bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute Kidney Injury Following Primary Knee Replacement; Systematic Review
Authors: Dixon Joe
Published: December 2024

Objectives
Knee Replacement (KR) is a highly-effective procedure for improving pain and function in patients. Acute Kidney Injury (AKI) is a potential complication that is associated with increased length of stay, morbidity and mortality. The aims of this systematic review were to establish the incidence of AKI following primary KR and to characterize risk factors for AKI and the incidence of Renal Replacement Therapy (RRT).
Methods
A systematic review of the literature was undertaken with a search of Medline, Embase, Scopus, Cochrane Library. The review included clinical trials or observational studies (cohort, case-control or cross-sectional studies) reporting the incidence of AKI following primary KR.
Results
1,523 studies were identified in the initial search, with eight meeting the inclusion criteria. A total of 13,574 episodes of patients undergoing primary knee replacement were included. The mean age of patients was 68.91 years (SD 2.68). 11,346 (83.02%) of patients were female. The weighted pooled incidence of AKI in the included studies was 8.85 (95% CI 8.35% to 9.35%). Risk factors highlighted for AKI following primary KR frequently identified were Age >65, Diabetes Mellitus and pre-existing chronic kidney disease. There was limited data on the requirement for RRT.
Conclusion
AKI is one of the most common complications following KR. There is a need for research into interventions that may reduce the risk of AKI.
Self-reported and Pharmacologic Adherence During a Demonstration Project on HIV Pre-exposure Prophylaxis among Men who have Sex with Men in Benin
Authors: Diabaté Souleymane
Published: December 2024

Background and aim. The effectiveness of oral pre-exposure prophylaxis (PrEP) for HIV prevention relies on Adherence. Accordingly, the aim of this study was to compare self-reports that are commonly used in sub-Saharan Africa to monitor adherence with dried blood spots-based results.
Materials and methods. The study was part of an oral PrEP demonstration project conducted from August 2020 to December 2021 among 204 men who have sex with other men in Benin. The Mc Nemar test and bivariate log-binomial regression models using the GENMOD procedure were performed to compare adherence levels and explore the association between pharmacologic adherence and four indicators for oral PrEP initiation in Benin.
Results. Only 46% and 24.3% of men who provided dried blood spots had detectable drugs levels at month-6 and month-12, respectively. At month-6, perfect adherence for daily PrEP was 92% (self-reports) and 10% (pharmacologic measure; p-value<0.0001) and for event-driven, 49% (self-reports) and 31% (pharmacologic measure; p-value=0.008). At month-12, the corresponding values were 94% and 5% (p<0.0001), and 40% and 27% (p=0.005), respectively. In bivariate analyses, the p-values estimating the association between HIV risk factors and pharmacologic perfect adherence (≥1450 fmol/punch) were 0.173 for consistent condom use, 0.303 for NG and/or CT infections, 0.447 for drug or alcohol consumption, and 0.129 for multiple sexual partnership. Similar results were obtained for partial adherence (≥800 fmol/punch). In post-hoc analyses, three HIV seroconversions were observed in men with a pharmacologic drug concentration <400 fmol/punch.
Conclusions. Adherence was generally low and self-reported adherence tended to overestimate pharmacologic adherence. Oral PrEP should be implemented along with continuous adherence support interventions and other HIV prevention tools, including injectable PrEP, so that people can choose the method that adjust the best to their daily life conditions.
Edukasi Strategi Marketing Wirausaha Produk Roti Lapas Batam (ROPASTAM) Warga Binaan Lapas Kelas II Batam
Authors: Amalia Eva , Wardana Rosnendya Wisnu , Rini Rosie Oktavia Puspita
Published: December 2024

Kegiatan pengabdian masyarakat ini bertujuan untuk memberikan edukasi tentang strategi pemasaran wirausaha kepada warga binaan di Lembaga Pemasyarakatan (Lapas) Kelas IIA Batam. Warga binaan yang menjadi fokus kegiatan ini adalah mereka yang terlibat dalam usaha pembuatan roti, dikenal sebagai "Roti Lapas Batam" (Ropastam). Program ini memberikan pelatihan dan bimbingan tentang strategi pemasaran konvensional dan digital, dengan tujuan meningkatkan kemampuan warga binaan dalam memasarkan produk mereka. Produksi roti ini tidak hanya berfungsi sebagai sarana untuk mengurangi stres selama masa tahanan, tetapi juga menjadi bekal keterampilan yang dapat digunakan oleh warga binaan setelah menyelesaikan masa pidana.  Tema strategi marketing wirausaha  dipilih sebagai fokus utama karena potensi untuk memperluas pasar secara signifikan dibandingkan dengan metode pemasaran tradisional. Selain memberikan pengetahuan tentang kewirausahaan, kegiatan ini juga bertujuan untuk membangkitkan minat dan kreativitas warga binaan dalam mengembangkan ide bisnis lainnya di masa depan. Kegiatan ini merupakan bagian dari program pembinaan kemandirian yang diharapkan dapat memberikan kontribusi signifikan dalam mempersiapkan warga binaan untuk menghadapi tantangan di dunia bisnis yang terus berkembang, terutama di era digital. Pada akhirnya, diharapkan warga binaan dapat mandiri secara ekonomi dan aktif berperan dalam pembangunan masyarakat setelah kembali ke lingkungan sosial.
Disolver para materializar: La paradoja en la arquitectura contemporánea y el método CEM
Authors: Carrasco Aparicio Jorge Carlos , Gamarra Sampén Manuel Agustín
Published: December 2024

Introducción: La arquitectura contemporánea enfrenta la paradoja de adaptarse a un mundo en constante cambio e incertidumbre donde la estandarización, predominante sobre la personalización, subraya la necesidad de sistemas adaptables capaces de abordar diversos contextos. Metodología: Este estudio conecta momentos históricos desde la arquitectura moderna hasta la tradición local, proyectándose hacia el futuro. A través del método CEM (Contexto, Experiencia y Manifiesto), se analizan las obras The Crown Hall y KAIT Workshop, que se deconstruyen para generar un nuevo marco teórico. Resultados: El enfoque plantea soluciones innovadoras para los desafíos del entorno construido contemporáneo. Discusión: Se explora la interconexión entre la tradición arquitectónica del movimiento moderno, el contexto local y las necesidades futuras, integrando valores culturales y contextuales en la arquitectura contemporánea. Conclusiones: Esta investigación ofrece una herramienta útil para el oficio, la práctica y docencia en arquitectura buscando enfrentar las complejidades del mundo actual al proyectar soluciones arquitectónicas flexibles y customizadas.
Ecuador post petróleo: Una realidad
Authors: Pilicita Garrido Amparo Isabel , Cruz Rodríguez Mario Alejandro , Suárez Torres Paola Andrea , Montúfar Ruales Francisco Xavier
Published: December 2024

Introducción: Ecuador tiene una larga tradición de exportación petrolera en la Amazonía, pero los ingresos de esta actividad dependen principalmente de la variación del precio del crudo, sin considerar que es un recurso no renovable que se agotará. Metodología: Se empleó una metodología cuantitativa, analizando datos sobre el porcentaje de participación en las exportaciones e importaciones seleccionadas. Resultados: El estudio sugiere que Ecuador debe enfocarse en implementar tecnología para exportar productos con valor agregado, no solo en su forma original. También es clave la transferencia de tecnología y la formación de nuevas generaciones para desarrollar productos como medicamentos. Discusión: Si bien es necesario continuar exportando recursos agrícolas, marítimos y mineros, el enfoque debe ser hacia una “Reforma industrial” que impulse la creación de valor agregado en las exportaciones. Conclusiones: Ecuador debe invertir en innovación tecnológica y educación para diversificar sus exportaciones y reducir la dependencia del petróleo, creando una economía más sostenible.
El podcast como medio de acercamiento a los Estudios Culturales y al cine estadounidense
Authors: Illanes Vicioso Pilar
Published: December 2024

Introducción: La forma de consumir cine y televisión ha cambiado gracias a las plataformas digitales. Del mismo modo, el podcast se ha convertido en un exitoso método de comunicación de masas. Aunando ambos elementos, este proyecto espera motivar al alumnado a acercarse a los Estudios Culturales a través del cine estadounidense. Metodología: Durante las clases se empleará el método de aprendizaje experiencial, centrándose sobre todo en el modelo diseñado por David Kolb. Discusión: Los retos principales que plantea este proyecto se centran en no confundir su desarrollo con la impartición de clases magistrales sobre Estudios Culturales y cine, y en garantizar que los miembros de un mismo grupo colaboren de forma justa y equitativa. Conclusiones: A través de este proyecto se espera que el alumnado mejore su capacidad de pensamiento crítico, y despertar su interés por los Estudios Culturales y el potencial de la cultura popular.
Cellular concrete with variable density from Vietnam raw materials
Authors: Lam Tang Van , Luong Pham Duc , Trong Vo Dinh , Bulgakov B. I. , Bazhenova S. I.
Published: December 2024

The existing methods of obtaining cellular concrete products with a variatropic structure are analyzed. It is revealed that each of them has its own advantages and disadvantages. A new technology for the production of cellular concretes of variable density has been developed, which makes it possible to manufacture construction products in Vietnam from local raw materials with high performance characteristics and meeting modern requirements for energy efficiency and durability.According to the test results, it was found that at the hardening age of 28 days, the average density in the dry state and in the state of normal humidity is in the range of 1085–1608 and 960–1517 kg/m3, respectively. Strength tests have shown that the developed concrete reaches an average compressive strength of 13.5–25.4 MPa on the 28th day of hardening. It can be concluded that the combination of foam and gas-forming components used in the formulation made it possible to obtain cellular concrete with an anisotropic structure, having the required indicators of compressive strength and average density in a wet state, which will be in demand in Vietnam during the construction of facilities for various purposes.
La Terre d’Émile Zola ou l’impossible jacquerie
Authors: Castex Agathe
Published: December 2024

Cet article se propose d’analyser La Terre (1887), le quinzième tome des Rougon-Macquart, dans une perspective politique. Zola place son intrigue dans un contexte de crise agricole qui affecte les conditions de vie de la classe paysanne. Il pose alors la question de la possibilité, en cette seconde moitié de XIXe siècle, d’une « jacquerie » qui mettrait fin à la misère. Cependant, jamais le soulèvement ne se réalise. Sous la plume de Zola, les paysans n’ont aucune velléité d’agir collectivement. Le roman se présente comme une analyse profonde des causes de la désunion des forces. L’instauration du partage des terres sous la Révolution et l’inefficacité des discours révolutionnaires, tournés en dérision, apparaissent comme les raisons principales de l’attentisme qui caractérise les paysans. Mais le souffle de la révolte ne s’éteint pas pour autant : les personnages subversifs recourent à des moyens alternatifs qui garantissent la circulation du discours contestataire.
Une écriture réfractaire. Poétiques insurrectionnelles et crise de la représentation dans les romans de Jules Vallès, Octave Mirbeau et Georges Darien
Authors: Garnault Paul
Published: December 2024

Les romans de Jules Vallès, Octave Mirbeau et Georges Darien ont en commun de mettre en doute la représentation du monde proposée par les fictions contemporaines, particulièrement naturalistes. Instruisant le procès d’une mimesis jugée trompeuse et dangereuse, d’une langue suspecte d’être partisane et dévoyée, les trois hommes élaborent, dans le creuset de l’écriture romanesque, une écriture dont nous essaierons de mettre en lumière les enjeux à la fois esthétiques et politiques. Nous montrerons que cette écriture mobilisant un rire profondément transgressif se caractérise par une exploration des limites formelles, morales et sociologiques. Jouant avec les limites du supportable, éprouvant inlassablement le lecteur, les trois écrivains font de la grimace le socle d’une figuration authentique du réel, fondée sur la justesse du sentiment et sur l’authenticité de la colère.
The Path to Achieving Universal Healthcare in India
Authors: Seksaria Snigdha
Published: December 2024

The Planning Commission of India defines universal health coverage as “equitable access for all Indian citizens regardless of income level, social status, gender, caste or religion, to affordable, accountable, appropriate health services of assured quality (promotive, preventive, curative and rehabilitative) as well as public health services addressing the wider determinants of health with the government being the guarantor and enabler, although not necessarily the only provider, of health and related services. The journey towards universal healthcare formally began, as far back in 1948, under Article 25 of the United Nations’ Universal Declaration of Human Rights. Despite being home to one-sixth of the world’s population, India is still in the early stages of providing a form of comprehensive healthcare to her citizens and needs to take urgent action if she wants to realize her dream of being counted amongst the world’s foremost developed nations. Despite maintaining a high economic growth rate for the past two decades, India lags behind other low-middle income countries with a consistently high out-of-pocket spend. This article explores various aspects of the path achieving universal healthcare in India, including consensus around health financing, regulating, monitoring and community empowerment, with a focus on the debate between private and public provision of universal healthcare. For India, still in the infancy of its health care revolution, this means a long and drawn-out battle that will require increased political, public and social momentum, to inch the country ever-so closer to that fabled-state of Utopia.
“Local floras of Russia” dataset in open access
Authors: Seregin A. P. , Bochkov D. A. , Marchenkova K. Y. , Magazov Y. O. , Dudov S. V. , Chepinoga V. V.
Published: December 2024

For the purpose of the Atlas of the Russian Flora production, we converted data from floristic checklists published in 636 sources from 1975 to 2023 into e-form. We gave preference to complete floristic checklists, however for some areas with low data density partial lists, route records, vegetation relevés and reviews, and in some cases, scattered publications with floristic records also served as data sources. As of April 4, 2024, the Local Floras of Russia dataset (doi: 10.15468/rxtjt2) contains 682,130 plant records from 3,297 geographic locations. The geographic coordinates and georeferencing accuracy are indicated for all species within each floristic list. The average georeferencing accuracy is 28 km. Open access to the database is provided through the GBIF, which allows users to download it either as a whole or in parts, in tabular form. New sources are continuously incorporated into the database.
Comportamiento agronómico de cuarenta y un cruces interclonales de cacao (Theobroma cacao L.) en Ecuador
Authors:   Universidad Técnica Estatal de Quevedo, Vera-Chang Jaime Fabián , Herrera-Tamayo Nataly Lorena ,   Universidad Técnica Estatal de Quevedo, Alvarez-Sanchez Ana Ruth ,   Universidad Técnica Estatal de Quevedo, Alvarez-Aspiazu Andry Annabel ,   Universidad Técnica Estatal de Quevedo, Díaz-Campozano Edison Geovanny ,   Universidad Técnica Estatal de Quevedo, Vásquez-Cortez Luis Humberto ,   Universidad Técnica de Babahoyo
Published: December 2024

La producción de cacao en Ecuador enfrenta dificultades para identificar clones que sean altamente productivos y que cumplan con los estándares internacionales de calidad física y sanitaria. Este tipo de estudios es crucial para Identificar clones con alto rendimiento y calidad, para mejorar la competitividad del cacao ecuatoriano, en el mercado global, razón, por la cual, esta investigación tuvo por objetivo evaluar el comportamiento agronómico de 41 cruces interclonales de cacao, para identificar materiales genéticos superiores. La investigación se realizó en la Finca Experimental “La Represa” en Los Ríos, Ecuador, utilizando un diseño completamente al azar, con 41 tratamientos y dos repeticiones. Se evaluaron variables productivas, sanitarias, de calidad física y la calidad del grano, mediante prueba de corte, clasificada según la norma INEN–17. En cuanto a los resultados, los tratamientos T2, T34 y T33 lograron los mayores índices productivos, aunque con costos elevados, por la mano de obra; en calidad física, el tratamiento T16 tuvo el mayor índice de semilla y T3 y T8 mostraron los valores más altos en espesor de lomo y espesor del surco, respectivamente. El tratamiento T31 alcanzó un 92,50 % de fermentación en la prueba de corte, clasificándose en la categoría ASSPS, la más alta, según la normativa.
Improving Mathematical Reasoning Skills Through an Open-Ended Approach Assisted by Google Classroom and Google Meet
Authors: Trisnawati Nika Fetria , Setyo Arie Anang , Sundari Sundari , Warlatu Abigael
Published: December 2024

Penelitian ini bertujuan untuk meningkatkan kemampuan penalaran matematis siswa melalui pemanfaatan Google Classroom dan Google Meet. Subjek penelitian adalah 21 siswa kelas XI SMK Negeri 2 Kota Sorong. Penelitian ini dilakukan dalam dua siklus, yaitu siklus I dan siklus II, dengan pendekatan penelitian tindakan kelas. Data dikumpulkan melalui penilaian hasil belajar dan observasi kelas, lalu dianalisis secara kuantitatif dan kualitatif. Hasil penelitian menunjukkan adanya peningkatan kemampuan penalaran matematis siswa pada berbagai indikator, yaitu: menyajikan proposisi dan ilustrasi matematika tertulis (47,43%-85,89%), melaporkan dan memanipulasi tuduhan matematika (36,80%-77,77%), menyusun data dan memberikan justifikasi solusi (44,20%-81,40%), serta mencapai kesimpulan (28,12%-47,39%). Rata-rata respons positif siswa terhadap pendekatan open-ended mencapai 9,5%. Berdasarkan temuan ini, pendekatan open-ended yang didukung oleh Google Classroom dan Google Meet terbukti efektif untuk meningkatkan kemampuan penalaran matematis siswa. Implikasi dari penelitian ini adalah bahwa integrasi teknologi dengan pembelajaran berbasis open-ended dapat diterapkan secara lebih luas untuk meningkatkan kualitas pembelajaran matematika di sekolah, terutama dalam situasi pembelajaran jarak jauh.
This study aims to improve students' mathematical reasoning ability using Google Classroom and Google Meet. The subjects of the study were 21 grade XI students of SMK Negeri 2 Sorong City. This study was conducted in two cycles, namely cycle I and cycle II, with a classroom action research approach. Data was collected through assessment of learning outcomes and classroom observations, then analyzed quantitatively and qualitatively. The results of the study showed an increase in students' mathematical reasoning ability in various indicators, namely: presenting written mathematical propositions and illustrations (47.43%-85.89%), reporting and manipulating mathematical accusations (36.80%-77.77%), compiling data and providing justification for solutions (44.20%-81.40%), and reaching conclusions (28.12%-47.39%). The average positive response of students to the open-ended approach reached 9.5%. Based on these findings, the open-ended approach supported by Google Classroom and Google Meet has proven effective in improving students' mathematical reasoning skills. The implication of this study is that the integration of technology with open-ended learning can be applied more widely to improve the quality of mathematics learning in schools, especially in distance learning situations.
Conceptual Knowledge through Instruction Interactive Teaching Materials Integrated Augmented Reality
Authors: Sudirman  , Luritawaty Irena Puji , Bonyah Ebenezer
Published: December 2024

Konsep luas permukaan dan volume 3D merupakan salah satu konsep penting untuk membangun pengetahuan matematis lainnya yang lebih aplikatif. Namun, siswa kesulitan dalam memahami konsep tersebut. Perlu adanya teknologi yang dapat membantu siswa, misalnya Augmented Reality (AR). Penelitian ini bertujuan mengungkap peningkatan pemahaman konsep luas permukaan dan volume prisma melalui Instruction Interactive teaching materials integrated Augmented reality (I-ITMIAR). Desain penelitian yaitu exploratory case study terhadap 32 siswa dan satu guru matematika di salah satu sekolah menengah pertama di Kabupaten Indramayu. Data penelitian diperoleh dari wawancara, observasi, dan tes. Data dianalisis secara kualtiatif menggunakan analisis konten dan statistik deskriptif. Hasil penelitian menunjukkan penggunaan AR memberikan peningkatan signifikan dalam pemahaman siswa terhadap konsep-konsep geometri, khususnya luas permukaan dan volume prisma. Melalui visualisasi tiga dimensi yang dihasilkan, siswa dapat melihat dan berinteraksi dengan model prisma secara real-time. Penggunaan AR dapat menjadi alat bantu efektif umeningkatkan pemahaman konsep.
The concept of 3D surface area and volume is one of the important concepts for building other more applicable mathematical knowledge. However, students have difficulty in understanding the concept. There needs to be technology that can help students, such as Augmented Reality (AR). This study aims to reveal the increase in understanding of the concept of surface area and volume of prisms through Instruction Interactive teaching materials integrated Augmented reality (I-ITMIAR). The research design is an exploratory case study of 32 students and one mathematics teacher at a junior high school in Indramayu Regency. Research data were obtained from interviews, observations, and tests. Data were analyzed qualitatively using content analysis and descriptive statistics. The results showed that the use of AR provided a significant increase in students' understanding of geometric concepts, especially the surface area and volume of prisms. Through the resulting three-dimensional visualization, students can see and interact with the prism model in real-time. The use of AR can be an effective tool to improve conceptual understanding.
The effect of icariin on the stereological parameters of mice's kidneys treated with acrylamide
Authors: Hosseini Mohammad , Pouratzari Majid , Anuri Morteza , Abbasi Abolqasem , Razavi Farnoosh
Published: December 2024

Introduction: Acute kidney injury, a leading cause of kidney failure, can be triggered by toxic substances such as acrylamide. Herbal medicines, known for their antioxidant properties may help reduce the harmful effects of acrylamide. 
Objectives: This study aims to explore the antioxidant effects of icariin, a natural plant product, on the side effects of acrylamide on the stereological changes in kidney tissue in mice.
Materials and Methods: In an experimental study, 32 male mice were randomly divided into 4 groups: intact control, icariin control (dose (100mg/kg/day; acrylamide control) dose 10mg/kg/day); Acrylamide treatment group (10mg/kg/day + Icarrin with a dose of 100mg/kg/day; all substances were administered orally for five weeks. At the end of the fifth week, the animals were anesthetized and ethically euthanized, and their kidneys were subsequently removed. Biometric indicators such as kidney length, changes in kidney thickness, and weight were examined before the kidneys were fixed in formalin. Tissue sections were prepared and analyzed using the H & E method after staining. Stereological indices, including changes in kidney volume, cortex volume, medulla volume, the ratio of glomerulus to cortex surface, and the ratio of renal tubules to cortex surface, were then calculated. The data was analyzed using SPSS version 21 statistical software.
Results: Biometric indicators such as kidney length and thickness, as well as stereological indicators like kidney volume, cortex volume, and medulla volume, showed a statistically significant decrease in the acrylamide group compared to the control and treatment groups (P<0.05). These findings were consistent with the histopathological results observed in the studied groups.
Conclusion: Acrylamide leads to a reduction in both biometric and stereological indicators of kidney health, while the use of icariin potentially mitigates these negative effects. Further studies are necessary to determine the efficacy of icariin in alleviating renal complications caused by acrylamide.
Keywords: Icarrin, Acrylamide, Kidney, Stereological parameters, Biometric parameters
Türkiye’de Yükseköğretime Erişim: Ön Lisans ve Lisans Programlarına Yönelen Öğrenci Talebinin Yapısı (1997-2023)
Authors: Arlı Alim
Published: December 2024

Bu makalede 1997-2023 yılları arasında Türkiye’de yükseköğretim diploma derece programlarına başvuru, yerleşme ve yerleşememe eğilimleri ve yıllar içindeki değişimleri incelenmektedir. Orta öğretimden yüksek eğitime geçiş istatistiklerinden hareketle yükseköğretime erişimin makro düzey betimsel ve keşifsel bir tahlili yapılmaktadır. Türkiye’de yükseköğretime yönelik talep son yüzyılda kesintisiz şekilde artmıştır. 1997 ile 2023 arasındaki yıllar, kurum ile öğrenci yerleştirme kontenjan sayılarının arttığı ve farklı yükseköğretim program türlerinde kapsamlı bir örgütsel genişleme yaşandığı yükseköğretimin kitleselleştirilmesi siyasasının en çarpıcı evresidir. Makale bu genişlemenin farklı lise ve program türleri açısından sonuçlarını sorgulamaktadır. Genel liseler, seçici liseler ve meslek liselerinin bu süreçte yükseköğretime ne türden bir yerleşme eğilimi sergiledikleri incelenmektedir. Ayrıca farklı program türlerinin (ön lisans, açık ve uzaktan öğretim ve lisans) yıllar içinde hangi başvuru profiline sahip aday öğrenciler tarafından tercih edildiği analiz edilmektedir. Yükseköğretim kontenjan sayılarındaki arz ile yükseköğretime giriş sınavlarına giren öğrenci sayıları arasındaki fark zaman içinde açık kalmıştır. Sınavlara başvuran öğrenci sayısındaki yüksekliğin yükseköğretime erişimde bir baskı etkeni olarak yıllar içinde kalıcılığını koruduğu görülmektedir. Farklı lise türleri arasında seçici lise grubu sistem içinde baskın konumunu pekiştirmiştir. Meslek lisesi mezunlarının yerleşmelerdeki başarı düzeylerinin düşük düzeyde kaldığı ve mezunlarından yükseköğretime yerleşenlerin ağırlıkla ön lisans programlarına yerleştikleri görülmektedir. Bir diğer sonuç, bir yükseköğretim programına yerleşenler içinde mezun olup daha önce yerleşmemiş beklemeli adayların son yıllarda son sınıf düzeyinde yerleşen adaylardan daha ağırlıklı kategori oluşturmaktadır. Artan kontenjanlar ve büyüme eğilimi 2016 sonrasında durağanlaşmıştır. Kontenjan kapasitesindeki mevcut durağanlık, 2007 öncesi yükseköğretime erişimdeki arz ile talep arasındaki dengesiz duruma dönüşün bir işaret olarak görülebilir. Erişimdeki genişlemeye rağmen Türk yükseköğretim sisteminin yıllar içinde arz-talep uyumsuzluğu yapısından kurtulamadığı görülmektedir.
The homogenization of Stokes flows in random porous domains of general type
Authors: Beliaev Alexei
Published: December 2024

A new proof of the Darcy law is proposed in the framework of the homogenization theory. The starting point of the homogenization is an unsteady flow of compressible viscous liquid through a small‐scaled random porous domain. This non‐stationary microscopic flow is described by the Stokes equations supplemented by zero boundary conditions for the velocity field. The Darcy law is established for the leading term of the solution. The main geometric assumption on the structure is the connectedness of the porous domain. The set of assumptions contains neither a regularity of boundaries nor any quantitative properties appertaining to the connectedness.
Classification of well‐posed kinetic layer problems II: The index formula
Authors: Golse François , Martel Valérie
Published: December 2024

In the kinetic theory of gases, half‐space problems are important because they govern the behavior of correctors to the Hilbert expansion near the boundaries. This paper takes up the discussion in Coron et al., Comm. Pure Appl. Math. 41 (1988) by a different method, based on the index formula for Wiener–Hopf operators on the half‐line. This method leads naturally to a new result on analogues of Chandrasekhar’s $H$ function, which does not seem easy to obtain by the energy method of Coron et al. (1988).
Approximation of the quasigeostrophic system with the primitive systems
Authors: Iftimie Dragoş
Published: December 2024

In this paper we show that the quasigeostrophic system is well approximated by the primitive systems. More precisely, we prove that if the initial data are weakly well‐prepared then the maximal time existence of the regular solution of the primitive system goes to infinity and the regular solution goes to the solution of the quasigeostrophic system, strongly on an arbitrary time interval. By weakly well‐prepared initial data we mean that the initial data of the primitive systems is converging to an initial data with zero oscillating part, without any assumptions on the speed.
Blow‐up profile for radial solutions of the nonlinear heat equation
Authors: Ramiandrisoa Arthur
Published: December 2024

Assuming that the maximal classical solution $u$ of $u_t-\Delta u=u^p$ on $B(0,R)$ has, at time $T_{\max}$ , a blow‐up set $\mathbf{B}(u)$ that is not the singleton $\left\{0\right\}$ , we prove that ${\|u\|}_{L^q (\varOmega)}$ blows up for all $q>(p-1)/2$ , the energy blows up and $u$ blows up completely after $T_{\max}$ in the sense of Baras–Cohen (equivalent to the fact that there is no weak solution extending $u$ beyond $T_{\max}$ ). We also study this type of blow‐up through numerical experiments as well as degenerate blow‐up.
Determining asymptotics of magnetic fields from fixed energy scattering data
Authors: Joshi Mark S. , Sá Barreto Antônio
Published: December 2024

The problem of recovering the asymptotics of a short range perturbation of the Euclidean Laplacian on $\mathbb{R}^n$ from fixed energy scattering data is studied. It is shown that for $n \geq 3$ the asymptotics of a magnetic potential are determined, modulo Gauge invariance, by its scattering matrix at a fixed non‐zero energy. This result also holds for a wide class of scattering manifolds.
Asymptotic analysis of a turbine blade[1]This work has been partially supported by Project XUGA11601A97 of Xunta de Galicia, Spain.
Authors: Rodríguez José M.
Published: December 2024

In this paper we obtain a limit model for a turbine blade fixed to a 3D solid. This model is a three‐dimensional elasticity problem in the 3D part of the piece (the rotor) and a two‐dimensional problem (the shallow shell equations) in the 2D part (the turbine blade), with junction conditions in the part of the turbine blade fixed to the rotor. To obtain this model we shall do an asymptotic analysis, starting with the linear three‐dimensional elasticity equations on all the piece and taking as a small parameter the thickness of the blade. Finally, we shall make some comments about what happens in the nonlinear case.
Asymptotic behaviour of solutions of Maxwell’s equations in exterior domains
Authors: Jochmann Frank
Published: December 2024

In this paper the long time asymptotic behavior of solutions of Maxwell’s equations with electric conductivity in an exterior domain with mixed boundary conditions is investigated. It is shown that the solution behaves asymptotically like a free space solution provided it obeys a suitable local decay property. As a consequence, the completeness of the wave operators is obtained under very general assumptions on the coefficients.
On the decay estimates for elasticity systems with some localized dissipations
Authors: Guesmia Aissa
Published: December 2024

We prove some precise decay estimates of the energy for non‐isotropic elastodynamic systems with some localized dissipations. The damping is nonlinear and is effective only in a neighborhood of a suitable subset of the boundary, we study both degenerate and nondegenerate cases. The method of proof is direct and is based on the multiplier technique and on some specific integral inequalities.
Nonstationary models for shallow lakes
Authors: Bresch Didier , Lemoine Jérôme , Simon Jacques
Published: December 2024

In this paper we study the behaviour of solutions of Navier–Stokes equations with adherence to the bottom and traction by wind at the surface when the aspect ratio $\delta=\hbox{depth}/\hbox{lenght}$ of the domain tends to 0. Precisely, we prove that when wind is moderate, a variational solution converges to the solution of a vertical diffusion model. This model is either quasistationary or nonstationary, according to the characteristic time.
Γ‐convergence of stratified media with measure‐valued limits
Authors: Gustafsson Björn , Heron Bernard , Mossino Jacqueline
Published: December 2024

We consider energy functionals, or Dirichlet forms, [Formula: see text] for a class $\mathcal{G}$ of bounded domains $\varOmega\subset\mathbb{R}^N$ , with $\varepsilon >0$ a fine structure parameter and with symmetric conductivity matrices $A^\varepsilon=(a^\varepsilon_{ij})\in L_\mathrm{loc}^\infty(\mathbb{R})^{N\times N}$ which are functions only of the first coordinate $x_1$ and which are locally uniformly elliptic for each fixed $\varepsilon>0$ . We show that if the functions (of $x_1$ ) $b^\varepsilon_{11}={1}/{a^\varepsilon_{11}}$ , $b^\varepsilon_{1j}={a^\varepsilon_{1j}}/{a^\varepsilon_{11}}\ (j\geq 2)$ , $b^\varepsilon_{ij}= a^\varepsilon_{ij} - {a^\varepsilon_{i1}a^\varepsilon_{1j}}/{a^\varepsilon_{11}} \ (i, j\geq 2)$ converge weakly* as measures towards corresponding limit measures $b_{ij}$ as $\varepsilon\to 0$ , if the $(1,1)$ ‐coefficient $m_{11}^\varepsilon$ of $(A^\varepsilon)^{-1}$ is bounded in $L_\mathrm{loc}^1(\mathbb{R})$ and if none of its weak* cluster measures has atoms in common with $b_{ii}$ , $i\geq 2$ , then the family $J^\varepsilon=\{J_\varOmega^\varepsilon \}_{\varOmega\in \mathcal{G}}$ $\varGamma$ ‐converges in a local sense towards a naturally defined limit family $J=\{J_\varOmega \}_{\varOmega\in \mathcal{G}}$ as $\varepsilon\to 0$ . An alternative way of formulating the conclusion is to say that the energy densities $(A^\varepsilon\nabla u,\nabla u)$ $\varGamma$ ‐converge in a distributional sense towards the corresponding limit density.

Writing $J_\varOmega^\varepsilon$ in terms of $B^\varepsilon=(b_{ij}^\varepsilon)$ it becomes [Formula: see text] and the definition of $J_\varOmega$ and the limit density $(A\nabla u,\nabla u)$ is obtained by properly replacing the $b^\varepsilon_{ij}\in L_\mathrm{loc}^\infty (\mathbb{R})$ by the limit measures $b_{ij}$ and making sense to everything for $u$ in a certain linear subspace of $L_\mathrm{loc}^2(\mathbb{R}^N)$ .
Initial trace for a porous medium equation: II. The critical absorption term
Authors: Chasseigne Emmanuel
Published: December 2024

We consider the following non linear diffusion equation with critical absorption exponent: $u_{t}-\Delta u^{m}+u^{m}=0$ , $m>1$ , in a bounded set $\varOmega $ and in $\mathbb{R}^{N}$ . In the whole space, we give optimal conditions on measure initial data to have existence and uniqueness, and we study singular solutions, which explode in $\varOmega $ when $t\rightarrow0$ . The problem of the initial trace is also completely addressed, and we derive estimates for the initial trace of continuous solutions.
Propagation and absorption of concentration effects near shock hypersurfaces for the heat equation
Authors: Fermanian Kammerer C.
Published: December 2024

In this paper we study families of solutions to heat equation with a small parameter and a propagation term consisting in a discontinuous vector field b through a smooth compact hypersurface S. Our purpose is to describe the evolution of the energy density as h goes to 0 of a family of solutions for a bounded square integrable family of inital data. Outside of S it is classical to calculate this limit by using semi‐classical measures associated with the family of solutions. The discontinuity of b through S induces a difficulty that we overcome provided a second microlocalization. We introduce two‐microlocal items describing the concentration of a square integrable bounded sequence on a hypersurface. By using these items we calculate for convenient times semi‐classical measures of the family of solutions in the whole cotangent space and the limit of the energy density as small parameter goes to 0.
Constructive Borel–Ritt interpolation results for functions of several variables
Authors: Hernández Jesús A. , Sanz Javier
Published: December 2024

We give constructive proofs for two Borel–Ritt interpolation results, stating the existence of holomorphic functions on polysectors admitting an arbitrarily prescribed asymptotic expansion, whether in the sense of Gérard–Sibuya or in that of Majima. As a consequence, a new proof is obtained for the classical Borel's theorem on the existence of 𝒞∞ functions on $\mathbb{R}^{n}$ with given derivatives at 0; in fact, our construction provides functions analytic in $(\mathbb{R}-\{0\})^{n}$ .
Scattering problems for a canonical system with a pseudo‐exponential potential
Authors: Gohberg I. , Kaashoek M.A. , Sakhnovich A.L.
Published: December 2024

Scattering problems are solved for a canonical differential system with a pseudo‐exponential potential v. The latter means that v is defined in terms of a triple consisting of an n×n matrix β and two n×m matrices γ1 and γ2 satisfying β*−β=iγ2γ2 *, via the formula v(x)=−2iγ1 *eixα*Σ(x)−1eixαγ, γ=−(γ1+iγ2), where α=β−γ1γ2* and the matrix function Σ is given by Σ(x)=In+∫0xΛ(t)Λ(t)* dt, Λ(x)=[e−ixαγ1 eixαγ].

Such a potential may not be summable. Explicit formulas are presented for the scattering function and the reflection coefficient of the system, and for other functions defined in terms of the asymptotic properties of the fundamental solution of the corresponding differential system. The corresponding inverse problems are also solved explicitly. The state space method from algebraic system theory is used as a basic tool. The results extend those in [11, 2, 5, 4].
An existence result for a model of granular material with non‐constant density
Authors: Gwiazda Piotr
Published: December 2024

We consider a model developed by Savage and Hutter [17,18], which describes the flow of granular avalanches down a smoothly varying slope. The system consists of two nonstrictly hyperbolic equations for height and momentum.

The existence of entropy solutions to this model is proved using the vanishing viscosity method, where we make extensive use of a generalised version of the invariant region theorem in order to prove a priori estimates. Since the model has a discontinuous source term, a new definition of entropy solution must be introduced.
On homogenization of networks and junctions
Authors: Chechkin Gregory A. , Jikov Vasili V. , Lukkassen Dag , Piatnitski Andrey L.
Published: December 2024

In the paper we propose a new approach to the homogenization theory on periodic wire‐networks and junctions, based on singular measures on these structures. We characterize the Sobolev spaces on such constructions and describe the fields of potential and solenoidal (divergence free) vector‐function. Then we compare the effective coefficients obtained for the singular structures and the classical effective coefficients for thin constructions with vanishing thickness, and show that the corresponding diagram is commutative.
Vibrations of elastic systems with a large number of tiny heavy inclusions
Authors: Rybalko Volodymyr
Published: December 2024

We consider a spectral problem modeling natural vibrations of a complex medium consisting of an elastic medium and tiny rigid inclusions. We study the asymptotic behaviour of the eigenvalues and eigenvectors of this problem when the total number of inclusions and their density tend to infinity. We obtain a limiting problem, that is a spectral problem for a linear fractional operator pencil, describing the macroscopic behaviour of the system (global vibrations). We also show that there exist vibrations of the medium localized in small vicinities of the inclusions (local vibrations), which correspond to eigenvalues accumulating at the poles of the operator pencil.
Homogenization of the transient Reynolds equation
Authors: Buscaglia G. , Ciuperca I. , Jai M.
Published: December 2024

State‐of‐the‐art magnetic storage devices have head‐to‐disk distances of about 300 Angstrom, for which compressibility, slip‐flow and roughness effects are significant. Since the head and the disk are in relative motion, the air‐gap thickness when both surfaces are rough varies rapidly in both space and time. A rigorous homogenization of the transient compressible Reynolds equation appropriate for such situation is presented in this article. If ε is the roughness length and pε the pressure field for that roughness, the existence of p0∈L2(0,T,H1(Ω)) such that pε→p0 strongly in L2(Ω×]0,T[) when ε→0 is proved.

A homogenized problem for p0 is introduced together with a uniqueness result under remarkably weak assumptions, i.e., p0∈L2(0,T,H1(Ω)) and ∂p0/∂t∈L2(0,T,H−1(Ω)). Interestingly, no time derivatives appear in the auxiliary local problems, which are thus computed as in the steady state case. The role of the time variable is to parameterize the relative positions of the roughness shapes, and the homogenized coefficients result from averaging all such positions. To our knowledge, this is the first rigorous treatment of lubrication problems accounting for roughness on both surfaces.
Elasticity on a thin shell: Formal series solution
Authors: Faou Erwan
Published: December 2024

The three‐dimensional equations of elasticity are posed on a domain of $\mathbb{R}$ 3 defining a thin shell of thickness 2ε. The traction free conditions are imposed on the upper and lower faces together with the clamped boundary conditions on the lateral boundary. After a scaling in the transverse variable, the elasticity operator admits a power series expansion in ε with intrinsic coefficients with respect to the mean surface of the shell. This leads to define a formal series problem in ε associated with the three‐dimensional equations. The main result is the reduction of this problem to a formal series boundary value problem posed on the mean surface of the shell.
Semi‐classical limit of the scattering amplitude for trapping perturbations
Authors: Michel Laurent
Published: December 2024

We study the semi‐classical asymptotic as h→0 of the scattering amplitude f(θ,ω,λ,h) associated to a Schrödinger operator H(h)=−½h2Δ+V(x) for short‐range trapping perturbations. Our main result yields the leading term of the integral of f(θ,ω,λ,h) for θ,ω∈Sn−1 fixed and λ∈[λ0−ε,λ0+ε], ε>0, λ0>0, being a trapping energy level.
Partial regularity for a class of anisotropic variational integrals with convex hull property
Authors: Bildhauer M. , Fuchs M.
Published: December 2024

We consider integrands f : $\mathbb{R}$ nN→ $\mathbb{R}$ which are of lower (upper) growth rate s≥2 (q>s) and which satisfy an additional structural condition implying the convex hull property, i.e., if the boundary data of a minimizer u :Ω→ $\mathbb{R}$ N of the energy ∫Ωf(∇u) dx respect a closed convex set K⊂ $\mathbb{R}$ N, then so does u on the whole domain. We show partial C1,α‐regularity of bounded local minimizers if q<min {s+2/3,sn/(n−2)} and discuss cases in which the latter condition on the exponents can be improved. Moreover, we give examples of integrands which fit into our category and to which the results of Acerbi and Fusco [2] do not apply, in particular, we give some extensions to the subquadratic case.
Global in time Lp‐estimates for the instationary Stokes and Navier–Stokes flow through an aperture
Authors: Fröhlich Andreas
Published: December 2024

Using a characterisation of maximal Lp‐regularity by ℛ‐bounded operator families we prove global in time estimates in $L^{p}({\mathbb{R}}_{+};L^{q}(\varOmega))$ , 1<p,q<∞, for solutions of the instationary Stokes system in an aperture domain $\varOmega\subset{\mathbb{R}} ^{n}$ , n≥3, with $\curpartial\varOmega\in C^{1,1}.$ The results are applied to obtain new global in time estimates for weak solutions of the Navier–Stokes equations with nonvanishing flux through the aperture.
Some asymptotic analysis in steady‐state Euler–Poisson equations for potential flow
Authors: Peng Yue‐Jun
Published: December 2024

We study the zero‐electron‐mass limit, the zero‐relaxation‐time limit and the quasi‐neutral limit in steady‐state Euler–Poisson system for potential flow arising in mathematical modeling for plasmas and semiconductors. We show the existence and uniqueness of solutions when the electron‐mass is small enough. For the zero‐electron‐mass limit and the zero‐relaxation‐time limit, we prove the strong convergence of the sequence of solutions and give the corresponding error estimates. Whereas for the quasi‐neutral limit, we obtain the similar results only if the given data on the boundary are in equilibrium.
Symmetry‐breaking bifurcations of free boundary problems in three dimensions
Authors: Fontelos Marco A. , Friedman Avner
Published: December 2024

In this paper we consider free boundary problems for systems of partial differential equations. The system has solutions which are spherically symmetric with free boundary r=R, for any value of a parameter γ. We establish the existence of symmetry‐breaking bifurcation branches of solutions with free boundary of the form r=R+εF.
Asymptotic behaviour, with respect to the isothermal compressibility coefficient, for steady flows of weakly compressible viscoelastic fluids
Authors: Guillopé Colette , Mneimné Ali , Talhouk Raafat
Published: December 2024

In this paper, we study the behaviour, in terms of compressibility, of steady flows of weakly compressible viscoelastic fluids having a differential constitutive law. The models considered here are Jeffreys' and Maxwell's. In both cases, we establish the existence of an asymptotic expansion in the neighbourhood of the steady incompressible fluid flow, with respect to the vanishing isothermal compressibility coefficient.
A framework for asymptotic integration of differential systems
Authors: Elias Uri , Gingold Harry
Published: December 2024

A new method for asymptotic integration of linear systems of ordinary differential equations is proposed and studied. It is based on the introduction of a certain integral equation that pinpoints sufficient conditions for asymptotic integration. These conditions serve as a framework from which new and old theorems are derived. In particular the fundamental theorems of Levinson and Hartman–Wintner are shown to follow from one and the same scheme. The new theorems in asymptotic integration are shown to be best possible in a certain sense. Examples are given that are not amenable to other techniques.
Singular limit of a conserved Penrose–Fife model with special heat flux law and memory effects
Authors: Rocca Elisabetta , Schimperna Giulio
Published: December 2024

A phase‐field model of Penrose–Fife type for diffusive phase transitions with conserved order parameter is introduced. A Cauchy–Neumann problem is considered for the related parabolic system which couples a nonlinear Volterra integro‐differential equation for the temperature $\teta$ with a fourth order relation describing the evolution of the phase variable χ. The latter equation contains a relaxation parameter μ related to the speed of the transition process, which happens to be very small in the applications. Existence and uniqueness for this model as μ>0 have been recently proved by the first author. Here, the asymptotic behaviour of the model is studied as μ is let tend to zero. By a priori estimates and compactness arguments, the convergence of the solutions is shown. The approximating initial data have to be properly chosen. The problem obtained at the limit turns out to couple the original energy balance equation with an elliptic fourth order inclusion.