762 research outputs found
A rare variant of the superficial ulnar artery, and its clinical implications: a case report
The superficial ulnar artery is a rare variation of the upper limb arterial system that arises from the brachial or axillary artery and runs superficial to the muscles arising from the medial epicondyle [1-3]. The incidence is about 0.7 to 7% [1,4,5]. In our routine dissections we found a superficial ulnar artery, which crossed the cubital fossa superficial to the bicipital aponeurosis making it highly vulnerable to intra-arterial injection. This is a rare variation that every medical and nursing staff member should know about
Effectiveness, cost-effectiveness and cost-benefit of a single annual professional intervention for the prevention of childhood dental caries in a remote rural Indigenous community
Background
The aim of the study is to reduce the high prevalence of tooth decay in children in a remote, rural Indigenous community in Australia, by application of a single annual dental preventive intervention. The study seeks to (1) assess the effectiveness of an annual oral health preventive intervention in slowing the incidence of dental caries in children in this community, (2) identify the mediating role of known risk factors for dental caries and (3) assess the cost-effectiveness and cost-benefit of the intervention.
Methods/design
The intervention is novel in that most dental preventive interventions require regular re-application, which is not possible in resource constrained communities. While tooth decay is preventable, self-care and healthy habits are lacking in these communities, placing more emphasis on health services to deliver an effective dental preventive intervention. Importantly, the study will assess cost-benefit and cost-effectiveness for broader implementation across similar communities in Australia and internationally.
Discussion
There is an urgent need to reduce the burden of dental decay in these communities, by implementing effective, cost-effective, feasible and sustainable dental prevention programs. Expected outcomes of this study include improved oral and general health of children within the community; an understanding of the costs associated with the intervention provided, and its comparison with the costs of allowing new lesions to develop, with associated treatment costs. Findings should be generalisable to similar communities around the world.
The research is registered with the Australian New Zealand Clinical Trials Registry (ANZCTR), registration number ACTRN12615000693527; date of registration: 3rd July 2015
Vertical integration in production and services: development in transaction cost economics
In this paper, we first establish the core, fundamental concepts of Williamson's TCE, examining the different governance structures or the institutional alternatives that TCE theory proposes. We go on to describe some critical considerations and theoretical proposals that correspond fundamentally to Williamson's heuristic model, the integration of incentives in organizational forms, idiosyncratic demand, and how the concept of transaction is conceived in general.Peris-Ortiz, M.; Bonet, F.; Rueda Armengot, C. (2011). Vertical integration in production and services: development in transaction cost economics. Service Business. 5(1):87-97. doi:10.1007/s11628-011-0103-0S879751Alchian A (1965) The basic of some recent advances in the theory of management of the firm. J Ind Econ 14:30–41Alchian A (1969) Corporate management and property rights. In: Manne GH (ed) Economic Policy and Regulation of Corporate Securities. American Enterprise Institute of Public Policy Research, Washington, DCAlchian A, Demsetz H (1972) Production, information cost, and economic organization. Am Econ Rev 62:777–795Arrow KJ (1959) Toward a theory of price adjustment. In: Abramovitz M et al (eds) The allocation of resources. Stanford University Press, Stanford, CA, pp 41–51Arrow KJ (1973) Information and economic behaviour. Federation of Swedish Industries, StockholmArrow KJ (1974) The limits of organizations. W. W. Norton, New YorkBain J (1956) Barriers to new competition. Harvard University Press, Cambridge, MABain J (1958) Industrial organization, 2nd edn. John Wiley & Sons, New YorkBarnard CI (1938) The functions of the executive. Cambridge University Press, Cambridge, MAChandler AC Jr. (1962) Strategy and structure. MIT Press, Cambridge, MAChandler AC Jr. (1977) The visible hand. Harvard University Press, Cambridge, MACoase RH (1937) The nature of the firm. Economica 4:386–405Coase RH (1972) Industrial organization: a proposal for research. In: Victor RF (ed) Policy issues and research opportunities in industrial organization. National Bureau of Economic Research, New York, pp 59–73Coase RH (1991) The institutional structure of production. Prize Lecture to the Memory of Alfred Nobel, December 9, 1991, http://www.nobel.se/economics/laureates/1991/coase-lecture.htmlCyert RM, March JG (1963) A behavioural theory of the firm. Prentice-Hall, Englewood Cliffs, NJDemsetz H (1967) Toward a theory of property rights. Am Econ Rev 57:347–359Demsetz H (1991) The theory of the firm revisited. In: Williamson O, Winter S (eds) The nature of the firm: origins, evolution, and development. Oxford University Press, New York, pp 159–178Galbraith JR (1993) The value-adding corporation: matching structure with strategy. In: Galbraith JR, Lawler III EE and Associates (eds) Organizing for the future. Jossey-Bass Publishers, San Francisco, pp 15–42Li J-M, Yang J-S, Wu HH (2009) Analysis of competence differences among frontline employees from various service typologies. Serv Ind J 29(12):1763–1778Ouchi WG (1979) A conceptual framework for the design of organizational control mechanism. Manag Sci 25(9):833–848Ouchi WG (1980) Markets, bureaucracies, and clans. Admin Sci Q 25:120–142Palmer M, Owens M, De Kervenoael R (2010) Paths of the least resistance: understanding how motives form in international retail joint venturing. Serv Ind J 30(6):965–989Robinson J (1933) The economics of imperfect competition. Macmillan, LondonSafón V (2009) The moderating effect of the technological level of industry on the relationship between innovation and corporate reputation. Int Entrep Manag J 5(4):515–526Simon HA (1947) Administrative behavior. Macmillan, New YorkSimon HA (1962) The architecture of complexity. Proc Am Philos Soc 106:467–482Simon HA (1973) Applying information technology to organization design. Public Admin Rev 33:268–278Un CA, Romero-Martínez AM, Montoro-Sánchez A (2009) Determinants of R&D collaboration of service firms. Serv Bus 3:373–394Warren L, Patton D, Bream D (2009) Knowledge acquisition processes during the incubation of new high technology firms. Int Entrep Manag J 5(4):481–495Williamson OE (1975) Markets and hierarchies: analysis and antitrust implication. Free Press, New YorkWilliamson OE (1979) Transaction-cost economics: the governance of contractual relations. J Law Econ 22:3–61Williamson OE (1981) The modern corporation: origins, evolution, attributes. J Econ Lit 19:1537–1568Williamson OE (1985) The economic institutions of capitalism. Free Press, New YorkWilliamson OE (1991) Comparative economic organization: the analysis of discrete structural alternatives. Admin Sci Q 36:269–296Williamson OE (1993) Calculativeness trust and economic organization. J Law Econ 36:453–486Williamson OE (1996) The mechanisms of governance. Oxford University Press, New York, pp 250–278Williamson OE (1999) Strategy research: governance and competence perspectives. Strateg Manag J 20:1087–1108Williamson OE (2000) The new institutional economics: taking stock, looking ahead. J Econ Lit 38:595–613Williamson OE (2003) Examining economic organization through the lens of contract. Ind Corp Change 12(4):917–938Williamson OE (2005) Transaction cost economics and business administration. Scand J Manag 21:19–40Williamson OE (2008) Outsourcing: transaction cost economics and supply chain management. J Supply Chain Manag 44(2):5–16Williamson OE, Bhargava WH (1986) Assessing and classifying the internal structure and control apparatus of the modern corporation. In: Williamson OE (ed) Economic organization. Firms, markets and policy control. Wheatsheaf Books, Great Britain, Brighton, pp 54–8
Model based analysis of real-time PCR data from DNA binding dye protocols
BACKGROUND: Reverse transcription followed by real-time PCR is widely used for quantification of specific mRNA, and with the use of double-stranded DNA binding dyes it is becoming a standard for microarray data validation. Despite the kinetic information generated by real-time PCR, most popular analysis methods assume constant amplification efficiency among samples, introducing strong biases when amplification efficiencies are not the same. RESULTS: We present here a new mathematical model based on the classic exponential description of the PCR, but modeling amplification efficiency as a sigmoidal function of the product yield. The model was validated with experimental results and used for the development of a new method for real-time PCR data analysis. This model based method for real-time PCR data analysis showed the best accuracy and precision compared with previous methods when used for quantification of in-silico generated and experimental real-time PCR results. Moreover, the method is suitable for the analyses of samples with similar or dissimilar amplification efficiency. CONCLUSION: The presented method showed the best accuracy and precision. Moreover, it does not depend on calibration curves, making it ideal for fully automated high-throughput applications
Perspectives on the Trypanosoma cruzi-host cell receptor interaction
Chagas disease is caused by the parasite Trypanosoma cruzi. The critical initial event is the interaction of the trypomastigote form of the parasite with host receptors. This review highlights recent observations concerning these interactions. Some of the key receptors considered are those for thromboxane, bradykinin, and for the nerve growth factor TrKA. Other important receptors such as galectin-3, thrombospondin, and laminin are also discussed. Investigation into the molecular biology and cell biology of host receptors for T. cruzi may provide novel therapeutic targets
Inequities in maternal postnatal visits among public and private patients: 2004 Pelotas cohort study
<p>Abstract</p> <p>Background</p> <p>The postnatal period is the ideal time to deliver interventions to improve the health of both the newborn and the mother. However, postnatal care shows low-level coverage in a large number of countries. The objectives of this study were to: 1) investigate inequities in maternal postnatal visits, 2) examine differences in postnatal care coverage between public and private providers and 3) explore the relationship between the absence of maternal postnatal visits and exclusive breastfeeding, use of contraceptive methods and maternal smoking three months after birth.</p> <p>Methods</p> <p>In the calendar year of 2004 a birth cohort study was started in the city of Pelotas, Brazil. Mothers were interviewed soon after delivery and at three months after birth. The absence of postnatal visits was defined as having no consultations between the time of hospital discharge and the third month post-partum. Logistic regression analysis was used to estimate the association between absence of postnatal visits and type of insurance scheme adjusting for potential confounding factors.</p> <p>Results</p> <p>Poorer women, black/mixed, those with lower level of education, single mothers, adolescents, multiparae, smokers, women who delivered vaginally and those who were not assisted by a physician were less likely to attend postnatal care. Postnatal visits were also less frequent among women who relied in the public sector than among private patients (72.4% vs 96% among public and private patients, respectively, <it>x</it><sup>2 </sup>p < 0.001) and this difference was not explained either by maternal characteristics or by health care utilization patterns. Women who attended postnatal visits were more likely to exclusively breastfeed their infants, to use contraceptive methods and to be non-smokers three months after birth.</p> <p>Conclusion</p> <p>Postpartum care is available for every woman free of charge in the Brazilian Publicly-funded health care system. However, low levels of postpartum care were seen in the study (77%). Efforts should be made to increase the percentage of women receiving postpartum care, particularly those in socially disadvantaged groups. This could include locally-adapted health education interventions that address women's beliefs and attitudes towards postpartum care. There is a need to monitor postpartum care and collected data should be used to guide policies for health care systems.</p
Pharmacokinetics of Teriparatide (rhPTH[1–34]) and Calcium Pharmacodynamics in Postmenopausal Women with Osteoporosis
Teriparatide (rhPTH[1–34]) affects calcium metabolism in a pattern consistent with the known actions of endogenous parathyroid hormone (PTH). This report describes the pharmacokinetics and resulting serum calcium response to teriparatide in postmenopausal women with osteoporosis. Pharmacokinetic samples for this analysis were obtained from 360 women who participated in the Fracture Prevention Trial. Postmenopausal women with osteoporosis received daily subcutaneous injections of either teriparatide 20 μg (4.86 μmol) or placebo, median 21 months’ treatment. Serum teriparatide and calcium concentrations were measured throughout the study. An indirect-response model was developed to describe the pharmacokinetic–pharmacodynamic relationship between teriparatide concentrations and serum calcium response. The pharmacokinetics of teriparatide were characterized by rapid absorption (maximum concentration achieved within 30 min) and rapid elimination (half-life of 1 h), resulting in a total duration of exposure to the peptide of approximately 4 h. Teriparatide transiently increased serum calcium, with the maximum effect observed at approximately 4.25 h (median increase 0.4 mg/dl [0.1 mmol/l]). Calcium concentrations returned to predose levels by 16–24 h after each dose. Persistent hypercalcemia was not observed; one teriparatide 20 μg-treated patient had a predose serum calcium value above the normal range but <11.0 mg/dl (2.75 mmol/l). Following once-daily subcutaneous administration, teriparatide produces a modest but transient increase in serum calcium, consistent with the known effects of endogenous PTH on mineral metabolism. The excursion in serum calcium is brief, due to the short length of time that teriparatide concentrations are elevated
Context-sensitive autoassociative memories as expert systems in medical diagnosis
BACKGROUND: The complexity of our contemporary medical practice has impelled the development of different decision-support aids based on artificial intelligence and neural networks. Distributed associative memories are neural network models that fit perfectly well to the vision of cognition emerging from current neurosciences. METHODS: We present the context-dependent autoassociative memory model. The sets of diseases and symptoms are mapped onto a pair of basis of orthogonal vectors. A matrix memory stores the associations between the signs and symptoms, and their corresponding diseases. A minimal numerical example is presented to show how to instruct the memory and how the system works. In order to provide a quick appreciation of the validity of the model and its potential clinical relevance we implemented an application with real data. A memory was trained with published data of neonates with suspected late-onset sepsis in a neonatal intensive care unit (NICU). A set of personal clinical observations was used as a test set to evaluate the capacity of the model to discriminate between septic and non-septic neonates on the basis of clinical and laboratory findings. RESULTS: We show here that matrix memory models with associations modulated by context can perform automatic medical diagnosis. The sequential availability of new information over time makes the system progress in a narrowing process that reduces the range of diagnostic possibilities. At each step the system provides a probabilistic map of the different possible diagnoses to that moment. The system can incorporate the clinical experience, building in that way a representative database of historical data that captures geo-demographical differences between patient populations. The trained model succeeds in diagnosing late-onset sepsis within the test set of infants in the NICU: sensitivity 100%; specificity 80%; percentage of true positives 91%; percentage of true negatives 100%; accuracy (true positives plus true negatives over the totality of patients) 93,3%; and Cohen's kappa index 0,84. CONCLUSION: Context-dependent associative memories can operate as medical expert systems. The model is presented in a simple and tutorial way to encourage straightforward implementations by medical groups. An application with real data, presented as a primary evaluation of the validity and potentiality of the model in medical diagnosis, shows that the model is a highly promising alternative in the development of accuracy diagnostic tools
Reducing neonatal mortality associated with preterm birth: gaps in knowledge of the impact of antenatal corticosteroids on preterm birth outcomes in low-middle income countries
The Effect of Polyhydramnios on Cervical Length in Twins: A Controlled Intervention Study in Complicated Monochorionic Pregnancies
Objective: To test the hypothesis that cervical shortening in polyhydramnios reflects the degree of excess amniotic fluid, and increases with normalisation of amniotic fluid volume. Study Design: Prospective cohort study of 40 women with monochorionic twins undergoing interventional procedures between 16-26 weeks. Cervical length was assessed via transvaginal sonography pre-procedure, 1 and 24 hours postprocedure, and results compared between amnioreduction and control procedures. Amniotic fluid index (AFI) was measured pre- and post-procedure. Results: Pre-procedural cervical length correlated with AFI (linear fit = 5.07 -0.04x, R2 = 0.17, P = 0.03) in patients with polyhydramnios (n = 28). Drainage of 2000ml fluid (range 700-3500ml), reduced AFI from 42cm to 21cm (P>0.001). Their pre-procedural cervical length did not change at one (mean Δ:-0.1cm, 95%CI, -0.4 to 0.2) or 24 hours (0.2cm, -0.1 to 0.6) after amnioreduction. There was no change in cervical length at control procedures. Conclusion: Cervical shortening in twins with polyhydramnios does not appear to be an acute process; cervical length can be measured before or after therapeutic procedures. © 2008 Engineer et al
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