bluuebunny/crossref_metadata_2025_split huggingface dataset:
La demostración automática de teoremas en Geometría elemental y su repercusión didáctica
Authors: Miranda Díaz I. 
Published: June 2021

The relevant role of validatory tasks in the traditional teaching of geometry is currently approached as a mere introduction to logical reasoning. The existence of automatic proof algorithms to any elementary geometry theorem and their recent implementation in computers gives a peculiar character to the kind of reasoning used in this theory —one of the few being decidible— and modifies its educational meaning. On the other hand, the analysis of the way of teaching geometry shows excessive emphasis on training by discovering models, neglecting the building up of theoretical bodies of knowledge. Both facts demand an exploration of new techniques in the teaching of geometric proofs; we describe and analyze the use of educative software (based on A. I. tecnhiques) for automatic proof programs now operating.
Enseñanza y aprendizaje de la modelización
Authors: Martinand J.L. 
Published: June 2021

A general outline of a research program on the teaching/learning of modelization, being carried out at the moment, is presented. Particular reference is made to the difficulties of learning modelization considering the different types of activities, rhythm, etc. which are suitable to help such learning. As an instance, both relationships force -energy and the atomic model were chosen.
Causas de las dificultades de aplicación del teorema de Arquímedes por los alumnos de Enseñanza Media
Authors: Fernández Fernández J. M. 
Published: June 2021

In order to find out the reasons why the students of 2nd year BUP have so much trouble to solve exercises by applying Archimedes' theorem, we have presented them with five questions. From their answers we learn that most of them do not relate the volume of displaced liquid to that of the submerged body, but to its mass or weight. For most of the students the more mass or weight of the submerged body, the more volume of displaced liquid.
Apuntes para una programación didáctica de la astronomía en la Enseñanza Media
Authors: Domènech A. , Domènech T. , Casasus Mª E. , Bella Mª Teresa 
Published: June 2021

Aims, stages and methodology programmed for a secondary school course on Astronomy are discussed. A didactic approach based on the guided -discovery method, exemplified by a model -activity series, is proposed. A model of introduction to the use of the formalisms in Position Astronomy, exemplified by the local celestial sphere, is also included.
Utilización de experimentos grabados en vídeo en la enseñanza de la microbiologia
Authors: Tejedor C. , Leal F. , Chordi A. 
Published: June 2021

This paper describes individualized television instruction involving active Univesity students participation with computer assisted questionary. The experiments on microbial growth and genetics were videotaped. Students collected data directly from the television screen. Student accuracy was found to be excellent. Students found these videotaped experiments with computer assisted questionary an adequate substitute for the laboratory sessions. Videotaped experiments with computer assisted learning, which involve the students directly, are one option to take into account when planning future learning programmes. These have the advantage or providing the student with an experience that tnigth otherwise be too time consuming, expensive, dangerous or complicated to be performed in a traditional laboratory.
Actividad práctica de genética de poblaciones para alumnos de C.O.U.
Authors: Conde Domingo G. 
Published: June 2021

Starting from two populations with identical genic frequencies, one of them being balanced and the other unbalanced, and being their genes represented by «pieces of paper)) that may be taken out at random from a box or bag, we sha!l obtain the same genotypic frequencies in both of them, coinciding with those of the balanced population. Students must deduce the necessary conditions for equilibrium in a population by comparing the different genic and genotypic frequencies of both original populations with the populations resulting from this experiment.
Hacer matemáticas
Authors: Hernán Francisco 
Published: June 2021

Reproductive thinking, the habit of using ready-made answers, has Iwo advantages: it is easier both to reach and to test. Productive thinking, creating new answers and using new organizations is more difficult to teach and needs more time and more dynamic teaching relations. Through the process of two problem -solving situations (one by 14-15 years old pupils and the other by 15-16 years old) some reasons are suggested in this paper which argue in favour of mathematical activities more creative than repetitive.
Extended Cruising The Second Time Around
Authors: Court Kenneth E. 
Published: June 2021

Some years ago, in 1975, I presented a paper and a slide show at an earlier sailing yacht symposium in Annapolis. The subject was a four-year, 28,000 mile cruise I had made in the years 1965 - 1968 most of the way around the world: Hawaii and the South Pacific, New Zealand, Australia's Barrier Reef, the Indian Ocean, the Red Sea, the Mediterranean, including the Greek Islands, an Atlantic crossing to Barbados from the Canary Islands, the Caribbean, and home to the Chesapeake. The paper I wrote then was entitled "Extended Cruising: An Overview" and contained sketches and data from my logs. It was same 55 pages long and talked about many facets of cruising from my vantage point, primarily as seen from the decks of Mamari, the 28 foot ketch I had bought in New Zealand.
Lest Mamari 's size appear too small, which perhaps would make me seen heroic, recognize that in displacement and accomodations Mamari was the equivalent of a 33 foot boat. To dispel one other misconception, be advised that I normally sailed with a crew of two, sometimes more, and only sailed two legs single-handed, of about 500 miles each, one from Tonga to Fiji in the Pacific, the other in the Gulf of Suez and from Port Said to the Greek Islands.
The 1975 paper reflected my background as a naval architect, combined with my experience as a sailor. I told of things I learned from others. I analyzed log data, presented photographs, drawings and tables, and wrote a series of "yarns" such as sailors spin about their travels. The paper is touched with a flavor of the sea, a flavor of talk over run or coffee in a snug anchorage or on a shared night watch. That 1975 paper makes good reading, and much of the information is still valid. It could be reprinted and if there is enough interest l will do so (contact me).
This present paper is a brief look at my experiences on a series of sailing trips, but in particular a one year voyage in a 37 foot yawl from Turkey to the Chesapeake via the West Indies in 1980-81. The paper answers the question posed at the 1975 symposium, would I do the trip again? Then, I thought so, but could not be sure, now my reply is, "of course."
Stress Analysis for Light Alloy 12 M Yacht Structures. Comparison Between a Transverse and a Longitudinal Structure
Authors: Boote Dario , Ruggiero Vincenzo , Sironi Nicola , Vallicelli Andrea , Finzi Bruno 
Published: June 2021

A stress analysis has been carried out for the 12 meter yacht "Azzurra", the Italian Challenger to the America's Cup 1983. Two different structural arrangements have been investigated. One is the existing transverse-framed, and the other is a study in which both longitudinal and transverse stiffeners have been included.
The structural models have been analyzed with two different calculation systems under the same loads. The first method is a classical naval architecture direct calculation, while the second is a Finite Elements Method analysis.
A measurement sea trial to evaluate the stresses in various points of the yacht structure has also been performed on "Azzurra" to obtain a feed-back able to check the results given by the numerical analysis.
Some comments and conclusions on the behaviour of the two types of structure are presented.
Traduire les effets territorialisés de la répression en politique. Aux origines de la réparation communautaire au Maroc (2007-2014)
Authors: Vairel12 Frédéric 
Published: June 2021

À partir de différentes enquêtes de terrain, cet article retrace les origines du programme de réparation communautaire au Maroc, un programme de développement socioéconomique et culturel en faveur de régions dont les populations relient leur situation aux « violations graves des droits humains » perpétrées durant les années 1960 à 1990. Prenant appui sur des travaux de sociologie des problèmes publics, l’article revient sur l’émergence et l’élaboration territorialisées de mesures de « justice transitionnelle ». Pour ce faire, nous analysons la constitution en problème des effets territorialisés de la répression par des acteurs associatifs locaux. Ils qualifient des situations et mettent en cause la présence de centres de détention secrets et l’état social et économique de leurs localités qui en résulterait. Ces acteurs appellent des réponses publiques inscrites dans le territoire particulier du Sud-Est marocain. Ensuite, nous montrons que ces acteurs associatifs proposent une désingularisation nouvelle de la répression : la violence a marqué des territoires et non plus des individus ou des groupes militants. Cette mise en cause entre en résonance avec des problématiques internationales (la « justice transitionnelle » saisie par le développement) et des éléments des trajectoires des commissaires de l’Instance Equité et Réconciliation, la commission vérité marocaine, aboutissant à l’élaboration d’une action publique à l’échelle nationale.
Mechanical and Water Characterization of a Light Concrete Based on Typha Australis
Authors: Abdelhakh Azibert Oumar , Mahamat Abdallah Dadi , Abakar Ali , Gaye Salif 
Published: June 2021

This article is devoted to the study of the mechanical and water properties of concrete of Typha australis. The concrete is achieved by the mixture cattail aggregates with cement, sand and water.
Mechanical study showed that the density and the mechanical compressive strength decreases with the dosage of typha aggregates, and increases with the dosage of cement. However, the values obtained do not allow using this concrete in supporting structures. However, the value obtained is 0.16 MPa for the first series (S1), and 0.26 MPa for the second series (S2), for a high dosage of typha of 3.5% is sufficient for a wall of three meters high can support its own load.
With a constant intrinsic porosity, these aggregates are compressible and porous. This physical condition makes the vegetable particles of typha very lightweight and sensitive to water.
The lightweight concrete became sensitive to water. Increasing the dosage of typha aggregates increase the water absorption of concrete. More than 50% of the water content is absorbed during thirty minutes of immersion. It is therefore strongly recommended to waterproof the wall with typha australis.
Neonatal Lupus and Complete Atrioventricular Block: Case Report in Mexico
Authors: Alvarez Carla Eugenia Arenas , Mireles Juan Carlos Marin , Leal Hebert Israel Flores , Gonzalez Ana Norma Griselda Becerril , Sanchez Carlos Mario Guzman 
Published: June 2021

Aims: To describe a case of neonatal lupus and complete atrioventricular block in Mexico.
Presentation of case: A 38 years old pregnant patient at 28 + 6 weeks of gestational age, diagnosed with systemic lupus erythematosus six years ago, under treatment with hydroxychloroquine and prednisone, this was suspended eight months prior to pregnancy; and resumed at week 20 of gestational age. The ultrasound scan showed alive fetus, female, polyhydramnios and bradycardia. Fetal echocardiography confirmed complete atrioventricular block, without organic and structural alterations at the cardiac level. Furthermore, the immunological panel reports, positive anti-Ro antibodies. At week 33 of gestational age, the patient was admitted to the obstetric emergency room, through colic type pain and 4 cm dilation of the cervix. Alive newborn got vaginally with a weight of 1,990 g, a height of 43 cm and APGAR 8-9. Echocardiography confirmed congenital complete third degree atrioventricular block; without structural abnormalities.
Discussion: Patients with systemic lupus erythematosus, are more likely to have complications during pregnancy. Neonatal lupus is a rare disorder with an incidence of 1:10,000 - 1:20,000 newborns. This is caused by the transplacental passage of maternal autoantibodies anti-SSA / Ro and/or anti-SSB / La. Besides Atrioventricular block is a complication of neonatal lupus, occurring in approximately 2% of newborns of mothers who have SSA or SSB antibodies. The most interesting finding is that 20% fetal mortality has been for this cause.
Conclusion: The described case is important for its rarity. Besides, the imaging findings and immunological panel emphasized the relevance about complete and adequate evaluation of the fetus, in the context of a mother with systemic lupus erythematosus.
In-vivo Antiplasmodial Activity of Sulfadoxine/Pyrimethamine/Doxycycline on Plasmodium berghei Infected Mice
Authors: Georgewill Udeme Owunari , Adikwu Elias 
Published: June 2021

The search for newer antimalarial drug combinations is on the front burner due to rising Plasmodium resistance to some currently used antimalarial drugs. This study examined the antiplasmodial activity of sulfadoxine/pyrimethamine/doxycycline (S/P/D) on mice infected with Plasmodium berghei (P. berghei). Swiss albino mice (25-30 g) inoculated with P. bergei (1x107) were treated with D (2.2 mg/kg), S/P (21.4/10.7 mg/kg), and S/P/D for 4 days. The positive and negative controls were treated with normal saline (0.2 ml) and chloroquine (CQ) (10 mg/kg) for 4 days, respectively. After treatment, blood samples were collected and assessed for parasitemia levels and biochemical parameters. The mice were observed for mean survival time (MST). D, S/P, S/P/D and CQ significantly decreased parasitemia in the curative, prophylactic and suppressive tests at p<0.05; p<0.01, p<0.001 and p<0.001, respectively when compared to negative control. In the curative study, 55.9%, 65.1%, and 81.7% parasitemia inhibitions were produced by D, S/P and S/P/D, respectively whereas CQ produced 75.6 % parasitemia inhibition. D, S/P and S/P/D significantly prolonged MST at p<0.05, p<0.01 and p<0.001 respectively when compared to negative control. Altered serum biochemical markers in P. berghei infected mice were marked by significantly (p<0.001) decreased packed cell volume, red blood cells, hemoglobin, high density lipoprotein cholesterol levels with significantly (p<0.001) increased cholesterol, white blood cells, total cholesterol, low-density lipoprotein cholesterol and triglyceride levels when compared to control. However, D, S/P and S/P/D significantly restored the aforementioned markers at p<0.05, p<0.01 and p<0.001, respectively when compared to negative control. S/P/D may be used as an antimalarial drug.
Mini-review on Natural Disintegrants in Pharmaceutical Formulations
Authors: Kankanamge S. U. , Neranja A. G. K. , Sandarenu K. D. S. 
Published: June 2021

Disintegrants are agents which are integrated to tablets and some encapsulated formulations in order to promote the breakup of the tablet and capsule “slugs” into more small fragments in an aqueous environment which thereafter increment the available surface area and promoting a more rapid release of the drug substance. The development of new excipients for potential use as disintegrant agent in tablet formulations continues to be of interest. This is because different disintegrant agents can be useful in promoting penetration of moisture and dispersion of the tablet matrix and disintegration of tablet has received considerable attention at present as an essential step in obtaining fast drug release. Natural polymers such as starches, gums, mucilage, and dried fruits utilized as binder, diluent, and disintegrants to increase the solubility of poorly water-soluble drug, decrease the disintegration time, and provide nutritional supplement. Natural disintegrants are safe and economical than synthetic disintegrants such as Polyvinylpyrrolidone (PVP). Therefore, in the present review, an attempt has been made to reveal the importance of the natural disintegrants in the pharmaceutical formulations.
Sex disparity in acute myeloid leukaemia with FLT3 internal tandem duplication mutations: implications for prognosis
Authors: Hellesøy Monica , Engen Caroline , Grob Tim , Löwenberg Bob , Valk Peter J. M. , Gjertsen Bjørn T. 
Published: June 2021

Incidence, molecular presentation and outcome of acute myeloid leukaemia (AML) are influenced by sex, but little attention has been directed at untangling sex‐related molecular and phenotypic differences between female and male patients. While increased incidence and poor risk are generally associated with a male phenotype, the poor prognostic FLT3 internal tandem duplication (FLT3‐ITD) mutation and co‐mutations with NPM1 and DNMT3A are overrepresented in female AML. Here, we have investigated the relationship between sex and FLT3‐ITD mutation status by comparing clinical data, mutational profiles, gene expression and ex vivo drug sensitivity in four cohorts: Beat AML, LAML‐TCGA and two independent HOVON/SAKK cohorts, comprising 1755 AML patients in total. We found prevalent sex‐associated molecular differences. Co‐occurrence of FLT3‐ITD, NPM1 and DNMT3A mutations was overrepresented in females, while males with FLT3‐ITDs were characterized by additional mutations in RNA splicing and epigenetic modifier genes. We observed diverging expression of multiple leukaemia‐associated genes as well as discrepant ex vivo drug responses, suggestive of discrete functional properties. Importantly, significant prognostication was observed only in female FLT3‐ITD‐mutated AML. Thus, we suggest optimization of FLT3‐ITD mutation status as a clinical tool in a sex‐adjusted manner and hypothesize that prognostication, prediction and development of therapeutic strategies in AML could be improved by including sex‐specific considerations.
Spin–Spin Interactions in One‐Dimensional Assemblies of a Cumulene‐Based Singlet Biradical
Authors: Hirao Yasukazu , Daifuku Yoko , Ihara Keiji , Kubo Takashi 
Published: June 2021

AbstractThe synthesis of phenalenyl‐endcapped [5]cumulene as a cumulene‐based singlet biradical and the spin correlation changes of one‐dimensional aggregates are described. The high propensity for self‐aggregation of phenalenyl rings and the introduction of bulky substituents into the appropriate positions led to the formation of a one‐dimensional chain assembly. Single‐crystal X‐ray structural analysis indicated that the bond length alternation of the cumulene chain increased with decreasing temperature, along with improved overlapping of the phenalenyl rings. Variable‐temperature Raman spectroscopy and magnetic susceptibility measurements revealed that a localized spin pair within the molecule decouples at low temperatures, and a continuum spin system involving intra‐ and intermolecular spin–spin interactions emerges in the one‐dimensional chain.
DNA barcode analyses improve accuracy in fungal species distribution models
Authors: Fernández‐López Javier , Telleria M. Teresa , Dueñas Margarita , May Tom , Martín María P. 
Published: June 2021

AbstractSpecies distribution models based on environmental predictors are useful to explain a species geographic range. For many groups of organisms, including fungi, the increase in occurrence data sets has generalized their use. However, fungal species are not always easy to distinguish, and taxonomy of many groups is not completely settled. This study explores the effect of taxonomic uncertainty in databases used for modeling fungal distributions. We analyze distribution models for three morphospecies from the corticioid genus Xylodon (Hymenochaetales, Basidiomycota), comparing models based on species names on vouchers specimens with models derived from species identified by DNA barcode. Differences in the contribution of predictors driving the distribution of each modeled taxon and the extent of their ranges were studied. Records under Xylodon paradoxus, X. flaviporus, and X. raduloides were obtained from fungarium collections and GenBank repository. Two grouping criteria were used: (a) specimens were grouped by their collection or sequence voucher names and (b) specimens were grouped following molecular identification using ITS sequences through barcoding gap species recognition (BGSR). Climatic, geographic, and biotic variables were used to predict the potential distribution of each taxon through MaxEnt algorithm. From the three morphospecies selected according to voucher names, up to 19 species candidates were detected using BGSR. Climatic variables were the most important predictors in distribution models made from names on voucher specimens, but their importance decreased when BGSR was applied. In general, the extent of species distributions was more restricted for taxa under BGSR. Our results show that taxonomic uncertainty has a strong effect in Xylodon species distribution models. Misleading results can be obtained when cryptic species or identification errors mask the actual diversity of the presence records. Preserved specimens in natural history collections offer the possibility to assess whether the species name on labels matches the current species recognition criteria.
Age‐group‐specific reference intervals for anti‐Müllerian hormone and its diagnostic performance for polycystic ovary syndrome in a Korean population
Authors: Song Junhyup , Park Yongjung , Cho Hae Weon , Lee Sang‐Guk , Kim Sinyoung , Lim Jong Baeck 
Published: June 2021

AbstractBackgroundWe established age‐group‐specific reference intervals for serum anti‐Müllerian hormone (AMH) levels in a Korean population and investigated the effectiveness of AMH assay for polycystic ovary syndrome (PCOS) diagnosis.MethodsWe analyzed serum levels of AMH, follicle‐stimulating hormone (FSH), and luteinizing hormone (LH) from 1540 Korean women. Subjects were divided into three groups: healthy, benign gynecologic diseases, and PCOS. Age‐group‐specific reference intervals and AMH diagnostic performance were estimated.ResultsThe PCOS group had a median AMH level of 7.0 µg/L, which was higher than for the healthy (1.8 µg/L) and the benign gynecologic diseases (2.7 µg/L) groups. The upper 97.5% reference limits for age groups 12–20 years, 21–34 years, and 35–46 years were 13.2 µg/L, 15.8 µg/L, and 6.6 µg/L, respectively. The area under the curve (AUC) values to estimate AMH ability to discriminate PCOS from healthy women for each age group were 0.741, 0.785, and 0.789, respectively. AUCs for LH/FSH were 0.719, 0.672, and 0.590.ConclusionsThe better diagnostic ability of AMH over LH/FSH in women of late childbearing ages indicates that age and other clinical characteristics should be considered when interpreting these test results.