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Publikacije (45031)

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Demir Bektić, Asad Khan, Lukas Körber

The rising popularity of index‐replicating Exchange Traded Funds (ETFs) reflects the broader shift toward passive investing. However, the DAX 40 index incorporates an active component through inclusions and deletions, which affect investor returns. While the short‐term “index inclusion effect” around announcement and inclusion dates is well‐documented, we focus on long‐term post‐rebalancing dynamics. We show that newly included stocks between 2010 and 2023 outperformed the DAX 40 by an average of 33.2% during the 12 months before inclusion but underperformed an average of 36.1% over the subsequent 24 months. This mean reversion can be leveraged via a market‐neutral strategy that shorts newly included stocks on the inclusion date and pairs this with a long DAX ETF position. Maintaining the short for 18 months generates a statistically significant alpha relative to a Fama–French six‐factor asset pricing model, even after accounting for transaction costs. Our study reveals a hidden performance drag in the DAX 40 index, with important implications for passive investors in the index.

Calli Tzani, Maria Ioannou, J. Synnott, T. Williams, Vasiliki Artinopoulou, Lamprini Ntountoumi, Arta Dodaj, Kristina Sesar et al.

Purpose This study investigates the effects of online dating platforms on users’ wellbeing and the success rates of forming relationships through these services. Given the ongoing debate surrounding the impact of online dating, this study aims to provide empirical insights into its outcomes. Design/methodology/approach This study used a sample of 618 participants from four countries (Croatia, Greece, Italy and Malta) to gain a comprehensive perspective on online dating experiences. Data was collected to assess both the impact on wellbeing and the likelihood of forming relationships through these platforms. Findings The results indicated that using online dating platforms did not significantly affect users’ wellbeing, either positively or negatively. In addition, most users were unable to establish committed or casual relationships through these platforms, suggesting limited success in achieving romantic or personal connections. Originality/value These findings highlight potential inefficiencies in online dating platforms in facilitating meaningful relationships or personal benefits for users. The study contributes to ongoing discussions about the effectiveness of such services and provides a foundation for future research on their impact and potential improvements.

Esra Aycan Beyazit, Jeroen Famaey, Nina Slamnik-Kriještorac, Johann M. Márquez-Barja, Miguel Camelo Botero

This letter proposes a multi-stream selection framework for \ac{CF-MIMO} networks. Partially coherent transmission has been considered by clustering \acp{AP} into phase-aligned clusters to address the challenges of phase misalignment and inter-cluster interference. A novel stream selection algorithm is developed to dynamically allocate multiple streams to each multi-antenna \ac{UE}, ensuring that the system optimizes the sum rate while minimizing inter-cluster and inter-stream interference. Numerical results validate the effectiveness of the proposed method in enhancing spectral efficiency and fairness in distributed \ac{CF-MIMO} networks.

Nermina Klapuh-Bukvić, Zehra Kurtanović, Damir Šeper

Background Differentiation of leukocytes is one of the key diagnostic procedures in clinical medicine, and correct identification of them in a blood smear is of essential importance. Light microscopy is the reference method for leukocyte differentiation; however, it is time-consuming and must be performed by a highly qualified specialist. For this reason, automatic analysers capable of precise and accurate differentiation of blood cells in the examined sample are increasingly present in haematology laboratories. This paper aims to evaluate the performance of the Sysmex XN-3100 analyser, manufactured by SYSMEX CORPORATION, Kobe, Japan., with a focus on the advantages and disadvantages of its digital microscopy in the differentiation of leukocytes and give brief guidelines on the possibilities and limitations of everyday work on the basis of the obtained results. Methods Digital optical microscopy on 253 samples was performed with primary data (preclassification) collected after the completion of the autoanalysis. Before validating the obtained results, the data were reviewed by a medical biochemistry specialist who confirmed or corrected them. This generated secondary data (reclassification). The two groups of data were statistically analysed using Passing-Bablok regression analysis, Bland-Altman analysis and Spearman correlation. Results The obtained results showed strong correlations between the primary and secondary analysis in all cells (highest in lymphocyte group (r=0.986), lowest in eosinophil group (r=0.870)) except immature granulocytes and blasts (significant deviation from linearity, p<0.01). Conclusions The haematology analyser Sysmex XN-3100 shows high performance in leukocyte analysis and differentiation using digital microscopy, but samples containing blasts and immature granulocytes must additionally be analysed by light microscopy.

Berina Hasanefendic, Aleksandra Pašić, Lajla Halilović, Ahmed Velić, Jasna Topalović-Ćetković, Amir Fazlagić

In our letter, we presented the challenges within medical biochemistry in a tertiary hospital in a measles outbreak. The letter somewhat shows the current situation in the first part. In the remaining part, the challenges in the work of the medical biochemical laboratory are listed and the significance of the most common biochemical and hematological analyzes for these patients is explained. This letter is an important clinical-epidemiological overview of the current situation that arose as a result of the measles outbreak.

Milica D. Pavlovic, M. Lagisz, N. B. Videira, Julia M L Menon, G. Vist, Elma Omeragić, Rebecca L. Morgan, Sebastian Hoffmann et al.

R. Galbusera, Matthias Weigel, Erik Bahn, S. Schaedelin, A. Cagol, Po-Jui Lu, M. Barakovic, L. Melie-García et al.

Remyelination of cortical lesions in people with multiple sclerosis (pwMS) has been shown to be extensive. In this work, we aimed to assess whether postmortem quantitative MRI (qMRI) can help detect those areas. We imaged six fixed whole brains of deceased pwMS by 3T‐MRI using magnetization transfer ratio (MTR, 570 μm isotropic), myelin water fraction (MWF, 1000 μm isotropic), quantitative T1 (qT1, 670 μm isotropic), quantitative susceptibility mapping (QSM, 330 μm isotropic) and radial diffusivity (RD, 1300 or 1400 μm isotropic) maps. Immunohistochemistry for myelin proteins was performed in 129 tissue blocks including the cortex and enabled the detection of cortical demyelination (DM), cortical remyelination (RM), and normal‐appearing cortex (NAC). We identified 25 DM, 25 RM, and for each of these areas, a corresponding NAC near the lesion. Wilcoxon paired tests showed that: (a) qT1 and RD were higher and QSM lower in DM versus NAC (all p < 0.001), whereas RD was higher and QSM lower in RM versus NAC (p = 0.048 and p < 0.01 respectively); (b) mean qT1 in RM did not differ from mean qT1 in NAC (p = 0.074); (c) MWF and MTR were not different between DM and RM. We compared the delta between DM versus NAC (∆DM) and the delta between RM versus NAC (∆RM) using a Mann–Whitney test, in which RM showed a partial recovery of qT1 only (∆qT1 DM > ∆qT1 RM, p = 0.045). Mixed‐effect models confirmed the findings obtained using univariate analyses. qT1 and QSM, but not RD, correlated with MBP intensity (r = −0.28, p < 0.01 and r = 0.29, p < 0.01 respectively). A Bonferroni correction was performed for multiple testing. Our data show that qT1 is altered in demyelinated but not in remyelinated cortical areas, while QSM and RD are affected by any cortical abnormalities. Accordingly, qT1 might be considered a potential imaging biomarker of cortical RM.

The Trends in International Mathematics and Science Study (TIMSS) is a large-scale international assessment that measures students’ achievement in mathematics and science at the fourth and eighth-grade levels. Coordinated by the International Association for the Evaluation of Educational Achievement (IEA), TIMSS is conducted every four years. The 2023 assessment represented the eighth cycle of TIMSS, collecting data from 64 participating countries. This exploratory study examines the influence of several key factors—gender, home learning resources, experiences of bullying, disruptive classroom behavior, and students’ sense of school belonging—on fourth-grade mathematics achievement in Bosnia and Herzegovina. The research sample included 2,712 students (mean age: 10.2 years; SD = 0.4; 1,388 girls and 1,324 boys). Results showed that home learning resources were the most important predictor of mathematics achievement, emphasizing the essential role that home educational conditions play in student academic outcomes. The observed difference between boys and girls in mathematics scores was minimal. Both bullying and disruptive behavior were found to have a statistically significant negative impact on mathematics performance, whereas the effect of students’ sense of school belonging did not reach statistical significance. Home learning resources proved to be the most decisive variable in forecasting mathematics achievement among fourth-grade students in Bosnia and Herzegovina, reinforcing the value of home-based educational support in fostering academic progress. These results suggest the necessity for educational policies and interventions that ensure fair access to learning resources within the home environment. The paper concludes with a discussion of the implications of these findings and outlines potential avenues for future research and educational practice.

Irzada Taljić, Lejla Biber, Almir Toroman, Amel Mekić

Athlete nutrition is an important aspect of training itself. Athletes must take sufficient amounts of all nutrients (carbohydrates, fats, and proteins) on a daily basis, as well as vita-mins and minerals that often have a crucial impact on the quality of training. Daily calories vary depending on the intensity of training, gender, and body weight of the individual. Satis-faction with daily caloric needs is crucial in maintaining constant body weight, achieving fast recovery after activity, and growth and regeneration of skeletal muscles. The objective of the study was to determine the differences in eating habits of users of two different fitness cen-ters. The study included 90 subjects of both genders and different ages. Fitness centers are different according to the type of exercise they practice: CrossFit and classic fitness centers. The survey was specially designed for this type of research. In one fitness center, the survey was conducted "live" and in another “online”. The results of the research showed that there is no statistically significant difference between the respondents of the fitness center who practice classical fitness and those who practice CrossFit when choosing foods and the frequency of their use. It was also found that there was no statistically significant difference in water intake on a daily basis between the respondents of both fitness centers

I. Rodríguez-Iznaga, Yailen Costa Marrero, Tania Farias Piñeira, C. Fontaine, Lexane Paget, Beatriz Concepción Rosabal, Arbelio Penton Madrigal, V. Petranovskii et al.

Zeolitic materials incorporating mono- and bimetallic systems of nickel and cobalt were obtained from natural zeolite modified with Ni2+ and Co2+ chloride solutions through traditional ion exchange (IE) and impregnation (Imp) processes. Special attention was given to analyzing the cationic and anionic composition of the resulting materials. The catalytic potential was evaluated in the selective hydrogenation of citral, focused on the formation of unsaturated alcohols. The IE process replaced mainly Ca2+ and Na+ with Ni2+ and Co2+ cations in the zeolite phases (clinoptilolite and mordenite mix), while Imp resulted in higher metal content (2.0–2.7%) but retained significant amounts of chloride (1.9–3.8%), as confirmed by XRD and temperature-programmed reduction. The materials prepared by IE had negligible chloride content (0.02–0.07%), and their specific surface areas (138–146 m2/g) were greater than those of the materials obtained by Imp (54–67 m2/g). The bimetallic systems exhibited enhanced reducibility of the Co2+ and Ni2+ isolated cations, attributed to synergistic interactions that weakened the cation–framework binding. Catalytic activity tests showed that nickel species were primarily responsible for citronellal formation. Among all materials, the bimetallic CoNiIE catalyst, prepared by IE, was the only one to produce unsaturated alcohols, suggesting that synergistic Ni–Co interactions played a role in their formation.

As the use of autonomous mobile robots expands into dynamic and complex environments, the need for them to provide understandable explanations for their actions becomes crucial. This thesis addresses the challenge of developing explainability for robot navigation by leveraging a hybrid model that combines machine learning techniques with symbolic reasoning methods. Furthermore, the thesis explores the modeling of human explanation preferences and the impact of different explanation attributes on explanation recipients' understanding, satisfaction, and trust. The goal is to integrate different explanation aspects and approaches into a unified framework to support explainable navigation in robotics.

A. P. Cheng, Adam J. Widman, Anushri Arora, I. Rusinek, Aaron Sossin, Srinivas Rajagopalan, Nicholas Midler, William F Hooper et al.

Jelena Davidović Gidas, S. Zeljković, Nikolina Đekić, G. Đurić

Rosemary ( Rosmarinus officinalis L.) is a valuable medicinal and aromatic herb produced for its bioactive compounds and commercial applications. However, commonly used methods for rosemary propagation have various limitations that impose the need to create appropriate protocols for in vitro propagation of this species. This research aimed to evaluate the effects of light quality and plant growth regulators (PGRs) on rosemary micropropagation. Explants were cultured on Murashige and Skoog (MS) medium supplemented with varying concentrations of 6-benzylaminopurine (6-BAP), meta-Topolin (mT), 1-naphthaleneacetic acid (NAA), and indole-3-butyric acid (IBA), under different light treatments: fluorescent light (FL) and blue (BL), red (RL), and red-blue (RBL) LED lights. The highest fresh mass was formed by explants grown in medium with mT at 1.0 mg/L + 0.1 mg/L NAA under BL (88.05 ± 2.94 mg), while FL with the same PGR combination resulted in the highest dry mass (12.89 ± 0.55 mg). FL, in combination with 1.0 mg/L mT + 0.1 mg/L NAA, produced the highest number of new shoots (2.07 ± 0.04), and RL, in combination with cytokinin-free MS medium, induced the longest shoots (13.16 ± 0.37 mm). The highest number of nodes (3.91 ± 0.08) was recorded under BL in the cytokinin-free medium. For in vitro rooting, BL combined with 0.1 mg/L mT + 0.5 mg/L IBA produced the highest rooting percentage (80.00 ± 5.77%), the highest number of roots (3.92 ± 0.15), and the longest roots (75.30 ± 1.76 mm). This treatment also resulted in the highest plantlet establishment rate (71.13 ± 4.43%), confirming the synergy between BL and mT + IBA in improving the efficiency of rosemary rooting and acclimatization. These results enable a more straightforward selection of the optimal light spectrum and PGR concentrations for individual stages of the rosemary micropropagation process and highlight the potential of LED lights as a more efficient alternative to traditional fluorescent lamps. What is already known about this subject? Previous research on various plant species has shown that light quality and PGRs are important factors in regulating and directing multiplication, rooting, and general development of in vitro plants. LED lights, especially those in the blue and red spectra, showed positive effects on the processes of photomorphogenesis and, in general, the growth and development of explants. However, research on the micropropagation of rosemary has usually been focused on callus formation and active compound production and rarely on developing effective protocols for producing high-quality planting material. What are the new findings? This research showed the potential of LED lighting to outperform standard fluorescent light during in vitro rosemary propagation. Also, mT was found to be more effective than 6-BAP in promoting shoot proliferation and multiplication. To the best of our knowledge, this is the first study to simultaneously investigate the synergistic effects of light quality and PGRs on rosemary micropropagation. What are the expected impacts on horticulture? The findings of this research provide an efficient and integrated approach to the in vitro propagation of rosemary. Energy-efficient LED lights and optimal PGR combinations allow commercial growers to produce high-quality planting material.

Aleksandar Anđelković, Vesna Nikolić Jokanović, Dušan Jokanović, V. Spalevic

Understanding the impact of vegetation on organic matter content in sediments is essential for sustainable reservoir management and water quality protection. This study examined the relationship between land cover, erosion processes, and organic matter accumulation in the sediments of four small water reservoirs in the Republic of Serbia. Organic matter content was quantified and analyzed in relation to basin characteristics, including land-use composition, absolute and mean flow gradients, and sediment grain size distribution. Field sampling was conducted across the catchments of four small water reservoirs—Duboki potok, Resnik, Ljukovo, and Sot—with sediment samples collected from main tributaries and accumulation basins. A multi-method approach was employed, combining remote sensing for vegetation-cover assessment, granulometric analysis, organic matter evaluation via loss-on-ignition at 350 °C, and statistical correlation analysis to assess the influence of land use and hydrological gradients on sediment composition. The results revealed a strong correlation (R = 0.892) between forest cover and sedimentary organic matter content, confirming the significant role of vegetation in stabilizing sediments and promoting organic matter deposition. Reservoirs with higher forest and shrub cover (e.g., Sot and Duboki potok) exhibited greater organic matter accumulation (5.79–5.98%), while the agriculture-dominated Ljukovo catchment (76.85% agricultural land) recorded the lowest organic matter content (3.89%) due to increased sediment displacement and reduced erosion resistance. These findings underscore the critical role of vegetation in regulating sediment dynamics and enhancing organic matter retention in small water reservoirs. To mitigate excessive organic matter deposition and improve water quality, sustainable watershed management strategies—such as vegetation buffer strips, afforestation, and erosion control measures—are recommended.

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