Influence Of Motility Research Articles

Motility Plays an Important Role in the Lifetime of Mammalian Lipid Droplets.

The lipid droplet is a kind of organelle that stores neutral lipids in cells. Recent studies have found that in addition to energy storage, lipid droplets also play an important role in biological processes such as resistance to stress, immunity, cell proliferation, apoptosis, and signal transduction. Lipid droplets are formed at the endoplasmic reticulum, and mature lipid droplets participate in various cellular processes. Lipid droplets are decomposed by lipase and lysosomes. In the life of a lipid droplet, the most important thing is to interact with other organelles, including the endoplasmic reticulum, mitochondria, peroxisomes, and autophagic lysosomes. The interaction between lipid droplets and other organelles requires them to be close to each other, which inevitably involves the motility of lipid droplets. In fact, through many microscopic observation techniques, researchers have discovered that lipid droplets are highly dynamic organelles that move quickly. This paper reviews the process of lipid droplet motility, focusing on explaining the molecular basis of lipid droplet motility, the factors that regulate lipid droplet motility, and the influence of motility on the formation and decomposition of lipid droplets. In addition, this paper also proposes several unresolved problems for lipid droplet motility. Finally, this paper makes predictions about the future research of lipid droplet motility.

The influence of motility on bacterial accumulation in a microporous channel.

We study the transport of bacteria in a porous media modeled by a square channel containing one cylindrical obstacle via molecular dynamics simulations coupled to a lattice Boltzmann fluid. Our bacteria model is a rod-shaped rigid body which is propelled by a force-free mechanism. To account for the behavior of living bacteria, the model also incorporates a run-and-tumble process. The model bacteria are capable of hydrodynamically interacting with both of the channel walls and the obstacle. This enables the bacteria to get reoriented when experiencing a shear-flow. We demonstrate that this model is capable of reproducing the bacterial accumulation on the rear side of an obstacle, as has recently been experimentally observed by [G. L. Miño, et al., Adv. Microbiol., 2018, 8, 451] using E. coli bacteria. By systematically varying the external flow strength and the motility of the bacteria, we resolve the interplay between the local flow strength and the swimming characteristics that lead to the accumulation. Moreover, by changing the geometry of the channel, we also reveal the important role of the interactions between the bacteria and the confining walls for the accumulation process.

Chemotactic preferences govern competition and pattern formation in simulated two-strain microbial communities.

Substrate competition is a common mode of microbial interaction in natural environments. While growth properties play an important and well-studied role in competition, we here focus on the influence of motility. In a simulated two-strain community populating a homogeneous two-dimensional environment, strains competed for a common substrate and only differed in their chemotactic preference, either responding more sensitively to a chemoattractant excreted by themselves or responding more sensitively to substrate. Starting from homogeneous distributions, three possible behaviors were observed depending on the competitors' chemotactic preferences: (i) distributions remained homogeneous, (ii) patterns formed but dissolved at a later time point, resulting in a shifted community composition, and (iii) patterns emerged and led to the extinction of one strain. When patterns formed, the more aggregating strain populated the core of microbial aggregates where starving conditions prevailed, while the less aggregating strain populated the more productive zones at the fringe or outside aggregates, leading to a competitive advantage of the less aggregating strain. The presence of a competitor was found to modulate a strain's behavior, either suppressing or promoting aggregate formation. This observation provides a potential mechanism by which an aggregated lifestyle might evolve even if it is initially disadvantageous. Adverse effects can be avoided as a competitor hinders aggregate formation by a strain which has just acquired this ability. The presented results highlight both, the importance of microbial motility for competition and pattern formation, and the importance of the temporal evolution, or history, of microbial communities when trying to explain an observed distribution.

Motility induced changes in viscosity of suspensions of swimming microbes in extensional flows.

Suspensions of motile cells are model systems for understanding the unique mechanical properties of living materials which often consist of ensembles of self-propelled particles. We present here a quantitative comparison of theory against experiment for the rheology of such suspensions in extensional flows. The influence of motility on viscosities of cell suspensions is studied using a novel acoustically-driven microfluidic capillary-breakup extensional rheometer. Motility increases the extensional viscosity of suspensions of algal pullers, but decreases it in the case of bacterial or sperm pushers. A recent model [Saintillan, Phys. Rev. E: Stat., Nonlinear, Soft Matter Phys., 2010, 81, 56307] for dilute active suspensions is extended to obtain predictions for higher concentrations, after independently obtaining parameters such as swimming speeds and diffusivities. We show that details of body and flagellar shape can significantly determine macroscale rheological behaviour.

Self and the Influence of Motility in Expressing One's Opinions

Problem StatementFor the definition of self and the capacity of individuals to express their opinions, education has a decisive role, beyond standards. All is achieved through the means of a disciplined mind, and a body fully physically prepared to obey any command received from the cortex, where the latter acts as a selective filter in shaping one's self. Purpose of StudyThis research started from the hypothesis according to which self is influenced by motor activities, and that individuals who receive a proper motor education also possess a special ability and strength in expressing freely their opinions, as compared to those who have a sedentary life or are absent from physical training for different reasons, and have no personal opinions. The group of subjects was made from 86 students of the Petroleum -Gas University of Ploieşti (boys and girls), enrolled in the same institution and having similar motor and intellectual interests. Research MethodsThe bibliographic study methods; the observation method; the enquiry method (questionnaire, discussion, enquiry, etc.); the pedagogical experiment method; the statistical-mathematical method; the observation method; the graphical method. FindingsStudents who are physically active express their opinions freely, as compared to those who have a sedentary life or are absent from physical training for different reasons, and are tolerant to various attitudes, mainly unjustified, are incapable of expressing personal opinions. This situation would modify in time, as a consequence of the implementation of certain participation rules for lessons, which implied a number of attended classes they had to have in order to promote the university year. ConclusionsAs a result of the implementation of a set of rules with a demanding-corrective character, the behaviour of sedentary or absent students suffered a positive modification, as they managed to leave the cone of shadow of “spineless people”, and had the capacity of expressing freely their opinions.

Analysis of the role of the two flagella of Bradyrhizobium japonicum in competition for nodulation of soybean

Bradyrhizobium japonicum has two types of flagella. One has thin filaments consisting of the 33-kDa flagellins FliCI and FliCII (FliCI-II) and the other has thick filaments consisting of the 65-kDa flagellins FliC1, FliC2, FliC3, and FliC4 (FliC1-4). To investigate the roles of each flagellum in competition for nodulation, we obtained mutants deleted in fliCI-II and/or fliC1-4 in the genomic backgrounds of two derivatives from the reference strain USDA 110: the streptomycin-resistant derivative LP 3004 and its more motile derivative LP 3008. All mutations diminished swimming motility. When each mutant was co-inoculated with the parental strain on soybean plants cultivated in vermiculite either at field capacity or flooded, their competitiveness differed according to the flagellin altered. ΔfliCI-II mutants were more competitive, occupying 64-80% of the nodules, while ΔfliC1-4 mutants occupied 45-49% of the nodules. Occupation by the nonmotile double mutant decreased from 55% to 11% as the water content of the vermiculite increased from 85% to 95% field capacity to flooding. These results indicate that the influence of motility on competitiveness depended on the water status of the rooting substrate.

Distribution of aerobic motile and non-motile bacteria within the capillary fringe of silica sand

Retention of bacterial cells as “particles” by silica sand during formation of a capillary fringe (CF) and the influence of motility was examined with motile Pseudomonas putida and non-motile Corynebacterium glutamicum suspensions in the absence of nutrients. The fractional retention of C. glutamicum cells at all regions of the CF was higher than for P. putida cells, most probably due to the motility of P. putida. Only about 5% of P. putida cells and almost no C. glutamicum cells reached the upper end of a CF of 10 cm height. With cell suspensions of P. putida and C. glutamicum in nutrient broth the development of a CF in silica sand fractions of 355–710 μm and 710–1000 μm respectively, was finished after about 6 h. Growth of cells proceeded for about 6 days. P. putida formed a biofilm on silica grains, whereas no attachment of C. glutamicum on silica sand occurred. Relative cell densities of C. glutamicum on the bottom and in the upper regions of the CF were always lower than those of P. putida and were also lower than those reached in suspended cultures with the same medium. In coarse sand the motile P. putida cells reached significantly higher cell densities in upper CF regions than in fine sand. Growth of C. glutamicum in the CF apparently was slower and a higher proportion of the energy was required for maintenance. Whereas cell densities of P. putida, in CFs of both sand fractions, varied less than one order of magnitude, those of C. glutamicum varied in a wider range from the basis to the top of the CF. Analyses of the esterase activity of P. putida and C. glutamicum with fluorescein diacetate (FDA) revealed that the cells in higher CF regions were significantly more active than those at the bottom of the CF. Furthermore, a significant correlation ( r = 0.66, p < 0.01) between cells ml −1 and the FDA conversion to fluorescein was found.

Microgravity, bacteria, and the influence of motility

Space microbiology studies date back to the 1960s, with most investigations reporting that increased bacterial populations occur in flight compared to ground controls. Several exceptions to these findings, however, have created controversy and complicated explanations of how, or whether, microgravity affects microorganisms. Upon closer examination of the literature, we identified a trend relating cell motility to experimental outcome. Related studies conducted in microgravity analog devices, such as the clinostat or rotating wall vessel bioreactor, further corroborate this trend. We review the literature regarding bacterial growth experiments conducted in space (and using microgravity analogs) and analyze the influence of bacterial motility.

Influence of motility and vitality in intracytoplasmic sperm injection with ejaculated and testicular sperm

The vitality of spermatozoa used for intracytoplasmic sperm injection (ICSI) is a crucial factor for fertilization, establishment and outcome of a pregnancy in assisted reproductive technique cycles. The sperm origin may also be a limiting factor, although little is known about this issue. It is known that the motility of injected spermatozoa and their origin from ejaculate or testicular biopsies are important predictors in terms of fertilization, pregnancy and birth rates. Oocytes of patients in 2593 cycles were retrieved in our in vitro fertilization programme and inseminated via ICSI. We used motile (group 1, n = 2317) or immotile ejaculated spermatozoa (group 2, n = 79), motile sperm retrieved from testicular biopsies (group 3, n = 62) and immotile spermatozoa from testicular biopsies (group 4, n = 135). Female age and number of oocytes retrieved did not differ significantly among the groups. The fertilization rates were as follows: 67.1% in group 1, 49.8% in group 2, 68.3% in group 3 and 47.8% in group 4. The pregnancy rates in cases where three embryos had been transferred amounted to 35.7% in group 1, 17.3% in group 2, 38.3% in group 3 and 20.5% in group 4. The embryo quality showed no differences between groups 1 and 3 (14.5), and between groups 2 (11.8) and 4 (10.8). The abortion rate was similar in groups 1-3, but increased in group 4 (26.6%, 27.3%, 31.6% and 55.5%). Irrespective of their origin, the fertilization potential of injected spermatozoa was found to be influenced by motility. The resulting pregnancy and birth rates, i.e. the potential of the resulting embryos to implant and to achieve viable pregnancies, seem to be additionally dependent on the sperm origin. This was well shown by declining rates when spermatozoa in a relatively early stage of maturity had been used. We see increasing evidence that the degree of sperm maturity has an important impact on the outcome of ICSI. In obstructive azoospermia, spermatozoa retrieved from the epididymis should be used rather than testicular biopsy spermatozoa, or testicular sperm should be preincubated in culture medium before ICSI.

Influence of motility on the outcome of in vitro fertilization/intracytoplasmic sperm injection with fresh vs. frozen testicular sperm from men with obstructive azoospermia

Objective To assess the efficacy of fresh vs. frozen testicular sperm on fertilization and pregnancy using intracytoplasmic sperm injection. Design Retrospective study. Setting Hospital-based infertility research laboratory. Patient(s) One hundred sixty patients with obstructive azoospermia undergoing testicular sperm extraction (TESE). Intervention(s) Sections of seminiferous tubule were cryopreserved after TESE. Sperm motility and fertilizing ability were determined after thawing seminiferous tubule sections. Main outcome measure(s) Sperm motility and optimal fertilization and pregnancy rate. Result(s) Intracytoplasmic sperm injection was performed using fresh testicular sperm (fresh-sperm group; 84 cases) and thawed seminiferous tubules (thawed-sperm group; 177 cases). The overall fertilization rate was 65.4%, and the pregnancy rate was 34.0%. In the fresh-sperm group, the fertilization rate was 70.9%, and the pregnancy rate was 38.8%. In the thawed-sperm group, the fertilization rate was 62.7%, and the pregnancy rate was 21.7%. Fertilization rates were higher using fresh motile sperm vs. nonmotile sperm (77.0% vs. 29.3%). Pregnancy rates were higher using fresh motile sperm vs. nonmotile sperm (44.3% vs. 20.0%). The fertilization and pregnancy rates of motile vs. nonmotile sperm extracted from the thawed seminiferous tubule were 70.0% vs. 50.9% and 33.9% vs. 27.3%, respectively. Motile spermatozoa could be obtained several hours after thawing in most of the cases. Conclusion(s) Optimal fertilization and pregnancy rates were achieved using fresh vs. frozen sperm obtained using TESE when motile sperm were identified. Motile spermatozoa provided superior results to nonmotile sperm and are necessary for optimal fertilization and pregnancy outcomes.

Horizontal and vertical movement of Pseudomonas fluorescens toward exudate of Macrophomina phaseolina in soil: influence of motility and soil properties

The role of motility and cell surface hydrophobicity in transport and dispersal of Pseudomonas fluorescens strains LAM1-hydrophilic, LAM2-hydrophobic and LAM(NM) (non-motile mutant of LAM2) under different soil conditions was studied. Maximum adhesion was recorded for LAM2 in clay loam (70%), followed by sandy loam (68%) and sandy soil (40%). Vertical migration of P fluorescens isolates in soils was recorded at 5 and 25 cm flow of wafer or M. phaseolina exudate. In all the treatments, LAM1 exhibited maximum migration followed, by LAM2 and LAM(NM). The rate of migration of such isolates was lowered in water irrigated soils compared to those irrigated with M. phaseolina exudate. In sandy soil, cells of LAM1 migrated up to 13 cm in comparison to LAM2 (11 cm) and LAN(NM) (9 cm) at 5 cm flow of fungal exudate. Population of LAM1, LAM2 and LAM(NM) was 5.7, 5.68 and 5.61 log cfu g(-1) soil at 1 cm depth, but it decreased to 2.56, 2.21 and 1.99 log cfu during migration up to 11 cm in sandy soil at 5 cm flow of fungal exudate. Greater motility was observed in sandy soil irrigated with water or fungal exudate, followed by sandy loam and clay loam. In general, filtration coefficient (lambda) of P. fluorescens was higher in soils irrigated with 5 cm of water or exudate than with 25 cm of irrigation. The horizontal movement of P. fluorescens strains in sandy soil adjusted at different psi m showed marked reduction with decrease in psi m. The non-motile LAN(NM) did not show chemotactic response and migrated up to a maximum of 3 mm in saturated soils (0 kPa). After 96 h, LAM1 and LAM2 migrated upto 35 and 29 mm respectively in sandy soil. Motile isolates had significantly greater colonization of M. phaseolina sclerotia over the non-motile mutant.

Newer physiology of absorption from the intestine.

Article1 November 1959NEWER PHYSIOLOGY OF ABSORPTION FROM THE INTESTINERICHARD J. REITEMEIER, M.D.RICHARD J. REITEMEIER, M.D.Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-51-5-993 SectionsAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail ExcerptIncrease in knowledge of the physiology of absorption by the gastrointestinal tract has not kept pace with advances in knowledge of renal and cardiac physiology. Contributing factors that, in part, explain this lack of progress include the relative inaccessibility of the gastrointestinal tract, its considerable length, the difficulty of sampling the portal blood, and the scarcity of adequate methods for measurement of absorption. In recent years, however, new tools and technics have appeared and have stimulated new interest and efforts. An attempt has been made in this discussion to survey only a part of the considerable literature in the field...Bibliography1. BensonChandlerVansteenhuyseGagnon JAGNFEJO: Studies concerning the site of fat absorption in the small intestine of the rat, Gastroenterology 30: 53, 1956. CrossrefMedlineGoogle Scholar2. BorgströmDahlqvistLundhSjövall BAGJ: Studies of intestinal digestion and absorption in the human, J. Clin. Investigation 36: 1521, 1957. CrossrefMedlineGoogle Scholar3. BeresWengerKirsner PJJB: The use of I131 triolein in the study of absorptive disorders in man, Gastroenterology 32: 1, 1957. CrossrefMedlineGoogle Scholar4. McKennaBourneMatzko RDRHA: The use of I131 labeled fat in the study of fat digestion and absorption in normal individuals and in patients with diseases of fat absorption, Gastroenterology 32: 17, 1957. CrossrefMedlineGoogle Scholar5. ShingletonBaylinIsleySandersRuffin WWGJJKAPJM: The evaluation of pancreatic function by use of I131 labeled fat, Gastroenterology 32: 28, 1957. CrossrefMedlineGoogle Scholar6. RuffinKeeverChearsShingletonBaylinIsleySanders JMICCWWGJJKAP: Further observations on the use of I131-labeled lipids in the study of diseases of the gastrointestinal tract, Gastroenterology 34: 484, 1958. CrossrefMedlineGoogle Scholar7. GrossmanJordan MIPH: The radio-iodinated triolein test for steatorrhea, Gastroenterology 34: 892, 1958. CrossrefMedlineGoogle Scholar8. KaplanEdidinFruinBaker EBDRCLA: Intestinal absorption of iodine131-labeled triolein and oleic acid in normal subjects and in steatorrhea, Gastroenterology 34: 901, 1958. CrossrefMedlineGoogle Scholar9. BerkowitzSklaroffWoldowJacobsLikoff DDAAGW: Blood absorptive patterns of isotopically-labeled fat and fatty acid, Ann. Int. Med. 50: 247, 1959. LinkGoogle Scholar10. MoertelOwenScudamoreWollaeger CGCAHHEE: Personal communication to the author. Google Scholar11. Van HandelZilversmit EDB: Limitation of radioiodine as a label for fat, J. Lab. and Clin. Med. 52: 831, 1958. MedlineGoogle Scholar12. BensonCulverRaglandJonesDrummeyBougas JAPJSCMGDE: The d-xylose absorption test in malabsorption syndromes, New England J. Med. 256: 335, 1957. CrossrefMedlineGoogle Scholar13. HalstedSwendseidLewisGasster JAMEPMM: Mechanisms involved in the development of vitamin B12 deficiency, Gastroenterology 30: 21, 1956. CrossrefMedlineGoogle Scholar14. ScudamoreHagedornWollaegerOwen HHABEECA: Diverticulosis of the small intestine and macrocytic anemia with report of two cases and studies on absorption of radioactive vitamin B12 , Gastroenterology 34: 66, 1958. CrossrefMedlineGoogle Scholar15. Glass GB: Intestinal absorption and hepatic uptake of vitamin B12 in diseases of the gastrointestinal tract, Gastroenterology 30: 37, 1956. CrossrefMedlineGoogle Scholar16. GräsbeckKanteroSiurala RIM: Influence of calcium ions on vitamin B12 absorption in steatorrhea and pernicious anaemia, Lancet 1: 234, 1959. CrossrefMedlineGoogle Scholar17. BoothMollin CCDL: The site of absorption of vitamin B12 in man, Lancet 1: 18, 1959. CrossrefMedlineGoogle Scholar18. VisscherFetcherCarrGregorBusheyBarker MBESCWHPMSDE: Isotopic tracer studies on the movement of water and ions between intestinal lumen and blood, Am. J. Physiol. 142: 550, 1944. CrossrefGoogle Scholar19. ScholerCode JFCF: Rate of absorption of water from stomach and small bowel of human beings, Gastroenterology 27: 565, 1954. CrossrefMedlineGoogle Scholar20. ScholerOrvisHigginsCode JFALJACF: Use of dual isotopes in determination of rates of absorption in intact animals, Am. J. Physiol. 183: 659, 1955. Google Scholar21. ReitemeierCodeOrvis RJCFAL: Comparison of rate of absorption of labeled sodium and water from upper small intestine of healthy human beings, J. Appl. Physiol. 10: 256, 1957. CrossrefMedlineGoogle Scholar22. LeeCodeScholer PRCFJF: The influence of varying concentrations of sodium chloride on the rate of absorption of water from the stomach and small bowel of human beings, Gastroenterology 29: 1008, 1955. CrossrefMedlineGoogle Scholar23. HigginsLeeScholerReitemeierCodeWollaeger JAPRJFRJCFEE: Absorption of water and sodium from the small intestine of patients with nontropical sprue, J. Clin. Investigation 36: 265, 1957. CrossrefMedlineGoogle Scholar24. HigginsCodeOrvis JACFAL: The influence of motility on the rate of absorption of sodium and water from the small intestine of healthy persons, Gastroenterology 31: 708, 1956. CrossrefMedlineGoogle Scholar This content is PDF only. To continue reading please click on the PDF icon. Author, Article, and Disclosure InformationAffiliations: Rochester, Minnesota*Received for publication May 16, 1959.Presented at the Fortieth Annual Session of The American College of Physicians, Chicago, Illinois, April 22, 1959.From the Section of Medicine, Mayo Clinic and Mayo Foundation, Rochester, Minnesota.The Mayo Foundation is a part of the Graduate School of the University of Minnesota.Requests for reprints should be addressed to Section of Publications, Mayo Clinic, Rochester, Minnesota. PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics Cited byPHARMACOKINETICS AS A BASIC MEDICAL PROBLEM 1 November 1959Volume 51, Issue 5Page: 993-1002KeywordsBileBloodCalciumDigestionGastrointestinal tractGraduate medical educationIleumNutrientsRenal physiology ePublished: 1 December 2008 Issue Published: 1 November 1959 PDF downloadLoading ...

The Influence of Motility on the Rate of Absorption of Sodium and Water from the Small Intestine of Healthy Persons

The Influence of Motility on the Rate of Absorption of Sodium and Water from the Small Intestine of Healthy Persons