Showing papers by "Boston University published in 1992"

Fuzzy ARTMAP: A neural network architecture for incremental supervised learning of analog multidimensional maps

Abstract: A neural network architecture is introduced for incremental supervised learning of recognition categories and multidimensional maps in response to arbitrary sequences of analog or binary input vectors, which may represent fuzzy or crisp sets of features. The architecture, called fuzzy ARTMAP, achieves a synthesis of fuzzy logic and adaptive resonance theory (ART) neural networks by exploiting a close formal similarity between the computations of fuzzy subsethood and ART category choice, resonance, and learning. Four classes of simulation illustrated fuzzy ARTMAP performance in relation to benchmark backpropagation and generic algorithm systems. These simulations include finding points inside versus outside a circle, learning to tell two spirals apart, incremental approximation of a piecewise-continuous function, and a letter recognition database. The fuzzy ARTMAP system is also compared with Salzberg's NGE systems and with Simpson's FMMC system. >

Research on Women Business Owners: Past Trends, a New Perspective and Future Directions

Abstract: The number of women starting and owning their own businesses has grown dramatically over the past decade. Concurrent with this trend, there has been an increase in the number of research studies fo...

Phase behaviour of metastable water

Abstract: THE metastable extension of the phase diagram of liquid water exhibits rich features that manifest themselves in the equilibrium properties of water. For example, the density maximum at 4 °C and the minimum in the isothermal compressibility at 46 °C are thought to reflect the presence of singularities in the behaviour of thermodynamic quantities occurring in the supercooled region1 2. The 'stability–limit conjecture'3–5 suggests that these thermodynamic anomalies arise from a single limit of mechanical stability (spinodal line), originating at the liquid–gas critical point, which determines the limit of both superheating at high temperatures and supercooling at low temperatures. Here we present a comprehensive series of molecular dynamics simulations which suggest that, instead, the supercooling anomalies are caused by a newly identified critical point, above which the two metastable amorphous phases of ice (previously shown to be separated by a line of first-order transitions6,7) become indistinguishable. The two amorphous ice phases are thus incorporated into our understanding of the liquid state, providing a more complete picture of the metastable and stable behaviour of water.

Long-range correlations in nucleotide sequences

Abstract: DNA sequences have been analysed using models, such as an n-step Markov chain, that incorporate the possibility of short-range nucleotide correlations. We propose here a method for studying the stochastic properties of nucleotide sequences by constructing a 1:1 map of the nucleotide sequence onto a walk, which we term a 'DNA walk'. We then use the mapping to provide a quantitative measure of the correlation between nucleotides over long distances along the DNA chain. Thus we uncover in the nucleotide sequence a remarkably long-range power law correlation that implies a new scale-invariant property of DNA. We find such long-range correlations in intron-containing genes and in nontranscribed regulatory DNA sequences, but not in complementary DNA sequences or intron-less genes.

To be fully there: Psychological presence at work.

Abstract: This article develops the concept of psychological presence to describe the experiential state enabling organization members to draw deeply on their personal selves in role performances, i.e., express thoughts and feelings, question assumptions, innovate. The dimensions of psychological presence are described along with relevant organizational and individual factors. The concept's implications for theory and research about the person-role relationship are described.

Labor Supply Flexibility and Portfolio Choice in a Life-Cycle Model

Abstract: This paper examines the effect of the labor-leisure choice on portfolio and consumption decisions over an individual's life cycle. The model incorporates the fact that individuals may have considerable flexibility in varying their work effort (including their choice of when to retire). Given this flexibility, the individual simultaneously determines optimal levels of current consumption, labor effort, and an optimal financial investment strategy at each point in his life cycle. We show that labor and investment choices are intimately related. The ability to vary labor supply ex post induces the individual to assume greater risks in his investment portfolio ex ante. The model explains why the young (enjoying greater labor flexibility over their working lives) may take greater investment risks than the old. It also offers an explanation as to why consumption spending is relatively "smooth" despite volatility in asset prices. Finally, the paper provides a compact method for valuing the risky cash flows associated with future wage income.

Recombinant tissue plasminogen activator in acute thrombotic and embolic stroke

Abstract: An open angiography-based, dose rate escalation study on the effect of intravenous infusion of recombinant tissue plasminogen activator (rt-PA) on cerebral arterial recanalization in patients with acute focal cerebral ischemia was performed at 16 centers. Arterial occlusions consistent with acute ischemia in the carotid or vertebrobasilar territory in the absence of detectable intracerebral hemorrhage were prerequisites for treatment. After the 60-minute rt-PA infusion, arterial perfusion was assessed by repeat angiography and computed tomography scans were performed at 24 hours to assess hemorrhagic transformation. Of 139 patients with symptoms of focal ischemia, 80.6% (112) had complete occlusion of the primary vessel at a mean of 5.4 +/- 1.7 hours after symptom onset. No dose rate response of cerebral arterial recanalization was observed in 93 patients who completed the rt-PA infusion. Middle cerebral artery division (M2) and branch (M3) occlusions were more likely to undergo recanalization by 60 minutes than were internal carotid artery occlusions. Hemorrhagic infarction occurred in 20.2% and parenchymatous hematoma in 10.6% of patients over all dose rates, while neurological worsening accompanied hemorrhagic transformation (hemorrhagic infarction and parenchymatous hematoma) in 9.6% of patients. All findings were within prospective safety guidelines. No dose rate correlation with hemorrhagic infarction, parenchymatous hematoma, or both was seen. Hemorrhagic transformation occurred significantly more frequently in patients receiving treatment at least 6 hours after symptom onset. No relationship between hemorrhagic transformation and recanalization was observed. This study indicates that site of occlusion, time to recanalization, and time to treatment are important variables in acute stroke intervention with this agent.

AIMS2. The content and properties of a revised and expanded Arthritis Impact Measurement Scales Health Status Questionnaire.

Abstract: Objective. The goal of this project was to develop a more comprehensive and sensitive version of the Arthritis Impact Measurement Scales (AIMS). Methods. AIMS scale items were revised, and 3 new scales were added to evaluate arm function, work, and social support. Sections were also added to assess satisfaction with function, attribution of problems to arthritis, and self-designation of priority areas for improvement. The new instrument was designated the AIMS2. A pilot test of format and content and a performance test of reliability and validity were carried out. Results. Questionnaire completion times in a pilot study of 24 subjects averaged 23 minutes, and evaluations were positive regarding the instrument's length and ease of completion, and the subjects' willingness to complete serial forms and return them by mail. Measurement performance was tested in 408 subjects: 299 with rheumatoid arthritis (RA) and 109 with osteoarthritis (OA); 45 of these subjects completed a second AIMS2 within 3 weeks. Internal consistency coefficients for the 12 scales were 0.72—0.91 in the RA group and 0.74—0.96 in the OA group. Test-retest reliability was 0.78—0.94. All within-scale factor analyses produced single factors, except for mobility level in OA. Validity analyses in both the RA and the OA groups showed that patient designation of an area as a problem or as a priority for improvement was significantly associated with a poorer AIMS2 scale score in that area. Reliability, factor analysis, and validity results were consistent in age, sex, and education subgroups. Satisfaction was moderately correlated with level of function in the same health status area, and the satisfaction items formed a reliable scale. Responses to the arthritis attribution items showed that most dysfunction in this sample was due to arthritis. Conclusion. The AIMS2 is a revised and expanded health status questionnaire with excellent measurement properties that should be useful in arthritis clinical trials and in outcomes research.

Weight loss reduces the risk for symptomatic knee osteoarthritis in women. The Framingham Study.

Abstract: Objective To evaluate the effect of weight loss in preventing symptomatic knee osteoarthritis in women. Design Cohort analytic study. Setting The Framingham Study, based on a sample of a defined population. Patients Women who participated in the Framingham Knee Osteoarthritis Study (1983 to 1985): Sixty-four out of 796 women studied had recent-onset symptomatic knee osteoarthritis (knee symptoms plus radiographically confirmed osteoarthritis) were compared with women without disease. Measurements Recalled date of symptom onset was used as the incident date of disease. Historical weight was defined as baseline body mass index up to 12 years before symptom onset. Change in body mass index was assessed at several intervals before the current examination. Odds ratios assessing the association between weight change and knee osteoarthritis were adjusted for age, baseline body mass index, history of previous knee injury, habitual physical activity level, occupational physical labor, smoking status, and attained education. Results Weight change significantly affected the risk for the development of knee osteoarthritis. For example, a decrease in body mass index of 2 units or more (weight loss, approximately 5,1 kg) over the 10 years before the current examination decreased the odds for developing osteoarthritis by over 50% (odds ratio, 0.46; 95% Cl, 0.24 to 0.86; P = 0.02). Among those women with a high risk for osteoarthritis due to elevated baseline body mass index (greater than or equal to 25), weight loss also decreased the risk (for 2 units of body mass index, odds ratio, 0.41; P = 0.02). Weight gain was associated with a slightly increased risk for osteoarthritis, which was not statistically significant. Conclusion Weight loss reduces the risk for symptomatic knee osteoarthritis in women.

Geometric-optical bidirectional reflectance modeling of the discrete crown vegetation canopy: effect of crown shape and mutual shadowing

Abstract: In the case where a vegetation cover can be regarded as a collection of individual, discrete plant crowns, the geometric-optical effects of the shadows that the crowns cast on the background and on one another strongly condition the brightness of the vegetation cover as seen from a given viewpoint in the hemisphere. An asymmetric hotspot, in which the shape of the hotspot is related to the shape of the plant crowns in the scene, is created. At large zenith angles illumination shadows will preferentially shadow the lower portions of adjacent crowns. Further, these shadows will be preferentially obscured since adjacent crowns will also tend to obscure the lower portions of other crowns. This effect produces a 'bowl-shaped' bidirectional reflectance distribution function (BRDF) in which the scene brightness increases at the function's edges. Formulas describing the hotspot and mutual-shadowing effects are derived, and examples that show how the shape of the BRDF is dependent on the shape of the crowns, their density, their brightness relative to the background, and the thickness of the layer throughout which the crown centers are distributed are presented. >

Subduction zone infancy: Examples from the Eocene Izu-Bonin-Mariana and Jurassic California arcs

Abstract: A new model for the earliest stages in the evolution of subduction zones is developed from recent geologic studies of the Izu-Bonin-Mariana (IBM) arc system and then applied to Late Jurassic ophiolites of Cailfornia. The model accounts for several key observations about the earliest stages in the evolution of the IBM system: (1) subduction nucleated along an active transform boundary, which separated younger, less-dense lithosphere in the west from older, more-dense lithosphere to the east; (2) initial arc magmatic activity occupied a much broader zone than existed later; (3) initial magmatism extended up to the modern trench, over a region now characterized by subnormal heat flow; (4) early are magmatism was characterized by depleted (tholeiitic) and ultra-depleted (boninitic) magmas, indicating that melting was more extensive and involved more depleted mantle than is found anywhere else on earth; (5) early arc magmatism was strongly extensional, with crust forming in a manner similar to slow-spreading ridges; and (6) crust production rates were 120 to 180 km 3 /km-Ma, several times greater than for mature arc systems. These observations require that the earliest stages of subduction involve rapid retreat of the trench; we infer that this resulted from continuous subsidence of denser lithosphere along the transform fault. This resulted in strong extension and thinning of younger, more buoyant lithosphere to the west. This extension was accompanied by the flow of water from the sinking oceanic lithosphere to the base of the extending lithosphere and the underlying asthenosphere. Addition of water and asthenospheric upwelling led to catastrophic melting, which continued until lithosphere subsidence was replaced by lithospheric subduction . Application of the subduction-zone infancy model to the Late Jurassic ophiolites of California provides a framework in which to understand the rapid formation of oceanic crust with strong arc affinities between the younger Sierran magmatic arc and the Franciscan subduction complex, provides a mechanism for the formation and subsidence of the Great Valley forearc basin, and explains the limited duration of high-T, high-P metamorphism experienced by Franciscan melanges.

The heart in hypertension.

Abstract: HYPERTENSIVE heart disease can be defined as the response of the heart to the afterload imposed on the left ventricle by the progressively increasing arterial pressure and total peripheral resistance produced by hypertensive vascular disease. Although the response sometimes appears to be out of proportion to the level of the arterial pressure, it is primarily the result of the hemodynamic overload. Hypertension can cause or is related to various cardiac manifestations, among them left ventricular hypertrophy, congestive heart failure, cardiac dysrhythmias, and ischemic heart disease. Although the risk of atherosclerotic coronary heart disease is related to the systolic and diastolic . . .

Time and the Observer: the Where and When of Consciousness in the Brain

Abstract: We compare the way two models of consciousness treat subjective timing. According to the standard “Cartesian Theater” model, there is a place in the brain where “it all comes together,” and the discriminations in all modalities are somehow put into registration and “presented” for subjective judgment. The timing of the events in this theater determines subjective order. According to the alternative “Multiple Drafts” model, discriminations are distributed in both space and time in the brain. These events do have temporal properties, but those properties do not determine subjective order because there is no single, definitive “stream of consciousness,” only a parallel stream of conflicting and continuously revised contents. Four puzzling phenomena that resist explanation by the Cartesian model are analyzed: (1) a gradual apparent motion phenomenon involving abrupt color change (Kolers & von Grunau 1976), (2) an illusion of an evenly spaced series of “hops” produced by two or more widely spaced series of taps delivered to the skin (Geldard & Sherrick's “cutaneous rabbit” [1972]), (3) backwards referral in time, and (4) subjective delay of consciousness of intention (both reported in this journal by LIbet 1985a; 1987; 1989a). The unexamined assumptions that have always made the Cartesian Theater so attractive are exposed and dismantled. The Multiple Drafts model provides a better account of the puzzling phenomena, avoiding the scientific and metaphysical extravagances of the Cartesian Theater: The temporal order of subjective events is a product of the brain's interpretational processes, not a direct reflection of events making up those processes.

Neuroblastoma x spinal cord (NSC) hybrid cell lines resemble developing motor neurons.

Abstract: We have developed a series of mouse-mouse neural hybrid cell lines by fusing the aminopterin-sensitive neuroblastoma N18TG2 with motor neuron-enriched embryonic day 12-14 spinal cord cells. Of 30 neuroblastoma-spinal cord (NSC) hybrids displaying a multipolar neuron-like phenotype, 10 express choline acetyltransferase, and 4 induce twitching in cocultured mouse myotubules. NSC-19, NSC-34, and their subclones express additional properties expected of motor neurons, including generation of action potentials, expression of neurofilament triplet proteins, and acetylcholine synthesis, storage, and release. In addition, NSC-34 cells induce acetylcholine receptor clusters on cocultured myotubes, and undergo a vimentin-neurofilament switch with maturation in culture, similar to that occurring in neuronal development. NSC cell lines appear to model selected aspects of motor neuron development in an immortalized clonal system.

Managing I/S Design Teams: A Control Theories Perspective

Abstract: The control relationship between project managers and team members is a central aspect of the working of any Information System I/S design team. This paper combines research on managerial control and team-member control in order to explore a range of control behaviors that can affect the performance of an I/S design team. Measures are developed and validated for managerial control and team-member control from both an outcome and a process perspective. Results from a study of 41 actual I/S design teams indicate that high-performing teams exhibit high process control by managers and high outcome control by team members. The results also support the proposition that both managerial and team-member control coexists and that increases in the total level of control behavior is positively correlated with performance.

Couplings of watersheds and coastal waters: sources and consequences of nutrient enrichment in Waquoit Bay, Massachusetts

Abstract: Human activities on coastal watersheds provide the major sources of nutrients entering shallow coastal ecosystems. Nutrient loadings from watersheds are the most widespread factor that alters structure and function of receiving aquatic ecosystems. To investigate this coupling of land to marine systems, we are studying a series of subwatersheds of Waquoit Bay that differ in degree of urbanization and hence are exposed to widely different nutrient loading rates. The subwatersheds differ in the number of septic tanks and the relative acreage of forests. In the area of our study, groundwater is the major mechanism that transports nutrients to coastal waters. Although there is some attenuation of nutrient concentrations within the aquifer or at the sediment-water interface, in urbanized areas there are significant increases in the nutrient content of groundwater arriving at the shore’s edge. The groundwater seeps or flows through the sediment-water boundary, and sufficient groundwater-borne nutrients (nitrogen in particular) traverse the sediment-water boundary to cause significant changes in the aquatic ecosystem. These loading-dependent alterations include increased nutrients in water, greater primary production by phytoplankton, and increased macroaglal biomass and growth (mediated by a suite of physiological responses to abundance of nutrients). The increased macroalgal biomass dominates the bay ecosystem through second- or third-order effects such as alterations of nutrient status of water columns and increasing frequency of anoxic events. The increases in seaweeds have decreased the areas covered by eelgrass habitats. The change in habitat type, plus the increased frequency of anoxic events, change the composition of the benthic fauna. The data make evident the importance of bottom-up control in shallow coastal food webs. The coupling of land to sea by groundwater-borne nutrient transport is mediated by a complex series of steps; the cascade of processes make it unlikely to find a one-to-one relation between land use and conditions in the aquatic ecosystem. Study of the process and synthesis by appropriate models may provide a way to deal with the complexities of the coupling.

Communication in Coordination Games

Abstract: We present experimental evidence on nonbinding, preplay communication in bilateral coordination games. To evaluate the effect of "cheap talk," we consider two communication structures (one-way and two-way communication) and two types of coordination games (one with a cooperative strategy and a second in which one strategy is less "risky"). In games with a cooperative strategy, one-way communication increases play of the Pareto-dominant equilibrium relative to the no communication baseline; two-way communication does not always decrease the frequency of coordination failures. In the second type of game, two-way communication always leads to the Pareto-dominant Nash equilibrium, while one-way communication does not.

Free radicals mediate endothelial cell dysfunction caused by elevated glucose

Abstract: Impaired endothelium-dependent relaxation occurs in diabetic rabbit aorta and normal aorta exposed to elevated concentrations of glucose and is prevented by cyclooxygenase inhibitors. The role of free radicals in the endothelial cell impairment was examined with free radical scavengers and in aortas from rabbits fed with probucol (1% wt/wt, a lipid-soluble antioxidant). Rings of aorta suspended for measurement of isometric tension were incubated for 6 h in control (5.5 mM) or elevated (44 mM) glucose. Impairment of endothelium-dependent relaxation to acetylcholine caused by exposure to elevated glucose was prevented by superoxide dismutase, catalase, deferoxamine, or allopurinol and did not occur in aortas from probucol-fed rabbits. Similarly, impairment of acetylcholine relaxations in aortas from alloxan-induced diabetic rabbits was restored to normal by superoxide dismutase. Oxygen-derived free radicals generated by xanthine oxidase also caused impaired acetylcholine relaxations. Exposure of aortic segments to elevated glucose or to xanthine oxidase caused a significant increase in release of immunoreactive prostanoids. These data indicate that the endothelial cell dysfunction caused by elevated glucose is mediated by free radicals that are likely generated through the increased cyclooxygenase catalysis occurring in the endothelium. Treatment with antioxidants protects against impaired endothelium-dependent relaxations caused by elevated glucose.

Comparison of Amphotericin B with Fluconazole in the Treatment of Acute AIDS-Associated Cryptococcal Meningitis

Abstract: Background. Intravenous amphotericin B, with or without flucytosine, is usually standard therapy for cryptococcal meningitis in patients with the acquired immunodeficiency syndrome (AIDS). Fluconazole, an oral triazole agent, represents a promising new approach to the treatment of cryptococcal disease. Methods. In a randomized multicenter trial, we compared intravenous amphotericin B with oral fluconazole as primary therapy for AIDS-associated acute cryptococcal meningitis. Eligible patients, in all of whom the diagnosis had been confirmed by culture, were randomly assigned in a 2:1 ratio to receive either fluconazole (200 mg per day) or amphotericin B. Treatment was considered successful if the patient had had two consecutive negative cerebrospinal fluid cultures by the end of the 10-week treatment period. Results. Of the 194 eligible patients, 131 received fluconazole and 63 received amphotericin B (mean daily dose, 0.4 mg per kilogram of body weight in patients with successful treatment and 0....

Stock-Price Manipulation

Abstract: It is generally agreed that speculators can make profits from insider trading or from the release of false information. Both forms of stock-price manipulation have now been made illegal. In this article, the authors ask whether it is possible to make profits from a different kind of manipulation, in which an uninformed speculator simply buys and sells shares. They show that in a rational expectations framework, where all agents maximize expected utility, it is possible for an uninformed manipulator to make a profit, provided investors attach a positive probability to the manipulator being an informed trader. Article published by Oxford University Press on behalf of the Society for Financial Studies in its journal, The Review of Financial Studies.

Prevalence of dementia and probable senile dementia of the Alzheimer type in the Framingham Study.

Abstract: We determined the prevalence of dementia and probable senile dementia of the Alzheimer type (SDAT) for biennial Exam 17 of the Framingham cohort (1982/1983). The prevalence of dementia was 30.5/1,000 for men and 48.2/1,000 for women and increased with advancing age. Cases of probable SDAT constituted 55.6% of all dementia cases. THe prevalence of SDAT was 11.7/1,000 for men and 30.1/1,000 for women and also increased with advancing age. Prevalence of dementia and probable SDAT were greater for women than men. The female:male ratio of prevalence for cohort members 75 years of age and older was 1.8 for all cases of dementia and 2.8 for cases of probable SDAT.

Congenital bilateral absence of the vas deferens. A primarily genital form of cystic fibrosis

Abstract: Objective. —Almost all males with cystic fibrosis (CF) have absent vasa deferentia. It has been suggested that otherwise healthy males with congenital bilateral absence of the vas deferens (CBAVD), previously considered a distinct genetic entity, have an increased frequency of CF gene mutations. This study examined the genetic commonality of these two disorders. Design. —We typed six common CF gene mutations in 25 patients with CBAVD. Additional rare mutations were sought using single-stranded conformation polymorphisms and direct DNA sequencing. When rare mutations were found, they were sought in a large sample of both CF patients and obligate CF carriers to exclude them as polymorphisms. Setting. —All the patients presented to a male infertility clinic of a teaching hospital. Subjects. —Twenty-five unselected, unrelated azoospermic men with CBAVD, most of them of Northern European ancestry. Results. —Sixteen (64%) of the 25 men with CBAVD had at least one detectable CF mutation, 16 times the expected frequency (P Conclusions. —Some, if not all, otherwise healthy men with CBAVD reflect a newly recognized, primarily genital, phenotype of CF. Prior to sperm aspiration to remedy infertility, CF mutation analysis should be recommended for them and their partners, as well as for their relatives. (JAMA. 1992;267:1794-1797)

Genetic evidence for a novel familial Alzheimer's disease locus on chromosome 14

Abstract: Familial Alzheimer's disease (FAD) has been shown to be genetically heterogeneous, with a very small proportion of early onset pedigrees being associated with mutations in the amyloid precursor protein (APP) gene on chromosome 21, and some late onset pedigrees showing associations with markers on chromosome 19. We now provide evidence for a major early onset FAD locus on the long arm of chromosome 14 near the markers D14S43 and D14S53 (multipoint lod score z = 23.4) and suggest that the inheritance of FAD may be more complex than had initially been suspected.

Switching from differentiation to growth in hepatocytes: control by extracellular matrix.

Abstract: Studies were carried out to analyze how different extracellular matrix (ECM) molecules regulate hepatocyte growth and differentiation. Freshly isolated rat hepatocytes were cultured on non-adhesive plastic dishes that were pre-coated with defined densities of either laminin, fibronectin, type I collagen, or type IV collagen. Sparse cell plating densities were used to minimize cell-cell contact formation and all studies were carried out in chemically defined medium that contained a saturating amount of soluble growth factors. Dishes coated with a low ECM density (1 ng/cm2) supported hepatocyte attachment, but did not promote cell spreading or growth. Computerized image analysis confirmed that over 80% of cells remained free of contact with other cells under these conditions. Yet, these round cells maintained high levels of albumin gene expression as well as elevated secretion rates for multiple liver-specific proteins (albumin, transferrin, and fibrinogen), regardless of the type of ECM molecule used for cell attachment. When ECM coating densities were raised from 1 to 1,000 ng/cm2, cell spreading, expression of histone mRNA, DNA synthesis, and cell proliferation all increased in parallel. Activation of growth by high ECM densities was also accompanied by a concomitant down-regulation of differentiated functions and again, dishes coated with all four types of ECM molecules produced similar effects. Thus, the ability to switch hepatocytes from differentiation to growth (i.e., between different genetic programs) is not limited to a single ECM molecule, a distinct three dimensional ECM geometry, or due to alteration of cell-cell interactions. Rather, the regulatory signals conveyed by immobilized ECM molecules depend on the density at which they are presented and thus, on their ability to either prohibit or support cell spreading.

Fabricating budgets: A study of the production of management budgeting in the national health service

Abstract: This paper examines the processes by which a form of responsibility accounting system emerges in an organizational context. The paper utilizes recent approaches to the understanding of how science and technology is created (Latour, Science in Action, Harvard University Press, 1987) to investigate the processes by which a management budgeting initiative in the U.K. hospital system takes hold (or not) in specific hospitals. The approach is critical of the notion that accounting systems are well-defined technologies which are designed and then implemented (or face resistance). Instead, the study shows that management budgeting is fabricated, put together in a changing and fragile manner. Emerging accounting systems are not fixed technologies with well-defined purposes which reflect patterns of responsibility but changing constructions. Management budgeting systems are initiated with loose characteristics, purposes and uses. In the process of their design and implementation, new possibilities for decision making and definitions of responsibility emerge. Through this study of accounting in action, the paper explores the processes by which accounting and budgeting systems bring economic logic into hospital management. It is also relevant to debates about the role of budgeting and accounting in health care organizations in many countries.

An exonic mutation in the HuP2 paired domain gene causes Waardenburg's syndrome

Abstract: Here we report the identification and characterization of a gene defect causing Waardenburg's syndrome with hearing loss in a large Brazilian family. This demonstrates a mutation causing Waardenburg's syndrome as well as a mutation causing a form of congenital deafness. The mutation was found in the HuP2 gene, a member of the paired domain family of proteins that bind DNA and regulate gene expression. The mutation occurred in 100% of the cases with the disease in this family and was absent in a random sample of 50 unrelated control subjects. Identification of the Waardenburg's syndrome gene and future characterization of its gene product is likely to increase our understanding of the pathogenesis of this disorder and may allow prevention of deafness of this type.