bluuebunny/crossref_metadata_2025 huggingface dataset:
Nine Out of Ten Like Consumer Credit Problems
Authors: Foster LeBaron R.
Published: January 2021

In all schools, Iarge or small in size, high or low in rating, recent tests show that much of the knowledge that teachers pour on students does not soak in. It rolls off students as water rolls off a duck's back. I should say, as water used to roll off a duck's back. Chemists recently discovered a substance, Aerosol OT, which breaks up the surface tension of water molecules. When a duck is shampooed with this chemical, he loses his floating power. With piteous loss of dignity, he sinks. This is because Aerosol removes the protective oils from the feathers, allowing water to penetrate. What we need is an Aerosol which, when poured over students, breaks down their resistance and allows ideas to penetrate.
Three Major Difficulties in the Learning of Demonstrative Geometry
Authors: Smith Rolland R.
Published: January 2021

Efficient and successful teaching of demonstrative geometry in the senior high school requires on the part of the teacher much more than a knowledge of the subject matter. The young person who goes into the geometry classroom after leaving college with honors in mathematics is not necessarily a good teacher. Unless he has been forewarned in one way or another, he is likely to resort to the lecture method which his professors have used in college and then find to his surprise that his pupils have learned little. He may have taken courses in which he studied the general laws of learning as applied to pupils of high school age, but even so he will have difficulty in translating his knowledge to fit the specific requirements of the classroom. Part of his training may have been to observe the work of a highly efficient, successful, and artistic teacher whom he may try to imitate. He will find, however, that he has not been keen enough to grasp the meaning and purpose of many of the techniques. Not knowing beforehand how a group of pupils will react to a given situation, he fails to see when and how the experienced teacher has avoided pitfalls by introducing many details of development not necessarily needed in the finished product but indispensable to the learning process. Before he can become adept in preparing a course of study or planning his everyday lessons, he needs to know what difficulties pupils will have with the many component tasks which when integrated fulfill the desired aim. A teacher can plan a skillful development only when he has reached a point where he can predict within reasonable limits what the reactions of a group of pupils will be.
The Sixth Summer Meeting of The National Council of Teachers of Mathematics
Authors: Schreiber Edwin W.
Published: January 2021

The Sixth Summer Meeting of the National Council of Teachers of Mathematics was held at Milwaukee, Wisconsin, July 1, 2, and 3, 1940, with headquarters at the Hotel Pfister. Some 350 were in attendance at this meeting and 338 registered.
The Use of Graded Originals in Plane Geometry
Authors: Lane Ruth
Published: January 2021

Though there is a definite trend toward the provision for individual differences within a class, in general, such provisions made in geometry have been based largely upon the idea of extra credit rather than upon differentiation in the materials used. Where such differentiation has been made, the materials provided for the gifted pupil are often more difficult than the rest, but, this pupil must first do all, or at least part of the work done by the poorest students in tho class. Thus the more able pupil is expected to do both more originals and harder originals than the rest of the class.
The Present Situation in Secondary Mathematics, with Particular Reference to the New National Reports on the Place of Mathematics in Education
Authors: Betz William
Published: January 2021

Introduction. The subject chosen for this discussion presents so many different aspects that it seemed necessary to agree at the outset on certain limitations of its potential scope.
Some Suggestions to Readers of Two Recent Reports on the Mathematics Curriculum
Authors: Hartung Maurice L.
Published: January 2021

One who makes a survey of the literature relating to mathematical education is likely to experience several different sorts of reactions. He may, for example, note that the leaders of a generation ago frequently recommended types of procedure and content which have become common only recently or are still seldom used. If he believes such recommendations are good and in line with modern views, he may develop a feeling of discouragement. The forward movement of reform seems to be a tortoise-like crawl, interrupted by periods of somnolence, by backtracking, and by detours. On the other hand, as he compares the practices of the past with those of the present, he may decide that great progress has been made. Mathematical instruction in many schools today is vastly different from what it was twenty or thirty years ago. Moreover, it seems that at the present we are in the midst of a period of relatively rapid change and reorganization. Whether or not the changes which are being made are desirable is a matter of opinion, but that they are taking place can easily be established.
Training Teachers of Junior College for Relational Thinking
Authors: Georges J. S.
Published: January 2021

The art of thinking is not essential to living, but is extremely essential to human living. Reflective thinking, as distinguished from idle reverie, is relevant thinking. Relevant thinking is thinking in terms of the entities that are relevant factors of the problem or situation, the properties of these entities, that are relevant to the particular situation, and the relationships between these entities and their properties that bear upon the situation.
Statistics for Ninth Grade Pupils
Authors: Drake Richard M.
Published: January 2021

During a period of six years the writer has attempted to develop a unit of instruction based upon statistical concepts. This project was carried on at the University of Minnesota High School with ninth-grade mathematics pupils. Since many teachers have evinced an interest in the procedure employed, it was deemed advisable to put in written form the objectives and teaching methods utilized.
What is Happening to College-Preparatory Mathematics?
Authors: Bacon H. M.
Published: January 2021

A serious problem confronts teachers of mathematics in preparing students for an engineering education.
Mathematics in the Defense Program
Authors: Morse Marston , Hart William L.
Published: January 2021

The American Mathematical Society and the Mathematical Association of America number some 5000 members. The American Mathematical Society is devoted primarily to the development of research in mathematics, and the Mathematical Association of America to the teaching of mathematics. About a year ago these societies appointed a committee known as the War Preparedness Committee, to prepare the two societies to be useful to our nation in time of war. The ways and means of doing this were not prescribed, but were left to the committee. Before I give you details about our organization and aims it will be helpful to make a few remarks concerning the role of science in defense in general.
Correlation of Solid Geometry with Other Subjects
Authors: Refior Sophia R.
Published: January 2021

We are faced with the same problem which confronts most public schools, namely of adapting our teaching to pupils of varying ability. Some students are well prepared and gifted mentally so they can readily visualize the various figures, while others seem to have only a minimum of imagination. This disparagement is evident in Plane Geometry but is more apparent in Solid Geometry. Three-dimensional figures on two-dimensional surfaces are conundrums which remain mysteries. These pupils who lack the power of imagination and abstraction often have mechanical ability. They wish to enter professions where they can use their deftness and they realize their need for more of the theories of solid geometry.
Individual Differences and Course Revision in Plane Geometry
Authors: Lynch James M.
Published: January 2021

Few topics are of more concern to geometry teachers at the present time than the changed character of the student body that has come to them during the past ten years. Traditional college-preparatory students no longer represent a majority of the high school enrollment. Instead there is a preponderance of those students who, in the days prior to the depression, would have dropped out of school.
The Double Track Plan of High School Mathematics
Authors: Douglass Harl R.
Published: January 2021

The prevailing high school curriculum in mathematics was formulated very much much as it now exists in the quarter century immediately following the Civil War—1865-1890. In 1890 there were about 250,000 boys and girls in high school—about one in ten of all youth of high school age. Less than three percent of young people were graduating from high school between 1880 and 1890. High schools were almost always looked upon as “prep” schools for “getting” the “bright boys” ready for college. The present high school curriculum in high school mathematics was built for those few who went on—the alber pupils, the college preparatory pupil, the future engineer, physicist, and teacher.
The Responsibility of the Mathematics Teacher in Curriculum Building
Authors: Foust Judson W.
Published: January 2021

For some time two important activities have been attracting the attention of mathematics teachers. The first is the criticism of mathematics, both constructive and destructive. This criticism has come from within the ranks of mathematicians as well as from without. It has been concerned with the purpose, content, methods, and results of mathematics at various levels. The second activity has been concerned with a reorganization of the whole school curriculum including among other considerations a careful evaluation of the effectiveness, in various subjects, of innovations in sequence, time allotments, grade placement, and requirements for graduation or college entrance.
Air Navigation
Authors: Pickett Hale
Published: January 2021

As a teacher of mathematics, I have been interested in the opposition to mathematics as a required subject in the high school and college.
The Picnic Problem
Authors: Jerbert A. R.
Published: January 2021

Teachers will readily recall the fundamental 4-step procedure which elementary algebra supplies for solving any and every kind of problem which presents itself.
Flying High
Authors: Moore Lillian
Published: January 2021

Why do we not capitalize on the absorbing interest of youth in flying? The armed forces want boys who have a thorough knowledge of the fundamentals of mathematics. Such a foundation can be given through a course in aerial navigation. First, it is assumed that boys who are interested in becoming aviation cadets and girls who wish to be future WASPS are intellectually superior pupils; hence they should have completed two years of mathematics, including elementary algebra and plane geometry, and either have completed or be studying simultaneously intermediate algebra. If possible, a term of plane and spherical trigonometry should be a prerequisite. With such a background pupils are eligible for an elementary course in aerial navigation, which will prove to be a magic carpet transporting both pupils and instructor to the enchanted realm of planes, flights and pilots.
A Study of Weights and Measures
Authors: Yorke Gertrude Cushing
Published: January 2021

For most mathematicians the metric system1 has a definite lure, because it is completely logical and mathematically perfect. Naturally it appeals strongly to them since it was the brainchild of some celebrated mathematicians who during the French Revolution were commissioned to create a new system of weights and measures worthy of the new order. Unfortunately these mathematicians knew little of and cared still less about the mundane world of trade and industry. They were “idéalogues” as Napoleon styled them, not practical businessmen. In the early eighteen hundreds the French failed to conquer the world, but their “intellectuals” never gave up their dream of world domination in one field, that of weights and measures, and so metric propaganda has worked on unremittingly.
The Art of Teaching: The Present Crisis in the Teaching of Mathematics
Authors: Christman Laura E.
Published: January 2021

Said the geometry teacher to the boy— “I can't understand why you don't see that. It's as plain as the nose on your face.”
Why Mechanical Manipulation?
Authors: Tobey William S.
Published: January 2021

Just how difficult it is to purge our thinking mechanism of early implanted misconceptions is brutally manifest in Mr. Richter's splendid and most timely article in the February issue of The Mathematics Teacher. He states that it has been found that those aspects of algebra which involve thinking are retained to a much greater degree than those involving mechanical manipulations. To Mr. Richter and to most of us, who studied our high school algebra before the days when an over indulgent public became possessed with the mistaken notion that somehow the schools could literally implant education into a neutral mind, there really are no mechanical manipulations in algebra. No mental growth occurs from a manipulation that is not in direct response to some reasoned decision. Lapses in adherence to this principle in the forms of rules, such as invert divisor, transpose, change signs, cancel, and the like, are the cancerous infestations which, during our recent prodigious experiment in the field of untrained and inadequately and inexpertly supervised teaching, have brought down upon us the present widespread and generally warranted criticism.
Measuring Arithmetical Achievement
Authors: Engen Lela G. Van
Published: January 2021

Some of the common questions that confront the classroom teacher in regard to arithmetic are closely related to measurement and based on what should be taught. A few of the questions might be stated: How can tests be improved so that fundamental concepts, reasoning and estimation can be measured? Do people who have ability in computation also have ability in reasoning and estimation? Would arithmetic have a better carry-over into real life if the reasoning type of arithmetic were stressed?
High School Mathematics After the War
Authors: Carnahan Walter H.
Published: January 2021

We are now engaged in a great global war which compels a searching evaluation of the educational principles that have been guiding us. If this evaluation were confined to the military results of the application of these principles, we could readily excuse any revealed shortcomings on the ground that we have been justifiably training for the pursuits of peace. But to the most casual observer, it is clear that the exposed defects are by no means wholly or even chiefly military. So far as the speaker is aware, not one of the many voluble critics of our educational products has complained because girls in overalls or boys in uniform have not been taught how to make bombs or to navigate bombers.
The Art of Teaching: School Situations Vitalize Mathematics
Authors: Palmer Bertha Weir
Published: January 2021

In our 9th grade course in General and Commercial Mathematics the pupils have had an opportunity to “learn to do by doing.” The experiences which have arisen from the venture have made the course both profitable and enjoyable. The Glen Rock Junior High School has an enrollment of almost 300 pupils, of whom some twenty take this course in their 9th year. Much of the success of our undertaking to integrate the course with the business life of the school is due to a sympathetic and understanding principal, cooperative and friendly secretaries and the very helpful teacher in charge of the school cafeteria.
Do I Have to Take Mathematics?
Authors: Marie Sister Noel
Published: January 2021

This too frequently repeated question puts mathematics in the same category as spinach. Why spinach? Because of the young American who used to wail (before the days of Pop-Eye), “Do I have to eat spinach?” I wonder if the answer for both questions is, “Yes, it is good for you.” Judging by the number of high school graduates who are making application to enter college and who have had a minimum of mathematics in secondary school, many principals and guidance directors do not think mathematics at all necessary for the intellectual life of their students.
Verbal Problems—Again!
Authors: Wible Josephine
Published: January 2021

This article is written to suggest to other teachers of high school algebra a possible way of compromising with those ever-present students in an algebra class who maintain that it is ridiculous to be obliged to solve a verbal problem by algebra when it can be solved more quickly and easily by arithmetic. To be sure, no one can say when or where arithmetic leaves off and algebra begins; but we well know what a pupil means when he insists on the arithmetic procedure.
Models for Certain Pyramids
Authors: Nyberg Joseph A.
Published: January 2021

The proof for the volume of a triangular pyramid involves showing that the pyramid is one of theee equal pyramids that form a prism. To make paper models of the three pyramids most pupils make the prism first and then measure certain lines in it to find the edges of the pyramids. But even when making the oblique prism the pupil has no direct geometric method for making the third lateral face after he has constructed two of the faces; that is, after making a pattern for ΔABC, for parallelogram ABDF, and for parallelogram BCED, he cannot construct parallelogram ACEF because he knows neither the diagonal CF, nor the angles at the vertices, nor any altitude of the parallelogram.
A Suggested Program for Teaching the Function Concepts in High School Algebra
Authors: Hendershot W. G.
Published: January 2021

We are all familiar with the complaint of teachers of other subjects, especially physics, that their pupils do not know mathematics, not even the simplest kind of manipulation involving nothing more than the most elementary forms of arithmetic and algebra. If such criticism is unjustified, we should defend ourselves and produce facts to support the competence of our instruction. Often we have been too complacent about this. We have been too content to go serenely along our way assuming a lofty, unconcerned air as if to say, “Are we not experts in the field of mathematics?” or “Isn't it a little presumptuous on the part of teachers in other fields to criticise us?”
Division of Decimal Fractions
Authors: Crofts Mary E.
Published: January 2021

The articles on division of decimal fractions in the February and May 1945 issues of The Mathematics Teacher invite this paper.
A Program of Diagnostic Testing and Remedial Treatment in Arithmetic
Authors: Fuller Joseph E.
Published: January 2021

It is common knowledge that a great many pupils find arithmetic to be difficult, and it is also generally known that the school population, as well as the general population, performs arithmetically on a level far below its normal expectancy. The results of tests by the Armed Forces involving arithmetic abilities merely tended to emphasize this fact.
The President's Page: New Year Resolutions
Authors: Mayor John R.
Published: January 2021

At the beginning of a new year many people feel an urge to make resolutions directed toward the improvement of their chosen life work. Such a practice seems a highly desirable one particularly if the urge is sufficiently strong to be accompanied by the determination to hold fast to the carrying out of the resolutions. By the time that members of the National Council read these paragraphs I hope that self-evaluation of 1952 has already suggested some worthy objectives for special new emphasis in 1953.
General Ways to Identity Students with Scientific and Mathematical Potential
Authors: Fehr Howard F.
Published: January 2021

The task of identifying giftedness is not an easy one. In December 1940, a two- day conference and workshop on education for the gifted was held at Teachers College in honor of the great work done by Leta Hollingworth. One section of outstanding teachers and educational research workers devoted itself entirely to the task of identifying the gifted child. The conclusion reached was: “At the present time we have practically no adequate instrument for identifying the gifted.”1 In The Gifted Child2 edited by Paul Witty, we read, “Present means of identifying and guiding the gifted leaves much to be desired,” and the rest of the brief chapter gives adequate support to this stand both in its meagerness of discussion and the problems for investigation that are raised. Even the latest book on Educating Gifted Children3 a report on the Hunter College Elementary School Program by Gertrude Hildreth and others, takes the same point of view regarding our ability to detect the gifted at an early age. Formal tests seem to be the one criteria that most people rely upon.
General Education Values of Mathematics and the Attempt of a Faculty to Teach Them
Authors: Abernethy John R.
Published: January 2021

Mathematics in general education rests upon these axioms. We believe: (1) that mathematics contains values that everyone needs; (2) that most people are capable of acquiring needed values from mathematics; and (3) that the worth of the individual justifies the effort required to give him or her these values.
Using Recreational Mathematics Materials in the Classroom
Authors: Brandes Louis Grant
Published: January 2021

The value of recreational mathematics has long been recognized by the mathematics teachers. The variety and inherent interest in recreational mathematics items can be utilized to improve pupil attitudes and to make learning more effective. Some teachers have found such items a useful device in overcoming emotional blocks to learning. The pupil who finds an interest in the recreational side of mathematics acquires a permanent source of enjoyment. The teacher who has materials available in this area has resources for making classwork more effective.
The Carpenter's Rule: An Aid in Teaching Geometry
Authors: Moore Ethel L.
Published: January 2021

The carpenter's rule is an excellent manipulative device to use in teaching meaningful informal and formal geometry. A carpenter's rule (folding or zig-zag) is a 72-inch or 84-inch measuring stick that folds at joints 0 inches apart.
On Asking Questions
Authors: Simpson T. M.
Published: January 2021

A teacher of college mathematics learns after some experience with freshmen that it is more important to ask a good question than to answer it. The writer has been experimenting with a class in analytic geometry, trying to direct their thinking into a clearer realization of the usefulness of self-put questions. Repeatedly an instructor will ask a question of the class and receive an answer unrelated to the question, or one which indicates that the nature of the problem did not register. Communication between the teacher and the class breaks down. He asks for an equation and gets a formula. He inquires about factors and gets roots. Seeking the area of a triangle, he obtains a guess at the vertices. Examples can be multiplied ad infinitum.
Application
Authors: Ranucci Ernest R.
Published: January 2021

In the past I have found that the seventeenth yearbook of the National Council of Teachers of Mathematics, A Source Book of Mathematical Applications, has been a wonderfully helpful volume in keeping mathematics students interested. I am adding several examples of the geometry connected with carpentry to the many found in the seventeenth yearbook.
Analysis: notes on the evolution of a subject and a name
Authors: Boyer Carl B.
Published: January 2021

traces briefly the historical rise of one of the three main divisions of mathematics, with particular reference to changes in the use of the term “analysis.”
What is Going On in Your School?: Shall they take geometry?
Authors: Ling Carmel
Published: January 2021

One hundred twenty-five letters were mailed to parents—and just two weeks before the end of the school year. Would you do this? We did, in the effort to create parent interest as well as to help counsel our students about taking geometry. This was only the last step in a long counseling program and the results we obtained paid for the effort involved.
Quod erat demonstrandum
Authors: Fawcett Harold P.
Published: January 2021

The essence of mathematics is not in the form of a proof as it appears on paper, and the intellectual glow which its study engenders arises through an insight into mathematical patterns and processes.
What is Going On in Your School? The influence of the study of plane geometry on critical thinking
Authors: Massimiano Carmen C.
Published: January 2021

In studies that have surveyed the purposes of teaching geometry, such reasons as, “to teach the students to think logically,” and, “to understand the meaning of deductive proof,” were most frequently mentioned. In one important survey that tabulated the opinions of 500 classroom teachers concerning the important objectives of teaching geometry, the one receiving the highest rating was, “to develop the habit of clear thinking and precise expression.”
Points and Viewpoints: What's new in mathematics?
Authors: Wren F. Lynwood
Published: January 2021

A column of unofficial comment
Still more on the cutting of squares
Authors: _ _
Published: January 2021

Discussions of this subject in The Mathematics Teacher for May 1956 and October 1956 are here brought to culmination in a constructive proof of the theorem that any convex polygon is equivalent to a square. The present paper also provides material that supplements material in the same vein in The Mathematics Student Journal for December 1956.
What Mathematical Subjects Should be Included in the Curriculum of the Secondary Schools
Authors: McKeehan Charles L.
Published: January 2021

The President of your Association has asked me to discuss this subject from the point of view of the professions. Surely a daring undertaking for one who knows nothing about mathematics except the simplest operations in integers and fractions, who knows as an abstract proposition that two and two make four, but who frequently finds that they make three or five to him when he adds them in a column of figures, and (to come closer to the point) who never did really understand the principles of mathematics, although he graduated from a famous preparatory school and escaped from the university of Pennsylvania with a bachelor’s degree.
Alexa, Are You Listening?
Authors: Sweeney Miriam , Davis Emma
Published: January 2021

Smart voice assistants have expanded from personal use in the home to applications in public services and educational spaces. The library and information science (LIS) trade literature suggests that libraries are part of this trend, however there are few empirical studies that explore how libraries are implementing smart voice assistants in their services, and how these libraries are mitigating the potential patron data privacy issues posed by these technologies. This study fills this gap by reporting on the results of a national survey that documents how libraries are integrating voice assistant technologies (e.g., Amazon Echo, Google Home) into their services, programming, and checkout programs. The survey also surfaces some of the key privacy concerns of library workers in regard to implementing voice assistants in library services. We find that although voice assistant use might not be mainstreamed in library services in high numbers (yet), libraries are clearly experimenting with (and having internal conversations with their staff about) using these technologies. The responses to our survey indicate that library workers have many savvy privacy concerns about the use of voice assistants in library services that are critical to address in advance of library institutions riding the wave of emerging technology adoption. This research has important implications for developing library practices, policies, and education opportunities that place patron privacy as a central part of digital literacy in an information landscape characterized by ubiquitous smart surveillant technologies.
noción de daño y su rol en los juicios morales. Un debate abierto
Authors: Silva Carrero Gustavo Adolfo , Reyes Higuera Gustavo Alejandro , Peña Camargo Gustavo Adolfo , Rosas López Alejandro
Published: January 2021

Investigadores pertenecientes a la tradición de la psicología del desarrollo cognitivo han llevado a cabo estudios que sugieren que existe un vínculo entre la percepción de daño y el dominio moral. Frente a esta propuesta unificadora del dominio moral han surgido críticas desde la psicología cultural. Haidt publicó en 1993 uno de los estudios más influyentes en esta línea, afirmando haber encontrado evidencia que sugiere la existencia de dominios morales no vinculados a la noción de daño. En este artículo se hará una presentación general del debate en torno al contenido del dominio moral. Luego presentaremos y evaluaremos el estudio de Haidt et al. (1993). Por último, presentamos resultados experimentales que cuestionan las conclusiones de ese estudio y sugieren que el debate sigue abierto.

Researchers belonging to the tradition of cognitive-developmental psychology have suggested studies that the perception of harm is central to the Moral Domain. This unifying proposal of the Moral Domain has provoked the criticisms of researchers working in Cultural Psychology. Haidt published in 1993 a very influential study, claiming to have found evidence for the existence of Moral Domains not linked to the notion of harm. In this paper, we briefly present the debate around the content of the moral domain. We then critically examine the study by Haidt et al. (1993). Finally, we present experimental results that question the conclusions of their study and suggest that the debate is still open.
Datación de la lengua del lybro de Magyka (MS. 5-2-32, Biblioteca Colombina, Sevilla)
Authors: Aléxia Duchowny , Luíza Pereira
Published: January 2021

El objetivo de este trabajo es identificar la fecha aproximada de la producción del texto del manuscrito Lybro de magyka, la tercera parte de una obra sobre astrología, en espanõl, comprada por Hernando Colón en 1527, que se conserva hoy en la Biblioteca Colombina, Sevilla, bajo la inscripción Ms. 5-2-32. Nuestra hipótesis es que el texto fue escrito entre los siglos XIII y XVI. Por lo tanto, la base teórica está constituida por gramáticas históricas de la lengua española que traen las siguientes características representativas del español medieval que nos permitieran elaborar criterios para el análisis que comprobarían o no la hipótesis inicial: 1) la formación de adverbios con el sufijo -mientre; 2) los masculinos hechos en -a que adoptan concordancia femenina; 3) la aspiración de la f- inicial; 4) el cambio de la copulativa et para y; 4) el adverbio suso. Los resultados permiten observar que la lengua del manuscrito fecha probablemente de finales del siglo XIV o del siglo XV, lo que se encuentra de acuerdo con las hipótesis de autoría propuestas por los trabajos acerca del Lybro de magyka hasta el momento. Así, el presente estudio contribuye para la reconstrucción de la historia del códice y para los estudios acerca de la lengua española.

The objective of this work is to identify the approximate date of the production of the text of the manuscript Lybro de magyka, the third part of a work on astrology, in Spanish, purchased by Hernando Colón in 1527, which is preserved today in the Biblioteca Colombina, Seville, Spain, under the registration Ms. 5-2-32. Our hypothesis is that the text was written between the thirteenth and sixteenth centuries, and is a copy of a Catalan translation. Therefore, the theoretical basis is constituted by works of internal and external history of the Spanish language that bring representative characteristics of the medieval Spanish. The characteristics below allow to elaborate criteria for the analysis that would verify or not the initial hypothesis: 1) the formation of adverbs with the suffix -mientre ; 2) the masculine ones made in -a that adopt feminine concordance; 3) the change of the copulative et to y; The results show that the language of the manuscript probably dates from the fifteenth century, which is in accordance with the hypotheses of authorship proposed by the works on the Lybro de Magyka so far. Thus, the present study contributes to the reconstruction of the history of the codex and to the studies about the Spanish language.
Kanarya Otu (Senecıo Vernalıs) Bitkisinin Doğal Boyamacılıkta Kullanılabilirliğinin Araştırılması
Authors: ALA Deniz Mutlu , BAKICI Gamze Gülşen
Published: January 2021

Plants, which are the biggest source of natural dyes, have been used as coloring agents since the beginning of humanity. In this study, the usability of eastern groundsel, which is thought to be an alternative for the textile dyeing industry, especially for sustainable and renewable textile production, was investigated. Dyeing processes were performed with different concentrations of dyeing baths of natural dye which is extracted from the crowns of the eastern groundsel (Senecio vernalis) plant. After dyeing, dye flotte concentrations were determined using UV-visible spectrophotometer and the percent uptake of natural dye on cotton fabric was measured Spectrophotometric color analysis of the fabrics was performed and fastnesses of the samples were evaluated. It was found that the coloration of cotton fabrics with the use of Eastern groundsel (Senecio vernalis) in suitable dyeing application conditions could be managed with almost sufficient fastnesses.
Bacterial symbiont subpopulations have different roles in a deep-sea symbiosis
Authors: Hinzke Tjorven , Kleiner Manuel , Meister Mareike , Schlüter Rabea , Hentschker Christian , Pané-Farré Jan , Hildebrandt Petra , Felbeck Horst , Sievert Stefan M , Bonn Florian , Völker Uwe , Becher Dörte , Schweder Thomas , Markert Stephanie
Published: January 2021

The hydrothermal vent tubewormRiftia pachyptilahosts a single 16S rRNA phylotype of intracellular sulfur-oxidizing symbionts, which vary considerably in cell morphology and exhibit a remarkable degree of physiological diversity and redundancy, even in the same host. To elucidate whether multiple metabolic routes are employed in the same cells or rather in distinct symbiont subpopulations, we enriched symbionts according to cell size by density gradient centrifugation. Metaproteomic analysis, microscopy, and flow cytometry strongly suggest thatRiftiasymbiont cells of different sizes represent metabolically dissimilar stages of a physiological differentiation process: While small symbionts actively divide and may establish cellular symbiont-host interaction, large symbionts apparently do not divide, but still replicate DNA, leading to DNA endoreduplication. Moreover, in large symbionts, carbon fixation and biomass production seem to be metabolic priorities. We propose that this division of labor between smaller and larger symbionts benefits the productivity of the symbiosis as a whole.
Longitudinal high-throughput TCR repertoire profiling reveals the dynamics of T-cell memory formation after mild COVID-19 infection
Authors: Minervina Anastasia A , Komech Ekaterina A , Titov Aleksei , Bensouda Koraichi Meriem , Rosati Elisa , Mamedov Ilgar Z , Franke Andre , Efimov Grigory A , Chudakov Dmitriy M , Mora Thierry , Walczak Aleksandra M , Lebedev Yuri B , Pogorelyy Mikhail V
Published: January 2021

COVID-19 is a global pandemic caused by the SARS-CoV-2 coronavirus. T cells play a key role in the adaptive antiviral immune response by killing infected cells and facilitating the selection of virus-specific antibodies. However, neither the dynamics and cross-reactivity of the SARS-CoV-2-specific T-cell response nor the diversity of resulting immune memory is well understood. In this study, we use longitudinal high-throughput T-cell receptor (TCR) sequencing to track changes in the T-cell repertoire following two mild cases of COVID-19. In both donors, we identified CD4+ and CD8+ T-cell clones with transient clonal expansion after infection. We describe characteristic motifs in TCR sequences of COVID-19-reactive clones and show preferential occurrence of these motifs in publicly available large dataset of repertoires from COVID-19 patients. We show that in both donors, the majority of infection-reactive clonotypes acquire memory phenotypes. Certain T-cell clones were detected in the memory fraction at the pre-infection time point, suggesting participation of pre-existing cross-reactive memory T cells in the immune response to SARS-CoV-2.
In situ dissecting the evolution of gene duplication with different histone modification patterns based on high-throughput data analysis in Arabidopsis thaliana
Authors: Wang Jingjing , Orlov Yuriy L. , Li Xue , Zhou Yincong , Liu Yongjing , Yuan Chunhui , Chen Ming
Published: January 2021

Background

Genetic regulation is known to contribute to the divergent expression of duplicate genes; however, little is known about how epigenetic modifications regulate the expression of duplicate genes in plants.

Methods

The histone modification (HM) profile patterns of different modes of gene duplication, including the whole genome duplication, proximal duplication, tandem duplication and transposed duplication were characterized based on ChIP-chip or ChIP-seq datasets. In this study, 10 distinct HM marks including H2Bub, H3K4me1, H3K4me2, H3K4me3, H3K9ac, H3K9me2, H3K27me1, H3K27me3, H3K36me3 and H3K14ac were analyzed. Moreover, the features of gene duplication with different HM patterns were characterized based on 88 RNA-seq datasets of Arabidopsis thaliana.

Results

This study showed that duplicate genes in Arabidopsis have a more similar HM pattern than single-copy genes in both their promoters and protein-coding regions. The evolution of HM marks is found to be coupled with coding sequence divergence and expression divergence after gene duplication. We found that functionally selective constraints may impose on epigenetic evolution after gene duplication. Furthermore, duplicate genes with distinct functions have more divergence in histone modification compared with the ones with the same function, while higher expression divergence is found with mutations of chromatin modifiers. This study shows the role of epigenetic marks in regulating gene expression and functional divergence after gene duplication in plants based on sequencing data.
Invasive mangroves produce unsuitable habitat for endemic goby and burrowing shrimp pairs in Kāneʻohe Bay, O‘ahu, Hawai‘i
Authors: Hansen Mandy , Crow Karen D , Buchbinder Margot V , Boyer Katharyn E
Published: January 2021

Hawai‘ian ecosystems evolved in relative isolation and support an abundance of native and endemic species. As such, they are particularly vulnerable to introduced species that alter habitat and interfere with species interactions. Although mangroves are valued globally for shoreline protection and other services, their invasion of the Hawai‘ian islands may have negative effects on the abundance and functions of native species. On an island in Kāne‘ohe Bay, O‘ahu, we explored the relationship between invasion of the red mangrove, Rhizophora mangle, and abundance of the native burrowing shrimp Alpheus rapax, which shares its burrows with the endemic goby Psilogobius mainlandi in a mutualism that reduces predation on both. We hypothesized that the abundance of shrimp/goby burrows is reduced beneath mangroves due to increased cover associated with mangrove prop roots, which trap leaves and debris and may harbor the invasive red alga Gracilaria salicornia. At 3 mangrove-invaded sites, we conducted a survey of burrow density and benthic debris and found ~4–5× lower burrow density and 4× greater cover of debris under the mangrove edge compared to sandflats that were 1.5 and 5.0 m away. Burrow density was negatively correlated with total cover of benthic debris and with subgroups of that cover composed of G. salicornia or leaves. We tested the effect of debris removal over 2 weeks, which resulted in 3–8× more burrows. Thus, we provide evidence that invasive red mangroves, through trapping leaves and promoting presence of invasive G. salicornia among their prop roots, have strong negative effects on shrimp/goby burrow density. Although our study was limited in spatial scope, we propose that current efforts to remove mangroves in Hawai‘i, for both cultural and ecological reasons, will mitigate negative effects on endemic goby and native shrimp habitat.
Optimal Mix Design and Quality Properties of 50 MPa Self-Consolidating Lightweight Concrete
Authors: Hong Se-Hee , Choi Jin-Seok , Lee Jaehoon , Yoon Young-Soo
Published: January 2021

In this study, basic data were used to quantitatively determine the initial properties of self-consolidating lightweight concrete by analyzing various characteristics, such as air content, workability, segregation resistance, filling capacity, air/dry density, and strength according to the incorporating ratio of lightweight aggregate. With the exception of Mixture (LF75-LC100) that uses 100% lightweight coarse aggregate (LC) and 75% lightweight fine aggregate (LF), all the mixtures satisfied the performance criteria for workability, segregation resistance, and filling capacity, as suggested in the JSCE, and air/dry density, as suggested in the Concrete Standard Specification. The compressive strength of all the variables, except the LF75-LC100, was measured to be at least 50 MPa, but the strength decreased in a manner similar to that depicted in previous research when LC was incorporated. The results of the above experiments indicated that 100% of the LC and 50% of the LF was the optimal mix for self-consolidating lightweight concrete.
Experimental Evaluation of Internal Blast Resistance of Reinforced Concrete Structures using Blast Resistance Panels
Authors: Sim Bohoon , Kim Kukjoo , Kim Chunho , Park Sang-woo , Baek Jang-woon , Park Youngjun
Published: January 2021

Blast loading varies based on the location of the explosion. Furthermore, blast loading can be classified into unconfined explosions and confined explosions. Many studies have evaluated blast resistance performance based on unconfined explosions, focusing on military applications. However, there is a paucity of studies considering confined explosions. Given that confined explosions are significantly different from unconfined explosions, full-scale field experiments are necessary for the development of numerical models. Therefore, in this study, the performance of blast resistance panels was evaluated as a method for reducing explosion pressure in facilities such as underground ammunition storage. Two structures were manufactured using normal-strength and high-strength concrete, and 5.9 kg of TNT was blasted internally. The experimental results confirmed that the maximum acceleration could be reduced by 28.87% and 61.65% in the normal-strength and high-strength concrete structures, respectively, when using a blast resistance panel.
Evaluation of Slope Stability of Reservoir Considering Heterogeneous Soil Properties
Authors: Shin Seungwon , Lee Sangbeen , Lee Sungsu , Jung Jongwon
Published: January 2021

The slope stability evaluation of reservoirs is required because of the aging of reservoirs. Reservoir levees are designed to achieve homogeneous construction, but the spatial heterogeneity of the material properties of reservoirs is unavoidable. Because the existing method for evaluating reservoir stability is limited in terms of considering the spatial heterogeneity of material properties, the stability evaluation was conducted in this study, in which the spatial heterogeneity and uncertainty of the material properties of the reservoir levee were considered. In addition, the results for the existing and proposed methods were compared and analyzed, and the variability of the entire material properties of the reservoir levee, instead of spatial heterogeneity, was reflected. The evaluation results confirmed that the probability of failure obtained using the proposed method was lower than that for the existing stability evaluation method, considering the variations in material properties because the levee did not reach the critical state, owing to changes in local properties. Therefore, the proposed method is useful for the cost-effect repair and reinforcement of reservoir slopes, compared to the existing slope stability evaluation method.
Detection of Cavities Beneath Plate Structure using a Microphone
Authors: Kang Seonghun , Lee Jong-Sub , Yu Jung-Doung , Kim Sang Yeob
Published: January 2021

Failure of plate structures such as pavements can be caused by the occurrence of cavities beneath the structure. In this study, a cavity beneath the plate structure were detected in a laboratory model chamber using a hammer and microphone. Specifically, a chamber was constructed using an acrylic plate and dry soil to simulate the pavement and the subgrade, respectively. A plastic box was placed between the acrylic plate and dry soil to simulate a cavity beneath the pavement. The sound waves generated by impacting the acrylic plate with a hammer were measured using a microphone. The measured area under the rectified signal envelope (MARSE) energy was calculated for the measured sound waves, and the variation in it were analyzed according to the measurement location. The test results show that the signal attenuation was low at the cavity section owing to the conservation of impact energy and that the signal amplitude becomes lower at the soil section owing to the weakened flexural vibration. Therefore, the estimated MARSE energy at the cavity section was larger than that at the soil section. This study demonstrates the effective utilization of microphones for detecting cavities beneath the plate structures.
Study on Installation Standards of Reduction Facilities considering Flow Condition of Small Drainage
Authors: Song Youngseok , Joo Jingul , Kim Hayong , Jeong Sangman , Park Moojong
Published: January 2021

While drainage installed in mountainous and urban areas play various roles for supplying and draining water, the standards for reduction facilities and maintenance are insufficient. In the case of small drainage, if there is an inflow of deposited debris, overflow damage occurs due to lack of water supply capacity. In this study, a reduction facility was developed to block the transport of debris in a small drainage. The equation considering installation standards was proposed by analyzing capture efficiency through hydraulic experiment. By establishing various experimental conditions, a total of 900 experiments were conducted using 90 different conditions. The reduction effect of reduction facilities was analyzed by consideration of flow conditions such as discharge and Froude Number. Multiple regression analysis was conducted to develop an equation that considers the installation standard of a small drainage. The dependent variable was capture efficiency, and the independent variables were discharge, Froude Number, and an effective cross sectional area of reduction facilities. The equation considering installation standard of small drainage is E = 1.337-5.074×Q-0.156Fr-132.710A and the significance is high. The results of this study are expected to be applied to reduction facilities suitable for target capture efficiency targeting small drainage.