bluuebunny/crossref_metadata_2025_split huggingface dataset:
Still Photography
Authors: Kraus Russell 
Published: October 2003

Abstract
Camera still imaging is the use of a lighttight device that holds a light‐sensitive detector and permits controlled exposure to light by using a lens that has diaphragm control and a shutter, a device that controls the length of exposure. Controlled exposure is simply taken as an amount of light during a continuous period of time that produces a desired amount of density on the film after development. The desired amount of exposure is typically determined by either experimental methods know as sensitometry or through trial and error.
The shutter range for exposure can be between several hours and 1/8000th of a second, excluding the use of a stroboscopic flash that permits exposure times shorter than a millionth of a second.
The image has a size or format of standard dimensions: 16‐mm (subminiature), 35‐mm(miniature), and 60‐mm (medium format). These are commonly referred to as roll film formats. Four inches by five inches, 5 × 7 inches, and 8 × 10 inches are three standard sheet film sizes. A view camera, monorail camera, or folding type is used to expose each sheet one at a time. Folding type, technical cameras that have a baseboard can be single sheet exposure or can adapt to a roll film back of reduced dimensions. All current camera systems can either replace their film detectors with digital detectors or themselves are replaced entirely by a digital version.
The nature of current still photography can be seen in its applied aspects: Documentary, reportage, scientific recording, commercial/ advertising, and fine art shooting are the primary realms of the professional photographer. In each activity, care is given to the materials, equipment, and processes by which a specific end is achieved. Scientific and technical photographers use the photographic process as a data collection tool where accuracy in time and space is of paramount importance. Photography for the commercial, documentary, and fine arts photographers has never been an objective and simple recording of an event or subject. This type of photography has as much purpose and artifice as commercial/advertising shooting. The visual selling of product by imagery designed to elicit an emotional response has been an integral part of advertising for more than 100 years. The psychology of photography has remained relatively the same during this time, albeit photocriticism has had many incarnations, but the technology that has made photography the tool it is has changed very rapidly and innovatively during the last century. The current digital evolution in photography will further advance the tools available and alter the way images are captured and displayed.
Tomographic Image Formation Techniques
Authors: Herman Gabor T. 
Published: October 2003

Abstract
Computerized tomography is the process of reconstructing the interiors of objects from collected data based on transmitted or emitted radiation. This article explains the nature of the reconstruction problem and present computer algorithms used for achieving the reconstructions and approaches for evaluating the efficacy of such algorithms are discussed.
This article cover some of the basic principles behind tomographic imaging, including such topics as the Radon transform, interpolation for backprojection (both modified cubic spline and sinc), the Ram–Lak filter, missing angle techniques, maximum entropy techniques, resolution, the signal‐to‐noise ratio, and artifact limitations.
Weather Radar
Authors: Rauber Robert M. 
Published: October 2003

Abstract
This article contains a brief overview of the history of meteorological radars, presents the operating principles of these radars, and explains important applications of radar in the atmospheric sciences. Meteorological radars transmit short pulses of electromagnetic radiation at microwave or radio frequencies and detect energy backscattered toward the radar's antenna by scattering elements in the atmosphere. Radiation emitted by radar is scattered by water and ice particles, insects, other objects in the path of the beam, and refractive index heterogeneities in air density and humidity. The returned signal is the combination of radiation backscattered toward the radar by each scattering element within the volume illuminated by a radar pulse. Meteorologists use the amplitude, phase, and polarization state of the backscattered energy to deduce the location and intensity of precipitation, the wind speed in the direction of the radar beam, and precipitation characteristics, such as rain versus hail.
X
‐
R
ay Telescope
Authors: Cash Webster 
Published: October 2003

Abstract
An X‐ray telescope is an optic that is used to focus and image x‐rays in the manner of a conventional telescope for visible light astronomy. X‐ray telescopes are exclusively the domain of X‐ray astronomy, the discipline that studies high energy emissions from objects in space. A telescope, by its very nature, is for studying objects at large distances, concentrating their radiation, and magnifying their angular extent. Since X‐rays cannot travel large distances through the atmosphere of the Earth, their function can only be used in spacecraft, observing targets through the vacuum of space.
X‐rays penetrate matter and are used for imaging of the interior of the human body. Unfortunately, this means that X‐rays also tend to penetrate telescope mirrors, making the mirror worthless for astronomy. But, by use of a specialized technique called grazing incidence, telescopes can be made to reflect, and astronomy can be performed. In this article, we describe the basic techniques used to build x‐ray telescopes for X‐ray astronomy.
X‐ray astronomy, because it must be performed above the atmosphere, is a child of the space program. Telescopes are carried above the atmosphere by rockets and used to study the Sun, the planets, and objects in the depths of space. These telescopes have provided a different view of the hot and energetic constituents of the universe, and produced the key observations to establish the existence of black holes.
Various telescopes are described, e.g., Thin mirror telescopes, Kirk‐Baez telescopes, X‐ray interferometric telescopes, and Multilayer telescopes. Various missions involving these telescopes are discussed.
Acoustic Sources or Receiver Arrays
Authors: Thompson William 
Published: October 2003

Abstract

This article discusses the directional response characteristics (i.e., the beam patterns or directivity patterns) of arrays of time harmonic acoustic sources. A wonderful consequence of the acoustic reciprocity theorem, however, is that the directional response pattern of a transducer used as a source is the same as its directional response pattern used as a receiver. The arrays in question begin with the simplest, two identical point sources, and build up to line arrays that contain many point sources, continuous two dimensional arrays of sources, and discrete arrays of finite sized sources. Topics such as beam width of the main lobe, amplitudes of the side lobes, amplitude weighting to reduce the side lobes, and beam tilting and its consequences are discussed. Again, although the emphasis will be on the response of arrays of sources, the result (the directivity pattern) is the same for the same array used as a receiver. Harmonic time dependence of the form exp(
j
ω
t
) at circular frequency ω is assumed and suppressed throughout most of the following discussion.
Television Broadcast Transmission Standards
Authors: Godger Alan S. , Redford James R. 
Published: October 2003

AbstractSince the invention of television, the images and sound have been captured, processed, transmitted, received, and displayed using analog technology, where the picture and sound elements are represented by signals that are proportional to the image amplitude and sound volume.More recently, as solid‐state technology has developed, spurred primarily by the development of computers, digital technology has gradually been introduced into handling the television signal, both for image and sound. The digital electric signal representing the various elements of the image and sound is composed of binary numbers that represent the image intensity, color, and so on, and the sound characteristics.Many portions of television systems are now hybrid combinations of analog and digital, and it is expected that eventually all television equipment will be fully digital, except for the transducers, cameras, and microphones (whose inputs are analog) and the television displays and loudspeakers (whose outputs are analog).The currently used broadcast television transmission standards [National Television Systems Committee (NTSC), phase alternate line (PAL) and sequential and memory (SECAM)] for 525‐ and 625‐line systems were designed around analog technology, and although significant portions of those broadcast systems are now hybrid analog/digital or digital, the “over the air” transmission system is still analog. Furthermore, other than for “component” processed portions of the system, the video signals take the same “encoded” form from studio camera to receiver and conform to the same standard.The recently developed ATSC Digital Television Standard, however, uses digital technology for “over the air” transmission, and the digital signals used from the studio camera to the receiver represent the same image and sound, but differ in form in portions of the transmission system. This variation is such that in the studio, maximum image and sound information is coded digitally, but during recording, special effects processing, distribution around a broadcast facility, and transmission, the digital signal is “compressed” to an increasing extent as it approaches its final destination at the home. This permits practical and economical handling of the signal.
Terahertz Electric Field Imaging
Authors: Zhang X.‐C. 
Published: October 2003

AbstractVarious frequencies are spaced along the frequently used electromagnetic spectrum, including microwaves, infrared, visible light, and X rays. Terahertz radiation between microwave and infrared frequencies lies. In the electromagnetic spectrum, radiation at 1 THz has a period of 1 ps, a wavelength of 300 µm, a wave number of 33 cm−1, photon energy of 4.1 meV, and an equivalent temperature of 47.6 K. In the same way that visible light can create a photograph, radio waves can transmit sound, and X rays can see shapes within the human body, terahertz waves (Trays) can create pictures and transmit information.Until recently, however, the very large terahertz portion of the spectrum has not been particularly useful because there were neither suitable emitters to send out controlled terahertz signals nor efficient sensors to collect them and record information. Recent developments in terahertz time‐domain spectroscopy and related terahertz technologies now lead one to view the world in a new way. As a result of developing research, terahertz radiation now has widespread potential applications in medicine, microelectronics, agriculture, forensic science, and many other fields.Three properties of THz wave radiation triggered research to develop this frequency band for applications and are discussed.Coherent terahertz time‐domain spectroscopy that has an ultrawide bandwidth provides a new method for characterizing the electronic, vibronic, and compositional properties of solid, liquid, and gas phase materials, as well as flames and flows. In theory, many biological and chemical compounds have distinct signature responses to terahertz waves due to their unique molecular vibrations and rotational energy levels, this implies that their chemical compositions might be examined using a terahertz beam.A T‐ray imaging modality would produce images that have “component contrast” enabling analysis of the water content and composition of tissues in biological samples. Such capability presents tremendous potential to identify early changes in composition and function as a precursor to specific medical investigations and treatment. Moreover, in conventional optical transillumination techniques that use near‐infrared pulses, large amounts of scattering can spatially smear out the objects to be imaged. T‐ray imaging techniques, due to their longer wavelengths, can provide significantly enhanced contrast as a result of low scattering (Rayleigh scattering).
Hybrid Semiconductor Pixel Detectors for Low‐ and Medium‐EnergyX‐ and Gamma‐Ray Single Photon Imaging Using the Medipix Read‐Out Chip
Authors: Russo Paolo 
Published: October 2003

AbstractAfter a brief description of microstrip and pixel detectors for radiation imaging with X‐rays and gamma‐rays, the functionality, physical response, and imaging performance of the hybrid pixel detectors based on the Medipix1 photon counting chip for such diverse imaging applications such as digital mammography, synchrotron X‐ray radiation, nuclear medicine, and so on are described. It is concluded that such hybrid pixel detectors, originated from high‐energy physics, have great potential for specific scientific and industrial X‐ and gamma‐ray imaging applications and that the fabrication of large detector arrays or mosaic of detectors for large area imaging is still the main open problem with hybrid detectors.
Pharmacogenetics and mood stabilization in bipolar disorder
Authors: Ruzickova Martina , Turecki Gustavo , Alda Martin 
Published: October 2003

AbstractBipolar disorder is a severe psychiatric disease characterized by varying treatment response among individual patients. Effects of certain treatments, for instance, lithium, can be predicted from clinical characteristics of patients and their family histories. This led to a suggestion that a treatment response could identify subtypes of bipolar disorder particularly suited for gene‐mapping studies. In this paper we review family and molecular studies of bipolar disorder responsive to lithium, as well as studies aiming to identify polymorphisms associated with the treatment response itself. While molecular genetic research and gene expression studies promise to bring new insights into the pathophysiology of the illness and the nature of treatment response, and thus provide new information for better treatment of bipolar disorder in the future, results from family studies and studies of clinical correlates of treatment response may already be utilized in the management of bipolar disorder. © 2003 Wiley‐Liss, Inc.
Studies of offspring of parents with bipolar disorder
Authors: Chang Kiki , Steiner Hans , Ketter Terence 
Published: October 2003

AbstractChildren and adolescents who are the biological offspring of individuals with bipolar disorder (BD) (bipolar offspring) represent a population rich in potential for revealing important aspects in the development of BD. Multiple cross‐sectional assessments of psychopathology in bipolar offspring have confirmed high incidences of BD, as well as mood and behavioral disorders, and other psychopathology in this population. Longitudinal studies of offspring have begun to shed light on precursors of BD development. Other assessments of bipolar offspring have included dimensional reports of psychiatric and psychosocial functioning, temperament assessments, and descriptions of family environments and parenting styles. Neurobiological studies in bipolar offspring are just beginning to yield findings that may be related to the underlying neuropathophysiology of BD. The future holds promise for longitudinal studies of bipolar offspring incorporating all of these facets, including genetic analyses, to further elucidate the factors involved in the evolution of BD. © 2003 Wiley‐Liss, Inc.
Genetic linkage and association studies in bipolar affective disorder: A time for optimism
Authors: Schulze Thomas G. , McMahon Francis J. 
Published: October 2003

AbstractGenetic research on complex diseases is beginning to bear fruit, with the successful identification of candidate susceptibility genes in diabetes, asthma, and other illnesses. Similar success is on the horizon for bipolar affective disorder (BPAD), but significant challenges remain. In this review, we outline the basic concepts of linkage and association mapping for complex phenotypes. We point out important caveats inherent in both approaches, and review guidelines on the interpretation of linkage statistics and significance thresholds. We then apply these concepts to an evaluation of the present status of genetic linkage and association studies in BPAD. The challenges posed by locus heterogeneity, phenotype definition, and sample size requirements are given a detailed treatment. Despite these challenges, we argue that the way ahead remains firmly rooted in linkage studies, complemented by association studies in linked regions. This is the only truly genome‐wide approach currently available; it has succeeded in other complex phenotypes, and it is the surest strategy for mapping susceptibility genes in BPAD. Once these genes are identified, genetic mapping methods will yield to the other methods of 21st‐century molecular biology as we begin to elucidate the pathophysiology of BPAD. © 2003 Wiley‐Liss, Inc.
Reoperations after prophylactic mastectomy with or without implant reconstruction
Authors: Zion Sara M. , Slezak Jeffrey M. , Sellers Thomas A. , Woods John E. , Arnold Phillip G. , Petty Paul M. , Donohue John H. , Frost Marlene H. , Schaid Daniel J. , Hartmann Lynn C. 
Published: October 2003

AbstractBACKGROUNDThe authors characterized the unanticipated reoperations after prophylactic mastectomy, with or without implant reconstruction.METHODSThe surgical cohort was comprised of 1417 women with a family history of breast carcinoma. The women received a prophylactic mastectomy with (bilateral,n= 593; contralateral,n= 506) or without reconstruction (n= 318) at the Mayo Clinic (Rochester, MN) between 1960 and 1993. Reoperations and indications for reoperation were compiled from medical records and a patient survey.RESULTSThree hundred eighteen women received a bilateral (n= 39) or contralateral (n= 279) prophylactic mastectomy without reconstruction. With a median follow‐up of 15 years, 18 women (6%) required reoperation. Most of these reoperations occurred within the first year after prophylactic mastectomy. Five hundred ninety‐three women had reconstruction with implants following bilateral propylactic mastectomy. Approximatelyone‐half of the women (52%) required at least 1 unanticipated reoperation during a median follow‐up of 14 years. Approximately 39% of all reoperations occurred within 1 year of breast reconstruction and 69% within 5 years. Implant‐related issues were the most common cause for reoperation. Some women with breast carcinoma elected to receive contralateral prophylactic mastectomy with therapeutic mastectomy for the affected breast. Five hundred six women received reconstruction with implants. During a median follow‐up of 8.8 years, 189 women (37%) required unanticipated reoperation. The most common indication was implant‐related issues. The time course of reoperations was similar to that for women in the bilateral group.CONCLUSIONSSurgical reoperations were fairly common among women who received prophylactic mastectomy with implant reconstruction. Most of the reoperations were implant related. Reoperations were fairly uncommon after prophylactic mastectomy without reconstruction. Cancer 2003. © 2003 American Cancer Society.
The relevance of occult axillary micrometastasis in ductal carcinoma in situ
Authors: Lara Jonathan F. , Young Steven M. , Velilla Rowena E. , Santoro Elissa J. , Templeton Sandra F. 
Published: October 2003

AbstractBACKGROUNDDuctal carcinoma in situ (DCIS) represents 20% of newly diagnosed breast carcinoma cases. Historically, the incidence of axillary metastasis in DCIS has been small (1–2%) and its significance has been debated. It is widely known that serial sections of lymph nodes coupled with keratin immunohistochemistry (IHC) increases identification of micrometastasis. The advent of sentinel lymph node evaluation underscores the need to reevaluate the significance of occult micrometastases in DCIS.METHODSPatients with DCIS and negative axillary lymph nodes from 1974 to 1992 were selected from the Saint Barnabas Medical Center Tumor Registry. All diagnoses were confirmed, and paraffin blocks were retrieved after acceptance into the study. Seven serial sections were obtained from each block and evaluated with two cytokeratin IHC stains. Clinical follow‐up ranged from 10 to 28 years.RESULTSOne hundred two patients were included in the study. Micrometastases were identified in 13 patients (13%), mostly on 1 level and composed of microscopic clusters in the subcapsular sinus. Seven of these lymph node–positive patients (58%) had high‐grade comedo DCIS, 4 (33%) had intermediate grades of various types of DCIS, and one had a low‐grade micropapillary DCIS. The overall disease recurrence rate was 12%, but micrometasis was not detected in any of the patients who developed disease recurrence.CONCLUSIONSSerial IHC evaluation of lymph nodes dramatically increased the identification of occult micrometastasis. However, IHC detected micrometastasis has no apparent clinical significance in DCIS, based on the current long‐term clinicopathologic study. Therefore, the authors questioned the significance of occult micrometastasis, identified by IHC, in DCIS of any type and extent. Further evaluation and follow‐up of lymph node micrometastases in patients with invasive tumors of various sizes are needed. The current findings would not support altering the stage of patients with DCIS and micrometastasis detected by IHC only. Cancer 2003. © 2003 American Cancer Society.
Detection of recurrent oral squamous cell carcinoma by [18F]‐2‐fluorodeoxyglucose‐positron emission tomography
Authors: Kunkel Martin , Förster Gregor J. , Reichert Torsten E. , Jeong Jong‐Hyeon , Benz Peter , Bartenstein Peter , Wagner Wilfried , Whiteside Theresa L. 
Published: October 2003

AbstractBACKGROUNDPatients with recurrent oral squamous cell carcinoma (OSCC) have a dismal prognosis and represent a therapeutic challenge. A positron emission tomography (PET) scan with [18F]‐2‐fluorodeoxyglucose ([18F]FDG) can improve early cancer detection. The current study evaluates the prognostic value of [18F]FDG‐PET scan in patients with recurrent OSCC.METHODSThe authors studied 97 patients with previously resected OSCC who were restaged by PET scanning. Of the 97 patients, 64 had no evidence of clinical disease and 33 were suspected of having disease by imaging, clinical findings, or pathologic evaluation. The median follow‐up period was 35.4 months after a PET scan. The end points included disease recurrence, a disease recurrence‐free period 6 months after a PET scan, or death.RESULTSThe overall sensitivity of a PET scan did not exceed 90% and its specificity varied from 67% for local disease recurrence/second primaries to 99% for lymph node metastasis. Increased [18F]FDG uptake predicted increased hazard of death (hazard ratio: 6.83; P = 0.00034) and proved to be a highly predictive marker of disease status. A significant association was established for incremental standardized uptake values and 3‐year patient survival (P=0.0089), indicating that intense glucose metabolism in the tumor is a negative marker of survival in recurrent OSCC. Overall, survival was longer in patients with a negative rather than a positive PET scan (P < 0.00001).CONCLUSIONSPET scanning was found to be highly valuable for diagnosing OSCC recurrence in a postoperative setting. It provided prognostic information and played an important role in patient counseling and management. Cancer 2003. © 2003 American Cancer Society.