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1.
Proc Biol Sci ; 287(1931): 20200922, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-33043867

RESUMO

Most of the world's crops depend on pollinators, so declines in both managed and wild bees raise concerns about food security. However, the degree to which insect pollination is actually limiting current crop production is poorly understood, as is the role of wild species (as opposed to managed honeybees) in pollinating crops, particularly in intensive production areas. We established a nationwide study to assess the extent of pollinator limitation in seven crops at 131 locations situated across major crop-producing areas of the USA. We found that five out of seven crops showed evidence of pollinator limitation. Wild bees and honeybees provided comparable amounts of pollination for most crops, even in agriculturally intensive regions. We estimated the nationwide annual production value of wild pollinators to the seven crops we studied at over $1.5 billion; the value of wild bee pollination of all pollinator-dependent crops would be much greater. Our findings show that pollinator declines could translate directly into decreased yields or production for most of the crops studied, and that wild species contribute substantially to pollination of most study crops in major crop-producing regions.


Assuntos
Agricultura , Produtos Agrícolas , Polinização , Animais , Abelhas , Abastecimento de Alimentos , Estados Unidos
2.
Semin Roentgenol ; 32(1): 12-24, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9035274

RESUMO

CR has emerged as a general imaging technology for successful imaging of the chest, abdominal, musculoskeletal, and pediatric anatomy. For the general radiographer, CR is both celebrated and scorned for its complex function, and requires thorough ongoing training for the technologists to produce consistently high image quality. Digital radiography's unique separation of detector, display, and archive add a flexibility over screen-film technology for moving, storing, printing, and viewing plain radiographic images. CR technology is now a viable solution for those wishing to embrace the electronic and digital revolution in medicine. Although the system has less spatial resolution than screen-film technology, the strength of postacquisition image processing to enhance pathology and view obscured anatomy makes CR imaging attractive to technologists and radiologists. CR is a new modality for the general radiographer that, when put into the hands of a well-trained technologist, produces images of beautiful diagnostic quality.


Assuntos
Intensificação de Imagem Radiográfica , Sistemas de Informação em Radiologia , Humanos , Processamento de Imagem Assistida por Computador , Tecnologia Radiológica
3.
Semin Roentgenol ; 32(1): 25-37, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9035275

RESUMO

Image processing is a critical part of obtaining high-quality digital radiographs. Fortunately, the user of these systems does not need to understand image processing in detail, because the manufacturers provide good starting values. Because radiologists may have different preferences in image appearance, it is helpful to know that many aspects of image appearance can be changed by image processing, and a new preferred setting can be loaded into the computer and saved so that it can become the new standard processing method. Image processing allows one to change the overall optical density of an image and to change its contrast. Spatial frequency processing allows an image to be sharpened, improving its appearance. It also allows noise to be blurred so that it is less visible. Care is necessary to avoid the introduction of artifacts or the hiding of mediastinal tubes.


Assuntos
Intensificação de Imagem Radiográfica , Humanos , Processamento de Imagem Assistida por Computador , Intensificação de Imagem Radiográfica/métodos
4.
Semin Roentgenol ; 32(1): 38-44, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9035276

RESUMO

Digital radiography is an appropriate method for both bedside and in-department chest radiographs. Its major advantage in bedside chest radiography is its control of the displayed optical density of these radiographs. With dynamic range control processing, it improves the visibility of tubes and lines superimposed on the mediastinal tissues. When used for in-department chest radiography, it may offer slight advantages in the evaluation of disease in the mediastinum, but in general is equivalent to film-screen chest radiography. The main reasons for using digital chest radiography for in-department chest radiographs relate mainly to its use as a data entry point method of projection radiography for high-quality teleradiology or for its use in a picture archiving and communication system. Apart from these advantages, there is no reason to change from conventional to digital chest radiographs. Digital radiographs are, with certain systems, printed at smaller than life size. Because of this, there is a necessary period of learning as radiologists adjust to the new image size. The most important change in radiologists' work pattern appears to be the need to sit closer to the film. Findings of disease are smaller, but, with experience, just as easy to see.


Assuntos
Intensificação de Imagem Radiográfica , Radiografia Torácica , Humanos , Pneumopatias/diagnóstico por imagem
5.
Crit Rev Diagn Imaging ; 38(1): 89-113, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9063622

RESUMO

Digital mammography is a rapidly developing technology that has great potential to improve upon and ultimately replace conventional film-screen mammography for the early detection of breast cancer. This article reviews current progress in digital mammographic systems, computer-aided diagnostic programs, and artificial neural networks. Digital mammographic systems are currently in an investigational phase only. Large-scale clinical trials are needed in all areas of digital mammography before this exciting new technology can be implemented outside of research centers.


Assuntos
Mamografia , Intensificação de Imagem Radiográfica , Interpretação de Imagem Radiográfica Assistida por Computador , Inteligência Artificial , Feminino , Humanos , Redes Neurais de Computação
6.
W V Med J ; 88(4): 142-6, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1615640

RESUMO

The distribution of mammography machines and related resources in West Virginia, along with the distribution of breast cancer screen-eligible women, are examined using county-specific data. This data placed on a state map shows that it is not necessary to cross more than one county line anywhere within West Virginia in order to visit a mammography facility. The overall density of these machines is 20 per 100,000 women over 45, almost double the capacity needed for screening mammography. After taking into account the projected demand for mammography, the current average cost per exam is around $65-$100. If mammography machines were placed in all the counties without machines, the cost in those countries would be around $140 per exam. It would be cheaper to provide a travel allowance to women in rural counties than to install machines in these areas. Machines that are accredited by the American College of Radiologists, the most available indicator of quality mammography, are located only in densely populated areas of the state.


Assuntos
Centros Comunitários de Saúde/provisão & distribuição , Equipamentos e Provisões Hospitalares/provisão & distribuição , Mamografia/instrumentação , Serviço Hospitalar de Radiologia/economia , Tecnologia Radiológica/instrumentação , Acreditação/legislação & jurisprudência , Idoso , Centros Comunitários de Saúde/economia , Equipamentos e Provisões Hospitalares/economia , Feminino , Humanos , Mamografia/economia , Pessoa de Meia-Idade , Tecnologia Radiológica/economia , West Virginia , Recursos Humanos
7.
South Med J ; 85(3): 317-8, 1992 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1546357

RESUMO

The unusual soft tissue tumor we have described may be the largest yet reported. The tumor was considered benign, and its histologic features were most consistent with fibromatosis arising in a region that had been previously traumatized. Although the patient is doing well, it is premature (2 years later) to conclude that the tumor will not recur.


Assuntos
Neoplasias de Tecidos Moles/etiologia , Neoplasias Torácicas/etiologia , Ferimentos por Arma de Fogo/complicações , Adolescente , Fasciite/patologia , Feminino , Fibroma/patologia , Humanos , Neoplasias de Tecidos Moles/patologia , Neoplasias Torácicas/patologia
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