Showing papers by "McMaster University published in 1980"
01 Jan 1980
TL;DR: The model of family functioning presented in this article is the product of over twenty years of research in clinical work with family units and is based upon a Judaeo-Christian value set, and allows attention to be paid to cultural differences and other issues of cultural relativity.
Abstract: The model of family functioning being presented is the product of over twenty years of research in clinical work with family units. A method of family therapy has been developed based upon this model and will be described in a future issue. The model utilizes a general systems theory approach in an attempt to describe the structure, organization, and transactional patterns of the family unit. It allows examination of families along the total spectrum ranging from healthy to severely pathological in their functioning. It is based upon a Judaeo-Christian value set, and allows attention to be paid to cultural differences and other issues of cultural relativity.
490 citations
TL;DR: It is suggested that when extramaze stimuli are available, rats tend to use such stimuli in a configurational manner to locate the arms rather than as a list of items processed independently of their spatial relationships to each other.
465 citations
TL;DR: In this article, four pairwise multiple comparison procedures for the case in which the variances in the groups are unequal were compared by computer simulation: the GH procedure based on the Studentized range and the Welch formula for approximate degrees of freedom (df), the C procedure, T2, T3 and T3 were compared.
Abstract: Four pairwise multiple comparison procedures for the case in which the variances in the groups are unequal were compared by computer simulation: the GH procedure based on the Studentized range and the Welch formula for approximate degrees of freedom (df), the C procedure based on a weighted average of two Studentized range points, the T2 procedure based on Student's t, and the T3 procedure based on the Studentized maximum modulus. The results indicate that C, T2, and T3 have the desirable property of being conservative, whereas GH sometimes is not. Of the three conservative procedures, T3 always has shorter confidence interval length than T2, whereas C has shorter length than T3 for large df, but longer length for small df.
460 citations
TL;DR: In this paper, the effect of unequal sample sizes on the error rates of six procedures for pair-wise multiple comparisons with homogeneous variances was studied by computer simulation, and the Tukey-Kramer method was recommended for use in the unequal sample size, homogeneous variance situation.
Abstract: The effect of unequal ni on the error rates of six procedures for pair-wise multiple comparisons beteen k treatment means with homogeneous variances was studied by computer simulation. A commonly used method, attributed to Kramer (1956) but suggested also by Tukey (1953), was found to have error rates less than the nominal value α for several patterns of inequality in the sample sizes, at least when the variations in ni were moderately large. A method that substitutes the harmonic mean sample size for n in Tukey's T method had excessively high error rates. Other methods proposed more recently in the literature were conservative relative to the Tukey-Kramer method. Thus, the Tukey-Kramer method is recommended for use in the unequal sample size, homogeneous variance situation.
344 citations
TL;DR: This article examined different measures of contingency in the psychological judgment literature concerned with binary variables and argued that accurate judgments about related variables should not be used to infer that the judgments are based on the appropriate information.
Abstract: Varied measures of contingency have appeared in the psychological judgment literature concerned with binary variables. These measures are examined, and the inappropriateness of some are noted. As well, it is argued that accurate judgments about related variables should not be used to infer that the judgments are based on the appropriate information.
341 citations
327 citations
TL;DR: Seven healthy male subjects were studied under control conditions and following 5–6 months of heavy resistance training and 5– 6 weeks of immobilization in elbow casts, resulting in a 98% increase in maximal elbow extension strength and a 41% decrease in strength following either training or immobilization.
Abstract: Seven healthy male subjects were studied under control conditions and following 5–6 months of heavy resistance training and 5–6 weeks of immobilization in elbow casts. Cross-sectional fibre areas and nuclei-to-fibre ratios were calculated from cryostat sections of needle biopsies taken from triceps brachii. Training resulted in a 98% increase in maximal elbow extension strength as measured by a Cybex dynamometer, while immobilization resulted in a 41% decrease in strength. Both fast twitch (FT) and slow twitch (ST) fibre areas increased significantly with training by 39% and 31%, respectively. Immobilization resulted in significant decreases in fibre area by 33% for FT and 25% for ST fibres. The observed nuclei-to-fibre ratio was 10% greater following the training programme. However, this change was non-significant. There was also a nonsignificant correlation between the magnitude of the changes in fibre size and the changes in maximal strength following either training or immobilization.
305 citations
TL;DR: This paper investigates the problem of reporting all intersecting pairs in a set of n rectilinearly oriented rectangles in the plane and describes an algorithm that solves this problem in worst case time proportional to n lg n + k, where k is the number of interesecting pairs found.
Abstract: In this paper we investigate the problem of reporting all intersecting pairs in a set of n rectilinearly oriented rectangles in the plane. This problem arises in applications such as design rule checking of very large-scale integrated (VLSI) circuits and architectural databases. We describe an algorithm that solves this problem in worst case time proportional to n lg n + k, where k is the number of interesecting pairs found. This algorithm is optimal to within a constant factor. As an intermediate step of this algorithm, we solve a problem related to the range searching problem that arises in database applications. Although the algorithms that we describe are primarily theoretical devices (being very difficult to code), they suggest other algorithms that are quite practical.
258 citations
TL;DR: Terminal physiological measurements on adult fish succumbing to low pH in soft water indicate the singular importance of iono-regulatory failure as the toxic mechanism of action under these circumstances.
Abstract: The physiological responses of 1- to 2-year-old rainbow trout to low pH are dependent on the environmental calcium concentration. Trout, maintained for 5 days in moderately hard water ([Ca2+] = 1.6-2.7 m-equiv/l) at a mean pH of 4.3, developed a major blood acidosis but exhibited only a minor depression in plasma ion levels. In acidified soft water ([Ca2+] = 0.3 m-equiv/l), only a minor acidosis occurred, but plasma ion levels fell and there were substantially greater mortalities. Lethal bioassays performed on fingerling trout over a range of pH levels (3.0-4.8) revealed an important influence of external [Ca2+] on resistance to acid exposure. Terminal physiological measurements on adult fish succumbing to low pH in soft water indicate the singular importance of iono-regulatory failure as the toxic mechanism of action under these circumstances.
213 citations
TL;DR: The theory of quantum topology as mentioned in this paper has been used for the analysis of molecular topology and its morphogenesis, and it is shown that the quantum mechanical partitioning of a system into subsystems coincides with the topological partitioning: both are defined by a set of zero flux surfaces.
Abstract: In this paper we review and exemplify a new and rigorous approach to the problem of molecular structure and its morphogenesis: the theory of quantum topology. The basis for this approach is provided by the topology of the total charge density in a given molecular system. The essential observation is that the only local maxima of a ground state distribution occur at the positions of the nuclei. The nuclei are therefore identified as point attractors of the gradient vector field of the charge density. The associated basins partition the molecular system into atomic fragments. Each atom is a stable structural unit defined as the union of an attractor and its basin. The common boundary of two neighbouring atomic fragments, the interatomic surface, contains a particular critical point, which generates a pair of gradient paths linking the two neighbouring attractors. The union of this pair of gradient paths and their endpoints is called a bond path. The network of bond paths defines a molecular graph of the system.
Having defined a unique molecular graph for any molecular geometry, the total configuration space is partitioned into a finite number of regions. Each region is associated with a particular structure defined as an equivalence class of molecular graphs. A chemical reaction in which chemical bonds are broken and/or formed is therefore a trajectory in configuration space which must cross one of the boundaries between two neighbouring structural regions. These boundaries form the catastrophe set of the system which, like a phase diagram in thermodynamics, denotes the points of “balance” between neighbouring structures. A general analysis of the structural changes in an ABC type system is given in detail together with specific examples of all possible structural elements in a molecular system.
The properties of the topologically defined atoms and their temporal changes are identified within a general formulation of subspace quantum mechanics. It is shown that the quantum mechanical partitioning of a system into subsystems coincides with the topological partitioning: both are defined by the same set of “zero flux” surfaces. Consequently the total energy, or any other property, is partitioned into additive atomic contributions.
We show that, in general, a definite structure can be assigned to a given molecular system. Quantum mechanically this structure is associated with an open neighbourhood of the most probable nuclear geometry. Finally we generalize the notion of molecular structure to non-isolated molecules and, in contrast to recent work by Woolley, we conclude that molecular structure exists in spite of intermolecular interactions and not as a result of them.
175 citations
TL;DR: A laser absorption spectrometer is described which uses a tunable diode laser and a 1-m multipass White cell to detect NO(2) in air with a sensitivity of better than 100 ppt.
Abstract: A laser absorption spectrometer is described which uses a tunable diode laser and a 1-m multipass White cell to detect NO(2) in air with a sensitivity of better than 100 ppt. The modulation techniques employed to achieve this sensitivity are described in detail, and the noise mechanisms, which currently limit the detectable absorption coefficients to greater, similar 10(-7) m(-1), are examined.
TL;DR: It is shown that the frequency of precursor cells that develop into CTL in the DLN is not reduced, and thus pregnancy suppresses the development of CTL from their precursors.
TL;DR: Observations suggest that there is an accelerated degradation of purine nucleotides to the precursors of uric acid in skeletal muscle during vigorous exercise.
Abstract: This study was designed to examine the influence of exercise on purine metabolism in man. In 15 men, the plasma uric acid concentration increased from 6.9 to 8.5 mg/dl following a 5000-m race and from 6.2 to 7.9 mg/dl in 11 men following a 42-km marathon. During a progressive exercise test on a cycle ergometer, the plasma uric acid ocnentration did not change significantly in 11 subjects. However, the plasma oxypurines increased from 19 micrM at rest to 50 microM at exhaustion and the urinary excretion of oxypurines increased from 140 to 400 mumol/g creatinine. Intracellular ATP decreased from 5.17 to 2.91 mumol/g and ADP and AMP increased from 0.85 to 1.29 and from 0.12 to 0.15 mumol/g wet weight, respectively. These observations suggest that there is an accelerated degradation of purine nucleotides to the precursors of uric acid in skeletal muscle during vigorous exercise.
TL;DR: DNA fragments electrophoresed through a horizontal agarose slab gel can be recovered by inserting strips of filter paper backed by dialysis membrane into slits cut in the gel in front of the DNA bands and continuing Electrophoresis until the DNA is collected in the paper.
TL;DR: In this paper, a numerical procedure is described for modeling the number and distribution of microcracks around a crack tip as a function of the applied stress intensity, and the results indicate that texture can strongly influence the slope of the R curve, and that a positively sloped R curve can be produced by the operation of micro-cracking mechanisms.
Abstract: A numerical procedure is described for modeling the number and distribution of microcracks around a crack tip as a function of the applied stress intensity. The procedure accounts, approximately, for microcrack-microcrack and microcrack-crack interactions. Starting with an array of sites where microcracks can form, the model computes the generation rate of microcracks with increasing stress intensity. The interaction between several neighboring sites leading to extension of the main crack is also apparent and, as a result, an R curve emerges from the calculation. The effects of changing the nature of the microstructural variables inserted into the model can be examined; the results of several calculations with differing microstructural properties are compared. These variables include texture and the statistical distribution of strength over the microcrack sites. The results indicate that texture can strongly influence the slope of the R curve, and the calculations demonstrate that a positively sloped R curve can be produced by the operation of microcracking mechanisms.
TL;DR: In this paper, a theory for important magnetization processes such as magnetic viscosity and the production of a moment on cooling in a magnetic field is presented, where the results for viscous phenomena differ from those obtained by others in that the time dependence of the viscosities depends on the size distribution of the magnetic grains.
Abstract: A theory for important magnetization processes such as magnetic viscosity and the production of a moment on cooling in a magnetic field is presented here. The results for viscous phenomena differ from those obtained by others in that the time dependence of the viscosity depends on the size distribution of the magnetic grains. The moment produced on cooling in a magnetic field is calculated for an arbitrary distribution of grains for the first time. The effect of the cooling rate on the moment produced is found not only to be independent of that distribution but also of the temperature dependence of the saturation magnetization.
TL;DR: The finding of a high respiratory exchange ratio may not exclude the use of fat as a major fuel source in exercise associated with lactate production, and fat metabolism may be controlled to favour adipose tissue lipolysis and extraction of free fatty acids by muscle from the circulation.
Abstract: 1. To investigate differences between the metabolic effects of light and heavy exercise, five healthy males (mean maximal oxygen intake 3.92 litres/min) exercised for 40 min at 36% maximum power (light work) and 70% maximum power (heavy work) on separate days, after an overnight fast. 2. A steady state was achieved in both studies between 20 and 40 min in: oxygen intake (1.42 and 2.64 litres/min respectively); respiratory exchange ratio (0.89 and 1.01); plasma lactate concentration (1.78 and 9.94 mmol/l). 3. Plasma palmitate turnover rate (14C) was unchanged from resting values in light work but was decreased by 40% (from 104 +/- 16 to 63 +/- 8 micronml/min) in heavy work. Heavy work was associated with falls in the plasma concentrations of all free fatty acids measured: palmitic acid (C16:0), oleic acid (C18:1), stearic acid (C18:0), linoleic acid (C18:2) and palmitoleic acid (C16:1). 4. In contrast to th fall in palmitate turnover the increase in plasma glycerol was greater in heavy exercise (0.054-0.229 mmol/l) than in light exercise (0.053-0.094 mmol/l), suggesting that lipolysis was occurring which did not lead to influx of free fatty acids into plasma. 5. In light exercise fat metabolism may be controlled to favour adipose tissue lipolysis and extraction of free fatty acids by muscle from the circulation, whereas in heavy exercise adipose tissue lipolysis is inhibited and hydrolysis of muscle triglycerides may play a more important part. 6. The finding of a high respiratory exchange ratio may not exclude the use of fat as a major fuel source in exercise associated with lactate production.
TL;DR: The methodology of dating intercalated calcareous materials at archaeological sites by dis-equilibrium in the uranium decay series is reviewed for estimating dates of occupation of the sites in this article.
Abstract: The methodology of dating intercalated calcareous materials at archaeological sites by dis-equilibrium in the uranium decay series is reviewed for estimating dates of occupation of the sites Some examples of the method using travertine and artifacts and biological samples from travertine layers are presented
TL;DR: In this article, the authors derived averaged working equations for stratified horizontal flow and analyzed the corresponding local instantaneous two-dimensional equations for propagation of disturbances in stratified flow, showing that the linear stability conditions for long waves are the same for both the averaged and local instantaneous cases.
TL;DR: The present results are consistent with the notion that the supersensitivity to dopamine that occurs in caudate nucleus following 6-hydroxydopamine lesions has both pre- and post-synaptic components in both denervation syndromes.
TL;DR: In the intact attached root and calculated on a protein basis NR, GOGAT, and GS are found to have slightly higher specific activities in the apical 5 mm than in more mature regions of theRoot ofea mays L. GDH and AS, on the other hand, are much more active in extracts prepared from mature areas of the root than in theApical region.
Abstract: The enzymes nitrate reductase (NR), glutamate dehydrogenase (GDH), glutamate synthase (GOGAT), glutamine synthetase (GS) and asparagine synthetase (AS) have been assayed in various regions along the seedling root ofZea mays L. In the intact attached root and calculated on a protein basis NR, GOGAT, and GS are found to have slightly higher specific activities in the apical 5 mm than in more mature regions of the root. GDH and AS, on the other hand, are much more active in extracts prepared from mature regions of the root than in the apical region. In excised root tips incubated in the presence of NH4 (+) and NO3 (-) there was a marked increase in GDH and AS, and a slight decrease in GOGAT and GS. Additions of NO3 (-) are required for NR activity but neither NO3 (-) nor NH4 (+) additions altered the activity levels of the other four enzymes. Additions of glucose to the medium inhibited the development of AS and GDH activities and resulted in higher activity levels of NR, GS and GOGAT. Glucose additions also enhanced the incorporation of acetate-(14)C and leucine-(14)C into protein. Additions of cycloheximide inhibit the development of NR, AS and GDH activities and also the incorporation of acetate-(14)C and leucine into protein.
TL;DR: It is concluded that the rise in PaCO2 during hyperoxia is mainly due to internal diffusive and/or perfusive limitation associated with branchial vasoconstriction, rather than to external convective limitationassociated with the decreased Vw.
TL;DR: Using a sample of 87789 abused and neglected children across the US reported in 1976 to the American Humane Association in Englewood Colorado the authors determine the incidence of child abuse and neglect in relation to household composition family income and victims age.
Abstract: Using a sample of 87789 abused and neglected children across the US reported in 1976 to the American Humane Association in Englewood Colorado the authors determine the incidence of child abuse and neglect in relation to household composition family income and victims age. Abuse and neglect are maximal in father-only homes and minimal in 2-natural-parent homes. Mother-only households exceed those with 1 natural and 1 step-parent in neglect incidence (poverty being the likeliest cause) but the reverse is true for abuse incidence. Poverty is more strongly associated with neglect risk than abuse risk and cannot account for the high risks of abuse and neglect in father-only and step-parent families. The authors suggest that men left alone with children (especially infants in which group and relative risk of the father-only household was especially high) are not adequately prepared emotionally or otherwise to care for them. The presence of an unrelated adult filling a parental role increases the risk of physical abuse but this is unrelated to poverty in the present sample. Rather a specific parental attachment process to newborn children may prevent maltreatment. Most step-parents have not experienced the attachment process and consequently find it difficult to develop genuine affection for their step-children. Both theory and the data presented in this study suggest that in humans as in other animals parental feeling is most readily directed towards own offspring. Considering that reconstituted families are on the increase (according to US Bureau of the Census Paul Glick as of 1976 10% of US children lived in step-parent households) there is need for more research on the parental attachment process and ways of encouraging the redirection of parental feeling.
TL;DR: Colonic electrical control activity was recorded using Teflon-coated stainless steel bipolar electrodes in 15 patients undergoing cholecystectomy who gave informed consent and analysis using the Fast Fourier Transform method revealed a consistent pattern of patterns consistent with the main colonic motor function of temporary storage and mixing.
TL;DR: Four heuristic models are presented here to account for suicide in an evolutionary and sociobiological framework, suggesting that suicide should be tolerated by evolution when it has no effect on the gene pool.
Abstract: Human suicide presents a fundamental problem for the scientific analysis of behavior. This problem has been neither appreciated nor confronted by research and theory. Almost all other behavior exhibited by humans and nonhumans can be viewed as supporting the behaving organism's biological fitness and advancing the welfare of its genes. Yet suicide acts against these ends, and does so more directly and unequivocally than any other form of maladaptive behavior. Four heuristic models are presented here to account for suicide in an evolutionary and sociobiological framework. The first model attributes suicide to the extraordinary development of learning and cultural evolution in the human species. Learning may make human behavior so independent of biological constraints that it can occasionally assume a form entirely contrary to the principles of biological evolution. The second model attributes suicide to a breakdown of adaptive mechanisms in extremely stressful novel environments. The third model involves kin and group selection, arguing that in limited circumstances suicide may occur because of beneficial effects it has on other, surviving individuals who share the suicidal individual's genes. The last model suggests that suicide should be tolerated by evolution when it has no effect on the gene pool. This model holds particular promise in accounting for aspects of suicide not attributable to culture. The evidence indicates that suicide is most common in individuals who are unlikely to reproduce and unable to engage in productive activity; such individuals are least capable of promoting their genes. A complete explanation of suicide may derive only from an analysis of its biological significance.
TL;DR: It is apparent that factors other than intravascular thrombin must play a role in producing the thrombocytopenia of septicemia, and there is frequently little evidence for intrav vascular coagulation in patients with moderate thromBocy Topenia.
TL;DR: It is concluded that the time quantum can be doubled and halved, at least within the doubles set 13, 25, 50, and 100 msec, and is not restricted to the single value of 50 msec as initially proposed.
Abstract: The difference threshold for duration, for the case of empty time intervals bounded by brief auditory pulses, is an increasing function of base duration. For base durations between 100 and 1,480 msec, Weber’s law describes the function quite well and a Weber ratio of .05 is obtained. These results in the present paper conform closely to results that have been reported by others. However, it is further shown that the function changes as the amount of practice is increased at each specific base duration: steps unfold from the linear function, and these steps are clearly evident after 17 consecutive sessions at each base duration. Expressing threshold in terms of the apparent magnitude of the “time quantum,” it is found that q is about 13 msec when base duration is 100 msec and that it jumps to 25 at 200, to 50 at 400, and to 100 at 800. Between the abrupt risers in this step function, the treads are not quite flat, perhaps because the amount of practice was insufficient. It is concluded that the time quantum can be doubled and halved, at least within the doubles set 13, 25, 50, and 100 msec. It is not restricted to the single value of 50 msec as initially proposed (Kristofferson, 1967).
TL;DR: The Archean Timiskaming Group occupies two east-west trending belts in the southeastern part of the Abitibi greenstone belt in northeastern Ontario, and unconformably overlies a thick sequence of submarine mafic-to-felsic volcanic rocks as discussed by the authors.
TL;DR: In this paper, the authors investigated the efficiency of Tiku's modified maximum likelihood estimators for estimating the location and scale parameters of symmetric non-normal distributions, and showed that they are jointly more efficient than x and s for long-tailed distributions.