Deformation Analyses in Cell and Developmental Biology. Part II—Mechanical Experiments on Cells

1987 ◽  
Vol 109 (1) ◽  
pp. 18-24 ◽  
Author(s):  
L. Y. Cheng
Keyword(s):  
Incompressible Material ◽  
Cell Cortex ◽  
Analysis Method ◽  
Membrane Structures ◽  
Approximate Methods ◽  
Contact Algorithm ◽  
Property Data ◽  
A Cell ◽  
Element Approach

This study employs the finite element approach developed in Part I to analyze mechanical experiments on cells. It views cells as axisymmetric membrane structures containing a body of incompressible material, and models the mechanical contact between a cell and the loading apparatus by a contact algorithm. Since the method is valid for analyzing axisymmetric shell-like bodies with arbitrary shapes, it treates various mechanical experiments on cells in a unified manner. For demonstration purposes, three commonly used mechanical experiments on cells are considered; (1) the compression experiment; (2) the suction (micropipette aspiration) experiment; and (3) the magnetic particle experiment. Based on an estimate of the mechanical property data for unfertilized sea urchin eggs, this analysis method predicts the responses for all three experiments using the same assumptions and approximations. This parallel treatment gives a broad basis for data correlation with experiments. The method also provides insights into mechanical experiments not offered by other approximate methods. For example, it gives the distributions of tensions and stretches on the cell cortex, and suggests the role of friction in the suction experiment.

The effects of the shape of tooth profile modifications on the transmission error, bending, and contact stress of spur gears

2010 ◽  
Vol 224 (8) ◽  
pp. 1749-1758 ◽  
Author(s):  
Y A Tesfahunegn ◽  
F Rosa ◽  
C Gorla
Keyword(s):  
Transmission Error ◽  
General Purpose ◽  
Spur Gears ◽  
Good Efficiency ◽  
Contact Algorithm ◽  
Non Linear ◽  
Bending Stresses ◽  
Element Approach ◽  
Tooth Flank

Nowadays, the basic requirements of gear transmissions are not limited to resistance and reliability, but often include good efficiency and low vibration and noise emissions. This article investigates the role of tooth flank micro-geometry in fulfilling these needs. A non-linear finite element approach has been conceived and exploited to investigate in detail the influence of the shape of profile modifications (PMs) on transmission error, root stress, and contact pressure. In this approach, the contact between teeth flanks is handled by ABAQUS general purpose contact algorithm without introducing any simplification based on gear geometry peculiarities. The boundary conditions are defined so that it is possible to automatically run a sequence of static analyses. The numerical results are first assessed by comparison with experimental measurements and then a comparison of contact and bending stresses of the same gear with long linear and long circular PMs is presented and discussed. The results of these comparisons show that the optimal amount of PMs is not independent of PM shape; hence, the procedures used to design linear PMs cannot be directly applied to the design of non-linear PMs.

Centrosome Aurora A gradient ensures single polarity axis in C. elegans embryos

2020 ◽  
Vol 48 (3) ◽  
pp. 1243-1253 ◽  
Author(s):  
Sukriti Kapoor ◽  
Sachin Kotak
Keyword(s):  
Symmetry Breaking ◽  
Cell Fate ◽  
Cell Cortex ◽  
Axis Formation ◽  
Aurora A Kinase ◽  
Aurora A ◽  
C Elegans ◽  
Cell Embryo ◽  
Polarity Establishment

Cellular asymmetries are vital for generating cell fate diversity during development and in stem cells. In the newly fertilized Caenorhabditis elegans embryo, centrosomes are responsible for polarity establishment, i.e. anterior–posterior body axis formation. The signal for polarity originates from the centrosomes and is transmitted to the cell cortex, where it disassembles the actomyosin network. This event leads to symmetry breaking and the establishment of distinct domains of evolutionarily conserved PAR proteins. However, the identity of an essential component that localizes to the centrosomes and promotes symmetry breaking was unknown. Recent work has uncovered that the loss of Aurora A kinase (AIR-1 in C. elegans and hereafter referred to as Aurora A) in the one-cell embryo disrupts stereotypical actomyosin-based cortical flows that occur at the time of polarity establishment. This misregulation of actomyosin flow dynamics results in the occurrence of two polarity axes. Notably, the role of Aurora A in ensuring a single polarity axis is independent of its well-established function in centrosome maturation. The mechanism by which Aurora A directs symmetry breaking is likely through direct regulation of Rho-dependent contractility. In this mini-review, we will discuss the unconventional role of Aurora A kinase in polarity establishment in C. elegans embryos and propose a refined model of centrosome-dependent symmetry breaking.

The Role of Muslim Women in Civil Society In Promoting Values and Principles for Building Peace: Action Guide from The Qur’ān

Sains Insani ◽  
2019 ◽  
Vol 4 (1) ◽  
pp. 30-36
Author(s):  
Che Amnah Bahari ◽  
Fatimah Abdullah
Keyword(s):  
Civil Society ◽  
Lifelong Learning ◽  
Significant Role ◽  
Textual Analysis ◽  
Muslim Women ◽  
Peace Building ◽  
Analysis Method ◽  
Pluralistic Society ◽  
Women And Children

The whole world, the Muslim in particular has witnessed conflicts in different areas, which have hindered the developmental efforts of the nations concerned. It should be learned that most victims of these conflicts are women and children. This article attempts to elaborate the role of Muslims Women as a crucial segment in civil society in initiating peace building through nurturing process. It maintains that the adoption of the principles and values derived from the Qur’ān and Sunnah of the Prophet is necessary as a process of lifelong learning.  Those identified values constituted the framework of this article and it adopts the textual analysis method.   This article concludes that through the implementation of those values and frameworks for peace building, women as one of the important segments of civil society are able to play significant role towards initiating peace building and promoting peaceful co-existence in pluralistic society. Abstrak: Dunia Islam khususnya telah menyaksikan konflik di pelbagai daerah yang berbeza. Konflik ini telah menghalang usaha kearah pembangunan Kawasan yang berkenaan. Kebanyakan mangsa konflik ini adalah wanita dan kanak-kanak. Artikel ini cuba untuk menghuraikan peranan wanita Islam sebagai segmen penting dalam masyarakat madani dalam membangun proses kedamaian dengan mendidik dan memupuk prinsip dan nilai murni janaan al-Qur’an. Penggunaan prinsip dan nilai yang dikutip dari ayat-ayat Qur'an dan hadis Rasulullah adalah keperluan yang mendesak sebagai wadah bagi proses pembelajaran sepanjang hayat. Nilai-nilai yang dikenal pasti merupakan rangka kerja artikel ini, dan metod yang dirujuk adalah analisis teks. Artikel ini menyimpulkan bahawa melalui pelaksanaan nilai-nilai dan kerangka kerja Islam bagi proses kedamaian, wanita Islam dalam masyarakat madani mampu memainkan peranan penting dalam memulakan pembinaan keamanan dan menggalakkan kehidupan yang harmonis, sejahtera dan saling bantu membantu dalam masyarakat majmuk.

CD38 as an immunomodulator in cancer

2020 ◽  
Vol 16 (34) ◽  
pp. 2853-2861
Author(s):  
Yanli Li ◽  
Rui Yang ◽  
Limo Chen ◽  
Sufang Wu
Keyword(s):  
Multiple Myeloma ◽  
Cell Activation ◽  
Human Tissues ◽  
Transmembrane Glycoprotein ◽  
Cell Activation Marker ◽  
Research Findings ◽  
A Cell ◽  
And Function ◽  
Human Molecule

CD38 is a transmembrane glycoprotein that is widely expressed in a variety of human tissues and cells, especially those in the immune system. CD38 protein was previously considered as a cell activation marker, and today monoclonal antibodies targeting CD38 have witnessed great achievements in multiple myeloma and promoted researchers to conduct research on other tumors. In this review, we provide a wide-ranging review of the biology and function of the human molecule outside the field of myeloma. We focus mainly on current research findings to summarize and update the findings gathered from diverse areas of study. Based on these findings, we attempt to extend the role of CD38 in the context of therapy of solid tumors and expand the role of the molecule from a simple marker to an immunomodulator.

scholarly journals PapRIV, a BV-2 microglial cell activating quorum sensing peptide

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yorick Janssens ◽  
Nathan Debunne ◽  
Anton De Spiegeleer ◽  
Evelien Wynendaele ◽  
Marta Planas ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Cell Model ◽  
Dependent Manner ◽  
Communication Signals ◽  
Gram Positive Bacteria ◽  
A Cell ◽  
Gastro Intestinal Tract

AbstractQuorum sensing peptides (QSPs) are bacterial peptides produced by Gram-positive bacteria to communicate with their peers in a cell-density dependent manner. These peptides do not only act as interbacterial communication signals, but can also have effects on the host. Compelling evidence demonstrates the presence of a gut-brain axis and more specifically, the role of the gut microbiota in microglial functioning. The aim of this study is to investigate microglial activating properties of a selected QSP (PapRIV) which is produced by Bacillus cereus species. PapRIV showed in vitro activating properties of BV-2 microglia cells and was able to cross the in vitro Caco-2 cell model and reach the brain. In vivo peptide presence was also demonstrated in mouse plasma. The peptide caused induction of IL-6, TNFα and ROS expression and increased the fraction of ameboid BV-2 microglia cells in an NF-κB dependent manner. Different metabolites were identified in serum, of which the main metabolite still remained active. PapRIV is thus able to cross the gastro-intestinal tract and the blood–brain barrier and shows in vitro activating properties in BV-2 microglia cells, hereby indicating a potential role of this quorum sensing peptide in gut-brain interaction.

The “Halalification” of tourism

2017 ◽  
Vol 8 (4) ◽  
pp. 558-577 ◽  
Author(s):  
Faiza Khan ◽  
Michelle Callanan
Keyword(s):  
Design Methodology ◽  
Secondary Data ◽  
Market Segment ◽  
Analysis Method ◽  
Review Of Literature ◽  
Primary Research ◽  
Content Type ◽  
Starting Point ◽  
Practical Implications

Purpose The purpose of this paper is to address the confusing use of terminology associated with tourism undertaken by Muslims and to identify key concerns associated with this type of tourism. Design/methodology/approach This is an exploratory study and adopts a critical review of literature following the evolutionary concept analysis method. Content analysis of popular UK media, UK-based tour operators’ websites and tourism strategies of destinations popular with Muslim tourists were conducted to examine the use of terminology. Findings There is no clear difference between the various terms (halal, Muslim friendly, Islamic, etc.) used. Overall, academia uses the term Islamic tourism, while the industry and media use various terms. Among destinations, however, there is no clear and consistent use of terminology. A key concern of Islamic tourism is the role of certification in assuring travellers and the lack of standardisation of halal certification. Research limitations/implications The paper is based on literature review and secondary data analysis. It lacks primary research. Practical implications This study highlights the need for consistent use of terminology across industry. Another implication is the issue surrounding halal certification of food and the importance of trust in the seller/service provide. Another trend that industry providers need to consider is the growth of the Muslim millennial traveller and the needs of this market segment. Originality/value The paper highlights the importance of studying the Muslim tourist market and provides a starting point for further research. It highlights several issues such as the need to develop a typology of Muslim tourists. Of particular interest is the concern whether halal values in danger of being commodified in the absence of a universal agreed criterion for halal certification.

scholarly journals Corrigendum to ‘Multi-layered bird beaks: a finite-element approach towards the role of keratin in stress dissipation’

2013 ◽  
Vol 10 (78) ◽  
pp. 20120733
Author(s):  
Jorris Soons ◽  
Anthony Herrel ◽  
Annelies Genbrugge ◽  
Dominique Adriaens ◽  
Peter Aerts ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Approach ◽  
Element Approach

PERAN KPU DALAM PENCAPAIAN TARGET PARTISIPASI PEMILIH PADA PEMILIHAN KEPALA DAERAH KABUPATEN KARAWANG TAHUN 2015

2021 ◽  
Vol 12 (1) ◽  
pp. 13-21
Author(s):  
Ahmad Mustopa Kamal ◽  
Ainur Rofieq
Keyword(s):  
Community Participation ◽  
Specific Problem ◽  
Descriptive Analysis ◽  
Voter Participation ◽  
Analysis Method

The background of this research is based on the efforts of the KPU of Karawang Regency in achieving the target of voter participation in the election of the Regional Head of Karawang Regency in 2015, where the KPU targets community participation around 72%. But from the results of the KPU recapitulation in Karawang Regency voter participation reached 67%. This indicates that the target of voter participation from the KPU of Karawang Regency was not achieved in the election of the regional head. This study uses descriptive analysis method to focus on a specific problem in detail. The focus of the research is: KPU's efforts in achieving the target of community participation in the Karawang District Election especially in Cibuaya District, Karawang Regency. The results of this study indicate that in planning achievement of voter participation target in the Karawang regency elections in 2015 Karawang Regency KPU did various things to direct voter participation, especially in terms of planning. Thus the role of the KPU in achieving the target of voter participation in the election of the Regional Head of Karawang Regency in 2015 in the District of Cibuaya has been done well.

scholarly journals A Role for the DnaJ Homologue Scj1p in Protein Folding in the Yeast Endoplasmic Reticulum

1998 ◽  
Vol 143 (4) ◽  
pp. 921-933 ◽  
Author(s):  
Susana Silberstein ◽  
Gabriel Schlenstedt ◽  
Pam A. Silver ◽  
Reid Gilmore
Keyword(s):  
Endoplasmic Reticulum ◽  
Unfolded Protein Response ◽  
Physiological Role ◽  
Carboxypeptidase Y ◽  
Reporter Protein ◽  
Unfolded Protein ◽  
A Cell ◽  
The Unfolded Protein Response ◽  
Protein Response

Members of the eukaryotic heat shock protein 70 family (Hsp70s) are regulated by protein cofactors that contain domains homologous to bacterial DnaJ. Of the three DnaJ homologues in the yeast rough endoplasmic reticulum (RER; Scj1p, Sec63p, and Jem1p), Scj1p is most closely related to DnaJ, hence it is a probable cofactor for Kar2p, the major Hsp70 in the yeast RER. However, the physiological role of Scj1p has remained obscure due to the lack of an obvious defect in Kar2p-mediated pathways in scj1 null mutants. Here, we show that the Δscj1 mutant is hypersensitive to tunicamycin or mutations that reduce N-linked glycosylation of proteins. Although maturation of glycosylated carboxypeptidase Y occurs with wild-type kinetics in Δscj1 cells, the transport rate for an unglycosylated mutant carboxypeptidase Y (CPY) is markedly reduced. Loss of Scj1p induces the unfolded protein response pathway, and results in a cell wall defect when combined with an oligosaccharyltransferase mutation. The combined loss of both Scj1p and Jem1p exaggerates the sensitivity to hypoglycosylation stress, leads to further induction of the unfolded protein response pathway, and drastically delays maturation of an unglycosylated reporter protein in the RER. We propose that the major role for Scj1p is to cooperate with Kar2p to mediate maturation of proteins in the RER lumen.

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