scholarly journals Coexistence of Two Chiral Helices Produces Kink Translation in Spiroplasma Swimming

2020 ◽  
Vol 202 (8) ◽  
Author(s):  
Daisuke Nakane ◽  
Tatsuro Ito ◽  
Takayuki Nishizaka
Keyword(s):  
Cell Body ◽  
The Body ◽  
Structural Basis ◽  
Helical Structures ◽  
Content Type ◽  
Carbonyl Cyanide ◽  
Rotary Motors ◽  
Propulsion Force ◽  
Swimming Bacteria ◽  
The Right

ABSTRACT The mechanism underlying Spiroplasma swimming is an enigma. This small bacterium possesses two helical shapes with opposite-handedness at a time, and the boundary between them, called a kink, travels down, possibly accompanying the dual rotations of these physically connected helical structures, without any rotary motors such as flagella. Although the outline of dynamics and structural basis has been proposed, the underlying cause to explain the kink translation is missing. We here demonstrated that the cell morphology of Spiroplasma eriocheiris was fixed at the right-handed helix after motility was stopped by the addition of carbonyl cyanide 3-chlorophenylhydrazone (CCCP), and the preferential state was transformed to the other-handedness by the trigger of light irradiation. This process coupled with the generation and propagation of the artificial kink, presumably without any energy input through biological motors. These findings indicate that the coexistence of two chiral helices is sufficient to propagate the kink and thus to propel the cell body. IMPORTANCE Many swimming bacteria generate a propulsion force by rotating helical filaments like a propeller. However, the nonflagellated bacteria Spiroplasma spp. swim without the use of the appendages. The tiny wall-less bacteria possess two chiral helices at a time, and the boundary called a kink travels down, possibly accompanying the dual rotations of the helices. To solve this enigma, we developed an assay to determine the handedness of the body helices at the single-wind level, and demonstrated that the coexistence of body helices triggers the translation of the kink and that the cell body moves by the resultant cell bend propagation. This finding provides us a totally new aspect of bacterial motility, where the body functions as a transformable screw to propel itself forward.

Demonstration of the relationship between MSD and online learning during the COVID-19 pandemic

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kochu Therisa Karingada ◽  
Michael Sony
Keyword(s):  
Online Learning ◽  
Undergraduate Students ◽  
Online Survey ◽  
Cross Sectional Study ◽  
The Body ◽  
Body Parts ◽  
Cross Sectional ◽  
Content Type ◽  
The Right ◽  
Almost All

PurposeThe COVID-19 pandemic lockdown has caught many educational institutions by surprise and warranted an abrupt migration from offline to online learning. This has resulted in an education change, without any time for due consideration, as regards its impact on musculoskeletal disorders (MSD) on students. The purpose of this study is to investigate MSD related to online learning during the COVID-19 pandemic lockdown.Design/methodology/approachA cross-sectional study was conducted on undergraduate students in India. In total, 261 students participated in this online survey.FindingsThe study finds that around 80% of students have reported some symptom in the head, neck and eyes since they started online learning. In total, 58% have reported MSD symptom in the right shoulder and 56% in the right hand fingers. Besides, more than 40 % of students experienced some MSD symptoms, in almost all the body parts studied, due to online learning. Correlation analysis is conducted between time spent on online learning per day and MSD symptoms.Originality/valueThis is the first study conducted on MSD and online learning during COVID-19 pandemic.

Working effectively and living contentedly in a foreign country: what human capital do expatriates require and develop?

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Reimara Valk
Keyword(s):  
Human Capital ◽  
Foreign Country ◽  
The Body ◽  
Future Research ◽  
Global Business ◽  
Line Managers ◽  
Content Type ◽  
Human Capital Model ◽  
Hr Managers ◽  
The Right

PurposeThe purpose of this paper is to explore the human capital (HC) expatriates require and develop during an international assignment (IA) to work effectively and live contentedly in a host country.Design/methodology/approachQualitative research entailing interviews with 78 expatriates and repatriates across the globe, investigating the competencies they developed and the HC they gained during their IAs.FindingsFive interrelated competence clusters were derived: cultural competence (CC); interpersonal competence; intrapersonal competence; global business competence; global leadership competence, each containing competencies crucial for expatriate success.Research limitations/implicationsThis study relied on self-reports by expatriates and repatriates. Future research should also include senior/line managers and chief human resource officers from a range of organizations across the world to gather their assessments on the competencies and HC of expatriates and repatriates.Practical implicationsLine/HR managers can use the designed “Expatriate/Repatriate Human Capital model” to assess an individual's overall readiness and capacity to perform effectively in a foreign country and culture and consecutively identify and select the right candidates to undertake IAs.Originality/valueThis paper contributes to the literature by presenting a HC model called the “Expatriate and Repatriate Human Capital Model; the body of competence”. The model identifies and defines the competencies/knowledge, skills, abilities and other characteristics (KSAOs) required for intercultural effectiveness and expatriate success and serves as a tool for the selection, training, development and performance evaluation of expatriates and repatriates, in order to aid the accomplishment of individual and organizational objectives.

Investigation into effects of cooling rate on properties of polyamide 12 parts in the multi jet fusion process

2020 ◽  
Vol 26 (10) ◽  
pp. 1789-1795
Author(s):  
Mattia Mele ◽  
Giampaolo Campana ◽  
Gregorio Pisaneschi ◽  
Gian Luca Monti
Keyword(s):  
Cooling Rate ◽  
Three Dimensional ◽  
The Body ◽  
Scanning Calorimetry ◽  
Content Type ◽  
Polyamide 12 ◽  
Body Of Knowledge ◽  
Cooling Phase ◽  
The Right ◽  
High Building

Purpose Multi jet fusion is an industrial additive manufacturing technology characterised by high building speed and considerable properties of the parts. The cooling phase represents a crucial step to determine productivity, since it can take up to 4.5 times the building time. The purpose of this paper is to investigate into effects of cooling rate on parts manufactured by multi jet fusion. Crystallinity, density, distortions and mechanical properties of specimens produced through an HP multi jet fusion 4200 are examined. Design/methodology/approach An experimental activity is carried out on specimens cooled down at three different rates. Properties of the parts are analysed by means of differential scanning calorimetry, optical microscopy, three-dimensional scanning and tensile testing. Originality/value The present work makes a contribution to the body of knowledge providing correlations between the cooling phase of multi jet fusion and part properties. These results can be used to choose the right balance between production time and product quality.

scholarly journals Gliding Direction of Mycoplasma mobile

2015 ◽  
Vol 198 (2) ◽  
pp. 283-290 ◽  
Author(s):  
Hanako Morio ◽  
Taishi Kasai ◽  
Makoto Miyata
Keyword(s):  
Solid Surface ◽  
Thermal Fluctuation ◽  
Solid Surfaces ◽  
Cell Axis ◽  
Content Type ◽  
Propulsion Force ◽  
A Cell ◽  
The Right ◽  
Triton X ◽  
Unique Mechanism

ABSTRACTMycoplasma mobileglides in the direction of its cell pole by a unique mechanism in which hundreds of legs, each protruding from its own gliding unit, catch, pull, and release sialylated oligosaccharides fixed on a solid surface. In this study, we found that 77% of cells glided to the left with a change in direction of 8.4° ± 17.6° μm−1displacement. The cell body did not roll around the cell axis, and elongated, thinner cells also glided while tracing a curved trajectory to the left. Under viscous conditions, the range of deviation of the gliding direction decreased. In the presence of 250 μM free sialyllactose, in which the binding of the legs (i.e., the catching of sialylated oligosaccharides) was reduced, 70% and 30% of cells glided to the left and the right, respectively, with changes in direction of ∼30° μm−1. The gliding ghosts, in which a cell was permeabilized by Triton X-100 and reactivated by ATP, glided more straightly. These results can be explained by the following assumptions based on the suggested gliding machinery and mechanism: (i) the units of gliding machinery may be aligned helically around the cell, (ii) the legs extend via the process of thermal fluctuation and catch the sialylated oligosaccharides, and (iii) the legs generate a propulsion force that is tilted from the cell axis to the left in 70% and to the right in 30% of cells.IMPORTANCEMycoplasmas are bacteria that are generally parasitic to animals and plants. SomeMycoplasmaspecies form a protrusion at a pole, bind to solid surfaces, and glide. Although these species appear to consistently glide in the direction of the protrusion, their exact gliding direction has not been examined. This study analyzed the gliding direction in detail under various conditions and, based on the results, suggested features of the machinery and the mechanism of gliding.

Effects of clothing ease and body postures on the air gap and clothing coverage

2019 ◽  
Vol 31 (4) ◽  
pp. 578-594
Author(s):  
Shitan Wang ◽  
Xiuhua Wang ◽  
Yunyi Wang
Keyword(s):  
Air Gap ◽  
The Body ◽  
Upper Body ◽  
Gap Size ◽  
Lower Body ◽  
Content Type ◽  
Body Postures ◽  
Body Regions ◽  
Gap Models ◽  
The Right

Purpose The purpose of this paper is to determine the effects of clothing ease and body postures on the size and distribution of the air gap as well as the body coverage with the clothing. Design/methodology/approach Visual and quantitative analyses were conducted using a 3D body scanner and Geomagic Software. The air gap size and clothing area factor (fcl) in three test coverall and seven selected postures were calculated and compared. Findings The results indicated that both the clothing ease and body postures had a strong effect on the air gap and clothing coverage, especially the more complex the postures, the wider the range of influence. Nevertheless, these effects varied over body regions, being stronger at the lower body than the upper body. The air gap size at the left side of the body was generally larger than the right side. It was also found that the clothing coverage was linearly correlated with the air gap size and could be employed as an indicator to evaluate clothing protective capabilities. Practical implications The findings suggested that greater attention should be paid to the protection and flexibility at the lower body and asymmetrical distribution of the air gap should be considered in the future air gap modeling. Originality/value The outcomes provided useful information to improve the protective clothing and develop more realistic air gap models to simulate the heat and mass transfer.

Multiple giant hydatid cysts of the brain

1982 ◽  
Vol 57 (3) ◽  
pp. 413-415 ◽  
Author(s):  
Ajay Sharma ◽  
Jacob Abraham
Keyword(s):  
Computerized Tomography ◽  
Hydatid Disease ◽  
Rare Case ◽  
The Body ◽  
Hydatid Cysts ◽  
Content Type ◽  
Multiple Primary ◽  
The Right ◽  
The Brain ◽  
Fine Print

✓ A rare case of multiple primary hydatid cysts of the brain is reported in a 9-year-old girl. There were five cysts, occupying most of the right supratentorial region. The biggest cyst measured 9 cm across, while the smallest one was 4.5 cm in diameter. The diagnosis was based on computerized tomography findings. The patient did not have any evidence of hydatid disease elsewhere in the body. The delivery of all the cysts resulted in the dramatic neurological recovery of this patient.

An anatomical study of the C-2 pedicle

2004 ◽  
Vol 1 (3) ◽  
pp. 306-310 ◽  
Author(s):  
Sait Naderi ◽  
Candan Arman ◽  
Mustafa Güvençer ◽  
Esin Korman ◽  
Mehmet ŞsenoğLu ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Posterior Part ◽  
The Body ◽  
Lateral Mass ◽  
Content Type ◽  
Articular Process ◽  
Inferior Aspect ◽  
Pars Interarticularis ◽  
The Right ◽  
Fine Print

Object. The C-2 pedicle plays an important role regarding screw purchase for spinal fixation. The aim of this study was to measure the C-2 pedicle—related linear and angular parameters. Methods. Seven parameters in 160 C-2 pedicles (80 dry vertebrae) were measured using a Vernier caliper (accurate to 0.1 mm) and goniometer. The Student t-test was used to determine statistical significance. The authors found that the C-2 isthmus (pars interarticularis) and the C-2 pedicle are distinct structures. The C-2 isthmus covers the pedicle. The isthmus is present between the superior and inferior articular processes, and the pedicle is the structure beneath the C-2 isthmus. It connects the lateral mass—inferior articular process to the body of the axis. The heights of the right and the left C-2 pediculoisthmic components (PICs) were 10.3 ± 1.6 and 9.9 ± 1.5 mm, respectively. The posterior part of the superior aspect of the PIC was wider than the anterior portion. The widths of the posterosuperior aspect of the PIC were 11.1 ± 2 and 11 ± 1.7 mm on the right and left sides, whereas the widths of the anterosuperior aspect of the PIC were 7.9 ± 1.7 and 8.5 ± 1.6 mm, respectively. The inferior widths of this component were 6.0 ± 1.5 and 5.5 ± 1.3 mm on the right and left side, respectively. The lengths of the component were 28.8 ± 2.9 mm on the right and 28.8 ± 3.4 mm on the left side. The PIC exhibits a lateral-to-medial and an inferior-to-superior angle. Its axial angles were 28.4 ± 2.5 and 28.6 ± 2.2° on the right and left sides, respectively; its sagittal angles were 18.8 ± 2.1 and 18.8 ± 1.7°, respectively. Conclusions. The C-2 pedicle can be seen in the inferior aspect of the vertebra, and it connects posterior vertebral elements (that is, the lateral mass and inferior articular process) to the axial body. The isthmus drapes the pedicle. The authors suggest that this be termed “the pediculoisthmic component.”

Impact of sustainability strategies on small- and medium-sized enterprises in Zimbabwe

2020 ◽  
Vol 16 (2) ◽  
pp. 149-163
Author(s):  
Donnemore Majukwa ◽  
Susan K. Fan ◽  
Rocky J. Dwyer
Keyword(s):  
Developing Economies ◽  
The Body ◽  
Business Practices ◽  
Growth Strategies ◽  
Structured Interviews ◽  
Content Type ◽  
Job Opportunities ◽  
Sustainability Strategies ◽  
Quality Of Products ◽  
The Right

PurposeThis qualitative multiple-case study aims to explore strategies that owners of small- and medium-sized enterprises (SMEs) in Zimbabwe use to sustain their businesses.Design/methodology/approachThe participants of this study consisted of owners of SMEs purposefully selected who were successful in implementing sustainable strategies for over five years. Semi-structured interviews were conducted with each participant to gain a deeper understanding of their experience in implementing sustainable strategies for SMEs. The general systems theory, which specifies the relationship and interaction of a system and its environment, was applied as a framework to explain the sustainability strategies for SMEs in Zimbabwe.FindingsFour major themes emerged from data analysis: passion and dedication, quality of products and services, customer satisfaction and employing staff with the right skills.Practical implicationsThis study may lead owners of SMEs to create growth strategies for their businesses, increase revenue for the country and create long-term job opportunities for the communities.Originality/valueThe findings from the study addressed the gap on the existing literature and contribute to the body of knowledge on effective business practices, particularly for SMEs in Zimbabwe and other developing economies. The results of the study could catalyze a positive social change by improving workforce capabilities, creating awareness of the success of entrepreneurs in Zimbabwe and increasing the interest of financial institutions in lending to SMEs.

SpaceX Hyperloop: a future technology disruption of the transportation system?

foresight ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wesley L. Harris ◽  
Jarunee Wonglimpiyarat
Keyword(s):  
Past Research ◽  
The Body ◽  
Transportation Industry ◽  
Content Type ◽  
Future Technology ◽  
Factors Influencing ◽  
The Future ◽  
Paradigmatic Change ◽  
Classical Economic ◽  
The Right

Purpose This paper aims to discuss the possibility that Hyperloop using air levitation technology would create a revolution in the future industry of transportation. It also analyses the financing dimension in bringing Hyperloop technology towards full-scale commercialisation. Design/methodology/approach The study uses a case study of SpaceX Hyperloop. The analyses if Hyperloop would bring about a paradigmatic shift in the transportation industry are based on the classical economic theories of technology S-curves (Utterback and Abernathy, 1975; Fisher and Pry, 1971) and Schumpeter’s model of economic development (Schumpeter, 1939, 1967). The three factors influencing a paradigmatic change (a shift in technoeconomic paradigm) according to Freeman and Perez (1988) are also explored. Findings The analyses of findings have shown that Hyperloop has not yet met three factors influencing a paradigmatic change. However, the Hyperloop technology has the potential to create a new market of mass transportation. In terms of technology financing, SpaceX needs the right financing infrastructure – corporate venture arm, the crowdfunding platform, initial coin offering, as well as debt and equity financing to accelerate the process of commercialisation. As the project moves forward, Hyperloop technology would create a market for itself (innovation to create the demand and not demand to create innovation).v Originality/value Although the body of literature on technology management is already voluminous, there has been a scarcity of past research devoted to elucidating the technology disruption and technology financing. This research study has applied the concepts of technology S-curves to better understand if SpaceX Hyperloop would bring about a paradigm shift or revolution in the future of the transportation industry. The research findings would help fill an identified knowledge gap in the body of research in technology disruption and financing.

Our Bodies, Whose Property?

2013 ◽  
Author(s):  
Anne Phillips
Keyword(s):  
Labor Markets ◽  
Personal Autonomy ◽  
The Body ◽  
Body Parts ◽  
Complex Issue ◽  
Human Organs ◽  
Property Owners ◽  
The Common ◽  
The Difference ◽  
The Right

No one wants to be treated like an object, regarded as an item of property, or put up for sale. Yet many people frame personal autonomy in terms of self-ownership, representing themselves as property owners with the right to do as they wish with their bodies. Others do not use the language of property, but are similarly insistent on the rights of free individuals to decide for themselves whether to engage in commercial transactions for sex, reproduction, or organ sales. Drawing on analyses of rape, surrogacy, and markets in human organs, this book challenges notions of freedom based on ownership of our bodies and argues against the normalization of markets in bodily services and parts. The book explores the risks associated with metaphors of property and the reasons why the commodification of the body remains problematic. The book asks what is wrong with thinking of oneself as the owner of one's body? What is wrong with making our bodies available for rent or sale? What, if anything, is the difference between markets in sex, reproduction, or human body parts, and the other markets we commonly applaud? The book contends that body markets occupy the outer edges of a continuum that is, in some way, a feature of all labor markets. But it also emphasizes that we all have bodies, and considers the implications of this otherwise banal fact for equality. Bodies remind us of shared vulnerability, alerting us to the common experience of living as embodied beings in the same world. Examining the complex issue of body exceptionalism, the book demonstrates that treating the body as property makes human equality harder to comprehend.

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