Showing papers by "University of Washington published in 1975"

The central adrenergic system. An immunofluorescence study of the location of cell bodies and their efferent connections in the rat utilizing dopamine‐B‐hydroxylase as a marker

Abstract: A sensitive immunofluorescence technique was used to describe systematically the distrubution of dopamine-beta-hydroxylase (DBH)-containing cell bodies, non-terminal fiber pathways, and terminal fields in the brain of the male albino rat. DBH is the enzyme that catalyzes the conversion of dopamine to noradrenaline, and as such is useful as an anatomical marker for noradrenaline and possibly adrenaline neurons. The enzyme is not present in dopamine- or indolamine-containing neurons. Ten micron frozen sections (1-in 20 series) were prepared in the frontal, sagittal, and horizontal planes from the olfactory bulb to the upper cervical segments of the spinal cord; adjacent sections in each plane were stained for DBH and for cells (toluidine blue=azure II). An atlas consisting of 40 projection drawings of selected frontal sections illustrates the results of the investigation. DBH perikarya are confined to three groups in the pons and medulla: the well defined locus coeruleus, a more diffuse but continuous subcoeruleus group that arches through the pons and ventral medulla, and a third dorsal medullary group centered in the dorsal motor nucleus of the vagus. A single principal adrenergic fiber system distributes a great many of the axons from these neuron groups to a majority of nuclear areas in the brain. In the pons and medulla two components of the fiber system may be distinguished. A medullary branch may be followed from the posterior aspect of the subcoeruleus group dorsally and then anteriorly through the lateral tegmental field and ventral aspect of the vestibular complex to a position subjacent to the locus coeruleus, where it is joined by a subcoeruleus branch consisting of a large number of fibers coursing among cells along the length of the subcoeruleus group, and by fibers arising from the locus coeruleus. Anterior to the locus coeruleus the principal adrenergic bundle courses as a single fiber tract immediately ventrolateral to the central gray in the mesencephalon and in the zona incerta and substantia innominata in the diencephalon. At the level of the septal area separate bundles reach the cortex dorsally over the genu of the corpus calosum via the medial septal-diagonal band nuclei and the lateral septum and ventrally between the olfactory tubercle and caudate-putamen. In the medulla and pons adrenergic fibers undoubtedly course in both directions. Anterior to the most rostral pontine cell bodies, however, all fibers presumably ascend. Along the course of the bundle distinct branches emerge to innervate circumscribed terminal fields. In addition, certain regions of the brain such as the reticular formation and pontine gray receive diffuse DBH innervation derived from less clearly defined pathways. A small number of areas in the brain contain little or no detectable DBH. These include the caudate-putamen, nucleus accumbens, globus pallidus, olfactory tubercle, subthalamic nucleus, substantia nigra, pretectal area, third, fourth and sixth cranial verve nuclei, and the trapezoid body nucleus.

Explicit Calculation of the Rarefaction Diversity Measurement and the Determination of Sufficient Sample Size

Abstract: An explicit means of calculating the expected number of species [E(Sn)] and the variance of (Sn) in a random sample of n individuals from a collection containing N individuals and S species is presented. An example illustrates a new use of E(Sn): determination of the sample size required for any desired degree of accuracy in collecting species known to occur in a particular area.

Association of exogenous estrogen and endometrial carcinoma.

Abstract: To determine the association between the incidence of endometrial cancer and the use of estrogen in menopausal and post-menopausal women, we retrospectively compared 317 patients with adenocarcinoma of the endometrium with an equal number of matched controls having other gynecologic neoplasms; 152 patients used estrogen, as compared to 54 of 317 controls. Thus, the risk of endometrial cancer was 4.5 times greater among women exposed to estrogen therapy. When estrogen use was adjusted for concomitant variables such as obesity, hypertension, diabetes, parity, referral pattern, age at diagnosis, year of diagnosis and other gynecologic neoplasms, the magnitude of the increased relative risk was associated with several of these variables, and was highest in patients without obesity and hypertension. Exogenous estrogen therapy is associated with an increased risk of endometrial carcinoma, but this increased relative risk is less apparent in patients with physiologic characteristics previously associated with an increased risk.

Theory of the extended x-ray absorption fine structure

Abstract: The extended x-ray absorption fine structure is a consequence of the modification of the photoelectron final state due to scattering by the surrounding atoms. We present a theory of the absorption fine structure starting from theoretically obtained electron-atom scattering phase shifts. The electron scattering is treated using a spherical wave expansion which takes into account the finite size of the atoms. Multiple-scattering effects are included by classifying multiple-scattering paths by their total path lengths. Their effects are quite large but appear to make quantitative but not qualitative changes on the single-scattering contribution. The exceptional case is the fourth shell in fcc or bcc structure, where it is shadowed by the first-shell atom and is profoundly affected by forward scattering due to the first shell. This may account for the anomaly observed experimentally at the fourth-shell radius in metals. A detailed numerical calculation is carried out for copper and is shown to agree quite well with experiment.

On the Structure of Polynomial Time Reducibility

Abstract: Two notions of polynomml time reduclbihty, denoted here by ~ T e and <.~P, were defined by Cook and Karp, respectively The abstract propertms of these two relatmns on the domain of computable sets are investigated. Both relations prove to be dense and to have minimal pairs. Further , there is a strictly ascending sequence with a minimal pair of upper bounds to the sequence. Our method of showing density ymlds the result that if P ~ NP then there are members of NP -P that are not polynomml complete

The origin of efferent pathways from the primary visual cortex, area 17, of the macaque monkey as shown by retrograde transport of horseradish peroxidase

Abstract: The retrograde transport of horseradish peroxidase has been used to identify efferent cells in area 17 of the macaque. Cells projecting to the lateral geniculate nucleus are small to medium sized pyramidal neurons with somata in lamina 6 and the adjacent white matter. The projection to the parvocellular division arises preferentially from the upper half of lamina 6, while that to the magnocellular division arises preferentially from the lower part of the lamina. The projection to both superior colliculus and inferior pulvinar arises from all sizes of pyramidal neurons lying in lamina 58 (Lund and Boothe, '75); at least pyramidal neurons of lamina 5B send collateral axon branches to both destinations. Injections with extensive spread of horseradish peroxidase show that many cells of lamina 4B and the large pyramidal neurons of upper lamina 6 also project extrinsically but their terminal sites have not been identified. Other studies have indicated that cells of laminae 2 and 3 project to areas 18 and 19. Therefore every lamina of the visual cortex, with the exception of those receiving a direct thalamic input, contains cells projecting extrinsically. Further, each lamina projects to a different destination and from Golgi studies can be shown to contain cells with specific patterns of dendritic branching which relate to the distribution of thalamic afferents and to the patterns of intracortical connections. These findings emphasise the significance of the horizontal organisation of the cortex with relation to the flow of information through it and contrast with the current concept of columnar organisation shown in physiological studies.

Extended x-ray-absorption fine-structure technique. III. Determination of physical parameters

Abstract: Fourier transforms of extended x-ray-absorption fine structure (EXAFS) give structural information in the vicinity of each kind of atom, separately, in a wide variety of gaseous, liquid, and solid systems. A detailed description of the analysis of EXAFS data is presented including details of the Fourier transform of the data and the extraction of structural and other physical parameters from these transforms. Included in this description are the measurement of interatomic distances, coordination numbers, disorder effects (thermal and structural), energy-dependent electron scattering amplitudes, inelastic mean free paths, and phase shifts. EXAFS spectra of Ge, Cu, and Ge${\mathrm{O}}_{2}$ are analyzed in detail. Multiple-scattering effects between atoms are generally found to be small. There are no multiple-scattering effects in the first shell of the Fourier transform. The phase shifts introduced by both the absorbing and surrounding atoms empirically appear to be characteristic of the particular atoms and independent of the surroundings for a given class of material. This is of great practical importance because it indicates that EXAFS can be calibrated by measuring known structures and then used to determine unknown ones.

Negative surface charge near sodium channels of nerve: divalent ions, monovalent ions, and pH.

Abstract: Evidence is given for a high density of negative surface charge near the sodium channel of myelinated nerve fibres The voltage dependence of peak sodium permeability is measured in a voltage clamp The object is to measure voltage shifts in sodium activation as the following external variables are varied: divalent cation concentration and type, monovalent concentration, and pH With equimolar substitution of divalent ions the order of effectiveness for giving a positive shift is: Ba equals Sr less than Mg less than Ca less than Co approximately equal to Mn less than Ni less than Zn A tenfold increase of concentration of any of these ions gives a shift of +20 to +25 mV At low pH, the shift with a tenfold increase in Ca-2+ is much less than at normal pH, and conversely for high pH Soulutions with no added divalent ions give a shift of minus 18 mV relative to 2 mM Ca-2+ Removal of 7/8 of the cations from the calcium-free solution gives a further shift of minue 35 mV All shifts are explained quantitatively by assuming that changes in an external surface potential set up by fixed charges near the sodium channel produce the shifts The model involves a diffuse double layer of counterions at the nerve surface and some binding of H+ions and divalent ions to the fixed charges Three types of surface groups are postulated: (1) an acid pKa equals 288 charge density minus 09 nm- minus 2; (i) an acid pKa equals 458, charge density minus 058 nm- minus 2; (3) a base pKa equals 628, charge density +033 nm- minus 2 The two acid groups also bind Ca-2+ ions with a dissociation constant K equals 28 M Reasonable agreement can also be obtained with a lower net surface charge density and stronger binding of divalent ions and H+ ions

Diurnal Variations in Precipitation and Thunderstorm Frequency over the Conterminous United States

Abstract: Hourly data on the frequencies of all types of precipitation events, heavy precipitation events, trace precipitation events and thunderstorms for more than 100 stations in the United States were processed to generate statistics on the amplitude and phase of the diurnal and semidiurnal cycles at each station. Results are displayed on seasonal maps in a vectorial format that emphasizes the large scale geographical consistency of the diurnal variations. During summer each of the four parameters listed above displays a distinctive geographical pattern of diurnal variations. Thunderstorm frequency tends to be the most strongly modulated by the diurnal cycle; trace precipitation the least strongly modulated. Over the central United States the maximum frequency of severe convective storms occurs during the early evening; thunderstorms exhibit their maximum frequency around midnight, while most precipitation falls later in the night. These amplitude and phase differences offer some insight into the relat...

Extended x-ray-absorption fine-structure technique. II. Experimental practice and selected results

Abstract: A technique is presented for obtaining extended x-ray-absorption fine structure (EXAFS) using a conventional, horizontal, x-ray diffractometer. Preparation of monochromator crystals, spectrometer alignment, counting techniques, evaluation of the energy scale and data normalization techniques are discussed. EXAFS spectra from a wide variety of materials are then presented to show the variability of the effect and interplay between various parameters of the theory. A final section illustrates a simple graphical scheme to obtain a first-neighbor distance from EXAFS data.

The social significance of avian winter plumage variability.

Abstract: Animal species vary enormously in the degree to which individuals are similar or different from one another in appearance. In some birds, such as juncos and Harris sparrows, most individuals look different from each other, while in others, such as chickadees and song sparrows, there is little individual variation. These differences in appearance among species require several levels of interpretation. First, an understanding of their social significance is required for us to know what is being communicated by these differences. Second, we should understand the proximate mechanisms by which a correspondence between signal and message is achieved. Finally, we must understand the ecological factors which are ultimately responsible for the social systems and their associated plumage patterns. This paper is addressed only at the social significance of winter plumage variability versus monomorphism. Ordering principles pertaining to animal coloration-theories relating appearance to camouflage, advertisement, physiology, or the formation of search images-are of little help in explaining why some winter birds are highly variable and others monomorphic. The first three of these theories invoke selective principles which are expected to produce monomorphic patterns within populations and, thus, do not relate to plumage variability. Camouflage coloration is expected to select for monomorphism achieved through mimicry of environmental background, substrate color or specific objects. Likewise, advertisement or poster coloration (Lorenz, 1967), evolved by selection for warning coloration, mimicry, species or sex recognition, or advertisement of territorial possession, is not expected to lead to intra-population variability. In some cases of mimicry this is not true, but these cases always select for discontinuous variation, with morphs mimicking various discrete models. Finally, selection upon color pattern for physiological efficiency depends upon assuming one of the radiation colors, generally either black or white (Hamilton, 1973). Small temperate land birds are rarely uniformly white or black, suggesting that physiological needs have probably not been primal in determining their color patterns. Formation of search images does anticipate variability in populations and is sometimes raised to explain the highly variable plumages of certain birds. Clarke (see 1969, and references cited therein) originated the idea to explain the Cepaea snail polymorphisms through apostatic predation, and Croze (1970) has done much

The Fetal Alcohol Syndrome

Abstract: A specific pattern of malformation involving prenatal-onset growth deficiency, developmental delay, craniofacial anomalies, and limb defects is now recognized in offspring of chronic alcoholic women. Historical evidence suggests that this is not a new observation. A recent French study of 127 offspring of alcoholic mothers indicates that this specific syndrome has been recognized in other parts of the world. Many of the features of this disorder could be related to the kind of malorientation of brain structure seen at the autopsy of one patient described herein. The frequency (43%) of adverse outcome of pregnancy for chronic alcoholic women suggests that serious consideration be given to early termination of pregnancy in severely chronic alcoholic women.

Etiology of Nongonococcal Urethritis

Abstract: Chlamydia trachomatis was isolated from the urethra from 48 (42 per cent) of 113 men with non-gonococcal urethritis (NGU), four (7 per cent) of 58 without overt urethritis, and 13 (19 per cent) of 69 with gonorrhea. Postgonococcal urethritis (PGU) developed in 11 of 11 men who had C. trum antibody to C. trachomatisis developed. The immunotype specificity of chlamydial antibody corresponded to the immunotype isolated. Among culture-negative patients. chlamydial antibody prevalence correlated with the number of past sex partners and with previous NGU. Herpesvirus hominis, cytomegalovirus, T-mycoplasma, Mycoplasma hominis, other bacteria, and Trichomonas vaginalis were not implicated in NGU or PGU. Thus, the cause of chlamydia-negative NGU and PGU remains obscure. Endocervical chlamydia were found in sex partners of 15 of 22 NGU patients with and two of 24 without urethral chlamydial infection (p smaller than 0.001). Tetracycline treatment of both sex partners appears advisable.

Approximate non-Gaussian filtering with linear state and observation relations

Abstract: Two approaches to the non-Gaussian filtering problem are presented. The proposed filters retain the computationally attractive recursive structure of the Kalman filter and they approximate well the exact minimum variance filter in cases where either 1) the state noise is Gaussian or its variance small in comparison to the observation noise variance, or 2) the observation noise is Gaussian and the system is one step observable. In both cases, the state estimate is formed as a linear prediction corrected by a nonlinear function of past and present observations. Some simulation results are presented.

Development of gender constancy and selective attention to same-sex models.

Abstract: 4 developmental levels of gender constancy were identified in 55 preschool-age children on the basis of a reproducible Guttman scale of answers to sets of questions pertaining to gender identity, gender stability over time, and gender consistency across situations. Children's developmental level of gender constancy was predictive of the amount and the proportion of time they attended to an adult male and an adult female film model. As boys developed gender constancy, their relative preference for watching the male model increased significantly; as girls developed gender constancy, their relative preference for watching the female model increased, though not significantly. At the more advanced levels of gender constancy, boys watched the male model more than did girls. It was suggested that same-sex social learning may develop as a function of children's cognitive understanding of gender as an identifiable, stable and consistent human attribute.

New knowledge of chlamydiae and the diseases they cause.

Abstract: The trachoma and LGV organisms, the human pathogens of the species C. trachomatis, cause oculogenital infections and disease syndromes of the eye and genital tract. The incidence of the most prominent disease, endemic trachoma with eye-to-eye transmission, is decreasing all over the world. At the same time there is increasing recognition of high-frequency venereal infections with trachoma organisms and of the genital disease and occasional ocular disease that they cause. Laboratory techniques for diagnosis and investigation are improving, but work with these interesting intermediate agents remains more difficult than that with many other microorganisms. Proper recognition of the diseases is important because specific therapy is available.

Ionic selectivity, saturation, and block in sodium channels. A four-barrier model.

Abstract: Ionic fluxes in Na channels of myelinated axons show ionic competition, block, and deviations from simple flux independence. These phenomena are particularly evident when external Na+ ions are replaced by other permeant or impermeant ions. The observed currents require new flux equations not based on the concepts of free diffusion. A specific permeability model for the Na channel is developed from Eyring rate theory applied to a chain of saturable binding sites. There are four energy barriers in the pore and only one ion is allowed inside at a time. Deviations from independence arise from saturation. The model shows that ionic permeability ratios measured from zero-current potentials can differ from those measured from relative current amplitudes or conductances. The model can be fitted to experiments with various external sodium substitutes by varying only two parameters: For each ion the height of the major energy barrier (the selectivity filter) determines the biionic zero-current potential and the depth of the energy well (binding site) just external to that barrier then determines the current amplitudes. Voltage clamp measurements with myelinated nerve fibers are given showing numerous examples of deviations from independence in ionic fluxes. Strong blocks of ionic currents by guanidinium compounds and Tl+ ions are fitted by binding within the channel with apparent dissociation constants in the range 50-122 mM. A small block with high Na+ concentrations can be fitted by Na+ ion binding with a dissociation constant of 368 mM. The barrier model is given a molecular interpretation that includes stepwise dehydration of the permeating ion as it interacts with an ionized carboxylic acid.

Quantum Field Theory in Schwarzschild and Rindler Spaces

Abstract: The problem of defining a scalar quantum field in the space-times described by the Schwarzschild and Rindler metrics is discussed. The matrix elements of the field operators are found by calculating the Green's functions for the fields. The requirement of positive frequencies for asymptotic timelike separations combined with a careful analysis of the continuity conditions at the event horizons yields a unique prescription for the Green's function. This is turn defines the vacuum state. In the Schwarzschild space the vacuum is shown to be stable and the lowest-energy state. In the Rindler space the quantization procedure yields the same results as quantization in Minkowski coordinates.