361 research outputs found
Pain-induced changes in motor unit discharge depend on recruitment threshold and contraction speed
No full textAt high forces, the discharge rates of lower and higher threshold motor units (MU) are influenced in a different way by muscle pain. These differential effects may be particularly important for performing contractions at different speeds since the proportion of lower and higher threshold MUs recruited varies with contraction velocity. We investigated whether MU discharge and recruitment strategies are differentially affected by pain depending on their recruitment threshold (RT), across a range of contraction speeds. Participants performed ankle dorsiflexion sinusoidal-isometric contractions at two frequencies (0.25Hz and 1Hz) and two modulation amplitudes [5% and 10% of the maximum voluntary contraction (MVC)] with a mean target torque of 20%MVC. High-density surface electromyography recordings from the tibialis anterior muscle were decomposed and the same MUs were tracked across painful (hypertonic saline injection) and non-painful conditions. Torque variability, mean discharge rate (MDR), DR variability (DRvar), RT and the delay between the cumulative spike train and the resultant torque output (neuromechanical delay, NMD) were assessed. The average RT was greater at faster contraction velocities (p=0.01) but was not affected by pain. At the fastest contraction speed, torque variability and DRvar were reduced (p<0.05) and MDR was maintained. Conversely, MDR decreased and DRvar and NMD increased significantly during pain at slow contraction speeds (p<0.05). These results show that reductions in contraction amplitude and increased recruitment of higher threshold MUs at fast contraction speeds appears to compensate for the inhibitory effect of nociceptive inputs on lower threshold MUs, allowing the exertion of fast submaximal contractions during pain.</p
Prefazione [a: Michail Kuzmin, Le stagioni dell'amore, Bari, Stilo, 2020, 172 pp.]
No full text"Kuranty ljubvi" (Le stagioni dell'amore) è un piccolo, ma poeticamente significativo, contributo alla produzione letteraria del Simbolismo russo nel segno della sintesi delle arti. Michail Kuzmin, uno dei più importanti scrittori di quell'epoca, è l'autore del ciclo poetico-musicale e delle partiture."Kuranty ljubvi" (The seasons of love) is a small but poetically significant contribution to the literary production of Russian Symbolism in the context of the synthesis of the arts. Michail Kuzmin, one of the most important writers of that era, is the author of the poetic-musical cycle and of the scores
Dei delitti e delle pene nella traduzione di Michail M. Scerbatov
No full textAfter more than two centuries, this work presents the Russian version of “Dei delitti e delle pene” by Cesare Beccaria, translated by Prince Michail M. Šcerbatov. The edition, conducted on the autographed manuscript, is presented with the original Italian text. In the introductory study, the author traces the fundamental stages of the diffusion of Beccaria’s work in Russia, focusing in particular on the figure of Michail M. Isaev, scholar and translator of the masterpiece by Beccaria, who was the first to re-propose the modern organisation of the “Fifth” edition. The author gives an account of the version proposed by Šcerbatov, investigating its textual genesis and evaluating some aspects of the language used by the translator - first of all the lexicon used for the rendering of philosophical-political and legal terms
Control of trunk muscle force in individuals with low back pain: new insights revealed by high-density surface electromyography
No full textLow back pain (LBP) is a leading cause of disability worldwide, with chronic non-specific LBP (CLBP) accounting for most cases. It is well-recognised that individuals with LBP exhibit different movement patterns compared to those without pain. Extensive research has examined motor adaptations in individuals with CLBP, highlighting alterations in trunk muscle strength, muscle activity, movement patterns, and proprioceptive acuity. Recent studies have also shown that musculoskeletal pain, including CLBP, can impair muscle force control. However, the concept of force or torque steadiness as a motor adaptation in people with CLBP has been relatively understudied and therefore requires further investigation. This thesis presents research that focuses on enhancing our understanding of motor adaptations in people with CLBP, specifically in relation to changes in the control of trunk muscle force/torque steadiness and the potential underlying neuromuscular mechanisms. To achieve this, it examines the relationship between trunk high-density electromyography (HDsEMG) signals and torque using cross-correlation and coherence analyses, and principal component analysis (PCA) to improve these estimations. The first study examined the control of trunk muscle force and EMG-torque relationships during isometric trunk extension contractions, revealing that individuals with CLBP have poorer control compared to pain-free individuals. People with CLBP performed the contractions with altered recruitment strategies, including a higher contribution of more cranial regions of the lumbar erector spinae (ES) to the resultant torque and a failure to increase the contribution of the lumbar ES to the resultant torque with an increase in load. The second study extended these findings to dynamic trunk flexion/extension concentric and eccentric contractions, showing that the control of trunk muscle force is also impaired during these movements alongside altered recruitment patterns. These involved a higher contribution of the thoracolumbar ES to torque, as observed in the first study during trunk extension contractions, and increased abdominal muscle activity, with the centre of activation being more cranial and a higher contribution of this musculature to the resultant torque (particularly the external oblique muscle) during trunk flexion. In contrast, the third study, which investigated the effects of acute low-back soreness induced by delayed onset of muscle soreness (DOMS) on trunk muscle function, recruitment behaviour, movement patterns, and underlying neuromuscular mechanisms, showed that DOMS did not impair trunk force control. However, EMG-torque relationships and kinematics were altered in a contraction-dependent manner. During eccentric contractions, a decrease in the thoracolumbar ES contribution to the resultant torque was observed, and individuals showed increased lumbar flexion during the more demanding contractions. During concentric contractions, a reduction in thoracolumbar range of motion in the sagittal plane was observed, suggesting the maintenance of a more neutral lumbar spine posture, but no alterations in HDsEMG-torque relationships were observed in the presence of DOMS. These findings suggest that pain-free individuals could adapt their motor strategies and maintain muscle performance despite DOMS. The fourth study was a systematic review and meta-analysis that explored the influence of clinical and experimental musculoskeletal pain on the control of muscle force. The findings of this review suggested that the persistent, multidimensional nature of clinical musculoskeletal pain is related to more pronounced impairments in force control compared to the temporary nature of experimental pain, particularly for the trunk. The results of this thesis underscore the importance of evaluating torque steadiness in individuals with CLBP. The findings indicate that people with CLBP exhibit impaired force control and altered trunk muscle recruitment strategies. Future research should explore the value of torque steadiness training and HDsEMG-based biofeedback for enhancing torque steadiness performance in this patient population. These interventions could lead to better-targeted therapies that address the specific neuromuscular deficits associated with CLBP
Bipolar versus high-density surface electromyography for evaluating risk in fatiguing frequency-dependent lifting activities
No full textWorkers often develop low back pain due to manually lifting heavy loads. Instrumental-based assessment tools are used to quantitatively assess the biomechanical risk in lifting activities. This study aims to verify the hypothesis that high-density surface electromyography (HDsEMG) allows an optimized discrimination of risk levels associated with different fatiguing lifting conditions compared to traditional bipolar sEMG. 15 participants performed three lifting tasks with a progressively increasing lifting index (LI) each lasting 15 min. Erector spinae (ES) activity was recorded using both bipolar and HDsEMG systems. The amplitude of both bipolar and HDsEMG can significantly discriminate each pair of LI. HDsEMG data could discriminate across the different LIs starting from the fourth minute of the task while bipolar sEMG could only do so towards the end. The higher discriminative power of HDsEMG data across the lifting tasks makes such methodology a valuable tool to be used to monitor fatigue while lifting and could extend the possibilities offered by currently available instrumental-based tools.</p
Author Correction: Proton irradiation: a key to the challenge of N-glycosidic bond formation in a prebiotic context
No full textInternational audienceThe original version of this Article contained a typographical error in the spelling of the author Mikhail Kapralov, which was incorrectly given as Michail Kapralov. This has now been corrected in the PDF and HTML versions of the Article and in the accompanying Supplementary Information
Hybridity, Identity and Micro-cosmopolitanism in the Ionian 19th century
No full textThe Ionian Islands, a complex of seven islands off the west coast of the Greek peninsula, historically and culturally constitute a contact zone between the Greek-speaking world and the West. In the 19th century, the islands, a former Venetian colony, experienced French and British colonial power before their incorporation in 1864 to the Greek state. This study focuses on the process of transformation of hybrid, cosmopolitan pre-national cultural identities into national schemes of appropriation and affiliation. Here, cultural agents, networking across linguistic, cultural, confessional or other borders, are exemplified by the example of the Lountzis brothers and their special link to the German-speaking world, its philosophy and its poetics. In this study, translation is scrutinised as a field of identity negotiation. It is also understood as a gesture of kinship with larger literary communities in the wider spectrum of the mobility of knowledge and ideas enabled by 19th century mystical sectarianism. The author of this book traces local micro-cosmopolitanism in the form of readership and identity performance, while cosmopolitanism, nationalism and sectarianism are viewed as interacting factors in the transformation of cultural, social and national identities in 19th century Europe.
Michail Leivadiotis, Hybridity, Identity and Micro-cosmopolitanism in the Ionian 19th centur
"Laughing Word" in the Novel by Michail Bulgakov’s "The Mаster and Margarita"
No full textОсновна увага авторів зосереджена на розкритті специфіки комічного в романі М. О. Булгакова «Майстер і Маргарита», на використанні “чужого” слова, а також композиційних прийомів, що спричиняють виникнення комічних ефектів. Діапазон емоційних оцінок, які автор дає своїм комічним персонажам, дуже широкий: від в’їдливої іронії щодо членів літературної асоціації до гумористичних образів звичайних радянських громадян. У статті наведено приклади того, як М. О. Булгаков з нещадною іронією викриває порожнечу й штучність офіційно-канцелярського мовного стандарту, словесних штампів, що приховують справжню, природну сутність явищ. The relevance of the topic of this work is due to the attention of modern philologists to the personal aspect of language learning, to the study of linguistic means that characterize human intentionality; to the dynamic structure of the literary text associated with its existence in the communication “author – reader”. The main attention of the authors is focused on revealing the specifics of the comicality in Bulgakov’s novel «The Master and Margarita», using “someone else’s” words, as well as compositional techniques of representation, leading to comic effects. The range of emotional assessments that the author gives to his comic characters is very wide: from the scathing irony of the literary association memebers to the humorous images of ordinary Soviet citizens. The purpose of this article is to consider what stylistic devices are used by Michail Bulgakov to achieve comic and ironic effects in the novel «The Master and Margarita», creating images of characters. The purpose involves solving the following main tasks: – to consider the main types of comic - humor and irony and their functioning in the novel «The Master and Margarita»; – to identify and consider the basic techniques of organizing a comic text; – to identify and analyze the linguistic means of achieving a comic effect in the text of the novel by Michail Bulgakov. The article provides examples of how Bulgakov with ruthless irony exposes the emptiness and artificiality of the official-clerical language standard, verbal stamps that hide the true, natural essence of phenomena. He seeks to reflect genuine reality, not distorted by the “crooked mirror” of official bureaucratic phrases. The merry magical power of Bulgakov’s laughter is aimed at ridiculing the senseless reality that was idealized by official Soviet literature. There were clear signs of what Bakhtin called the “carnival worldview” and the spirit of ancient menippeiа in «The Master and Margarita»
Figs. 11–13. Heteroborips seriatus, habitus. 11 in Resurrection of Heteroborips Reitter, 1913 (Coleoptera: Curculionidae: Scolytinae) from Synonymy with Xyleborus Eichhoff, 1864
No full textFigs. 11–13. Heteroborips seriatus, habitus. 11) Female, dorsal view. Photograph from www.zin.ru\Animalia\Coleoptera, Author – Kirill V. Makarov. Used with permission as indicated on website; 12) Male, dorsal view; 13) Male, lateral view. Photographs in Figs. 12 and 13 by Boris Anokhin (ZISP) (Mandelshtam et al. 2018).Published as part of Mandelshtam, Michail Yu., Petrov, Alexander V., Smith, Sarah M. & Cognato, Anthony I., 2019, Resurrection of Heteroborips Reitter, 1913 (Coleoptera: Curculionidae: Scolytinae) from Synonymy with Xyleborus Eichhoff, 1864, pp. 387-394 in The Coleopterists Bulletin 73 (2) on page 392, DOI: 10.1649/0010-065X-73.2.387, http://zenodo.org/record/537214
The discrete and continuous berth allocation problem: models and algorithms
No full textFierce terminal competition and the need to maximize recourses utilization have led marine terminal operators to the development and application of a rich variety of Berth Scheduling Policies (BSPs). Container terminal operators seek for efficient BSPs that will reduce vessels turnaround time, increase port throughput, lead to higher revenues and increased competitiveness of the port, while at the same time keep customer satisfaction at desired levels. Several issues arise when defining the best BSPs for each port operator and the final decision depends on several factors that include the type and function of the port (dedicated or multi-user terminal, transshipment hub etc), the size and location of the port, nearby competition, type of contractual agreement with the vessel carriers etc. Some of these BSPs and issues have to a certain extend been captured by academic research, but still several attributes need to be investigated and included for these models to represent the state of the practice of container terminal operations.
In this dissertation we present new models and solution algorithms that portray different BSPs and attempt to capture the operational environment of a container terminal, while at the same time including attributes of the system that current models lack. The formulations and solutions of mathematical models presented herein, seek to optimally schedule vessels and/or quay cranes to berths in multi-user type of container terminals, without losing its applicability to the private type container terminals. The objective is to present models and algorithms that capture as much as possible of current container terminal operator practices, while minimizing the assumptions made about real world conditions that container terminals operate in.Ph.D.Includes bibliographical references (p. 194-200)
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