70 results match your criteria: "Yale Univ.[Affiliation]"

Model-based deformable surface finding for medical images.

IEEE Trans Med Imaging

October 2012

Dept. of Diagnostic Radiol., Yale Univ., New Haven, CT.

Describes a new global shape parameterization for smoothly deformable three-dimensional (3-D) objects, such as those found in biomedical images, whose diversity and irregularity make them difficult to represent in terms of fixed features or parts. This representation is used for geometric surface matching to 3-D medical image data, such as from magnetic resonance imaging (MRI). The parameterization decomposes the surface into sinusoidal basis functions.

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The authors propose a new approach for tracking the deformation of the left-ventricular (LV) myocardium from two-dimensional (2-D) magnetic resonance (MR) phase contrast velocity fields. The use of phase contrast MR velocity data in cardiac motion problems has been introduced by others (N.J.

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A novel root gravitropism mutant of Arabidopsis thaliana exhibiting altered auxin physiology.

Physiol Plant

March 1998

Dept of Molecular Biophysics and Biochemistry, Yale Univ., New Haven, CT 06520-8114, USA.

A root gravitropism mutant was isolated from the DuPont Arabidopsis thaliana T-DNA insertional mutagenesis collection. This mutant has reduced root gravitropism, hence the name rgr1. Roots of rgr1 are shorter than those of wild-type, and they have reduced lateral root formation.

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The role of natural-killer-cells in the pathogenesis of epstein-barr virus-associated burkitt-lymphoma in a scid mouse model.

Int J Oncol

January 1994

YALE UNIV,SCH MED,DEPT PEDIAT,NEW HAVEN,CT 06510. YALE UNIV,SCH MED,DEPT EPIDEMIOL & PUBL HLTH,NEW HAVEN,CT 06510. YALE UNIV,SCH MED,DEPT PATHOL,NEW HAVEN,CT 06510.

Epstein-Barr virus (EBV) is associated with both benign and malignant lymphoproliferative processes. Recently, mice with severe combined immunodeficiency (SCID) have been described that develop EBV-induced lymphomas when inoculated with peripheral blood lymphocytes from EBV-seropositive individuals. To investigate the pathogenesis of EBV-associated Burkitt lymphomas, we intraperitoneally inoculated SCID mice with cells from EBV-infected Burkitt lymphoma (BL) cell lines.

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Successful therapy to a progressive tumor using monoclonal-antibodies to T-cell regulatory molecules and interleukin-2.

Int J Oncol

September 1993

UNIV N CAROLINA,DEPT PERIODONT,CHAPEL HILL,NC 27514. UNIV N CAROLINA,DEPT MICROBIOL IMMUNOL,CHAPEL HILL,NC 27514. YALE UNIV,SCH MED,DEPT PATHOL,NEW HAVEN,CT 06510. YALE UNIV,SCH MED,HOWARD HUGHES MED INST,NEW HAVEN,CT 06510.

Weekly injections of monoclonal antibodies (mAb) to T-cell regulatory molecules, into animals challenged with a progressively growing epithelial cell tumor 3152-PRO, decreased tumor incidence and caused significantly slower tumor growth, compared with animals given identical treatments of control rat mAb. Some of the mAb showed significant synergy with rIL-2 in the successful therapeutic treatment of 3152-PRO. Furthermore, spleen cells from treated mice generated strong tumor-specific cytotoxic activity.

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Disturbance rejection in nonlinear systems using neural networks.

IEEE Trans Neural Netw

October 2012

Dept. of Electr. Eng., Yale Univ., New Haven, CT.

Neural networks with different architectures have been successfully used for the identification and control of a wide class of nonlinear systems. The problem of rejection of input disturbances, when such networks are used in practical problems is considered. A large class of disturbances, which can be modeled as the outputs of unforced linear or nonlinear dynamic systems, is treated.

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Bayesian reconstruction of functional images using anatomical information as priors.

IEEE Trans Med Imaging

October 2012

Dept. of Diagnostic Radiol., Yale Univ., New Haven, CT.

Proposes a Bayesian method whereby maximum a posteriori (MAP) estimates of functional (PET and SPECT) images may be reconstructed with the aid of prior information derived from registered anatomical MR images of the same slice. The prior information consists of significant anatomical boundaries that are likely to correspond to discontinuities in an otherwise spatially smooth radionuclide distribution. The authors' algorithm, like others proposed recently, seeks smooth solutions with occasional discontinuities; the contribution here is the inclusion of a coupling term that influences the creation of discontinuities in the vicinity of the significant anatomical boundaries.

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An American anesthesia training program in East Africa.

Middle East J Anaesthesiol

October 1992

Dept. of Anesthesiology, Yale Univ. School of Medicine, New Haven, Connecticut.

A unique 5-year program designed to improve the quality and availability of anesthesia care in developing nations has been initiated in East Africa. Based upon North American anesthesiologists serving as volunteer teachers, the program emphasizes teaching to the exclusion of taking over anesthesia care. The teaching is practical and relevant to the clinical practice of anesthesia in developing countries.

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Multiscale optimization in neural nets.

IEEE Trans Neural Netw

October 2012

Dept. of Comput. Sci., Yale Univ., New Haven, CT.

One way to speed up convergence in a large optimization problem is to introduce a smaller, approximate version of the problem at a coarser scale and to alternate between relaxation steps for the fine-scale and coarse-scale problems. Such an optimization method for neural networks governed by quite general objective functions is presented. At the coarse scale, there is a smaller approximating neural net which, like the original net, is nonlinear and has a nonquadratic objective function.

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An extension of the backpropagation method, termed dynamic backpropagation, which can be applied in a straightforward manner for the optimization of the weights (parameters) of multilayer neural networks is discussed. The method is based on the fact that gradient methods used in linear dynamical systems can be combined with backpropagation methods for neural networks to obtain the gradient of a performance index of nonlinear dynamical systems. The method can be applied to any complex system which can be expressed as the interconnection of linear dynamical systems and multilayer neural networks.

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Associative learning in random environments using neural networks.

IEEE Trans Neural Netw

October 2012

Dept. of Electr. Eng., Yale Univ., New Haven, CT.

Associative learning is investigated using neural networks and concepts based on learning automata. The behavior of a single decision-maker containing a neural network is studied in a random environment using reinforcement learning. The objective is to determine the optimal action corresponding to a particular state.

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An approach to analyzing and quantifying the shape characteristics of the endocardial contour of the left ventricle of the heart is described. The computation begins by finding the local curvature differences between the contour under consideration and the mean normal contour at each of 100 equidistant points. The weighted square of these differences, summed over a set of points, is shown to be the regional or, global bending energy required to deform the mean normal contour to the characteristic shape of the analyzed contour.

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Identification and control of dynamical systems using neural networks.

IEEE Trans Neural Netw

October 2012

Dept. of Electr. Eng., Yale Univ., New Haven, CT.

It is demonstrated that neural networks can be used effectively for the identification and control of nonlinear dynamical systems. The emphasis is on models for both identification and control. Static and dynamic backpropagation methods for the adjustment of parameters are discussed.

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An improved theory for the prediction of microcavitation thresholds.

IEEE Trans Ultrason Ferroelectr Freq Control

October 2012

Yale Univ., New Haven, CT.

An approximate analytical formulation is presented that allows for the calculation of acoustic pressure thresholds for transient cavitation over a variety of frequencies and host fluid parameters. Specifically, R.E.

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Although prostaglandins (PGs) are considered the key mediators of human parturition at term, there is a paucity of data regarding their participation in the mechanisms responsible for preterm labor. The purpose of this study was to establish if preterm labor is associated with changes in the amniotic fluid concentrations of prostaglandins. PGF2 alpha, 13,14-dihydro-15-keto-prostaglandin F2 alpha (PGFM) and 11-deoxy-13,14-dihydro-15-keto-11,16-cyclo-prostaglandin E2 (PGEM-ll) were measured by using specific and sensitive radioimmunoassays.

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We have produced a contrasuppressor T cell hybridoma which has positive effects on multiple forms of cell-mediated immunity. First of all, it protects the adoptive transfer of contact sensitivity from suppressor cells and factors. In addition, TcsF modifies the response to normally tolerogenic administrations of hapten, leading mice to develop contact sensitivity and CTL activity instead of tolerance.

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Two populations of primary osteoblasts and the cloned murine osteoblast cell line MC3T3 were activated with osteotropic agents and the conditioned media tested for the presence of macrophage colony stimulating factor (M-CSF). Differences in ability of the three populations to secrete the cytokine as well as in the efficacy of the activating agents used to induce it were observed. The ability of these agents to modulate M-CSF mRNA levels was also examined.

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Supercomputing in medical imaging.

IEEE Eng Med Biol Mag

July 2011

Dept. of Diagnostic Imaging, Yale Univ. Med. Sch., New Haven, CT.

It is suggested that the diagnostic imaging department of the future will make extensive use of computer networks, mass storage devices, and sophisticated workstations at which humans and machines will interact, assisted by techniques of computer vision and artificial intelligence, to achieve integration of multimodality imaging information and expert medical knowledge. Recent developments in medical imaging are described, and manipulation, display, and analysis techniques that are likely to benefit from supercomputing are examined. The following image processing tasks are discussed; restoration of images; spatial and temporal image and image sequence analysis; image restoration; mathematical image reconstruction from projections; and three-dimensional image analysis.

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