cssi/SciSciGPT-SciSciNet huggingface dataset:
Influence of social and technical factors for evaluating contribution in GitHub

Open source software is commonly portrayed as a meritocracy, where decisions are based solely on their technical merit. However, literature on open source suggests a complex social structure underlying the meritocracy. Social work environments such as GitHub make the relationships between users and between users and work artifacts transparent. This transparency enables developers to better use information such as technical value and social connections when making work decisions. We present a study on open source software contribution in GitHub that focuses on the task of evaluating pull requests, which are one of the primary methods for contributing code in GitHub. We analyzed the association of various technical and social measures with the likelihood of contribution acceptance. We found that project managers made use of information signaling both good technical contribution practices for a pull request and the strength of the social connection between the submitter and project manager when evaluating pull requests. Pull requests with many comments were much less likely to be accepted, moderated by the submitter's prior interaction in the project. Well-established projects were more conservative in accepting pull requests. These findings provide evidence that developers use both technical and social information when evaluating potential contributions to open source software projects.
Global Spread of Mobile Antimicrobial Drug Resistance Determinants in Human and Animal Escherichia coli and Salmonella Strains Causing Community-Acquired Infections

Background Antimicrobial drugs used in human infection treatment and animal husbandry may select for drug-resistant bacterial pathogens, which are increasingly observed worldwide. We sought to examine the extent to which identical mobile drug resistance elements are shared across common pathogens isolated from human and animal sources. Methods We compared the distribution of one class of mobile elements--integrons and gene cassettes--among uropathogenic Escherichia coli isolates, Salmonella enterica serovar Typhimurium isolates from human diarrhea cases, and E. coli and Salmonella isolates from nonhuman sources in the United States. The sequences of the gene cassettes were also compared with those deposited in GenBank. Results Class 1 integrons were detected in 68 (49%) of 139 uropathogenic E. coli isolates, 16 (72%) of 22 human and animal Salmonella isolates, and 120 (28%) of 436 nonhuman E. coli isolates. The most prevalent cassettes were those encoding aminoglycoside adenyltransferase A (aadA) and dihydrofolate reductase A (dfrA). Sequences of aadA1, dfrA12-orfF-aadA2, and dfrA17-aadA5 gene cassettes from 35 urinary tract infection E. coli isolates and of aadA2 and aadA12 gene cassettes from 7 Salmonella isolates were 100% identical to the corresponding cassette sequences from food animal E. coli isolates and those deposited in GenBank from a wide variety of bacteria isolated from animal hosts from distinct regions of the world. Conclusion Common community-acquired human drug-resistant infections are caused by bacterial strains that harbor mobile drug resistance determinants of identical sequences that are found in diverse bacterial species from varied animal sources worldwide.
Ions in Flames

Originally, studies of ionization in flames were motivated by the observation that in hydrocarbon flames, the ion concentration far exceeds the value expected if ionization were due to thermal processes alone(1,2) (see Table I). The objectives of these studies were to explain the source of nonequilibrium ionization and to explore links between flame ionization and the mechanism of flame propagation. An explanation of the source of flame ions was found in the process of chemi-ionization.(2) This led to further studies of the details of ionic reactions which occur in flames and of flame reactions which can be induced by the addition of foreign elements.
The digital divide: a comparison of online consumer health information for African-American and general audiences.

This work was presented, in part, at the American Public Health Association 2007 Annual Program of Health Informatics Information Technology. Objectives We sought to assess the quality of health information on internet sites with missions to serve African Americans and to compare the quality to that of sites targeting a general audience. Methods Sites were identified by entering “black Health,” “African American health,” and “health” into 2 search engines. Websites were assessed for quality and usability by 2 independent readers using published criteria. Results Disease-specific information was found on 64.7% of African-American sites and 86.2% of general sites. Among these sites, 73% of African-American sites listed authors’ qualifications, compared to 96% of general sites (p=0.04). Sixty-four percent of African-American sites provided date last updated, compared with 100% of general sites (p=0.001). The mean literacy level for both types of sites was ~ 10th grade. The literacy level of African-American sites at governmental and educational domains was lower (NS). Conclusions This is the first study to examine critically the quality of health information on Internet sites serving African-American audiences. Our study suggests methods to guide healthcare providers and health educators in counseling patients regarding internet-based health information. The “digital divide” is about quality as well as access.
Fostering Diagonal Regulatory Initiatives

The structure of law poses a fundamental difficulty for effective regulation of multiscalar, intergenerational problems like climate change; law’s scale is sticky despite the fluid scalar nature of greenhouse gas emissions and impacts. In other words, we have subdivided law into levels of governance - a sensible idea for creating order and administrability - and formal regulation tends to happen within the fixed frames of those structures. As a result, we generally approach regulation as choosing or coordinating among those levels. The current policy debates over climate regulation reflect those constraints. As a range of individuals and entities work to develop the next major treaty on climate change and to determine appropriate executive and legislative action at national and subnational scales, consistent interaction across levels and branches of government is often quite limited. For example, local governments are working in transnational coalitions, but those cities and counties rarely have a meaningful place at the table in treaty negotiations. As the U.S. Congress continues to explore major legislation, it is unclear the extent to which proposed statutes will attempt to preempt smaller scale efforts and litigation. This Recommendation argues for the importance of exploring the possibilities and limitations of what it terms diagonal regulatory strategies, ones that cut across vertical and horizontal levels of government. It claims that more such approaches are needed to address this problem effectively, and in so doing limit its impact on future generations. Part I describes climate change as a multiscalar, intergenerational regulatory problem that current efforts are not addressing adequately. Part II discusses the context of current U.S. legislative debates as a practical example of the vertical, horizontal, and socio-cultural forces that impact potential statutory schemes. Part III introduces diagonal regulatory strategies as a possible mechanism for moving the policy dialogue forward. The Recommendation concludes by reflecting upon the next steps needed to address this spatially and temporally cross-cutting problem at the intersection of law and science.
Nonaqueous electrocatalytic water oxidation by a surface-bound Ru(bda)(L) 2 complex

The rate of electrocatalytic water oxidation by the heterogeneous water oxidation catalyst [Ru(bda)(4-O(CH2)3P(O3H2)2-pyr)2], 1, (pyr = pyridine; bda = 2,2′-bipyridine-6,6′-dicarboxylate) on metal oxide surfaces is greatly enhanced relative to water as the solvent. In these experiments with propylene carbonate (PC) as the nonaqueous solvent, water is the limiting reagent. Mechanistic studies point to atom proton transfer (APT) as the rate limiting step in water oxidation catalysis.
Professional Learning Communities: Keeping the Focus on Instructional Practice.

AbstractThe inclusion of professional learning community (PLC) groups is now a common initiative in many districts across the country. While this step supports the professional development of teachers, an effective PLC program must go beyond just bringing colleagues together during a common time. The author recommends organizational structures for schools to implement in order to maximize collaborative time.
Tunable Plasmon–Phonon Polaritons in Layered Graphene–Hexagonal Boron Nitride Heterostructures

We use infrared spectroscopy to explore the hybridization of graphene plasmons and hexagonal boron nitride (hBN) phonons in their heterostructures with different compositions. We show that the degree of plasmon–phonon hybridization and the slowing of the light group velocity within the infrared transparency window due to the plasmon–phonon destructive interference are dominated by hBN phonon oscillating strength, which can be tuned by varying the hBN thickness in a layer-by-layer manner. However, the plasmon oscillating strength in metallic graphene governs the magnitude of infrared extinction, which exceeds 6% at around 7 μm in a graphene/hBN/graphene heterostructure due to the strong plasmon dipole–dipole coupling. Our work demonstrates that the infrared optical responses of graphene–hBN heterostructures can be engineered by controlling the coupling strength of plasmon–phonon hybridization and the overall plasmon oscillating strength simultaneously, thus opening the avenue for the light manipulation and...
Introduction to Credit Networks: Security, Privacy, and Applications

Credit networks model transitive IOweYou (IOU) credit between their users. With their flexible-yet-scalable design and robustness against intrusion, we are observing a rapid increase in their popularity as a backbone of real-world permission-less payment settlement networks (e.g., Ripple and Stellar) as well as several other weak-identity systems requiring Sybil-tolerant communication. In payment scenarios, due to their unique capability to unite emerging crypto-currencies and user-defined currencies with the traditional fiat currency and banking systems, several existing and new payment enterprises are entering in this space. Nevertheless, this enthusiasm in the market significantly exceeds our understanding of security, privacy, and reliability of these inherently distributed systems. Currently employed ad hoc strategies to fix apparent flaws have made those systems vulnerable to bigger problems once they become lucrative targets for malicious players. In this tutorial, we first define the concept of IOU credit networks, and describe some of the important credit network applications. We then describe and analyze recent and ongoing projects to improve the credit-network security, privacy and reliability. We end our discussion with interesting open problems and systems challenges in the field. This introductory tutorial is accessible to the standard CCS audience with graduate-level security knowledge.
Study of Dynamic Warpage of Flip Chip Packages under Temperature Reflow

Flip chip deforms after assembly due to coefficient of thermal expansion mismatch of silicon and substrate coupled with underfills. Issues arise when excessive package warpage leads to improper joint during surface mount technology and increase in assembly yield loss. In this paper, application of shadow moire technique and finite element modeling approach were introduced to study the thermo-mechanical response of various package types, material set and geometrical parameters example silicon die and substrate size. Finite element modeling results showed the package geometry has more influence on warpage with die and package size parameter for package without integrated heat spreader (I-HS).
Of Absolute Concentrations of NADH in Cells using the Phasor Flim Method

One of the properties of fluorescence lifetime is its independence on concentration. While this is considered to be an advantage, when analyzing images of cell and tissues we often need to also measure the absolute concentration of a fluorophore. The concentration value is commonly obtained by comparison of the intensity of the fluorophore in the tissue and in a solution of known concentration. The underlying hypothesis is that the quantum yield of the fluorophore is the same in the sample and in the solution used for calibration. In cells and tissue this assumption is not always valid especially for a fluorophore like NADH that changes the quantum yield by a large factor when free in solution with respect to when bound to enzymes. We propose a graphical method using the phasor representation of the fluorescence decay to derive the absolute concentration of NADH in cells. The method requires the measurement of a solution of NADH at a known concentration. The phasor representation of the fluorescence decay accounts for the differences in quantum yield of the free and bound form of NADH, pixel by pixel of an image. The concentration of NADH in every pixel in a cell is obtained after adding to each pixel in the phasor plot a given amount of unmodulated light which causes a shift of the phasor towards the origin by an amount that depends on the intensity at the pixel and the fluorescence lifetime at the pixel. The absolute concentration of NADH is obtained by comparison of the shift obtained at each pixel of an image with the shift of the calibrated solution. Work supported in part by NIH grants NIH P41-GM103540 and NIH P50-GM076516.
THE IMPACT OF EPICARDIAL COLLATERAL USE ON THE OUTCOMES OF CHRONIC TOTAL OCCLUSION PERCUTANEOUS CORONARY INTERVENTION: INSIGHTS FROM A CONTEMPORARY MULTICENTER REGISTRY

Background: We examined the impact of the type of collateral vessel used on the outcomes of retrograde chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Methods: The baseline clinical and angiographic characteristics and procedural outcomes of 704 retrograde CTO PCIs performed
Sums and Grounding

ABSTRACTAs I will use the term, an object is a mereological sum of some things just in case those things compose it simply in virtue of existing. In the first half of this paper, I argue that there are no sums. The key premise for this conclusion relies on a constraint on what, in certain cases, it takes for something to ground, or metaphysically explain, something else. In the second half, I argue that in light of my argument against sums, Universalism, which is perhaps the most widely accepted answer to the Special Composition Question, is false.
Room Temperature Processing of TiOx Electron Transporting Layer for Perovskite Solar Cells

In order to realize high-throughput roll-to-roll manufacturing of flexible perovskite solar cells, low-temperature processing of all device components must be realized. However, the most commonly used electron transporting layer in high-performance perovskite solar cells is based on TiO2 thin films processed at high temperature (>450 °C). Here, we demonstrate room temperature solution processing of the TiOx layer that performs as well as the high temperature TiO2 layer in perovskite solar cells, as evidenced by a champion solar cell efficiency of 16.3%. Using optical spectroscopy, electrical measurements, and X-ray diffraction, we show that the room-temperature processed TiOx is amorphous with organic residues, and yet its optical and electrical properties are on par with the high-temperature TiO2. Flexible perovskite solar cells that employ a room-temperature TiOx layer with a power conversion efficiency of 14.3% are demonstrated.
Ni–Al Films on Glassy Carbon Electrodes Generate an Array of Oxygenated Organics from CO2

The transformation of CO2 into chemical feedstocks or fuels is an attractive goal, but catalysts capable of generating useful, multicarbon products have been challenging to design. Here, thin films of the intermetallic Ni3Al on glassy carbon are found to be electrocatalytic for aqueous CO2 reduction. At–1.38 V vs Ag/AgCl, Ni3Al films produce a range of C1, C2, and C3 oxygenated organic species including 1-propanol and methanol at Faradaic efficiencies that are competitive with single-metal electrodes reported in the literature. To the best of our knowledge, Ni3Al on glassy carbon is the only noncopper-containing material shown to generate C3 products.
Philosophy of Education in Action: An Inquiry-Based Approach

Philosophy of Education in Action is an innovative, inquiry-based introductory text that invites readers to study philosophy of education through the lens of their own observations and experiences. Structured according to a "Wonder Model of Inquiry," each chapter begins by posing a fundamental What if question about curriculum, pedagogy, and the role of the school before investigating the various philosophical perspectives that guide and influence educational practices. Classroom vignettes and examples of actual schools and educational programs help to ground philosophical perspectives in real-world scenarios, while the book’s unique inquiry-based approach leads students to both think critically about philosophical questions and apply the concepts to their own teaching. Features of the text include: What if questions that structure each chapter to pique students' curiosity, stimulate creativity, and promote critical thinking. Authentic classroom vignettes that encourage students to analyze what it means to "do" philosophy and to reflect upon their own practices, examine their role in the educational process, and articulate their own philosophical beliefs. A concluding section asking readers to imagine and design their own hypothetical school or classroom as a project-based means of analyzing, synthesizing, and evaluating the different philosophies discussed. Accessible and thought-provoking, Philosophy of Education in Action provides a dynamic learning experience for readers to understand and apply philosophy in educational practice.
Can the salt-advection feedback be detected in internal variability of the atlantic meridional overturning circulation?

AbstractEvidence for the assumptions of the salt-advection feedback in box models is sought by studying the Atlantic meridional overturning circulation (AMOC) internal variability in the long prein...
The Role of Predators in Ecosystem Management

Predators rarely receive priority attention in considerations of maintenance or restoration of ecosystems, yet both functionally and symbolically, predators are central to these considerations. Predators play a key role in maintaining ecosystem integrity in terms of species and genetic composition, ecosystem functions, and long term stability.
Clinical Strategies in Brief Psychotherapy

With the many works now appearing on the various forms of brief psychotherapy, this type of clinical intervention is long past the point where its use in clinical practice needs justification. Almost everyone, it seems, is doing at least some brief therapy, whereas others have adopted it as their major, if not exclusive method. An earlier paper (Wells & Phelps, 1990) reviewed the array of social, economic, ethical, and metaphilosophic factors that have contributed to this trend, and they will not be repeated here.
Case 61: Sudden Increase in End-Tidal CO2

Today your first case of the day is a 2-year-old boy (15 Kg and American Society of Anesthesiologists physical status I [ASA 1]) for an inguinal hernia repair. This is to be his first general anesthetic. His biological parents have not had a general anesthetic, and there is no family history of anesthetic complications.
Kinetics of phenylacetylene selective hydrogenation to styrene over metal-free polymeric carbon nitrides

Abstract Hydrogenation of carbon–carbon multiple bonds is one of the most important processes widely used in chemical synthesis. We have shown for the first time that graphite-like carbon nitrides are capable of activating hydrogen molecules in the absence of any metals and can be successfully used as solid catalyst for the selective hydrogenation of phenylacetylene to styrene. This article presents the results of the investigation of the catalytic activity of mesoporous carbon nitride in the reaction of partial hydrogenation of phenylacetylene in the range of temperature 150–250 °C in the gas phase and at atmospheric pressure. The kinetic regularities of the reaction have been studied. A probable mechanism and the kinetic model of the reaction are formulated on the basis of the observed trends in the dependence of the initial rate from the temperature, concentration of phenylacetylene and catalyst mass.
Real-Time Guidance, Navigation and Control Framework for Fixed-Wing Aircraft Maneuvers in a Vertical Plane

The goal of this study is to create a real-time guidance, navigation and control (GNC) framework for a fixed-wing aircraft (FWA) to perform various maneuvers in a vertical plane. This study offers a new approach for improving the FWA autonomy by enabling real-time sensor data fusion, targeting and re-targeting capabilities, new analytical/ numerical trajectory and attitude control solutions, and target-relative guidance. Existing FWA dynamical models are based on the traditional decoupling of their motion. This paper extends the utility of the concept of an instantaneous screw axis in guidance and control thereby promoting a new vision to general 6-degrees-of-freedom rigid body motion control. The existing flight vehicle guidance and control functions are mainly iterative and implicit, platform-specific, utilize pre-determined target states or way points, and executed typically utilizing the decoupled motion dynamical models. The research presented in this paper produces the GNC framework with the real-time target-relative guidance system, which is explicit and free of iterations, provide an onboard computation of the target states, executable for an uncoupled motion, and adjustable to various FWA and other unmanned aerial system platforms. An illustrative example is considered for a FWA maneuver in a vertical plane.
Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines on the Role of Emerging and Investigational Therapties for the Treatment of Adults With Metastatic Brain Tumors.

QUESTION What evidence is available regarding emerging and investigational treatment options for metastatic brain tumors? TARGET POPULATION Adult patients with brain metastases. RECOMMENDATIONS INTERSTITIAL MODALITIES There is insufficient evidence to make a recommendation regarding the routine use of existing local therapies, such as interstitial chemotherapy, brachytherapy, or other local modalities, aside from their use in approved clinical trials. IMMUNE MODULATORS There is insufficient evidence to make a recommendation regarding the use of immune therapy for brain metastases. MOLECULAR TARGETED AGENTS Level 1: The use of afatinib is not recommended in patients with brain metastasis due to breast cancer.There is insufficient evidence to make recommendations regarding: the use of epidermal growth factor receptor inhibitors erlotinib and gefitinib in patients with brain metastasis due to nonsmall cell lung cancerthe use of BRAF inhibitors dabrafenib and vemurafenib in the treatment of patients with brain metastases due to metastatic melanomathe use of HER2 agents trastuzumab and lapatinib to treat patients with brain metastases due to metastatic breast cancerthe use of vascular endothelial growth factor agents bevacizumab, sunitinib, and sorafenib in the treatment of patients with solid tumor brain metastases.The full guideline can be found at: https://www.cns.org/guidelines/guidelines-treatment-adults-metastatic-brain-tumors/chapter_9.
Historical Biogeography and Temporal Diversification in Symphoricarpos (Caprifolieae, Caprifoliaceae, Dipsacales)

The major aim of this paper was to investigate temporal diversification within Symphoricarpos (Caprifoliaceae, Dipsacales). We used recently published molecular sequences, along with fossil data, to examine when Symphoricarpos may have arrived in the New World and if current distributional patterns can be explained by data based on biogeographic, climatological, and geological events. We simultaneously estimated the phylogeny and divergence times within Symphoricarpos and related Caprifolieae species using BEAST. Based on these phylogenetic and divergence time estimations we reconstructed ancestral areas using the dispersal-extinction-cladogenesis (DEC) method implemented in Lagrange. For Symphoricarpos, our phylogenetic results inferred using BEAST were in strong agreement with previous studies, with a well-supported clade containing the North American species that was sister to the loneAsian species. Our divergence time results suggest that theNorth American species originated in the late Oligocene to mid Miocene (12–25 million years ago) and quickly diversified. The DEC area reconstructions suggest that after entering the North American continent from Asia, species of Symphoricarpos became widespread across the continent, followed by range restrictions to that of whatwe see today.Although several recent studies have argued for the idea of phylogenetic niche conservatism as a general explanation for characterizing broad biogeographic patterns, our data suggest significant niche evolution within the North American species of Symphoricarpos, especially in regard to taxa found in the southwestern parts of the USA andMexico. These observed biome shifts from mesic forest habitats to a much drier habitat appear to have happened across a highly diverse landscape in which species of Symphoricarpos occur. These results, along with results from other plant taxa, support the hypothesis that a climate shift in western North America played a role in the assemblage of the current flora via migration, as well as in situ adaptation in combination with diversification.
Volume-Outcome Relationships in Surgical and Endovascular Repair of Aortic Dissection.

Background As surgical mortality decreases and endovascular utilization increases, it is unknown whether volume-outcome relationships exist in thoracic aortic dissection repair. We characterized volume-outcome relationships for surgical and endovascular management of thoracic aortic dissection. Methods Patients aged more than 18 years undergoing repair of thoracic aortic dissection in the United States between 2010 and 2014 were identified in seven all-payer state inpatient administrative databases. Patients were divided into groups based on type of repair: surgical repair of type A dissection (TAAD), surgical repair of type B dissection (TBAD), and endovascular repair (TEVAR). Hierarchical logistic regression models evaluated the association between hospital volume and in-hospital mortality. Results Overall in-hospital mortality rate was 13.4% (890 of 6650), highest after TAAD (463 of 2918, 15.9%), followed by TBAD (270 of 1934, 14.0%) and TEVAR (157 of 1798, 8.7%). Volume-outcome relationships for adjusted in-hospital mortality were demonstrated for TAAD and TBAD (P-trend Conclusions This study demonstrated lower mortality at high-volume hospitals for overall repair of aortic dissection, persisting separately for surgical repair of TAAD and TBAD, but not TEVAR. As endovascular technology advances and practice patterns consequently change, analyses should focus on understanding the balance between procedural volume, mortality, and access to care for thoracic aortic dissection.
Has the US Bond Market Lost its Edge to the Eurobond Market

The growth of the European financial markets, together with the new, stricter regulations on the US financial markets, has spurred a debate over the competitiveness of the US financial markets. In this paper, we contribute to this debate by investigating the relative competitiveness of the US bond market over the last 10 years. In the early 1990s, the gross spread in the US bond market were significantly lower than in the Eurobond market. While this spread continued to decline in the US bond market, it declined at an even faster rate in the Eurobond market, to the point of eliminating the wide cost differential that existed between the two markets in the early 1990s. These findings are robust and suggest that the relative costs of bond underwriting declined in the Eurobond market. We also find that US firms are increasingly opting to issue their bonds in the Eurobond market, and that this relocation is partly driven by the decline in the relative gross spreads in the Eurobond market. This finding adds support to our conclusion that the cost of bond underwriting declined faster in the Eurobond market, reinforcing the view that the US bond market is facing a greater challenge from the Eurobond market.
Farmland Parcel Delineation Using Spatio-temporal Convolutional Networks

Farm parcel delineation provides cadastral data that is important in developing and managing climate change policies. Specifically, farm parcel delineation informs applications in downstream governmental policies of land allocation, irrigation, fertilization, green-house gases (GHG's), etc. This data can also be useful for the agricultural insurance sector for assessing compensations following damages associated with extreme weather events - a growing trend related to climate change. Using satellite imaging can be a scalable and cost effective manner to perform the task of farm parcel delineation to collect this valuable data. In this paper, we break down this task using satellite imaging into two approaches: 1) Segmentation of parcel boundaries, and 2) Segmentation of parcel areas. We implemented variations of UNets, one of which takes into account temporal information, which achieved the best results on our dataset on farmland parcels in France in 2017.
Media Narratives About Concussions: Effects on Parents’ Intention to Inform Their Children About Concussions:

This study examined the effects of media narratives about concussions on parent’s intentions to inform their children about concussions. A randomized experiment of 600 parents whose children play f...
Fuzzy Logic Navigation System for Autonomous Endovascular Operations

Endovascular operations are not only critical for the life of the patients but also very challenging for the surgeons. Such operations, require extensive surgical training, operative accuracy, and they are time consuming. Vascular robotics is identified as a solution that may facilitate vascular operations. This paper frames itself in the field of invasive robotics used for endovascular operations and proposes a new system for robot navigation. In particular, a fuzzy logic system is proposed that implements endovascular autonomous navigation of a robot in a patient. The fuzzy navigation system is tested on 3-dimensional simulations of the human aorta. The testing case demonstrates the ability of the fuzzy navigation to be an autonomous – i.e. no human intervention is required for navigation-and completes the navigation in the aorta with accuracy and speed.
Occupations by Proximity and Indoor/Outdoor Work: Relevance to COVID-19 in All Workers and Black/Hispanic Workers.

Introduction This paper describes the occupations in the U.S. that involve close contact with others and whether the work is outdoors or indoors (risk factors for COVID-19), including the distribution of Black and Hispanic workers over these occupations. Methods U.S. data released from 2014 to 2019 on employment, proximity to others at work, outdoor or indoor work, and Black and Hispanic worker percentages for occupations were used. Occupations were assigned to 6 categories defined as a low, medium, or high physical closeness (proximity) at work and outdoor or indoor work. A total of 3 of the 6 categories represent a higher risk for exposure to SARS-CoV-2: medium-proximity indoor, high-proximity outdoor, and high-proximity indoor exposure. Results A high proportion of U.S. workers may be at higher risk for exposure to SARS-CoV-2 because their occupations involve either high proximity to others indoors and outdoors (25.2%, 36.5 million workers) or medium-proximity indoors (48%, 69.6 million workers). There is a differential distribution of proximity and outdoor/indoor work by occupation, which disproportionately affects Black and Hispanic workers in some occupations. Conclusions Implementation of COVID-19 preventive measures in work settings should be based on occupation-specific risk factors, including the extent of proximity to others and whether the work is conducted outdoors or indoors. It is important that communication messages are tailored to the languages and preferred media of the workforce.
Shared Decision Making in Pediatrics: When the Burden Outweighs the Benefit. A Case Illustration from the Intensive Care Nursery

Background: Shared decision making between parents, patients, and health care providers is the accepted model of care in pediatrics and is predicated upon the principle of patient autonomy. However, at end of life in pediatric patients, there may be times that this model leads to excessive responsibility for parents. We present a case in which it became clear that it was incumbent …
Personality and media multitasking in the college classroom: Context-dependent implications of conscientiousness and agreeableness

Both personality and contexts may account for media multitasking in the college classroom. As this area of research was lacking, the present study examined which personality traits would be associated with in-class media multitasking in different contexts of text messaging. Undergraduate students (83 males and 65 females; average age: 20.0 [SD = 4.3]) completed a questionnaire on demographic characteristics, general text-messaging behavior, and Big Five personality traits as well as a delay-discounting task. This task had two hypothetical scenarios in which participants received either an urgent text message from their significant other (Significant Other condition) or a non-urgent message from a casual friend (Casual Friend condition), and they rated their likelihood of immediately replying to the message during the class versus waiting to reply until the class was over. For each of the conditions, hierarchical regression analyses were conducted to examine whether personality traits predicted the likelihood of waiting, after controlling for demographic characteristics and general text-messaging behavior. Whereas only conscientiousness independently predicted the likelihood of waiting in the Significant Other condition (β = .20, p = .033), only agreeableness independently predicted the likelihood in the Casual Friend condition (β = .27, p = .002). These findings contribute to the sparse literature on links of personality traits and in-class media multitasking by highlighting the possible context-dependent aspects of these links. The findings also indicate potential directions of future research including exploring approaches to reducing media multitasking in the college classroom while taking both personality and specific contexts into consideration.
One coin, two sides: eliciting expert knowledge from training participants in a capacity-building program for veterinary professionals

Scientific research may include the elicitation of judgment from non-academic subject-matter experts in order to improve the quality and/or impact of research studies. Elicitation of expert knowledge or judgment is used when data are missing, incomplete, or not representative for the specific setting and processes being studied. Rigorous methods are crucial to ensure robust study results, and yet the quality of the elicitation can be affected by a number of practical constraints, including the understanding that subject-matter experts have of the elicitation process itself. In this paper, we present a case of expert elicitation embedded within an extended training course for veterinary professionals as an example of overcoming these constraints. The coupling of the two activities enabled extended opportunities for training and a relationship of mutual respect to be the foundation for the elicitation process. In addition, the participatory research activities reinforced knowledge synthesis objectives of the educational program. Finally, the synergy between the two concurrent objectives may produce benefits which transcend either independent activity: solutions and ideas built by local professionals, evolving collaborative research and training approaches, and a network of diverse academic and practicing professionals. This approach has the versatility to be adapted to many training and research opportunities.
k-super cube root cube mean labeling of graphs

Consider a graph G with |V (G)| = p and |E(G)| = q and let f : V (G) → {k, k + 1, k + 2, . . . p + q + k − 1}} be an injective function. The induced edge labeling f ∗ for a vertex labeling f is defined by f ∗ (e) = for all e = uv ∈ E(G) is bijective. If f(V (G)) ∪ {f ∗ (e) : e ∈ E(G)} = {k, k + 1, k + 2, . . . , p + q + k − 1}, then f is called a k-super cube root cube mean labeling. If such labeling exists, then G is a k-super cube root cube mean graph. In this paper, I introduce k-super cube root cube mean labeling and prove the existence of this labeling to the graphs viz., triangular snake graph Tn, double triangular snake graph D(Tn), Quadrilateral snake graph Qn, double quadrilateral snake graph D(Qn), alternate triangular snake graph A(Tn), alternate double triangular snake graph AD(Tn), alternate quadrilateral snake graph A(Qn), & alternate double quadrilateral snake graph AD(Qn).
Discussion of ‘On studying extreme values and systematic risks with nonlinear time series models and tail dependence measures’

We congratulate Prof. Zhang for this timely review on recent advances in extreme value theory for heterogeneous populations and on time series models for extreme observations. This is a substantial...
More about Infinite Series

Infinite geometric sequences and series arise not only in pure mathematics but also in geometry, physics, and engineering, and at least one contemporary artist, Maurits C. Escher, has based on them many of his works. We shall examine some of these in the following chapters. Meanwhile, let us take a brief look at some other series, several of which mark important milestones in the history of mathematics. We have seen that the harmonic series 1 + 1/2 + 1/3 + 1/4 + … diverges. But the corresponding series with the squares of the natural numbers has baffled mathematicians for many years; among them were several of the Bernoulli brothers, who all failed to find its sum, although it had been known for some time that the series converges.1 It was the great Swiss mathematician Leonhard Euler (1707–1783) who finally solved the mystery.
The Puzzles of Material Constitution

Monists about material constitution typically argue that when Statue is materially constituted by Clay, Statue is just Clay. Pluralists about material constitution deny that constitution is identity: Statue is not just Clay. When Clay materially constitutes Statue, Clay is not identical to Statue. I discuss three familiar puzzles involving grounding, overdetermination and conceptual issues, and develop three new puzzles stemming from the connection between mereological composition and material constitution: a mereological puzzle, an asymmetry puzzle, and a structural puzzle.
Nitrogen Mineralization by Acanthamoeba polyphaga in Grazed Pseudomonas paucimobilis Populations

Nitrogen mineralization was studied in a simple grazing system in which the protozoan Acanthamoeba polyphaga was grown with the bacterium Pseudomonas paucimobilis (two soil organisms isolated from the shortgrass prairie in northern Colorado). In different experiments, either carbon or nitrogen was adjusted to be in limiting amounts. When carbon was limiting, grazers were almost entirely responsible for nitrogen mineralization, with bacteria themselves contributing little. When nitrogen was limiting, nitrogen mineralization by grazers permitted continued growth by the grazed bacteria and a greater bacterial biomass production. The increased growth of the grazed bacteria did not result in an increased total amount of carbon used, but the grazed bacteria used carbon more efficiently than the ungrazed bacteria.
Identification of a Novel "Fishbone" Structure in the Dendritic Growth of Columnar Ice Crystals

Ice crystals growing in highly supersaturated air at temperatures near -5 C exhibit a distinctive, nonplanar dendritic morphology that has not been previously documented or explained. We examine this structure and identify its most prominent features in relation to the ice crystal lattice. Developing a full 3D numerical model that reproduces this robust morphology will be an interesting challenge in understanding diffusion-limited crystal growth in the presence of highly anisotropic surface attachment kinetics.
Receptors for Bacterial Toxins

A review of Shiga toxin receptor, diphtheria toxin (DT) receptor, Pseudomonas exotoxin A (PEA) receptors will illustrate the different ways these molecules are studied and that bacterial toxins have harnessed a variety of processes to enter target cells. Evidence presented by researchers that low-density lipoprotein receptor-related protein (LRP) serves as the receptor for PEA is several-fold. First, both the toxin-binding protein purified from LM cells or mouse liver and LRP have similar mobility on SDS-PAGE and are indistinguishable immunologically. Second, native PEA, but not a mutant toxin defective in its ability to bind to LM cells, binds to purified LRP that is immobilized on polystyrene or on nitrocellulose; the toxin interacts with the 515-kDa heavy chain of LRP on ligand blots, not with the 85-kDa light chain. Third, receptor-associated protein (RAP) both blocks binding of PEA to mouse LM cells and abolishes toxicity. Cells expressing receptors with different-length juxtamembrane domains bind DT normally; however, they exhibit reduced sensitivity to DT when compared to wild-type cells. The three receptors have functions essential to the normal physiologic properties of mammalian cells. Nevertheless, they represent molecules usurped by different bacterial toxins as the first step in the intoxication process. Cells lacking functional cell surface receptor are resistant to the toxin, expression of receptor correlates with the tissue specificity of toxin damage, and this in turn correlates with the disease symptoms seen in animal models and in patients.
- CeRaf: LIN-45 Raf protein kinase (C. elegans)

The Caenorhabditis elegans raf gene was cloned using degenerate oligonucleotides and PCR protocols. A genomic fragment was cloned and shown to rescue the mutant phenotypes of a mutation in the lin-45 gene. This gene had been previously identified in a genetic screen for mutations that disrupt hermaphrodite vulval differentiation. Double mutant analysis with an activated let-60 ras mutation suggests that the lin-45 raf gene acts downstream of let-60 ras in the vulval induction pathway. CeRaf contains the three conserved domains, CR1, CR2, and CR3, found in other members of the Raf family. The lin-45 raf gene has been assayed in vivo for its effects on development using chromosomal mutations. It has also been assayed in vivo using transgenic animals carrying in vitro-generated dominant-negative mutations. The sy96 mutation affects vulval differentiation and fertility in the hermaphrodite, spicule formation in the male, and viability and P12 neuroectoblast specification in both sexes.
Inquiry-Based Teaching in the College Classroom: The Nontraditional Student

Science departments in higher education have been adjusting their curricula to include more inquiry-based instruction, and research on inquiry-based teaching at the collegiate level has been increasing. However, more data are needed regarding the effectiveness of inquiry-based pedagogy in improving students' conceptual understanding and attitudes toward science. The investigation described here was focused on nontraditional students taking non-science-major science courses. The goal was to compare students' attitudes toward science before and after taking an inquiry-based or a traditional science course. The hypothesis that the inquiry-based course would significantly generate a more positive attitude toward science was supported. Nontraditional students' perceptions of an effective science curriculum were also explored. Students' perceptions were very positive regarding inquiry-based learning; however, those who had not been previously taught through inquiry-based methods had reserved perceptions of this teaching approach. Regardless of the course they were enrolled in, students agreed overall that an effective science curriculum includes three common themes: connection, interaction, and application.
Diagnosis and treatment of urolithiasis in client-owned chelonians: 40 cases (1987–2012)

Objective—To calculate the prevalence of urolithiasis in client-owned chelonians examined at a veterinary teaching hospital and to describe the clinical signs, diagnosis, and treatment of urolithiasis in chelonians. Design—Retrospective case series. Animals—40 client-owned turtles and tortoises with urolithiasis. Procedures—The medical record database of a veterinary teaching hospital was searched from 1987 through 2012 for records of client-owned chelonians with urolithiasis. The prevalence of urolithiasis was calculated for client-owned chelonians examined at the hospital. Signalment and physical examination, hematologic, biochemical, urinalysis, diagnostic imaging, treatment, and necropsy results were described. Results—The mean prevalence of urolithiasis in client-owned chelonians for the study period was 5.1 cases/100 client-owned chelonians examined. Thirty-one of the 40 chelonians were desert tortoises. Only 5 of 40 chelonians had physical examination abnormalities associated with the urogenital tr...
Semidirect dynamical and radiative effect of North African dust transport on lower tropospheric clouds over the subtropical North Atlantic in CESM 1.0

This study uses a century length preindustrial climate simulation by the Community Earth System Model (CESM 1.0) to explore statistical relationships between dust, clouds, and atmospheric circulation and to suggest a semidirect dynamical mechanism linking subtropical North Atlantic lower tropospheric cloud cover with North African dust transport. The length of the run allows us to account for interannual variability of North African dust emissions and transport in the model. CESM's monthly climatology of both aerosol optical depth and surface dust concentration at Cape Verde and Barbados, respectively, agree well with available observations, as does the aerosol size distribution at Cape Verde. In addition, CESM shows strong seasonal cycles of dust burden and lower tropospheric cloud fraction, with maximum values occurring during boreal summer, when a strong correlation between these two variables exists over the subtropical North Atlantic. Calculations of Estimated Inversion Strength (EIS) and composites of EIS on high and low downstream North African dust months during boreal summer reveal that dust is likely increasing inversion strength over this region due to both solar absorption and reflection. We find no evidence for a microphysical link between dust and lower tropospheric clouds in this region. These results yield new insight over an extensive period of time into the complex relationship between North African dust and North Atlantic lower tropospheric clouds, which has previously been hindered by spatiotemporal constraints of observations. Our findings lay a framework for future analyses using different climate models and submonthly data over regions with different underlying dynamics.