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The continued and dramatic rise in the size of data sets has meant that new methods are required to model and analyze them. This timely account introduces topological data analysis (TDA), a method for modeling data by geometric objects, namely graphs and their higher-dimensional versions: simplicial complexes. The authors outline the necessary background material on topology and data philosophy for newcomers, while more complex concepts are highlighted for advanced learners. The book covers all the main TDA techniques, including persistent homology, cohomology, and Mapper. The final section focuses on the diverse applications of TDA, examining a number of case studies drawn from monitoring the progression of infectious diseases to the study of motion capture data. Mathematicians moving into data science, as well as data scientists or computer scientists seeking to understand this new area, will appreciate this self-contained resource which explains the underlying technology and how it can be used.
Ascending aortic dilation is a feared complication in adults with repaired coarctation of the aorta, as the condition is associated with life-threatening complications such as aortic dissection and rupture. However, the data are currently limited regarding factors associated with ascending aortic dilation in these patients.
Methods and results:
From the national register of congenital heart disease, 165 adult patients (≥ 18 years old) with repaired coarctation of the aorta, and echocardiographic data on aortic dimensions, were identified (61.2% male, mean age 35.8 ± 14.5 years). Aortic dilation (aortic diameters > 2 SD above reference mean) was found in 55 (33.3%) of the 165 included patients, and was associated with manifest aortic valve disease in univariable logistic regression analysis (OR 2.44, 95% CI [1.23, 4.83]).
Aortic dilation is common post-repair of coarctation of the aorta, and is associated with manifest aortic valve disease and thus indirectly with the presence of a bicuspid aortic valve. However, no association was found between aortic dilation and age or blood pressure.
The aim of this study was to assess exercise capacity, physical activity, and health-related quality of life within a broad and unselected group of adults with CHD.
From April 2009 to February 2014, 1310 patients were assessed for suitability to participate in this single-centre cross-sectional study. Seven hundred and forty-seven (57%) patients were included, performed a submaximal bicycle test, and answered questionnaires regarding physical activity and health-related quality of life. Exercise capacity, physical activity, and health-related quality of life were compared with reference values and correlations were studied.
The exercise capacities of men and women with CHD were 58.7 and 66.3%, respectively, of reference values. Approximately, 20–25% of the patients did not achieve the recommended amount of physical activity. In addition, men scored significantly less points on 7 out of 10 scales of health-related quality of life and women in 6 out of 10 scales, compared with reference values. The strongest correlation was between exercise capacity and the Short Form-36 (physical function).
Exercise capacity was impaired in all adults with CHD, including those with less complicated CHD. One-quarter of the patients did not achieve the recommended levels of physical activity. Exercise tests followed by individualised exercise prescriptions may be offered to all patients with CHD aiming to increase exercise capacity, levels of physical activity, improve health-related quality of life, and reduce the risk of acquired life-style diseases.
Adult foreign language acquisition is challenging, and the degree of success varies among individuals. Anatomical differences in brain structure prior to training can partly explain why some learn more than others. We followed a sample of conscript interpreters undergoing intense language training to study learning-related changes in white-matter microstructure (FA, MD, RD and AD) and associations between differences in brain structure prior to training with acquired language proficiency. No evidence for changes in white matter microstructure relative to a control group was found. Starting values of RD, AD and MD were positively related to final test scores of language proficiency, corroborating earlier findings in the field and highlighting the need for further study of how initial brain structure influences and interacts with learning outcomes.
Arterial hypertension is common in adults with repaired coarctation of the aorta, and is associated with several severe complications.
This study aimed to investigate the prevalence of poorly controlled (⩾140/90 mmHg) blood pressure among patients with diagnosed hypertension and to identify associated factors.
In the national register for CHD, adults with repaired coarctation of the aorta and diagnosed hypertension – defined as a registry diagnosis and/or use of anti-hypertensive prescription medication – were identified. Logistic regression analysis was used to identify variables associated with poorly controlled blood pressure.
Of the 243 included patients, 27.2% were female, the mean age was 45.4±15.3 years, and 52.3% had poorly controlled blood pressure at the last registration. In a multivariable model, age (years) (OR 1.03, CI 1.01–1.06, p=0.008) was independently associated with poorly controlled blood pressure and so was systolic arm–leg blood pressure gradient in the ranges [10, 20] mmHg (OR 4.92, CI 1.76–13.79, p=0.002) to >20 mmHg (OR 9.93, CI 2.99–33.02, p<0.001), in comparison with the reference interval [0, 10] mmHg. Patients with poorly controlled blood pressure had, on average, more types of anti-hypertensive medication classes prescribed (1.9 versus 1.5, p=0.003).
Poorly controlled blood pressure is common among patients with repaired coarctation of the aorta and diagnosed hypertension, despite what seems to be more intensive treatment. A systolic arm–leg blood pressure gradient is associated with poorly controlled blood pressure, even at low levels usually not considered for intervention, and may be an indicator of hypertension that is difficult to treat.
The last decade has seen a vast increase in the use of patient-reported outcomes. As patient-reported outcomes are used in order to capture patients’ perspectives of their health and illness, it is a prerequisite for accurate patient-reported outcome evaluations to use representative samples. In order to evaluate representativeness, the present study focussed on the comparison between participants and non-participants in the Swedish branch of the international study APPROACH-IS (Assessment of Patterns of Patient-Reported Outcomes in Adults with Congenital Heart disease – International Study), regarding demographic, clinical, and health status characteristics.
Eligible patients for APPROACH-IS were identified and selected from SWEDCON, the Swedish registry for congenital heart disease (CHD). Overall, 912 eligible patients were identified, of whom 471 participated, 398 did not participate, and 43 were either unreachable or declined to participate in APPROACH-IS. The participants and non-participants were compared in terms of statistical significance and effect sizes.
Significant differences were observed between participants and non-participants for sex, age, primary diagnosis, number of cardiac operations, and fatigue; however, the effect sizes were in general small, except for the difference in primary diagnosis. No differences between the two groups were found in number of catheterisations, implanted device, the distribution of NYHA functional class, or health status and symptoms.
This study shows that participants and non-participants are relatively comparable groups, which confirms the representativeness of the participants. The Swedish data from APPROACH-IS can therefore be reliably generalised to the population of adults with CHD in Sweden.
To examine the use of vitamin D supplements during infancy among the participants in an international infant feeding trial.
Information about vitamin D supplementation was collected through a validated FFQ at the age of 2 weeks and monthly between the ages of 1 month and 6 months.
Infants (n 2159) with a biological family member affected by type 1 diabetes and with increased human leucocyte antigen-conferred susceptibility to type 1 diabetes from twelve European countries, the USA, Canada and Australia.
Daily use of vitamin D supplements was common during the first 6 months of life in Northern and Central Europe (>80 % of the infants), with somewhat lower rates observed in Southern Europe (>60 %). In Canada, vitamin D supplementation was more common among exclusively breast-fed than other infants (e.g. 71 % v. 44 % at 6 months of age). Less than 2 % of infants in the USA and Australia received any vitamin D supplementation. Higher gestational age, older maternal age and longer maternal education were study-wide associated with greater use of vitamin D supplements.
Most of the infants received vitamin D supplements during the first 6 months of life in the European countries, whereas in Canada only half and in the USA and Australia very few were given supplementation.
A novel cryogenic electrostatic storage device consisting of two ion-beam storage rings with a common straight section for studies of interactions between oppositely charged ions at low and well-defined relative velocities is under construction at Stockholm University. Here we consider the prospect of using this new tool to measure cross-sections and rate coefficients for mutual neutralization reactions of importance in interstellar ion chemistry in general and specifically in cosmic pre-biotic ion chemistry.