bluuebunny/crossref_metadata_2025 huggingface dataset:
Hasil Belajar Matematika dan Keaktifan Peserta Didik Kelas VII SMP Negeri 8 Salatiga dengan Model RME Tahun Pelajaran 2018/2019
Authors: Windasari Ririn , Istiqlal Muhammad
Published: March 2021

Hasil belajar dan keaktifan menjadi salah satu tolok ukur keberhasilan pembelajaran di kelas. Penelitian ini bertujuan mengetahui peningkatan hasil belajar dan keaktifan peserta didik  pada mata pelajaran matematika materi penyajian data dengan model pembelajaran RME kelas VII F SMP Negeri 8 Salatiga. Jenis penelitian ini adalah jenis  Penelitian Tindakan Kelas. Subjek penelitian ini adalah peserta didik kelas VII F semester genap tahun ajaran 2018/2019 berjumlah 29 peserta didik. Teknik pengumpulan data menggunakan observasi, tes hasil belajar, angket, dan dokumentasi. Analisis data menggunakan deskriptif kualitatif dan kuantitatif. Hasil penelitian menunjukkan bahwa penerapan model pembelajaran RME  dapat meningkatkan hasil belajar dan keaktifan peserta didik  pada materi penyajian data  kelas  VII. Hal ini dapat dilihat dari nilai rata-rata hasil belajar siklus I sebesar  54,06 dan persentase ketuntasan sebesar 24,13%, kemudian meningkat pada siklus II menjadi 80,06 dengan persentase ketuntasan sebesar 89,65%. Rata-rata keaktifan peserta didik siklus I dan II indikator 1 interaksi dari 44,36% menjadi 78,62%, indikator 2 kerjasama dengan teman sekelompok dari 41,76% menjadi 71,64%, indikator 3 mengerjakan soal dan tugas dari 40,61% menjadi 72,79%, indikator 4 motivasi dalam mengikuti pelajaran dari 43,55% menjadi 70,24%. Berdasarkan hasil penelitian dapat disimpulkan bahwa penerapan model RME dapat meningkatkan hasil belajar dan keaktifan  peserta didik dalam pembelajaran matematika materi penyajian data di kelas VII F SMP Negeri 8 Salatiga.
Apakah Pembelajaran Kooperatif Tipe Two Stay Two Stray (TSTS) dapat Meningkatkan Kerjasama Siswa ?
Authors: Sari Afifah Nur Indah , Sunarwanto Sunarwanto , Listyani Endang
Published: March 2021

Penelitian ini bertujuan untuk mendeskripsikan peningkatan kemampuan kerjasama siswa dan kualitas pembelajaran melalui model pembelajaran kooperatif tipe Two Stay Two Stray. Penelitian ini adalah Penelitian Tindakan Kelas (Classroom Action Research) dengan pendekatan kualitatif. PTK ini dilaksakan di XI MIA 9 SMA N 1 Yogyakarta. Data yang dikumpulkan dengan lembar observasi keterlaksanaan pembelajaran, lembar observasi kemampuan kerjasama siswa, angket kemampuan kerjasama, dan tes. Teknik analisis data yang digunakan adalah analisis deskriptif. Hasil penelitian menunjukkan bahwa skor rata-rata kemampuan kerjasama siswa dalam pembelajaran matematika yang diperoleh meningkat dari kondisi awal yaitu pada kategori sedang meningkat menjadi pada kategori tinggi pada siklus pertama dan siklus kedua. Pada kondisi awal, rata-rata skor kemampuan kerjasama siswa adalah 84 sedangkan pada akhir siklus pertama menjadi 87 dan pada akhir siklus kedua 90. Persentase skor rata-rata siswa dalam kategori sangat tinggi diperoleh sebesar 10% dan siswa dalam kategori tinggi mencapai 66,67%. Hasil observasi kemampuan kerjasama siswa diperoleh sebesar 73,33% siswa mencapai kategori minimal tinggi. Persentase kelulusan siswa yang memperoleh nilai hasil belajar lebih dari KKM pada siklus I sebesar 76,67% dan pada siklus II sebesar 90%. Dengan demikian, setelah 2 siklus, pembelajaran menggunakan pembelajaran kooperatif tipe Two Stay Two Stray dapat meningkatkan kemampuan kerjasama siswa. Hal tersebut juga diikuti dengan meningkatnya persentase keterlaksanaan pembelajaran dari sklus I sebesar 84,48% pada kegiatan guru dan 82,76% pada kegiatan siswa meningkat menjadi 88,51% di akhir siklus II baik untuk kegiatan guru maupun kegiatan siswa.Kata kunci : penelitian tindakan kelas, kerjasama, Two Stay Two Stray
Unpacking implementation capacity and contexts for degree reclamation strategies: What factors move the equity needle?
Authors: Taylor Jason , Rubin Paul , Kauppila Sheena , Davis Leanne
Published: March 2021

This paper used data from a multi-institutional study of community colleges developing and implementing degree reclamation strategies (adult reengagement and reverse credit transfer) to understand and unpack the factors that influence implementation and capacity development. The data come from seven colleges that are implementing equity-focused degree reclamation strategies aimed to reduce the population of “some college, no degree.” The research team used an interdisciplinary lens to identify these factors drawing from literature on capacity-building. Prior to the start of implementation, researchers surveyed institutions and institutional stakeholders to assess baseline capacity, and they tracked institutional participation and engagement in the strategy development and implementation process. This paper highlights findings from this research to identify which factors are most related to implementation variation and strategy outcomes.
Analysing self-regulated learning strategies of MOOC learners through self-reported data
Authors: Alonso-Mencía M. Elena , Alario-Hoyos Carlos , Estévez-Ayres Iria , Delgado Kloos Carlos
Published: March 2021

Massive open online courses (MOOCs) require registered learners to be autonomous in their learning. Nevertheless, prior research studies showed that many learners lack the necessary self-regulated learning (SRL) skills to succeed in MOOCs. This research study aimed to gain insights into the relationships that exist between SRL and background information from MOOC learners. To this end, a series of three MOOCs on computer programming offered through edX were used to collect self-reported data from learners using an adaptation of the Motivated Strategies for Learning Questionnaire. Results show significant differences in general learning strategies and motivation by continent, prior computing experience and percentage of completed MOOCs. Men reported higher motivation than women, whereas pre-university learners needed further guidance to improve their learning strategies.
Universal Design Principles for Older People and Older People with Disabilities During the COVID-19 Pandemic
Authors: Chrzanowska Olga
Published: March 2021

This study aims to investigate the existing situation of the COVID-19 pandemic from an architectural and urban perspective. The problem analyzed in the study was whether and how universal design could be a useful tool in creating a meaningful response to social repercussions caused by COVID-19. Of the various issues faced today, this study focused on solving the issue of isolation and reducing infections in elderly and elders with disabilities by introducing architectural and spatial modifications. This research showed that all seven universal design principles when introduced at the architectural and urban levels can solve various issues that elderly people face today during the pandemic. It is executed through administrative and institutional push toward better accessibility and inclusion in a build environment that also works for general public interest.
Relapses in the process of desistence from offending
Authors: Muskała Maciej
Published: March 2021

Many offenders follow the „ zigzag path”, interlacing many times criminal and noncriminal stages. The aim of this survey review is to show, on the example of the Self- Regulatory Model of Relapse Prevention analyses (SRM-r in modified version) the variety of ways and courses of action that an offender (mainly sexual) may follow in the process of desistance from offending.
Evaluating Visual Cues Modulates Their Representation in Mouse Visual and Cingulate Cortex
Authors: Wal Alexandra , Klein Frederike Johanna , Born Gregory , Busse Laura , Katzner Steffen
Published: March 2021

Choosing an action in response to visual cues relies on cognitive processes, such as perception, evaluation, and prediction, which can modulate visual representations even at early processing stages. In the mouse, it is challenging to isolate cognitive modulations of sensory signals because concurrent overt behavior patterns, such as locomotion, can also have brainwide influences. To address this challenge, we designed a task, in which head-fixed mice had to evaluate one of two visual cues. While their global shape signaled the opportunity to earn reward, the cues provided equivalent local stimulation to receptive fields of neurons in primary visual (V1) and anterior cingulate cortex (ACC). We found that mice evaluated these cues within few hundred milliseconds. During this period, ∼30% of V1 neurons became cue-selective, with preferences for either cue being balanced across the recorded population. This selectivity emerged in response to the behavioral demands because the same neurons could not discriminate the cues in sensory control measurements. In ACC, cue evaluation affected a similar fraction of neurons; emerging selectivity, however, was stronger than in V1, and preferences in the recorded population were biased toward the cue promising reward. Such a biased selectivity regime might allow the mouse to infer the promise of reward simply by the overall level of activity. Together, these experiments isolate the impact of task demands on neural responses in mouse cerebral cortex, and document distinct neural signatures of cue evaluation in V1 and ACC.

SIGNIFICANCE STATEMENT
Performing a cognitive task, such as evaluating visual cues, not only recruits frontal and parietal brain regions, but also modulates sensory processing stages. We trained mice to evaluate two visual cues, and show that, during this task, ∼30% of neurons recorded in V1 became selective for either cue, although they provided equivalent visual stimulation. We also show that, during cue evaluation, mice frequently move their eyes, even under head fixation, and that ignoring systematic differences in eye position can substantially obscure the modulations seen in V1 neurons. Finally, we document that modulations are stronger in ACC, and biased toward the reward-predicting cue, suggesting a transition in the neural representation of task-relevant information across processing stages in mouse cerebral cortex.
Population Coding of Natural Electrosensory Stimuli by Midbrain Neurons
Authors: Metzen Michael G. , Chacron Maurice J.
Published: March 2021

Natural stimuli display spatiotemporal characteristics that typically vary over orders of magnitude, and their encoding by sensory neurons remains poorly understood. We investigated population coding of highly heterogeneous natural electrocommunication stimuli inApteronotus leptorhynchusof either sex. Neuronal activities were positively correlated with one another in the absence of stimulation, and correlation magnitude decayed with increasing distance between recording sites. Under stimulation, we found that correlations between trial-averaged neuronal responses (i.e., signal correlations) were positive and higher in magnitude for neurons located close to another, but that correlations between the trial-to-trial variability (i.e., noise correlations) were independent of physical distance. Overall, signal and noise correlations were independent of stimulus waveform as well as of one another. To investigate how neuronal populations encoded natural electrocommunication stimuli, we considered a nonlinear decoder for which the activities were combined. Decoding performance was best for a timescale of 6 ms, indicating that midbrain neurons transmit information via precise spike timing. A simple summation of neuronal activities (equally weighted sum) revealed that noise correlations limited decoding performance by introducing redundancy. Using an evolution algorithm to optimize performance when considering instead unequally weighted sums of neuronal activities revealed much greater performance values, indicating that midbrain neuron populations transmit information that reliably enable discrimination between different stimulus waveforms. Interestingly, we found that different weight combinations gave rise to similar discriminability, suggesting robustness. Our results have important implications for understanding how natural stimuli are integrated by downstream brain areas to give rise to behavioral responses.

SIGNIFICANCE STATEMENTWe show that midbrain electrosensory neurons display correlations between their activities and that these can significantly impact performance of decoders. While noise correlations limited discrimination performance by introducing redundancy, considering unequally weighted sums of neuronal activities gave rise to much improved performance and mitigated the deleterious effects of noise correlations. Further analysis revealed that increased discriminability was achieved by making trial-averaged responses more separable, as well as by reducing trial-to-trial variability by eliminating noise correlations. We further found that multiple combinations of weights could give rise to similar discrimination performances, which suggests that such combinatorial codes could be achieved in the brain. We conclude that the activities of midbrain neuronal populations can be used to reliably discriminate between highly heterogeneous stimulus waveforms.
Propriedades Temporais do Futuro Simples em Português Europeu
Authors: Cunha Luís Filipe
Published: March 2021

O objetivo central do presente trabalho é o de discutir algumas das propriedades temporais que caracterizam o Futuro Simples em Português Europeu. Começaremos por demonstrar que, embora este tempo gramatical veicule frequentemente informação de cariz modal, existem inúmeros contextos em que a sua função é claramente a de localizar uma situação num intervalo futuro. Nesse sentido, discutiremos algumas propostas de análise para o Futuro Simples que nos permitam dar conta das suas propriedades temporais. Assumiremos que o referido tempo gramatical exprime tipicamente uma relação de posterioridade no que diz respeito ao momento da enunciação. Uma tal abordagem permite-nos dar conta não apenas dos casos de mera localização das eventualidades no eixo temporal, mas também das restrições aspetuais a que a designada leitura conjetural do Futuro Simples está sujeita. Finalmente, estabeleceremos uma comparação sistemática entre as propriedades temporais do Futuro Simples e da construção ir (no Presente do Indicativo) + Infinitivo, sustentando a ideia de que esta última apresenta restrições adicionais a nível temporal – em particular, a imposição de uma fronteira posterior a t0 para além da qual as situações não se poderiam estender –, o que explicaria a total impossibilidade da sua comparência em configurações de sobreposição ao momento da enunciação, mesmo quando estão em causa predicações estativas.
How Perceived Security Risk Influences Acceptance of Virtual Shopping Walls
Authors: Jahn Steffen , Langer Ann-Christin , Elshiewy Ossama , Boztuğ Yasemin
Published: March 2021

Virtual shopping walls are innovative digital stores that can be placed in highly frequented areas of public transport, such as bus or subway stations. These walls resemble shelves of a stationary supermarket and allow convenient shopping with the smartphone combined with home delivery. The goal of the present research is to shed light on what drives widespread use of this store concept. Complementing traditional models of technology acceptance, this work examines the impact of perceived security risk with special emphasis on its moderating effect on the perceived usefulness-behavioral intention relationship. We find that the intention to use virtual shopping walls is driven by perceived ease of use and perceived usefulness, while perceived security risk acts like a barrier to acceptance. The negative effect of high perceived security risk, however, is mitigated by high perceived usefulness. This means that high perceived usefulness of virtual shopping walls can compensate for increased risk perceptions in a significant way, providing important insights for providers of virtual shopping walls.
Soft nitrogen and sulfur incorporated into enzymatic hydrolysis lignin as an environmentally friendly antioxidant and mercury adsorbent
Authors: Huang Wen-Xin , Zhang Yu-Hua , Ge Yuan-Yuan , Qin Li , Li Zhi-Li
Published: March 2021

Soft donors of nitrogen and sulfur were incorporated into enzymatic hydrolysis lignin (EHL-NS) to make it suitable for multiple applications. Characterizations of the environmentally friendly material by Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, and thermogravimetric analysis confirmed the layered porous structure with nitrogen and sulfur groups. It exhibited high antioxidant activity due to the strong electron-donating capability of the soft donors. Moreover, the soft donors also contributed to the chemical complexation of Hg(II) with EHL-NS, which distinctly enhanced the adsorption of Hg(II) in water (Qe=180 mg/g, 25 °C). Given that the free radicals were highly effective at scavenging and adsorption, the functionalized enzymatic hydrolysis lignin is expected to serve a useful role.
A coupling model based on grey relational analysis and stepwise discriminant analysis for wood defect area identification by stress wave
Authors: Li Xin , Qian Wei , Cheng Liting , Chang Lihong
Published: March 2021

Based on the experimental idea of reverse simulation, a quantitative area of hole was excavated at the sectional center of a wood specimen. The excavation area was 1/32S, 1/16S, 1/8S, 1/4S, and 1/2S (where S represents cross-sectional area of the complete specimen) and stress wave nondestructive testing of six sensors was performed. The stress wave propagation paths were statistically summarized to obtain the stress wave propagation velocity (Va) for two adjacent sensors, the stress wave propagation velocity (Vb) for two separated sensors, and the stress wave propagation velocity (Vc) for two opposite sensors. Furthermore, by analyzing the advantages and disadvantages of grey relation and stepwise discriminant model when both of them were used alone, a coupling model generated from them was established to dispose the test data. The attenuation ratios Ψa, Ψb, and Ψc of stress wave under three propagation paths and their relation ratios Va/Vb, Vb/Vc, and Va/Vc, a total of six groups of measured data, were selected as discriminant factors for the hole area grade of the wood specimen. The verification results showed that the discriminant accuracy of the coupling model was 100%, and it was concluded that the attenuation ratio (Ψb) of the stress wave propagation velocity for two separated sensors had the strongest discriminant ability against cross-sectional area of the specimen.
Effect of an electro-Fenton process on the biodegradation of lignin by Trametes versicolor
Authors: Shen Jiahe , Hou Lipeng , Sun Haipeng , Hu Mingyang , Zang Lihua , Zhang Zudong , Ji Dandan , Zhang Fengshan
Published: March 2021

A synergistic effect was found between the electro-Fenton (E-Fenton) process and a white-rot enzyme (Trametes versicolor) system relative to the degradation of dealkaline lignin. The hydrogen peroxide produced by the E-Fenton process reacted with Fe2+ on the cathode to generate a large number of hydroxyl radicals. These hydroxyl radicals directly degraded various functional groups in lignin, which led to the quick initiation of lignin peroxidase (LiP) and manganese peroxidase (MnP) enzymatic hydrolysis and accelerated the progress of lignin biodegradation. In addition, the hydroxyl radicals produced by the Fenton reaction converted nonphenolic lignin into phenolic lignin, further promoting the ability of manganese peroxidase and laccase to degrade the lignin. Additionally, the Fe3+ secreted by white-rot fungi accelerated the regeneration of Fe2+ on the composite cathode, which sustained the lignin degradation system. In the synergistic system, mycelium growth was significantly improved, with the maximum growth amount reaching 2.3 g and the lignin degradation rate reaching 84.5%, the activity of the three enzymes increased with the increase of currents over 96 h. Among them, the activity of MnP increased significantly to 402 U/L.
Natural fiber-based composites with high hydrophobic, magnetic, and EMI shielding properties via iron oxide in situ synthesis and copper film deposition
Authors: Wang Quanliang , Tang Jie , Xiao Shengling , Wang Min , Shi Sheldon Q.
Published: March 2021

A sandwich-structured natural fiber-based magnetic composite, without the use of a binder, was developed in this study. It was fabricated via in situ synthesis, densification, and magnetron sputtering processes. The chemical composition, crystal structure, microstructure, and thermal stability were characterized via X-ray photoelectron spectroscopy, energy-dispersive spectroscopy, X-ray diffraction, scanning electron microscope, and thermogravimetric analysis. The hydrophobic, magnetic, and electromagnetic interference shielding properties were investigated by measuring the static water contact angle, the magnetic hysteresis loops, and the shielding effectiveness. The resulted composites exhibited a unique inner structure with a larger iron oxide size and content (492 nm and 26.1 wt%) on the interlayer surface in comparison to the core layer (135 nm and 18.7 wt%). The magnetic response can be controlled by the loaded iron oxide content and the copper film deposition. Sputtering copper film changed the surface free energy, and created rough micro-/nanostructures, which yielded a highly hydrophobic nature (133° in water contact angle), and approximately 99.2% of the electromagnetic energy was shielded by the 0.8 mm thick composite.
Hydrogen: state of the art and directions of future use
Authors: IM Karp
Published: March 2021

The use of hydrogen as one of the most promising areas of European Green Deal, i.e. the transition to a carbon-free economy (decarbonization) is considered. In the world energy sector, the problem of production and use of "green" hydrogen produced by electrolysis attracts considerable attention. Per 1m3 of electrolytic hydrogen consumes from 4 to 5kWh of electricity, despite the fact that it contains chemical energy of 3.0kWh. The calorific value of hydrogen is 3.3 times less than that of methane. Hydrogen properties such as wide explosive limits, high torch propagation speed, and corrosion activity against many metals require special measures during transportation, storage, and use. Economically justified technologies for the use of hydrogen do not yet exist. As one of the effective options are considered the prospects of transporting a mixture of hydrogen and natural gas by main and distribution pipelines. Most hydrogen projects are funded by a grant. The driver of hydrogen energy is the prevention of anthropogenic impact on climate change, which in itself is problematic. Bibl.9, Table 1.
Nonpharmacological Interventions for Pediatric Migraine: A Network Meta-analysis
Authors: Koechlin Helen , Kossowsky Joe , Lam Thanh Lan , Barthel Johannes , Gaab Jens , Berde Charles B. , Schwarzer Guido , Linde Klaus , Meissner Karin , Locher Cosima
Published: March 2021

CONTEXT:

Migraine is a common neurologic disorder in children and adolescents. However, a comparison of multiple nonpharmacological treatments is lacking.

OBJECTIVE:

To examine whether nonpharmacological treatments are more effective than waiting list and whether there are differences between interventions regarding efficacy.

DATA SOURCES:

Systematic review and network meta-analysis of studies in Medline, Cochrane, Embase, and PsycINFO published through August 5, 2019.

STUDY SELECTION:

Randomized controlled trials of nonpharmacological treatments in children and adolescents diagnosed with episodic migraine.

DATA EXTRACTION:

Effect sizes, calculated as standardized mean differences (SMDs) for the primary outcome efficacy, were assessed in a random-effects model.

RESULTS:

Twelve studies (N = 576) were included. When interventions were classified into groups on the basis of similarity of treatment components, self-administered treatments, biofeedback, relaxation, psychological treatments, and psychological placebos were significantly more effective than waiting list with effect sizes ranging between SMD = 1.14 (95% confidence interval, 0.09 to 2.19) for long-term psychological placebos to SMD = 1.44 (95% confidence interval, 0.26 to 2.62) for short-term self-administered treatments. However, when all interventions were examined individually (ie, 1 node per intervention), none were significantly more effective compared with waiting list, mainly because of lack of statistical power.

LIMITATIONS:

Because of our focus on pediatric migraine, only a small number of studies could be included.

CONCLUSIONS:

Our findings reveal that components of nonpharmacological interventions are effective in treating pediatric migraine. Some effects have to be interpreted carefully because they are based on small studies. Future researchers should identify factors associated with individual responses in large, multicentered studies.
La managerialización de las relaciones estatales en Argentina (2015- 2019): ¿Cambiemos logró cambiarnos?
Authors: Farias María Laura
Published: March 2021

Producto de su reciente surgimiento, analizaremos la inserción directa de los principales articuladores del management en cargos de alta dirección pública en el Estado argentino  y su impacto en la dinámica organizacional. La asunción de Mauricio Macri supuso la designación de altos funcionarios que provenían de la dirección de grandes empresas y que buscaron instrumentar  una transformación de la naturaleza estatal (concebida como ineficiente y burocrática), hacia una más afín a los criterios manageriales de agilidad, modernidad y eficacia. Estudiando la inserción  de estos managers en la estructura estatal, analizaremos los modos en que su participación en la gestión pública influyó  en sus concepciones respecto del Estado y sus trabajadores, así como también en su percepción sobre la subjetividad estatal y “lo público”. Para este propósito, nos basamos en un abordaje cualitativo a través de entrevistas y análisis de materiales documentales que nos permitirá conocer cómo se perciben las características del Estado y sus empleados, arrojando también reno- vadas concepciones por parte de los entrevistados. Por último, analizaremos las ideas previas de los managers al Estado, así como los preconceptos con los que estos sujetos concebían a los trabaja- dores estatales, para conocer cómo su paso por el Estado ha atravesado esas conceptualizaciones.
Organizational couplings: a literature review
Authors: Arango-Vasquez Leonel , Gentilin Mariano
Published: March 2021

The loosely coupled systems (LCS) perspective emerged as a new way to understand the organizational structure from the field of Organization Studies. The purpose of this article is to pres­ent the main features of previous research studies that have addressed the perspective of loosely coupled systems. This article is based on a systematic literature review of 76 papers published dur­ing a 36-year period (1983-2019). The findings indicate that the main concepts studied around this perspective have been loose coupling, tight coupling, decoupling, degree of coupling, and coupling mechanisms, which are analyzed considering the dialectical relationship between distinctiveness and responsiveness. Likewise, the study of organizational couplings has been extensively devel­oped through qualitative methodology with case studies, interviews and documentary reviews. In particular, there are two theoretical frameworks broadly used along with this perspective, the sociological new institutionalism and the theory of normal accidents, which give rise to future research on topics such as decoupling and the normality of accidents, among others. This article contributes to the discussion of organizational ties by highlighting the contemporary relevance of the LCS perspective, its usefulness for understanding current and future organizational issues in the field of Organization Studies, and encouraging greater adoption of LCS analysis in Latin America. Additionally, this paper provides conceptual clarity on the main categories of organizational cou­plings and its operationalization.
Hacia una teoría lúdica de la organización
Authors: Saldaña Rosas Alejandro José , Aguilar Contreras Aurora Irazema
Published: March 2021

En este trabajo se explora la dicotomía racionalidad-juego desde un abordaje construido con la perspectiva del pensamiento complejo. Se sostiene el postulado de que las teorías de la organización no han dado cuenta suficiente de la matriz lúdica de sus reflexiones o, cuando más, la han incorporado tangencialmente, como expresión de una no-racionalidad indeseable, pero in-evitable, o como un recurso al servicio de la productividad y la eficiencia. La matriz lúdica tiene una presencia vital que paulatinamente ha aparecido en el campo de reflexión de los estudios organizacionales, en investigaciones sobre las emociones, la estética, el humor, el aprendizaje, las narrativas, los rituales, la vida simbólica y, en general, sobre lo que agrupa la noción de cultura organizacional. Asimismo, la matriz lúdica en las organizaciones se expresa de muchas otras formas: en las ferias comerciales e industriales; en dinámicas y técnicas de capacitación laboral; como recurso para detonar la creatividad e incentivar la innovación; como dispositivo para el diseño de estrategias de negocios. Para los estudios organizacionales es importante reconocer que algunas de sus vetas de investigación tienen una matriz lúdica. Este trabajo es parte de una reflexión más amplia sobre el modo capitalista de seducción. En esta tesitura se propone la noción de capital lúdico como piedra angular del proceso de seducción en el capitalismo.
The age U-shape in Europe: the protective role of partnership
Authors: Clark Andrew E. , Greulich Angela , d’Albis Hippolyte
Published: March 2021

In this study, we ask whether the U-shaped relationship between life satisfactionand age is flatter for individuals who are partnered. An analysis of cross-sectionalEU-SILC data indicates that the decline in life satisfaction from the teens to thefifties is almost four times larger for non-partnered than for partnered individuals,whose life satisfaction essentially follows a slight downward trajectory with age.However, the same analysis applied to three panel datasets (BHPS, SOEP andHILDA) reveals a U-shape for both groups, albeit somewhat flatter for the partneredthan for the non-partnered individuals. We suggest that the difference between thecross-sectional and the panel results reflects compositional effects: i.e., there isa significant shift of the relatively dissatisfied out of marriage in mid-life. Thesecompositional effects tend to flatten the U-shape in age for the partnered individualsin the cross-sectional data.
Anatomical variations and interconnections of the superior peroneal retinaculum to adjacent lateral ankle structures: a preliminary imaging anatomy study
Authors:   Musculoskeletal Radiology Practice, Heraklion Crete Greece & Medical School, European University of Cyprus, Cyprus, Drakonaki Eleni E. , Gataa Khaldun Ghali ,   Department of Musculoskeletal Radiology, Sahlgrenska University Hospital, Sweden,   Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden, Solidakis Nektarios ,   Department of Musculoskeletal Radiology, Sahlgrenska University Hospital, Sweden,   Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden, Szaro Paweł ,   Department of Musculoskeletal Radiology, Sahlgrenska University Hospital, Sweden,   Department of Radiology, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Sweden,   Department of Clinical and Descriptive Anatomy, Medical University of Warsaw, Poland
Published: March 2021

Aim: This imaging anatomy study aimed at detecting anatomical variations and potential interconnections of the superior peroneal retinaculum to other lateral stabilizing structures. Materials and methods: We retrospectively reviewed the imaging archives of 63 patients (38 females, 25 males, mean age 32.7, range 18–58 years) with available ankle US, MR and CT images to detect whether US and MR can detect the presence of interconnections between the superior peroneal retinaculum and the anterior talofibular ligament, inferior extensor retinaculum and peroneal tendon sheath. We evaluated the presence of common anatomical variations including low peroneus brevis muscle belly, peroneal tubercle, os peroneum, and retromalleolar fibular groove shape in relation to the presence of superior peroneal retinaculum connections. Results: The connections of the superior peroneal retinaculum can be revealed on magnetic resonance imaging (MRI) and ultrasound (US). The connection to the anterior talofibular ligament was located (a) inferior to the lateral malleolus, (b) at the level of the lateral malleolus and (c) on both levels, respectively (a) 49.2% on MRI and 39.7% on US, p <0.05, (b) 44.4% and 58.7%, p <0.05, 36.5% and (c) 27%, p <0.05. Superior peroneal retinaculum–inferior extensor retinaculum (MRI 47.6%, US 28.6% p <0.001) and superior peroneal retinaculum–peroneal tendon sheath (MRI 22.2%, US 25.4% p >0.05) connections were also found both on MR and US. Conclusion: Ankle US and MR revealed interconnections between the superior peroneal retinaculum and the anterior talofibular ligament, inferior extensor retinaculum, and superior peroneal retinaculum. Our results are a starting point for further studies on the connections of the superior peroneal retinaculum and the applicability of ultrasound and MRI in assessing their occurrence. Knowledge of the anatomical connections of the superior peroneal retinaculum may help radiologists with the assessment of lateral ankle injuries, and surgeons with treatment planning.
Role of ultrasound in the diagnosis of paediatric acute osteomyelitis
Authors:   Department of Radiology, Military Hospital Jodhpur, India, Paliwal Amit Kumar , Sahdev Ravinder ,   Department of Radiology, Military Hospital Secundrabad, India, Deshwal Ankur ,   Department of Orthopaedics, Military Hospital Jodhpur, India, Ram Birma ,   Department of Radiology, Military Hospital Jodhpur, India
Published: March 2021

Aim: The aims of our study were to evaluate cases of extremity pain or swelling in paediatric patients using USG to diagnose acute osteomyelitis, and correlate USG findings with MRI findings. Material and methods: 18 paediatric patients with extremity pain or swelling were evaluated. After the clinical and laboratory work-up, imaging was done using radiographic examination, USG and MRI of the affected limb. Results: 5 patients (27.8%) out of 18 were diagnosed with acute osteomyelitis based on USG findings, confirmed by MRI and surgical drainage. The mean age of the patients with acute osteomyelitis was 8.2 years. Male children were more commonly affected as compared to female. The distal metaphysis of the femur was the most common site involved (80%). The right lower limb was more commonly affected. The most frequent presentation was pain at the affected site. On USG, deep soft tissue fluid collection around the bone was present in all cases (100%). Periosteal thickening or elevation with subperiosteal fluid collection was seen in 4 cases (80%). Increased vascularity within or around the periosteum on colour Doppler was seen in 4 cases (80%). Conclusions: Acute osteomyelitis is a common entity in the paediatric population, presenting with acute limb pain and swelling. Early diagnosis and management of acute osteomyelitis are essential to prevent serious complications. USG can play an important role in the early diagnosis of paediatric acute osteomyelitis, and should be incorporated into the treatment protocols followed in cases of suspected acute osteomyelitis. MRI should be reserved as problem-solving tool.
Evaluation of parenchymal vascularity of the thyroid gland with vascularization index by color superb microvascular imaging in patients with Graves’ disease
Authors:   Department of Radiology, Selçuk University School of Medicine, Konya, Turkey, Kılınçer Abidin , Durmaz Mehmet Sedat ,   Department of Radiology, Selçuk University School of Medicine, Konya, Turkey,   Department of Radiology, Selçuk University School of Medicine, Konya, Turkey, Kıraç Cem Onur ,   Division of Endocrinology, Department of Internal Medicine, Selçuk University School of Medicine, Konya, Turkey, Baldane Süleyman ,   Division of Endocrinology, Department of Internal Medicine, Selçuk University School of Medicine, Konya, Turkey, Ateş Fatih ,   Department of Radiology, Selçuk University School of Medicine, Konya, Turkey, Batur Abdüssamet ,   Department of Radiology, Selçuk University School of Medicine, Konya, Turkey
Published: March 2021

Aim of the study: To determine the parenchymal vascularity of the thyroid gland with color superb microvascular imaging in patients with Graves’ disease, and compare the vascularization index values with healthy subjects. Materials and methods: The thyroid glands of 37 patients whose laboratory and clinical findings were consistent with Graves’ disease, and 40 asymptomatic subjects with normal laboratory values, were examined using color superb microvascular imaging. Measurements of the vascularization index were performed with a free region of interest which was drawn along the outer margin of the gland on the color superb microvascular imaging mode. The vascularization index values obtained in the Graves’ disease and control groups were compared. A correlation analysis was performed between the vascularization index values and laboratory and grayscale US parameters. Results: The median vascularization index value of the thyroid parenchyma in patients with Graves’ disease was significantly higher than in the asymptomatic group [median (min–max); 12 (2.3–32.1) vs 5.04 (1.1–10.8), p <0.001]. When the cutoff value of the vascularization index is determined as 6.3, Graves’ disease can be diagnosed with 83.8% sensitivity and 70% specificity. Conclusions: The vascularization index obtained with color superb microvascular imaging can be a quantitative indicator of parenchymal vascularity in the diagnosis of Graves’ disease, and serve as a supportive tool.
Paediatric small-bowel intussusception on ultrasound – a case report with differentiating features from the ileocolic subtype
Authors:   Department of Radiodiagnosis and Imaging, Military Hospital Mathura, India, Mendiratta Pushkar , Yadav Anurav ,   Department of Surgery, Military Hospital Mathura, India, Borse Nitin ,   Department of Surgery, Military Hospital Mathura, India
Published: March 2021

Aim of the study: Intussusception is a common paediatric emergency which can be diagnosed with relative certainty by ultrasonography in trained hands. Both the ileocolic and small-bowel intussusception have overlapping clinical features and imaging findings on ultrasound. The aim is to differentiate between both subtypes based on selective differentiating features which should always be looked for while performing an ultrasound examination in suspected cases. Differentiating between the two subtypes is essential, since patient management may differ depending on the subtype. Case description: We present a case of a 12-year-old boy who presented to our hospital with pain in the abdomen. An emergency ultrasound revealed findings suggestive of small- bowel intussusception. A brief description of the differentiating points from the ileocolic subtype is also described. Conclusions: Based on the features described, it is possible to confidently differentiate between the two subtypes, which is a guiding factor for treatment.
Ultrasound guided injection of the rotator interval – Gaurav-Botchu technique
Authors:   Department of Radiology, MGM Medical College and Hospital, Jaipur, India, Sharma Gaurav Kant , Botchu Rajesh ,   Department of Musculoskeletal Radiology, Royal Orthopaedic Hospital, Birmingham, UK
Published: March 2021

Ultrasound-guided injection of the shoulder via the rotator interval can be challenging. The procedure is used for arthrograms, hydrodilatation and intra-articular glenohumeral joint injections. The conventional approach to the rotator interval is from lateral to medial. However, the placement of the needle in the target zone i.e. between the coracohumeral ligament and the long head of the biceps, can be difficult and challenging. Inadvertent injection performed with the needle in the long head of the biceps tendon can result in a biceps tendon rupture. We describe a new method (Gaurav-Botchu technique) to access the target zone (between the coracohumeral ligament and the long head of the biceps tendon) via a medial to lateral approach, which increases the target zone.
The Features of the Legal Regulation of a Commercial Transaction in Tax Relations
Authors: Farkhutdinov Ruslan
Published: March 2021

Introduction: in the paper the author proposes to consider the interbranch relations of civil and other branches of law, for example, the financial one, proposing a resolution of establishing the “depth” of the limit of the synthesis of public economic interest in a commercial transaction, defining this conceptual framework, and to develop the proposals for resolving this problem in a practical aspect, applying the criteria (categories) of denoting the limit. The purpose and novelty: the scientific novelty of this topic lies in the fact that, first, it considers and decides the important legal problems of protection of the parties to the contract against the influence of public interest, and secondly, it provides the criteria for the evaluation of limits of mutual synthesis of public to private and private to public, and thirdly, it provides for the discussion and development of a new conceptual framework of interbranch relations. Methods: the paper uses the comparative, formal-legal and functional research methods. Results: the results of the research on the features of the legal regulation of the interbranch relations between the civil and financial branches indicate the existence of problems and contradictions in their enforcement by the subjects, in particular, the issue of the influence of public economic interest in a commercial transaction is considered. Conclusion: the protection of public economic interest in a commercial transaction is a “mirror” model for protecting the rights of the parties in such a transaction. Thus, the tools for protecting the violated rights of public economic interest are identical to the tools for protecting rights in the presence of vertical relations between the parties in a commercial transaction. The application of criteria for assessing the limit of synthesis of public economic interest in a transaction is a priority task, not only in the material terms, but also in virtual reality.
Mechanical behaviour of rock samples containing multiple parallel joints during shearing
Authors: Huang N. , Han G. , Liu R. , Jiang Y.
Published: March 2021

This study experimentally investigated the influence of number of joints on the mechanical behaviour of multi-joint samples during shearing under constant normal stiffness (CNS) boundary conditions. A series of samples that have different surface roughness and different numbers of joints are prepared, and the variations in shear stress, normal stress, normal displacement are analysed. The relationship between surface resistance index (SRI), defined as the ratio of shear stress to normal stress, and number of joints are estimated. The results show that with the increment of number of joints, the damage degree of the samples increases. For a multi-joint sample, the middle joint is most significantly damaged. When the shear displacement is small, the shear stress decreases with increasing the number of joints. However, when the shear displacement is large, the shear stress does not exhibit clear relationships with the number of joints. The SRI has clear peak values against shear displacement, and the peak SRI decreases linearly by increasing the number of joints, while the peak shear displacement increases following quadratic functions. Finally, two new regression functions are proposed to predict the variations in peak SRI and peak shear displacement for multi-joint samples during shearing under CNS boundary conditions.
From Siberian Fields to Ministerial Posts
Authors:   Baikal State University, Tsykunov Grigory
Published: March 2021

Review of the book by V.I. Pokorsky, which is dedicated to graduates of the Irkutsk State Institute (Ezhevsky Agrarian University), their professional and social activities. The book traces the biographies of hundreds of people for whom a higher educational institution determined their fate, involvement in labor achievements in the soviet and modern periods.
Marianne Hirsch and Leo Spitzer, School Photos in Liquid Time: Reframing Difference
Authors: du Plessis Rory
Published: March 2021

Marianne Hirsch and Leo Spitzer, School Photos in Liquid Time: Reframing Difference (Seattle: University of Washington Press, 2020), 264 pp, ISBN 978-0295746548. In the path-breaking book School Photos in Liquid Time, Marianne Hirsch and Leo Spitzer provide a novel study of school photographs. Unlike family photo albums and archived photographic records, school photographs have received minimal scholarly interest (p. 26). To this end, the book is commended for offering a full-length study devoted to school photos and for directing academic attention to a genre of vernacular photography that has received only a paucity of scholarly and historical investigation. The book offers a sustained focus on school photos taken in 'times of extremity' (p. 16), for example, of Jewish children in Nazi ghettos, and black children during the colonial period of the late nineteenth and early twentieth centuries. Significantly, for this group of school photos, Hirsch and Spitzer develop a '"liquid" and multitemporal reading' (p. 13) that seeks to underscore how the meaning of photographs can develop 'in unforeseen directions when they are viewed and re-viewed by different people in different presents. In "liquid time" they are not fixed into static permanence; rather, they remain dynamic, unfixed, as they acquire new meanings, in new circumstances' (p. 13).
In and Out of Sight: The Afterlife of Official Photography from Idi Amin's Uganda
Authors: Vokes Richard
Published: March 2021

This article examines the output of Uganda's official Photographic Section from the years of the Idi Amin regime (1971-9), an archive of 60,000 black and white images from which have recently come to light in the stores of the Uganda Broadcasting Corporation in Kampala. Drawing on recent developments in African visual studies, the article focuses in particular upon what this archive reveals about photographic circulations in and from Amin's Uganda. It finds that this new trove of negatives -when compared with press archives from around the world - is especially revealing of a growing nexus between official photography and all kinds of commercial photographies in the 1970s. This nexus played a key role in shaping both how the Amin regime was pictured at the time, and how its afterlife has continued to reflect down to the present time.
How Do We Look?
Authors: Peffer John
Published: March 2021

In South Africa under apartheid, portrait images displayed in private homes emphasised the dignity of their subjects and the stability of family life during a period of indignity and social upheaval. But when interviewing families about them, one often encounters sensitivity issues of the sort too often passed over by scholars and curators who valorise studio practices without consulting the actual subjects of the images. These include a range of anxieties about repackaging for display in new contexts and for broader audiences, as well as basic copyright and authorship concerns in common with other African and 'family' photographies. The particular anxieties themselves speak to the local histories of how these self-images were used and lived. This essay argues for a closer consideration and a new ethics for looking at and writing about these pictures. It is based on research since 2010 on family collections of photographs in South Africa's Black urban neighbourhoods.