bluuebunny/crossref_metadata_2025 huggingface dataset:
Fantasy Baseball with a Statistical Twist
Authors: Koban Lori , McNelis Erin
Published: January 2021

Fantasy baseball, a game invented in 1980, allows baseball fans to become managers of pretend baseball teams. In most fantasy baseball leagues, participants choose teams consisting of major league players who they believe will do well in five offensive categories (batting average, home runs, runs batted in, stolen bases, and runs scored) or in five pitching categories. We bring a fantasy baseball activity into entry-level statistics classes. Each student drafts a team on the basis of nine offensive categories, most of which are statistical twists on the five categories above. The primary goal of this activity is to apply the material in an introductory one-semester, non-calculus-based college course in statistics. This is the type of course that AP Statistics courses are designed to emulate, so this project is appropriate for AP Statistics classes as well. Indeed, this project incorporates exploratory analysis, planning and conducting a study, probability, and statistical inference, the four major themes of an AP Statistics class (The College Board 2004).
Sound Off! High School Mathematics: Why the Rush?
Authors: Rothery Thomas
Published: January 2021

Hanging up the phone, I rocked all my weight back in my chair, propped my feet on a student desk in my empty classroom, and rubbed my eyes. Certainly, some telephone calls from parents are more frustrating than others. And while I welcome discussion about any concern that a parent has about his or her child, one conversation seems to repeat itself over and over and over.
Connecting Research to Teaching: In Their Own Words: Good Mathematics Teachers in the Era of NCLB
Authors: Hoffman Ellen S. , Caniglia Joanne
Published: January 2021

In her award-winning book The Good High School: Portraits of Character and Culture (1983), Sara Lawrence-Lightfoot chronicles the life and complexities of six high schools across the United States. Through these narratives she tells stories designed to move and persuade. “I believed I could capture the attention of my listeners by conveying what was good about those schools,” she relates. “If we could hear the story better, we'd be in better shape” (cited in de Cuevas 1996).
Storytelling Adds Meaning
Authors: Selby Victor M.
Published: January 2021

Algebra 1 enrichment activities connect mathematics to science and emphasize its role in the history of civilization.
Technology Tips: Constructing and Exploring Pascal's Triangle in TinkerPlots
Authors: MacKinnon Dan
Published: January 2021

TinkerPlotsTM software allows users to engage in data analysis through the construction of graphical representations of data that can be shifted and changed dynamically. Based on its sister program, FathomTM, TinkerPlots takes a constructivist approach to displaying data—that is, users construct, rather than select, types of graphs—thus allowing the creation of a surprising range of charts, tables, graphs, and other mathematical visualizations that fall outside traditional categories.
Delving Deeper: Extending a Classical Geometry Problem
Authors: Kalish Arthur L.
Published: January 2021

In “The Surfer Problem: A ‘Whys’ Approach” (Mathematics Teacher 100, no. 1 [August 2006]: 14–19), Larry Copes and Jeremy Kahan introduced a variety of proofs to one of the classic geometry theorems: The sum of distances from all points in the interior of an equilateral triangle to the three edges is the same. The authors went on to prove that this constant distance is the height of the triangle. Although they presented a range of methods for proving this theorem, I offer one additional method that makes use of a lemma concerning isosceles triangles, introduced below. I will then extend the theorem to points in the exterior of the triangle. Finally, I will replace the equilateral triangle with any regular polygon and show that the revised statement is true.
Parabolas under Pressure
Authors: Madden Seán P.
Published: January 2021

Fountains are one way to introduce students to the mathematics of quadratic equations.
How Sample Size Affects a Sampling Distribution
Authors: Mulekar Madhuri S. , Siegel Murray H.
Published: January 2021

To understand inference, students must understand sampling distributions. Using simulations can help.
Introducing Group Theory through Music
Authors: Johnson Craig M.
Published: January 2021

Concepts in music theory can be used to expose students to interesting examples of abstract notions in higher algebra.
Technology Tips: Multiple Representations Using Dynamic Geometry
Authors: Tamblyn Michael A.
Published: January 2021

The power of The Geometer's Sketchpad® (GSP) for teaching and learning lies in its potential for enabling students to explore geometric concepts and recognize relationships among these concepts as illustrated through the use of multiple representations. This article explores two problems and examines how the use of tables along with GSP sketches may assist students in understanding these concepts. The first activity investigates the relationship of the length of a trapezoid's median (or midsegment) to that of its bases. The second involves showing how the area of a regular polygon approaches that of a circle when the number of sides increases. In both activities, we will start with the geometric object, look at the measurements, tabulate these, and make a graph to illuminate the situation.
The Back Page: Teaching the Pythagorean Theorem for Understanding
Authors: Peterson Blake E.
Published: January 2021

One of my favorite lessons was developed not by me but by a group of student teachers. While conducting research on student teaching in mathematics classes at a Japanese junior high school, I observed a group of seven Japanese student teachers participate in a lesson study to develop a lesson on the Pythagorean theorem. The goal of the lesson was for the students to understand the meaning of the theorem. The student teachers looked in many textbooks, studied the different proofs of the theorem, and consulted their cooperating teachers.
The NCTM High School Curriculum Project: Why It Matters to You
Authors: Martin W. Gary
Published: January 2021

The message of Focus in High School Mathematics: Reasoning and Sense Making, NCTM's new (2009) publication on high school mathematics, is simple: Reasoning and sense making provide a focus for high school mathematics that will give students a foundation for their future success. This focus continues NCTM's emphasis on mathematical processes that stretches back to the central emphasis placed on problem solving in An Agenda for Action (NCTM 1980) and forward to the Process Standards of Principles and Standards for School Mathematics (NCTM 2000).
A Welcome Focus: An Essay Review of the NCTM High School Curriculum Project
Authors: Schoenfeld Alan H.
Published: January 2021

I begin with two stories that encapsulate my view of mathematics teaching and learning. The first, which took place more than forty years ago, is one of my most vivid classroom memories. I was taking an undergraduate probability class. Our textbook was organized in the standard theorem-proof mode: A theorem was stated, the proof was given, and exercises followed. The teacher was about to discuss the next major topic. At the top of the board, she wrote, “The binomial theorem,” followed by (x + y)n =. Then she stopped. She wasn't going to write the statement of the theorem, she said, because people often try to memorize it and get confused. Instead, she was going to show us why the theorem made sense.
Mathematical Lens: Playground Icosahedron
Authors: Ebert Dave
Published: January 2021

In spring 2007, the Lions Club of McFarland, Wisconsin, built a unique playground in Lewis Park that includes the climbing structure seen in photograph 1. This structure is made up of a number of metal bars of the same length that form equilateral triangular regions. The play system was supplied by Lee Recreation in Cambridge, Wisconsin, and built by community volunteers.
Mathematical Lens: Woodstock Revisited
Authors: Zanetti Mary
Published: January 2021

Bethel Woods Center for the Arts is a performing arts venue that includes the Woodstock Festival grounds in Sullivan County, New York. The center is adjacent to the original preserved site where visitors can see the historic field where hundreds of thousands of rock music lovers gathered in August 1969. In addition, they can visit a museum dedicated to the Woodstock experience and the events of the 1960s as well as attend concerts featuring all types of music in various settings.
Mathematical Letter Writing
Authors: Norton Anderson , Rutledge Zachary , Hall Kareston , Norton Rebecca
Published: January 2021

Mathematical letter writing can be a mutually beneficial partnership between high schools and universities.
Contemporary Curriculum Issues: High School to Postsecondary Education: Challenges of Transition
Authors: Hull Susan Hudson , Seeley Cathy L.
Published: January 2021

How can we help prepare our high school students to make the critical transition to what comes after they graduate? We cannot wait until students are seniors to inspire them to consider postsecondary education or training and at the same time prepare them to succeed when they get there.
Activities for Students: Moving a Wall: Using Geometry to Measure an Imperceptible Distance
Authors: Poetzel Adam R. , Hopkins Matthew C. , Muskin Joseph J.
Published: January 2021

Our everyday world seems sturdy. Floors are solid, walls remained fixed. As we go about our daily lives, these solid structures appear securely stationary. But when we look at the world from a different scale—the incredibly small scale of the nanometer (one billionth of a meter)—these solid features are anything but stationary. In this activity, students conduct a mathematical experiment to determine how far they can move a solid wall when they push against it. Intended for use in any geometry or trigonometry classroom, this lesson capitalizes on students' prior knowledge of basic circle properties, right-triangle trigonometry, and unit conversions.
The Back Page: My Favorite Lesson: Making Connections and Communicating Ideas
Authors: McNamee Rick
Published: January 2021

A lesson I use in my second-year algebra classes addresses the NCTM Connections and Communication Standards. These Standards call for lessons that make connections among mathematical ideas and suggest that students use the language of mathematics to communicate their mathematical thinking to peers and teachers.
Media Clips: The High School Weirdness Factor; Green Design
Authors: Lesser Lawrence M. , Warner Aaron J.
Published: January 2021

What measure of variability does the formula in the second panel convey?
Proof in Algebra: Reasoning beyond Examples
Authors: Otten Samuel , Herbel-Eisenmann Beth , Males Lorraine
Published: January 2021

A vignette from an early algebra class reveals a rich opportunity for generating proof before geometry.
The Back Page: My Favorite Lesson: One-to-One in Algebra 1
Authors: Miller Jodie A.
Published: January 2021

My favorite lesson became so only recently. It happened on one of those rare days when you try something new in class, not knowing whether it will work, and your students seem to reach such a deep understanding that you say, “This is what I became a teacher for!”
Media Clips: Fence Building/Composting
Authors: Robinson Bonnie
Published: January 2021

Not every fence is on flat ground, and different types of fences handle slopes differently. Some of them, like a simple vertical board fence, easily take slopes in stride. Stringers that follow the slope are attached to the posts. The position of each individual board is adjusted as it is attached to the stringers so the fence just flows down the slope. But fences with discrete rectangular panels like ours must “stairstep” down the slope. This fence will easily accommodate a slope that drops no more than 12 [inches] between posts. Once your posts are set, the five-step drawing … shows you how to mark your posts at the proper height and where to position the fence panels.
Sound Off!: One Mathematics Teacher's Thoughts on Assessment
Authors: Lawrance Harold I.
Published: January 2021

Writing and administering tests was one of the things I loved most during my fifteen years of teaching. My interest in the assessment process was spurred in part by how much importance my students seemed to place on my assessments, and this emphasis in turn motivated me to write fair and accurate assessments.
Alternative Approaches to Traditional Topics in Algebra
Authors: Coburn John W.
Published: January 2021

These new approaches to algebra, although atypical, can bring unreachable students into the classroom mix.
Media Clips: Top-Dollar Musicians / When Is 10 Not Equal to Ten?
Authors: Cibes Margaret , Greenwood Jim
Published: January 2021

Organize the data in the clip in the form of a table. Before making a scatter plot of the data, determine which of the two data sets would be more likely to be the independent variable and which the dependent variable. Explain your answer. Then construct the scatter plot.
Historical Reflections on Teaching Trigonometry
Authors: Bressoud David M.
Published: January 2021

Returning to the beginnings of trigonometry—the circle—has implications for how we teach it.
Seeing the Potential in Students' Questions
Authors: Cavey Laurie O. , Mahavier W. Ted
Published: January 2021

Responding to students' questions is a critical part of teaching mathematics (Cavey, Whitenack, and Lovin 2006; NCTM 1991; Schifter 1996). A particular response may either stifle a student's inquiry or, ideally, stimulate his or her interest in mathematics. Although formulating responses that have the potential to engage students in developing new mathematical insights is challenging, we believe that this skill can be developed. We have found it helpful to view this challenge as a matter of recognizing the mathematics of a student's question—that is, the mathematics the student understands as well as the mathematics he or she may be ready to learn
Mathematics of Information Processing and the Internet
Authors: Hart Eric W.
Published: January 2021

Access, security, accuracy, and efficiency—all twenty-first-century high school mathematics curricula should contain content relating to these four fundamental themes.
Teaching Proportional Reasoning through Familiar Biology
Authors: Burger Lance
Published: January 2021

Exploring relationships between size and heat loss in dogs teaches students about the ratio of surface area to volume.
Activities for Students: Introduction to Graphing: Connecting the Dots from Geometry to Botany
Authors: Jaqua Kathy M. C.
Published: January 2021

When I was a small child, one way that my mother kept me occupied was with dot-to-dot books. In these books, I connected the dots, in numerical or alphabetical order, to create a picture. I was always amazed that what appeared to be nothing but a collection of dots at the beginning would make an image, and I tried to visualize that image before drawing any lines. Now I find that the opposite process—starting with a picture and then connecting the dots—is a great way to help students enjoy mastering graphing in a coordinate plane. The botanical twist is a bonus.
The Back Page: My Favorite Lesson: Functions, Functions Everywhere
Authors: Nabb Keith A.
Published: January 2021

All mathematics educators would probably rank the function concept as one of the most important ideas in contemporary mathematics. Even so, teaching something to the tune of “for each element in the first set, there is precisely one element in the second set” invites some well-deserved criticism from our students. Surely, such a mainstay of the mathematics curriculum deserves a far warmer introduction.
Using Dynamic Technology to present concepts through Multiple Representations
Authors: DePeau Edward A. , Kalder Robin S.
Published: January 2021

The TI-Nspire combines many different capabilities of many technologies—The Geometer's Sketchpad, Microsoft Word, and Excel—in one tool.
Media Clips: Mattel Court Case / Zimbabwe Removes 12 Zeros from Currency
Authors: Hall Randy
Published: January 2021

A jury in California awarded Mattel Inc. $100 million US in damages on Tuesday in a federal copyright lawsuit that pitted the house of Barbie against MGA Entertainment Inc., the maker of the saucy Bratz dolls….
Cell Phones and Sun Shadows: Exploring the Equation of Time
Authors: Madden Seán P.
Published: January 2021

Students use cell phones and graphing calculators to model the differences between solar and clock time.
The Back Page: My Favorite Lesson: Chess Piece(wise) Project
Authors: Garvey Daniel
Published: January 2021

One of my favorite lessons is a project I call Chess Piece(wise). I give this project to my precalculus students after we have discussed domain and range and piecewise-defined functions. Referring to the game of chess and using manipulatives (chessboards and chess pieces) tend to “hook” students. The project challenges them to define piecewise models symbolically, numerically, and graphically and to determine the domain and range of those models. Moreover, students model something that is real and not typically modeled in a mathematics course.
Connecting Research to Teaching: Why Did You Do That?
Authors: Chazan Daniel , Sandow Dara
Published: January 2021

Secondary school mathematics teachers are often exhorted to incorporate reasoning into all mathematics courses. However, many feel that a focus on reasoning is easier to develop in geometry than in other courses. This article explores ways in which reasoning might naturally arise when solving equations in algebra courses.
Sound Off! – Mathematics vs. MTV: How to Win the Eyeball War
Authors: Wulsin H. Wells
Published: January 2021

“Sound Off!” is the Mathematics Teacher's op–ed page; as such, the opinions expressed reflect those of the author and not necessarily those of the MT Editorial Panel or of the National Council of Teachers of Mathematics. Readers are encouraged to respond to this “Sound Off!” by submitting letters to the “Reader Reflections” section of the journal as well as to submit essays for consideration as “Sound Off!”s. Please visit http://www.nctm.org/publications/content aspx?id=10440#soundoff for information.
Learning to Map and Mapping to Learn Our Students' Worlds
Authors: Rubel Laurie H. , Chu Haiwen , Shookhoff Lauren
Published: January 2021

Maps at four levels of scale—global, national, regional, and local—provide a context for mathematical investigations that help teachers learn about their students.
Do It Right – Strategies for Implementing Technology
Authors: Campe Karen D.
Published: January 2021

Mathematics teachers can use a broad range of technologies—calculators, computers, display systems, and others—as teaching and learning tools. Although actual access is influenced by budgets and demand, the important thing is to make the best use of the technology available. Whether you have one computer station for demonstration, a classroom set of graphing calculators, or a fully wired classroom, you can take steps to make your technology implementation most effective and successful.
Proofs without Words: A Visual Application of Reasoning and Proof
Authors: Bell Carol J.
Published: January 2021

Reasoning and Proof is one of the process standards set forth in NCTM's principles and standards for school mathematics (2000).
Delving Deeper: Deepening Understanding of Transformation through Proof
Authors: Bucher Christopher J. , Edwards Michael Todd
Published: January 2021

In the introductory geometry courses that we teach, students spend significant time proving geometric results. Students who conclude that angles are congruent because “they look that way” are reminded that visual information fails to provide conclusive mathematical evidence. Likewise, numerous examples suggesting a particular result should be viewed with skepticism. After all, unfore–seen counterexamples render seemingly valid conclusions false. Inductive reasoning, although useful for generating conjectures, does not replace proof as a means of verification.
Technology Tips: April 2003
Authors: Gosse Paul , Hollebrands Karen Flanagan
Published: January 2021

This month's tip centers on an alternative view of functions. Instead of perpendicular axes for domain and range, we explore parallel axes. This idea has been around for a while (see the references in Bridger and Bridger ([2001] and in the “Surfing Note”), but we hope to breathe new life into this fascinating representation of functions with two easy-to-use programs for the TI-83 Plus. We provide an introduction to mapping diagrams (also called function diagrams) and the code for one program to produce them using the TI-83 Plus. Information about the second program will be given in “Technology Tips” in May. Both programs are available electronically, so users do not have to type the programs into their calculators.
Activities for Students: Using Graphing Calculators to Model Real-World Data
Authors: Holliday Berchie W. , Duff Lauren R.
Published: January 2021

Mathematics teachers understand that calculators have revolutionized the teaching of secondary school mathematics. After students have demonstrated their abilities to perform such computations without calculators, calculators can free students and teachers from performing redundant computations. Graphing calculators, in particular, free students from computing dependent values needed to construct line graphs, for example. But one problem is how to teach students to use a graphing calculator to plot, calculate, and graph linear equations of best fit from realworld data. Another problem is getting students to engage in the task and construct an increasingly useful conceptualization of linear modeling. In the beginning, teachers should, perhaps, provide direct instruction, followed by modeling how to enter and graph data sets efficiently.
Conceitos de ecologia aplicada: bases da biodiversidade
Authors: Silva Cleber Vinicius Vitorio da , Lenz Elenice Rachid da Silva , Lima Evandro , Lins Gustavo Aveiro , Almeida Josimar Ribeiro de , Aguiar Lais Alencar de , Garcia Pauli Adriano de Almada , Pereira Raphael do Couto , Garcia Vanessa da Silva
Published: January 2021

Embora todos os sistemas sejam cadeias com elos de força variável, também acontece de alguns sistemas naturais se desintegrarem com maior facilidade que outros, com uma rápida e irreversível modificação em seu todo. A atividade humana agora afeta todas as regiões da Terra (nenhum refúgio, nem mesmo no mais profundo abismo oceânico, existe mais em estado primitivo natural), assim mais e mais espécies estão suscetíveis à extinção. Muitas desaparecerão antes mesmo de tornarem-se conhecidas pela ciência. Algumas carregarão para sua tumba recursos energéticos valiosos e insubstituíveis.
LUMINESCENT PROPERTIES OF TERBIUM WITH S- (4-BROMANILIDE) METHYL ETHER OF SULFOSALICYLIC ACID
Authors: Elcheparova Svetlana A. , Kokoeva Aneta A. , Tatrokova Inna A.
Published: January 2021

It was of interest to search for luminescent reactions to terbium in complexes with sulfosalicylic acid derivatives and to strengthen them by studying the influence of the third components (aminopolycarboxylic acids, organic bases, and surfactants). Absorption spectra of solutions of rare earth element complexes in the wavelength range of 220-880 nm were recorded using the SF-26 spectrophotometer. To obtain the maximum luminescence of the luminescent reaction of rare earth elements in complexes with organic reagents, a number of factors that have a significant impact on the intensity of solutions of luminescent complexes have been studied. Such factors are the pH of the complexes, concentration of reagent, time of maturation complexes, the irradiation time, the order of adding the reagents and the ionic strength of the solutions. According to studies conducted, surfactants increase the luminosity of terbium ions in complexes with sulfosalicylic acid derivatives. As a surfactant, decylpyridinium chloride was used in solutions. The existence of a bright luminescent green reaction of terbium in a complex with methyl ester S- (4-bromanilide) sulfosalicylic acid was established. The optimal conditions for the complexation of terbium were selected and highly sensitive luminescent methods for determining terbium in various objects were developed. Terbium is converted into a luminescent complex compound with an organic reagent S- (4-bromanililide) sulfosalicylic acid methyl ester in the presence of a cationic surfactant decylpyridinium chloride in a ratio of 1: 2: 13, pH 7.9 ± 0.08. The resulting complex compound of terbium upon irradiation with a mercury lamp under ultraviolet light gives intense green luminescence that is stable during standing and irradiation. As a consequence, the proposed method allows to determine terbium in the oxides of rare earth elements, which are quenchers of luminescence with a sensitivity of 10-8%, bypassing the extraction stage. The sensitivity of the determination of terbium in the oxides of the remaining lanthanides is 2.4·10-10%.
MODIFICATION OF CHITOSAN BY THIOUREA DIOXIDE
Authors: Naidenko Ekaterina V. , Makarov Sergei V. , Pokrovskaya Elizaveta A. , Nikulin Anton M.
Published: January 2021

Thiourea dioxide (TDO, aminoiminomethanesulfinic acid, formamidinesulfinic acid) was used for the chemical modification of chitosan. The interaction of TDO with chitosan in the presence of alkali results in the guanidinylated chitosan, the substitution degree is 0.25-0.27 and does not depend largely on molar ratio of thiourea dioxide to chitosan. The structure of modified chitosan has been proved using UV and IR spectroscopy as well as elemental analysis. It is shown that modification of chitosan proceeds under mild conditions. Contrary to chitosan, its guanidinylated derivative has biocidal properties against Gram-positive and Gram-negative bacteria in the aqueous solutions close to neutral (pH 6.2). It can be explained by the partial substitution of amino groups by guanidine groups existing predominantly in the protonated form in the neutral aqueous solutions. The system thiourea dioxide-hydrogen peroxide was used for the oxidative modification of chitosan. It is shown that thiourea dioxide and hydrogen peroxide separately do not oxidize chitosan but in the presence of their mixture the formation of carboxylic groups in chitosan has been observed. The quantity of carboxylic groups in the modified and native chitosan has been determined by the titration with sodium hydroxide. The presence of carboxylic groups has been proved also using IR spectroscopy. It is shown that the quantity of carboxylic groups increases with the increase of the ratio [TDO]/[chitosan].
A Case of Trisomy 9 Mosaicism Confirmed by Microarray Test
Authors: Chang-Eon Park , Mi-Lm Chung , Ji-Hye Hwang , Min-Kyeong Lee
Published: January 2021

Trisomy 9 mosaicism syndrome is a rare chromosomal abnormality with a high incidence of natural abortion and perinatal death. This syndrome is characterized by intrauterine growth retardation, mental retardation, craniofacial dysmorphism including a prominent nasal bridge with a short root and a fish-shaped mouth with thin lips, skeletal abnormalities, congenital heart defects, and genital abnormalities. The incidence and severity of malformations depend on the percentage of trisomic cells in the different tissues. We report a neonate who had the characteristic features of trisomy 9 syndrome with dysmorphic features including micrognathia, microcephaly, a low-set and malformed ear, a prominent lip, and cardiac defect. No chromosomal abnormalities were detected on a routine peripheral blood chromosomal analysis; however, a chromosomal abnormality with trisomy 9 mosaicism (low-level mosaic type) was detected on genetic tests. This is thought to be due to the low proportion of trisomic cells, and for this reason, the patient in this case shows a better prognosis than four patients previously reported in Korea, they were all diagnosed by peripheral blood chromosome testing.
Subcapsular Hepatic Hematoma after Cardiopulmonary Resuscitation
Authors: Lee Song-I
Published: January 2021

Cardiopulmonary resuscitation (CPR) is an important life-saving procedure in emergency care. However, CPR is associated with various complications. A 41-year-old man was admitted to the intensive care unit after CPR. A sudden decrease in the blood pressure and hematocrit level was recorded. An abdominal computed tomography (CT) showed a large subcapsular hematoma in the left lobe of the liver. With conservative treatment, the hematoma reduced in size, but it was later managed with percutaneous drainage. The patient recovered and was discharged. We obtained a favorable outcome with conservative, nonsurgical treatment. Subcapsular hepatic hematoma is a potential life-threatening complication that should be considered in CPR survivors.
Reseña de M.ª Carme Jonyent Figueras y Pere Comellas Casanova: Antropología lingüística. Madrid: Editorial Síntesis (2019), 235 páginas. ISBN: 978-84-9171-431-6.
Authors: Aguilar Ruiz Manuel José
Published: January 2021

El objetivo que pretende el breve manual aquí reseñado, como indica su misma «Introducción», es el de ofrecer una aproximación a la disciplina que conocemos como antropología lingüística con la que, partiendo de los procedimientos y métodos clásicos de estudio de esta disciplina, se entienda cómo es posible establecer una relación entre lenguas y culturas (bajo concepciones tradicionales o, según las perspectivas más actuales, entre lo lingüístico y lo extralingüístico). De este modo, el libro pretende ser «una introducción al fascinante mundo de las lenguas y sus relaciones con las culturas, tan distintas y al mismo tiempo tan iguales en la medida en que se trata de manifestaciones de una misma cara, la humana.
A Multidimensional Approach to Competitiveness, Innovation and Well-Being in the EU Using Canonical Correlation Analysis
Authors: Androniceanu Ane-Mari , Kinnunen Jani , Georgescu Irina , Androniceanu Armenia
Published: January 2021

Achieving a competitive economy and a competitive market generally proceeds from the desire to meet economic and social objectives and it ensures a growing level of social welfare. The objectives of our research are to determine and highlight the bidirectional linear correlations among competitiveness, well-being and innovation and to analyze the main factors that influence these relations. Our research includes the EU member states and the UK using these countries’ specific indicators from the databases of EUROSTAT, the World Economic Forum and the United Nations from 2016-2018. We used Canonical Correlation Analysis to determine a set of canonical variates which represent linear combinations of the variables from each set. The contributions of our research show a direct and strong link among the three pillars of competitiveness, innovation and well-being. This analysis allowed us to identify and analyze the influence of innovation on the economic development and competitiveness of each EU country and on the well-being of its population. Governments and organizations that invest more in research in terms of innovation to increase the competitiveness of their products and services have shown a growing GDP and a higher level of population well-being. This research is representative at the European level and may influence the decisions of national governments and other institutions to encourage innovation through drivers such as R&D expenditures and human resources as the main factors generating economic growth and competitiveness, thus with a direct effect on GDP and on well-being.
Zero-dimensional numerical simulation of dry reforming of methane in atmospheric pressure non-equilibrium plasma
Authors: Zhong Wang-Shen , Chen Ye-Li , Qian Mu-Yang , Liu San-Qiu , Zhang Jia-Liang , Wang De-Zhen ,   Department of Physics, Nanchang University, Nanchang 330031, China,   School of Physics, Dalian University of Technology, Dalian 116024, China
Published: January 2021

Recently, atmospheric non-equilibrium plasma has been proposed as a potential and novel type of “reaction carrier” for the activation and conversion of greenhouse gases (methane and carbon dioxide) into value-added chemicals, due to its unique non-equilibrium characteristics. In this paper, a zero-dimensional plasma chemical reaction kinetic model in CH4/CO2 gas mixture is constructed, with an emphasis on reaction mechanism for plasma dry reforming of methane to syngas and oxygenates. Especially, the effect of the CH4 molar fraction (5%–95%) on plasma dry reforming of methane is investigated. First, the time evolution of electron temperature and density with initial methane content is presented, and the results show that both the electron temperature and electron density vary periodically with the applied triangular power density pulse, and the higher initial methane content in gas mixture is favored for a larger electron temperature and density. Subsequently, the time evolution of number densities of free radicals, ions and molecules at different CH4/CO2 molar fraction are given. The higher the initial methane content, the greater the number densities of H, H–, H2, and CH3, leading to insufficient oxygen atoms to participate in the reaction for oxygenates synthesis. The conversions of inlet gases, the selectivities of syngas and important oxygenates are also calculated. The conversion rate of carbon dioxide increases with the increasing methane content, but the conversion rate of methane is insensitive to the variation of methane content. As methane mole fraction is increased from 5% to 95%, the selectivities of important oxygenates (CH3OH and CH2O) are relatively low (<5%), and the selectivity of H2 gradually increases from 13.0% to 24.6%, while the selectivity of CO significantly decreases from 58.9% to 9.7%. Moreover, the dominant reaction pathways governing production and destruction of H2, CO, CH2O and CH3OH are determined, and CH3 and OH radicals are found to be the key intermediate for the production of valuable oxygenates. Finally, a schematic overview of the transformation relationship between dominant plasma species is summarized and shown to clearly reveal intrinsic reaction mechanism of dry reforming of methane in atmospheric non-equilibrium plasma.
Design and simulation of Mg2Si/Si avalanche photodiode
Authors: Wang Ao-Shuang , Xiao Qing-Quan , Chen Hao , He An-Na , Qin Ming-Zhe , Xie Quan ,   Institute of Advanced Optoelectronic Materials and Technology, College of Big Data and Information Engineering, Guizhou University, Guiyang 550025, China
Published: January 2021

InGaAs and HgCdTe materials are widely used in short wave infrared photodetectors, which contain heavy metal elements. The massive use of the heavy metal elements naturally results in their scarcity, and the nonnegligible environmental pollution. Searching for other suitable materials for infrared devices becomes a key to solving the above problems. As a kind of abundant and eco-friendly material, Mg2Si has a high absorption coefficient in the near-infrared band. Its application in infrared detector makes it possible to replace the infrared devices containing toxic elements on the market in the future. The Mg2Si/Si avalanche photodiode(APD) with separation structure of absorption layer, charge layer and multiplication layer, with Mg2Si serving as the absorption layer, is constructed by using the Atlas module in Silvaco software. The effects of the thickness and doping concentration of the charge layer and multiplier layer on the distribution of internal electric field, punch-through voltage, breakdown voltage (Vb), C-V characteristics, and transient response of Mg2Si/Si SACM-APD are simulated. The effects of bias voltage on the I-V characteristics and spectral response are analyzed. The punch-through voltage, breakdown voltage, dark current density, gain coefficient (Mn) and the current amplification factor (M) after avalanche effect of APD are obtained after the structure optimization. According to the simulation results, the spectral response wavelength of the device is extended to 1.6 μm, so the selection of Mg2Si as the absorption layer effectively extends the spectral response band of Si based APD. When the wavelength of incident light is 1.31 µm and the optical power is 10 mW/cm2, the obtained punch-through voltage is 17.5 V, and the breakdown voltage is 50 V. When the bias voltage is 47.5 V (0.95Vb), the peak value of spectral response is 25 A/W at a wavelength of 1.1 μm, a density of dark current is about 3.6 × 10–5 A/cm2, a multiplication factor Mn is 19.6, and Mn achieves a maximum value of 102 when the device is broken down. Meanwhile, the current amplification factor M after avalanche effect is 75.4, and the current gain effect of the SACM structure is obvious. The peak value of spectral response for the pin-type photodiode in the previous study is only 0.742 A/W. Comparing with the pin-type photodiode, the spectral response of Mg2Si/Si SACM-APD is greatly improved. In this work, the structure parameters of the device are optimized, which lays a nice foundation for fabricating the high-performance devices.
Use of signals of positive and negative selection to distinguish cancer genes and passenger genes
Authors: Bányai László , Trexler Maria , Kerekes Krisztina , Csuka Orsolya , Patthy László
Published: January 2021

A major goal of cancer genomics is to identify all genes that play critical roles in carcinogenesis. Most approaches focused on genes positively selected for mutations that drive carcinogenesis and neglected the role of negative selection. Some studies have actually concluded that negative selection has no role in cancer evolution. We have re-examined the role of negative selection in tumor evolution through the analysis of the patterns of somatic mutations affecting the coding sequences of human genes. Our analyses have confirmed that tumor suppressor genes are positively selected for inactivating mutations, oncogenes, however, were found to display signals of both negative selection for inactivating mutations and positive selection for activating mutations. Significantly, we have identified numerous human genes that show signs of strong negative selection during tumor evolution, suggesting that their functional integrity is essential for the growth and survival of tumor cells.
A survey of early-career researchers in Australia
Authors: Christian Katherine , Johnstone Carolyn , Larkins Jo-ann , Wright Wendy , Doran Michael R
Published: January 2021

Early-career researchers (ECRs) make up a large portion of the academic workforce and their experiences often reflect the wider culture of the research system. Here we surveyed 658 ECRs working in Australia to better understand the needs and challenges faced by this community. Although most respondents indicated a ‘love of science’, many also expressed an intention to leave their research position. The responses highlight how job insecurity, workplace culture, mentorship and ‘questionable research practices’ are impacting the job satisfaction of ECRs and potentially compromising science in Australia. We also make recommendations for addressing some of these concerns.
Selfing is the safest sex for Caenorhabditis tropicalis
Authors: Noble Luke M , Yuen John , Stevens Lewis , Moya Nicolas , Persaud Riaad , Moscatelli Marc , Jackson Jacqueline L , Zhang Gaotian , Chitrakar Rojin , Baugh L Ryan , Braendle Christian , Andersen Erik C , Seidel Hannah S , Rockman Matthew V
Published: January 2021

Mating systems have profound effects on genetic diversity and compatibility. The convergent evolution of self-fertilization in threeCaenorhabditisspecies provides a powerful lens to examine causes and consequences of mating system transitions. Among the selfers,Caenorhabditis tropicalisis the least genetically diverse and most afflicted by outbreeding depression. We generated a chromosomal-scale genome forC. tropicalisand surveyed global diversity. Population structure is very strong, and islands of extreme divergence punctuate a genomic background that is highly homogeneous around the globe. Outbreeding depression in the laboratory is caused largely by multiple Medea-like elements, genetically consistent with maternal toxin/zygotic antidote systems. Loci with Medea activity harbor novel and duplicated genes, and their activity is modified by mito-nuclear background. Segregating Medea elements dramatically reduce fitness, and simulations show that selfing limits their spread. Frequent selfing inC. tropicalismay therefore be a strategy to avoid Medea-mediated outbreeding depression.
Stochastic asymmetric repartition of lytic machinery in dividing CD8+ T cells generates heterogeneous killing behavior
Authors: Lafouresse Fanny , Jugele Romain , Müller Sabina , Doineau Marine , Duplan-Eche Valérie , Espinosa Eric , Puisségur Marie-Pierre , Gadat Sébastien , Valitutti Salvatore
Published: January 2021

Cytotoxic immune cells are endowed with a high degree of heterogeneity in their lytic function, but how this heterogeneity is generated is still an open question. We therefore investigated if human CD8+ T cells could segregate their lytic components during telophase, using imaging flow cytometry, confocal microscopy, and live-cell imaging. We show that CD107a+-intracellular vesicles, perforin, and granzyme B unevenly segregate in a constant fraction of telophasic cells during each division round. Mathematical modeling posits that unequal lytic molecule inheritance by daughter cells results from the random distribution of lytic granules on the two sides of the cleavage furrow. Finally, we establish that the level of lytic compartment in individual cytotoxic T lymphocyte (CTL) dictates CTL killing capacity.
A rapid whisker-based decision underlying skilled locomotion in mice
Authors: Warren Richard A , Zhang Qianyun , Hoffman Judah R , Li Edward Y , Hong Y Kate , Bruno Randy M , Sawtell Nathaniel B
Published: January 2021

Skilled motor behavior requires rapidly integrating external sensory input with information about internal state to decide which movements to make next. Using machine learning approaches for high-resolution kinematic analysis, we uncover the logic of a rapid decision underlying sensory-guided locomotion in mice. After detecting obstacles with their whiskers mice select distinct kinematic strategies depending on a whisker-derived estimate of obstacle location together with the position and velocity of their body. Although mice rely on whiskers for obstacle avoidance, lesions of primary whisker sensory cortex had minimal impact. While motor cortex manipulations affected the execution of the chosen strategy, the decision-making process remained largely intact. These results highlight the potential of machine learning for reductionist analysis of naturalistic behaviors and provide a case in which subcortical brain structures appear sufficient for mediating a relatively sophisticated sensorimotor decision.
A fungal member of the Arabidopsis thaliana phyllosphere antagonizes Albugo laibachii via a GH25 lysozyme
Authors: Eitzen Katharina , Sengupta Priyamedha , Kroll Samuel , Kemen Eric , Doehlemann Gunther
Published: January 2021

Plants are not only challenged by pathogenic organisms but also colonized by commensal microbes. The network of interactions these microbes establish with their host and among each other is suggested to contribute to the immune responses of plants against pathogens. In wild Arabidopsis thaliana populations, the oomycete pathogen Albugo laibachii plays an influential role in structuring the leaf phyllosphere. We show that the epiphytic yeast Moesziomyces bullatus ex Albugo on Arabidopsis, a close relative of pathogenic smut fungi, is an antagonistic member of the A. thaliana phyllosphere, which reduces infection of A. thaliana by A. laibachii. Combination of transcriptomics, reverse genetics, and protein characterization identified a GH25 hydrolase with lysozyme activity as a major effector of this microbial antagonism. Our findings broaden the understanding of microbial interactions within the phyllosphere, provide insights into the evolution of epiphytic basidiomycete yeasts, and pave the way for novel biocontrol strategies.
Associations between self-reported and objective face recognition abilities are only evident in above- and below-average recognisers
Authors: Estudillo Alejandro J. , Wong Hoo Keat
Published: January 2021

The 20-Item Prosopagnosia Items (PI-20) was recently introduced as a self-report measure of face recognition abilities and as an instrument to help the diagnosis of prosopagnosia. In general, studies using this questionnaire have shown that observers have moderate to strong insights into their face recognition abilities. However, it remains unknown whether these insights are equivalent for the whole range of face recognition abilities. The present study investigates this issue using the Mandarin version of the PI-20 and the Cambridge Face Memory Test Chinese (CFMT-Chinese). Our results showed a moderate negative association between the PI-20 and the CFMT-Chinese. However, this association was driven by people with low and high face recognition ability, but absent in people within the typical range of face recognition performance. The implications of these results for the study of individual differences and the diagnosis of prosopagnosia are discussed.
Nurses’ Experiences of Managing Cardiopulmonary Resuscitation: A Qualitative Study
Authors: Nayeri Nahid Dehghan , Senmar Mojtaba , Ghobadi Amir
Published: January 2021

Introduction: Cardiac arrest is one of the leading causes of death. Nurses are often the first members of the healthcare teams to deal with these patients. The management of how nurses performing resuscitation has drawn a lot of attention. Aim: The present study was conducted with an aim of determining nurses’ experiences of managing Cardiopulmonary Resuscitation (CPR). Materials and Methods: This qualitative study was conducted using the content analysis approach. Fourteen nurses with different positions and active roles in the CPR were selected purposefully. Data were collected through semi-structured interviews from July to December 2019. Data were analysed based on the Graneheim and Lundman’s approach. Guba and Lincoln’s trustworthiness criteria were used to obtain the trustworthiness of data. Results: Fourteen Nurses, with mean age of 32.14±4.34 years and mean work experience of 9.78±4.50 years were included in the study. Four main categories and fourteen subcategories were recognised in the questionnaire, including the role of human resources (fluctuation of coordination and cooperation, capability and motivation), management of procedures (cardiac massage, shock, airway, drug therapy, and vascular access), role of context and structure (equipment and physical space, contextual factors, and losing time) and the role of law and ethics (guideline, reporting and evaluation, and power of conscience). Conclusion: This study showed that nurses face various challenges and limitations at the beginning, during and after resuscitation in the management of CPR. Therefore, nurses’ ability to manage and execute this process should be enhanced.