Books on the topic 'Variance reduction'
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1
Mahmood, M. A. Variance reduction techniques in the simulation of queueingproblems. Manchester: UMIST, 1986.
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2
Lewis, Peter A. W. Variance reduction for quantile estimates in simulations via nonlinear controls. Monterey, Calif: Naval Postgraduate School, 1990.
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3
Lessi, O. Problems of variance reduction in the simulation of random variables. Luxembourg: Commission of the European Communities, 1987.
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4
Trietsch, Dan. A proposal to apply Taguchi-Inspired Methods to the reduction of machining variance. Monterey, Calif: Naval Postgraduate School, 1992.
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Ressler, Richard L. An investigation of nonlinear controls and regression-adjusted estimators for variance reduction in computer simulation. Monterey, Calif: Naval Postgraduate School, 1991.
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Mackenzie, Anne I. Three averaging techniques for reduction of antenna temperature variance measured by a Dicke mode, C-band radiometer. Hampton, Va: National Aeronautics and Space Administration, Langley Research Center, 2000.
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7
Smoot, Melissa C. An analysis of noise reduction in variable reluctance motors using pulse position randomization. Springfield, Va: Available from National Technical Information Service, 1994.
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Brausch, John F. Simulated flight acoustic investigtion of treated ejector effectiveness on advanced mechanical suppressors for high velocity jet noise reduction. Cleveland, Ohio: Lewis Research Center, 1986.
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9
Institute for Computer Applications in Science and Engineering., ed. Practical aspects of variable reduction formulations and reduced basis algorithms in multidisciplinary design optimization. Hampton, VA: Institute for Computer Applications in Science and Engineering, NASA Langley Research Center, 1995.
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10
Replicative Use of an External Model in Simulation Variance Reduction. Storming Media, 1996.
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11
Bartholomew, David. Bias and variance reduction in a post-stratified two-stage design. Joint Centre for Survey Methods, 1990.
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12
Lessi, O. Variance Reduction Techniques in the Simulation of Markov Processes (Nuclear Science and Technology). European Communities / Union (EUR-OP/OOPEC/OPOCE), 1987.
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13
Smith, Curtis. Pilot study on the applicability of variance reduction techniques to the simulation of a stochastic combat model. 1987.
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14
National Aeronautics and Space Administration (NASA) Staff. Three Averaging Techniques for Reduction of Antenna Temperature Variance Measured by a Dicke Mode, C-Band Radiometer. Independently Published, 2018.
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15
Methods for statistical data analysis of multivariate observations. 2nd ed. New York, NY: Wiley, 1997.
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Methods for Statistical Data Analysis of Multivariate Observations. Wiley & Sons Canada, Limited, John, 2011.
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Methods for Statistical Data Analysis of Multivariate Observations. Wiley & Sons, Incorporated, John, 2011.
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18
Gnanadesikan, R. Methods for Statistical Data Analysis of Multivariate Observations. Wiley & Sons, Incorporated, John, 2011.
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19
Wright, Richard. The role of policy in preventing sexual violence. Edited by Teela Sanders. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780190213633.013.17.
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This essay focuses on the role of law and policy in sexual assault and offending. Comparing and contrasting U.S., Canadian, and European policy approaches, the review examines how various governments have prioritized their legal approaches to sexual offending prevention and response. These responses have included broad-based conviction-focused schemes, narrowly focused laws centered on high-risk repeat offenders, and prioritization with stranger-based assault. There has been great variance in terms of the emphasis placed on treatment and public notification. The essay analyses how these nations have learned from each other and how their sex offending policies have evolved, if and how they reflect the science of sexual offending and risk, and which demonstrate the most promise for sexual assault reduction with the fewest unintended consequences.
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Akinsel, Serdar. Reduction in bandwidth by using variable length codes. 1985.
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21
Collier, K. Steven. Deployment planning: A linear programming model with variable reduction. 1987.
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22
National Aeronautics and Space Administration (NASA) Staff. Vibration Reduction of Helicopter Blade Using Variable Dampers: A Feasibility Study. Independently Published, 2018.
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23
Reduction in mill air compressor power requirements through installation of a variable speed control. Bonneville Power Administration., 1988.
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24
Langer, Thomas, and Pietro Caironi. Pathophysiology and therapeutic strategy of respiratory alkalosis. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199600830.003.0114.
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Respiratory alkalosis is a condition characterized by low partial pressure of carbon dioxide and an associated elevation in arterial pH caused by an imbalance between CO2 production and removal, in favour of the latter. Conditions that cause increased alveolar ventilation, without having a reduction in pH as input stimulus, will cause hypocapnia associated with a variable degree of alkalosis. The major effect of hypocapnia is the increase in pH (alkalosis) and the consequent shift of electrolytes that occurs in relation to it. As a general law, in plasma, anions will increase, while cations will decrease. The acute reduction in ionized calcium, due to the change in extracellular pH, may cause neuromuscular symptoms ranging from paraesthesias, to tetany and seizures. The effect on urine is an increase in urinary strong ion difference/urinary anion gap and a consequent increase in urinary pH. Finally, acute hypocapnic alkalosis causes a constriction of cerebral arteries that can lead to a reduction of cerebral blood flow. The clinical approach to respiratory alkalosis is usually directed toward the diagnosis and treatment of the underlying clinical disorder.
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Stafstrom, Carl E. Alternative Therapies for Epilepsy. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199937837.003.0046.
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Up to one third of patients with epilepsy suffer from seizures that are refractory to medications. For these patients, many of whom are not surgical candidates, dietary therapies provide a promising alternative. The best known dietary therapy is the ketogenic diet, which was developed in the 1920s; newer variants of the ketogenic diet, such as the medium-chain triglyceride diet, modified Atkins diet, and low glycemic index treatment, afford excellent seizure control with fewer dietary restrictions. Together, dietary approaches offer drug-resistant patients hope for seizure reduction and an improved quality of life.
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Commercial Vehicles 2021. VDI Verlag, 2021. http://dx.doi.org/10.51202/9783181023808.
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Contents Ways to achieve Zero Emission ZF E-Mobility products and software for commercial vehicles ..... 1 Thermoelectric generators for heavy-duty vehicles as an economical waste heat recovery system ..... 17 Hybridization of heavy duty trucks – Market analysis and technology for high voltage as well as low voltage solutions ..... 33 Development processes and methods Lightweight construction and cost reduction – a lean, agile MSCDPS® product development process ..... 43 eDrive & Fuel Cell powertrain systems engineering for commercial vehicles ..... 55 Fatigue development of a 10x10 commercial vehicle frame using dynamic and/or strength simulation, virtual iteration and component testing together with measurement data acquisition ..... 73 Data-driven selection of vehicle variants for the E/E integration test – Increasing variants and complex technology versus test coverage ..... 81 Hydrogen propulsion High performance and efficiency hydrogen engine using westport fuel systems’ Commercially available HPDI fuel system ..... 97 E/E architecture and operating strategy for fuel-cell trucks – Challenges...
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Hollak, Carla E. M. Gaucher Disease. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199972135.003.0047.
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Gaucher disease is frequently diagnosed in adulthood and may manifest at any age. Chronic neuronopathic forms are rarely seen but may come to the attention of the adult physician. Nonneuronopathic or type 1 disease is extremely variable. Main symptoms are cytopenia, hepatosplenomegaly and bone disease. The majority of patients diagnosed in adulthood present with thrombocytopenia and splenomegaly. In moderate to severe disease, treatment with intravenous enzyme replacement is highly effective. Substrate reduction therapy with miglustat or eliglustat is an oral alternative for some. Awareness of a number of severe complications and associated conditions, including irreversible bone disease, rare cancers and Parkinson's disease, is of importance.
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Ewald, Paul W. Evolutionary control of infectious disease in low-income countries. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198789833.003.0009.
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An evolutionary suggests that health interventions can reduce not only the frequency of infectious disease but also the harmfulness of the causal organisms. Interventions that may accomplish this dual goal include hygienic investments such as vector proofing of housing, provisioning of safe water supplies, infrastructure that blocks transmission of durable propagules, the prevention of attendant-borne transmission in hospitals and reductions in the potential for sexual transmission. Vaccines can also reduce the frequency of infection and the harmfulness of the target organisms if they are designed to inhibit selectively the harmful variants in the target population. These approaches should help suppress the evolution of antimicrobial resistance because benign variants causing mild or asymptomatic infections will be less exposed to antimicrobial treatment, reducing the strength of selection for antimicrobial resistance. The interventions should improve health at low cost, which would be especially important for low-income populations.
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Jordan, Nerissa. Neurocutaneous syndromes. Edited by Patrick Davey and David Sprigings. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780199568741.003.0224.
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The neurocutaneous syndromes comprise a diverse group of rare genetic disorders with both neurological and cutaneous manifestations. Each syndrome has a distinct phenotype. Symptoms are variable and depend on the syndrome. Neurocutaneous syndromes often present in childhood or adolescence; for example, tuberous sclerosis typically presents in early childhood. The age range of presentation is broad, depending on the specific condition and severity of expression. The majority are autosomally inherited conditions. De novo mutations can occur. Most neurocutaneous syndromes do not have a specific treatment, and management is predominantly supportive and aimed at symptom reduction and appropriate monitoring. This chapter discusses neurocutaneous syndromes, including their symptoms, demographics, etiologies, natural history, complications, diagnosis, prognosis, and treatment.
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Ferraty, Frédéric, and Philippe Vieu. A Unifying Classification for Functional Regression Modeling. Edited by Frédéric Ferraty and Yves Romain. Oxford University Press, 2018. http://dx.doi.org/10.1093/oxfordhb/9780199568444.013.1.
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This article presents a unifying classification for functional regression modeling, and more specifically for modeling the link between two variables X and Y, when the explanatory variable (X) is of a functional nature. It first provides a background on the proposed classification of regression models, focusing on the regression problem and defining parametric, semiparametric, and nonparametric models, and explains how semiparametric modeling can be interpreted in terms of dimension reduction. It then gives four examples of functional regression models, namely: functional linear regression model, additive functional regression model, smooth nonparametric functional model, and single functional index model. It also considers a number of new models, directly adapted to functional variables from the existing standard multivariate literature.
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Gray, Hazel. Turbulence and Order in Economic Development. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198714644.001.0001.
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The terms of debate on the role of institutions in economic development are changing. Stable market institutions, in particular secure private property rights and democratically accountable governments that uphold the rule of law, are widely seen to be a prerequisite for economic transformation in low-income countries. Yet over the last thirty years, economic growth and structural transformation has surged forward in a range of countries where market and state institutions have differed from these ideals, as well as from each other. This book studies the role of the state in economic transformation in two such countries, Tanzania and Vietnam. These were two of the poorest countries in the world in the early 1980s but, over the last thirty years, both have experienced significant changes in the pace and character of economic development. While both countries experienced faster rates of GDP growth, their paths of economic transformation were very different. Vietnam experienced rapid manufacturing growth and poverty reduction while Tanzania’s path of economic change was characterized by the rise of mining and a much slower pace of poverty reduction. Employing a political settlements approach, this book argues that their paths of economic transformation were mediated by the lasting influence of differences in the institutions and distributions of power that had been forged during the socialist period. The comparison generates new insights into the variable relationship between political order and economic outcomes.
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Suls, Jerry, and Karina W. Davidson. Depression and Cardiovascular Diseases. Edited by C. Steven Richards and Michael W. O'Hara. Oxford University Press, 2013. http://dx.doi.org/10.1093/oxfordhb/9780199797004.013.006.
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This chapter provides a selective review of empirical studies concerning the relationship between depression and depressive symptomatology as risk factors for cardiovascular diseases. Depression appears to confer a twofold risk for both cardiac disease incidence and cardiac disease progression. Several factors appear to contribute to this risk, including the effects of depression on immune activity, endothelial function, SNS and HPA activity, and medical adherence. However, it remains unclear whether depression is only marking risk of some unmeasured third variable responsible for increased heart disease. Although antidepressant medication and cognitive behavioral therapy produce some reduction of depression in cardiac patients, there are no definitive clinical trial data showing medical or behavioral treatment reduce cardiac deaths. Only large-scale randomized clinical trials can fill this gap. The chapter concludes with a series of critical questions requiring resolution to decide what treatment would work most effectively for the cardiac patient with depression.
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Raghunathan, Karthik, and Andrew Shaw. Crystalloids in critical illness. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199600830.003.0057.
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‘Crystalloid’ refers to solutions of crystalline substances that can pass through a semipermeable membrane and are distributed widely in body fluid compartments. The conventional Starling model predicts transvascular exchange based on the net balance of opposing hydrostatic and oncotic forces. Based on this model, colloids might be considered superior resuscitative fluids. However, observations of fluid behaviour during critical illness are not consistent with such predictions. Large randomized controlled studies have consistently found that colloids offer no survival advantage relative to crystalloids in critically-ill patients. A revised Starling model describes a central role for the endothelial glycocalyx in determining fluid disposition. This model supports crystalloid utilization in most critical care settings where the endothelial surface layer is disrupted and lower capillary pressures (hypovolaemia) make volume expansion with crystalloids effective, since transvascular filtration decreases, intravascular retention increases and clearance is significantly reduced. There are important negative consequences of both inadequate and excessive crystalloid resuscitation. Precise dosing may be titrated based on functional measures of preload responsiveness like pulse pressure variation or responses to manoeuvres such as passive leg raising. Crystalloids have variable electrolyte concentrations, volumes of distribution, and, consequently variable effects on plasma pH. Choosing balanced crystalloid solutions for resuscitation may be potentially advantageous versus ‘normal’ (isotonic, 0.9%) saline solutions. When used as the primary fluid for resuscitation, saline solutions may have adverse effects in critically-ill patients secondary to a reduction in the strong ion difference and hyperchloraemic, metabolic acidosis. Significant negative effects on immune and renal function may result as well.
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Perez-Ruiz, Fernando, Irati Urionagüena, and Sandra P. Chinchilla. Long-term management of gout. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199668847.003.0046.
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Long-term management of gout comprises several aspects. Although in the short term, prophylaxis and treatment of acute episodes of inflammation are of great importance, the milestone for the long-term management of gout is targeted, sustained, and long-term control of hyperuricaemia. Treating to target subsaturating serum urate (SUA) levels, which may be initially dependent on the severity of the disease in the individual patient, is associated with a progressive reduction to no episodes of acute inflammation, regression and disappearance of subcutaneous and articular monosodium urate deposits and associated chronic inflammation, and improvement in patient-reported, health-related quality of life. Early and effective urate-lowering treatment to target levels will also prevent the development of structural damage. Urate-lowering treatment includes any measure intending to reduce SUA levels to target: lifestyle changes, modifications of concomitant medications favouring hyperuricaemia, and urate-lowering medications (ULMs). Availability of ULMs is variable worldwide, and prescription should be judicious, according to approved labels, and always considering associated health conditions and concomitant medications. Effectiveness and safety should be periodically monitored. Long-term treatment of gout still remains suboptimal in the twenty-first century. As practising clinicians, we cannot afford to neglect a ‘curable disease’.
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Gibson, Mark, and Juana Gil, eds. Romance Phonetics and Phonology. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198739401.001.0001.
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The research in this volume addresses several recurring topics in Romance Phonetics and Phonology with a special focus on the segment, syllable, word, and phrase levels of analysis. The original research presented in this volume ranges from the low-level mechanical processes involved in speech production and perception to high-level representation and computation. The interaction between these two dimensions of speech and their effects on first- and second-language acquisition are methodically treated in later chapters. Individual chapters address rhotics in various languages (Spanish, Italian, and Brazilian Portuguese), both taps and trills, singleton and geminate; vowel nasalization and associated changes; sibilants and fricatives, the ways in which vowels are affected by their position; there are explorations of diphthongs and consonant clusters in Romanian; variant consonant production in three Catalan dialects; voice quality discrimination in Italian by native speakers of Spanish; mutual language perception by French and Spanish native speakers of each other’s language; poetry recitation (vis-à-vis rhotics in particular); French prosodic structure; glide modifications and pre-voicing in onsets in Spanish and Catalan; vowel reduction in Galician; and detailed investigations of bilinguals’ language acquisition. A number of experimental methods are employed to address the topics under study including both acoustic and articulatory data; electropalatography (EPG), ultrasound, electromagnetic articulography (EMA).
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Goligorsky, Michael S., Julien Maizel, Radovan Vasko, May M. Rabadi, and Brian B. Ratliff. Pathophysiology of acute kidney injury. Edited by Norbert Lameire. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199592548.003.0221.
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In the intricate maze of proposed mechanisms, modifiers, modulators, and sensitizers for acute kidney injury (AKI) and diverse causes inducing it, this chapter focuses on several common and undisputable strands which do exist.Structurally, the loss of the brush border, desquamation of tubular epithelial cells, and obstruction of the tubular lumen are commonly observed, albeit to various degrees. These morphologic hallmarks of AKI are accompanied by functional defects, most consistently reflected in the decreased glomerular filtration rate and variable degree of reduction in renal blood flow, accompanied by changes in the microcirculation. Although all renal resident cells participate in AKI, the brunt falls on the epithelial and endothelial cells, the fact that underlies the development of tubular epithelial and vascular compromise.This chapter further summarizes the involvement of several cell organelles in AKI: mitochondrial involvement in perturbed energy metabolism, lysosomal involvement in degradation of misfolded proteins and damaged organelles, and peroxisomal involvement in the regulation of oxidative stress and metabolism, all of which become defective. Common molecular pathways are engaged in cellular stress response and their roles in cell death or survival. The diverse families of nephrotoxic medications and the respective mechanisms they induce AKI are discussed. The mechanisms of action of some nephrotoxins are analysed, and also of the preventive therapies of ischaemic or pharmacologic pre-conditioning.An emerging concept of the systemic inflammatory response triggered by AKI, which can potentially aggravate the local injury or tend to facilitate the repair of the kidney, is presented. Rational therapeutic strategies should be based on these well-established pathophysiological hallmarks of AKI.
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Gleń-Karolczyk, Katarzyna. Zabiegi ochronne kształtujące plonowanie zdrowotność oraz różnorodność mikroorganizmów związanych z czernieniem pierścieniowym korzeni chrzanu (Atmoracia rusticana Gaertn.). Publishing House of the University of Agriculture in Krakow, 2019. http://dx.doi.org/10.15576/978-83-66602-39-7.
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Horseradish roots, due to the content of many valuable nutrients and substances with healing and pro-health properties, are used more and more in medicine, food industry and cosmetics. In Poland, the cultivation of horseradish is considered minor crops. In addition, its limited size causes horseradish producers to encounter a number of unresolved agrotechnical problems. Infectious diseases developing on the leaves and roots during the long growing season reduce the size and quality of root crops. The small range of protection products intended for use in the cultivation of horseradish generates further serious environmental problems (immunization of pathogens, low effectiveness, deterioration of the quality of raw materials intended for industry, destruction of beneficial organisms and biodiversity). In order to meet the problems encountered by horseradish producers and taking into account the lack of data on: yielding, occurrence of infectious diseases and the possibility of combating them with methods alternative to chemical ones in the years 2012–2015, rigorous experiments have been carried out. The paper compares the impact of chemical protection and its reduced variants with biological protection on: total yield of horseradish roots and its structure. The intensification of infectious diseases on horseradish leaves and roots was analyzed extensively. Correlations were examined between individual disease entities and total yield and separated root fractions. A very important and innovative part of the work was to learn about the microbial communities involved in the epidemiology of Verticillium wilt of horseradish roots. The effect was examined of treatment of horseradish cuttings with a biological preparation (Pythium oligandrum), a chemical preparation (thiophanate-methyl), and the Kelpak SL biostimulator (auxins and cytokinins from the Ecklonia maxima algae) on the quantitative and qualitative changes occurring in the communities of these microorganisms. The affiliation of species to groups of frequencies was arranged hierarchically, and the biodiversity of these communities was expressed by the following indicators: Simpson index, Shannon–Wiener index, Shannon evenness index and species richness index. Correlations were assessed between the number of communities, indicators of their biodiversity and intensification of Verticillium wilt of horseradish roots. It was shown that the total yield of horseradish roots was on average 126 dt · ha–1. Within its structure, the main root was 56%, whereas the fraction of lateral roots (cuttings) with a length of more than 20 cm accounted for 26%, and those shorter than 20 cm for 12%, with unprofitable yield (waste) of 6%. In the years with higher humidity, the total root yield was higher than in the dry seasons by around 51 dt · ha–1 on average. On the other hand, the applied protection treatments significantly increased the total yield of horseradish roots from 4,6 to 45,3 dt · ha–1 and the share of fractions of more than 30 cm therein. Higher yielding effects were obtained in variants with a reduced amount of foliar application of fungicides at the expense of introducing biopreparations and biostimulators (R1, R2, R3) and in chemical protection (Ch) than in biological protection (B1, B2) and with the limitation of treatments only to the treatment of cuttings. The largest increments can be expected after treating the seedlings with Topsin M 500 SC and spraying the leaves: 1 × Amistar Opti 480 SC, 1 × Polyversum WP, 1 × Timorex Gold 24 EC and three times with biostimulators (2 × Kelpak SL + 1 × Tytanit). In the perspective of the increasing water deficit, among the biological protection methods, the (B2) variant with the treatment of seedlings with auxins and cytokinins contained in the E. maxima algae extract is more recommended than (B1) involving the use of P. oligandrum spores. White rust was the biggest threat on horseradish plantations, whereas the following occurred to a lesser extent: Phoma leaf spot, Cylindrosporium disease, Alternaria black spot and Verticillium wilt. In turn, on the surface of the roots it was dry root rot and inside – Verticillium wilt of horseradish roots. The best health of the leaves and roots was ensured by full chemical protection (cuttings treatment + 6 foliar applications). A similar effect of protection against Albugo candida and Pyrenopeziza brassicae was achieved in the case of reduced chemical protection to one foliar treatment with synthetic fungicide, two treatments with biological preparations (Polyversum WP and Timorex Gold 24 EC) and three treatments with biostimulators (2 × Kelpak SL, 1 × Tytanit). On the other hand, the level of limitation of root diseases comparable with chemical protection was ensured by its reduced variants R3 and R2, and in the case of dry root rot, also both variants of biological protection. In the dry years, over 60% of the roots showed symptoms of Verticillium wilt, and its main culprits are Verticillium dahliae (37.4%), Globisporangium irregulare (7.2%), Ilyonectria destructans (7.0%), Fusarium acuminatum (6.7%), Rhizoctonia solani (6.0%), Epicoccum nigrum (5.4%), Alternaria brassicae (5.17%). The Kelpak SL biostimulator and the Polyversum WP biological preparation contributed to the increased biodiversity of microbial communities associated with Verticillium wilt of horseradish roots. In turn, along with its increase, the intensification of the disease symptoms decreased. There was a significant correlation between the richness of species in the communities of microbial isolates and the intensification of Verticillium wilt of horseradish roots. Each additional species of microorganism contributed to the reduction of disease intensification by 1,19%.
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Bardin, Thomas, and Tilman Drüeke. Renal osteodystrophy. Oxford University Press, 2013. http://dx.doi.org/10.1093/med/9780199642489.003.0149.
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Renal osteodystrophy (ROD) is a term that encompasses the various consequences of chronic kidney disease (CKD) for the bone. It has been divided into several entities based on bone histomorphometry observations. ROD is accompanied by several abnormalities of mineral metabolism: abnormal levels of serum calcium, phosphorus, parathyroid hormone (PTH), vitamin D metabolites, alkaline phosphatases, fibroblast growth factor-23 (FGF-23) and klotho, which all have been identified as cardiovascular risk factors in patients with CKD. ROD can presently be schematically divided into three main types by histology: (1) osteitis fibrosa as the bony expression of secondary hyperparathyroidism (sHP), which is a high bone turnover disease developing early in CKD; (2) adynamic bone disease (ABD), the most frequent type of ROD in dialysis patients, which is at present most often observed in the absence of aluminium intoxication and develops mainly as a result of excessive PTH suppression; and (3) mixed ROD, a combination of osteitis fibrosa and osteomalacia whose prevalence has decreased in the last decade. Laboratory features include increased serum levels of PTH and bone turnover markers such as total and bone alkaline phosphatases, osteocalcin, and several products of type I collagen metabolism products. Serum phosphorus is increased only in CKD stages 4-5. Serum calcium levels are variable. They may be low initially, but hypercalcaemia develops in case of severe sHP. Serum 25-OH-vitamin D (25OHD) levels are generally below 30 ng/mL, indicating vitamin D insufficiency or deficiency. The international KDIGO guideline recommends serum PTH levels to be maintained in the range of approximately 2-9 times the upper normal normal limit of the assay and to intervene only in case of significant changes in PTH levels. It is generally recommended that calcium intake should be up to 2 g per day including intake with food and administration of calcium supplements or calcium-containing phosphate binders. Reduction of serum phosphorus towards the normal range in patients with endstage kidney failure is a major objective. Once sHP has developed, active vitamin D derivatives such as alfacalcidol or calcitriol are indicated in order to halt its progression.
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Nuevas generaciones sin la infección por el VIH, la sífilis, la hepatitis B y la enfermedad de Chagas en las Américas 2018. ETMI Plus. Organización Panamericana de la Salud, 2019. http://dx.doi.org/10.37774/9789275120675.
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En el presente documento se comunica el progreso logrado en la Región hacia la eliminación de la transmisión maternoinfantil del VIH y la sífilis entre los años 2010 y 2017. Se trata también del primer informe regional sobre la eliminación de la transmisión maternoinfantil y durante la primera infancia de la hepatitis B y la enfermedad de Chagas congénita. Los resultados principales son los siguientes: El acceso de las embarazadas a la atención prenatal y del parto es alto en la Región de las Américas. El tamizaje de la infección por el VIH y la sífilis en las embarazadas sigue siendo alto, pero se han logrado pocos avances para salvar las brechas; por otra parte, el tamizaje de la enfermedad de Chagas en las embarazadas es muy variable, dado que oscila entre 7% y 55% en los pocos países que presentan informes al respecto. El tratamiento de la infección por el VIH y la sífilis en las embarazadas seropositivas sigue en aumento. La vacunación contra la hepatitis B se ha estabilizado en 87% de los menores de 1 año que completan su tercera dosis, aunque continúa en aumento la adopción de políticas de administración de una dosis al nacer de la vacuna contra el virus de la hepatitis B a todos los recién nacidos. Durante mucho tiempo se ha observado una disminución continua de la transmisión maternoinfantil del VIH, pero comienza a estabilizarse. Los casos de sífilis congénita están en aumento. Se considera que la transmisión maternoinfantil causa más de 20% de los casos nuevos de enfermedad de Chagas. This document reports the progress made in the Americas towards the EMTCT of HIV and syphilis between 2010 and 2017. It is the first Regional report regarding elimination of mother-to-child and early childhood transmission of hepatitis B and congenital Chagas disease. The main findings are as follows: Access to prenatal and delivery care for pregnant women is high in the Americas. Screening of pregnant women for HIV and syphilis remains high but little progress has been made in closing the gaps; meanwhile, screening of pregnant women for Chagas disease varies widely, ranging from 7% to 55% among the few reporting countries. HIV and syphilis treatment of seropositive pregnant women continues to increase. Vaccination for hepatitis B has stabilized at 87% of children under one year old who completed their third dose, and policies for universal timely hepatitis B vaccine birth dose are increasingly being adopted. MTCT of HIV experienced longstanding reductions but has begun to stabilize. Congenital syphilis cases are on the rise. Mother-to-child transmission is estimated to cause over 20% of new cases of Chagas disease.