Showing papers by "University of Sydney published in 1985"
TL;DR: The notion of an acute clinical, immunological, and serological response to infection with ARV which should be considered in the differential diagnosis of mononucleosis-like syndromes in groups at high risk for the development of AIDS is supported.
676 citations
TL;DR: In this paper, the authors show that through-σ-bond interaction can result in decrease of the electron coupling integral J according to a relatively low inverse power law, rather than the exponential falloff with distance expected for 'through-space' interaction.
621 citations
TL;DR: In this paper, the nature of these stability problems is investigated, and a technique using position feedback is considered to solve the problem of low-frequency modes not destabilizing intermediate and higher-order modes.
Abstract: As large space structures are basically distributed systems, serious consideration must be given to the very high order, and consequently very high bandwidth, of these systems. In particular, as practical active control devices such as sensors and actuators have finite bandwidth, great care must be exercised so that control of low-frequency modes does not destabilize the intermediate and higher-order modes. In this paper, the nature of these stability problems is investigated and a technique using position feedback is considered.
394 citations
TL;DR: In this article, the authors examined the impact of happy and sad moods on efficacy judgments concerning a variety of activities and found that emotional states have widespread impact on judgments by making mood-congruent thoughts more available.
Abstract: We examined the impact of happy and sad moods on efficacy judgments concerning a variety of activities. The mood was induced by having hypnotized subjects recall and revive their feelings about a romantic success or failure. Changes in efficacy that these memories induced were not restricted to the romantic domain but were also seen on interpersonal, athletic, and other activities remote from romance. The results suggested that emotional states have widespread impact on judgments by making mood-congruent thoughts more available. Implications for self-efficacy theory and practical applications are discussed.
363 citations
TL;DR: In this article, a time series of 6.5 years of daily observations of beach states and wave characteristics from southeastern Australia was analyzed with the aim of determining the degree to which time-varying beach state can be explained and predicted.
328 citations
TL;DR: In this article, Radiocarbon dating evidence from the South Alligator River, presented here, suggests that extensive mangrove swamps developed between 6,500 and 7,000 yr ago and flourished for about 1,000 years.
Abstract: Mangrove forests in northern Australia typically occur as fringes along tidal estuaries and relatively sheltered coasts. Radiocarbon dating evidence from the South Alligator River, presented here, suggests that extensive mangrove swamps developed between 6,500 and 7,000 yr ago and flourished for about 1,000 yr. Pollen analysis of a stratigraphic core at a mid-plains site links the growth of these forests with the interaction of sea-level change and sedimentation. This was succeeded by the development of flood-plains with tidal river channels, a dramatic ecological change that has implications for all coastal and nearshore systems.
267 citations
TL;DR: A simple continuous-wave Doppler ultrasound system was used to record arterial flow velocity time waveforms from branches of the maternal uterine artery in the placental bed and the fetal umbilical arteries, indicating high resistance in pregnancies with high fetal risk.
255 citations
TL;DR: There is a rapid decline in cell density in the foveal ganglion cell layer toward the end of gestation, and it is suggested that the persistence of high densities in the perifoveal region may be related to migration of cells away from the developing fovea.
Abstract: Neurogenesis in the ventricular layer and the development of cell topography in the ganglion cell layer have been studied in whole-mounts of human fetal retinae. At the end of the embryonic period mitotic figures were seen over the entire outer surface of the retina. By about 14 weeks gestation mitosis had ceased in central retina and differentiation of photoreceptor nuclei was evident within a well-defined area which constituted about 2% of total retina area. This area was approximately centered on the site of the putative fovea, identified by the exclusive development of cone nuclei at that location. The area of retina in which mitosis had ceased increased as gestation progressed. By mid-gestation mitosis in the ventricular layer occupied about 77% of the outer surface of the retina and by about 30 weeks gestation mitosis in the ventricular layer had ceased. Cell density distributions in the ganglion cell layer were nonuniform at all stages studied (14–40 weeks). Densities were highest at about 17 weeks gestation, and by mid-gestation the adult pattern of cell topography was present with maps showing elevated cell densities in posterior retina and along the horizontal meridian. Cell densities generally declined throughout the remainder of the gestation period, except in the posterior retina, where densities in the perifoveal ganglion cell layer remained high during the second half of gestation. There is a rapid decline in cell density in the foveal ganglion cell layer toward the end of gestation, and it is suggested that the persistence of high densities in the perifoveal region may be related to migration of cells away from the developing fovea. The total population of cells in the ganglion cell layer was highest (2.2–2.5 million cells) between about weeks 18 and 30 of gestation. After this the cell population declined rapidly to 1.5–1.7 million cells. It is suggested that naturally occurring neuronal death is largely responsible for this decline.
216 citations
TL;DR: Human platelet glycoprotein Ib is a major integral membrane protein that has been identified as the platelet-binding site mediating the factor VIII/von Willebrand-factor-dependent adhesion of platelets to vascular subendothelium and both GP Ib and GP IX were found to occur in the same immunoprecipitin arc whether the platelets had been solubilized in the absence or presence of the calcium-dependent protease inhibitor, leupeptin.
Abstract: Human platelet glycoprotein Ib (GP Ib) is a major integral membrane protein that has been identified as the platelet-binding site mediating the factor VIII/von Willebrand-factor-dependent adhesion of platelets to vascular subendothelium. Recent evidence suggests that GP Ib is normally complexed with another platelet membrane protein, GP IX. In this study, human platelet plasma membranes were selectively solubilized with a buffer containing 0.1% (v/v) Triton X-100. The GP Ib complex (GP Ib plus GP IX) was purified to homogeneity in ∼ 30% yield by immunoaffinity chromatography of the membrane extract using the anti-(glycoprotein Ib complex) murine monoclonal antibody, WM 23, coupled to agarose. GP Ib and GP IX were subsequently isolated as purified components by immunoaffinity chromatography of the GP Ib complex using a second anti-(glycoprotein Ib complex) monoclonal antibody, FMC 25, coupled to agarose. As assessed by dodecyl sulphate/polyacrylamide gel electrophoresis, purified GP Ib was identical to the molecule on intact platelets and had an apparent relative molecular mass of 170000 under nonreducing conditions and 135000 (α subunit) and 25000 (β subunit) under reducing conditions. GP IX had an apparent Mr of 22000 under both nonreducing and reducing conditions. Purified Gb Ib complex and GP Ib inhibited the ristocetin-mediated, human factor VIII/von Willebrand-factor-dependent and bovine factor VIII/von Willebrand-factor-dependent agglutination of washed human platelets suggesting the proteins had been isolated in functionally active form. GP Ibα had a similar amino acid composition to that previously reported for its proteolytic degradation product, glycocalicin. The amino acid compositions of GP Ibβ and GP IX were similar but showed marked differences in the levels of glutamic acid, alanine, histidine and arginine. The N-termini of GP Ibα and GP IX were blocked; GP Ibβ had the N-terminal sequence, Ile-Pro-Ala-Pro-. On crossed immunoelectrophoresis, both GP Ib and GP IX were found to occur in the same immunoprecipitin arc(s) whether the platelets had been solubilized in the absence or presence of the calcium-dependent protease inhibitor, leupeptin. Binding studies in platelet-rich plasma indicated a similar number of binding sites (x± SD) for three anti-(glycoprotein Ib complex) monoclonal antibodies: AN 51, epitope on GP Ibα (22000 ± 2700, n= 3), WM 23, epitope on GP Ibα (21000 ± 3400, n= 3), FMC 25, epitope on GP IX (20100 ± 2700, n= 3), and FMC 25 (Fab′)2 (27100 ± 800, n= 2). The combined evidence suggests that GP Ib is normally bound to GP IX and that the stoichiometry of this complex is 1:1.
210 citations
TL;DR: This review summarizes available knowledge of the function of the hypothalamic-pituitary gonadal axis in uremia and specific emphasis is directed towards the derangements of testicular function in u Remia and the central as well as gonadal disturbances operative.
Abstract: Introduction THE REGULARITY of gonadal dysfunction in patients with chronic renal failure and in particular the dramatic reversal of hypogonadism after successful renal transplantation are of theoretical and practical interest in the understanding of the regulation of normal and abnormal gonadal function. It is the purpose of this review to summarize available knowledge of the function of the hypothalamic-pituitary gonadal axis in uremia. Specific emphasis is directed towards the derangements of testicular function in uremia and the central as well as gonadal disturbances operative. In addition the parallel abnormalities of the ovarian, thyroidal, adrenal and somatotropin axes in uremia are also considered. Finally, specific factors implicated in the pathogenesis of uremic hypogonadism are evaluated.
202 citations
TL;DR: At least 70% of optic axons generated during development of the primary visual pathway are lost during fetal life, and part of this loss probably occurs as a result of the refinement of the terminal distribution of ganglion cell projections within their target nuclei.
Abstract: We have estimated the number of axons in the optic nerves of human fetuses ranging in gestational age from approximately 10 to 33 weeks. At 10–12 weeks of gestation there were an estimated 1.9 million axons in the optic nerve. A peak count of 3.7 million axons was obtained from a specimen of 16–17 weeks gestation. The estimated number of axons then declined, stabilizing at an estimated 1.1 million axons by about week 29 of gestation. This figure is in close agreement with an estimate of 1.1–1.3 million optic axons in the human adult optic nerve. The results indicate that at least 70% of optic axons generated during development of the primary visual pathway are lost during fetal life. Part of this loss probably occurs as a result of the refinement of the terminal distribution of ganglion cell projections within their target nuclei. The significance of the relatively prolonged period of axonal loss is discussed.
TL;DR: Soybean nodule sucrose synthase had a high affinity for UDP and a relatively low affinity for ADP, and divalent cations stimulated activity in both the cleavage and synthesis directions and the enzyme was very sensitive to inhibition by heavy metals.
Abstract: Sucrose synthase (UDPglucose: d-fructose 2-α-d-glucosyl transferase, EC 2.4.1.13) has been purified from the plant cytosolic fraction of soybean (Glycine max L. Merr cv Williams) nodules. The native enzyme had a molecular weight of 400,000. The subunit molecular weight was 90,000 and a tetrameric structure is proposed for soybean nodule sucrose synthase. Optimum activity in the sucrose cleavage and synthesis directions was at pH 6 and pH 9.5 respectively, and the enzyme displayed typical Michaelis-Menten kinetics. Soybean nodule sucrose synthase had a high affinity for UDP (Km, 5 micromolar) and a relatively low affinity for ADP (apparent Km, 0.13 millimolar) and CDP (apparent Km, 1.1 millimolar). The Km for sucrose was 31 millimolar. In the synthesis direction, UDPglucose (Km, 0.012 millimolar) was a more effective glucosyl donor than ADPglucose (Km, 1.6 millimolar) and the Km for fructose was 3.7 millimolar. Divalent cations stimulated activity in both the cleavage and synthesis directions and the enzyme was very sensitive to inhibition by heavy metals.
TL;DR: In this paper, the authors developed an analytic solution for the fundamental problem of a point heat source buried deep in a saturated soil, where the pore water expands a greater amount than the voids of the soil.
Abstract: When a heat source such as a canister of radioactive waste is buried in a saturated soil the temperature changes that occur will cause the pore water to expand a greater amount than the voids of the soil. The temperature change will thus usually be accompanied by an increase in pore pressure. If the soil is sufficiently permeable these pore pressures will dissipate. This paper develops an analytic solution for the fundamental problem of a point heat source buried deep in a saturated soil.
TL;DR: The prevalence of asthma among adults but not children living in eight South Fore villages of the Eastern Highlands of Papua New Guinea has risen dramatically over the past decade and now is 6 per 1000 in the age group less than 20 years and 73 per 1000 for adults living more than 20 decades as discussed by the authors.
Abstract: The prevalence of asthma among adults but not children living in eight South Fore villages of the Eastern Highlands of Papua New Guinea has risen dramatically over the past decade and now is 6 per 1000 in the age group less than 20 yr and 73 per 1000 in the age group more than 20 yr. Allergy to house dust mites appears to be a significant feature in the disease pathogenesis, and it is likely that this is associated with modifications to traditional lifestyles by the recent introduction of blankets and changes in sleeping habits that promote a more fertile environment for growth and multiplication of mites. Asthma is now provoked by a wide range of factors such as exertion, stress, and antecedent respiratory tract infections, which have always been common features of the South Fore way of life. This suggests that allergic reactivity may be the precursor of bronchial hyperreactivity that, once manifested, can be triggered by a variety of stimuli, not all of which are immunologic in origin.
TL;DR: It was observed following unilateral injection into the PAG, of either the excitatory amino acid, L-aspartic acid or bicuculline, that defensive behaviour was elicited by touching the rat on the body or snout contralateral but not ipsilateral to the injection site, suggesting that the induction of defensive behaviour by unilateral PAG stimulation is due, at least in part, to lateralized alterations in sensorimotor responsiveness.
TL;DR: In this paper, the authors classified rips into three types: erosion, mega and accretion, and observed a total of 3513 rips were observed on 270 days over a 19-month period.
TL;DR: In this paper, a detailed analysis of the relationship between reflective subcategories of a category and factorization systems supported by the category is presented. But the analysis is restricted to a single category.
Abstract: This work is a detailed analysis of the relationship between reflective subcategories of a category and factorization systems supported by the category.
TL;DR: Paired testicular volumes and weights, as well as age, height, and weight, were recorded from a series of 1056 consecutive necropsies on adult males to examine the effects of age, nutritional state (standardized body weight), and illness on testicular size.
Abstract: Paired testicular volumes and weights, as well as age, height, and weight, were recorded from a series of 1056 consecutive necropsies on adult males ranging in age from 18 to 96 years. These data were analyzed to examine the effects of age, nutritional state (standardized body weight), and illness on testicular size. Testicular volume and weight were related by a constant density of 1.038 g/ml, regardless of testicular size, age or illness. Mean testicular volume was correlated with height (r = 0.470), weight (r = 0.504), body surface area (r = 0.549) and standardized body weight (r = 0.152). Advancing age, malnutrition, alcoholism, malignancy, and a chronic, terminal illness were each individual risk factors for reduced testicular size, whereas diabetes, narcotic or other drug usage, and pelvic injury were not associated with reduced testicular volume. Since advancing age, reduced standardized body weight, and some disease states were all associated with diminution of testicular size, the interaction of age, malnutrition, and illness on testicular size were examined by statistical modeling, using multivariate logistic regression and covariance analysis. The associations of alcoholism, malignancy, and chronic, terminal illness with decreased testicular volume were independent of aging or nutritional state. The effects of chronic, terminal illness were mostly explained by the concurrent effects of reductions in standardized body weight (malnutrition). After exclusion of men with diseases shown to be associated with decreased testicular size, he specific effects of age alone demonstrated a reduction in testicular volume only in the 8th decade of life.(ABSTRACT TRUNCATED AT 250 WORDS)
TL;DR: The central projections of different groups of cat retinal ganglion cells were studied following small iontophoretic injections of horseradish peroxidase (HRP) into physiologically characterized sites.
Abstract: The central projections of different groups of cat retinal ganglion cells were studied following small iontophoretic injections of horseradish peroxidase (HRP) into physiologically characterized sites. Analysis was restricted to labeled cells in the upper periphery of the nasal retina, contralateral to the injection site. Injections were made to the A lamina and C lamina of the dorsal lateral geniculate nucleus (LGNd-A,C), the geniculate wing (LGNd-W), the ventral lateral geniculate nucleus (LGNv), the pretectum (PT), and the superior colliculus (SC). The dendritic fields of alpha, beta, and epsilon cells were well labeled by the procedures we employed. A group, termed "g1," had somal sizes within the range of the smaller beta and epsilon cells, but dendritic morphologies distinct from either class. The g1 group may consist of a number of types, but our material provided no basis for further distinguishing them. Many cells were observed that had smaller somas; all had thin axons, and few had dendritic fields that labeled to any significant extent. We were not able to further distinguish these cells, and refer to this group, which may include a number of types, as "g2" cells. From the peripheral nasal retina, alpha cells project to LGNd-A, LGNd-C, PT, and SC. Beta cells project to LGNd-A, LGNd-C, and PT. Epsilon and g1 cells project to the LGNd-C, LGNd-W, LGNv, PT, and SC. We determined the total spatial density of cells in the region of the retina analyzed, using a Nissl-stained preparation. We then estimated the relative fraction of cells in each of the above groupings by injecting HRP throughout a cross section of the optic tract. Multiplying this relative fraction by the total spatial density gave an estimate of the spatial density of each of these groupings. From the spatial density of cells labeled from the injection site, we were able to estimate the fraction of cells of each retinal grouping that project to each of the zones investigated. By these calculations, almost all alpha cells from the upper nasal retina project to LGNd-A and LGNd-C; most project to SC, and about a third to PT. Beta cells, by contrast, project almost exclusively to LGNd-A, with about 10% going to LGNd-C, and about 1% to the PT. The great majority of epsilon cells, if not all, project to LGNd-W, and up to half of this population also project to the other zones noted above.(ABSTRACT TRUNCATED AT 400 WORDS)
TL;DR: It is hypothesized that embryonic moisture tolerances may be an important determinant of breeding seasonality in this region, although some cases do not support this conclusion.
Abstract: Dissection of 1,941 specimens provided data on reproductive cycles in six genera of skinks and three genera of agamids from the Alligator Rivers Region of Australia's Northern Territory. Comparative data on lizards from the temperate zone were gathered by dissecting specimens of three genera, and by reviewing published studies. The Alligator Rivers Region climate exhibits uniformly high temperatures but extremely seasonal rainfall. By analogy with studies on tropical herpetofaunas in other parts of the world, we hypothesised that most species would breed during the wet-season.
TL;DR: Although As has often been included in discussions of heavy metals, I have chosen to exclude it, as well as Se and Te, because it is a nonmetallic element.
Abstract: Much of the information concerning the influences of heavy metals on microorganisms, and the processes they mediate, is fragmentary and scattered over a wide range of scientific literature. This undoubtedly reflects the ubiquitous nature of this very important group of elements, which are characterized by metallic properties and a specific gravity greater than five (Gadd and Griffiths, 1978). Such elements include several essential for the growth, reproduction, and/or survival of all living things, some with no known biological function, and many with economic, industrial, and/or military uses. In all, about 65 elements comply with the definition of a heavy metal (Hammond, 1976). Wood (1974) considered that certain elements could be placed into three categories, each defined in terms of its environmental impact (Table I). For the purposes of this review similar guidelines have been adopted and most attention will be focused upon those metals in category 2. Little emphasis is placed here on interactions with Hg, since this metal was the subject of a recent review by Jeffries (1982). Lastly, although As has often been included in discussions of heavy metals, I have chosen to exclude it, as well as Se and Te, because it is a nonmetallic element (Hawley, 1977).
TL;DR: It is concluded that short-term environmental factors exercise considerable influence on alcohol metabolism, particularly in the absorption phase, and all of the repeatable variance in peak BAC and rate of elimination was due to genetic factors.
Abstract: Blood alcohol measurements were obtained for 206 pairs of twins who had ingested a standard dose of alcohol (0.75 g/kg body weight) and repeat measurements were obtained for 40 of these pairs on a second occasion. The repeatability of the peak blood alcohol concentration (BAC) was 0.66, that of the rate of elimination was 0.39, and that of the time to peak BAC was 0.27. Only a small portion of the nonrepeatable variance could be explained by measurement error or drinking experience. It is concluded that short-term environmental factors exercise considerable influence on alcohol metabolism, particularly in the absorption phase. All of the repeatable variance in peak BAC and rate of elimination was due to genetic factors. Only a small proportion of any of the genetic variance could be explained by individual differences in weight, adiposity, or lung function. Likewise, these three factors were unable to account for the fact that females had higher BACs than males during both absorption and elimination.
TL;DR: In this article, the authors studied the interference response of a tall square building under interference excitation from neighbouring tall buildings in a series of wind-tunnel model tests and found that the interference loads on the upstream of an identical pair of tall buildings may increase by a factor of up to 4.4.
TL;DR: Microphthalmia was the most common malformation at all teratogenic temperatures and was frequently the only malformation seen at the shortest time exposure for a particular temperature.
Abstract: This study determined the relationship between the duration and extent of temperature elevation, during a critical period of rat embryonic development, and the induction of congenital malformations. Pregnant Sprague-Dawley rats, at 9 days 12 hours gestation (gastrulation stage), were partially immersed in a water bath until their core temperature, monitored by a rectal thermistor probe, was elevated to a nominated temperature. Seven temperatures were tested from 40.5 degrees C to 43.5 degrees C, elevations of 2.0-5.0 degrees C in core temperature. Various durations at each of these temperatures were tested for potential teratogenicity. A single elevation of 5.0 degrees C or 4.5 degrees C needed only a "spike" in duration to be teratogenic, 4.0 degrees C was teratogenic within 5 minutes, 3.5 degrees C within 10 minutes, 3.0 degrees C within 20 minutes, and 2.5 degrees C within 1 hour. An elevation of 2.0 degrees C for 8 hours was not teratogenic. Microphthalmia was the most common malformation at all teratogenic temperatures and was frequently the only malformation seen at the shortest time exposure for a particular temperature. Encephalocele, facial clefting, and maxillary hypoplasia were the other frequently seen malformations. Five control rats were placed in the water bath for 2 hours at 38 degrees C so that their core temperature was not elevated. All the control fetuses were normal. An elevation of 2.5 degrees C for 1 hour was the threshold combination for teratogenesis. As the temperature increased above a 2.5 degrees C elevation the necessary duration of exposure for teratogenesis decreased.
TL;DR: In this article, a series of molecules containing an electron donor-acceptor pair interconnected by rigid nonconjugated bridges reveal the occurrence of very fast photoinduced intramolecular electron transfer.
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TL;DR: This is the most comprehensive set of data on food salicylates yet published; extraction appears to have been more complete for some foods, giving higher values than those previously published.
Abstract: To determine salicylate content, 333 food items were analyzed. Foods were homogenized with 25% sodium hydroxide, allowed to stand overnight, acidified with concentrated hydrochloric acid, and then extracted with warm diethyl ether over 5 hours. The extract was dried and taken up in dilute sodium bicarbonate solution for analysis. Salicylic acid was separated by high performance liquid chromatography and quantified by reading at 235 nm. Salicylic acid standards were used throughout to standardize extractions and analyses. This is the most comprehensive set of data on food salicylates yet published; extraction appears to have been more complete for some foods, giving higher values than those previously published. Most fruits, especially berry fruits and dried fruits, contain salicylate. Vegetables show a wide range from 0 to 6 mg salicylate per 100 gm food (for gherkins). Some herbs and spices were found to contain very high amounts per 100 gm, e.g., curry powder, paprika, thyme, garam masala, and rosemary. Among beverages, tea provides substantial amounts of salicylate. Licorice and peppermint candies and some honeys contain salicylates. Cereals, meat, fish, and dairy products contain none or negligible amounts.
TL;DR: Current ideas about the mechanism of upper airway obstruction are reviewed, and the clinical features are discussed in a manner intended to facilitate the clinical assessment of patients with obstructive sleep apnea.
TL;DR: The plant consists of a large number of symplast domains, which may or may not differ in molecular exclusion limit, as well as a set of hydrophilic fluorescent dyes of known molecular weight.
Abstract: A set of hydrophilic fluorescent dyes of known molecular weight has been used to determine the molecular exclusion limit and the extent of apical, epidermal and cortical symplasts in the root, stem and leaf of Egeria densa These dyes are unable to pass the plasmalemma, so that any cell-to-cell movement of injected dye must occur via the symplast The shoot-apex symplast has a high molecular exclusion limit, excluding dyes with a molecular weight of 749 dalton (fluorescein hexaglycine) and greater but allowing dyes of up to 665 dalton (fluorescein diglutamic acid) to pass The leaf epidermal symplast is similar to that in the apex: fluorescein pentaglycine (674 dalton) moves to a limited extent, but fluorescein hexaglycine is immobile Stem and root epidermal cells have a lower molecular exclusion limit, only the dye 6-carboxyfluorescein (376 dalton) is able to move from cell-to-cell Cortical and epidermal tissues in both the stem and the root have similar symplast permeabilities However, a barrier to dye (6-carboxyfluorescein) movement is found between the epidermis and the cortex in both organs Barriers are also found at the nodes between expanded internodes The stem barriers are not found in the unexpanded nodes near the shoot tip; apparently they are formed early during internode expansion In the root tip, a barrier to the movement of dye is found between the root cap and the remainder of the root Plasmodesmata are found linking all cell types studied, even cells where barriers to dye movement occur Thus, the plant, far from being one uniform symplast, consists of a large number of symplast domains, which may or may not differ in molecular exclusion limit
TL;DR: Although significant correlations were found with blood alcohol concentration, previous drinking experience, and the personality trait Extraversion, little of the genetic variance exposed by alcohol could be explained by these predictors.
Abstract: A battery of psychomotor tasks and physiological measures was administered to 206 pairs of twins before alcohol and then three times at hourly intervals after they ingested a standard dose of ethanol (0.75 g/kg body weight). Repeat measurements were obtained for 41 of these pairs on a second occasion. Performance on motor coordination, standing steadiness, pursuit rotor, arithmetic computation, and reaction-time tasks deteriorated after alcohol, but decrements on the five tasks were generally independent of each other. Measurements of blood pressure, pulse rate, and skin temperature were all elevated following alcohol intake, but these responses were also uncorrelated. The variance in many of these measures increased after alcohol. An analysis of covariance structure revealed that most of this additional variance exposed by alcohol was genetic in origin, particularly for standing steadiness, pursuit rotor, arithmetic computation, and pulse rate. Up to 50% of the variance in body sway after alcohol was estimated to be due to genetic factors expressed only under the influence of alcohol. Although significant correlations were found with blood alcohol concentration, previous drinking experience, and the personality trait Extraversion, little of the genetic variance exposed by alcohol could be explained by these predictors. It is concluded that the sources of the considerable genetic variation affecting performance under alcohol must be sought elsewhere.