Zeitschriftenartikel: „Bacterial mechanosensing“

1

Chawla, Ravi, Rachit Gupta, Tanmay P. Lele und Pushkar P. Lele. „A Skeptic's Guide to Bacterial Mechanosensing“. Journal of Molecular Biology 432, Nr. 2 (Januar 2020): 523–33. http://dx.doi.org/10.1016/j.jmb.2019.09.004.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

2

Tala, Lorenzo, Xavier Pierrat und Alexandre Persat. „Bacterial Mechanosensing with Type IV Pili“. Biophysical Journal 114, Nr. 3 (Februar 2018): 3a. http://dx.doi.org/10.1016/j.bpj.2017.11.045.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

3

Lele, P. P., B. G. Hosu und H. C. Berg. „Dynamics of mechanosensing in the bacterial flagellar motor“. Proceedings of the National Academy of Sciences 110, Nr. 29 (01.07.2013): 11839–44. http://dx.doi.org/10.1073/pnas.1305885110.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

4

Straub, Hervé, Claudio M. Bigger, Jules Valentin, Dominik Abt, Xiao‐Hua Qin, Leo Eberl, Katharina Maniura‐Weber und Qun Ren. „Bacterial Adhesion on Soft Materials: Passive Physicochemical Interactions or Active Bacterial Mechanosensing?“ Advanced Healthcare Materials 8, Nr. 8 (18.02.2019): 1801323. http://dx.doi.org/10.1002/adhm.201801323.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

5

Gordon, Vernita D., und Liyun Wang. „Bacterial mechanosensing: the force will be with you, always“. Journal of Cell Science 132, Nr. 7 (01.04.2019): jcs227694. http://dx.doi.org/10.1242/jcs.227694.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

6

Harapanahalli, Akshay K., Jessica A. Younes, Elaine Allan, Henny C. van der Mei und Henk J. Busscher. „Chemical Signals and Mechanosensing in Bacterial Responses to Their Environment“. PLOS Pathogens 11, Nr. 8 (27.08.2015): e1005057. http://dx.doi.org/10.1371/journal.ppat.1005057.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

7

Mordue, James, Nicky O'Boyle, Nikolaj Gadegaard und Andrew J. Roe. „The force awakens: The dark side of mechanosensing in bacterial pathogens“. Cellular Signalling 78 (Februar 2021): 109867. http://dx.doi.org/10.1016/j.cellsig.2020.109867.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

8

Fajardo-Cavazos, Patricia, und Wayne L. Nicholson. „Mechanotransduction in Prokaryotes: A Possible Mechanism of Spaceflight Adaptation“. Life 11, Nr. 1 (07.01.2021): 33. http://dx.doi.org/10.3390/life11010033.

Der volle Inhalt der Quelle

Annotation:

Our understanding of the mechanisms of microgravity perception and response in prokaryotes (Bacteria and Archaea) lag behind those which have been elucidated in eukaryotic organisms. In this hypothesis paper, we: (i) review how eukaryotic cells sense and respond to microgravity using various pathways responsive to unloading of mechanical stress; (ii) we observe that prokaryotic cells possess many structures analogous to mechanosensitive structures in eukaryotes; (iii) we review current evidence indicating that prokaryotes also possess active mechanosensing and mechanotransduction mechanisms; and (iv) we propose a complete mechanotransduction model including mechanisms by which mechanical signals may be transduced to the gene expression apparatus through alterations in bacterial nucleoid architecture, DNA supercoiling, and epigenetic pathways.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

9

Nakayama, Yoshitaka. „Corynebacterium glutamicum Mechanosensing: From Osmoregulation to L-Glutamate Secretion for the Avian Microbiota-Gut-Brain Axis“. Microorganisms 9, Nr. 1 (19.01.2021): 201. http://dx.doi.org/10.3390/microorganisms9010201.

Der volle Inhalt der Quelle

Annotation:

After the discovery of Corynebacterium glutamicum from avian feces-contaminated soil, its enigmatic L-glutamate secretion by corynebacterial MscCG-type mechanosensitive channels has been utilized for industrial monosodium glutamate production. Bacterial mechanosensitive channels are activated directly by increased membrane tension upon hypoosmotic downshock; thus; the physiological significance of the corynebacterial L-glutamate secretion has been considered as adjusting turgor pressure by releasing cytoplasmic solutes. In this review, we present information that corynebacterial mechanosensitive channels have been evolutionally specialized as carriers to secrete L-glutamate into the surrounding environment in their habitats rather than osmotic safety valves. The lipid modulation activation of MscCG channels in L-glutamate production can be explained by the “Force-From-Lipids” and “Force-From-Tethers” mechanosensing paradigms and differs significantly from mechanical activation upon hypoosmotic shock. The review also provides information on the search for evidence that C. glutamicum was originally a gut bacterium in the avian host with the aim of understanding the physiological roles of corynebacterial mechanosensing. C. glutamicum is able to secrete L-glutamate by mechanosensitive channels in the gut microbiota and help the host brain function via the microbiota–gut–brain axis.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

10

Nirody, Jasmine A., Ashley L. Nord und Richard M. Berry. „Load-dependent adaptation near zero load in the bacterial flagellar motor“. Journal of The Royal Society Interface 16, Nr. 159 (02.10.2019): 20190300. http://dx.doi.org/10.1098/rsif.2019.0300.

Der volle Inhalt der Quelle

Annotation:

The bacterial flagellar motor is an ion-powered transmembrane protein complex which drives swimming in many bacterial species. The motor consists of a cytoplasmic ‘rotor’ ring and a number of ‘stator’ units, which are bound to the cell wall of the bacterium. Recently, it has been shown that the number of functional torque-generating stator units in the motor depends on the external load, and suggested that mechanosensing in the flagellar motor is driven via a ‘catch bond’ mechanism in the motor’s stator units. We present a method that allows us to measure—on a single motor—stator unit dynamics across a large range of external loads, including near the zero-torque limit. By attaching superparamagnetic beads to the flagellar hook, we can control the motor’s speed via a rotating magnetic field. We manipulate the motor to four different speed levels in two different ion-motive force (IMF) conditions. This framework allows for a deeper exploration into the mechanism behind load-dependent remodelling by separating out motor properties, such as rotation speed and energy availability in the form of IMF, that affect the motor torque.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

11

Butcher, Jonathan T., und Robert M. Nerem. „Valvular endothelial cells and the mechanoregulation of valvular pathology“. Philosophical Transactions of the Royal Society B: Biological Sciences 362, Nr. 1484 (14.06.2007): 1445–57. http://dx.doi.org/10.1098/rstb.2007.2127.

Der volle Inhalt der Quelle

Annotation:

Endothelial cells are critical mediators of haemodynamic forces and as such are important foci for initiation of vascular pathology. Valvular leaflets are also lined with endothelial cells, though a similar role in mechanosensing has not been demonstrated. Recent evidence has shown that valvular endothelial cells respond morphologically to shear stress, and several studies have implicated valvular endothelial dysfunction in the pathogenesis of disease. This review seeks to combine what is known about vascular and valvular haemodynamics, endothelial response to mechanical stimuli and the pathogenesis of valvular diseases to form a hypothesis as to how mechanical stimuli can initiate valvular endothelial dysfunction and disease progression. From this analysis, it appears that inflow surface-related bacterial/thrombotic vegetative endocarditis is a high shear-driven endothelial denudation phenomenon, while the outflow surface with its related calcific/atherosclerotic degeneration is a low/oscillatory shear-driven endothelial activation phenomenon. Further understanding of these mechanisms may help lead to earlier diagnostic tools and therapeutic strategies.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

12

Dori-Bachash, Mally, Bareket Dassa, Shmuel Pietrokovski und Edouard Jurkevitch. „Proteome-Based Comparative Analyses of Growth Stages Reveal New Cell Cycle-Dependent Functions in the Predatory Bacterium Bdellovibrio bacteriovorus“. Applied and Environmental Microbiology 74, Nr. 23 (03.10.2008): 7152–62. http://dx.doi.org/10.1128/aem.01736-08.

Der volle Inhalt der Quelle

Annotation:

ABSTRACT Bdellovibrio and like organisms are obligate predators of bacteria that are ubiquitously found in the environment. Most exhibit a peculiar dimorphic life cycle during which free-swimming attack-phase (AP) cells search for and invade bacterial prey cells. The invader develops in the prey as a filamentous polynucleoid-containing cell that finally splits into progeny cells. Therapeutic and biocontrol applications of Bdellovibrio in human and animal health and plant health, respectively, have been proposed, but more knowledge of this peculiar cell cycle is needed to develop such applications. A proteomic approach was applied to study cell cycle-dependent expression of the Bdellovibrio bacteriovorus proteome in synchronous cultures of a facultative host-independent (HI) strain able to grow in the absence of prey. Results from two-dimensional gel electrophoresis, mass spectrometry, and temporal expression of selected genes in predicted operons were analyzed. In total, about 21% of the in silico predicted proteome was covered. One hundred ninety-six proteins were identified, including 63 hitherto unknown proteins and 140 life stage-dependent spots. Of those, 47 were differentially expressed, including chemotaxis, attachment, growth- and replication-related, cell wall, and regulatory proteins. Novel cell cycle-dependent adhesion, gliding, mechanosensing, signaling, and hydrolytic functions were assigned. The HI model was further studied by comparing HI and wild-type AP cells, revealing that proteins involved in DNA replication and signaling were deregulated in the former. A complementary analysis of the secreted proteome identified 59 polypeptides, including cell contact proteins and hydrolytic enzymes specific to predatory bacteria.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

13

Dieterle, Martin Philipp, Ayman Husari, Thorsten Steinberg, Xiaoling Wang, Imke Ramminger und Pascal Tomakidi. „From the Matrix to the Nucleus and Back: Mechanobiology in the Light of Health, Pathologies, and Regeneration of Oral Periodontal Tissues“. Biomolecules 11, Nr. 6 (31.05.2021): 824. http://dx.doi.org/10.3390/biom11060824.

Der volle Inhalt der Quelle

Annotation:

Among oral tissues, the periodontium is permanently subjected to mechanical forces resulting from chewing, mastication, or orthodontic appliances. Molecularly, these movements induce a series of subsequent signaling processes, which are embedded in the biological concept of cellular mechanotransduction (MT). Cell and tissue structures, ranging from the extracellular matrix (ECM) to the plasma membrane, the cytosol and the nucleus, are involved in MT. Dysregulation of the diverse, fine-tuned interaction of molecular players responsible for transmitting biophysical environmental information into the cell’s inner milieu can lead to and promote serious diseases, such as periodontitis or oral squamous cell carcinoma (OSCC). Therefore, periodontal integrity and regeneration is highly dependent on the proper integration and regulation of mechanobiological signals in the context of cell behavior. Recent experimental findings have increased the understanding of classical cellular mechanosensing mechanisms by both integrating exogenic factors such as bacterial gingipain proteases and newly discovered cell-inherent functions of mechanoresponsive co-transcriptional regulators such as the Yes-associated protein 1 (YAP1) or the nuclear cytoskeleton. Regarding periodontal MT research, this review offers insights into the current trends and open aspects. Concerning oral regenerative medicine or weakening of periodontal tissue diseases, perspectives on future applications of mechanobiological principles are discussed.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

14

Belas, Robert. „Biofilms, flagella, and mechanosensing of surfaces by bacteria“. Trends in Microbiology 22, Nr. 9 (September 2014): 517–27. http://dx.doi.org/10.1016/j.tim.2014.05.002.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

15

Laventie, Benoît-Joseph, und Urs Jenal. „Surface Sensing and Adaptation in Bacteria“. Annual Review of Microbiology 74, Nr. 1 (08.09.2020): 735–60. http://dx.doi.org/10.1146/annurev-micro-012120-063427.

Der volle Inhalt der Quelle

Annotation:

Bacteria thrive both in liquids and attached to surfaces. The concentration of bacteria on surfaces is generally much higher than in the surrounding environment, offering bacteria ample opportunity for mutualistic, symbiotic, and pathogenic interactions. To efficiently populate surfaces, they have evolved mechanisms to sense mechanical or chemical cues upon contact with solid substrata. This is of particular importance for pathogens that interact with host tissue surfaces. In this review we discuss how bacteria are able to sense surfaces and how they use this information to adapt their physiology and behavior to this new environment. We first survey mechanosensing and chemosensing mechanisms and outline how specific macromolecular structures can inform bacteria about surfaces. We then discuss how mechanical cues are converted to biochemical signals to activate specific cellular processes in a defined chronological order and describe the role of two key second messengers, c-di-GMP and cAMP, in this process.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

16

Rodesney, Christopher A., Brian Roman, Numa Dhamani, Benjamin J. Cooley, Parag Katira, Ahmed Touhami und Vernita D. Gordon. „Mechanosensing of shear by Pseudomonas aeruginosa leads to increased levels of the cyclic-di-GMP signal initiating biofilm development“. Proceedings of the National Academy of Sciences 114, Nr. 23 (22.05.2017): 5906–11. http://dx.doi.org/10.1073/pnas.1703255114.

Der volle Inhalt der Quelle

Annotation:

Biofilms are communities of sessile microbes that are phenotypically distinct from their genetically identical, free-swimming counterparts. Biofilms initiate when bacteria attach to a solid surface. Attachment triggers intracellular signaling to change gene expression from the planktonic to the biofilm phenotype. For Pseudomonas aeruginosa, it has long been known that intracellular levels of the signal cyclic-di-GMP increase upon surface adhesion and that this is required to begin biofilm development. However, what cue is sensed to notify bacteria that they are attached to the surface has not been known. Here, we show that mechanical shear acts as a cue for surface adhesion and activates cyclic-di-GMP signaling. The magnitude of the shear force, and thereby the corresponding activation of cyclic-di-GMP signaling, can be adjusted both by varying the strength of the adhesion that binds bacteria to the surface and by varying the rate of fluid flow over surface-bound bacteria. We show that the envelope protein PilY1 and functional type IV pili are required mechanosensory elements. An analytic model that accounts for the feedback between mechanosensors, cyclic-di-GMP signaling, and production of adhesive polysaccharides describes our data well.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

17

Sokabe, Masahiro, Yasuyuki Sawada, Kimihide Hayakawa und Hitoshi Tatsumi. „1SB0900 Cell mechanosensing by ion channels : from bacteria to human(1SB Emerging MechanoBiology,The 48th Annual Meeting of the Biophysical Society of Japan)“. Seibutsu Butsuri 50, supplement2 (2010): S1. http://dx.doi.org/10.2142/biophys.50.s1_1.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

18

Guo, Shuaiqi, und Jun Liu. „The Bacterial Flagellar Motor: Insights Into Torque Generation, Rotational Switching, and Mechanosensing“. Frontiers in Microbiology 13 (30.05.2022). http://dx.doi.org/10.3389/fmicb.2022.911114.

Der volle Inhalt der Quelle

Annotation:

The flagellar motor is a bidirectional rotary nanomachine used by many bacteria to sense and move through environments of varying complexity. The bidirectional rotation of the motor is governed by interactions between the inner membrane-associated stator units and the C-ring in the cytoplasm. In this review, we take a structural biology perspective to discuss the distinct conformations of the stator complex and the C-ring that regulate bacterial motility by switching rotational direction between the clockwise (CW) and counterclockwise (CCW) senses. We further contextualize recent in situ structural insights into the modulation of the stator units by accessory proteins, such as FliL, to generate full torque. The dynamic structural remodeling of the C-ring and stator complexes as well as their association with signaling and accessory molecules provide a mechanistic basis for how bacteria adjust motility to sense, move through, and survive in specific niches both outside and within host cells and tissues.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

19

Chen, Jing, und Beiyan Nan. „Flagellar Motor Transformed: Biophysical Perspectives of the Myxococcus xanthus Gliding Mechanism“. Frontiers in Microbiology 13 (06.05.2022). http://dx.doi.org/10.3389/fmicb.2022.891694.

Der volle Inhalt der Quelle

Annotation:

Many bacteria move on solid surfaces using gliding motility, without involvement of flagella or pili. Gliding of Myxococcus xanthus is powered by a proton channel homologous to the stators in the bacterial flagellar motor. Instead of being fixed in place and driving the rotation of a circular protein track like the flagellar basal body, the gliding machinery of M. xanthus travels the length of the cell along helical trajectories, while mechanically engaging with the substrate. Such movement entails a different molecular mechanism to generate propulsion on the cell. In this perspective, we will discuss the similarities and differences between the M. xanthus gliding machinery and bacterial flagellar motor, and use biophysical principles to generate hypotheses about the operating mechanism, efficiency, sensitivity to control, and mechanosensing of M. xanthus gliding.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

20

Laganenka, Leanid, María Esteban López, Remy Colin und Victor Sourjik. „Flagellum-Mediated Mechanosensing and RflP Control Motility State of Pathogenic Escherichia coli“. mBio 11, Nr. 2 (24.03.2020). http://dx.doi.org/10.1128/mbio.02269-19.

Der volle Inhalt der Quelle

Annotation:

ABSTRACT Bacterial flagellar motility plays an important role in many processes that occur at surfaces or in hydrogels, including adhesion, biofilm formation, and bacterium-host interactions. Consequently, expression of flagellar genes, as well as genes involved in biofilm formation and virulence, can be regulated by the surface contact. In a few bacterial species, flagella themselves are known to serve as mechanosensors, where an increased load on flagella experienced during surface contact or swimming in viscous media controls gene expression. In this study, we show that gene regulation by motility-dependent mechanosensing is common among pathogenic Escherichia coli strains. This regulatory mechanism requires flagellar rotation, and it enables pathogenic E. coli to repress flagellar genes at low loads in liquid culture, while activating motility in porous medium (soft agar) or upon surface contact. It also controls several other cellular functions, including metabolism and signaling. The mechanosensing response in pathogenic E. coli depends on the negative regulator of motility, RflP (YdiV), which inhibits basal expression of flagellar genes in liquid. While no conditional inhibition of flagellar gene expression in liquid and therefore no upregulation in porous medium was observed in the wild-type commensal or laboratory strains of E. coli, mechanosensitive regulation could be recovered by overexpression of RflP in the laboratory strain. We hypothesize that this conditional activation of flagellar genes in pathogenic E. coli reflects adaptation to the dual role played by flagella and motility during infection. IMPORTANCE Flagella and motility are widespread virulence factors among pathogenic bacteria. Motility enhances the initial host colonization, but the flagellum is a major antigen targeted by the host immune system. Here, we demonstrate that pathogenic E. coli strains employ a mechanosensory function of the flagellar motor to activate flagellar expression under high loads, while repressing it in liquid culture. We hypothesize that this mechanism allows pathogenic E. coli to regulate its motility dependent on the stage of infection, activating flagellar expression upon initial contact with the host epithelium, when motility is beneficial, but reducing it within the host to delay the immune response.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

21

Francis, Michael B., und Joseph A. Sorg. „Dipicolinic Acid Release by Germinating Clostridium difficile Spores Occurs through a Mechanosensing Mechanism“. mSphere 1, Nr. 6 (14.12.2016). http://dx.doi.org/10.1128/msphere.00306-16.

Der volle Inhalt der Quelle

Annotation:

ABSTRACT Clostridium difficile is transmitted between hosts in the form of a dormant spore, and germination by C. difficile spores is required to initiate infection, because the toxins that are necessary for disease are not deposited on the spore form. Importantly, the C. difficile spore germination pathway represents a novel pathway for bacterial spore germination. Prior work has shown that the order of events during C. difficile spore germination (cortex degradation and DPA release) is flipped compared to the events during B. subtilis spore germination, a model organism. Here, we further characterize the C. difficile spore germination pathway and summarize our findings indicating that DPA release by germinating C. difficile spores occurs through a mechanosensing mechanism in response to the degradation of the spore cortex. Classically, dormant endospores are defined by their resistance properties, particularly their resistance to heat. Much of the heat resistance is due to the large amount of dipicolinic acid (DPA) stored within the spore core. During spore germination, DPA is released and allows for rehydration of the otherwise-dehydrated core. In Bacillus subtilis, 7 proteins are encoded by the spoVA operon and are important for DPA release. These proteins receive a signal from the activated germinant receptor and release DPA. This DPA activates the cortex lytic enzyme CwlJ, and cortex degradation begins. In Clostridium difficile, spore germination is initiated in response to certain bile acids and amino acids. These bile acids interact with the CspC germinant receptor, which then transfers the signal to the CspB protease. Activated CspB cleaves the cortex lytic enzyme, pro-SleC, to its active form. Subsequently, DPA is released from the core. C. difficile encodes orthologues of spoVAC, spoVAD, and spoVAE. Of these, the B. subtilis SpoVAC protein was shown to be capable of mechanosensing. Because cortex degradation precedes DPA release during C. difficile spore germination (opposite of what occurs in B. subtilis), we hypothesized that cortex degradation would relieve the osmotic constraints placed on the inner spore membrane and permit DPA release. Here, we assayed germination in the presence of osmolytes, and we found that they can delay DPA release from germinating C. difficile spores while still permitting cortex degradation. Together, our results suggest that DPA release during C. difficile spore germination occurs though a mechanosensing mechanism. IMPORTANCE Clostridium difficile is transmitted between hosts in the form of a dormant spore, and germination by C. difficile spores is required to initiate infection, because the toxins that are necessary for disease are not deposited on the spore form. Importantly, the C. difficile spore germination pathway represents a novel pathway for bacterial spore germination. Prior work has shown that the order of events during C. difficile spore germination (cortex degradation and DPA release) is flipped compared to the events during B. subtilis spore germination, a model organism. Here, we further characterize the C. difficile spore germination pathway and summarize our findings indicating that DPA release by germinating C. difficile spores occurs through a mechanosensing mechanism in response to the degradation of the spore cortex.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

22

Tsagkari, Erifyli, Stephanie Connelly, Zhaowei Liu, Andrew McBride und William T. Sloan. „The role of shear dynamics in biofilm formation“. npj Biofilms and Microbiomes 8, Nr. 1 (29.04.2022). http://dx.doi.org/10.1038/s41522-022-00300-4.

Der volle Inhalt der Quelle

Annotation:

AbstractThere is growing evidence that individual bacteria sense and respond to changes in mechanical loading. However, the subtle responses of multispecies biofilms to dynamic fluid shear stress are not well documented because experiments often fail to disentangle any beneficial effects of shear stress from those delivered by convective transport of vital nutrients. We observed the development of biofilms with lognormally distributed microcolony sizes in drinking water on the walls of flow channels underflow regimes of increasing complexity. First, where regular vortices induced oscillating wall shear and simultaneously enhanced mass transport, which produced the thickest most extensive biofilms. Second, where unsteady uniform flow imposed an oscillating wall shear, with no enhanced transport, and where the biomass and coverage were only 20% smaller. Finally, for uniform steady flows with constant wall shear where the extent, thickness, and density of the biofilms were on average 60% smaller. Thus, the dynamics of shear stress played a significant role in promoting biofilm development, over and above its magnitude or mass transfer effects, and therefore, mechanosensing may prevail in complex multispecies biofilms which could open up new ways of controlling biofilm structure.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Zeitschriftenartikel zum Thema „Bacterial mechanosensing“

Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an