bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in temperature and heat waves over Africa using observational and reanalysis data sets
Authors: Engdaw Mastawesha Misganaw , Ballinger Andrew P. , Hegerl Gabriele C. , Steiner Andrea K. 
Published: July 2021

AbstractProviding comprehensive regional‐ and local‐scale information on changes observed in the climate system plays a vital role in planning effective and efficient climate change adaptation options, specifically over resource‐limited regions. Here, we assess changes in temperature and heat waves over different regions of the African continent, with a focus on spatiotemporal trends and the time of emergence of change in hot extremes from natural variability. We analyse absolute and relative threshold indices. Data sets include temperatures from observations (CRUTS4.03 and BEST) and from three representative state‐of‐the‐art reanalyses (ERA5, MERRA2 and JRA‐55) for the common period 1980–2018. Statistically significant warming is observed over all regions of Africa in temperature time series from CRU observations and reanalysis data, although the trend strength varies between data sets. Also, extreme temperatures and heat wave indices from BEST observations and all reanalysis data sets reveal increasing trends over all regions of the African continent. However, there are differences in both trend strength and time evolution of heat wave indices between different reanalysis data sets. Most data sets agree in identifying 2010 as a peak heat year over Northern and Western Africa while Eastern and Southern Africa experienced the highest heat wave occurrence in 2016. Our results clearly reveal that heat wave occurrences have emerged from natural climate variability in Africa. The earliest time of emergence takes place in the Northern Africa region in the early 2000s while in the other African regions emergence over natural variability is found mainly after 2010. This also depends on the respective index metrics, where indices based on more consecutive days show later emergence of heat wave trends. Overall, significant warming and an increase in heat wave occurrence is found in all regions of Africa and has emerged from natural variability in the past one or two decades.
Effect of heat treatment on the chromium‐depleted zones of a high carbon martensitic stainless steel
Authors: Siqueira Jordânio S. , de Abreu Alves Marcos R. , Marcial Luiz Thaís , Renzetti Reny A. 
Published: July 2021

AbstractHeat treatments are commonly applied in the martensitic stainless steels to achieve high wear resistance and hardness; however, they can lead to a decrease in corrosion resistance due to the precipitation of chromium‐rich carbides. The present work investigates the effect of austenitizing and tempering parameters on the microstructure, hardness, and passivation and reactivation currents of AISI 440C. A double‐loop electrochemical potentiodynamic reactivation test is performed to evaluate the dissolution and precipitation of chromium‐rich carbides. The volume fraction of phases after heat treatment is estimated by X‐ray diffraction. Results show that an increase in the austenitizing temperature leads to an increase in the carbide dissolution, and also in the amount of retained austenite. As a consequence, low passivation and reactivation currents are obtained. When austenite is the main phase, the increase of austenitizing time contributed to an increase in the degree of sensitization due to austenite grain boundary carbon enrichment. However, the presence of austenite after tempering kept part of the carbon in a solid solution resulting in low passivation and reactivation currents.
High‐temperature high‐pressure SCC testing of corrosion‐resistant alloys
Authors: Galakhova Anastasiia , Prattes Karl , Mori Gregor 
Published: July 2021

AbstractStress corrosion cracking test methods of corrosion‐resistant alloys are reviewed. The interest to write a review on this topic was drawn by demands for oil country tubular goods applicable in deep wells with high pressures, high temperatures, and the presence of H2S, where stress corrosion cracking is one of the most critical failure modes. All conventional methods for determining the stress corrosion cracking resistance of an alloy, mainly slow strain rate testing, constant load testing (tensile, 4‐PB), constant strain testing (U‐bend, C‐ring), and fracture mechanics (double cantilever beam sample) are covered. Considering the variety of testing solutions, the field of search is narrowed to hot (up to 250°C) aqueous chloride solutions with dissolved H2S and CO2gases under high pressure (up to 200 bar total pressure).
Boundedness results for 2‐adic Galois images associated to hyperelliptic Jacobians
Authors: Yelton Jeffrey 
Published: July 2021

AbstractLetKbe a number field, and letCbe a hyperelliptic curve overKwith JacobianJ. Suppose thatCis defined by an equation of the form for some irreducible monic polynomial of discriminant Δ and some element . Our first main result says that if there is a prime ofKdividing but not (2Δ), then the image of the natural 2‐adic Galois representation is open in and contains a certain congruence subgroup of depending on the maximal power of dividing . We also present and prove a variant of this result that applies whenCis defined by an equation of the form for distinct elements . We then show that the hypothesis in the former statement holds for almost all and prove a quantitative form of a uniform boundedness result of Cadoret and Tamagawa.
STAT3 polymorphisms in North Africa and its implication in breast cancer
Authors: Ziadi Wafa , Boussetta Sami , Elkamel Sarra , Pakstis Andrew J. , Kidd Kenneth K. , Medimegh Imen , Ben Ammar Elgaaied Amel , Cherni Lotfi 
Published: July 2021

AbstractBackgroundOnly a few studies have investigated the association of single nucleotide polymorphisms in STAT3 gene with the susceptibility to cancer and response to chemotherapy. Our aim was to determine the allele frequencies of rs3869550, rs957971, and rs7211777 at the STAT3 gene in North African populations and compare them to 1000 genomes populations, and to investigate their relation with cancer.MethodsThe targeted SNPs have been analyzed in six Tunisian populations and a sample of Libyans using TaqMan® Assay. The results were compared to 1000 Genomes Project population samples. Targeting of the regions encompassing the three SNPs by micro‐ARN was assessed using miR databases.ResultsThe analysis of the 3 SNPs showed that North African populations were close to South Asians. As expected, African populations presented a significant frequency of the ancestral CCG haplotype in contrast to other populations where the fully derived TGA haplotype was more frequent. The presence and diversity of rare haplotypes at STAT3 in North African populations could have been generated by recombination between the two major haplotypes. A screening of the micro‐RNA databases showed that the STAT3 region with the mutated allele of rs7211777 (G>A) could be targeted by miR hsa‐miR‐3606‐5p, which also targets genes involved in breast cancer.
Technical Note: A preliminary study of dual‐tracer PET image reconstruction guided by FDG and/or MR kernels
Authors: Wang Haiyan , Huang Zhenxing , Zhang Qiyang , Gao Dongfang , OuYang Zhanglei , Liang Dong , Liu Xin , Yang Yongfeng , Zheng Hairong , Hu Zhanli 
Published: July 2021

AbstractPurposeClinically, single radiotracer positron emission tomography (PET) imaging is a commonly used examination method; however, since each radioactive tracer reflects the information of only one kind of cell, it easily causes false negatives or false positives in disease diagnosis. Therefore, reasonably combining two or more radiotracers is recommended to improve the accuracy of diagnosis and the sensitivity and specificity of the disease when conditions permit.MethodsThis paper proposes incorporating 18F‐fluorodeoxyglucose (FDG) as a higher‐quality PET image to guide the reconstruction of other lower‐count 11C‐methionine (MET) PET datasets to compensate for the lower image quality by a popular kernel algorithm. Specifically, the FDG prior is needed to extract kernel features, and these features were used to build a kernel matrix using a k‐nearest‐neighbor (kNN) search for MET image reconstruction. We created a 2‐D brain phantom to validate the proposed method by simulating sinogram data containing Poisson random noise and quantitatively compared the performance of the proposed FDG‐guided kernelized expectation maximization (KEM) method with the performance of Gaussian and non‐local means (NLM) smoothed maximum likelihood expectation maximization (MLEM), MR‐guided KEM, and multi‐guided‐S KEM algorithms. Mismatch experiments between FDG/MR and MET data were also carried out to investigate the outcomes of possible clinical situations.ResultsIn the simulation study, the proposed method outperformed the other algorithms by at least 3.11% in the signal‐to‐noise ratio (SNR) and 0.68% in the contrast recovery coefficient (CRC), and it reduced the mean absolute error (MAE) by 8.07%. Regarding the tumor in the reconstructed image, the proposed method contained more pathological information. Furthermore, the proposed method was still superior to the MR‐guided KEM method in the mismatch experiments.ConclusionsThe proposed FDG‐guided KEM algorithm can effectively utilize and compensate for the tissue metabolism information obtained from dual‐tracer PET to maximize the advantages of PET imaging.
A hybrid Laplace‐Galerkin method for thermo‐hydro‐mechanical coupling in fluid saturated porous media: Application for borehole problems
Authors: Nguyen‐Sy Tuan , Vu Minh‐Ngoc , Nguyen Thoi‐Trung 
Published: July 2021

AbstractA hybrid Laplace‐Galerkin method is proposed for modeling thermo‐hydro‐mechanical coupled problems of fluid saturated porous media in unsteady state regime. It consists of transforming the weak form equations into the Laplace space where they are solved by the Galerkin finite element method. Results in time space are then obtained by the Stehfest method of inverse Laplace transformation. This technique does not require any time stepping comparing to the traditional implicit or explicit time discretization method. Its exactitude is confirmed by comparing with existent analytical results as well as the one obtained by the implicit time stepping method.
Hands‐on horticulture: Lessons learned teaching online experiential horticulture during COVID‐19
Authors: Luby Claire , Tepe Emily , Irish Laura , Michaels Thomas , Hoover Emily 
Published: July 2021

AbstractAs a result of theCOVID‐19 pandemic, many courses were forced online. This posed particular challenges for courses with laboratory or hands‐on components. A group of instructors at the University of Minnesota and the University of Wisconsin‐Madison designed an online, asynchronous course structure for teaching introductory horticulture courses with laboratory components. Uniquely, the courses described in this article, while delivered through the online teaching platform Canvas, focused on developing hands‐on activities that got students away from their computers to observe, work with, and grow plants. The course included hands‐on activities that complemented lecture readings and videos and guided students through designing and setting up experiments in their homes. We heard many positive reviews from student course evaluations for this style of course and want to share the structure and the types of experiential activities we included to engage students with plants and the process of science, as well as lessons that we learned while teaching in this online learning environment. We found that the ability to care for and observe plants on a daily basis wove together the lecture and lab materials in ways that were not previously seen during in‐person courses. As instructors, we would adapt some of the components of these online courses into our in‐person courses in the future.
Could Nintendo’s Animal Crossing be a tool for conservation messaging?
Authors: Fisher Jessica C. , Yoh Natalie , Kubo Takahiro , Rundle Danielle 
Published: July 2021

Abstract

The current extinction crisis demands worldwide commitment to conservation across all sectors of society. By transcending the traditional disciplinary boundaries, conservationists can reach new audiences to communicate pro‐conservation knowledge, education and awareness messages.

There are approximately 2.7 billion video‐gamers worldwide, with millions more joining as a result of global lockdowns. In March 2020, Animal Crossing: New Horizons was released by Nintendo, fast becoming the second‐best selling video game ever in Japan, and selling over 26.4 million units worldwide. Unlike many popular video games, its unique premise involves players creating an island, growing vegetation, catching wildlife and donating fossils and species to a museum. The game has been praised for its positivity, escapism and measurable benefits to mental well‐being.

Here, we articulate how different features of the game, including the islands, their biodiversity and inhabitants, encourage players to exhibit pro‐conservation behaviours and attitudes (e.g. recycling litter, or planting a diversity of flowers), as well as improving players’ knowledge about the diversity of relatively little known taxa (marine and freshwater fishes and invertebrates). We also highlight where pitfalls exist (e.g. encouraging the collection of threatened species). We principally frame these discussions in the context of Japan's cultural relationship with the natural world, including its history of insect‐collecting and its management of green spaces. We conclude by outlining some recommendations about potential improvements to future releases, or for similar games, that could further promote conservation messaging.

This perspective sheds light on the avenues through which Animal Crossing: New Horizons encourages pro‐conservation knowledge, attitudes and behaviours of its international audience, with potential for these experiences to translate into real‐world conservation actions. During a critical time in humanity's history, video gaming could therefore provide a huge opportunity for communicating conservation messages to billions of people worldwide.

A free Plain Language Summary can be found within the Supporting Information of this article.
Leukaemia and lockdown: The delayed infection model of childhood acute lymphoblastic leukaemia and the COVID‐19 pandemic
Authors: Lillie Katy 
Published: July 2021

AbstractAcute lymphoblastic leukaemia (ALL) is the most common type of leukaemia diagnosed in children. The prevailing hypothesis regarding pathogenesis of childhood ALL was developed by Greaves, and states that ALL is caused by an abnormal immune response to a common infection. The response arises either due to naivety of the immune system caused by a lack of common childhood infections, or genetic susceptibility due to specific alleles. The former explanation is known as the delayed infection hypothesis. COVID‐19 is a new infection that no children in the UK were exposed to prior to 2020. Furthermore, the lockdown measures designed to prevent spread of this virus have also greatly reduced spread of other common infections. It is therefore important to examine the evidence for this hypothesis, and to consider it in the context of the pandemic to determine what effect lockdown measures may have on incidence of ALL in children.
Bias of time‐varying exposure effects due to time‐varying covariate measurement strategies
Authors: Penning de Vries Bas B. L. , Groenwold Rolf H. H. 
Published: July 2021

AbstractPurposeIn studies of effects of time‐varying drug exposures, adequate adjustment for time‐varying covariates is often necessary to properly control for confounding. However, the granularity of the available covariate data may not be sufficiently fine, for example when covariates are measured for participants only when their exposure levels change.MethodsTo illustrate the impact of choices regarding the frequency of measuring time‐varying covariates, we simulated data for a large target trial and for large observational studies, varying in covariate measurement design. Covariates were measured never, on a fixed‐interval basis, or each time the exposure level switched. For the analysis, it was assumed that covariates remain constant in periods of no measurement. Cumulative survival probabilities for continuous exposure and non‐exposure were estimated using inverse probability weighting to adjust for time‐varying confounding, with special emphasis on the difference between 5‐year event risks.ResultsWith monthly covariate measurements, estimates based on observational data coincided with trial‐based estimates, with 5‐year risk differences being zero. Without measurement of baseline or post‐baseline covariates, this risk difference was estimated to be 49% based on the available observational data. With measurements on a fixed‐interval basis only, 5‐year risk differences deviated from the null, to 29% for 6‐monthly measurements, and with magnitude increasing up to 35% as the interval length increased. Risk difference estimates diverged from the null to as low as −18% when covariates were measured depending on exposure level switching.ConclusionOur simulations highlight the need for careful consideration of time‐varying covariates in designing studies on time‐varying exposures. We caution against implementing designs with long intervals between measurements. The maximum length required will depend on the rates at which treatments and covariates change, with higher rates requiring shorter measurement intervals.
Retracted: Prevalence and factors associated with bone stress injury in middle school runners
Authors: Tenforde Adam S. , DeLuca Stephanie , Wu Alexander C. , Ackerman Kathryn E. , Lewis Margo , Rauh Mitchell J. , Heiderscheit Bryan , Krabak Brian J. , Kraus Emily , Roberts William , Troy Karen L. , Barrack Michelle T. 
Published: July 2021

AbstractBackgroundBone stress injury (BSI) in youth runners is clinically important during times of skeletal growth and is not well studied.ObjectiveTo evaluate the prevalence, anatomical distribution, and factors associated with running‐related BSI in boy and girl middle school runners.DesignRetrospective cross‐sectional study.SettingOnline survey distributed to middle school runners.MethodsSurvey evaluated BSI history, age, grade, height, weight, eating behaviors, menstrual function, exercise training, and other health characteristics.Main Outcome MeasurementsPrevalence and characteristics associated with history of BSI, stratified by cortical‐rich (eg, tibia) and trabecular‐rich (pelvis and femoral neck) locations.Participants2107 runners (n = 1250 boys, n = 857 girls), age 13.2 ± 0.9 years.ResultsOne hundred five (4.7%) runners reported a history of 132 BSIs, with higher prevalence in girls than boys (6.7% vs 3.8%, p = .004). The most common location was the tibia (n = 51). Most trabecular‐rich BSIs (n = 16, 94% total) were sustained by girls (pelvis: n = 6; femoral neck: n = 6; sacrum: n = 4). In girls, consuming <3 daily meals (odds ratio [OR] = 18.5, 95% confidence interval [CI] = 7.3, 47.4), eating disorder (9.8, 95% CI = 2.0, 47.0), family history of osteoporosis (OR = 6.9, 95% CI = 2.6, 18.0), and age (OR = 1.6, 95% CI = 1.0, 2.6) were associated with BSI. In boys, family history of osteoporosis (OR = 3.2, 95% CI = 1.2, 8.4), prior non‐BSI fracture (OR = 3.2, 95% CI = 1.6, 6.7), and running mileage (OR = 1.1, 95% CI = 1.0, 1.1) were associated with BSI. Participating in soccer or basketball ≥2 years was associated with lower odds of BSI for both sexes.ConclusionWhereas family history of osteoporosis and prior fracture (non‐BSI) were most strongly related to BSI in the youth runners, behaviors contributing to an energy deficit, such as eating disorder and consuming <3 meals daily, also emerged as independent factors associated with BSI. Although cross‐sectional design limits determining causality, our findings suggest promoting optimal skeletal health through nutrition and participation in other sports including soccer and basketball may address factors associated with BSI in this population.
Development of evidence‐based classification for para surfers with physical impairments: A narrative review
Authors: Johnson Maureen E. , David Heather M. 
Published: July 2021

AbstractThe sport of competitive para surfing is growing internationally without established classification procedures. A classification structure is essential for equitable sport competition and worldwide sport progression. This narrative review summarizes the existing knowledge on Paralympic classification and surfing biomechanics. Its primary purpose is to describe the development of an evidence‐based para surfing classification structure that follows the International Paralympic Committee (IPC) Classification Code. Two databases—PubMed and Google Scholar—were searched for three themes: “Paralympic classification”, “performance determining factors in surfing”, and “impact of impairments on surf performance”. The IPC Classification Code and IPC regulations were obtained from the IPC website and official publications. Seventy‐six relevant articles were utilized to guide the design of this preliminary para surfing classification structure. A conceptual framework on athlete characteristics, adaptive sport characteristics, and use of equipment is presented to build the essential knowledge base for continual growth of para surfing. This classification structure and conceptual framework will support para surfing sport expansion and help pave the way for its inclusion in the Paralympic Games.
Transport and co‐transport of carboxylate ions and alcohols in cation exchange membranes
Authors: Kim Jung Min , Beckingham Bryan S. 
Published: July 2021

AbstractUnderstanding multi‐component transport behavior through hydrated dense membranes is of interest for numerous applications. For the particular case of photoelectrochemical CO2 reduction cells (PEC‐CRC), it is important to understand the multi‐component transport behavior of CO2 electrochemical reduction products including mobile carboxylates (formate and acetate) and alcohols (methanol and ethanol) in the ion exchange membranes as one role of the membrane in these devices is to minimize the permeation of these CO2 reduction products to the anolyte as they often oxidize back to CO2. Cation exchange membranes (CEM) are promising candidates for such devices as they act to minimize the permeation of mobile anions, such as carboxylates. However, the design of new CEMs is necessary as the permeation of carboxylates often increases in co‐permeation with alcohols. Here, we investigate the transport behavior of carboxylates and alcohols in two types of CEMs (1) a crosslinked CEM was prepared by free‐radical copolymerization of a sulfonated monomer (AMPS) with a crosslinker (PEGDA), and (2) Nafion® 117. We observe an increase in both PEGDA‐AMPS and Nafion® 117 diffusivities to carboxylates in co‐diffusion with alcohols. We attribute this behavior to charge screening by co‐diffusing alcohol that reduces the electrostatic repulsion between bound sulfonates and mobile carboxylates.