Mid-20th Century (mid-20th + century)

Distribution by Scientific Domains


Selected Abstracts


Contributions of Anopheles larval control to malaria suppression in tropical Africa: review of achievements and potential

MEDICAL AND VETERINARY ENTOMOLOGY, Issue 1 2007
K. WALKER
Abstract Malaria vector control targeting the larval stages of mosquitoes was applied successfully against many species of Anopheles (Diptera: Culicidae) in malarious countries until the mid-20th Century. Since the introduction of DDT in the 1940s and the associated development of indoor residual spraying (IRS), which usually has a more powerful impact than larval control on vectorial capacity, the focus of malaria prevention programmes has shifted to the control of adult vectors. In the Afrotropical Region, where malaria is transmitted mainly by Anopheles funestus Giles and members of the Anopheles gambiae Giles complex, gaps in information on larval ecology and the ability of An. gambiae sensu lato to exploit a wide variety of larval habitats have discouraged efforts to develop and implement larval control strategies. Opportunities to complement adulticiding with other components of integrated vector management, along with concerns about insecticide resistance, environmental impacts, rising costs of IRS and logistical constraints, have stimulated renewed interest in larval control of malaria vectors. Techniques include environmental management, involving the temporary or permanent removal of anopheline larval habitats, as well as larviciding with chemical or biological agents. This present review covers large-scale trials of anopheline larval control methods, focusing on field studies in Africa conducted within the past 15 years. Although such studies are limited in number and scope, their results suggest that targeting larvae, particularly in human-made habitats, can significantly reduce malaria transmission in appropriate settings. These approaches are especially suitable for urban areas, where larval habitats are limited, particularly when applied in conjunction with IRS and other adulticidal measures, such as the use of insecticide treated bednets. [source]


Long-term landscape evolution: linking tectonics and surface processes

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 3 2007
Paul Bishop
Abstract Research in landscape evolution over millions to tens of millions of years slowed considerably in the mid-20th century, when Davisian and other approaches to geomorphology were replaced by functional, morphometric and ultimately process-based approaches. Hack's scheme of dynamic equilibrium in landscape evolution was perhaps the major theoretical contribution to long-term landscape evolution between the 1950s and about 1990, but it essentially ,looked back' to Davis for its springboard to a viewpoint contrary to that of Davis, as did less widely known schemes, such as Crickmay's hypothesis of unequal activity. Since about 1990, the field of long-term landscape evolution has blossomed again, stimulated by the plate tectonics revolution and its re-forging of the link between tectonics and topography, and by the development of numerical models that explore the links between tectonic processes and surface processes. This numerical modelling of landscape evolution has been built around formulation of bedrock river processes and slope processes, and has mostly focused on high-elevation passive continental margins and convergent zones; these models now routinely include flexural and denudational isostasy. Major breakthroughs in analytical and geochronological techniques have been of profound relevance to all of the above. Low-temperature thermochronology, and in particular apatite fission track analysis and (U,Th)/He analysis in apatite, have enabled rates of rock uplift and denudational exhumation from relatively shallow crustal depths (up to about 4 km) to be determined directly from, in effect, rock hand specimens. In a few situations, (U,Th)/He analysis has been used to determine the antiquity of major, long-wavelength topography. Cosmogenic isotope analysis has enabled the determination of the ,ages' of bedrock and sedimentary surfaces, and/or the rates of denudation of these surfaces. These latter advances represent in some ways a ,holy grail' in geomorphology in that they enable determination of ,dates and rates' of geomorphological processes directly from rock surfaces. The increasing availability of analytical techniques such as cosmogenic isotope analysis should mean that much larger data sets become possible and lead to more sophisticated analyses, such as probability density functions (PDFs) of cosmogenic ages and even of cosmogenic isotope concentrations (CICs). PDFs of isotope concentrations must be a function of catchment area geomorphology (including tectonics) and it is at least theoretically possible to infer aspects of source area geomorphology and geomorphological processes from PDFs of CICs in sediments (,detrital CICs'). Thus it may be possible to use PDFs of detrital CICs in basin sediments as a tool to infer aspects of the sediments' source area geomorphology and tectonics, complementing the standard sedimentological textural and compositional approaches to such issues. One of the most stimulating of recent conceptual advances has followed the considerations of the relationships between tectonics, climate and surface processes and especially the recognition of the importance of denudational isostasy in driving rock uplift (i.e. in driving tectonics and crustal processes). Attention has been focused very directly on surface processes and on the ways in which they may ,drive' rock uplift and thus even influence sub-surface crustal conditions, such as pressure and temperature. Consequently, the broader geoscience communities are looking to geomorphologists to provide more detailed information on rates and processes of bedrock channel incision, as well as on catchment responses to such bedrock channel processes. More sophisticated numerical models of processes in bedrock channels and on their flanking hillslopes are required. In current numerical models of long-term evolution of hillslopes and interfluves, for example, the simple dependency on slope of both the fluvial and hillslope components of these models means that a Davisian-type of landscape evolution characterized by slope lowering is inevitably ,confirmed' by the models. In numerical modelling, the next advances will require better parameterized algorithms for hillslope processes, and more sophisticated formulations of bedrock channel incision processes, incorporating, for example, the effects of sediment shielding of the bed. Such increasing sophistication must be matched by careful assessment and testing of model outputs using pre-established criteria and tests. Confirmation by these more sophisticated Davisian-type numerical models of slope lowering under conditions of tectonic stability (no active rock uplift), and of constant slope angle and steady-state landscape under conditions of ongoing rock uplift, will indicate that the Davis and Hack models are not mutually exclusive. A Hack-type model (or a variant of it, incorporating slope adjustment to rock strength rather than to regolith strength) will apply to active settings where there is sufficient stream power and/or sediment flux for channels to incise at the rate of rock uplift. Post-orogenic settings of decreased (or zero) active rock uplift would be characterized by a Davisian scheme of declining slope angles and non-steady-state (or transient) landscapes. Such post-orogenic landscapes deserve much more attention than they have received of late, not least because the intriguing questions they pose about the preservation of ancient landscapes were hinted at in passing in the 1960s and have recently re-surfaced. As we begin to ask again some of the grand questions that lay at the heart of geomorphology in its earliest days, large-scale geomorphology is on the threshold of another ,golden' era to match that of the first half of the 20th century, when cyclical approaches underpinned virtually all geomorphological work. Copyright © 2007 John Wiley & Sons, Ltd. [source]


Historical Aspects of Idiopathic Generalized Epilepsies

EPILEPSIA, Issue 2005
Peter Wolf
Summary:, Early in these proceedings, the origin of the three terms in the title, "idiopathic generalized epilepsy," is discussed with respect to their significance over time, and typical misunderstandings. In the mid-20th century, a rather chaotic use of a multitude of often loosely defined terms had developed, which increasingly became an obstacle to a meaningful international discussion. The International League against Epilepsy (ILAE) took the initiative to develop an internationally accepted terminology with a classification system consisting of a classification of seizures (1981) and a classification of syndromes (1989). The Idiopathic Generalized Epilepsies are one of its four major groups emerging from a double dichotomy of generalized versus localization-related and idiopathic versus symptomatic. The inclusion of biologic aspects such as syndrome-specific ages of onset ("age-related syndromes") or syndrome-specific relations of seizure occurrence to the sleep,wake cycle ("Epilepsy with Grand Mal on Awaking") meant that the syndrome classification merged the more biological views of the German school with the more neurophysiological ones of the French. Apart from establishing a common international language concerning epilepsy, the International Classification of Epilepsies and Epileptic Syndromes became an important stimulator of research, especially concerning the idiopathic epilepsies. In particular, genetic and functional imaging investigations aim at a better understanding of these conditions. It is now understood that most idiopathic syndromes have a,sometimes complex,genetic background, but we are also becoming aware of the inappropriateness of the time-honored term "generalized" and part of our dichotomies. Both localization-related and "generalized" idiopathic epilepsies seem to share a principle of ictogenesis based on functional anatomic pathogenic networks, and we seem to move toward understanding them as functional system disorders of the brain. [source]


Air temperatures at Armagh Observatory, Northern Ireland, from 1796 to 2002

INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 8 2005
C. J. Butler
Abstract Three independent mean temperature series for Armagh Observatory, covering the period 1796,2002 have been calibrated and corrected for the time of reading and exposure. Agreement between the three series is good in regions of overlap. With a short gap in the Armagh data from 1825 to 1833 filled by data from two stations in Dublin, the resulting series is the longest for the island of Ireland and one of the longest for any single site in the British Isles. Over the past 207 years, we note that temperatures in Armagh, in all seasons, show a gradual overall trend upwards. However, there are seasonal differences: summer and spring temperatures have increased by only half as much as those in autumn and winter. This is partly due to the exceptionally cold winters and autumns experienced prior to 1820. Relative to the overall trend, warm periods occurred in Ireland, as in other parts of Europe, in the mid-19th century, in the mid-20th century and at the end of the 20th century. Relatively cool temperatures prevailed in the early 19th century, in the 1880s and in the 1970s. Thus, if the baseline against which current temperatures are compared were moved from the late 19th century to include the earlier warm period, the apparent warming at the end of the late 20th century would be correspondingly reduced. A gradual decline in the daily temperature range at Armagh since 1844 may have resulted from higher minimum temperatures associated with increased cloudiness. A 7.8 year periodicity is identified in winter and spring mean temperatures at Armagh, which is probably a consequence of the North Atlantic oscillation. Copyright © 2005 Royal Meteorological Society [source]


Social Change and Social Policy in Japan

INTERNATIONAL JOURNAL OF JAPANESE SOCIOLOGY, Issue 1 2009
Masayuki Fujimura
Abstract This paper aims to present and discuss social change and social policy in Japan after the mid-20th century from a sociological viewpoint. Japanese social change and social policy from the mid-20th century onward can be categorized into three models in chronological order: escape from mass poverty by means of industrialization, improvement of the social security system to establish a welfare state, and parallel progress of aspiration for a welfare society and workfare. Defined concretely, these are (1) the period that established and improved social security, which started immediately after the end of World War II and ended in 1973, when Japan began to suffer from low growth after enjoying high growth; (2) the period in which finance for social security was adjusted, halfway through which the country experienced a bubble economy; and (3) the period after the 1990s, in which the structural reform of social security went hand-in-hand with labor policy and the advent of globalization. In each of the three periods, the direction of social policy was affected by factors that caused changes in such areas as industrial structure (the decline of agriculture), demographic structure (an aging society), and family structure and work pattern (the growing trend of nuclear families, single-person households, and irregular employment). In Japan, life security now attracts increasing attention, and employment security rather than social security has been the central issue. As it is greatly affected by globalization, employment security grows less conspicuous and makes the vulnerability of social security grow more conspicuous. Social policy has the potential to become an area with which to struggle for national integration and fissures between social groups. [source]


Jung's social psychological meanings

JOURNAL OF COMMUNITY & APPLIED SOCIAL PSYCHOLOGY, Issue 2 2008
Graham Richards
Abstract The latter decades of the 20th century saw C.G. Jung doubly marginalized, both by Psychology's academic establishment, for whom he was beyond the scientific pale, and by critical psychologists for whom he was, to simplify, beyond the ideological one. In this paper, I will suggest that there are two respects in which Social Psychology should reconsider his position. Firstly his own, albeit largely covert, Social Psychology, has affinities with critical Social Psychology; secondly, in the subject matter sense, Jung's own social psychological significance in the mid-20th century and beyond itself requires attention in its own right. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Progressive supranuclear palsy: New disease or variant of postencephalitic parkinsonism?

MOVEMENT DISORDERS, Issue 3 2004
Adolfo Brusa MD
Abstract We review the etiological importance of the epidemic encephalitis for progressive supranuclear palsy (PSP) and addresses the question of whether the explosion of PSP literature in the mid-20th century reflects the appearance of a new disease. We examined 2,000 studies on Parkinson's disease from 1861 to 1963 and found PSP-like cases in the past, before the epidemic encephalitis era. It can be assumed that PSP is neither a new disease nor a variant of postencephalitic parkinsonism. © 2003 Movement Disorder Society [source]


Anthropological Knowledge and Native American Cultural Practice in the Liberal Polity

AMERICAN ANTHROPOLOGIST, Issue 2 2002
Professor James P. Boggs
U.S. Indian policy is caught between two incommensurable theories or paradigms. First, liberal theory extended the worldviewof early physical science to understand human nature. Providing the conceptual foundation for liberal polities, it largely underwrote U.S. Indian policy into the mid-20th century. Liberal theory recently has been superceded, as theory, by anthropological culture theory, which better accounts for variations between peoples and the realities of human life. The advent of culture theory marks a major paradigm shift within science and public consciousness. Liberal theory, however, remains the foundation for the powerful ideology of liberalism and the institutional practices of Western capitalism and democracy. Thus arise uncomfortable disjunctions,first, between incommensurable theories that both remain vital forces in public life, and, secondarily, between knowledge and practice. This article explores these contending theoretical formations, disjunctions between them, and illustrates how these disjunctions translate into contemporary argument in U.S. Indian policy. [source]


Acute Myocardial Infarction and Acute Coronary Syndrome: Then and Now (1950,2005)

PREVENTIVE CARDIOLOGY, Issue 4 2006
Monte Malach MD
Advances in the prevention, diagnosis, and treatment of acute myocardial infarction (AMI) and acute coronary syndrome (ACS) have been remarkable since the mid-20th century. Even the clinical terminology used to describe some of the various components of ACS have undergone change, while the latter term itself represents a fairly recent addition to the medical lexicon. Although there have been dramatic changes in the diagnostic and therapeutic interventions used and impressive declines in morbidity and mortality, the differential diagnosis and complications of AMI and ACS remain as challenging now as they were a half century ago. This article presents in detail the medical understanding of AMI in the mid-20th century and how physicians of that era managed it and its complications, and contrasts this with current evidence-based knowledge and interventions. [source]


Public Health Nursing in Latin America

PUBLIC HEALTH NURSING, Issue 4 2006
Hazel O'Hara
ABSTRACT This reprint of excerpts from an article printed in Public Health Nursing in February 1950 by Hazel O'Hara, a staff writer for the Institute of Inter-American Affairs, describes the state of public health nursing in clinics operated under the cooperative health programs of the Institute of Inter-American Affairs, in conjunction with governmental entities in Latin American countries and the United States federal government in the mid-20th century. The Institute of Inter-American Affairs was an important element of Franklin D. Roosevelt's "Good Neighbor" policy toward Latin America. Conceived by Nelson Rockefeller, Assistant Secretary of State in the Roosevelt administration, the program was delayed by the outbreak of World War II (NLM, 2005, June 22). O'Hara's colorful descriptions of jungle residents and poor residents of urban slums have been omitted because they reflect a past time and sensibility. The remaining information, however, is significant in understanding the development of public health nursing in countries where it had not previously existed, the expansion of the nursing workforce, and the creation of health centers that served communities to improve social conditions as well as health status. [source]


Changing Times, Changing Needs, Changing Programs

PUBLIC HEALTH NURSING, Issue 3 2005
Article first published online: 24 JUN 200
EDITOR's NOTE, The following reprint of the unsigned editorial for the April 1952 issue of Public Health Nursing describes the historical needs and the continuing development of school health nursing from the early to mid-20th century. Twenty-first century schools continue to deal with some of the same issues such as hunger, poor nutrition, and the adverse effects of overly burdensome work schedules on adolescent health and mental well-being. The goal, so optimistically anticipated by the editors of Public Health Nursing in 1952, of continuous, well-coordinated health supervision from birth to maturity continues to elude us. Of course, school nurses and other health personnel address problems not openly discussed in the 1950s,substance abuse, violence, sexually transmitted diseases, and teen pregnancy. The theme of this historical editorial is the power of advocacy,and the responsibility public health nurses have to use our talents to improve child health. [source]


Necrosis of the long process of the incus following stapes surgery: New anatomical observations,,

THE LARYNGOSCOPE, Issue 4 2009
Imre Gerlinger MD
Abstract Objectives/Hypothesis: The most frequent complication (generally recognized during revision procedures) following seemingly successful stapedotomies and stapedectomies is necrosis of the long process of the incus. This is currently ascribed to a malcrimped stapes prosthesis or to a compromised blood supply of the incus. The two-point fixation can cause a mucosal injury with a resulting toxic reaction, and also osteoclastic activity. An important aspect in the engineering of ideal stapes prostheses is that they should be fixed circularly to the long process of the incus with appropriate strength. The objective of this study was to compare current knowledge relating to the blood supply of the ossicular chain with the present authors' observations on cadaver incudes. Most of the papers dealing with this issue appeared in the mid-20th century. Methods: The published data were compared with the authors' findings gained from photodocumentation on 100 cadaver incudes. The photos were taken with a Canon EOS 20 digital camera (Canon, Inc., Lake Success, NY) with a 5:1 macro-objective. The long processes of the incudes were examined from four directions under a Leica surface-analyzing microscope (Leica Microsystems GmbH, Wetzlar, Germany). Results: Analysis of the positions of the entrances of the feeding arteries (nutritive foramina) on the incudes revealed 1-4 nutritive foramina on the long processes of 48% (24) of the left-sided incudes and 56% (28) of the right-sided incudes. The positions of these foramina differed, however, from those previously described in the literature. They were mostly located not on the medial side of the incus body or on the short process or on the cranial third of the long processes, but antero-medially, mostly on the middle or cranial third. In 48% of all the incudes examined, an obvious foramen was not observed either in the body or in the long process of the incus. No relationship was discerned between the chronological age of the incus specimens and the numbers and/or locations of the nutritive foramina. In each case, the opening of the foramen was the beginning of a tunnel running obliquely and medially upward through the corticalis of the long process of the incus. The foramina are thought to be capable of ensuring a richer blood supply between the surface and the inside of the long process, allowing the arteries to run in and out. Conclusions: These observations indicate that conclusions drawn from classical anatomical works appear to need reconsideration. The present authors consider that the reason for the necrosis of the long process of the incus is not a compromised blood supply, except in some exceptional anatomical situations. They discuss the possible reasons why malcrimping may lead to necrosis of the long process of the incus. To prevent such malcrimping, attention is paid to the new generation of prostheses. Laryngoscope, 2009 [source]