Structure of the human inner kinetochore bound to a centromeric CENP-A nucleosome

Accurate chromosome segregation, controlled by kinetochore-mediated chromatid attachments to the mitotic spindle, ensures the faithful inheritance of genetic information. Kinetochores assemble onto specialized CENP-A nucleosomes (CENP-ANuc) of centromeric chromatin. In humans, this is mostly organized as thousands of copies of an ~171 bp α-satellite repeat. Here, we describe the cryo-EM structure of the human inner kinetochore CCAN (Constitutive Centromere Associated Network) complex bound to CENP-ANuc reconstituted onto α-satellite DNA. CCAN forms edge-on contacts with CENP-ANuc, while a linker DNA segment of the α-satellite repeat emerges from the fully-wrapped end of the nucleosome to thread through the central CENP-LN channel which tightly grips the DNA. The CENP-TWSX histone-fold module, together with CENP-HIKHead, further augments DNA binding and partially wraps the linker DNA in a manner reminiscent of canonical nucleosomes. Our study suggests that the topological entrapment of the α-satellite repeat linker DNA by CCAN provides a robust mechanism by which the kinetochore withstands the pushing and pulling of centromeres associated with chromosome congression and segregation forces.

Validation of an Embedded Motion-Capture and EMG Setup for the Analysis of Musculoskeletal Disorder Risks during Manhole Cover Handling

Musculoskeletal disorders in the workplace are a growing problem in Europe. The measurement of these disorders in a working environment presents multiple limitations concerning equipment and measurement reliability. The aim of this study was to evaluate the use of inertial measurement units against a reference system for their use in the workplace. Ten healthy volunteers conducted three lifting methods (snatching, pushing, and pulling) for manhole cover using a custom-made tool weighting 20 and 30 kg. Participants’ back and dominant arm were equipped with IMU, EMG, and reflective markers for VICON analysis and perception of effort was estimated at each trial using a Visual Analog Scale (VAS). The Bland–Altman method was used and results showed good agreement between IMU and VICON systems for Yaw, Pitch and Roll angles (bias values < 1, −4.4 < LOA < 3.6°). EMG results were compared to VAS results and results showed that both are a valuable means to assess efforts during tasks. This study therefore validates the use of inertial measurement units (IMU) for motion capture and its combination with electromyography (EMG) and a Visual Analogic Scale (VAS) to assess effort for use in real work situations.

Development of a Motorized Hospital Bed with Swerve Drive Modules for Holonomic Mobility

In hospitals; transferring patients using hospital beds is time consuming and inefficient. Additionally; the task of frequently pushing and pulling beds poses physical injury risks to nurses and caregivers. Motorized hospital beds with holonomic mobility have been previously proposed. However; most such beds come with complex drivetrain which makes them costly and hinders larger-scale adoption in hospitals. In this study; a motorized hospital bed that utilizes a swerve drive mechanism is proposed. The design takes into account simplicity which would allow for minimum modification of the existing beds. Two DC motors for steering and propulsion are used for a single swerve drive module. The control of the propulsion motor is achieved by a combination of trajectory planning based on quintic polynomials and PID control. Further; the control performance of the proposed bed was evaluated; and the holonomic mobility of its prototype was successfully demonstrated. An average error of less than 3% was obtained for motion with a constant velocity; however; larger values in the range of 15% were observed for other conditions, such as accelerating and decelerating.

Circular Economy Business Models: The Complementarities with Sharing Economy and Eco-Innovations Investments

The transition from the linear economy to the circular economy exhibits some criticalities that can be solved through the identification of factors pushing and pulling the transition itself. By adopting a public good perspective in analysing the main features of the circular business models, this study underlines how the sharing economy business models are well integrated and complementary to some features of the circular economy, representing a strong pulling factor. Other loops of the circular economy need an explicit push factor, individuated in a strong impulse to eco-efficiency, to be reached through consistent incentives to invest in R&D for eco-innovations. Seven case studies are investigated in their aims, feasibility and implementation to support the interpretative framework.

Alteration in HDEMG Spatial Parameters of Trunk Muscle Due to Handle Design during Pushing

Previous research identifies that pushing and pulling is responsible for approximately 9–18% of all low back injuries. Additionally, the handle design of a cart being pushed can dramatically alter a worker’s capacity to push (≅9.5%). Surprisingly little research has examined muscle activation of the low back and its role in muscle function. Therefore, the purpose of this study was to examine the effects of handle design combination of pushing a platform truck cart on trunk muscle activity. Twenty participants (10 males and 10 females, mean age = 24.3 ± 4.3 years) pushed 475 lbs using six different handle combinations involving handle orientation (vertical/horizontal/semi-pronated) and handle height (hip/shoulder). Multichannel high-density EMG (HDsEMG) was recorded for left and right rectus abdominis, erector spinae, and external obliques. Pushing at hip height with a horizontal handle orientation design (HH) resulted in significantly less (p < 0.05) muscle activity compared to the majority of other handle designs, as well as a significantly higher entropy than the shoulder handle height involving either the semi-pronated (p = 0.023) or vertical handle orientation (p = 0.028). The current research suggests that the combination of a hip height and horizontal orientation handle design may require increased muscle demand of the trunk and alter the overall muscle heterogeneity and pattern of the muscle activity.

From Precariousness to Prudence: Eco-Cosmopolitanism as the Fabric for Weaving the Post-COVID World

In a crucial juncture when the whole world has been shattered by the reign of a tiny virus invading the apparently invincible empire of human ‘civilization’, the plaguing pandemic has brought to the fore fundamentally interconnected nature of our collective existence and consequently our shared vulnerability. COVID-19 as essentially a zoonotic disease accentuates the anthropogenic hazards inflicted on the ecosystem resulting in spilling over of such pathogens from animals to humans. It also nudges us to reflect on our fundamentally interconnected existence which we have long remained oblivious about. The prevailing obliviousness seems to have emanated from willful ignorance or selfdeceptive knowledge rooted in over-arching dictates of anthropocentrism; however on the structural front, the roots can be traced back to the capitalistic system perpetuating the ‘homo economicus’ aspirations so as to mark the unflinching triumph of the ‘Capitalocene’. While pushing and pulling ourselves to adapt to the ‘new normal’, it becomes an imperative to go beyond the myopic vision of restricting ourselves to shortterm mitigation measures like border-closure or vaccination; instead time is ripe for taking a critical and broad-based stance on the structural roots of the current pandemic such that restructuration of post-COVID world helps shoving aside such calamitous disaster in days to come. It is in this regard, a radical take on ‘cosmopolitanism’ seems the need of the hour to fill the lacunae in the existing mode of perusing interconnectedness that operates only on the surface level in the name of ‘globalization’ and overlooks the fundamental rubric of ecological integrity. While shedding some light on the nexus that this pandemic shares with the evils of capitalistic enterprise and neoliberal culture of globalized consumerism, this paper, within its limited scope, will make an attempt to find an antidote to the current crisis through endorsing an ‘eco-cosmopolitan’ worldview wherein the rationalized ‘instrumentalization’ of environment and wild animals gets overridden by an eco-centric perspective on our fundamentally interconnected existence.

The pattern of force produced during approach-avoidance movements is independent of emotional valence

Movements that include pushing away and pulling towards oneself are important avoidance and approach behaviors, respectively. Previous research has demonstrated that reaction times are more rapid when approach-like movements are undertaken in response to pleasant emotional stimuli and when avoidant movements are carried out in response to unpleasant emotional stimuli. However, few studies have directly investigated the forces applied during self-referenced approach or avoidance movements. Here we measured the sustained forces of pushing and pulling in response to emotional images. The images presented varied in ratings of emotional arousal (i.e., relaxing versus exciting) and valence (positive valence, or pleasant, versus negative valence, or unpleasant). Our results replicate previous findings that documented force produced in response to unpleasant images. Our findings also revealed that, in contrast to their impact on reaction times, the effects of emotional stimuli on the sustained forces associated with approach and avoidance responses are independent of the direction of movement.

Mechanisms for Chromosome Segregation in Bacteria

The process of DNA segregation, the redistribution of newly replicated genomic material to daughter cells, is a crucial step in the life cycle of all living systems. Here, we review DNA segregation in bacteria which evolved a variety of mechanisms for partitioning newly replicated DNA. Bacterial species such as Caulobacter crescentus and Bacillus subtilis contain pushing and pulling mechanisms that exert forces and directionality to mediate the moving of newly synthesized chromosomes to the bacterial poles. Other bacteria such as Escherichia coli lack such active segregation systems, yet exhibit a spontaneous de-mixing of chromosomes due to entropic forces as DNA is being replicated under the confinement of the cell wall. Furthermore, we present a synopsis of the main players that contribute to prokaryotic genome segregation. We finish with emphasizing the importance of bottom-up approaches for the investigation of the various factors that contribute to genome segregation.