THE MORPHOLOGY OF BACTERIUM SHIGAE CULTIVATED ON VARIOUS MEDIA FAVORABLE TO THE DEVELOPMENT OF FILTERABILITY AND LIFE CYCLE FORMS

A simple micro motion picture apparatus has been developed which is so inexpensive to construct and to operate that it can be used regularly for bacteriological research. With this equipment about 6000 feet of film representing 600 hours of photography have been made of B. shigae growing upon various solid media. These pictures illustrate the principal phenomena accompanying the development of this organism on ordinary nutrient media, on media consisting exclusively of either peptones or proteins, and on media containing small amounts of LiCl. Information has thus been gained concerning the existence of a life cycle in the Shiga bacillus and concerning its filterability through Berkefeld filters. The formation and history of the various "life cycle forms" are recorded but the evidence does not point to them as phases of actual cycles. In "filterable" B. shigae cultures—such as those grown in the so-called "K" broth or in lithium chloride-containing media—many small and short rods are present. It has been found that these dwarfed organisms pass through filters impervious to the cells of rapidly growing normal cultures. This offers a simple explanation of "quick reversions." The present experiments do not provide conclusive information concerning the slower reversions which are supposed to occur only after many days of treatment and incubation.

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BACTERIAL GROWTH AND MULTIPLICATION AS DISCLOSED BY MICRO MOTION PICTURES

Journal of Experimental Medicine ◽

10.1084/jem.59.3.381 ◽

1934 ◽

Vol 59 (3) ◽

pp. 381-391 ◽

Cited By ~ 5

Author(s):

Ralph W. G. Wyckoff

Keyword(s):

Life Cycle ◽

Internal Structure ◽

Motion Picture ◽

Bacterial Growth ◽

Motion Pictures ◽

Bacterial Division ◽

Micro Motion ◽

Number Of Bacteria

Using a micro motion picture technique for making records, studies covering several thousand hours of observation have been made of the growth of a number of bacteria. On the basis of these experiments a discussion is offered of bacterial division and its influence on gross colony appearance, of different kinds of pleomorphism that have been observed, and of the nature of the internal structure that is seen in some bacteria. Several of the microorganisms chosen for examination are ones that have been thought to give evidence of life cycle phenomena. The present pictures, however, contain no evidence of a bacterial cycle in the commonly accepted meaning of the term.

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A new direction to understand the life cycle of the Japanese pine sawyer considering the selection strategy of instar pathways

Scientific Reports ◽

10.1038/s41598-020-73344-1 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Su Bin Kim ◽

Dong-Soon Kim

Keyword(s):

Life History ◽

Life Cycle ◽

Pine Wilt Disease ◽

Bursaphelenchus Xylophilus ◽

Selection Strategy ◽

Thermal Environments ◽

Vector Management ◽

History Of ◽

Pass Through ◽

Japanese Pine Sawyer

Abstract The Japanese pine sawyer, Monochamus alternatus Hope (Coleoptera: Cerambycidae), transfers the pine wood nematode, Bursaphelenchus xylophilus (Steiner and Buhrer) that causes pine wilt disease (PWD), especially in Asian countries. The key for the control of PWD is primarily focused on vector management. Thus, understanding the exact life history of M. alternatus is required. Since the late 1980s, the life cycle of M. alternatus has been accepted under the assumption that the final larvae pass four instars in the field. This study is revising the previous error for the life cycle hypothesis of M. alternatus by finding various instar pathways, which pathway is defined as the number of instars that larvae pass through prior to pupation. We confirm experimentally that the overwintered fourth or fifth instar larvae directly pupate to emerge as adults, indicating the presence of four and five instar pathways, respectively. The selection of instar pathway might be determined primarily by habitat temperature. This information will be useful to explain the variation of life history in M. alternatus populations worldwide based on the thermal environments, and also can be served to predict the northern distribution limit by applying the threshold degree-days for the completion of four instar pathway.

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Observations on Bilharziasis amongst the Egyptian Expeditionary Force

Parasitology ◽

10.1017/s0031182000013998 ◽

1920 ◽

Vol 12 (1) ◽

pp. 33-71 ◽

Cited By ~ 31

Author(s):

Philip Manson-Bahr ◽

N. Hamilton Fairley

Keyword(s):

Life History ◽

Life Cycle ◽

Body Cavity ◽

Portal System ◽

Digenetic Trematodes ◽

History Of ◽

Adult Trematode ◽

Pass Through ◽

Water Canals ◽

Germinal Cells

In 1851, Bilharz (1852) first discovered paired adult trematode worms originally named after him in the portal system of an Egyptian fellah. Subsequently, investigations of the deposits of ova in excreta were made, but numerous attempts by Cobbold, Sonsino, Lortet and Vialleton (1894) and others, to unravel the life history of the parasite, failed. Looss (1896), appreciating that the digenetic trematodes must necessarily pass through a molluscan intermediary, dissected many species of snails collected from the fresh-water canals around Cairo. He failed to find the cercariae of bilharzia, and discarded the hypothesis of an intermediate molluscan host. As, however, the miracidium of Schistosomum haematobium contained germinal cells within its body cavity, it must, naturally, he argued, have been destined to produce sporocysts at some stage of its life cycle. In view of this, Looss evolved the hypothesis that man acted simultaneously as the intermediary, as well as the definitive host of this parasite.

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: A Million and One Nights A History of the Motion Picture Through 1925 . Terry Ramsaye.

Film Quarterly ◽

10.1525/fq.1964.17.4.04a00410 ◽

1964 ◽

Vol 17 (4) ◽

pp. 64-64

Author(s):

Ernest Callenbach

Keyword(s):

Motion Picture ◽

History Of

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Rites of Passage

10.1093/oso/9780198702603.003.0007 ◽

2018 ◽

Author(s):

Axel Michaels

Keyword(s):

Life Cycle ◽

Old Age ◽

Sexual Maturity ◽

Rites Of Passage ◽

Life And Death ◽

Transformational Process ◽

Local Contexts ◽

Vulnerable Community ◽

History Of ◽

The Individual

This chapter examines the classical Hindu life-cycle rites, the term saṃskāra and its history, and the main sources (Gṛhyasūtras and Dharma texts). It presents a history of the traditional saṃskāras and variants in local contexts, especially in Nepal. It describes prenatal, birth and childhood, initiation, marriage, old-age, death, and ancestor rituals. Finally, it analyzes the transformational process of these life-cycle rituals in the light of general theories on rites of passage. It proposes, in saṃskāras, man equates himself with the unchangeable and thus seems to counteract the uncertainty of the future, of life and death, since persons are confronted with their finite existence. For evidently every change, whether social or biological, represents a danger for the cohesion of the vulnerable community of the individual and society. These rituals then become an attempt of relegating the effects of nature or of mortality: birth, teething, sexual maturity, reproduction, and dying.

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Endoscopic Removal of a Press-Through Pack from the Anal Canal

Case Reports in Gastroenterology ◽

10.1159/000511751 ◽

2021 ◽

pp. 137-141

Author(s):

Ayaka Takasu ◽

Takashi Ikeya ◽

Katsuyuki Fukuda

Keyword(s):

Small Intestine ◽

Anal Canal ◽

Large Intestine ◽

Digital Rectal Examination ◽

Anal Pain ◽

Endoscopic Removal ◽

Mild Dementia ◽

Anal Fissures ◽

History Of ◽

Pass Through

The incidence of press-through pack (PTP) ingestion has been increasing. In many cases, the ingested PTP is lodged in the esophagus. Here, we report a case of endoscopic removal of a PTP from the anal canal. An 89-year-old man with mild dementia presented with a 3-day history of anal pain. On digital rectal examination, we felt a hard and sharp object, which could not be manually removed due to its shape. Therefore, it was removed endoscopically. We inserted an endoscope with a large-caliber soft oblique cap and observed the PTP in the anal canal. It was successfully removed using grasping forceps. The patient was stable, with only mild anal fissures, and no serious complications such as perforation and bleeding were observed. It is generally recognized that a PTP that reaches the large intestine is naturally expelled. Even if a PTP could pass through the pylorus or the small intestine, it could still be difficult to discharge naturally from the anus without discomfort or pain, as in this case.

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Introduction: History of Life Cycle Costing, Its Categorization, and Its Basic Framework

Environmental Life Cycle Costing ◽

10.1201/9781420054736-9 ◽

2008 ◽

pp. 35-50

Keyword(s):

Life Cycle ◽

Life Cycle Costing ◽

Introduction History ◽

Basic Framework ◽

History Of

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Rupture-dependent breakdown energy in fault models with thermo-hydro-mechanical processes

10.5194/se-2020-115 ◽

2020 ◽

Author(s):

Valère Lambert ◽

Nadia Lapusta

Keyword(s):

Material Property ◽

Numerical Models ◽

Slip Rate ◽

Shear Cracks ◽

Dynamic Rupture ◽

Rupture Dynamics ◽

Stress Changes ◽

History Of ◽

Thermal Pressurization ◽

Pass Through

Abstract. Substantial insight into earthquake source processes has resulted from considering frictional ruptures analogous to cohesive-zone shear cracks from fracture mechanics. This analogy holds for slip-weakening representations of fault friction that encapsulate the resistance to rupture propagation in the form of breakdown energy, analogous to fracture energy, prescribed in advance as if it were a material property of the fault interface. Here, we use numerical models of earthquake sequences with enhanced weakening due to thermal pressurization of pore fluids to show how accounting for thermo-hydro-mechanical processes during dynamic shear ruptures makes breakdown energy rupture-dependent. We find that local breakdown energy is neither a constant material property nor uniquely defined by the amount of slip attained during rupture, but depends on how that slip is achieved through the history of slip rate and dynamic stress changes during the rupture process. As a consequence, the frictional breakdown energy of the same location along the fault can vary significantly in different earthquake ruptures that pass through. These results suggest the need for re-examining the assumption of pre-determined frictional breakdown energy common in dynamic rupture modeling and for better understanding of the factors that control rupture dynamics in the presence of thermo-hydro-mechanical processes.

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The reproduction and larval development of Nereis fucata (Savigny)

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400015605 ◽

1959 ◽

Vol 38 (1) ◽

pp. 65-80 ◽

Cited By ~ 10

Author(s):

J. B. Brown-Gilpin

Keyword(s):

Life History ◽

Life Cycle ◽

Experimental Methods ◽

Point Of View ◽

Hermit Crabs ◽

Special Importance ◽

Reproductive Patterns ◽

Complete Life Cycle ◽

History Of ◽

The Many

The wide variety of reproductive patterns and behaviour in the many species of Nereidae already studied clearly justifies further research. But the life history of Nereis fucata (Savigny) is not only of interest from the comparative point of view. Its commensal habit (it occurs within shells occupied by hermit crabs) immediately gives it a special importance. This alone warrants a detailed study, particularly as no commensal polychaete has yet been reared through to metamorphosis and settlement on its host (Davenport, 1955; Davenport & Hickok, 1957). The numerous interesting problems which arise, and the experimental methods needed to study them, are, however, beyond the range of a paper on nereid development. It is therefore proposed to confine the present account to the reproduction and development up to the time when the larvae settle on the bottom. The complete life cycle, the mechanism of host-adoption, and related topics, will be reported in later papers.

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