bluuebunny/crossref_metadata_2025 huggingface dataset:
Two Different Solution Techniques for an Optimal Control Problem with a Stochastic Switching Time
Authors: Buratto Alessandra , Grosset Luca , Muttoni Maddalena
Published: October 2023

In optimal control theory, strategic decision making requires the consideration of unforeseen disruptions that may arise within a predetermined time horizon. In this context, we introduce the concept of ”stochastic switching time” as a random moment in time at which a sudden, irreversible alteration takes place in the system’s dynamics or in the payoff function. To address optimal decision-making under such uncertain conditions, the literature presents two prominent methodologies: the ”backward” approach and the ”heterogeneous” approach. In this study, we offer an exposition and a comparative analysis of these two approaches. Finally, we present an illustrative example to show, in a detailed context, the advantages and disadvantages associated with these two solution strategies.
Reduction of Search Space for the Mean Partition Problem
Authors: Correa-Morris Jyrko
Published: October 2023

The contributions of this paper are threefold. First, it conducts a formal comparison of the primary approaches to consensus clustering, using the concepts of agreement and consent. Secondly, it presents theoretical evidence justifying the preference for mean-based methods, which rely on consent, over other agreement-based procedural methods like the q-rule, which are now mostly used as quality evaluators in practice. Thirdly, the paper computes the exact reduction achieved by criteria available in existing literature to assess the quality of mean-based consensus solutions and reduce the search space’s size. Finally, it compiles the regions where consensus functions associated with well-known dissimilarity measures, such as the Mirkin metric and Variation of Information, accumulate their consensus solutions.
Application of the Bilateral Hybrid Methods to Solving Initial -Value Problems for the Volterra Integro-Differential Equations
Authors: Ibrahimov Vagif , Mehdiyeva Galina , Imanova Mehriban , Juraev Davron Aslonqulovich
Published: October 2023

The many problems of natural sciences are reduced to solving integro-differential equations with variable boundaries. It is known that Vito Volterra, for the study of the memory of Earth, has constructed the integro-differential equations. As is known, there is a class of analytical and numerical methods for solving the Volterra integro-differential equation. Among them, the numerical methods are the most popular. For solving this equation Volterra himself used the quadrature methods. How known in solving the initial-value problem for the Volterra integro-differential equations, increases the volume of calculations, when moving from one point to another, which is the main disadvantage of the quadrature methods. Here the method is exempt from the specified shortcomings and has found the maximum value for the order of accuracy and also the necessary conditions imposed on the coefficients of the constructed methods. The results received here are the development of Dahlquist’s results. Using Dahlquist’s theory in solving initial-value problem for the Volterra integro-differential equation engaged the known scientists as P.Linz, J.R.Sobka, A.Feldstein, A.A.Makroglou, V.R.Ibrahimov, M.N.Imanova, O.S.Budnikova, M.V.Bulatova, I.G.Buova and ets. The scientists taking into account the direct connection between the initial value problem for both ODEs and the Volterra integrodifferential equations, the scientists tried to modify methods, that are used in solving ODEs and applied them to solve Integro-differential equations. Here, proved that some modifications of the methods, which are usually applied to solve initial-value problems for ODEs, can be adapted for solving the Volterra integro-differential equations. Here, for this aim, it is suggested to use a multistep method with the new properties. In this case, a question arises, how one can determine the validity of calculated values. For this purpose, it is proposed here to use bilateral methods. As is known for the calculation of the validity values of the solution of investigated problems, usually have used the predictor-corrector method or to use some bounders for the step-size. And to define the value of the boundaries, one can use the stability region using numerical methods. As was noted above, for this aim proposed to use bilateral methods. For the illustration advantage of bilateral methods is the use of very simple methods, which are called Euler’s explicit and implicit methods. In the construction of the bilateral methods it often becomes necessary to define the sign for some coefficients. By taking this into account, here have defined the sign for some coefficients.
Pharmacotherapy of glaucoma in terms of evidence-based medicine
Authors: Fedorov V. N. , Vdovichenko V. P. , Korsakov M. K. , Strakhov V. V. , Popova A. A. , Khokhlov A. I. , Suleymanov S. S.
Published: October 2023

Glaucoma is a disease associated with increased intraocular pressure (IOP). Of the pharmacological agents for treating glaucoma, there are drugs of the first (most effective and safe) and second-line treatment. First-line treatment includes prostaglandin analogs and beta-blockers. The currently used prostaglandin analogs (latanoprost, bimatoprost, tafluprost and travoprost) are PG F2α analogs that act through stimulation of FP receptors. They are distinguished by the optimal ratio of effectiveness and risk of side effects. They are convenient for the patient because for the therapeutic effect, it is enough to prescribe 1 time per day. As a result, it is rational to start the treatment of glaucoma with a drug in this group. In terms of pharmacoeconomics, the most affordable prostaglandin drug is latanoprost, which is generally as effective as other prostaglandin analogs. β-adrenergic blockers reduce the production of intraocular fluid, the formation of which is controlled by β1- and β2-adrenergic receptors. Therefore, non-selective β-blockers (timolol, levobunolol, metipranolol, and carteolol) have a pharmacodynamic advantage over selective β1-adrenergic antagonists (betaxolol). Conducted clinical studies of β-blockers have shown that given the cost, efficacy and safety, timolol was the most preferable treatment for glaucoma. In the presence of medical contraindications to the use of first-line drugs or to enhance their effectiveness, α2-agonists (apraclonidine and brimonidine), carbonic anhydrase inhibitors (usually local action: dorzolamide and brinzolamide), M-cholinomimetics (pilocarpine, carbachol and echothiopate), and also Rho-kinase inhibitors (ripasudil)
Analysis of test methods for frost resistance of concrete
Authors: Rozental N. K. , Chekhnii G. V.
Published: October 2023

Introduction. Frost resistance of concrete is one of the most challenging problems in concrete studies. Particularly important is the issue of methods of testing concrete for frost resistance. The existing standard methods require more detailed regulation of the test process in order to improve the reliability of the results.

Aim. To analyze the regulatory procedures of testing concrete for frost resistance with a view to make suggestions for improving standards.

Materials and methods. The analysis involved Russian and foreign standards and publications on methods of testing concrete for frost resistance.

Results. The authors analyzed the methods of testing concrete for frost resistance, included in Russian and some foreign standards. The quality of determining the frost resistance of concrete can be improved by controlling the temperature while freezing and thawing, in particular, by assessing the temperature in the concrete of the test samples. Controlling the air temperature in the freezer should be recognized as insufficient. The criteria for the state of concrete samples during and after cyclic freezing and thawing should be further verified. It is necessary to continue full-scale testing of concrete under severe climatic conditions, taking into account the real conditions of freezing and thawing of concrete in structures, and comparing the results of laboratory and full-scale tests, including satellite samples.

Conclusion. The analysis revealed the necessity to continue the research on clarifying the test methodology and criteria for assessing the state of concrete samples after freezing and thawing cycles. It is advisable to recreate devices for determining the dynamic modulus of elasticity of samples in freeze-thaw testing, to resume long-term full-scale tests of concrete under severe climatic conditions, and to develop a manual for creating frost-resistant concrete, taking into account the current level of concrete technology. Elimination of the existing drawbacks of the methodology will improve the reliability of test results.
Integral equations of the second kind in dynamic analysis of nonlinear systems with a finite number of degrees of freedom under arbitrary dynamic loading and material dependencies
Authors: Chernov Yu. T.
Published: October 2023

Introduction. Development of computational methods for nonlinear systems possesses a significant potential, considering that linear theory sometimes fails to accurately describe the properties of dynamic systems, and the linear approximation gives only a very rough idea of real processes for a number of cases.

Aim. Calculating linear systems and deriving the resulting equations for nonlinear systems involves impulse response and transfer functions of linear “generating” systems of differential equations. Such an approach in comparison with the traditional method of the so-called normal forms enables the calculation algorithm to be simplified considerably, avoiding several stages and presenting the solution by means of the normal mode method for linear systems directly with respect to the generalized coordinates.

Materials and methods. The paper presents a method and an algorithm developed for the calculation of nonlinear systems with a finite number of degrees of freedom under arbitrary dynamic loading and material nonlinearity. Systems of nonlinear differential equations were reduced to nonlinear integral equations of the second kind, considered as resulting equations. The solution was developed in time steps, the value of which, among other things, determines the accuracy of the solution and the nature of the computational algorithm.

Results. The paper presents main computational dependencies in a generalized form, convenient for numerical simulation. The author provides solutions for a nonlinear system with one degree of freedom and a cubic reactiondisplacement relation, as well as for a system with one and two degrees of freedom with a viscous damper. In both cases, the developed solution contains all properties of nonlinear systems, including the jump (transition) from the upper ascending branch to the lower, stable one, and the associated excitation of free oscillations.

Conclusions. According to the calculations, the occurrence of nonlinear effects in oscillating systems makes positive impact on their behavior, in resonant modes in particular.
Calculation of reinforced concrete structures: considerations on developing new theory (continued)
Authors: Nazarenko V. G. , Zvezdov A. I. , Larionov E. A.
Published: October 2023

Introduction. The authors develop the results of their previously published study in order to build up a nonlinear dissipative theory of concrete compressive strength. The present paper explores possibilities to improve the theory of calculation of concrete and reinforced concrete structures in the light of the accumulated knowledge.

Aim. To introduce an approach to developing a nonlinear dissipative theory of concrete compressive strength in the absence of regulatory documents for loading modes, using instead the standard classification of loads.

Results. The authors refer to the non-linear hereditary creep theory as the most accurate but time-consuming, and keeping its positive properties, reduce its equation of state to the equation of ageless concrete with its simplicity in application. In addition, the equation of state of concrete is solved in elementary functions and closed form in practically important cases.

The overwhelming majority of published scientific data on the behavior of creep curves in the area of reliable performance of reinforced concrete structures indicates smoothness and continuity of the curves. Considering that, the data obtained in short-term tests can be extended to the whole time interval, thus providing possibility for express analyses of the strain properties of concrete.

The study estimated the reversibility of creep strain and found out dissipativity of elastic strain. The authors established a nonlinear relation between strain and constant stress and introduced an approach to developing a nonlinear dissipative theory of concrete compressive strength in the absence of regulatory documents for loading modes, using instead the standard classification of loads.

Conclusions. The considered experimental data were recognized to provide qualitative information due to their apparent deficit. In order to obtain quantitative evaluation, the experiments should be reproduced a sufficient number of times.
Fen Bilimleri Dersinde Uygulanan Ters-Yüz Sınıf Modelinin Akademik Başarıya ve Üstbilişsel Farkındalığa Etkisi
Authors: ERTAŞ KARAASLAN Zeynep , KAPTAN Fitnat
Published: October 2023

Bu çalışmada, aktif öğrenme etkinlikleriyle “Madde ve Isı” ünitesi kapsamında yapılan ters yüz sınıf (TYS) modelinin öğrencilerin akademik başarılarına ve üstbilişsel farkındalıklarına etkisini incelemek ayrıca uygulamaya yönelik öğrencilerin görüşlerini belirlemek amaçlanmıştır. Araştırma 2021-2022 eğitim-öğretim yılı ikinci döneminde Ankara’daki bir devlet okulunda 6. sınıf olan 2 şube deney grubu (n=55), 2 şube kontrol grubu (n=50) olmak üzere, toplam 105 öğrenciyle yapılmıştır. Deney grubuna TYS modeli uygulanmış, kontrol grubunda mevcut öğretim programına göre dersler yürütülmüştür. Çalışmada karma yöntem desenlerinden açımlayıcı sıralı desen kullanılmıştır. Çalışmada nicel kısımda yarı deneysel deneme modeli olan ön test- son test kontrol gruplu model kullanılmış olup veri toplama aracı olarak “6. Sınıf Madde ve Isı Başarı Testi ve Çocuklar İçin Üstbilişsel Farkındalık Ölçeği” uygulanmıştır. Araştırmanın nitel boyutunda deney grubu öğrencilerinin TYS uygulamasına yönelik görüşlerini belirlemek amacıyla durum çalışmasından yararlanılmıştır. Çalışmanın nicel verileri SPSS-23 programı ile analiz edilmiştir. Nitel veriler ise betimsel analizle açıklanmıştır. Araştırmada elde edilen verilerden TYS modelinin öğrencilerin başarısını ve üstbilişsel farkındalıklarını deney grubu lehine arttırdığı sonucuna ulaşılmıştır. Ayrıca öğrencilerin TYS modeline ilişkin genel olarak olumlu görüş bildirdikleri ve TYS modelinin öğretimin etkililiği bakımından öğrencilere önemli katkılar sağladığı görülmüştür. Çalışmada TYS modelinin başarılı bir şekilde uygulanabilmesi için öğrencilerin teknolojik araç ve internet erişimine sahip olmaları ve öğrencilerin videoları izleyip ön öğrenmelerini yaparak sınıfa gelmeleri gerektiği önerilmiştir.
Etkileşimli Okuma Destekli Hayat Bilgisi Derslerinin İlkokul Öğrencilerinin Hayat Bilgisi Dersi ve Çevreye Yönelik Tutumlarına Etkisi
Authors: DURMAZ Mücahit , TOPÇAM Abdurrahman Baki , SÖNMEZ Muhammet , BAYSAL Zeliha Nurdan
Published: October 2023

Hayat bilgisi dersi, çocuklara yaşam içerisinden kesitlerle birlikte çeşitli bilgiler sunarak öğrencilerin sosyal ve toplumsal olayları anlamasına yardımcı olur. Bu dersin etkili bir şekilde öğretiminin yapılması, toplumun huzuru ve geleceği için önem arz etmektedir. Hayat bilgisi dersi genellikle ders kitabı kullanılarak işlense de bu derste kullanılabilecek başka materyaller de vardır. Resimli çocuk kitapları bu derslerde kullanılabilecek etkiye özgün materyallerden birisidir. Bu kitapların çocuklara okunması sürecinde etkileşimli okuma yönteminin kullanılması kitapların etkisini arttıracak ve öğretimi kolaylaştıracaktır. Bu araştırmada Hayat bilgisi dersinde etkileşimli okuma yöntemi kullanımının, ilkokul 3. Sınıf öğrencilerinin Hayat bilgisi dersi ve çevreye yönelik tutumlarına etkisi incelenmiştir. Araştırma nicel araştırma niteliği taşımakta olup yarı deneysel desen kullanılmıştır. Çalışmadaki katılımcılar kolay ulaşılabilir durum örneklemesi kullanılarak belirlenmiştir. Bu doğrultuda araştırmanın çalışma grubunu, Kocaeli İli Dilovası İlçesi’ne bağlı bir devlet okulunda öğrenim gören ve A, B, C şubelerinde yer alan 72 üçüncü sınıf öğrencisi oluşturmaktadır. Öncelikli olarak, çalışma grubunu oluşturan öğrencilere Çevre Tutum Ölçeği ve Hayat Bilgisi Dersi Tutum Ölçeği uygulanmıştır. Yapılan analiz neticesinde öğrencilerin çevreye yönelik tutumlarının ve hayat bilgisi dersine yönelik tutumlarının denk olduğu sonucuna ulaşılmıştır. Araştırma materyalleri için Hayat bilgisi dersi öğretim programındaki çevre farkındalığına yönelik 6 kazanım ve bu kazanımlara ilişkin 6 resimli çocuk kitabı belirlenmiştir. Belirlenen kitaplar, A şubesine etkileşimli okuma yöntemi ile B şubesine ise geleneksel okuma yöntemi ile uygulanmıştır. C şubesi ise ilgili öğrenme alanı ve kazanımları hayat bilgisi ders kitabı ile işlemiştir. Üç şubede devam eden ve toplamda beş hafta süren uygulama sürecinin ardından Çevre Tutum Ölçeği ve Hayat Bilgisi Dersi Tutum Ölçeği kullanılarak öğrencilerin tutumları tekrardan belirlenmiştir. Araştırma sonucunda etkileşimli okuma yöntemiyle işlenen hayat bilgisi derslerinin öğrencilerin hem çevreye hem de hayat bilgisi dersine yönelik tutumlarını geliştirdiği görülürken; geleneksel okuma ve ders kitabı kullanılan grupta anlamlı bir değişimin yaşanmadığı sonucuna ulaşılmıştır. Buradan yola çıkılarak etkileşimli okumanın hayat bilgisi derslerinde kullanılabilecek etkili bir yöntem olduğu söylenebilir.
The Influence of Teamwork and Leadership Style towards Employee Productivity in Retail Store
Authors: Jasmine Sephia , Hongdiyanto Charly
Published: October 2023

Employees are one of the most critical assets considered the driving force of operations in a company. Many companies can determine their success by paying attention to employee productivity. In the retail store, the employee’s productivity relates to how employees can carry out daily operational to-do list targets, punctuality, and initiative. Several factors, such as Leadership, teamwork, and environment, can influence employees' productivity in a company. The support of the organization is critical in creating a comfortable environment for the employees to work. Trust can be given through Leadership and a comfortable co-team. With the proper support from the externals, the employee can perform better on the work. This research was conducted to analyze the effect of teamwork and leadership style on employee productivity with Trust as a mediator. This research was conducted quantitatively, and the data will be analyzed using PLS. The subject includes employees of a store. The sampling technique used is saturated sampling. The results of this study indicate that Trust mediates the effect of leadership style on employee productivity. In addition to the mediation test, it can be concluded that Trust mediates the effect of teamwork on employee productivity.
Relationships between Service Quality, Brand Image, Customer Satisfaction, and Customer Loyalty of UC Makassar
Authors: Wijaya Justin , Putra Sinar Dharmayana
Published: October 2023

Economic development in recent years has been driven among others by the service industry. The fierce competitive situation has driven competing businesses to continually develop themselves to provide superior quality services and an excellent brand image to gain customer satisfaction and loyalty. This study aims to examine the relationships between service quality, brand image, customer satisfaction, and customer loyalty of UC Makassar. We collect research data from 68 students using a convenient sampling technique. We adopted the conceptual model from prior studies. PLS-SEM was conducted to test the relationships in the conceptual models. The outcomes indicate that customer satisfaction has a positive impact on customer loyalty. The findings also found that service quality positively affects brand image and customer satisfaction but not loyalty. Likewise, brand image has a positive effect on customer satisfaction but not on loyalty. The implications of this research, limitations, and directions for further research can be found below.
Strengthening Customer Loyalty through Customer Engagement, Customer Experience, and Service Innovation
Authors: Wijono Frederick Dewantara , Efrata Tommy Christian
Published: October 2023

The purpose of this study is to ascertain how customer engagement, customer experience, and service innovation impact customer loyalty. This study employs quantitative research techniques, and SmartPLS 3.0 is used for data processing. Non-probability sampling is used with purposeful sampling media, and questionnaires with a linear scale are used to collect the data. The study's target audience consists of Indonesian citizens who are at least 18 years old, have smartphones with the Gojek app installed, and have used Gojek services at least once. 243 participants made up the study's sample size. According to the study's findings, efficiency and user-friendliness of the customer experience have a significant impact on how engaged customers are with Gojek, while service innovation and the sensory component of the customer experience do not. Customer engagement and user-friendliness of the customer experience do not significantly affect customer loyalty for Gojek, but service innovation and the sensory and efficiency of the customer experience do. According to the study's findings, businesses should concentrate more on enhancing service innovation, sensory quality, and efficiency in order to increase customer loyalty.
ANALYSIS OF THE INFLUENCE OF FREE SHIPPING, CASH ON DELIVERY, AND LIVE STREAMING ON PURCHASE DECISIONS AT TIKTOK SHOP IN SURABAYA CITY
Authors: Utomo Priyo -
Published: October 2023

TikTok shop is an online shopping service feature of the TikTok application with the problem of late receipts being the focus of research. The objectives of this research was to find out what kind of impact cash-on-delivery transactions have and live streaming on purchasing decisions at the online store TikTok shop for people in the city of Surabaya partially and simultaneously. This type of research uses descriptive research methods with a quantitative approach with a population of 200 respondents in the Surabaya City community. With data collection techniques using questionnaires, data analysis in this study was multiple linear regression and data processing using SPSS software. The results of the research conducted, it shows that Cash on delivery (X1) has a positive and partially significant effect because t count > t table and sig <0, 05 with a result of 5.429 > 1.652 and a significance value of 0.000 <0.05. Live streaming (X2) has a positive and partially significant effect because t count > t table and sig <0.05 with the result 10.225 > 1.652 and the significance value is 0.000 <0.05. And simultaneously cash on delivery (X1), and live streaming (X2) has a positive and significant effect on purchasing decisions (Y) with the results f count> f table 101.259> 2.65 significant value of f test 0.000 <0.05
Código Latinoamericano y Caribeño contra el Cáncer. Sepa cómo ayudar a prevenir el cáncer en usted y su familia
Authors:   IARC
Published: October 2023

La Agencia Internacional de Investigación sobre el Cáncer de la Organización Mundial de la Salud y la Organización Panamericana de la Salud convocaron a un grupo de especialistas y representantes de la sociedad civil de América Latina y el Caribe para que formularan una serie de medidas de prevención del cáncer basadas en la evidencia científica sólida más reciente y adaptadas a escenarios comunes en la subregión. A raíz de dicha iniciativa, este código presenta 17 acciones para ayudar a prevenir el cáncer, así como recomendaciones de políticas públicas dirigidas a garantizar su aplicación eficaz.
Ausentismo Laboral de Origen Médico en los Conductores de la Empresa Cootrasar de la Ciudad de Cúcuta
Authors: Pabón Trujillo Herminio
Published: October 2023

Introducción. A lo largo de este proyecto analizaremos la problemática que viene presentando la empresa COOTRASAR de Cúcuta con los conductores asignados para cubrir rutas intermunicipales, basados en referentes tanto internacionales como nacionales; podemos observar que este problema no solo aqueja al trabajador, si no que a su vez también afecta la operación de la empresa; para ellos emplearemos una serie de recursos que nos llevara a determinar que produce el ausentismo por enfermedad laboral. Objetivo. Determinar las causas que generen ausentismos laborales de origen médico en los conductores de la empresa COOTRASAR de la ciudad de Cúcuta. Metodología. Para realizar esta investigación se utiliza la técnica de observación y recopilación de datos y se realizará un estudio de enfoque mixto con base la información recopilada en el Software INCHECK de la empresa COOTRASAR de Cúcuta. Resultados. Se logra evidenciar que el ausentismo laboral se incrementa en conductores que llevan más de 15 años ejerciendo esta labor, y esto es esto es causado por una exposición prolongada a los elementos y al estado de las vías por donde transitan. Los ausentismos en un 60% son asociados a desordenes musculo esqueléticos, mientras un 30% se debe a patologías asociadas trastornos psicosomáticos.
Déficit Combinado de Proteína C y S de la Coagulación en Paciente Joven como Causa de Enfermedad Cerebrovascular Isquémica, a Propósito de 1 caso Clínico
Authors: Theran león Juan Sebastián , Dulcey Sarmiento Luis Andrés , Parra Rincón Camila Andrea , Lobo Paternina Maria Camila , Estévez Silva Tatiana , Jimenez Casadiego Daniella Alexandra , Robles Machuca Willian Javier , Hernández Jaramillo Laura Lisseth
Published: October 2023

La proteína C (PC) es un precursor de la serina proteasa, proteína C activada (PCA). Su activación proteolítica por trombina ocurre en la superficie del endotelio células e involucra trombomodulina y receptor de PC endotelial (RPCE). La proteína S (PS) también ejerce un efecto inhibidor directo independiente de PCA sobre el complejo de protrombinasa al unirse a FXa y FVa, y por tanto produce en la activación alterada de la protrombina. Además, la PS estimula el inhibidor de la vía del factor tisular. (IFT) en la inactivación de FXa. Los pacientes con deficiencia hereditaria de PC/PS tienen un alto riesgo de recurrencia de tromboembolismo venoso (TEV). Un estudio retrospectivo en una gran cohorte de familias ha demostrado que la incidencia anual de la primera recurrencia después de un primer episodio de TEV fueron del 6,0% (IC del 95%, 3,9–8,7) en pacientes con deficiencia de PC y del 8,4% (IC del 95%, 5,8–11,7) en pacientes con deficiencia de PS. Presentamos el caso de un paciente masculino joven quien desarrollo un evento cerebrovascular isquémico. El rankin previo al evento era de 1 punto. No presentaba antecedentes de importancia. Niega ingesta de medicaciones o condiciones cardiometabolicas. Al examen físico presento una monoparesia crural derecha de 2/5. El estudio de tomografía de cráneo simple mostro una zona isquémica en el territorio del circuito anterior izquierdo. No se identificaron alteraciones arrítmicas, lesión cardiaca estructural, no imágenes en el estudio de angiotomografia de cráneo. Se ordenaron pruebas de trombofilia las cuales identificaron déficit combinado de proteína C y S. El riesgo de un evento trombotico arterial expresado como evento cerebrovascular es desconocida ya que es un evento realmente atípico. El presente caso es anecdótico dada la escasa frecuencia de este tipo de eventos.
Üniversite Öğrencilerinin Boş Zaman Tutumlarının İncelenmesi
Authors: İSLAMOĞLU İzzet , KAPLAN Abdurrahim
Published: October 2023

Bu çalışmada, Ondokuz Mayıs üniversitesi öğrencilerinin boş zaman tutumlarının incelemesi amaçlanmıştır. Bu çalışma Spor Bilimleri, Sağlık Bilimleri, İktisadi ve İdari Bilimler ve İlahiyat Fakültesi’nde öğrenim gören ve çalışmaya gönüllü olarak katılan 400 öğrenciden oluşmaktadır. Öğrencilerin boş zaman tutumları belirlemek amacıyla Ragheb ve Beard (1982)’ın geliştirmiş olduğu Akgül ve Gürbüz (2011) Türkçe uyarladığı “Boş Zaman Tutum Ölçeği” kullanıldı. Üniversite öğrencilerinin bilgisayar oyunu oynama ve cinsiyet durumuna göre boş zaman tutumları duyuşsal, bilişsel ve davranışsal alt boyutlarında anlamlı farklılık bulunmadı (p>0,05). Üniversite öğrencilerinin gelir durumuna göre boş zaman tutum düzeyleri duyuşsal ve bilişsel alt boyutlarda anlamlı farklılık tespit edilmedi (p>0.05). Ancak, davranışsal alt boyutunda anlamlı farklılık bulundu (p
Active Galactic Nucleus Quenching in Simulated Dwarf Galaxies
Authors: Sharma Ray S. , Brooks Alyson M. , Tremmel Michael , Bellovary Jillian , Quinn Thomas R.
Published: October 2023

We examine the quenching characteristics of 328 isolated dwarf galaxies

10

8

<

M

star

/

M

⊙

<

10

10

within the Romulus25 cosmological hydrodynamic simulation. Using mock-observation methods, we identify isolated dwarf galaxies with quenched star formation and make direct comparisons to the quenched fraction in the NASA Sloan Atlas (NSA). Similar to other cosmological simulations, we find a population of quenched, isolated dwarf galaxies below M
star < 109
M
⊙ not detected within the NSA. We find that the presence of massive black holes (MBHs) in Romulus25 is largely responsible for the quenched, isolated dwarfs, while isolated dwarfs without an MBH are consistent with quiescent fractions observed in the field. Quenching occurs between z = 0.5–1, during which the available supply of star-forming gas is heated or evacuated by MBH feedback. Mergers or interactions seem to play little to no role in triggering the MBH feedback. At low stellar masses, M
star ≲ 109.3
M
⊙, quenching proceeds across several Gyr as the MBH slowly heats up gas in the central regions. At higher stellar masses, M
star ≳ 109.3
M
⊙, quenching occurs rapidly within 1 Gyr, with the MBH evacuating gas from the central few kpc of the galaxy and driving it to the outskirts of the halo. Our results indicate the possibility of substantial star formation suppression via MBH feedback within dwarf galaxies in the field. On the other hand, the apparent overquenching of dwarf galaxies due to MBH suggests that higher-resolution and/or better modeling is required for MBHs in dwarfs, and quenched fractions offer the opportunity to constrain current models.
NLTE Analysis of Y i and Y ii in the Atmospheres of FGK Stars
Authors: Alexeeva Sofya , Wang Yu , Zhao Gang , Wang Feng , Wu Yong , Wang Jianguo , Yan Hongliang , Shi Jianrong
Published: October 2023

The nonlocal thermodynamical equilibrium (NLTE) line formation of Y i and Y ii is considered in 1D LTE model atmospheres of FGK-type stars. The model atom was constructed with the most up-to-date atomic data, including quantum cross sections and rate coefficients for transitions in inelastic collisions of Y i and Y ii with hydrogen atoms. For seven reference stars, we obtained an agreement between NLTE abundances inferred from the two ionization stages, while the difference in LTE abundance (Y i and Y ii) can reach up to −0.31 dex. In the atmospheres of FGK-type stars, for both Y i and Y ii lines, the NLTE abundance corrections are positive. In solar metallicity stars, the NLTE abundance corrections for Y ii lines do not exceed 0.12 dex, while in atmospheres of metal-poor stars, they do not exceed 0.21 dex. For Y i lines, the NLTE abundance corrections can reach up to ∼0.5 dex. We determined the yttrium NLTE abundances for a sample of 65 F and G dwarfs and subgiants in the −2.62 ≤ [Fe/H] ≤ +0.24 metallicity range, using high-resolution spectra. For stars with [Fe/H] ≤ −1.5, [Y/Fe] versus [Fe/H] diagram reveals a positive trend with an average value of [Y/Fe] ≃ 0. For metal-poor stars, among Sr, Y, and Zr, the arrangement [Sr/Fe] < [Y/Fe] < [Zr/Fe] remains consistent. The current study is useful for Galactic chemical evolution research. The model atom will be applied for NLTE yttrium abundance determination in very metal-poor stars studied with LAMOST and Subaru.
Confirmation of an Anomalously Low Dark Matter Content for the Galaxy NGC 1052-DF4 from Deep, High-resolution Continuum Spectroscopy
Authors: Shen Zili , van Dokkum Pieter , Danieli Shany
Published: October 2023

NGC 1052-DF4 was found to be the second “galaxy lacking dark matter” in the NGC 1052 group, based on its velocity dispersion of

σ

gc

=

4.2

−
2.2

+
4.4

km s−1 as measured from the radial velocities of seven of its globular clusters. Here we verify this result by measuring the stellar velocity dispersion of the galaxy. We observed the diffuse stellar light in NGC 1052-DF4 with the Keck Cosmic Web Imager in its highest-resolution mode, with

σ

instr

≈
7

km s−1. With a total science + sky exposure time of 34 hr, the resulting spectrum is exceptional in both its spectral resolution and its signal-to-noise ratio of 23 Å−1. We find a stellar velocity dispersion of

σ

stars

=

8.0

−
1.9

+
2.3

km s−1, consistent with the previous measurement from the globular clusters. Combining both measurements gives a fiducial dispersion of

σ

f

=

6.3

−
1.6

+
2.5

km s−1. The implied dynamical mass within the half-light radius is

8

−
4

+
6

×

10
7

M
⊙

. The expected velocity dispersion of NGC 1052-DF4 from the stellar mass alone is 7 ± 1 km s−1, and for a Navarro–Frenk–White (NFW) halo that follows the stellar mass–halo mass relation and the halo mass–concentration relation, the expectation is ∼30 km s−1. The low velocity dispersion rules out a normal NFW dark matter halo, and we confirm that NGC 1052-DF4 is one of at least two galaxies in the NGC 1052 group that have an anomalously low dark matter content. While any viable model for their formation should explain the properties of both galaxies, we note that NGC 1052-DF4 now poses the largest challenge, as it has the most stringent constraints on its dynamical mass.
A SPectroscopic Survey of Biased Halos in the Reionization Era (ASPIRE): JWST Discovers an Overdensity around a Metal Absorption-selected Galaxy at z ∼ 5.5
Authors: Wu Yunjing , Wang Feige , Cai Zheng , Fan Xiaohui , Finlator Kristian , Yang Jinyi , Hennawi Joseph F. , Sun Fengwu , Champagne Jaclyn B. , Lin Xiaojing , Li Zihao , Chen Zuyi , Bañados Eduardo , Becker George D. , Bosman Sarah E. I. , Bruzual Gustavo , Charlot Stephane , Chen Hsiao-Wen , Chevallard Jacopo , Eilers Anna-Christina , Farina Emanuele Paolo , Jin Xiangyu , Jun Hyunsung D. , Kakiichi Koki , Li Mingyu , Liu Weizhe , Pudoka Maria A. , Tee Wei Leong , Xie Zhang-Liang , Zou Siwei
Published: October 2023

The launch of JWST opens a new window for studying the connection between metal-line absorbers and galaxies at the end of the Epoch of Reionization. Previous studies have detected absorber–galaxy pairs in limited quantities through ground-based observations. To enhance our understanding of the relationship between absorbers and their host galaxies at z > 5, we utilized the NIRCam wide-field slitless spectroscopy to search for absorber-associated galaxies by detecting their rest-frame optical emission lines (e.g., [O III] + Hβ). We report the discovery of a Mg ii-associated galaxy at z = 5.428 using data from the JWST ASPIRE program. The Mg ii absorber is detected on the spectrum of quasar J0305–3150 with a rest-frame equivalent width of 0.74 Å. The associated galaxy has an [O III] luminosity of 1042.5 erg s−1 with an impact parameter of 24.9 pkpc. The joint Hubble Space Telescope–JWST spectral energy distribution (SED) implies a stellar mass and star formation rate of M
* ≈ 108.8
M
⊙, star-formation rate  ≈ 10 M
⊙ yr−1. Its [O III] equivalent width and stellar mass are typical of [O III] emitters at this redshift. Furthermore, connecting the outflow starting time to the SED-derived stellar age, the outflow velocity of this galaxy is ∼300 km s−1, consistent with theoretical expectations. We identified six additional [O III] emitters with impact parameters of up to ∼300 pkpc at similar redshifts (∣dv∣ < 1000 km s−1). The observed number is consistent with that in cosmological simulations. This pilot study suggests that systematically investigating the absorber–galaxy connection within the ASPIRE program will provide insights into the metal-enrichment history in the early Universe.
Unveiling the Nature of Galactic TeV Sources with IceCube Results
Authors: Vecchiotti V. , Villante F. L. , Pagliaroli G.
Published: October 2023

IceCube collaboration reported the first high-significance observation of the neutrino emission from the Galactic disk. The observed signal can be due to diffuse emission produced by cosmic rays interacting with interstellar gas but can also arise from a population of sources. In this paper, we evaluate both the diffuse and source contribution by taking advantage of gamma-ray observations and/or theoretical considerations. By comparing our expectations with IceCube measurements, we constrain the fraction of Galactic TeV gamma-ray sources (resolved and unresolved) with hadronic nature. In order to be compatible with the IceCube results, this fraction should be small, or the source proton energy cutoff should be well below the cosmic-ray proton knee. In particular, for a cutoff energy equal to 500 TeV, the fraction of hadronic sources should be less than ∼40% corresponding to a cumulative source flux Φ
ν,s ≤ 2.6 × 10−10 cm−2 s−1 integrated in the 1–100 TeV energy range. This fraction reduces to ∼20% for energy cutoff reaching the cosmic-ray proton knee around 5 PeV.
An Extremely Massive White Dwarf Escaped from the Hyades Star Cluster
Authors: Miller David R. , Caiazzo Ilaria , Heyl Jeremy , Richer Harvey B. , El-Badry Kareem , Rodriguez Antonio C. , Vanderbosch Zachary P. , van Roestel Jan
Published: October 2023

We searched the Gaia DR3 database for ultramassive white dwarfs with kinematics consistent with having escaped the nearby Hyades open cluster, identifying three such candidates. Two of these candidates have masses estimated from Gaia photometry of approximately 1.1 solar masses; their status as products of single-stellar evolution that have escaped the cluster was deemed too questionable for immediate follow-up analysis. The remaining candidate has an expected mass >1.3 solar masses, significantly reducing the probability of it being an interloper. Analysis of follow-up Gemini GMOS spectroscopy for this source reveals a nonmagnetized hydrogen atmosphere white dwarf with a mass and age consistent with having formed from a single star. Assuming a single-stellar-evolution formation channel, we estimate a 97.8% chance that the candidate is a true escapee from the Hyades. With a determined mass of 1.317 solar masses, this is potentially the most massive known single-evolution white dwarf and is by far the most massive with a strong association with an open cluster.
Spider fauna (Arachnida, Araneae) in Mordovia State Nature Reserve and National Park “Smolny” (Russia)
Authors: Esyunin Sergei , Agafonova Oksana , Ruchin Alexander , Semishin Gennadiy , Esin Mikhail , Artaev Oleg
Published: October 2023

Ecosystems in protected areas are richer in animal and plant species diversity ("biodiversity hotspots") due to more stringent conservation conditions. Of particular importance is scientific research and monitoring of this diversity in such areas. The aim of this study is to describe a set of data on Araneae occurrence in two protected areas: Mordovia State Nature Reserve and National Park "Smolny".

About 29,000 individuals are identified to the species level. In total, 342 species were recorded for both PAs. The greatest species diversity was recorded in the families Linyphiidae (109 species; 32%), Lycosidae (38 species; 11%) Gnaphosidae (28 species; 8%), Araneidae (25 species; 7%), Salticidae (24 species; 7%), Thomisidae (23 species; 7%) and Theridiidae (22 species; 6% from total species diversity). The five species most abundant in the lower stratum (litter and moss layer) of biocenoses were Diplocephalus picinus, Microneta viaria, Tenuiphantes tenebricola, Diplostyla concolor and Abacoproeces saltuum and the five species most abundant in the vegetative stratum (herb, shrub and tree stems and canopy) were Linyphia triangularis, Enoplognatha ovata, Evarcha falcata, Misumena vatia and Evarcha arcuata. The dataset contains information on the occurrence of seven rare species (Centromerus nurgush, Centromerus persimilis, Diplocephalus dentatus, Entelecara flavipes, Metapanamomops kaestneri, Pelecopsis radicicola and Porrhomma microcavense), three species (Agalenatea redii, Neoscona adianta, Thanatus oblongiusculus) that entered here from the steppe zone and two synanthropic species (Steatoda castanea, Tegenaria domestica).
Evaluation of neutronic performance for the VVER-1000 reactor core with regenerated uranium-plutonium fuel
Authors: Semishin Viktor V.
Published: October 2023

The possibility has been considered for the VVER-1000 reactor fuel loading to be formed based on regenerated fuel with the use of the spent fuel accumulated in reactors of the same type. A study was undertaken to investigate the change in the isotopic composition of the plutonium discharged from a thermal reactor in the course of its multiple reprocessing and recycle in a thermal neutron reactor. To obtain an equilibrium isotopic composition of the reactor-grade plutonium, 3D neutronic calculations were performed for the stationary fuel cycles of a VVER-1000 serial reactor with conventional oxide fuel and oxide fuel based on regenerated uranium and based on an undivided mixture of uranium and plutonium oxides from SNF. The neutronic performance of reactor cores was compared for the above mentioned fuel types in the course of the fuel company, including the following: in-core radial power density shaping, values of reactivity coefficients for various thermal parameters, reactivity control system efficiency, etc.
Usage des liaisons variables dans deux corpus de lecture
Authors: Dugua Céline
Published: October 2023

Notre travail porte sur l’usage des liaisons variables en lecture et, plus spécifiquement, dans la lecture d’ouvrages destinés aux enfants, à partir de deux corpus : un module du corpus eslo , portant sur des lectures partagées entre adultes et enfants (30 histoires lues), et la lecture d’un même conte ( Pierre et le loup ) par 79 lecteurs comparée à celle réalisée par B. Giraudeau dans un livre audio (Pustka 2017). La complémentarité de ces deux corpus permet de mieux cerner l’influence de l’accès aux formes graphiques des mots sur la réalisation des liaisons et également de rendre compte des différents facteurs qui font varier cet usage.
Le rôle de l’usage dans l’acquisition de la liaison : production et perception d’élèves franco-germanophones bilingues
Authors: Heiszenberger Elisabeth
Published: October 2023

L’objectif de la présente étude est de tester l’influence de la fréquence sur l’acquisition de la liaison dans une nouvelle population, soit chez 49 enfants et adolescents bilingues franco-germanophones différant par leur temps d’exposition au français. L’étude montre que, même si les enfants bilingues présentent les mêmes trajectoires d’acquisition que les enfants monolingues, les phases développementales diffèrent de celles observées chez ces derniers. Toutefois, le développement semble être nettement hétérogène : plus la compétence linguistique est élevée, plus le développement de la liaison est avancé. La présente étude fournit donc de nouveaux arguments pour les approches basées sur l’usage mais souligne la présence d’autres facteurs qui entrent en jeu, à savoir la scolarisation ou l’enseignement explicite de la liaison.
Liaison et impression : phonologie populaire à travers les intuitions de deux groupes d’adolescents francophones
Authors: Akissi Boutin Béatrice , De Flaviis Giulia , Floquet Oreste
Published: October 2023

L’objectif de ce travail est de commenter les résultats d’un test d’acceptabilité administré à une population de jeunes collégiens. Poursuivant un travail déjà entamé sur la perception de la liaison et les représentations subjectives (Laks & Floquet 2017 ; Celata, De Flaviis & Floquet 2020 ; De Flaviis 2021), nous nous intéressons aussi bien à la compétence épiphonologique qu’à la conscience métaphonologique de deux groupes d’adolescents de Toulouse et Menton. Nos premiers résultats vont dans le sens d’une divergence entre ce que le chercheur trouve dans un corpus et ce que l’auditeur naïf perçoit de son côté surtout en ce qui concerne le statut de la liaison.
Indexicalité et interprétation du monde social : une analyse socio-pragmatique de la liaison variable
Authors: Martin Alexander , Abbou Julie , Burnett Heather
Published: October 2023

Des travaux antérieurs ont souligné un lien fort entre liaison variable et écrit mais n’ont pas développé une analyse explicite de ce lien. Dans cet article, nous proposons un cadre théorique basé sur la sociologie pragmatique (Boltanski & Thévenot 1991) qui permet de rendre compte des sens sociaux qui émergent lors de la réalisation de la liaison variable en situation. En esquissant un champ indexical de l’écrit, nous proposons que plusieurs ensembles de sens soient potentiellement en jeu lors de la réalisation d’une liaison variable. Grâce à un test expérimental basé sur la Matched Guise Technique , où face à des scénarios décrivant des échanges sociaux, les participants devaient indiquer leur préférence pour la liaison réalisée ou non. Nous montrons que la liaison variable prend sens notamment dans le « monde industriel » où le professionnalisme est valorisé et peut évoquer la préparation derrière un texte écrit.
Extent and spatial distribution of karst in Slovenia
Authors: Gostinčar Petra , Stepišnik Uroš
Published: October 2023

This study investigates the spatial distribution of karst in Slovenia using advanced GIS technologies and accurate lithology, hydrology, and digital relief data. Previous approaches led to an incomplete understanding of karst distribution, as they focused on carbonate lithologies and surface features. Our integrated two-step identification method, involving GIS layer overlays and manual review of lithology data, resulted in a comprehensive digital spatial database. We found that karst covers 49.7% of Slovenia's total area, with a diverse range of associated lithologies. This research has important implications for managing and protecting karst aquifers, forest planning, agricultural subsidies, and glacial geomorphology studies, and enables further processing and enhancement by the karst research community.
Un retrato de Ptolomeo III Evergetes, procedente de colonia Patricia (Córdoba, España)
Authors: Loza Azuaga María Luisa , Beltrán Fortes José
Published: October 2023

Se estudia un herma de un personaje masculino, adquirido por el Museo Arqueológico y Etnológico de Córdoba en la década de 1970. Procede de un descubrimiento ocasional en la calle Ángel de Saavedra, en los Altos de Santa Ana. Ha sido interpretado como monarca helenístico o atleta, de manera genérica, así como representación del dios Hermes. En este artículo lo identificamos como retrato idealizado del monarca lágida Ptolomeo III Evergetes, tanto por sus rasgos fisonómicos, como especialmente por el atributo que debió llevar en el centro de la diadema, una hoja o flor de loto, simbolizando su vinculación con Egipto, aunque hoy no se conserva y solo presenta el rebaje y orificio donde se ajustaría. Sería elaborado en un taller oriental (Ática) en época de Augusto.
Contemporary French prisons
Authors: Lancelevée Camille , Scheer David
Published: October 2023

Although it is constantly under fire, prison remains the main form of punishment in France’s justice system. How are we to explain the longevity of this controversial institution? How can the reality of prison be described? What is a prison sentence in today’s France? This paper reconsiders prison by focusing on its paradoxes. The authors question the place of prison in society, reframe the debates on prison and shed light on everyday life in prison in France. Ultimately, they call for contextualizing the analysis of contemporary prison within a broader reflection on our society.