Objectives: To estimate annual changes and trends in the population of informal carers and to investigate transitions to caregiving by age, gender, locus of care, and level of involvement. Design: Longitudinal analysis of data from the British household panel survey, 1991 to 1998, an annual prospective survey of a nationally representative sample of more than 5000 private households in England,...

Genetic and environmental influences on cognitive components of reading span in 345 middle-aged male twin pairs were examined. Shared variance among word recognition (reading only), digits forward (short-term memory only), and reading span (concurrent reading plus memory) was almost entirely mediated by common genetic influences. Overall heritability was .52 for word recognition, .27 for digits...

BACKGROUND Heritability may play a role in nonfamilial atrial fibrillation (AF). We hypothesized that a monozygotic (MZ) twin whose co-twin was diagnosed with AF would have an increased risk of the disease compared with a dizygotic (DZ) twin in the same situation. METHODS AND RESULTS A sample of 1137 same-sex twin pairs (356 MZ and 781 DZ pairs) in which one or both members were diagnosed wit...

Hybrid systems combining distributed Raman amplification and phase-sensitive amplifiers (PSAs) are investigated in numerical simulations. We focus on the mitigation of fiber nonlinearities and the impact of the span power map which is also important in systems employing optical phase conjugation or phase-conjugated twin waves. We simulate multi-span PSA links with and without distributed Raman ...

In this work a model to estimate the efficiency of natural ventilation in a commercial twin-span greenhouse is presented. A numerical simulation approach was adopted using the theory of three-dimensional computational fluid dynamics (CFD). With this approach, it was able to generate three-dimensional patterns for temperature and airspeed inside the greenhouse, using specific boundary conditions...

The primary aim of the Michigan State University Twin Registry (MSUTR) is to examine developmental differences in genetic, environmental, and neurobiological influences on internalizing and externalizing symptoms, with disordered eating and antisocial behavior representing particular areas of interest. Twin participants span several developmental stages (i.e., childhood, adolescence, and young ...

Long-span cable-stayed bridges often have a design service life of more than hundred years, during which they may experience multiple earthquake events and accumulate seismic damage if are located in seismic-prone regions. Earthquake occurrence is discretely randomly distributed over the cycle long-span bridge causes sudden drops structural performance instead yearly fixed degradation. This stu...

OBJECTIVE The relationship between personality and life span is not well understood, and no study to date has examined genetic influences underlying this relationship. The present study aimed to explore the phenotypic and genetic relationship between personality and life span, as well as genetic influences on all-cause mortality. METHODS Prospective community-based study including 3752 twin i...

Previous twin studies have indicated that approximately 25% of the variation in life span can be attributed to genetic factors and recent studies have also suggested a moderate clustering of extreme longevity within families. Here we discuss various definitions of extreme longevity and some analytical approaches with special attention to the challenges due to censored data. Lexis diagrams are p...