bluuebunny/crossref_metadata_2025 huggingface dataset:
Interactions between Structure-of-Intellect Factors and Two Methods of Presenting Concepts of Modulus Seven Arithmetic: A Follow-up and Refinement Study
Authors: Behr Merlyn J. , Eastman Phillip M.
Published: August 2020

The purpose of this study was to replicate and generalize the findings of two earlier ATI studies. 205 Ss were pretested for cognitive ability and then were randomly assigned to 1 of 2 treatments (figural vs. verbal) on a unit in modulus seven arithmetic. Subjects were given 1 class period to study the programmed material and 1 week later retention and transfer tests were administered. The results did not support the earlier findings in this area and indicate that perhaps more investigation in the area of aptitude test construction might be justified. Although not limited to the ATI area, the results indicate that more replication studies are needed before we begin to weigh first results too heavily.
Elementary and Middle School Children's Comprehension of Euclidean Transformations
Authors: Kidder F. Richard
Published: August 2020

A recurring question of interest to curriculum writers and mathematics educators is the following: “What geometry should be taught in the elementary and middle schools, at what age, and in what context?” Substantive recommendations for the inclusion of transformational geometry in the elementary and middle school curriculum have been made and are being implemented. However, there is a scarcity of research data on which to base these innovations. More specifically, little empirical evidence exists concerning the spatial capability of children with respect to Euclidean transformations. Hence, the present study was devised to investigate 9, 11, and 13 year-old children's comprehension of Euclidean transformations; that is, to investigate their ability to form a mental image of a planar figure, to perform a mental operation (a Euclidean transformation) on this representation, and then to construct the resultant in correct position.
The Influence of an Advanced Organizer on Two Types of Instructional Units about Finite Geometries
Authors: Lesh Richard A.
Published: August 2020

This study involved 48 Northwestern University students who were enrolled in C26-1 Geometry. The theoretical point of view underlying the study predicted that advanced organizers should be most effective in situations where structural integration is a problem, and that the “learning hierarchy” model for constructing instructional materials can accentuate problems that arise because of structural integration.
The Relative Effectiveness of Four Strategies for Teaching Algebraic and Geometric Disjunctive Concepts and for Teaching Inclusive and Exclusive Disjunctive Concepts
Authors: Dossey John A.
Published: August 2020

The purpose of this study was to determine the role played by four instructional strategies and two exemplification-move approaches in teaching algebraic and geometric concepts as well as in teaching inclusive and exclusive disjunctive concepts to students of two different intellectual-ability levels. Eight programed instructional units were prepared to teach 12 contrived disjunctive concepts to 320 subjects. An analysis of the results showed that there were significant differences in the strategy factor for algebraic and inclusive-disjunctive concepts. There was a significant difference in the exemplification-approach factor for inclusive-disjunctive concepts. Significant three-way interactions were observed for geometric and exclusive disjunctive concepts.
A Comparison of Two Methods of Column Addition
Authors: Wheatley Grayson H.
Published: August 2020

Speed and accuracy in adding a column of one-digit numbers directly down a column was compared to adding by looking for combinations that add up to ten. Ninety-two fourth-grade subjects learned one of these two methods over a one-week period and then learned the other method the following week. Using timed tests after each treatment, it was found that the direct method was much faster (p < .001) and just as accurate as the tens method. This held for all ability levels. There was a slight preference for the tens method after training. The results suggest that a computational procedure that requires less decision making is more efficient.
Research on Mathematics Education Reported in 1975
Authors: Suydam Marilyn N. , Weaver J. F.
Published: August 2020

This is the sixth annual listing of research on mathematics education to be published in JRME. As in previous listings, the research is organized alphabetically by author(s) within each of three categories—research summaries, journal-published reports, and dissertation abstracts. The subset of Piagetian-oriented research is listed separately in each of the latter two divisions.
The Effects of Three Instructional Strategies on Problem-Solving Behaviors in Secondary School Mathematics
Authors: Vos Kenneth E.
Published: August 2020

There are a number of behaviors or heuristics that can be identified as important or useful for solving mathematical problems. The study compared three instructional strategies for promoting the selected behaviors of drawing a diagram, approximating and verifying, constructing an algebraic equation, classifying data, and constructing a chart. The experimental setting was six mathematics classes (N=133) across three grade levels (9, 10, 11) at a private high school in Iowa. The research design was a one-factor, randomized complete block with mathematics classes as a blocking variable. Each of the instructional strategies involved working on a problem, but with variations in the placement of, and emphasis on, an implied problem-solving behavior. One instructional strategy involved only exposure to problems while the other two involved an instructional phase. The results indicated that the subjects given instruction on specific behaviors were more likely to exhibit and make effective use of the problem-solving behaviors in new problem situations.
The Introduction of Mathematics Through Measurement or Through Set Theory: A Comparison
Authors: Wagenen R. Keith Van , Flora June A. , Walker Alice A.
Published: August 2020

Traditionally, children are introduced to numbers by counting arrays of objects and identifying numbers with the objects as they count. In this study, measurement of linear distance was used as a concrete basis for teaching first-grade children the relation of unit to quantity and to give emphasis to the ordinal and transitive nature of natural numbers. Paper-and-pencil arithmetic and set theory were strictly avoided, but addition and subtraction of line segments and symbolic representation of the measurements were taught. Achievement criterion was in terms of two scores: (a) measurement concepts and quantities and (b) a test of “standard” textbook competence in set theory and counting operations. The children learning through measurement performed much better on the measurement evaluations and performed almost as well as comparison children on set theory evaluations.
The Effect of Computer Utilization on the Achievement and Attitudes of Ninth-Grade Mathematics Students
Authors: Robitaille David F. , Sherrill James M. , Kaufman David M.
Published: August 2020

Evaluations of the computer-augmented mathematics programs in two secondary schools were conducted over a 4-month (School A) and a 9-month (School B) period with respect to mathematics achievement and attitudes. Analysis of the achievement data in School A revealed significant (p<.01) variation among the groups with the computer group lower than the other two groups. In School B significant (p<.01) variation on achievement found the no-computer group higher than the other two groups, but there may have been a confounding teacher effect. Analysis of the attitude data from School A revealed significant variation among the three groups with the computer group having the most positive attitude. No significant variation in attitude was found among the three groups in School B.
Critique: Response to Kulm's Critique
Authors: Bassler Otto C. , Beers Morris I. , Richardson Lloyd I.
Published: August 2020

It is evident that there is a lack of agreement about heuristics or the heuristic method. Kulm deplores the lack of a clear or consistent meaning of heuristic but does not attempt a definition or working description. This lack of definition appears to limit the validity of his criticisms of the two articles. It was also precisely this lack of definition that led us to describe clearly the strategies for solving word problems that were used in our study. In this way we provided an operational definition for those who wish to construe this study as a heuri stic one. It is debatable, however, if all problem–solving research should be characterized as the teaching of heuristics.
A Forum for Researchers: Reactions to the Third International Congress on Mathematical Education
Authors: Wheeler David
Published: August 2020

The 3rd International Congress on Mathematical Education attracted over 2,500 people to Karlsruhe, West Germany—substantially more than attended the First, at Lyons, France, in 1969, or the Second, in Exeter, England, in 1972. (The second Congress provided the substance of the book Developments in Mathematical Education, edited by A. G. Howson, Cambridge University Press, 1973.)
Letters to the Editor
Authors: Scott Douglas E. , Aiken Lewis R.
Published: August 2020

In the early days of standardized testing. eager practitioners sought to find a single score that would completely classify a student. David Rappaport suggests [in his letter in March 1977 JRME] that we are heading for the same trap in our statistical comparisons of various methods, trying to find “the best way” to teach algebra, or multiplication, or whatever.
A Forum for Researchers: Recent Cooperative Research concerning the Acquisition of Spatial and Geometric Concepts
Authors: Lesh Richard
Published: August 2020

In the spring of 1975, the Georgia Center for the Study of Learning and Teaching in Mathematics (GCSLTM) sponsored a series of five research workshops involving (a) teaching strategies in mathematics, (b) number and measurement concepts, (c) space and geometry concepts, (d) models for learning mathematical concepts, and (e) problem solving. This fo rum is a discussion of the activities of the working group that developed from the space and geometry workshop. The existence of a successful, nonfunded, multi-institutional, cooperative research effort is in itself a significant research innovation in mathematics education.
Teachers', Principals', and University Faculties' Views of Mathematics Learning and Instruction as Measured by a Mathematics Inventory
Authors: Post Thomas R. , Ward William H. , Willson Victor L.
Published: August 2020

Differences and similarities among the views of secondary mathematics teachers (n=199), high school principals (n=160), and college mathematics education professors (n=117), as reflected by responses on an inventory concerned with cognitive and affective aspects of mathematics learning and instruction, were examined. The response patterns of each group analyzed by factor analysis or analysis of variance methods were found to have some unique characteristics: however, teachers were found to be more similar to principals than to college professors in both factor structure and individual item responses. Implications of this finding for the transmission of innovation in instruction are discussed.
Brief Reports: Interaction between Structure of Intellect Factors and Two Methods of Presenting Concepts of Logic
Authors: Eastman Phillip M. , Behr Merlyn J.
Published: August 2020

The study reported is directly related to the work of Eastman (1975), which was a continuation of work begun by Carry (1968) and Webb (1971). Eastman obtained a significant interaction when the criterion measure of transfer was regressed on factors of general reasoning and spatial visualization. The Necessary Arithmetic Operations test and the Abstract Reasoning test of the Differential Aptitude Test Battery were used to measure these aptit udes, respectively. Two treatments, one graphical and the other analytical, were used to present methods for finding solution sets of quadratic inequalities. In the graphical treatment, concepts were presented in a symbolic-deductive mode. Eastman observed that factor analytic studies indicated that the measure for spatial visualization used by Carry and Webb (paper folding) had factor loadings on deduction. Conjecturing that the problem of deductive versus inductive presentation of the learning material might have been a confounding variable in the studies by Carry and by Webb, Eastman selected a different measure for spatial visualization, revised the instructional treatments to reflect a figural-inductive mode and a symbolic-deductive mode of presentation, and was successful in isolating an interaction.
A Forum for Researchers: A Note on the Power of Statistical Tests
Authors: Clark Robert C.
Published: August 2020

In the classical decision-making model, the experimenter seeks to demonstrate a difference between the distributions of two or more samples (or a sample and a population) for some parameter. A null hypothesis is stated that there is no “significant” difference between the distributions, and probabilistic models are used to determine the probability that any difference is due to chance. Philosophically, the researcher decides in advance that he is only willing to accept a probability less than a given size for making the error of assuming that the difference is real when it is actually due to chance. The a priori probability of such an error (Type I) is designated α. But the possibility of another error exists: the error of failing to reject a null hypothesis when the difference is real. (The a priori probability of such an error is designated β.) Whereas the probability of a Type I error has been controlled by the choice of a significance criterion, the Type II error (failing to reject a false null hypothesis) has seldom been controlled. However, the use of the technique of power analysis now makes it possible to control the probability of a Type II error with little more difficulty than the technique used to control the probability of a Type I error.
Hemispheric Specialization and Cognitive Development: Implications for Mathematics Education
Authors: Wheatley Grayson H. , Mitchell Robert , Frankland Robert L. , Kraft Rosemarie
Published: August 2020

Evidence is presented for hemisphere specialization of the two brain hemispheres: the left hemisphere specialized for logico-analytic tasks and the right hemisphere, visuo-spatial tasks. A hypothesis is put forth for the emergence of the specialization that suggests a shift from predominant right hemisphere processing in infancy to predominant left hemisphere processing in adulthood. Results of the studies reviewed suggest the emergence of concrete-operational thought as the left hemisphere becomes capable of processing logical tasks. Electroencephalography seems particularly useful in determining specialization and mapping changes in hemispheric asymmetry. Implications for school mathematics curriculum are presented.
A Forum for Researchers: Criteria for Judging Research Reports and Proposals
Authors: Coburn Terrence G.
Published: August 2020

One of the original charges to the NCTM's Research Advisory Committee (RAC) was the development of a set of criteria for evaluating research proposals and reports. This matter was taken up at an RAC meeting in September 1975, and a subcommittee (Stuart Choate and Terry Coburn) was given the task of reviewing and coalescing several available sets of criteria (Anderson & Kerr, 1968; Romberg, 1969; Steffe, 1975; Suydam, 1972). The subcommittee report was discussed at the January 1976 RAC meeting, and a subsequent version was announced in the September 1976 NCTM “Bulletin for Leaders.” Single copies of the report, “Criteria for Judging Research Reports and Proposals,” were made available in August 1976, free on request from the NCTM Headquarters Office. Two changes have since been made on the August report: (I) The incorporation of a “protection for human subjects” criterion and (2) the deletion of the last portion of the report—“Some Reasons for Rejection.”
The Use of Manipulative Materials and Student Performance in the Enactive and Iconic Modes
Authors: Barnett Jeffrey C. , Eastman Phillip M.
Published: August 2020

The purpose of this study was to test the prevailing assumption that preservice elementary teachers need concrete experience with manipulative aids to demonstrate numerical and structural properties of the four basic arithmetic operations. Thirty-nine students in the experimental group used manipulative aids to work laboratory exercises, whereas 39 students in the control group completed the same exercises without the use of these materials. No significant differences were found on a laboratory test requiring responses in a representational mode or on a test requiring the manipulation of the objects. Significant differences were found favoring the “hands on” group on a mathematics-concepts test.
Sex-Related Differences in Mathematics Achievement and Related Factors: A Further Study
Authors: Fennema Elizabeth H. , Sherman Julia A.
Published: August 2020

Relationships were investigated between mathematics learning, verbal ability, spatial visualization, and eight affective variables. Subjects were 1320 sixth through eighth graders. No sex-related differences over all schools were found for any cognitive variable. Females were significantly less confident of themselves in mathematics, and males stereotyped mathematics as a male domain higher than did females. Results were synthesized with those obtained at the high school level. Significant sex-related differences found in high school areas were not found in the same middle school areas. Where significant differences in achievement were found at both levels, they were accompanied by significant differences in many affective variables.
Brief Reports: Teacher Vagueness and Pupil Participation in Mathematics Learning
Authors: Smith Lyle R. , Edmonds Ed M.
Published: August 2020

Numerous studies have investigated the relationships between teacher behavior and student achievement. Many of the studies, however, have been descriptive rather than experimental in nature. For example, Hiller, Fisher, and Kaess (1969) and Smith (1977) found negative correlations between the frequency of teacher vagueness terms and student achievement. Shuster and Pigge (1965), Scandura and Behr (1966), Zahn (1966), an d Robitaille (1975) reported that mathematics teachers were more effective when they allowed their students to participate actively in developmental activities rather than to engage solely in a passive intake of information.
Brief Reports: Textbook Pictures and First-Grade Children's Perception of Mathematical Relationships
Authors: Campbell Patricia F.
Published: August 2020

An examination of current primary mathematics textbooks reveals that one method of communicating mathematical concepts to children is with dynamic pictures used in conjunction with written numeral statements. These pictures portray motion and are meant to serve as a reference either to assist the students in solving a related problem or to define a context within which the problem may be interpreted. However, it is necessary for the children to relate or assimilate the characters depicted in these pictures and to perceive the action portrayed before they can associate these pictures with the addition or subtraction of whole numbers.
Reviews
Authors: McLeod Douglas B.
Published: August 2020

The news media have reported the results of a study by the National Association of Secondary School Principals' Department of Research of “34 high schools around the country that have successfully resisted the trend toward falling [Scholastic Aptitude Test] scores” (New York Times. 28 March 1978). The news stories stressed the study's major conclusion that schools whose SAT scores have been stable or rising have emphasized academic coursework, but the stories gave as much or more weight to the suggestion that schools whose scores declined were too responsive to educational fads. Although the study specifically noted that one could not stereotype the schools according to innovative or traditional instructional methods, reporters and editorial writers read the study as condemning such innovations as the open classroom concept. The headline of the news story in the Atlanta Constitution on 2 April 1978 was typical: “Schools Avoid Fads, Students Do Better.”
How Artifacts Afford
Authors: Davis Jenny L.
Published: August 2020

A conceptual update of affordance theory that introduces the mechanisms and conditions framework, providing a vocabulary and critical perspective.

Technological affordances mediate between the features of a technology and the outcomes of engagement with that technology. The concept of affordances, which migrated from psychology to design with Donald Norman's influential 1988 book, The Design of Everyday Things, offers a useful analytical tool in technology studies—but, Jenny Davis argues in How Artifacts Afford, it is in need of a conceptual update. Davis provides just such an update, introducing the mechanisms and conditions framework, which offers both a vocabulary and necessary critical perspective for affordance analyses.

The mechanisms and conditions framework shifts the question from what objects afford to how objects afford, for whom, and under what circumstances. Davis shows that through this framework, analyses can account for the power and politics of technological artifacts. She situates the framework within a critical approach that views technology as materialized action. She explains how request, demand, encourage, discourage, refuse, and allow are mechanisms of affordance, and shows how these mechanisms take shape through variable conditions—perception, dexterity, and cultural and institutional legitimacy.

Putting the framework into action, Davis identifies existing methodological approaches that complement it, including critical technocultural discourse analysis (CTDA), app feature analysis, and adversarial design. In today's rapidly changing sociotechnical landscape, the stakes of affordance analyses are high. Davis's mechanisms and conditions framework offers a timely theoretical reboot, providing tools for the crucial tasks of both analysis and design.
Visual Culture
Authors: Boylan Alexis L.
Published: August 2020

How to think about what it means to look and see: a guide for navigating the complexities of visual culture.

The visual surrounds us, some of it invited, most of it not. In this visual environment, everything we see—color, the moon, a skyscraper, a stop sign, a political poster, rising sea levels, a photograph of Kim Kardashian West—somehow becomes legible, normalized, accessible. How does this happen? How do we live and move in our visual environments? This volume in the MIT Press Essential Knowledge series offers a guide for navigating the complexities of visual culture, outlining strategies for thinking about what it means to look and see—and what is at stake in doing so.

Visual culture has always been inscribed by the dominant and by domination. This book suggests how we might weaponize the visual for positive, unifying change. Drawing on both historical and contemporary examples—from Judy Chicago's The Dinner Party and Beyoncé and Jay-Z at the Louvre to the first images of a black hole—Alexis Boylan considers how we engage with and are manipulated by what we see. She begins with what: what is visual culture, and what questions, ideas, and quandaries animate our approach to the visual? She continues with where: where are we allowed to see it, and where do we stand when we look? Then, who: whose bodies have been present or absent from visual culture, and who is allowed to see it? And, finally, when: is the visual detached from time? When do we see what we need to see?
What is the true discharge rate and pattern of the striatal projection neurons in Parkinson’s disease and Dystonia?
Authors: Valsky Dan , Heiman Grosberg Shai , Israel Zvi , Boraud Thomas , Bergman Hagai , Deffains Marc
Published: August 2020

Dopamine and striatal dysfunctions play a key role in the pathophysiology of Parkinson’s disease (PD) and Dystonia, but our understanding of the changes in the discharge rate and pattern of striatal projection neurons (SPNs) remains limited. Here, we recorded and examined multi-unit signals from the striatum of PD and dystonic patients undergoing deep brain stimulation surgeries. Contrary to earlier human findings, we found no drastic changes in the spontaneous discharge of the well-isolated and stationary SPNs of the PD patients compared to the dystonic patients or to the normal levels of striatal activity reported in healthy animals. Moreover, cluster analysis using SPN discharge properties did not characterize two well-separated SPN subpopulations, indicating no SPN subpopulation-specific (D1 or D2 SPNs) discharge alterations in the pathological state. Our results imply that small to moderate changes in spontaneous SPN discharge related to PD and Dystonia are likely amplified by basal ganglia downstream structures.
Structural basis of mitochondrial translation
Authors: Aibara Shintaro , Singh Vivek , Modelska Angelika , Amunts Alexey
Published: August 2020

Translation of mitochondrial messenger RNA (mt-mRNA) is performed by distinct mitoribosomes comprising at least 36 mitochondria-specific proteins. How these mitoribosomal proteins assist in the binding of mt-mRNA and to what extent they are involved in the translocation of transfer RNA (mt-tRNA) is unclear. To visualize the process of translation in human mitochondria, we report ~3.0 Å resolution structure of the human mitoribosome, including the L7/L12 stalk, and eight structures of its functional complexes with mt-mRNA, mt-tRNAs, recycling factor and additional trans factors. The study reveals a transacting protein module LRPPRC-SLIRP that delivers mt-mRNA to the mitoribosomal small subunit through a dedicated platform formed by the mitochondria-specific protein mS39. Mitoribosomal proteins of the large subunit mL40, mL48, and mL64 coordinate translocation of mt-tRNA. The comparison between those structures shows dynamic interactions between the mitoribosome and its ligands, suggesting a sequential mechanism of conformational changes.
The antifungal activity of vapour phase of odourless thymol derivate
Authors: Kubinec Róbert , Blaško Jaroslav , Galbavá Paulína , Jurdáková Helena , Sadecká Jana , Pangallo Domenico , Bučková Mária , Puškárová Andrea
Published: August 2020

Thymol is a substance with a great therapeutic potential possessing antibacterial and antifungal activity, with a characteristic odour that remains long after application but is not pleasant at higher concentrations. In this study, attention has been focused on describing the chemical and biological properties of the simply prepared trimethylsilyl ether of thymol (kubicin). Interestingly, kubicin has similar volatility as thymol, undergoes hydrolysis in the water (moisture; forming thymol and trimethylsilanol) and can be used at 6,000 times higher concentration than thymol without any negative and irritating odour. Kubicin showed diverse fungistatic and fungicidal activities when tested by direct contact assay, or in vapour phase. The volatile vapour of kubicin was effective on all tested fungal strains. These results suggest that vapours of kubicin might provide an alternative way to fight against fungal contamination.
Genetic variations in the drug metabolizing enzyme, CYP2E1, among various ethnic populations of Pakistan
Authors: Ahmed Sagheer , Altaf Nadeem , Ejaz Mahnoor , Zulfiqar Zaira , Janjua Kholood , Festila Dana , Cristina Nicula
Published: August 2020

Genetic polymorphism in cytochrome P450 (CYP) monooxygenase genes is an important source of interindividual variability of drug response. CYP enzyme activities may change as a result of such polymorphisms which then, may affect drug metabolism. This would result in a change in the severity and frequency of adverse effects in addition to the non-responder phenomenon. CYP2E1, a member of CYP superfamily, affects the metabolism of several clinically important drugs such as halothane, paracetamol, etc. Genetic variation inCYP2E1is known to cause significant inter-individual differences in drug response and adverse effects. The degree of genetic variation is found to be different in different populations around the world. The frequencies of two important polymorphisms in theCYP2E1*7C, NC_000010.10:g.135340548A>G (rs2070672) andCYP2E1, NC_000010.10:g.135339244G>C (rs3813865), are not known in the Pakistani population. In the present investigation, 636 healthy human volunteers were screened for these two single nucleotide polymorphism. Our results indicate that about 18% (rs2070672) and 28% (rs3813865) of the Pakistani population has a genotype containing at least one low activity allele. A significant interethnic variation in the frequencies of both the polymorphisms was observed. These results suggest that pharmacogenetics screening for low activity genotypes would be a helpful tool for clinicians when they prescribe medications metabolized by CYP2E1, as a significant fraction of the Pakistani population is expected to have a variable response to these drugs.
A Legislative Agenda for Reducing Existing Disparities in Maternal and Child Health Care in Nigeria
Authors: Nghargbu Rifkatu , Onyimadu Chukwuemeka , Ibe Ezechinyere
Published: August 2020

A key indicator of the SDG goal of attaining Universal Health Coverage is the access to quality essential health care services, access to safe, effective, quality, and affordable essential medicines and vaccines for all. Although The Federal Government of Nigeria has adopted the SDGs, data from UNICEF’s Multiple Cluster survey 2016 – 2017 indicates a severe disparity in health care service coverage among poor women and children who reside in rural areas. To this end, this communication advocates that the National Assembly ensures that 15% - 20% of health expenditure goes to Primary Health Care. Also, the amendment of the NHIS Act to include community based insurance schemes and employ its powers of scrutiny and oversight functions in order to reduce the dearth in Primary Health care facilities in rural areas.
Infectious Complications in Adult ABO-Incompatible Liver Transplantation: Our Preliminary Experience
Authors: Hayashi Hironori , Takamura Hiroyuki , Tajima Hidehiro , Ohbatake Yoshinao , Nakanuma Shinichi , Miyashita Tomoharu , Ninomiya Itasu , Fushida Sachio , Tani Takashi , Ohta Tetsuo
Published: August 2020

The number of ABO-incompatible living donor liver transplantations (ABO-I LDLT) has increased owing to the use of preoperative rituximab for immunosuppression. However, controversy remains regarding adequate immunosuppression owing to rejection and infection. Here, we present 5 cases of our ABO-I LDLT experience, emphasizing rejection and infectious complications, retrospectively. The treatment protocol included prophylactic rituximab followed by plasma exchange prior to transplantation, splenectomy, and immunosuppressive and prophylactic antibiotic regimens after transplantation. Four of the 5 patients also received local infusion therapy via the portal vein. Neither hyperacute nor antibody-mediated rejection occurred. All grafts were functioning well at discharge. Rehospitalization was required for 2 patients due to severe infection within 6 months of transplantation. Invasive aspergillosis was successfully treated in 1 patient, but the other patient died from severe sepsis with overwhelming postsplenectomy infection syndrome. Our results confirm that, although improved immunosuppressive therapy markedly reduces rejection in ABO-I LDLT, it is also associated with an increased risk of various life-threatening infections.
Gastric Endocrine Carcinoma: A New Look at a Rare Tumor From Cases in Japan
Authors: Iwasaki Kenichi , Suda Takeshi , Yamaguchi Hiroshi , Takahashi Kosuke , Watanabe Takafumi , Makuuchi Yosuke , Ota Yoshihiro , Osaka Yoshiaki , Seshimo Akiyoshi , Katsumata Kenji , Tsuchida Akihiko
Published: August 2020

Objective:

We evaluated the clinicopathologic factors associated with gastric neuroendocrine carcinoma (NEC) in patients who underwent surgical resection. Gastric NEC is rare, accounting for only about 0.6% of all malignant gastric tumors. Neither its pathogenesis nor its treatment has been fully established.

Methods:

We assessed 10 patients with gastric NEC who underwent surgical resection in our hospital between September 2007 and June 2019.

Results:

The patients consisted of 9 men and 1 woman, aged 63 to 78 years. The tumors were localized in the upper region (n = 5), middle region (n = 3), and lower region (n = 2). The macroscopic types were evaluated as 0-IIc (n = 3), 1 (n = 3), 2 (n = 1), 3 (n = 2), and 4 (n = 1). The stages were ascertained as IA (n = 3), IIB (n = 3), IIIA (n = 2), IIIB (n = 1), and IIIC (n = 1). Radical resection was performed in all the patients. After surgery, relapse-free survival was achieved in 6 patients. The mean postoperative survival time was 63.5 months. On immunostaining, 6 patients were positive for CD56, and all were positive synaptophysin and chromogranin A. Of the 10 patients, standard-type adenocarcinoma was concomitantly present in 6.

Conclusions:

Some patients with surgically resected gastric NEC survived over a long period, suggesting the usefulness of radical resection. In future studies, the pathogenesis of gastric NEC should be fully clarified, and therapeutic strategies must be further developed.
Cross‐Linked Gold Nanoparticle Composite Membranes as Highly Sensitive Pressure Sensors
Authors: Schlicke Hendrik , Kunze Svenja , Rebber Matthias , Schulz Norbert , Riekeberg Svenja , Trieu Hoc Khiem , Vossmeyer Tobias
Published: August 2020

In this article, highly sensitive differential pressure sensors based on free‐standing membranes of cross‐linked gold nanoparticles are demonstrated. The nanoparticle membranes are employed as both diaphragms and resistive transducers. The elasticity and the pronounced resistive strain sensitivity of these nanometer‐thin composites enable the fabrication of sensors achieving high sensitivities exceeding 10−3 mbar−1 while maintaining an overall small membrane area. Furthermore, by combining micro‐bulge tests with atomic force microscopy and in situ resistance measurements the membranes’ electromechanical responses are studied through precise observation of the concomitant changes of the membranes’ topography. The study demonstrates the high potential of free‐standing nanoparticle composites for the fabrication of highly sensitive force and pressure sensors and introduces a unique and powerful method for the electromechanical investigation of these materials.
Printable Organic‐Inorganic Nanoscale Multilayer Gate Dielectrics for Thin‐Film Transistors Enabled by a Polymeric Organic Interlayer
Authors: Chen Yao , Zhuang Xinming , Goldfine Elise A. , Dravid Vinayak P. , Bedzyk Michael J. , Huang Wei , Facchetti Antonio , Marks Tobin J.
Published: August 2020

Here, a new approach to the layer‐by‐layer solution‐processed fabrication of organic/inorganic hybrid self‐assembled nanodielectrics (SANDs) is reported and it is demonstrated that these ultrathin gate dielectric films can be printed. The organic SAND component, named P‐PAE, consists of polarizable π‐electron phosphonic acid‐based units bound to a polymeric backbone. Thus, the new polymeric SAND (PSAND) can be fabricated either by spin‐coating or blade‐coating in air, by alternating P‐PAE, a capping reagent layer, and an ultrathin ZrOx layer. The new PSANDs thickness vary from 6 to 15 nm depending on the number of organic‐ZrOx bilayers, exhibit tunable film thickness, well‐defined nanostructures, large electrical capacitance (up to 558 nF cm−2), and good insulating properties (leakage current densities as low as 10−6 A cm−2). Organic thin‐film transistors that are fabricated with representative p‐/n‐type organic molecular/polymeric semiconducting materials, function well at low voltages (<3.0 V). Furthermore, flexible TFTs fabricated with PSAND exhibit excellent mechanical flexibility and good stress stability, offering a promising route to low operating voltage flexible electronics. Finally, printable PSANDs are also demonstrated and afford TFTs with electrical properties comparable to those achieved with the spin‐coated PSAND‐based devices.
Rapid 3D Printing of Electrohydraulic (HASEL) Tentacle Actuators
Authors: O'Neill Maura R. , Acome Eric , Bakarich Shannon , Mitchell Shane K. , Timko Julia , Keplinger Christoph , Shepherd Robert F.
Published: August 2020

A comprehensive material system is introduced for the additive manufacturing of electrohydraulic (HASEL) tentacle actuators. This material system consists of a photo‐curable, elastomeric silicone‐urethane with relatively strong dielectric properties (εr ≈ 8.8 at 1 kHz) in combination with ionically‐conductive hydrogel and silver paint electrodes that displace a vegetable‐based liquid dielectric under the application of an electric field. The electronic properties of the silicone material as well as the mechanical properties of the constitutive silicone and hydrogel materials are investigated. The hydraulic pressure exerted on the dielectric working fluid in these capacitive actuators is measured in order to characterize their quasi‐static behavior. Various design features enabled by 3D printing influence this behavior—decreasing the voltage at which actuation begins or increasing the force density in the system. Using a capacitance change of >35% across the actuators while powered, a demonstration of self‐sensing inherent to HASELs is shown. Antagonistic pairs of the 3D printed actuators are shown to exert a blocked force of over 400 mN. An electrohydraulic tentacle actuator is then fabricated to demonstrate the use of this material and actuation system in a synthetic hydrostat. This tentacle actuator is shown to achieve motion in a multi‐dimensional space.
A child with duchenne muscular dystrophy: A case report of a rare diagnosis among Africans
Authors: Nassoro David D. , Torres Liset , Marando Rehema , Mboma Lazaro , Mushi Seraphine , Habakkuk Mwakyula Issakwisa
Published: August 2020

In Africa, lack of awareness and low index of suspicion of rare diseases like dystrophinopathies, directly or indirectly, contributes to the increased morbidity and mortality. Therefore, even though the data on prevalence is limited, we need to have a high degree of suspicion in patients presenting with suggestive clinical features.
Low frequency of parental mosaicism in de novo COL4A5 mutations in X‐linked Alport syndrome
Authors: Helle Ole Magnus Bjorgaas , Pedersen Torkild Høieggen , Ousager Lilian Bomme , Thomassen Mads , Hertz Jens Michael
Published: August 2020

Background

Alport syndrome is a progressive hereditary kidney disease clinically presenting with haematuria, proteinuria, and early onset end‐stage renal disease, and often accompanied by hearing loss and ocular abnormalities. The inheritance is X‐linked in the majority of families and caused by sequence variants in the COL4A5 gene encoding the α5‐chain of type‐IV collagen. The proportion of de novo COL4A5 sequence variants in X‐linked Alport syndrome has been reported between 12 and 15% in previous studies.

Methods

In the present study we have systematically investigated the mosaic status of asymptomatic parents of six patients with X‐linked Alport syndrome using next‐generation sequencing of DNA extracted from different tissues. The deleterious COL4A5 sequence variants in these patients were previously assumed to be de novo, based on Sanger sequencing of the parents.

Results

A low‐grade (1%) parental mosaicism was detected in only one out of six families (17%). In addition, in one out of six families (17%), we found that the mutational event probably occurred postzygotic.

Conclusion

These findings highlight the importance of testing for mosaicism in unaffected parents of patients with sequence variants considered to be de novo, as it may have implications for the recurrence risk and thereby for the genetic counseling of the family.
Supporting Human Autonomy in AI Systems: A Framework for Ethical Enquiry
Authors: Calvo Rafael A. , Peters Dorian , Vold Karina , Ryan Richard M.
Published: August 2020

Autonomy has been central to moral and political philosophy for millennia, and has been positioned as a critical aspect of both justice and wellbeing. Research in psychology supports this position, providing empirical evidence that autonomy is critical to motivation, personal growth and psychological wellness. Responsible AI will require an understanding of, and ability to effectively design for, human autonomy (rather than just machine autonomy) if it is to genuinely benefit humanity. Yet the effects on human autonomy of digital experiences are neither straightforward nor consistent, and are complicated by commercial interests and tensions around compulsive overuse. This multi-layered reality requires an analysis that is itself multidimensional and that takes into account human experience at various levels of resolution. We borrow from HCI and psychological research to apply a model (“METUX”) that identifies six distinct spheres of technology experience. We demonstrate the value of the model for understanding human autonomy in a technology ethics context at multiple levels by applying it to the real-world case study of an AI-enhanced video recommender system. In the process we argue for the following three claims: (1) There are autonomy-related consequences to algorithms representing the interests of third parties, and they are not impartial and rational extensions of the self, as is often perceived; (2) Designing for autonomy is an ethical imperative critical to the future design of responsible AI; and (3) Autonomy-support must be analysed from at least six spheres of experience in order to appropriately capture contradictory and downstream effects.
Cosmological decoherence from thermal gravitons
Authors: Bao Ning , Chatwin-Davies Aidan , Pollack Jason , Remmen Grant N.
Published: August 2020

Abstract

We study the effects of gravitationally-driven decoherence on tunneling processes associated with false vacuum decays, such as the Coleman-De Luccia instanton. We compute the thermal graviton-induced decoherence rate for a wave function describing a perfect fluid of nonzero energy density in a finite region. When the effective cosmological constant is positive, the thermal graviton background sourced by a de Sitter horizon provides an unavoidable decoherence effect, which may have important consequences for tunneling processes in cosmological history. We discuss generalizations and consequences of this effect and comment on its observability and applications to black hole physics.
Analytic continuation of Bethe energies and application to the thermodynamic limit of the SL(2, ℂ) non-compact spin chains
Authors: Granet Etienne , Jacobsen Jesper Lykke , Saleur Hubert
Published: August 2020

Abstract

We consider the problem of analytically continuing energies computed with the Bethe ansatz, as posed by the study of non-compact integrable spin chains. By introducing an imaginary extensive twist in the Bethe equations, we show that one can expand the analytic continuation of energies in the scaling limit around another ‘pseudo-vacuum’ sitting at a negative number of Bethe roots, in the same way as around the usual pseudo-vacuum. We show that this method can be used to compute the energy levels of some states of the SL(2, ℂ) integrable spin chain in the infinite-volume limit, and as a proof of principle recover the ground-state value previously obtained in [1] (for the case of spins s = 0,$$ \overline{s} $$

s
¯

= −1) by extrapolating results in small sizes. These results represent, as far as we know, the first (partial) description of the spectrum of SL(2, ℂ) non-compact spin chains in the thermodynamic limit.
On the Cauchy difference of functions bounded modulo $$\mathbb {Z}$$ on “large” sets
Authors: Jabłońska Eliza
Published: August 2020

Let X be a real Polish vector space, $$D\subset X$$

D
⊂
X

be a universally Baire non-Haar-meager set, and let $$f:X\rightarrow \mathbb {R}$$

f
:
X
→
R

satisfy $$f(x+y)-f(x)-f(y)\in \mathbb {Z}$$

f
(
x
+
y
)
-
f
(
x
)
-
f
(
y
)
∈
Z

for all $$x,y\in X$$

x
,
y
∈
X

and $$f(D)\subset (-\frac{1}{3},\frac{1}{3})+\mathbb {Z}$$

f

(
D
)

⊂

(
-

1
3

,

1
3

)

+
Z

. We prove that there exists a unique linear functional $$L:X\rightarrow \mathbb {R}$$

L
:
X
→
R

with $$f(x)-L(x)\in \mathbb {Z}$$

f
(
x
)
-
L
(
x
)
∈
Z

for $$x\in X$$

x
∈
X

and next we apply it to functionals which are orthogonally additive modulo $$\mathbb {Z}$$
Z
. These new results are topological counterparts to some results of Brzdȩk (Results Math 30:25–38, 1996) and also generalize (to some extent) his results.
Topology optimization for transversely isotropic materials with high-cycle fatigue as a constraint
Authors: Suresh Shyam , Lindström Stefan B. , Thore Carl-Johan , Klarbring Anders
Published: August 2020

We propose a topology optimization method for design of transversely isotropic elastic continua subject to high-cycle fatigue. The method is applicable to design of additive manufactured components, where transverse isotropy is often manifested in the form of a lower Young’s modulus but a higher fatigue strength in the build direction. The fatigue constraint is based on a continuous-time model in the form of ordinary differential equations governing the time evolution of fatigue damage at each point in the design domain. Such evolution occurs when the stress state lies outside a so-called endurance surface that moves in stress space depending on the current stress and a back-stress tensor. Pointwise bounds on the fatigue damage are approximated using a smooth aggregation function, and the fatigue sensitivities are determined by the adjoint method. Several problems where the objective is to minimize mass are solved numerically. The problems involve non-periodic proportional and non-proportional load histories. Two alloy steels, AISI-SAE 4340 and 34CrMo6, are treated and the respective as well as the combined impact of transversely isotropic elastic and fatigue properties on the design are compared.
The rate of dasotraline brain entry is slow following intravenous administration
Authors: Lew Robert , Constantinescu Cristian C. , Holden Daniel , Carson Richard E. , Carroll Vincent , Galluppi Gerald , Koblan Kenneth S. , Hopkins Seth C.
Published: August 2020

Rationale

Drugs that rapidly increase dopamine levels have an increased risk of abuse. Dasotraline (DAS) is a dopamine and norepinephrine reuptake inhibitor characterized by slow oral absorption with low potential for abuse. However, it remains unclear whether intravenous (i.v.) administration would facilitate the rapid elevation of dopamine levels associated with stimulant drugs.

Objective

To assess the kinetics of DAS across the blood-brain barrier and time to onset of dopamine transporters (DAT) inhibition.

Methods

We compared the onset of DAT occupancy and the associated elevation of synaptic dopamine levels in rhesus monkey following i.v. administration of DAS or methylphenidate (MPH) using positron emission tomography (PET). Brain entry times were estimated by reductions in [18F]-FE-PE2I binding to DAT in rhesus monkeys. Elevations of synaptic dopamine were estimated by reductions in [11C]-Raclopride binding to D2 receptors.

Results

Intravenous administration of DAS (0.1 and 0.2 mg/kg) resulted in striatal DAT occupancies of 54% and 68%, respectively; i.v. administered MPH (0.1 and 0.5 mg/kg) achieved occupancies of 69% and 88% respectively. Brain entry times of DAS (22 and 15 min, respectively) were longer than for MPH (3 and 2 min). Elevations in synaptic dopamine were similar for both DAS and MPH however the time for half-maximal displacement by MPH (t = 23 min) was 4-fold more rapid than for DAS (t = 88 min).

Conclusions

These results demonstrate that the pharmacodynamics effects of DAS on DAT occupancy and synaptic dopamine levels are more gradual in onset than those of MPH even with i.v. administration that is favored by recreational drug abusers.