a valid alternative to qPCR to quantify genes involved in nitrification or denitrification.
Combination of Scutellaria baicalensis and Metformin Ameliorates Diet-Induced Metabolic Dysregulation in Mice via the Gut–Liver–Brain Axis
Authors: Ansari AbuZar , Bose Shambhunath , Lim Soo-Kyoung , Wang Jing-Hua , Choi Young-Hee , Kim Hojun
Published: September 2020

Scutellaria baicalensis (SB), a herbal medicine, is commonly used to treat metabolic diseases, while Metformin (MF) is a widely used drug for type 2 diabetes. The purpose of this study was to investigate whether co-treatment of SB with MF could produce a potential therapeutic effect on high-fat and high-fructose diet (HFFD)-induced metabolic dysregulation. First, we optimized the dose of SB (100, 200, 400, and 800[Formula: see text]mg/kg) with MF (200[Formula: see text]mg/kg) in HFFD-induced C57BL6J mice. Next, the optimized dose of SB (400[Formula: see text]mg/kg) was co-administered with MF (50, 100, and 200[Formula: see text]mg/kg) in a similar animal model to find the effective combinations of SB and MF. Metabolic markers were determined in serum and tissues using different assays, histology, gene expression, and gut microbial population. The SB and MF co-treatment significantly decreased the body, liver, and VAT weights. The outcome of OGTT was improved, and the fasting insulin, HbA1c, TG, TC, LDL-c, AST, and ALT were decreased, while HDL-c was significantly increased. Histological analyses revealed maintained the integrity of liver, adipose tissue, and intestine prevented lipid accumulation in the liver and intestine and combated neuronal damage in the brain. Importantly, controlled the expression of PPAR[Formula: see text], and IL-6 genes in the liver, and expression of BDNF, Glut1, Glut3, and Glut4 genes in the brain. Treatment-specific gut microbial segregation was observed in the PCA chart. Our findings indicate that SB and MF co-treatment is an effective therapeutic approach for HFFD-induced metabolic dysregulation which is operated through the gut–liver–brain axis.
Natural Product Luteolin Rescues THAP-Induced Pancreatic β-Cell Dysfunction through HNF4α Pathway
Authors: Wu Wenyu , He Shijun , Shen Yuli , Zhang Jiawen , Wan Yihong , Tang Xiaodong , Liu Shuwen , Yao Xingang
Published: September 2020

Endoplasmic reticulum stress (ER stress) plays a main role in pancreatic [Formula: see text]-cell dysfunction and death because of intracellular Ca[Formula: see text] turbulence and inflammation activation. Although several drugs are targeting pancreatic [Formula: see text]-cell to improve [Formula: see text]-cell function, there still lacks agents to alleviate [Formula: see text]-cell ER stress conditions. Therefore we used thapsigargin (THAP) or high glucose (HG) to induce ER stress in [Formula: see text]-cell and aimed to screen natural molecules against ER stress-induced [Formula: see text]-cell dysfunction. Through screening the Traditional Chinese drug library ([Formula: see text] molecules), luteolin was finally discovered to improve [Formula: see text]-cell function. Cellular viability results indicated luteolin reduced the THAP or HG-induced [Formula: see text]-cell death and apoptosis through MTT and flow cytometry assay. Moreover, luteolin improved [Formula: see text]-cell insulin secretion ability under ER stress conditions. Also ER stress-induced intracellular Ca[Formula: see text] turbulence and inflammation activation were inhibited by luteolin treatment. Mechanically, luteolin inhibited HNF4[Formula: see text] signaling, which was induced by ER stress. Moreover, luteolin reduced the transcriptional level of HNF4[Formula: see text] downstream gene, such as Asnk4b and HNF1[Formula: see text]. Conversely HNF4[Formula: see text] knockdown abolished the effect of luteolin on [Formula: see text]-cell using siRNA. These results suggested the protective effect of luteolin on [Formula: see text]-cell was through HNF4[Formula: see text]/Asnk4b pathway. In conclusion, our study discovered that luteolin improved [Formula: see text]-cell function and disclosed the underlying mechanism of luteolin on [Formula: see text]-cell, suggesting luteolin is a promising agent against pancreatic dysfunction.
Complexity growth for topological black holes by holographic method
Authors: Nagasaki Koichi
Published: September 2020

We consider the growth of the action for black hole space–time with a fundamental string. Our interest is to find the difference of the behavior between black holes with three different topologies in the scenario of complexity-action conjecture. These black holes have positive, negative and zero curvatures. We would like to calculate the action growth of these systems with a probe fundamental string according to the complexity-action conjecture. We find that for the case where the black holes have the toroidal horizon structure this probe string behaves very differently from the other two cases.
The vacuum electromagnetic energy density — Towards a physical comprehension of the vacuum energy scale problem
Authors: Meis Constantin
Published: September 2020

The electromagnetic field ground state, a zero-energy cosmic field permeating all of space, issues naturally from Maxwell’s electromagnetic theory and its fluctuations may generate transient photons conferring a physical solution to the vacuum energy scale problem. They are more significant at long wavelengths underlying principally the low frequency up to infrared cosmic radiation background. Assuming an exponentially decreasing probability with increasing frequency for the fluctuating photons the obtained vacuum energy density is in agreement with the astrophysical observations. Consequently, the electromagnetic field ground state fluctuations might be the principal component of the dark energy considered responsible for the observed cosmic acceleration.
Kerr–Bolt black hole entropy and soft hair
Authors: Setare M. R. , Jalali A.
Published: September 2020

Recently it has been speculated that a set of infinitesimal [Formula: see text] diffeomorphisms exist which act nontrivially on the horizon of some black holes such as Kerr and Kerr–Newman black holes.[Formula: see text] Having applied this symmetry in covariant phase space formalism, one can obtain Virasoro charges as surface integrals on the horizon. Kerr–Bolt space–time is well known for its asymptotically topology and has been studied widely in recent years. In this work, we are interested to find conserved charge associated to the Virasoro symmetry of Kerr–Bolt geometry using covariant phase space formalism. We will show right and left central charge are [Formula: see text], respectively. Our results also show good agreement with Kerr space–time in the limiting behavior.
Jacobi–Trudi type formula for a class of irreducible representations of 𝔤𝔩(m|n)
Authors: Bình Nguyên Luong Thái
Published: September 2020

We prove a determinantal type formula to compute the characters of a class of finite-dimensional irreducible representations of the general Lie super-algebra [Formula: see text] in terms of the characters of the symmetric powers of the fundamental representation and their duals. This formula, originally conjectured by van der Jeugt and Moens, can be regarded as a generalization of the well-known Jacobi–Trudi formula.
Structural similarity preserving GAN for infrared and visible image fusion
Authors: Zhang Di , Zhou Yong , Zhao Jiaqi , Zhou Ziyuan , Yao Rui
Published: September 2020

Compared with a single image, in a complex environment, image fusion can utilize the complementary information provided by multiple sensors to significantly improve the image clarity and the information, more accurate, reliable, comprehensive access to target and scene information. It is widely used in military and civil fields, such as remote sensing, medicine, security and other fields. In this paper, we propose an end-to-end fusion framework based on structural similarity preserving GAN (SSP-GAN) to learn a mapping of the fusion tasks for visible and infrared images. Specifically, on the one hand, for making the fusion image natural and conforming to visual habits, structure similarity is introduced to guide the generator network produce abundant texture structure information. On the other hand, to fully take advantage of shallow detail information and deep semantic information for achieving feature reuse, we redesign the network architecture of multi-modal image fusion meticulously. Finally, a wide range of experiments on real infrared and visible TNO dataset and RoadScene dataset prove the superior performance of the proposed approach in terms of accuracy and visual. In particular, compared with the best results of other seven algorithms, our model has improved entropy, edge information transfer factor, multi-scale structural similarity and other evaluation metrics, respectively, by 3.05%, 2.4% and 0.7% on TNO dataset. And our model has also improved by 0.7%, 2.82% and 1.1% on RoadScene dataset.
Modeling and numerical simulations for a prey–predator model with interference among predators
Authors: Surendar M. S. , Sambath M.
Published: September 2020

In this paper, we modeled a prey–predator system with interference among predators using the Crowley–Martin functional response. The local stability and existence of Hopf bifurcation at the coexistence equilibrium of the system in the absence of diffusion are analyzed. Further, the stability of bifurcating periodic solutions is investigated. We derived the conditions for which nontrivial equilibrium is globally asymptotically stable. In addition, we study the diffusion driven instability, Hopf bifurcation of the corresponding diffusion system with zero flux boundary conditions and the Turing instability region regarding parameters are established. The stability and direction of Hopf bifurcation are determined by applying the normal form theory and the center manifold theorem. Numerical simulations are performed to illustrate the theoretical results.
Who Needs College? We'll Sell You a Diploma!
Authors: Neal Lisa
Published: September 2020

Email spam might be a blessing in disguise. If academic institutions want to communicate more effectively the should think of how to stand apart from the spammers. A simple line about accreditation is a good start; anything that puts distance between legitimate offerings and dreaded diploma-mill spam is probably a good idea.
Book Review: 'The Connected Company' by Dave Gray
Authors: Quinn Clark
Published: September 2020

In this review, Clark Quinn sings praises for "The Connected Company." Dave Gray's new book explores how the world is changing, how companies need to adapt, and how they can do so effectively. Gray examines how organizations are connecting and engaging with customers, partners, and employees.
Transition from Tradition: 9 Tips for successfully moving your face-to-face course online
Authors: MacGregor-Mendoza Patricia
Published: September 2020

Many successful face-to-face educators who are interested in moving their courses online feel overwhelmed by the prospect of transitioning to a virtual delivery format. This article offers a set of practical tips to address some of the most common challenges of this process and make the teaching of online courses constructive and enjoyable for students and teachers alike.
From One-to-one to Many-to-many: Powering peer learning in open learning environments
Authors: Ram Preetha
Published: September 2020

Social learning platforms improve the learning experience for online learners when they are built for collaboration and community. Social and peer tutoring interactions lead to enduring relationships between members, which in turn keep the members engaged in the pursuit of their goals. When peer learners teach one another, work collaboratively on a problem, interact socially, and build relationships with each other, they then develop a sense of belonging and make the behavioral transition from disengage to engaged learners. OpenStudy is a social learning platform that offers a much-needed informal online learning space, and connects learners who help one another.
A Balancing Act Part I: Technical Support and the Online Instructor
Authors: Shamsy Jennifer
Published: September 2020

Technical issues can create a barrier to fully accessing and engaging in online classrooms. The need to support learners in overcoming these barriers may be addressed through a team approach or by individual instructors/trainers taking on the technical support role. While this role may not always be clearly defined or formally delegated, assuming the role of technical support in an online classroom has both benefits and drawbacks. Perceived benefits from an instructor/trainer's point-of-view include accommodating learner preferences, acquisition of new technological skills, and development of personalized responses for learners while perceived drawbacks can be seen as increased time requirements, acquisition of needless technical skills, and additional workload.
Revolutionize Learning and Development; An e-Learning Manifesto for All of Us
Authors: Rocco Stevie
Published: September 2020

Clark Quinn's new book, "Revolutionize Learning and Development," offers many insights and suggestions for the changes that are needed for learning and performance in organizations going forward. From the need for data to how we conceive of a "course," the text outlines next steps that organizations can take to optimize performance.
A Wake up Call for Practitioners
Authors: Blunden Helen
Published: September 2020

With organizations facing many challenges today, what role does the learning professional have to play? And how can they help their organization succeed in today's changing business world?
Learning is Social with Zoom Video Conferencing in your Classroom
Authors: Sutterlin Jane
Published: September 2020

Zoom has become a robust, indispensable and reliable video conferencing tool for the way we work, teach and learn together. When we create a positive social learning environment with supportive faculty and student relationships, we are able to retain our online students. Zoom connects easily across room systems, desktops and mobile devices to seamlessly bring together our various campus sites and long-distance participants. Utilizing the numerous features of zoom creates an authentic online teaching environment.
The Hilbert method for transducer equivalence
Authors: Bojańczyk Mikołaj
Published: September 2020

This Hilbert Method, as discussed in this paper, is the idea to encode combinatorial objects used by automata, such as words or trees, into algebraic objects, such as numbers and polynomials, and to reason about the latter using results about polynomials like Hilbert's Basis Theorem. A typical application of the method is deciding of equivalence for string-to-string transducers that use registers.
Digital resources in education
Authors: Tripathi Arun Kumar
Published: September 2020

How does technology change learning and teaching in formal and informal education?
Complexity in the interface Age
Authors: Ubiquity staff
Published: September 2020

Do you control technology or does it control you? Jeremy J. Shapiro talks about the power struggle in machine/human relationships and what it means today to be information-technology literate. Shapiro is a faculty member in the Human and Organization Development Program at the Fielding Graduate Institute.
Product language in electronic media design
Authors: Klein Steffen
Published: September 2020

Communication follows function: How products communicate to users and why designers should care.
A conversation with Herbert R.J. Grosch
Authors: Ubiquity staff
Published: September 2020

Reflections on the early days of computing, the importance of standards, and The Old Man.
A conversation with Ruby Lee
Authors: Ubiquity staff
Published: September 2020

Innovative computer scientist Ruby Lee talks about secure information processing, efficient permutations, fair use in the digital age, and more.
Review of 'Highly parallel computations: Algorithms and applications,' by M.P. Bekakos
Authors: Hutchins Ron
Published: September 2020

How scientists will use "metacomputational" facilities to solve complex problems.
Robert Aiken on the future of learning
Authors: Ubiquity staff
Published: September 2020

In the hands of skilled teachers, technology will provide students with the best possible education -- both face-to-face and distant, collaborative and individualized, and entertaining and instructional.
Intellectual property rights of multimedia enriched websites
Authors: Shoniregun Charles Adetokunbo
Published: September 2020

Can original print and music survive the multimedia technology hoax?
Communications policy and information technology
Authors: Cranor Lorrie Faith , Greenstein Shane
Published: September 2020

Policy analysis involves tempering enthusiasm with a sobering dose of reality.
At the crossroads of technology and policy
Authors: Ubiquity staff
Published: September 2020

Lorrie Cranor on privacy, online voting and Internet censorship.
Clock driven scheme to initialize the sequence number
Authors: Kim Chong
Published: September 2020

Using TCP deal with delayed duplicates of both old and new connections
The Virtues of Virtual
Authors: Ubiquity staff
Published: September 2020

Abbe Mowshowitz talks about virtual organization as way of managing activities and describes the rise of virtual feudalism.
From thinkers to clickers
Authors: Thirunarayanan M. O.
Published: September 2020

Tick-tock, time clicking away
A Meeting of the Minds
Authors: Campbell Marisa E.
Published: September 2020

In the halls of Denver University, over 1,500 miles away, undergraduate students are speaking one-on-one with the likes of Bob Dole, Dee Dee Myers, and Newt Gingrich via satellite from C-Span's Distance Learning studio in Washington D.C. These students are part of a five-year experiment named the Amos B. Hostetter Distance Learning Program, which began early last year and is being funded by cable pioneer Amos B. Hostetter.
Building Innovative Corporate Learning Beyond the Workplace
Authors: Stricklin Robin
Published: September 2020

Presented is a case stud on Delta Air Lines' Delta U, a three pronged program designed to support continuous learning for employees through formal education beyond the workplace.
Fault management in mobile computing
Authors: Saha Goutam Kumar
Published: September 2020

Business people on the go need portability and mobility in their computing environments. However, such mobile environments often suffer from transient faults. This article discusses how to manage faults in order to get better availability for small wireless devices.
Talking with security expert M. E. Kabay
Authors: Ubiquity staff
Published: September 2020

Adaptive attackers, novice computer users, indifferent management - it's no wonder our defensive mechanisms need continuous refinement.
High-level language translation in SYMBOL 2R
Authors: Anderberg J. W. , Smith C. L.
Published: September 2020

The SYMBOL 2R Computing System represents an attempt to bridge the gap between machine languages and higher level programming languages. This gap has always limited the users' ability to communicate with the machine, thus creating a communication problem. Early attempts at solving this communication problem consisted of developing a series of user-oriented programming languages, i.e., assembler languages and higher level languages, supplemented with a host of translator programs that would transform the higher level languages into machine language. For several years it seemed that this approach represented the only economically feasible solution. In 1965, W. H. Burkhardt (2) suggested the development of high-level language computers

Burkhardt did suggest that the availability of low cost components would make high-level language computers an economically feasible solution. In fact, the recent decline in the cost of components as compared with the steady, if not increasing cost of the software needed to develop and maintain compilers for high-level languages, has made the high-level language computer solution seem even more attractive.
Instruction architecture of an aerospace multiprocessor
Authors: Miller James S. , Vandever Woodrow H.
Published: September 2020

This paper describes the architecture, the data forms, and the instruction set of a multiprocessor computer designed to provide the central computational facilities of a long-lifetime orbiting space laboratory. An overview of the system [M73] describes other aspects of the design, including its high level of fault-tolerance, flexible capacity, real time control capability, and process security in the presence of software faults. The present treatment emphasizes the considerations which led to the chosen instruction set, and discusses its design relative to system objectives.
The HP 3000 computer system
Authors: Bartlett Joel F.
Published: September 2020

The HP 3000 (1) is a 16-bit multiprogramming computer. Multiprogramming is facilitated through the use of a virtual memory scheme using code and data segmentation. The impetus for this machine was HP's growth in the time sharing market. The original offering in this area was the 2000A, a BASIC system using the HP 2116. This use and real-time demands from HP's other divisions led to the 3000's development. The 2100 (2), the 2116's successor and classical one-address machine, did not readily lend itself to multiprogramming, but the 3000 was designed with this in mind.

From the beginning, the 3000 involved inputs from both hardware and software development teams. The end machine was designed with the operating system in mind and with a high level systems programming language (SPL) as the implementation tool for the operating system (MPE, multiprogramming executive) and all sub-systems. The Burroughs influence is evident in these choices.

Separate code and data segmentation with segments of variable length is the heart of the hardware and software system. A program consists of one or more code segments and a data segment. The data segment, also known as the stack, is used for a program's global and temporary storage. It also contains a stack used for operations and procedure return addresses.
A high order language optimal execution processor Fast Intent Recognition System (FIRST)
Authors: Schroeder S. C. , Vaughn L. E.
Published: September 2020

The history of digital computers represents a twofold development toward the common goal of harnessing “electronic energy” to solve human problems. On the one hand we have the hardware designers producing faster, cheaper, more versatile computers to execute larger, more complex programs. On the other hand we have the software designers generally producing faster, cheaper, and more versatile languages, compilers, operating systems, and application software with which to program these larger, more complex problems. It is only recently that timesharing and interactive systems have begun to bridge the hardware-software generation gap. This paper describes a system which is intended to eliminate the gap by providing a computer which directly executes a powerful language - APL - in a highly efficient manner. The programmer and machine communicate entirely in APL with a fully interactive timesharing operating system integral in the design. In particular this paper focuses on the execution aspects of the computer and relates results obtained by emulating the main processor to conventional computer approaches.
A hierarchical machine model for the semantics of programming languages
Authors: Basili Victor R. , Turner Albert J.
Published: September 2020

A formal definitional facility for specifying the semantics of a programming language should provide a tool that aids in the design, definition, implementation and comparison of programming languages. This paper deals with the development of such a facility.

The purpose of this paper is to demonstrate this formal definitional facility by modeling a specific programming language and to point out the possibilities for using it to relate the semantic complexity of the language with the complexity of the machine required to interpret it.
On the time required for retention
Authors: Berry D. M. , Chirica L. , Johnston J. B. , Martin D. F. , Sorkin A.
Published: September 2020

In block structured languages, upon entry to a block or procedure, storage is allocated for the identifiers declared in the block or procedure. There are two choices as to when to deallocate this storage:

1) upon exit from the block or procedure,

2) when the storage becomes inaccessible.

In the deletion strategy, storage for blocks and procedures is allocated and deallocated in a last-in-first-out order. Therefore, storage for blocks and procedures can be managed efficiently on a pushdown stack. However, deletion gives rise to dangling references in the use of pointer, label, and procedure values.

Retention is both more secure and more general in that it eliminates all possibility of dangling references, and it therefore removes all restrictions on the use of pointer, label, and procedure values.

This paper develops an implementation of generalized (single task) block structured languages with compile time type determinability, which is capable of handling full retention but which keeps the run time cost of many well-stacked programs near that of the same program on a typical ALGOL 68 style implementation.
Ethical and social aspects of biotechnology Ethical and social aspects of biotechnology
Authors: Irrgang Bernhard
Published: September 2020

The globalisation of biotechnology brings not only new economic prospects but also new risks. The development of international bio-safety guidelines is essential.
The more things change, the more (and less) they stay the same
Authors: Chakravorti Bhaskar
Published: September 2020

Bhaskar Chakravorti tells how the network hinders, then helps market innovation
Emotional design
Authors: Norman Donald A.
Published: September 2020

Beauty and brains, pleasure and usability go hand-in-hand in good design.
2004, The turning point
Authors: Downes Stephen
Published: September 2020

An overview of some of the issues that will change the way we use the Internet
Instructional Design for Flow in Online Teaching
Authors: Ceraulo Sandra C.
Published: September 2020

This tutorial, a sequel to "Instructional Design for Flow in Online Learning" published in eLearn in 2003, explains how the process of designing instruction can be a creative and enjoyable artistic experience for the online teacher and for the instructional designer.
It is not what you do, it is whom you do it with
Authors: Andersen Espen
Published: September 2020

Telecom strategy 101: In network markets, use network marketing
Legal issues involved in E-commerce
Authors: Nasir M. Ali
Published: September 2020

The exponential growth of the Internet and online activity raise a number of new regulatory issues and legal questions.
Roger Brent and the alpha project
Authors: staff Ubiquity
Published: September 2020

The work of a multidisciplinary genomic research lab in Berkeley may yield big changes in drug therapy and medicine. Roger Brent is President and Research Director of the Molecular Sciences Institute, an independent nonprofit research laboratory in Berkeley, CA, that combines genomic experimentation with computer modeling. The mission of the MSI is to predict the behavior of cells and organisms in response to defined genetic and environmental changes.
An Interview with Steven Weber
Authors: staff Ubiquity
Published: September 2020

Author Steven Weber looks beyond the hype on Open Source. More than a self-governing utopia, it's a practical, sustainable way of organizing and innovating. Its method may soon be applied successfully in other sectors. Plus, a "crazy" idea for Microsoft.
Impact of Frictional Interactions on Conductivity, Diffusion, and Transference Number in Ether- and Perfluoroether-Based Electrolytes
Authors: Grundy Lorena S. , Shah Deep B. , Nguyen Hien Q. , Diederichsen Kyle M. , Celik Hasan , DeSimone Joseph M. , McCloskey Bryan D. , Balsara Nitash P.
Published: September 2020

There is growing interest in fluorinated electrolytes due to their high-voltage stability. We use full electrochemical characterization based on concentrated solution theory to investigate the underpinnings of conductivity and transference number in tetraglyme/LiTFSI mixtures (H4) and a fluorinated analog, C8-DMC, mixed with LiFSI (F4). Conductivity is significantly lower in F4 than in H4, and F4 exhibits negative cation transference numbers, while that of H4 is positive at most salt concentrations. By relating Stefan-Maxwell diffusion coefficients, which quantify ion-solvent and cation-anion frictional interactions, to conductivity and transference number, we determine that at high salt concentrations, the origin of differences in transference number is differences in anion-solvent interactions. We also define new Nernst-Einstein-like equations relating conductivity to Stefan-Maxwell diffusion coefficients. In H4 at moderate to high salt concentrations, we find that all molecular interactions must be included. However, we demonstrate another regime, in which conductivity is controlled by cation-anion interactions. The applicability of this assumption is quantified by a pre-factor,

β

+
−

,

which is similar to the “ionicity” pre-factor that is often included in the Nernst-Einstein equation. In F4,

β

+
−

is unity at all salt concentrations, indicating that ionic conductivity is entirely controlled by the Stefan-Maxwell diffusion coefficient quantifying cation-anion frictional interactions.
Improving SOFC Anode Electrocatalytic Activity Using Nanoparticle Infiltration into MIEC Compositions
Authors: Mo Boshan , Rix Jillian , Pal Uday , Basu Soumendra , Gopalan Srikanth
Published: September 2020

Mitigating activation polarization in the anode is one of the major challenges in intermediate-temperature operation of solid oxide fuel cells (SOFCs). Liquid phase infiltration of nanoscale electrocatalysts has been shown to result in significant reductions in activation polarization in SOFC anodes. In this study, we explore liquid-phase infiltration of nickel, gadolinium doped ceria (GDC), and Ni/GDC electrocatalysts into two different types of cermet anodes: one with a conventional Ni-YSZ composition, and the other with a Ni-MIEC cermet anode where the YSZ has been doped with 3 mol% TiO2 to impart electronic conductivity. The principal goal of this study is to explore the role of electronic transport in the MIEC phase in effective utilization of the infiltrated nanoscale electrocatalysts. The role of temperature, infiltration cycles and the type of electrocatalysts have been experimentally studied in symmetric cells using electrochemical impedance spectroscopy (EIS). Distribution of relaxation times (DRT) modeling has been used to elucidate the contributions of various charge transfer processes.