Showing papers by "Queen's University published in 1992"

Overexpression of a transporter gene in a multidrug-resistant human lung cancer cell line

Abstract: The doxorubicin-selected lung cancer cell line H69AR is resistant to many chemotherapeutic agents. However, like most tumor samples from individuals with this disease, it does not overexpress P-glycoprotein, a transmembrane transport protein that is dependent on adenosine triphosphate (ATP) and is associated with multidrug resistance. Complementary DNA (cDNA) clones corresponding to messenger RNAs (mRNAs) overexpressed in H69AR cells were isolated. One cDNA hybridized to an mRNA of 7.8 to 8.2 kilobases that was 100- to 200-fold more expressed in H69AR cells relative to drug-sensitive parental H69 cells. Overexpression was associated with amplification of the cognate gene located on chromosome 16 at band p13.1. Reversion to drug sensitivity was associated with loss of gene amplification and a marked decrease in mRNA expression. The mRNA encodes a member of the ATP-binding cassette transmembrane transporter superfamily.

Cross-Cultural Psychology: Research and Applications

Abstract: Cross-Cultural Psychology is a leading textbook offering senior undergraduate and graduate students a thorough and balanced overview of the whole field of cross-cultural psychology The team of internationally acclaimed authors present the latest empirical research, theory, methodology and applications from around the world They discuss all domains of behavior (including development, social behavior, personality, cognition, psycholinguistics, emotion and perception), and present the three main approaches in cross-cultural psychology (cultural, culture-comparative, and indigenous traditions) as well as applications to a number of domains (including acculturation, intercultural relations and communication, work and health) With new additions to the writing team, the third edition benefits from an even broader range of cross-cultural perspectives Now in 2-colour, the format is even more reader-friendly and the features include chapter outlines, chapter summaries, further reading and an updated glossary of key terms This edition also offers an accompanying website containing additional material and weblinks

Estuarine facies models; conceptual basis and stratigraphic implications

Abstract: The nature and organization of facies within incised-valley estuaries is controlled by the interplay between marine processes (waves and tides), which generally decrease in intensity up-estuary, and fluvial processes, which decrease in strength down-estuary. All estuaries ideally possess a three-fold (tripartite) structure: an outer, marine-dominated portion where the net bedload transport is headward; a relatively low-energy central zone where there is net bedload convergence; and an inner, river-dominated (but marine-influenced) part where the net transport is seaward. These three zones are not equally developed in all estuaries because of such factors as sediment availability, coastal zone gradient and the stage of estuary evolution. Two distinct but intergradational types of estuaries (wave- and tide-dominated) are recognized on the basis of the dominant marine process. Wave-dominated estuaries typically possess a well-defined tripartite zonation: a marine sand body comprised of barrier, washover, tidal inlet and tidal delta deposits; a fine-grained (generally muddy) central basin; and a bay-head delta that experiences tidal and/or salt-water influence. The marine sand body in tide-dominated estuaries consists of elongate sand bars and broad sand flats that pass headward into a low-sinuosity ("straight") single channel; net sand transport is headward in these areas. The equivalent of the central basin consists of a zone of tight meanders where bedload transport by flood-tidal and river currents is equal in the long term, while the inner, river-dominated zone has a single, low-sinuosity ("straight") channel. These facies models and their conceptual basis provide a practical means of highlighting the differences and similarities between estuaries. They also allow the predication of the stratigraphy of estuarine deposits within a sequence-stratigraphic context.

Endogenous protoporphyrin IX, a clinically useful photosensitizer for photodynamic therapy.

Abstract: The tissue photosensitizer protoporphyrin IX (PpIX) is an immediate precursor of heme in the biosynthetic pathway for heme. In certain types of cells and tissues, the rate of synthesis of PpIX is determined by the rate of synthesis of 5-aminolevulinic acid (ALA), which in turn is regulated via a feedback control mechanism governed by the concentration of free heme. The presence of exogenous ALA bypasses the feedback control, and thus may induce the intracellular accumulation of photosensitizing concentrations of PpIX. However, this occurs only in certain types of cells and tissues. The resulting tissue-specific photosensitization provides a basis for using ALA-induced PpIX for photodynamic therapy. The topical application of ALA to certain malignant and non-malignant lesions of the skin can induce a clinically useful degree of lesion-specific photosensitization. Superficial basal cell carcinomas showed a complete response rate of approximately 79% following a single exposure to light. Recent preclinical studies in experimental animals and human volunteers indicate that ALA can induce a localized tissue-specific photosensitization if administered by intradermal injection. A generalized but still quite tissue-specific photosensitization may be induced if ALA is administered by either subcutaneous or intraperitoneal injection or by mouth. This opens the possibility of using ALA-induced PpIX to treat tumors that are too thick or that lie too deep to be accessible to either topical or locally injected ALA.

The American College of Rheumatology 1991 revised criteria for the classification of global functional status in rheumatoid arthritis.

Abstract: Objective To develop and validate revised criteria for global functional status in rheumatoid arthritis (RA). Methods Revised criteria were formulated and tested for criterion and discriminant validity in 325 patients with RA. Results The revised criteria developed are as follows: class I = able to perform usual activities of daily living (self-care, vocational, and avocational); class II = able to perform usual self-care and vocational activities, but limited in avocational activities; class III = able to perform usual self-care activities but limited in vocational and avocational activities; class IV = limited in ability to perform usual self-care, vocational, and avocational activities. Usual self-care activities include dressing, feeding, bathing, grooming, and toileting; vocational and avocational activities are both patient-desired and age-, and sex-specific. The distribution properties of this classification schema were superior to those of the original Steinbrocker criteria. Mean Health Assessment Questionnaire scores were significantly (P less than 0.0001) different between, and increased across, the 4 classes. Conclusion Although there are limitations inherent in the use of global ordinal scales, the American College of Rheumatology revised criteria will be useful in describing the functional consequences of RA. A more detailed quantitative measure of physical disability should be used, however, for optimal monitoring of patients' clinical status in office practice and clinical research.

Electronic brainstorming and group size

Abstract: Two concurrent experiments were conducted with groups of varying size; there were 2-, 4-, and 6-person groups in one and 6- and 12-person groups in the other We compared the number and quality of

Performance of optical flow techniques

Abstract: The performance of six optical flow techniques is compared, emphasizing measurement accuracy. The most accurate methods are found to be the local differential approaches, where nu is computed explicitly in terms of a locally constant or linear model. Techniques using global smoothness constraints appear to produce visually attractive flow fields, but in general seem to be accurate enough for qualitative use only and insufficient as precursors to the computations of egomotion and 3D structures. It is found that some form of confidence measure/threshold is crucial for all techniques in order to separate the inaccurate from the accurate. Drawbacks of the six techniques are discussed. >

Applications and Properties of Chitosan

Abstract: Chitosan, a polycationic polymer and waste product from the sea food processing industry, is an abundant natural resource that has, as yet, not been fully utilized. Advantages of this polymer include availability, low cost, high biocompatibility, biodegradability and ease of chemical modification. In this paper, the physicochemical properties of chitosan, as well as its numerous applications, are reviewed with particular emphasis on its use in water treat ment, pharmaceutics, agriculture and membrane formation.

Altruism in viscous populations — an inclusive fitness model

Abstract: A viscous population (Hamilton, 1964) is one in which the movement of organisms from their place of birth is relatively slow This viscosity has two important effects: one is that local interactions tend to be among relatives, and the other is that competition for resources tends to be among relatives The first effect tends to promote and the second to oppose the evolution of altruistic behaviour In a simulation model of Wilsonet al (1992) these two factors appear to exactly balance one another, thus opposing the evolution of local altruistic behaviour Here I show, with an inclusive fitness model, that the same result holds in a patchstructured population

Quantification of adipose tissue by MRI: relationship with anthropometric variables

Abstract: This study had two objectives: 1) to establish magnetic resonance imaging (MRI) as a tool for measuring total and regional adipose tissue (AT) distribution in humans and 2) to assess the relationship between selected anthropometric variables and MRI-measured AT. Twenty-seven healthy men varying in age [40.8 +/- 14.5 (SD) yr], body mass index (28.5 +/- 4.8), and waist-to-hip ratio (WHR, 0.96 +/- 0.07) participated in the study. Total AT volume was determined using a linear interpolation of AT areas obtained on consecutive slices (n = 41) taken from head to toe (10-mm thickness, 50-mm centers). The mean change for repeated measures of total AT volume was 2.9% (range 0.9-–4.3%). Large interindividual differences were observed for total AT volume (6.9–59.3 liters), subcutaneous AT (6.3–49.8 liters), and visceral AT (0.5–8.5 liters). Visceral AT represented 18.3% of the total AT. The single best predictor of total adiposity was waist circumference (R2 = 0.92). For visceral AT volume, WHR was the strongest anth...

Narrating our Pasts: The Social Construction of Oral History

Abstract: This study looks at how oral histories are constructed and how they should be interpreted, and argues for a deeper understanding of their oral and social characteristics. Oral accounts of past events are also guides to the future, as well as being social activities in which tellers claim authority to speak to particular audiences. Like written history and literature, orality has its shaping genres and aesthetic conventions and, likewise, has to be interpreted through them. The argument is illustrated through a wide range of examples of memory, narration and oral tradition, including many from Europe and the Americas, and with a particular focus on oral histories from the Jlao Kru of Liberia, with whom Elizabeth Tonkin has carried out extensive research. Tonkin also draws on and integrates the insights of a range of other disciplines, such as literary criticism, linguistics, history, psychology, and communication and cultural studies.

Performance assessment measures for univariate feedback control

Abstract: A normalized performance index, η(b), is introduced to characterize the performance of feedback control schemes. η(b) is attractive because it provides a measure of the proximity of control to minimum variance control, which is the optimal feedback control provided that the process can be described by a linear transfer function with additive disturbance. Both time domain and spectral interpretations of this performance index are discussed. A fast, simple, on-line method for estimating η(b) is given, along with some of the statistical properties of the estimator. Simulation and industrial examples demonstrate the utility of η(b/) On presente un indice de performance normalise, η(b) afin de caracteriser la performance de schemas de controle de retroaction. Cet indice η(b) est interessant car il fournit une mesure de la proximite du controle par rapport au controle de variance minimum, qui constitue le controle de retroaction optimal dans la mesure ou ce procede peut etre decrit par une fonction de transfert lineaire avec une perturbation supplementaire. On examine tant le domaine de temps que les interpretations spectrales de cet indice de performance. On presente une methode rapide, simple et en ligne pour l'estimation de η(b) ainsi que certaines des proprietes statistiques de l'estimateur. Des cas de simulation et des exemples industriels demontrent l'utilite de η(b).

Growth hormone treatment of adults with growth hormone deficiency: results of a 13-month placebo controlled cross-over study.

Abstract: OBJECTIVE We aimed to study the effect of biosynthetic growth hormone (GH) replacement in growth hormone deficient adults. DESIGN We performed a double-blind placebo-controlled cross-over study of 6 months biosynthetic GH, replacement and 6 months placebo separated by a 1-month's washout period. PATIENTS Fourteen growth hormone deficient adults were studied. MEASUREMENTS We measured total body weight, percentage fat mass, lean body mass, muscle volume, exercise capacity, maximum oxygen consumption, muscle strength, bone mineral content, a number of biochemical parameters, IGF-I, GH antibodies and psychological well-being. RESULTS Total body weight remained unchanged, but lean body mass increased (before GH mean +/- SEM 49.8 +/- 5.5, after 53.4 +/- 5.6 kg; placebo before 51.2 +/- 5.4, after 50.4 +/- 5.1 kg; P less than 0.05 and fat mass decreased (before GH 21.5 +/- 4.1, after 19.3 +/- 4.3; placebo before 19.3 +/- 4.0, after 22.5 +/- 4.5 kg; P less than 0.05). Thigh muscle volume increased: (before GH 94.1 +/- 7.7, after 99.5 +/- 8.4 ml; placebo before 99.3 +/- 8.6, after 95.4 +/- 7.8 ml/0.8 mm computerized tomographic slice; P less than 0.05). Exercise capacity increased (before GH 174 +/- 15, after 199 +/- 18.9 watts; placebo before 162.5 +/- 2.3, after 154 +/- 19.8 watts; P less than 0.05), as did maximum oxygen consumption (before GH 1.93 +/- 0.2, after 2.17 +/- 0.2 l/m; placebo before 1.92 +/- 0.3, after 1.98 +/- 0.2 l/m; P less than 0.05). There was no change in quadriceps muscle strength. Alkaline phosphatase increased (before GH 87.5 (32-158), after 106.0 (49-179) U/I, placebo 99.5 (50-145), after 72.0 (40-111) U/I; P less than 0.05) without a change in the spinal bone density. IGF-I increased (before GH 62 (36-97), after 216 (62-362) micrograms/l; placebo before 59 (52-112), after 60.5 (38-94) micrograms/l; P less than 0.05). Carbohydrate tolerance remained unchanged as did fasting lipids, serum sodium, potassium, urea, calcium, phosphate and liver transaminases. Psychological well-being remained unchanged. No growth hormone antibodies were detected before or after GH treatment. CONCLUSIONS GH alters the body composition of growth hormone deficient adults and leads to improved exercise capacity; alkaline phosphatase activity increases but without a change in spinal bone density, and carbohydrate tolerance remains unaltered.

A weighted—averaging regression and calibration model for inferring total phosphorus concentration from diatoms in British Columbia (Canada) lakes

Abstract: SUMMARY 1. The relationship between surficial sediment diatom taxa (Bacillariophyceae) and measured limnological variables in forty-six British Columbia lakes was explored using canonical correspondence analysis (CCA). Lake-water total phosphorus concentration (TP), maximum lake depth, conductivity, and calcium concentration each accounted for independent and statistically significant directions of variation in the distribution of diatom taxa. 2. Weighted-averaging (WA) models were developed to infer lake-water TP from the relative abundances of 131 diatom taxa in the surficial sediments of thirty-seven lakes. WA regression and calibration with classical deshrinking provided the best model for TP reconstructions. 3. Our quantitative inference model has two major advantages over existing multiple linear-regression models: (i) inferences are based on the responses of individual taxa to TP, and do not involve grouping the taxa into a small number of ecological categories; and (ii) the model assumes that diatoms respond to TP in a unimodal, rather than a linear, fashion. 4. The WA model can now be used to infer past lake-water TP, within the range 5–28νgr1−1, from diatoms preserved in the sediments of British Columbia lakes. The model can provide quantitative estimates of the onset, rate, and magnitude of lake eutrophication in response to natural processes and human disturbances.

Costs of Sexual Selection in Natural Populations of Mammals

Abstract: Models of sexual selection typically assume a cost to the production and maintenance of sexually selected traits. However, within a population, individuals of high phenotypic quality may not only show greater expression of the trait but may also have higher survival rates. In such a case, the true cost of the trait may be difficult to detect. Comparative studies can circumvent some of the difficulties inherent in intraspecific studies. In this study, I used a comparative approach to examine the relation between sexual size dimorphism and adult mortality in natural populations of mammals. After controlling for the effects of phylogeny, I found that the degree of male-bias in adult mortality was positively correlated with the degree of sexual size dimorphism across taxa. This is the first comparative evidence for a cost of sexually selected traits in natural populations of mammals. In contrast to the general rule that mortality in mammals is male-biased, I also found that it is frequently female-biased in monogamous taxa of mammals. I suggest that in monogamous species the cost of reproduction to females will be similar to that of polygynous species. However, males of monogamous species will be spared the costs of male-male competition and dimorphic growth. This decrease in male costs relative to females may then lead to a female-bias in mortality.

Time to collision is signalled by neurons in the nucleus rotundus of pigeons.

Abstract: Throughout the animal kingdom, the sight of a rapidly approaching object usually signals danger and elicits an escape response. Gibson suggested that the symmetrical expansion of an object's image (looming) is the critical variable determining that the object is on a collision course with the observer. Similarly, large expanding flow-fields like those produced by locomotion may precipitate manoeuvres such as turning or landing. From such observations it has been shown that the optic flow parameter, tau, which specifies time to contact with the approaching object best fits the behavioural data. We describe a subpopulation of neurons in the nucleus rotundus of the pigeon brain that respond selectively to objects moving on a collision course towards the bird.

Mortality costs of sexual dimorphism in birds

Abstract: Sexually selected traits provide a mating advantage to the bearer but they should also exact a cost through natural selection. Whereas the mating benefits from such traits have been well documented, the costs have been difficult to demonstrate. In this analysis of mortality patterns across 28 North American passerine bird species, we show that sex-biased mortality (log 10 male mortality – log 10 female mortality) is positively correlated with both sexual size dimorphism and male plumage brightness. Male (but not female) mortality is positively correlated with sexual size dimorphism, suggesting a cost to male–male competition. Female (but not male) mortality is negatively correlated with male brightness, and we argue from this that the evolution of male brightness has been constrained by mortality costs. Thus sexual dimorphism in body size and plumage colour within bird species appears to be influenced by the opposing forces of sexual selection, acting to increase dimorphism, and adult mortality rates, which constrain the evolution of these traits. Differences in the expression of ornamental traits across species may be explained not only by variation in the mating benefits that accrue from ornaments, as is so often assumed, but also by variation in the costs of these traits.

Paleolimnology: an important tool for effective ecosystem management

Abstract: Effective management of aquatic resources requires long-term environmental data. However, because long-term observations are rarely available, indirect proxy methods must be used to substitute for these missing historical data sets. Major advances have been made in paleolimnology over the last decade, and many of these advances can be applied directly to integrated and cost-effective assessments of aquatic ecosystem health. This commentary uses the analogy of human health to argue that paleolimnological data provide information crucial to the decision-making processes of ecosystem managers.

Deviations from hall-petch behaviour in as-prepared nanocrystalline nickel

Abstract: 2,106,004 1/1938 Inglee .................................. 204/300 R 2,764,540 9/1956 Farin et al. .......................... 204/1297 3,103,235 9/1963 Stringham ................................. 138/97 3,125,464 3/1964 Harmes ................................... 18/105 3,287,248 11/1966 Braithwaite ............................. 204/260 3,618,639 11/1971 Daley et al. ............................ 137/28 3,673,073 6/1972 Tobey et al. ............................ 204/226 3,804,725 4/1974 Haynes .................................... 205/104 4,080,268 3/1978 Suzuki et al. ........................... 205/131 4,120,994 10/1978 Inoue ...................................... 427/239 4,200,674 4/1980 Inoue ...................................... 427/290 4,227,986 10/1980 Loqvist et al. .......................... 204/209 4,280,882 7/1981 Hovey ....................................... 205/50

Predictive testing for Huntington disease in Canada: adverse effects and unexpected results in those receiving a decreased risk.

Abstract: By January 1, 1991, a total of 388 persons had enrolled in the Canadian collaborative study of predictive testing for Huntington disease (HD). Of these participants, 105 persons have been given a decreased risk result. Contrary to expectations, approximately 10% of persons with a decreased risk result have had psychological difficulties coping with their new status. Here, we describe the individual responses of 6 such persons and experimental themes emerging after following these persons for up to 2 years. Individuals who are more likely to suffer an adverse reaction to a decreased risk result include those persons who have made irreversible decisions based on the belief they would develop HD or those who had unrealistic overoptimistic expectations of the positive effects of a decreased risk result. In contrast to those receiving an increased risk result, the most vulnerable time for persons receiving a decreased risk result is between 2 and 12 months after learning the outcome. The need for assessment and counselling of participants in predictive testing programs, even when there is a decreased risk result, is emphasized.

Sperm size and sperm competition in birds.

Abstract: In a sample of 20 species of North American passerine birds we found no relation between sperm size and mating system like that previously reported in mammals (Gomendio & Roldan (Proc. R. Soc. Lond. B 243, 181 (1991)). Instead, we found a positive correlation between sperm length and the length of female sperm storage tubules (SSTS) and a negative correlation between sperm length and the number of SSTS. Both of these correlations suggest that the more than fivefold variation in sperm size we found among species can be explained by sperm competition for access to storage sites (SSTS) in females. As longer sperm appear to be able to swim faster, selection should favour long sperm when SSTS are in short supply; sperm long enough to fill an SST might also prevent access to SSTS by the sperm of other males. Conversely, selection should favour shorter sperm when there is an advantage to sperm layering within an SST promoting a last-male mating advantage. Although we conclude that sperm competition influences sperm size in birds, little is known about the interactions between sperm and SSTS. It seems clear, however, that detailed study of this interaction will provide a new dimension to the study of avian mating systems.

Corticospinal projections to lower limb motoneurons in man

Abstract: The projections of cortical neurons activated by transcranial magnetic stimulation to single lower limb spinal motoneurons were examined in 34 normal subjects. Peristimulus time histograms of the discharge times of single, voluntarily activated motor units were used to derive information about postsynaptic potentials in single spinal motoneurons produced by magnetic stimuli applied over the contralateral scalp. All tibialis anterior motor units and the majority of motoneurons innervating the small muscles of the foot showed strong short latency facilitation. About half of the motoneurons of proximal lower limb muscles showed this facilitation. Short latency facilitation of the motoneurons of soleus and medial gastrocnemius was only rarely observed and when present was weak. The short latency facilitation is attributed to the projections of the fast corticospinal pathway with monosynaptic projections to motoneurons. The relative strength of the facilitation in different motoneuron pools is considered to reflect the density of corticospinal projections to that motoneuron pool. The observed pattern of projections in man shows some differences from the pattern of projections in subhuman primates that might reflect the different use of the limb.

Enhanced synthesis of neutrophil-activating peptide-I/interleukin-8 in active ulcerative colitis

Abstract: 1. We studied neutrophil-activating peptide-1/interleukin-8 in inflammatory bowel disease. 2. Mucosal levels of neutrophil-activating peptide-1/interleukin-8 were significantly higher in patients with active ulcerative colitis [median 74.5 (range 17.7-450.8) pg/mg] than in patients with active Crohn's disease [10.4 (4-46.9) pg/mg; P less than 0.002] or in normal control subjects [10.4 (4-16.6) pg/mg; P less than 0.002]. 3. Circulating neutrophil-activating peptide-1/interleukin-8 was generally undetectable but there were higher levels of anti-neutrophil-activating peptide-1/interleukin-8 antibodies in patients with active ulcerative colitis [62.9 (3.4-239) ng/ml] than in patients with active Crohn's disease [5.9 (2.1-18.10) ng/ml; P less than 0.001] or in control subjects [6.1 (3.2-15.8) ng/ml; P less than 0.001]. 4. Neutrophil-activating peptide-1/interleukin-8 may be of specific functional importance in mediating inflammation in ulcerative colitis.

Adult Tactile Stimulation during Face-to-Face Interactions Modulates Five-Month-Olds' Affect and Attention

Abstract: 3 studies were designed to investigate infant responses to tactile stimulation during brief adult-infant interaction using a modified still-face (SF) procedure. When adults pose a neutral SF expression, infants decrease gazing and smiling at the adults, and some increase grimacing, relative to normal interaction periods. This SF effect was substantially reduced in Study 1 when mothers or strangers continued to touch infants during the SF period. In Studies 2 and 3, tactile versus visual and active versus passive aspects of adult touch were isolated during different SF periods. Visible, active adult hands unaccompanied by touch elicited infant attention, but not smiling, during the SF period. By contrast, active, not passive, adult touch substantially reduced the SF effect, even when the adult's hands were invisible. In the latter condition, infants continued to gaze and smile at the adult's SF. Thus, adult facial expressions are not the only modulator of infant affect and attention during social exchanges; adult touch appears to play an active role.