Historical changes in the bird fauna at Coomooboolaroo, northeastern Australia, from the early years of pastoral settlement (1873) to 1999

Currently, a social security number (SSN) is held by almost every legal resident of the United States and works as an important numbering system. However, this was not the case in the early years of the Social Security program and historical changes in SSN holder rates had not been examined sufficiently. It is important to understand the changes in health policies and situations. Thus, the present article examined historical changes in the rates of SSN holders in the United States between 1909 and 2019. Analyses demonstrated that the rates clearly increased. Specifically, in Phase 1 (1909-1919), the rates were low in the early period, but they increased markedly. In Phase 2 (1919-1952), the rates continued to increase gradually. In Phase 3 (1952-2019), the rates were almost 100% and reached saturation. This basic information leads to a better understanding of the health policies and situations, contributing to medical and social science research.

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The Genesis and Internal Dynamics of El Salvador's People's Revolutionary Army, 1970–1976

Behavioral and Brain Sciences ◽

10.1017/s0140525x13009850 ◽

2014 ◽

Vol 38 (01) ◽

pp. 102-129

Author(s):

ALBERTO MARTÍN ÁLVAREZ ◽

EUDALD CORTINA ORERO

Keyword(s):

Latin America ◽

El Salvador ◽

Early Years ◽

Left Wing ◽

Internal Dynamics ◽

Internal Coherence ◽

The 1960S

AbstractUsing interviews with former militants and previously unpublished documents, this article traces the genesis and internal dynamics of the Ejército Revolucionario del Pueblo (People's Revolutionary Army, ERP) in El Salvador during the early years of its existence (1970–6). This period was marked by the inability of the ERP to maintain internal coherence or any consensus on revolutionary strategy, which led to a series of splits and internal fights over control of the organisation. The evidence marshalled in this case study sheds new light on the origins of the armed Salvadorean Left and thus contributes to a wider understanding of the processes of formation and internal dynamics of armed left-wing groups that emerged from the 1960s onwards in Latin America.

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Image quality vs data obtainment in biological electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100141950 ◽

1986 ◽

Vol 44 ◽

pp. 42-43

Author(s):

J. E. Johnson

Keyword(s):

Electron Microscopy ◽

Endoplasmic Reticulum ◽

Electron Beam ◽

Image Quality ◽

High Speed ◽

Early Period ◽

Early Years ◽

Fluorescent Screen ◽

Embedding Medium

In the early years of biological electron microscopy, scientists had their hands full attempting to describe the cellular microcosm that was suddenly before them on the fluorescent screen. Mitochondria, Golgi, endoplasmic reticulum, and other myriad organelles were being examined, micrographed, and documented in the literature. A major problem of that early period was the development of methods to cut sections thin enough to study under the electron beam. A microtome designed in 1943 moved the specimen toward a rotary “Cyclone” knife revolving at 12,500 RPM, or 1000 times as fast as an ordinary microtome. It was claimed that no embedding medium was necessary or that soft embedding media could be used. Collecting the sections thus cut sounded a little precarious: “The 0.1 micron sections cut with the high speed knife fly out at a tangent and are dispersed in the air. They may be collected... on... screens held near the knife“.

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