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PubMed1998

Effects of projection geometry and number of projections on accuracy of depth discrimination with tuned-aperture computed tomography in dentistry.

OBJECTIVE: The purpose of this study was to determine the degree to which the number and angular disparity of component projections influence depth discrimination with tuned-aperture computed tomography. STUDY DESIGN: Groups of three tiny steel spheres served as fiducial references on and in four partially edentulous mandibles. Two spheres were attached to the facial and lingual surfaces of each mandible, and the third was fixed in the apical region of an open tooth socket. Errors in estimates of the depth of the apically positioned sphere relative to the other two spheres were determined from three-dimensional tuned-aperture computed tomography reconstructions. These data were compared with actual measurements produced independently with an optical micrometer. Multiple projections required by the tuned-aperture computed tomography reconstruction algorithm were produced from radially symmetric exposures bearing angular disparities of 5, 15, 30, and 45 degrees. The number of symmetrically dispersed projections per tuned-aperture computed tomography reconstruction likewise was varied systematically (2, 4, 8, 12, and 16 projections). These variables were manipulated through the use of a balanced factorial design. Depth estimates were performed by trained observers; the estimates were based on the determination of tuned-aperture computed tomography slices perceived as imaging the respective apical spheres in sharpest focus. Specimen and observer effects were also considered as independent variables. Resulting data were normalized by logarithmic transformation and analyzed statistically by analysis of variance. RESULTS: Significant differences (p < 0.005) were demonstrated for angular disparity and specimen effects, but the number of projections and the effect of the observer were not found to be statistically significant. CONCLUSIONS: In dentistry, angular disparities of 15 degrees or greater should be used when tuned-aperture computed tomography is being applied to diagnostic tasks requiring maximal depth discrimination accuracy.

Algorithms↗

PubMed2004

Back-calculation and projection of the HIV/AIDS epidemic among homosexual/ bisexual men in three European countries: evalution of past projections and updates allowing for treatment effects.

This study critically evaluates the quality of 1990 back-calculations and long-term projections of the HIV/AIDS epidemic for homosexual/bisexual men in France, the Federal Republic of Germany, and the UK. The projection captured the general pattern observed in all three countries although the observed AIDS incidence peaked 2-3 years later and declined faster than had been projected. Total AIDS incidences from 1989 to 2000 were overestimated by 38.5% in France, and underestimated by 23.9 and 17.5% in western Germany and the UK. Updated back-calculations and projections to 2020 use AIDS incidence data up to 2000. The procedure incorporates an asymmetric long-tailed cumulative HIV curve as well as the increase in the median incubation period brought about by new therapies introduced during the 1990s. The results suggest that: (i) The rapid decrease in cases during the late 1990s was caused by a median incubation period that increased from 10 years to 21-23 years by the late 1990s. (ii) An imminent bottoming out followed by a protracted increase in AIDS cases from 2000 to at least 2010 could be the consequence of a leveling off of the median incubation period. (iii) A low variant of the projections shows that at least 40,000 homosexual men could develop AIDS in the three countries after 2000.

Acquired Immunodeficiency Syndrome↗

PubMed1999

A comparison of pre-Project 2000 and Project 2000 nurses' perceptions of their research training, research needs and of their use of research in clinical areas.

Most of the literature on the research training and education of nurses has focused on teaching strategies. Only a few authors have assessed systematically the impact of research modules or courses on the knowledge and attitudes of nurses. There is a lack of research on nurses' use of research following their preparation. This paper reports on some of the data from a large-scale survey of the utilization of research among nurses in Northern Ireland. In particular, a comparison is made of the perceptions of pre-Project 2000 and Project 2000 qualified nurses of their research training, research needs, and use of research in clinical areas. A questionnaire was distributed to a convenience sample of 2600 nurses from 23 hospitals in 14 Trusts in Northern Ireland. The response rate was 52.6% (n = 1368). The findings show, among others, a shortfall in research preparation of pre-Project 2000 nurses in important aspects of research. While Project 2000 nurses reported receiving more training, they did not report higher rates of research utilization than pre-Project 2000 nurses. Registered mental nurses (RMNs) and registered nurses mental handicap (RNMHs) also reported lower rates of research utilization than registered general nurses (RGNs), despite reporting the same amount of research preparation as RGNs. The implications of these findings are discussed.

Curriculum↗

PubMed2002

The neglected constituent of the basal forebrain corticopetal projection system: GABAergic projections.

At least half of the basal forebrain neurons which project to the cortex are GABAergic. Whilst hypotheses about the attentional functions mediated by the cholinergic component of this corticopetal projection system have been substantiated in recent years, knowledge about the functional contributions of its GABAergic branch has remained extremely scarce. The possibility that basal forebrain GABAergic neurons that project to the cortex are selectively contacted by corticofugal projections suggests that the functions of the GABAergic branch can be conceptualized in terms of mediating executive aspects of cognitive performance, including the switching between multiple input sources and response rules. Such speculations gain preliminary support from the effects of excitotoxic lesions that preferentially, but not selectively, target the noncholinergic component of the basal forebrain corticopetal system, on performance in tasks involving demands on cognitive flexibility. Progress in understanding the cognitive functions of the basal forebrain system depends on evidence regarding its main noncholinergic components, and the generation of such evidence is contingent on the development of methods to manipulate and monitor selectively the activity of the GABAergic corticopetal projections.

Animals↗

PubMed2000

EPR imaging from projections: errors due to misalignment of projection centres and their rectification by a novel acquisition modality.

Continuous wave and pulsed wave electron paramagnetic resonance imaging (EPRI) makes use of classical methods of acquisition of projections. Acquisition/reconstruction techniques, such as spin-echo, gradient-echo, etc, cannot be applied to EPRI because they would require very short switching times for the gradient coils. Due to the use of the polar acquisition technique, it is necessary to define a centre of rotation about which the measured projections are rotated during the reconstruction process. This centre represents the point at which the field gradient coils must produce zero magnetic field. Due to the presence of a magnetic field control system that serves to compensate for field variations, principally due to heating, some interference can occur in the control system between the main magnetic field and the magnetic field produced by the gradient coils. The effect changes as the orientation changes. This results in a shift of the centres of the projections as a function of the variation of magnetic field produced by the gradient coils on the control Hall probe. If this condition is present, some artefacts can appear on the reconstructed image. This effect is irrelevant when EPR is used for imaging of paramagnetic probes whose linewidths are of the order of 10(-4) T, while it can be significant in the case of linewidths of the order of 10(-5) T or lower or when EPR is used in microimaging applications (i.e. for high values of magnetic field gradient). We describe the effects that misalignments of the projections have on the reconstructed images. We present a useful method for estimating the real position of the centre and correcting the measured projections before the application of the reconstruction algorithm. Moreover, we demonstrate the functioning of our technique by presenting some examples of EPR reconstruction collected by an X-band EPR imaging apparatus.

Algorithms↗

PubMed2006

Building the evidence base for effective tobacco control policies: the International Tobacco Control Policy Evaluation Project (the ITC Project).

The Framework Convention on Tobacco Control (FCTC) is a seminal event in tobacco control and in global health. Scientific evidence guided the creation of the FCTC, and as the treaty moves into its implementation phase, scientific evidence can be used to guide the formulation of evidence-based tobacco control policies. The International Tobacco Control Policy Evaluation Project (ITC Project) is a transdisciplinary international collaboration of tobacco control researchers who have created research studies to evaluate and understand the psychosocial and behavioural impact of FCTC policies as they are implemented in participating ITC countries, which together are inhabited by over 45% of the world's smokers. This introduction to the ITC Project supplement of Tobacco Control presents a brief outline of the ITC Project, including a summary of key findings to date. The overall conceptual model and methodology of the ITC Project--involving representative national cohort surveys created from a common conceptual model, with common methods and measures across countries--may hold promise as a useful paradigm in efforts to evaluate and understand the impact of population-based interventions in other important domains of health, such as obesity.

Evidence-Based Medicine↗

PubMed1978

Two projection computed tomography: the axial and Towne projections.

It is occasionally necessary in evaluating lesions around the third ventricle and posterior fossa to supplement the axial view with another projection. The authors have routinely used the coronal projection as a second projection. However, the Towne view for computed tomography can be used as a second projection instead of the coronal; it is technically easier and faster to perform than the coronal projection, and provided good evaluation of the posterior fossa and para third ventricular areas in children.

Cerebral Ventricle Neoplasms↗

PubMed1981

Organization of projections from the gracile, medial cuneate and lateral nuclei in the North American opossum. Horseradish peroxidase study of the cells projecting to the cerebellum, thalamus and spinal cord.

Using the horseradish peroxidase technique on the North American opossum, we were able to locate the neurons within the dorsal column and lateral cuneate nuclei which innervate the cerebellum and thalamus as well as those within the dorsal column nuclei which project spinalward. The medial and lateral cuneate nuclei supply axons to the anterior lobe, the paramedian lobule and the pyramis of the cerebellum and the lateral nucleus provides an additional projection to the uvula. The cerebellar projections from these nuclei arise from neurons located rostral to the obex. The thalamic projections from the gracile and medial cuneate nuclei originate from neurons throughout their rostral to caudal extent, although most of them are located just rostral to the obex. Neurons within the lateral cuneate nucleus which innervate the thalamus are found at intermediate rostrocaudal levels where most of them approximate the medial cuneate nucleus. The medial cuneate also projects to at least lumbar levels of the spinal cord in the opossum and neurons giving rise to such connections are found at the level of the obex and caudal to it. Neurons within the dorsal part of the dorsal column nuclei were labelled only after thalamic injections. Our results in the opossum are compared with those obtained in several placental mammals.

Animals↗

PubMed1989

[Afferent projections to the uvula in the cat. II. Mossy fiber projections].

The mossy fiber projections to the uvula of the cerebellum were studied by means of retrograde axonal transport of horseradish peroxidase (HRP) in the cat. Following large and small injections into the uvula, distribution of the labeled cells in the brainstem nuclei was investigated. The results showed different afferent projections between the dorsal and ventral uvula. Major sources projecting to the dorsal uvula were the peduncular, paramedian, and lateral nuclei of the pontine nuclei. Labeled cells found in the pontine nuclei amounted to 81.6% of the total number of labeled cells in cat 1. On the other hand, major sources projecting to the ventral uvula were the caudal aspect of the medial and inferior vestibular nuclei, the x- and f-groups of the vestibular nuclei, the dorsal and central aspect of the superior vestibular nucleus, the rostral dorsomedial aspect of the paramedian nucleus of the pontine nuclei, the caudal aspect of the prepositus hypoglossal nucleus, and the infratrigeminal nucleus. Labeled cells in the vestibular nuclei amounted to 72.1% of the total number of the labeled cells in the cat 40. It was revealed that the lateral aspect of the ventral uvula receives inputs from the pontine nuclei, whereas the medial part of the ventral uvula receives inputs from the vestibular nuclei. Mediolateral differences were not found in the dorsal uvula. These mossy fiber zones were mediolaterally wide, and the dorsal uvula was different from the ventral uvula with regard to mossy fiber projection.

Afferent Pathways↗

PubMed1994

[Afferent projections to the nodulus in the cat. II. Mossy fiber projections].

Mossy fiber projections to the nodulus of the cerebellum were studied by retrograde axonal transport of horseradish peroxidase (HRP) in the cat. Following large and small injections into the nodulus, the distribution of labeled cells in the brainstem nuclei was investigated. Our observations provided evidence that the nodular afferents take their major origin from the medial, inferior and superior vestibular nuclei. On the other hand, minor sources projecting to the nodulus were from the x- and z-group. Of the perihypoglossal nuclei, it is only the prepositus hypoglossal nucleus which appears to be interconnected with the nodulus. There were no projections of the pontine nuclei and the nucleus reticularis tegmenti pontis to the nodulus. Injections of the nodular cortex revealed a distinct bilateral projection to this cortical area. The results showed no different projections between the dorsal and ventral nodulus. Mediolateral differences were not found in the nodulus.

Animals↗

PubMed1998

[Cognitive impairment and cardiovascular disease risk factors. Project CASCADE Kraków. I. Project to test exposure to risk factors for cardiovascular disease in the studied sample].

Dementia is found in a small percent of general population but remains a significant problem in the elderly population. Little is known whether prevention of dementia in the elderly is possible. Some evidence exists that both vascular dementia and Alzheimer's type dementia are related to cardiovascular disease risk factors. The main goal of the CASCADE Kraków Project is to study the relation between the exposure to cardiovascular disease risk factors in the middle age and cognitive impairment and cerebral white matter lesions in old age. Project CASCADE Kraków is an independent part of the international project CASCADE, which is carried out in 11 research centres from 9 countries. Polish part of the study includes a longitudinal observation of the sample screened earlier in POL-MONICA Kraków Project, which was selected from population of residents of rural province (Tarnobrzeg Voivodship). Studied sample are 1318 persons, for whom cardiovascular disease risk factors were measured in 1983-84 and who completed at least 64 years in 1997. Two-stage examination was designed. In the first stage collection of the following data was designed: socio-economic factors, history of cardiovascular disease, perceived health, blood pressure and cognitive function assessment using Mini-Mental State Examination (MMSE) procedure. In the second stage (sub-sample of 300 persons included) the following procedures were designed: detailed neuro-psychological testing, neurolo-gical examination, MRI, determination of total- and HDL-cholesterol and determination of apoE isoforms. There were 625 (47%) men and 693 (53%) women selected for the first stage. Out of them 128 (43%) men and 172 (57%) women were selected for the second stage. There were no important differences in age, education, health status and exposure to cardiovascular disease risk factors between the studied groups in the baseline assessment. However, there were important differences between men and women. Compared to men, women had lower education (higher than elementary education in 17% and 9% respectively), more frequent obesity (respectively 12% and 36%), hypertension (respectively 57% and 71%) and hyperlipoproteinemia (respectively 17% and 30%) but lower smoking rate (respectively 53% and 4%). Integration of neuropsychological testing and neuroimaging with the epidemiological approach to risk factors could contribute to better understanding of the mechanisms on which the disease affects the brain morphology and functions. The results of CASCADE and CASCADE Kraków projects will contribute also to the development of the strategies of medical care and management of the cognitive impairment in the elderly.

Aged↗

PubMed2004

Project ENABLE: a palliative care demonstration project for advanced cancer patients in three settings.

At the end of the 1990s, based on data from two major studies of end-of-life (EOL) care, the Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatment (SUPPORT), and the Hospitalized Elderly Longitudinal Project (HELP), a consensus panel report documented the problems and needs of patients with cancer and other life-limiting diagnoses at end-of-life. A national program of The Robert Wood Johnson Foundation (RWJF), Promoting Excellence in End-of-Life Care, attempted to address these needs by funding demonstration projects to test various approaches to improve identified deficits. In 1998, Project ENABLE (Educate, Nurture, Advise Before Life Ends), one of four RWJF-funded cancer center/hospice collaborations of the Promoting Excellence program, began to address these issues. The jointly sponsored Norris Cotton Cancer Center (NCCC)/Hospice of Vermont and New Hampshire (Hospice VNH) program provided an integrated approach to the management of life-limiting cancer. Project ENABLE was aimed at alleviating the symptoms of disease and treatment, enhancing clinician and patient/family communication, offering support for families, friends and other caregivers, addressing emotional and spiritual needs of dying people and providing conceptual and administrative structure to provide EOL care consistent with patients' values and preferences. Although patient symptom data is not yet available, other measures of success included improved access to hospice and palliative care services from the time of diagnosis and a sustained palliative care program at two of the three sites in which the program was implemented.

Aged↗

PubMed1996

Projection on projective techniques = pathology: the problem that is not being addressed.

A replication of the "levels effect" and reported correlation of "projection" and "pathology" was undertaken using a selected set of Thematic Apperception Test (Murray, 1943) cards varied for ambiguity and scored for pathology and projection. The levels effect was not found for pathology in either a normal or psychiatric group, but was found for projection in the normal group. The correlation between projection and pathology was again clearly confirmed. It was concluded that failure to take into consideration the stimulus properties of the cards and the context in which the test was administered may lead to false attribution of pathology to normal test-takers.

Adolescent↗

PubMed2002

[SNP project in the Millennium Genome Project, Japan].

The basic outlines of the Millennium Genome Project were drawn by the Japanese government on December 19, 1999. In the "Disease gene" team, 5 disease have been chosen as the targets of the Project, Alzheimer's disease, cancer, diabetes, hypertension and asthma. Along with the knowledge-based candidate gene approaches, the complementary strategy of the disease gene hunting, the statistics-based approach, is being deployed. The Project decided to go for a genome-wide, gene-based SNP scan through a close collaboration with another team of the Project, "Standard polymorphism" team, which already discovered c. a. 160,000 SNPs in and around the genes of the Japanese people.

Alzheimer Disease↗

PubMed1994

[[The method for projecting households by family type in terms of headship cohort change--Part 2. Projecting marital status and headship rates by family type in household formation stage]].

"This article is Part 2 of the study on the method for projecting households [in Japan] by family type.... Part 1 was on modelling the transition process among different family types of households headed by [persons] over 35 years old, and on the method for projecting households by family type using the transition model.... Part 2 focuses on the method for projecting households in the formation stage headed by [those] under 34 years old.... Among projection outcomes, the proportion never married of males aged 30-34 goes up from 32.8 per cent to 37.3 per cent between 1990 and 2010, and the proportion never married of females aged 25-29 from 40.4 per cent to 47.1 per cent. [The] tendency of late marriage will continue to the beginning of the twenty-first century." (SUMMARY IN ENG)

Asia↗

PubMed1995

Network-based informatics support of research collaborations in the Human Genome Project and the Human Brain Project.

Sophisticated network-based informatics support will increasingly be required for collaborating biomedical laboratories located in different geographic locations, both to accommodate the massive amount of data being generated in certain fields, and to allow different types of data produced at different laboratories to be analyzed in an integrated fashion. The paper describes the experience of the Yale Center for Medical Informatics in providing informatics support for collaborative projects in gene mapping (as part of the national Human Genome Project) and neuroscience (as part of the national Human Brain Project). The paper describes the informatics needs of the two projects and the solutions being developed, describes certain lessons learned, and discusses certain broader issues that arise.

Brain Mapping↗

PubMed1998

Organization of direct hippocampal efferent projections to the cerebral cortex of the rhesus monkey: projections from CA1, prosubiculum, and subiculum to the temporal lobe.

This study investigates direct hippocampal efferent projections to the temporal lobe of the rhesus monkey. Tritiated amino acid injections were placed into the hippocampal formation to identify terminal fields, and complementary fluorescent retrograde tracer injections were placed into the cortex to identify the cells of origin. Tritiated amino acid injections into CA1, prosubicular, or subicular subfields produced anterograde label over parts of the parahippocampal gyrus and temporal pole. Injections of fluorescent retrograde tracers demonstrated that these projections originate from longitudinal strips of neurons that occupy part of the CA1 subfield as well as from strips of neurons in adjacent prosubicular and subicular subfields. Thus, an injection into area TH of the posterior parahippocampal gyrus labeled neurons in a longitudinal strip of proximal CA1 (i.e., near CA2) as well as a strip in the subiculum; injections into areas TF, TL, 35, or Pro labeled neurons in a longitudinal strip of distal CA1 (i.e., near the prosubiculum) as well as one in the prosubiculum; and an injection into area TFO labeled neurons in a longitudinal strip in the middle of CA1. These strips of neurons extended longitudinally throughout the entire rostrocaudal length of the hippocampus. These results demonstrate that, in the monkey, CA1 projections to cortex arise topographically from longitudinally oriented strips of neurons that occupy only a part of the transverse extent of CA1 but that cover most of the anteroposterior extent of the hippocampus. Thus, in the monkey, CA1 is not a single uniform entity and may have a unique role as a source of direct hippocampal projections to the cerebral cortex.

Animals↗

PubMed2006

Research project: Charleston Bioengineered Kidney Project.

The goal of Charleston Bioengineered Kidney Project is to engineer a functional living human kidney suitable for surgical implantation using principles of directed tissue self-assembly and tissue fusion. This is a multidisciplinary project which incorporates multiple innovative bioengineering technologies and expertise from a broad spectrum of disciplines. The conceptual framework, engineering principles, design, potential cell source as well as the first preliminary data demonstrating the feasibility of the proposed Charleston Bioengineered Kidney Project are outlined. The potential challenges are described. Finally, the experts' opinion about the proposed project is also presented.

Animals↗