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Healthy children may present acute mountain sickness (AMS) within a few hours after arrival at high altitudes. In few cases, serious complications may occur, including high-altitude pulmonary edema and rarely high-altitude cerebral edema. Those with preexisting conditions especially involving hypoxia and pulmonary hypertension shall not risk travelling to high altitudes. Newborn from low altitude mothers may have prolonged time to complete postnatal adaptation. The number of children and adolescents traveling on commercial aircrafts is growing, and this poses a need for their treating physicians to be aware of the potential risks of hypoxia while air traveling.

Challenges and special aspects related to the management and prognosis of pulmonary hypertension (PH) in middle- to low-income regions (MLIRs) range from late presentation to comorbidities, lack of resources and expertise, cost, and rare options of lung transplantation. Expert consensus recommendations addressing the specific challenges for prevention and therapy of PH in MLIRs with limited resources have been lacking. To date, 6 MLIR-PH registries containing mostly adult patients with PH exist. Importantly, the global prevalence of PH is much higher in MLIRs compared with high-income regions: group 2 PH (left heart disease), pulmonary arterial hypertension associated with unrepaired congenital heart disease, human immunodeficiency virus, or schistosomiasis are highly prevalent. This consensus statement provides selective, tailored modifications to the current PH guidelines to address the specific challenges faced in MLIRs, resulting in the first pragmatic and cost-effective consensus recommendations for PH care providers, patients, and their families.

Challenges and special aspects related to the management and prognosis of pulmonary hypertension (PH) in middle- to low-income regions (MLIRs) range from late presentation to comorbidities, lack of resources and expertise, cost, and rare options of lung transplantation. Expert consensus recommendations addressing the specific challenges for prevention and therapy of PH in MLIRs with limited resources have been lacking. To date, 6 MLIR-PH registries containing mostly adult patients with PH exist. Importantly, the global prevalence of PH is much higher in MLIRs compared with high-income regions: group 2 PH (left heart disease), pulmonary arterial hypertension associated with unrepaired congenital heart disease, human immunodeficiency virus, or schistosomiasis are highly prevalent. This consensus statement provides selective, tailored modifications to the current PH guidelines to address the specific challenges faced in MLIRs, resulting in the first pragmatic and cost-effective consensus recommendations for PH care providers, patients, and their families. ispartof: JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY vol:75 issue:19 pages:2463-2477 ispartof: location:United States status: published

Among the reforms to OTC derivative markets since the global financial crisis is a commitment to collateralize counterparty exposures and to clear standardized contracts via central counterparties (CCPs). The reforms aim to reduce interconnectedness and improve counterparty risk management in these important markets. At the same time, however, the reforms necessarily concentrate risk in one or a few nodes in the financial network and also increase institutions’ demand for high-quality assets to meet collateral requirements. This paper looks more closely at the implications of increased CCP clearing for both the topology and stability of the financial network. Building on Heath et al. (2013) and Markose (2012), the analysis supports the view that the concentration of risk in CCPs could generate instability if not appropriately managed. Nevertheless, maintaining CCP prefunded financial resources in accordance with international standards and dispersing any unfunded losses widely through the system can limit the potential for a CCP to transmit stress even in very extreme market conditions. The analysis uses the Bank for International Settlements Macroeconomic Assessment Group on Derivatives (MAGD) data set on the derivatives positions of the 41 largest bank participants in global OTC derivative markets in 2012.

Objective: To assess the efficacy and safety of the Nit-Occlud ASD-R (PFM S.R.L, La Paz, Bolivia) in the percutaneous closure of secundum atrial septal defects (ASD). Patients and Methods: Fifty-three consecutive patients with median age of 11 years (range 3-67) and mean weight 27.1 kg (range 13-75 kg), treated in two cardiology centers between May 2007 and March 2011. Results: Mean fluoroscopy time was 14 minutes (5-53), mean procedure time was 70 minutes (45-150), mean defect size, as measured by the stop-flow technique, was 17.8 mm (5.6-31), and mean stent size of the implanted device was 18 mm (6-28), which is 0.98 times the defect size. Successful closure of the ASD without major complications was achieved in 49 of 53 patients. In 71.4% of patients in whom device implantation was accomplished, there was no evidence of a persistent shunt at the completion of the procedure. This closure rate increased to 91.7% after 24 hours, with 95.8% closure after three months and 100% closure after six months. Device embolization occurred in one patient within 24 hours of implantation and required surgical device removal and ASD closure. There were no other major complications and no deaths during the period of follow-up (average 72 months; range 59-105 months). Conclusion: The Nit-Occlud ASD-R device is safe and effective with very good closure rates.

The goals of the United Nation's Millennium Summit for reducing maternal mortality have proven difficult to achieve. In Bolivia, where maternal mortality is twice the South American average, improving the diagnosis, treatment and ultimately prevention of preeclampsia is key for achieving targeted reductions. We held a workshop in La Paz, Bolivia to review recent revisions in the diagnosis and treatment of preeclampsia, barriers for their implementation, and means for overcoming them. While physicians are generally aware of current recommendations, substantial barriers exist for their implementation due to geographic factors increasing disease prevalence and limiting health-care access, cultural and economic factors affecting the care provided, and infrastructure deficits impeding diagnosis and treatment. Means for overcoming such barriers include changes in the culture of health care, use of standardized diagnostic protocols, the adoption of low-cost technologies for improving the diagnosis and referral of preeclamptic cases to specialized treatment centers, training programs to foster multidisciplinary team approaches, and efforts to enhance local research capacity. While challenging, the synergistic nature of current barriers for preeclampsia diagnosis and treatment also affords opportunities for making far-reaching improvements in maternal, infant and lifelong health.

BackgroundInterventional closure of patent arterial duct has become an accepted alternative to surgical closure. Clinical trial with “Nit-Occlud® PDA-R”.Methods and resultsTo assess the safety and efficacy of the device, we performed a prospective clinical study between June, 2009 and December, 2010 in La Paz, Bolivia. In all, 29 – 22 female patients and 7 male patients – out of 59 patients were selected on the basis of inclusion criteria. The procedures were performed under sedation at an age and weight of 5.7 years and 22.7 kilograms, respectively, with 4–6 French arterial sheaths and 5–7 French venous sheaths. The minimal diameter of the duct was 3.5 millimetres. The procedure, fluoroscopy, and hospitalisation times were 96.4 minutes (55 to 145), 13.1 minutes (3 to 25.2), and 24 hours, respectively. The “Nit-Occlud® PDA-R” was successfully deployed in all patients. Immediate, 24-hour, 1-, 3-, and 6-month closure rates were 65.5%, 79.3%, 96.5%, and 100%, respectively. The systolic pulmonary pressure diminished from 37 millimetres of mercury (21 to 57) before the intervention to 31 millimetres of mercury (21 to 45) after the intervention. No early or late embolisation, haemolysis, left pulmonary artery, or descending aorta obstruction occurred.ConclusionsWe conclude that the “Nit-Occlud® PDA-R” device is safe and effective in closing patent arterial duct up to a diameter of 8 millimetres.

Among the reforms to over-the-counter (OTC) derivative markets since the global financial crisis is a commitment to collateralise counterparty exposures and to clear standardised contracts via central counterparties (CCPs). The reforms aim to reduce interconnectedness and improve counterparty risk management in these important markets. At the same time, however, the reforms necessarily concentrate risk in one or a few CCPs and also increase institutions' demand for high-quality assets to meet collateral requirements. This paper looks more closely at the implications of these reforms for the stability of the financial network. Following Heath, Kelly and Manning (2013), the paper examines liquidity and solvency risk under alternative clearing configurations, but extends the analysis in two main ways. First, rather than using simulated data, it uses actual data on the derivative positions of the 41 largest bank participants in global OTC derivative markets in 2012 (as previously used by the Bank for International Settlements' Macroeconomic Assessment Group on Derivatives). Second, it extends the methodolgy to consider in greater depth the implications of loss allocation by CCPs to meet obligations once pre-funded financial resources have been exhausted, and in particular the mechanism of variation margin gains haircutting. This mechanism is considered in international standard-setters' guidance on recovery planning for CCPs and has been adopted by some CCPs. The paper demonstrates that designing and operating CCPs in accordance with international standards can limit the potential for stress to propagate through the system, even in very extreme market conditions.

One of the most important measures of the state of the labour market is the unemployment rate. However, the standard definition of unemployment ignores an important group of people who are not employed but who want to work – the marginally attached workforce. The marginally attached are defined as those who are not employed, want to work but are not actively seeking work and therefore not classified as unemployed. The paper uses longitudinal data from the Survey of Employment and Unemployment Patterns (SEUP) to test whether the marginally attached are behaviourally distinct from the unemployed or those who are not attached to the labour force. We find that the labour force transitions of the marginally attached, on the whole, are between those of the unemployed and the unattached. Another finding is that the length of time over which the labour market dynamics are considered is crucial to our understanding of the labour market dynamics of the marginally attached. An implication of the findings of this paper is that a range of measures of potential labour supply should be considered, and that the measure used should depend on the specific question being asked.

This paper describes the Australian banking system, highlighting ways in which it differs from other major banking systems. It draws together themes from previous work conducted at the Reserve Bank of Australia (RBA), and outlines the role the banking system plays in the transmission of monetary policy and the transformation of risk. The paper also discusses some more recent trends, including the increased focus on deposit funding and potential changes in the determination of lending rates due to changes in the pricing of risk. These trends are, in turn, being influenced by changes in the preferences towards, and understanding of, different types of risk by investors, banks' management and regulators.

In Australia, as in most industrialised countries, there has been a dramatic increase in unemployment rates over the last three decades. The teenage labour market, in particular, has undergone significant structural changes which have resulted in large increases in the rate of unemployment among teenagers. The proportion of children staying on at school past the minimum leaving age and higher-education participation rates have also been rising over this period. Despite this, the overall full-time education participation of Australian teenagers remains low compared with that in most other OECD nations.

Las clasificaciones actuales de la hipertensión pulmonar han contribuido significativamente al conocimiento de la enfermedad vascular pulmonar, han facilitado ensayos farmacológicos y han mejorado nuestro conocimiento de las cardiopatías congénitas del adulto; sin embargo estas clasificaciones no son aplicables completamente a la enfermedad en el niño. La clasificación que aquí se propone se basa principalmente en la práctica clínica. Los objetivos específicos de esta nueva clasificación son mejorar las estrategias diagnósticas, promover la investigación clínica, mejorar nuestro conocimiento de la patogénesis, de la fisiología y de la epidemiología de la enfermedad y orientar el desarrollo de modelos de la enfermedad humana en el laboratorio y estudios en animales; también puede servir como un recurso docente. Se hace énfasis en los conceptos de maladaptación perinatal, alteraciones del desarrollo e hipoplasia pulmonar como factores causantes de la hipertensión pulmonar pediátrica; así mismo, en la importancia de los múltiples síndromes malformativos congénitos, genéticos y cromosómicos en la presentación de la hipertensión pulmonar pediátrica. La enfermedad vascular pulmonar hipertensiva en niños se divide en diez grandes categorías. Current classifications of pulmonary hypertension have contributed a great deal to our understanding of pulmonary vascular disease, facilitated drug trials, and improved our understanding of congenital heart disease in adult survivors. However, these classifications are not applicable readily to pediatric disease. The classification system that we propose is based firmly in clinical practice. The specific aims of this new system are to improve diagnostic strategies, to promote appropriate clinical investigation, to improve our understanding of disease pathogenesis, physiology and epidemiology, and to guide the development of human disease models in laboratory and animal studies. It should be also an educational resource. We emphasize the concepts of perinatal maladaptation, maldevelopment and pulmonary hypoplasia as causative factors in pediatric pulmonary hypertension. We highlight the importance of genetic, chromosomal and multiple congenital malformation syndromes in the presentation of pediatric pulmonary hypertension. We divide pediatric pulmonary hypertensive vascular disease into 10 broad categories.

Los miembros del Task Force pediátrico del Pulmonary Vascular Research Institute (PVRI, su sigla en Inglés) fueron conscientes de la necesidad de desarrollar una clasificación funcional de la hipertensión pulmonar en niños. La clasificación que se propone sigue el mismo patrón y utiliza los mismos criterios de la clasificación de la hipertensión pulmonar específica para adultos de Dana Point. Fue necesario incluir modificaciones para los niños, teniendo en cuenta que la edad, el crecimiento físico y la madurez influyen en la expresión funcional de la enfermedad. Es necesario definir el estado clínico del niño, pues ello facilita revisar la evolución del mismo en una forma consistente y objetiva a medida que él/ella crecen. Particularmente en los niños más jóvenes, se trató de incluir indicadores objetivos como el crecimiento, la necesidad de alimentos suplementarios y los registros de asistencia al colegio y a la guardería. Esto ayuda a monitorear la evolución clínica y la respuesta al tratamiento a través de los años y facilita el desarrollo de algoritmos de tratamiento en estos pacientes. Se presenta un artículo de consenso sobre una clasificación aplicable a los niños con hipertensión pulmonar que se discutió en la reunión anual del PVRI que se llevó a cabo en Panamá en febrero de 2011. The members of the Pediatric Task Force of the Pulmonary Vascular Research Institute (PVRI) were aware of the need to develop a functional classification of pulmonary hypertension in children. The proposed classification follows the same pattern and uses the same criteria as the Dana Point pulmonary hypertension specific classification for adults. Modifications were necessary for children, since age, physical growth and maturation influences the way in which the functional effects of a disease are expressed. It is essential to encapsulate a child's clinical status, to make it possible to review progress with time as he/she grows up, as consistently and as objectively as possible. Particularly in younger children we sought to include objective indicators such as thriving, need for supplemental feeds and the record of school or nursery attendance. This helps monitor the clinical course of events and response to treatment over the years. It also facilitates the development of treatment algorithms for children. We present a consensus paper on a functional classification system for children with pulmonary hypertension, discussed at the Annual Meeting of the PVRI in Panama City, February 2011.

Liquid assets with low credit and market risk have a number of uses in financial markets, such as providing collateral against short-term funding or credit exposures that arise between counterparties to financial transactions. This article examines the existing sources of demand for Australian dollar-denominated liquid assets. Given relatively low levels of government debt in Australia, demand for these assets has been increasing relative to supply for some time. A further increase in demand arising from regulatory changes designed to improve the management of liquidity risk and counterparty credit risk will accentuate this trend.

The introduction of electronic broking to the foreign exchange market in the early 1990s signalled the start of a process of innovation that has driven significant change. This article looks at the evolution of electronic trading in the global foreign exchange market and focuses on its impact on the behaviour of banks globally and in the Australian market.

Around 140 million people in the world, including 4.9 million Bolivians, live 2,500 m above sea level. The barometric pressure and the partial pressure of oxygen in the blood fall in direct proportion to the altitude. The time necessary for a person living at sea level to adapt to the altitude depends, in direct proportion, on the altitude at which that person arrives. Living, working, and playing sports at high altitudes are considered by many a great feat. In fact, there is controversy about the feasibility of playing competitive sports in cities located at very high altitudes. However, native inhabitants may play soccer at altitudes even higher than the summit of Mt Sajama, located 6,000 m above sea level. Traveling to high altitudes as a lowland immigrant is considered a risk. In one renowned article, discussing altitude, it was stated that the altitude causes more than mere muscular fatigue; it affects memory, calculating capacity, decision-making ability, and judging capacity. What are the adaptive mechanisms that help people live and work with relative normality in these high regions? Many working groups have worked to understand the physiological mechanisms of adaptation to the altitude for newcomers and the connotations of living in mountains for many generations. These studies have dealt not only with hypobaric hypoxia, but also with lower temperatures, low humidity levels, and increased solar radiation. Temperature and the amount of UV radiation also vary with the altitude: the temperature decreases by 6.5°C per 1,000 m and the amount of radiation increases at a rate of 4% per 1,000 m. However, the inhabitant at high altitudes has found a balance based on adaptive processes. With regard to congenital heart defects, the factors mentioned previously, combined with the lower socioeconomic level, have contributed to a higher incidence of these types of disorders at altitude.

Background: Patent ducti arteriosi (PDAs) are more frequent and larger at high altitude than at sea level. A novel PDA closure device, the Nitocclud PDA-R, is designed specifically for both large and medium size PDAs. The initial clinical experience with a new nitinol-based device in high altitude patients with large PDAs is described. Methods: The Nitocclud PDA-R is a self-expandable, self-centering, repositionable occluder made of one nitinol wire without use of welding. It contains several polyester membranes, is delivered with a central guide wire and is released by retraction of the central wire into the delivery catheter. The efficacy of this device was evaluated at several high altitude centers. Results: Fifty-one patients without other congenital cardiac defects underwent transcatheter closure of PDA. Complete occlusion of the PDA was achieved in 98% of the patients. Nearly 49% of the patients had no shunt immediately after device implantation. Echocardiography revealed a complete closure rate by Doppler interrogation of 69% after 24 hr, 96% after 6 months, and 98% after 1 year. In two cases, device embolization was observed after release, and in both cases the device was easily retrieved with standard interventional techniques. There have been no episodes of delayed device migration, endocarditis, hemolysis, wire fracture, device disruption, or death. Conclusions: The Nitocclud PDA-R device is safe and effective and can easily close very large PDAs. This device has a high rate of complete occlusion within 1 year and is easily retrieved if embolized. © 2011 Wiley Periodicals, Inc.

Objectives: Aim of our study was the preclinical evaluation of a new self expanding device for interventional closure of muscular ventricular septal defects (mVSDs) in an acute pig model. Background: Devices currently in use for closure of mVSDs still have their limitations. The deployment of the disks is dependent from the expansion of the stent, which can be associated with problems for sufficient closure of the mVSDs. This was the reason for developing a modified device with only one disk Materials and Methods: The device was constructed in a single wire technique with a unique configured retention disk. mVSDs were created in six pigs with a specially designed punch instrument, and subsequently closed with our new device during the same session using a jugular or femoral vein approach. Potential residual shunting volumes were estimated by echocardiography and hemodynamic measurements. After closure, animals were sacrificed, and hearts were harvested for macropathologic evaluation. In two animals, MRI was performed for additional noninvasive evaluation. Results: Devices were successfully implanted in all animals with good alignment of the disk to the left ventricular septum, even if the stent was oversized. Echocardiography, hemodynamics, angiography and macropathology revealed complete closure of all mVSDs. MRI and echocardiography showed a good visibility of the device. Conclusions: Our preclinical study shows successful closure of iatrogenic created mVSDs without residual shunting. The device is characterized by a more controlled deployment, an independent deployment of disk and waist, and a good alignment of the left ventricular disk to the muscular septum. © 2009 Wiley-Liss, Inc.

Over the past decade or so, the spread of electronic trading has brought about significant changes in the structure of the interbank foreign exchange markets and the relationship between foreign exchange dealers and their clients. This article looks at the way foreign exchange transactions are executed based on the BIS triennial survey data, and provides some quantitative estimates of the importance of electronic trading across transaction types, counterparties and economies.

The increasing size and concentration of official foreign exchange reserves after years of continued expansion, especially since the Asian crisis, have led to renewed interest in the way reserve management decisions are taken and in their possible impact on financial markets. Reserve management practices have evolved substantially over the past decade or so, reflecting changes in both the economic and the broader institutional environment. While some of these changes have been remarked upon, others have attracted less attention. This paper documents some of the main changes in foreign exchange reserve management practices, considers the main drivers behind them, and explores some of the challenges ahead. We focus, in particular, on those challenges that could have a more significant impact on financial markets. These include the choice of an appropriate balance between risk and return, of the numeraire currency and of the degree of public disclosure, from which some conclusions are drawn concerning the future of the US dollar as a reserve currency and volatility in financial markets. The discussion relies extensively on a survey of central banks and monetary authorities representing in total about 80% of global foreign exchange reserves at end-2006.

In recent years, issues related to the management of foreign exchange reserves have gained prominence, and reserve management practices have evolved rapidly. Against this background, the Monetary and Economic Department of the Bank for International Settlements organised an ad hoc meeting of senior central bankers from both industrial and emerging market countries responsible for the management of reserves, which took place on 1-2 March 2007. The meeting covered key issues in foreign exchange reserve management, including the broad framework in which it is conducted, asset allocation at the strategic, tactical and portfolio management levels, risk measurement and management, organisational structures and disclosure. This paper was prepared as background and provides a general framework to help organise the various issues that arise in the context of FX reserve management.

The most recent BIS triennial survey shows that turnover in foreign exchange markets increased by more than 70% over the three years to April 2007. Two specific findings stand out. First, the growth in transactions between banks and other financial institutions was particularly strong, consistent with the increasing importance of hedge funds, as well as portfolio diversification by institutional investors with a longer-term horizon, such as pension funds. Second, there has been a marked increase in turnover involving emerging market currencies.

Commodities have attracted considerable interest as a financial investment in recent years. This article discusses the factors behind their growing appeal and assesses the extent to which market characteristics, such as price volatility, have changed as a result. The feature concludes that commodity markets have become more like financial markets in terms of the motivations and strategies of participants, but that the physical characteristics of commodity markets are still important.

Interest rate differentials have been a driving force behind exchange rate movements in recent years. This has focused market attention on the role of currency carry trade positions, and on the possibility that a sudden unwinding might adversely affect financial stability. However, carry trades are notoriously difficult to track in the available data. This special feature first outlines the investor base and trading strategies used in carry trades, and then explores various sources of data to gauge activity.

Despite a significant deterioration in the US net foreign asset position, there has not been a corresponding deterioration in the net income balance. In fact, there has generally been a net income surplus. Two factors have been particularly important for the positive net income balance over the past 15 years or so. The first is that the United States has a positive net external equity balance and a negative net external debt balance. This contributes to a net income surplus because the income yield on equity has been higher than the income yield on debt. The second factor is that the United States earns a persistently higher income yield on its foreign direct investment (FDI) assets than foreigners earn on their direct investments in the United States. This paper summarises the evidence from firm-level studies and time-series data for the United States, as well as cross-country comparisons, to weigh up alternative explanations for this outcome. The evidence presented suggests that differences in income yields on FDI are not explained by the presence of large stocks of unmeasured assets. Moreover, they do not appear to be related to different characteristics of the investment such as industry composition or riskiness. There is some evidence that differences in the average maturity of investment have had some effect on yield differentials, especially in the 1980s. There are also incentives to minimise taxes that are consistent with the relatively low income yields earned on FDI in the United States, but no firm evidence that this is an important explanation.

One of the key factors that affects the extent to which changes in labour demand affect other macroeconomic variables, such as wage inflation, is the degree of matching between potential employees and available jobs. The pool of potential employees is usually measured as the pool of unemployed workers. However, this ignores an important group of people who are not officially unemployed, but do represent potential labour supply the marginally attached workforce, which can be broadly defined as the people who are not currently in the labour force, but want to work and are available to take up employment. The aim of this paper is to examine the extent to which the labour market behaviour of marginally attached workers is similar to that of the unemployed. We use longitudinal data from the Survey of Employment and Unemployment Patterns (SEUP), which provides detailed information on the characteristics of individuals as well as their labour market experiences, to compare dynamic behaviour across labour market groups, for example, the probability of moving into employment. We find that in some respects the dynamic behaviour of the marginally attached is similar to that of the unemployed, but in others it is quite different. Accordingly, the most appropriate measure of labour supply depends on the policy question, and consequently a range of measures should be considered.

This paper explores the extent to which Knightian uncertainty can explain features of interest rate paths observed in practice that are not generally replicated by models of optimal monetary policy. Interest rates tend to move in a sequence of steps in a given direction, or remain constant for some time, rather than experiencing the frequent reversals that commonly arise from optimal policy simulations. We categorise the types of uncertainty that have been explored to date in terms of the decision-making behaviour they imply. From this, we suggest a more intuitively appealing formulation of Knightian uncertainty than the one that has previously been used in the analysis of monetary policy. Within a very simple optimal control problem, we show that our preferred formalisation is consistent with interest rate paths with periods of no change. This suggests that the presence of Knightian uncertainty may explain some features of monetary policy-makers’ behaviour.

Survey data suggest that unemployed teenagers look for work in ways that differ significantly from the ways which proved successful for teenagers who found work. This paper examines what factors affect the way teenagers look for work in order to explain why we observe this behaviour. We find that the single most important characteristic for explaining the job-search method choices of Australian teenagers is whether they receive unemployment benefits. Receiving benefits increases the probability of teenagers using the government employment agency as the main job-search method by almost 20 percentage points, and decreases their probability of using direct methods (such as contacting employers or friends and relatives) or newspapers by around 10 percentage points each. Personal characteristics and family background are also important for understanding the job-search methods chosen by unemployed teenagers. Another interesting finding is that the local environment, especially the state of the local labour market, is important for explaining job-search method choice. Higher local unemployment rates decrease the probability that an unemployed teenager will use direct search methods, and increase the probability that they will use the government employment agency. These results may help to explain the recently documented evidence that unemployment has become increasingly concentrated in low-socioeconomic-status neighbourhoods (Gregory and Hunter 1995).

This paper investigates those factors which affect the duration of unemployment of Australian job seekers. The analysis uses data on individual job seekers from the Survey of Employment and Unemployment Patterns (SEUP) to assess the influence of a comprehensive array of personal and background characteristics on the duration of unemployment. The data set also provides job seekers’ responses concerning their minimum acceptable (or reservation) wage. The results suggest that around one-fifth of adult unemployed job seekers would be willing to work for a wage less than the legal minimum. It is also found that a job seekers’ reservation wage has little effect on his/her unemployment duration. Instead, the binding constraint for job seekers appears to be that they receive very few job offers. Although legal minimum wages could be part of the story, more research is required to properly understand their role in the dynamics of the labour market.

This paper poses two questions: why did the equilibrium rate of unemployment rise so much in the 1970s, and why does unemployment increase rapidly during recessions, but decrease so slowly in the subequent recovery, i.e. why is unemployment persistent? We find that equilibrium unemployment rose because of the economy’s inability to adjust to the adverse shocks of the time; employment contracted in some sectors but did not expand sufficiently in others. In answer to the second question, we find that the sources of persistence are different for men and women. Male unemployment has been persistent because, following a recession, employment is created in female dominated sectors, rather than the male dominated sectors which experienced the greatest decline in employment. Female unemployment has been persistent because the growth in the demand for female labour has been matched by the growth in its supply. Finally, we find that recessions appear to have a permanent effect on the sectoral composition of the economy; i.e., recessions are periods of accelerated structural change.

Las clasificaciones actuales de la hipertensión pulmonar han contribuido significativamente al conocimiento de la enfermedad vascular pulmonar, han facilitado ensayos farmacológicos y han mejorado nuestro conocimiento de las cardiopatías congénitas del adulto; sin embargo estas clasificaciones no son aplicables completamente a la enfermedad en el niño. La clasificación que aquí se propone se basa principalmente en la práctica clínica. Los objetivos específicos de esta nueva clasificación son mejorar las estrategias diagnósticas, promover la investigación clínica, mejorar nuestro conocimiento de la patogénesis, de la fisiología y de la epidemiología de la enfermedad y orientar el desarrollo de modelos de la enfermedad humana en el laboratorio y estudios en animales; también puede servir como un recurso docente. Se hace énfasis en los conceptos de maladaptación perinatal, alteraciones del desarrollo e hipoplasia pulmonar como factores causantes de la hipertensión pulmonar pediátrica; así mismo, en la importancia de los múltiples síndromes malformativos congénitos, genéticos y cromosómicos en la presentación de la hipertensión pulmonar pediátrica. La enfermedad vascular pulmonar hipertensiva en niños se divide en diez grandes categorías.Current classifications of pulmonary hypertension have contributed a great deal to our understanding of pulmonary vascular disease, facilitated drug trials, and improved our understanding of congenital heart disease in adult survivors. However, these classifications are not applicable readily to pediatric disease. The classification system that we propose is based firmly in clinical practice. The specific aims of this new system are to improve diagnostic strategies, to promote appropriate clinical investigation, to improve our understanding of disease pathogenesis, physiology and epidemiology, and to guide the development of human disease models in laboratory and animal studies. It should be also an educational resource. We emphasize the concepts of perinatal maladaptation, maldevelopment and pulmonary hypoplasia as causative factors in pediatric pulmonary hypertension. We highlight the importance of genetic, chromosomal and multiple congenital malformation syndromes in the presentation of pediatric pulmonary hypertension. We divide pediatric pulmonary hypertensive vascular disease into 10 broad categories.

Standardization of the diagnostic routine for children with congenital heart disease associated with pulmonary arterial hypertension (PAH-CHD) is crucial, in particular since inappropriate assignment to repair of the cardiac lesions (e.g., surgical repair in patients with elevated pulmonary vascular resistance) may be detrimental and associated with poor outcomes. Thus, members of the Congenital Heart Disease and Pediatric Task Forces of the Pulmonary Vascular Research Institute decided to conduct a survey aimed at collecting expert opinion from different institutions in several countries, covering many aspects of the management of PAH-CHD, from clinical recognition to noninvasive and invasive diagnostic procedures and immediate postoperative support. In privileged communities, the vast majority of children with congenital cardiac shunts are now treated early in life, on the basis of noninvasive diagnostic evaluation, and have an uneventful postoperative course, with no residual PAH. However, a small percentage of patients (older at presentation, with extracardiac syndromes or absence of clinical features of increased pulmonary blood flow, thus suggesting elevated pulmonary vascular resistance) remain at a higher risk of complications and unfavorable outcomes. These patients need a more sophisticated diagnostic approach, including invasive procedures. The authors emphasize that decision making regarding operability is based not only on cardiac catheterization data but also on the complete diagnostic picture, which includes the clinical history, physical examination, and all aspects of noninvasive evaluation.