Showing papers by "University of British Columbia published in 1977"

Attachment as an Organizational Construct

Abstract: Developmentalists have often conceptualized infant-adult ties in terms of an implicit trait construct evolved from the study of dependency. The major dimension of individual differences has been conceptualized in terms of quantitative differences in the "strength" of attachments, and a variety of discrete behaviors (touch, look, smile, approach, cling, cry) have been assumed to be valid "indices" of this dimension. These behaviors have been assumed to be significantly intercorrelated and stable across situations and over time. Critics have argued strongly that these assumptions cannot be defended empirically. It has further been argued that the study of individual differences in infant-adult ties is unlikely to he a productive research strategy and that attachment (as implying anything more than infant-adult interaction) has outlived its usefulness as a developmental construct. When, however, trait models are abandoned and greater attention is paid to the functions, outcomes, and context sensitivity of attachment behavior and to the underlying behavioral control systems that organize it, the apparent conflict between situational influences and stable individual differences can be resolved. The study of changes in the organization of behavior during development provides a framework for productive individual differences research. When greater emphasis is placed on the organization of behavior, both the stability and the flexibility of attachment behavior can be comprehended, and the attachment construct can continue to play an important integrative role in developmental theory.

On the role of ascending catecholaminergic systems in intravenous self-administration of cocaine.

Abstract: The role of ascending noradrenergic (NA) and dopaminergic (DA) systems in intravenous self-administration of cocaine in rats was investigated by examining the effects of 6-hydroxydopamine-induced lesions of these systems on responding for the drug on a FR-1 schedule of reinforcement. Lesions of the dorsal and ventral NA bundles that reduced hippocampal-cortical NA by 96% and hypothalamic NA by 72% failed to have any effects on responding for cocaine. Lesions of the nucleus accumbens that reduced the DA content of this nucleus by 90% resulted in a significant and long-lasting (15 days) reduction in self-administration of cocaine. Apomorphine self-administration was not affected in the same animals. Identical lesions of the n accumbens had only transient (2-3 days) effects on food-reinforced operant responding, suggesting that the prolonged disruption of cocaine self-administration was not the result of motor deficits. The results are discussed with reference to the possibility that DA terminals in the n accumbens may mediate some of the positive reinforcing properties of cocaine.

An Epitaph for the Concept of Maximum Sustained Yield

Abstract: (1977). An Epitaph for the Concept of Maximum Sustained Yield. Transactions of the American Fisheries Society: Vol. 106, No. 1, pp. 1-11.

Atlanto-axial rotatory fixation. (Fixed rotatory subluxation of the atlanto-axial joint)

Abstract: In seventeen cases of irreducible atlanto-axial rotatory subluxation (here called fixation), the striking features were the delay in diagnosis and the persistent clinical and roentgenographic deformities All patients had torticollis and restricted, often painful neck motion, and seven young patients with long-standing deformity had flattening on one side of the face The diagnosis was suggested by the plain roentgenograms and tomograms and confirmed by persistence of the deformity as demonstrated by cineroentgenography Treatment included skull traction, followed by atlanto-axial arthrodesis if necessary Of the thirteen patients treated by atlanto-axial arthrodesis, eleven had good results, one had a fair result, and one had not been followed for long enough to determine the result Of the remaining four patients, one treated conservatively had not been followed for long enough to evaluate the result, two declined surgery, and one died while in traction as the result of cord transection produced by further rotation of the atlas on the axis despite the traction

Production and origin of oral malodor: a review of mechanisms and methods of analysis.

Abstract: Organoleptic studies indicate that the oral cavity is usually the principal source of physiologic malodor associated with the early morning halitosis. In all individuals, regardless of the age or health status of the oral tissues, the most intense oral malodor is exhibited after prolonged periods of reduced saliva flow and abstinence from food and liquid. This results from normal metabolic activity in the oral cavity and is accentuated in cases with periodontal involvement. Physiologic oral malodor is transient in duration as it can be controlled to varying degrees in most individuals by oral hygiene measures, such as tooth brushing, dental prophylaxis, tongue scraping and rinsing with antiseptic mouth washes. Experimental evidence strongly suggests that putrefaction of sulphur-containing proteinaceous substrates by predominantly gram-negative oral microorganisms is the primary cause of oral malodor. Optimum putrefactive activity occurs in low carbohydrate environment, physiological pH, and anaerobic conditions. Salivary sediment containing the exfoliated epithelial cells is the primary source of substrate which exists in a disulphide state. Proteolysis and reduction of disulphide bonds precedes the formation of odor. The odor intensity of putrescent saliva and plaque head-space vapor has been correlated with the concentration of volatile sulphur compounds consisting of hydrogen sulphide, methyl mercaptan, dimethyl sulphide and dimethyl disulphide. Except for dimethyl disulphide, the same sulphur-containing compounds have been found in mouth air of all tested individuals. Hydrogen sulphide and methyl mercaptan emanate an offensive putrid odor and account for approxiamtely 90% of the total sulphur content of mouth air. In half of the population tested, methyl mercaptan and hydrogen sulphide content of early morning mouth air is sufficiently high to account for the oral malodor. Brushing studies indicate that both plaque and tongue are important sources of malodor with most of the odor emanating from the dorso-posterior surface of the tongue. None of the gas chromatographic or mass spectrometric analyses have detected the presence of amines, indole, or skatole in the head-space, mouth air, or breath vapor samples.

Biomechanical analysis of static forces in the thumb during hand function.

Abstract: Using a three-dimensional analysis, the internal forces in the joints and soft tissues of the thumb during pinch and grasp were calculated. To do this, mechanical equivalents were ascribed to the anatomical system, the joint orientation and tendon locations were determined from biplanar roentgenograms of five marked normal cadaver specimens, and the magnitudes of forces in the tendons, intrinsic muscles, joint contact surfaces, and constraining ligaments were calculated based on assumed loads applied to the tip of the thumb in various types of pinch and grasp. These results are the direct extension of a two-dimensional analysis that proved inadequate for the determination of static tendon and joint forces. Extrinsic and intrinsic tendons of the thumb were found to sustain forces of up to 10.0 and thirty kilograms during pinch, producing five kilograms of force at the thumb tip and forces of as much as fifty kilograms during grasp. The joint compression (contact) forces averaged three kilograms of force at the interphalangeal joint, 5.4 kilograms at the metacarpophalangeal joint, and 12.0 kilograms at the carpometacarpal joint during simple pinch (one kilogram of applied force). Compression forces of as much as 120 kilograms may occur at the carpometacarpal joint during strong grasp.

The oxygen transport system in trout (salmo gairdneri) during sustained exercise

Abstract: 1. The capabilities of the oxygen transport system of rainbow trout in supplying the increased oxygen demands in exercise, in a water tunnel at 9–10.5 °C, have been investigated by increasing the velocity of water flow, with a 1 h period between increments, up to the maximum swimming speed (critical velocity, U crit ). 2. At U crit , N O2 was elevated above the resting level by 7.5 times. The logarithm of N O O2 was linearly related to the swimming speed expressed as a proportion of U crit . V g increased in almost direct proportion to the increase in N O O2 . 3. Heart rate rose slightly at half U crit and reached a maximum, 1.6 times the resting rate, as U crit was approached. Ventral and dorsal aortic mean blood pressures rose by 60% and 20% respectively at U crit while their pulse pressures doubled. Central venous pressure was virtually unchanged. 4. P a, O a, O2 fell slightly during exercise but C a, O a, O2 was unaffected. On the other hand P v, O v, O2 halved and C v, O v, O2 fell from 3.17 (S.E. = 0.3) to 0.6(S.E. = 0.7) mmol/1. Cardiac output increased by about 3 times resting values. 5. The results are discussed and an attempt is made to estimate the maximum capabilities of the components of the oxygen transport system in sustained exercise.

The Energy Balance of an Urban Canyon

Abstract: This study investigates the energy exchanges occurring within an urban canyon. It considers not only the energy balances of each of the canyon component surfaces (walls and floor), but also the balance of the canyon system and of the air volume contained therein. The results are based on measurements conducted in a specially instrumented canyon during a period of fine anticyclonic summer weather in Vancouver, B.C. The timing and magnitude of the energy regime of the individual canyon surfaces are shown to be very different from each other, each being strongly affected by the influence of the canyon geometry on the radiation exchanges. The diurnal course of the canyon system energy balance is relatively smooth and symmetric. By day the canyon system radiative surplus is mainly dissipated by turbulent transfer, and the remaining 25–30% is stored in the canyon materials. In contrast, the nocturnal radiative deficit is almost entirely balanced by the release of subsurface heat storage. Advective cont...

The fetal alcohol syndrome in mice: An animal model†‡

Abstract: CBA and C3H female mice were maintained on liquid diets--Metrecal plus ethanol--containing 15-35% ethanol-derived calories. These diets, which resulted in alcohol blood levels of 73-398 mg/100 ml blood in nonpregnant females, were the sole sustenance for the females for at least 30 days before and throughout gestation. Females were killed on day 18 of gestation and offspring examined for skeletal and soft tissue anomalies. Prenatal death and maldevelopment increased with the level of alcohol intake. Deficient occiput ossification, neural anomalies, and low fetal weight occurred with low ethanol diets, and cardiac and eye-lid dysmorphology with higher ethanol diets. This pattern of malformations, which exhibited both a dose-response effect and strain differences in susceptibility, indicated that chronic maternal alcoholism is embryolethal and teratogenic in mice.

Integrative Complexity of Communications in International Crises

Abstract: Diplomatic communications during international crises that resulted in war (1914 and 1950) and crises that were settled peacefully (1911, 1948, 1962) were scored for integrative complexity. This is...

Fifty centuries of right-handedness: the historical record.

Abstract: A survey of more than 5000 years of art work, encompassing 1180 scorable instances of unimanual tool or weapon usage, revealed no systematic trends in hand usage. The right hand was used in an average of 93 percent of the cases, regardless of which historical era or geographic region was assessed.

Rb-Sr and K-Ar geochronometry of Mesozoic granitic rocks and their Sr isotopic composition, Oregon, Washington, and Idaho

Abstract: Mesozoic orogeny and magmatism began in the northwestern United States soon after deposition of Permian strata, but no rocks have yet been dated from the Permian-Triassic orogenic period. Middle Triassic to Late Jurassic sediment sequences include major unconformities and evidence of several episodes of igneous activity. An early culmination of magmatism occurred in Late Triassic and Early Jurassic time (200–217 m.y. ago) in eugeosynclinal parts of far western Idaho. A widespread and intense culmination in Late Jurassic time was the final major orogenic event in the Oregon eugeosyncline. The Bald Mountain (147 to 158 m.y. old), Wallowa (probably 143 to 160 m.y. old but affected by Cretaceous metamorphism), Deep Creek (at least 137 m.y. old), and many other plutons in the Blue and Klamath Mountain regions in Oregon and in western Idaho were emplaced shortly before the end of Jurassic. The bulk of the Idaho batholith was emplaced during a Cretaceous culmination of igneous activity — the southern (Atlanta) lobe about 75 to 100 m.y. ago and the northern (Bitterroot) lobe about 70 to 80 m.y. ago. Much of the batholith was affected by Eocene magmatism which resulted in widespread resetting of isotopic dates for older rocks to values of 50 m.y. or less. Between 55 and 70 m.y. ago, there was a lull in igneous activity in the northwestern United States. Sr isotope initial ratios change abruptly across a boundary in western Idaho from ∼0.7040 or less, to the west, to ∼0.7060 or greater, to the east. This change marks the boundary between Precambrian crust and Phanerozoic eugeosyncline. The geologic setting of the observed transition and its time independence suggest that it is due to contamination and assimilation processes involving magmas from the mantle and enclosing crustal rocks. Contamination of magmas with radiogenic Sr renders the Sr whole-rock isochron technique useless in dating the Idaho batholith and other intrusive rocks in central and eastern Idaho, areas underlain by Precambrian basement.

Dispersion energy constants C 6(A, B), dipole oscillator strength sums and refractivities for Li, N, O, H2, N2, O2, NH3, H2O, NO and N2O

Abstract: Accurate values for the orientation-averaged long-range dipole-dipole dispersion energy coefficients, C 6(A, B), have been determined for all possible pair interactions involving ground state H, Li, N, O, H2, N2, O2, NH3, H2O, NO, and N2O. The calculations have been carried out by employing dipole oscillator strength distributions for these species that have been constructed (except in the case of H) by using discrete oscillator strength, photo-absorption, and high energy inelastic scattering data and by requiring the distributions to reproduce the Thomas-Reiche-Kuhn sum rule and, in the case of the molecules, available accurate refractivity and dispersion measurements for the relevant dilute gases. These oscillator strength distributions were also used to evaluate the refractivity R(λ), as a function of wavelength λ in the visible and ultra-violet region below the ultra-violet absorption thresholds, and the dipole oscillator strength sums S -2l , l = 1, 2, …, 7, for each atom and molecule. The calculated...

Crack formation in the continuous casting of steel

Abstract: This review examines the different types of internal and surface cracks that can form during the continuous casting of steel. For each crack type, the operating and metallurgical factors that are known to influence crack formation are assessed in the light of the high temperature mechanical properties of steel and a knowledge of the stresses generated in the solidifying shell. The importance of two zones of low ductility in steel is demonstrated by this approach. One zone exists above 1340°C and probably accounts for the formation of all internal cracks and surface longitudinal cracks. The other zone lies between 700 and 900°C and is related to the presence of soluble aluminum, niobium and vanadium. Transverse surface cracks in slabs can be related to the latter zone.

Microbial respiration and substrate weight loss—I

Abstract: A general model of the influences of abiotic variables on microbial respiration and substrate weight loss is presented The model, a complex hypothesis relating microbial respiration to temperature moisture, O2 and substrate, “explains” 71–96% of the variation in aerobic respiration rates measured from a variety of natural substrates The model can project seasonal patterns of weight loss and thus permits evaluation of laboratory respirometry against field measures using litter bags Using data from several countries simulated losses due to microbial respiration are 70–90% of the measured litter bag loss

Application of magnetic microspheres in labelling and separation of cells

Abstract: POLYMERIC microspheres conjugated to antibodies and lectins have been used previously as cell surface markers for the detection and localisation of antigens and lectin receptors using scanning electron microscopy (SEM) (refs 1–4). In this report we describe a new, more versatile cell surface probe consisting of iron-containing polymeric microspheres tagged with fluorescent dyes and chemically coupled to antibodies or lectins. The magnetic and fluorescent properties of these microspheres have been utilised in the magnetic separation of red blood cells (RBC) and lymphoid cells and in the detection of immunoglobulin (Ig) receptors and wheat germ agglutinin (WGA) receptors on lymphocytes and Hela cells by SEM and fluorescent microscopy.

An Effective Stress Model for Liquefaction

Abstract: The important factors affecting the dynamic response of saturated sand layers to earthquake motions are: (1)The initial shear modulus in situ; (2)the variation of shear modulus with shear strain; (3)contemporaneous generation and dissipation of pore-water pressures; (4)changes in effective mean normal stress; (5)damping; and (6)hardening. Constitutive relations are formulated that take all these factors into account and these are incorporated into a nonlinear method for the dynamic effective stress analysis of saturated sands. The method predicts the phenomenological features of the dynamic response of saturated sand layers that commonly occur as the pore-water pressure rises in the sand during earthquake shaking. It allows the distribution of pore-water pressure and the effects that drainage and internal flow have on the location and time of liquefaction to be determined quantitatively.

A comparison of empirically derived groups of aphasic patients on the Neurosensory Center Comprehensive Examination for Aphasia

Abstract: Rating scales were used to identify characteristic aphasic phenomena in a sample of natural language from aphasic patients. These variables were used to derive empirically four groups of aphasic patients. These groups showed significant multivariate differences on the basis of their performance on the Neurosensory Center Comprehensive Examination for Aphasia. Seven subtests showed significant univariate differences among the four groups: Visual Naming, Description of Use, Sentence Repetition, Repetition of Digits, Reversal of Digits, Identification by Sentence, and Oral Reading Sentences. Two of the groups reflected Howes dichotomy of articulate-nonarticulate language disorders. Another group was thought to reflect Schuell's single dimension of language disorders that could be differentiated only in terms of severity. Afourth group was characterized by a major impairment of memory. These results indicated that aphasic phenomena could be identified reliably on the basis of rating of verbal output on scales that reflect language disorders. These scales were used in a statistical fashion to derive empirically oriented groups that were identified on the basis of psychometric measures of language skills.

Respiratory and Cardiovascular Responses of the Pigeon to Sustained, Level Flight in a Wind-Tunnel

Abstract: 1. 1. Five pigeons were trained to fly in a boundary-layer wind-tunnel at a velocity of 10 m s−1 for at least 10 min, and a number of respiratory and cardiovascular variables were recorded. For comparison, heart rate, respiratory frequency and E.M.G. from the pectoralis major muscles were also recorded, using radio-telemetry, from free-flying pigeons. 2. 2. For the flights in the wind tunnel there were immediate increases in respiratory frequency and heart rate upon take-off; these variables continued to increase during the flight, eventually becoming on average 411 breaths min−1 (20 × resting) and 670 beats min−1 (6 × resting) respectively. There was a 1:1 relationship between ventilation and wing beat. Oxygen uptake and carbon dioxide production reached their highest values of 12.5 × and 14.4 × resting respectively within 1 min of take-off and then declined to steady levels of 200 ml kg−1 min S.T.P.D. (10 × resting) and 184 ml kg−1 min S.T.P.D. (10.7 × resting) 4 min after take-off. If allowances are made for the weightand drag of the V OO2 mask and tubes, these stable values are at least 12% higher than would occur in an unloaded bird. Body temperature rose steadily after take-off, reaching a stable value of 43.3°C, which was 2°C above resting, after 6 min of flight. There was a 1.8 × rise in a - v OO2 content difference and little change in cardiac stroke volume during flight, so that the rise in heart rate was the major factor in transporting the extra O2 to the active muscles. Respiratory quotient rose from 0.85 at rest to 0.99, 30 s after take off, and then fell to 0.92 after 7 min of flight. Blood lactate rose to 59.8 mg% (6.5 × its resting value). 3. 3. Comparisons with the free-flying birds indicated that the pattern of flight in the wind tunnel was somewhat abnormal, especially at the beginning of a flight, and this may account for the value of V OO2 being higher at the start of a flight and then declining to a steady value as the flight progressed. 4. 4. Upon landing, heart rate, V· O1 V· CO2 and body temperature began to fall immediately, and within 2 min, heart rate, V· O2 and V· CO2 had returned to the ‘tunnel on’ resting values. Respiratory frequency increased upon landing and its decline closely matched the fall in body temperature. R.Q. rose above unity immediately upon landing as CO2 was removed in excess of its metabolic production, and then fell below the resting value as CO2 was retained, presumably to maintain acid/base balance during the metabolism of lactic acid.

Experimental transient bacteraemias in human subjects with varying degrees of plaque accumulation and gingival inflammation.

Abstract: Ninety-six subjects were assigned to one of four groups according to severity of gingival inflammation and bacterial plaque accumulation on the teeth. Following a standardized toothbrushing procedure, blood specimens from a vein in the antecubital fossa were cultured under aerobic and stringent anaerobic conditions. The percentage of positive cultures increased significantly with increasing severity of gingival inflammation, as did the number of species of organisms isolated. Thirty different microbial species indigenous to the oral cavity, including many strict anaerobes, were recovered. The study has implications for standards of oral health which might be considered necessary in patients with congenital or acquired endocardial defects or cardiovascular prostheses.

Children's production and comprehension of questions

Abstract: This study examined children's production and comprehension of questions, with the aim of discovering possible patterns in question acquisition. For the production study, questions were collected from 22 children aged 2; 0–3; 11. The data show a high frequency of yes-no, what, and where questions by age 2; 0. Why and how questions were infrequent but they increased with age. Who and when questions were rarely asked by children of any age. From the frequency data a rough chronological order of acquisition was inferred: what, where, why, how, when. In the comprehension study 100 children were tested, aged 3; 0–5; 5. The test controlled syntax and vocabulary and varied specific wh- question-words. The frequency of correct answers increased with the age of the children. When children made mistakes, their answers were not random but appeared to be following certain question-answering strategies. These included attention to semantic features of verbs and especially the placement of verbs in the sentence.