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Mortality risk is known to be associated with many physiological or biochemical risk factors, and polygenic risk scores (PRSs) may offer an additional or alternative approach to risk stratification. We have compared the predictive value of common biochemical tests, PRSs and information on parental survival in a cohort of twins and their families. Common biochemical test results were available for up to 13,365 apparently healthy men and women, aged 17−93 years (mean 49.0, standard deviation [SD] 13.7) at blood collection. PRSs for longevity were available for 14,169 study participants and reported parental survival for 25,784 participants. A search for information on date and cause of death was conducted through the Australian National Death Index, with median follow-up of 11.3 years. Cox regression was used to evaluate associations with mortality from all causes, cancers, cardiovascular diseases and other causes. Linear relationships with all-cause mortality were strongest for C-reactive protein, gamma-glutamyl transferase, glucose and alkaline phosphatase, with hazard ratios (HRs) of 1.16 (95% CI [1.07, 1.24]), 1.15 (95% CI 1.04–1.21), 1.13 (95% CI [1.08, 1.19]) and 1.11 (95% CI [1.05, 1.88]) per SD difference, respectively. Significant nonlinear effects were found for urea, uric acid and butyrylcholinesterase. Lipid risk factors were not statistically significant for mortality in our cohort. Family history and PRS showed weaker but significant associations with survival, with HR in the range 1.05 to 1.09 per SD difference. In conclusion, biochemical tests currently predict long-term mortality more strongly than genetic scores based on genotyping or on reported parental survival.
Invasive species drive biodiversity loss and lead to changes in parasite–host associations. Parasites are linked to invasions and can mediate invasion success and outcomes. We review theoretical and empirical research into parasites in biological invasions, focusing on a freshwater invertebrate study system. We focus on the effects of parasitic infection on host traits (behaviour and life history) that can mediate native/invader trophic interactions. We review evidence from the field and laboratory of parasite-driven changes in predation, intraguild predation and cannibalism. Theoretical work shows that the trait-mediated effects of parasites can be as strong as classical density effects and their impact on the host’s trophic interactions merits more consideration. We also report on evidence of broader cascading effects warranting deeper study. Biological invasion can lead to altered parasite–host associations. Focusing on amphipod invasions, we find patterns of parasite introduction and loss that mirror host invasion pathways, but also highlight the risks of introducing invasive parasites. Horizon scanning and impact predictions are vital in identifying future disease risks, potential pathways of introduction and suitable management measures for mitigation.
We summarise processes determining large-scale patterns of distribution and abundance of macroinfauna from Florida to Newfoundland, ~25°N to 52°N, focussing on intertidal and shallow subtidal (~ 5 m depth) muddy sands and sandy muds, habitats with abundant experimental data. Within the theme of geographic distribution of processes, mechanisms and patterns we suggest latitudinal patterns will likely change most as climate changes intensify. Published studies support the following major biogeographic patterns: (1) reduced importance of large disturbance predators north of Cape Cod, driven by latitudinal shifts in thermal regimes; (2) large digging predators from Delaware Bay (39.25°N) southwards dramatically reduce infaunal densities, restricting competitive interactions; (3) disturbance refugia, e.g., Zostera, drive southern spatial patterns; (4) rising seawater temperatures and reduced water clarity limit the extent and diversity of rooted plants in the south and mid-Atlantic; (5) latitudinal changes in tidal regimes result in greater aerial exposure in the north, magnifying latitudinal sea surface temperature changes; (6) ice cover intensifies to the north and (7) the Boston−Washington, DC megalopolis accentuates human signatures through eutrophication between 36.5°N and 42.6°N. Finally, we discuss potential shifts with climate change in these latitudinal patterns and processes.
The Very High Frequency (VHF) Data Exchange System (VDES) is a new radio communication system being developed by the international maritime community, with the principal objectives to safeguard existing Automatic Identification System (AIS) core functions and enhance maritime communication applications, based on robust, efficient and secure data transmission with wider bandwidth than the AIS. VDES is also being considered as a potential component of the R-mode concept, where the same signals used for communication are also used for ranging, thus mitigating the impact of disruptions to satellite positioning services. This paper establishes statistical performance bounds on the ranging precision of VDES R-mode, assuming an additive white Gaussian noise propagation channel. Modified Cramér-Rao bounds on the pseudorange estimation error are provided for all waveforms currently proposed for use in terrestrial VDES communications. These are then used to estimate the maximum usable ranges for AIS/VDES R-mode stations. The results show that, under the assumed channel conditions, all of the new VDES waveforms provide better ranging performance than the AIS waveform, with the best performance being achieved using the 100 kHz bandwidth terrestrial VDE waveforms.
Neurocognitive deficits are often seen as core features of schizophrenia, and as primary determinants of poor functioning. Yet, our clinical observations suggest that individuals who score within the impaired range on standardized tests can reliably perform better in complex real-world situations, especially when performance is embedded within a positive socio-affective context.
We analyzed literature on the influence of non-neurocognitive factors on test performance in order to clarify their contributions.
We identified seven non-neurocognitive factors that significantly contribute to neurocognitive test performance: avolition, dysfunctional attitudes, effort, stress, negative emotions, asociality, and disorganized symptoms. We then proposed an alternative model based on dysfunctional (e.g. defeatist) attitudes and their consequences for motivation and sustained task engagement. We demonstrated that these factors account for substantial variance in negative symptoms, neurocognitive test performance, and functional outcomes. We then demonstrated that recovery-oriented cognitive therapy – which is derived from this alternative model and primarily targets dysfunctional beliefs – has been successful in the treatment of low functioning individuals with schizophrenia.
The contributions of neurocognitive impairments to poor real-world functioning in people with schizophrenia may be overstated in the literature, and may even be limited relative to non-neurocognitive factors. We offer suggestions for further research to more precisely quantify the contributions of attitudinal/motivation v. neurocognitive factors in schizophrenia.
Our knowledge of the functions of the prefrontal cortex, often called executive, supervisory, or control, has been transformed over the past 50 years. After operationally defining terms for clarification, we review the impact of advances in functional, structural, and theoretical levels of understanding upon neuropsychological assessment practice as a means of identifying 11 principles/challenges relating to assessment of executive function. Three of these were already known 50 years ago, and 8 have been confirmed or emerged since. Key themes over this period have been the emergence of the use of naturalistic tests to address issues of “ecological validity”; discovery of the complexity of the frontal lobe control system; invention of new tests for clinical use; development of key theoretical frameworks that address the issue of the role of prefrontal cortex systems in the organization of human cognition; the move toward considering brain systems rather than brain regions; the advent of functional neuroimaging, and its emerging integration into clinical practice. Despite these huge advances, however, practicing neuropsychologists are still desperately in need of new ways of measuring executive function. We discuss pathways by which this might happen, including decoupling the two levels of explanation (information processing; brain structure) and integrating very recent technological advances into the neuropsychologist’s toolbox. (JINS, 2017, 23, 755–767)
Whether monozygotic (MZ) and dizygotic (DZ) twins differ from each other in a variety of phenotypes is important for genetic twin modeling and for inferences made from twin studies in general. We analyzed whether there were differences in individual, maternal and paternal education between MZ and DZ twins in a large pooled dataset. Information was gathered on individual education for 218,362 adult twins from 27 twin cohorts (53% females; 39% MZ twins), and on maternal and paternal education for 147,315 and 143,056 twins respectively, from 28 twin cohorts (52% females; 38% MZ twins). Together, we had information on individual or parental education from 42 twin cohorts representing 19 countries. The original education classifications were transformed to education years and analyzed using linear regression models. Overall, MZ males had 0.26 (95% CI [0.21, 0.31]) years and MZ females 0.17 (95% CI [0.12, 0.21]) years longer education than DZ twins. The zygosity difference became smaller in more recent birth cohorts for both males and females. Parental education was somewhat longer for fathers of DZ twins in cohorts born in 1990–1999 (0.16 years, 95% CI [0.08, 0.25]) and 2000 or later (0.11 years, 95% CI [0.00, 0.22]), compared with fathers of MZ twins. The results show that the years of both individual and parental education are largely similar in MZ and DZ twins. We suggest that the socio-economic differences between MZ and DZ twins are so small that inferences based upon genetic modeling of twin data are not affected.
Because polarization encodes geometrical information about unresolved scattering regions, it provides a unique tool for analyzing the 3-D structures of supernovae (SNe) and their surroundings. SNe of all types exhibit time-dependent spectropolarimetric signatures produced primarily by electron scattering. These signatures reveal physical phenomena such as complex velocity structures, changing illumination patterns, and asymmetric morphologies within the ejecta and surrounding material. Interpreting changes in polarization over time yields unprecedentedly detailed information about supernovae, their progenitors, and their evolution.
Begun in 2012, the SNSPOL Project continues to amass the largest database of time-dependent spectropolarimetric data on SNe. I present an overview of the project and its recent results. In the future, combining such data with interpretive radiative transfer models will further constrain explosion mechanisms and processes that shape SN ejecta, uncover new relationships among SN types, and probe the properties of progenitor winds and circumstellar material.
A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.
V. Michelle Silvera, Staff Pediatric Neuroradiologist at Boston Children’s Hospital and Assistant Professor of Radiology at Harvard Medical School, Boston, Massachusetts, USA,
P. Ellen Grant, Director, Center on Fetal-Neonatal Neuroimaging and Developmental Science Center, Boston Children’s Hospital and Associate Professor of Radiology at Harvard Medical School, Boston, Massachusetts, USA,
Gary L. Hedlund, Chief of Neuroimaging at the Primary Children’s Medical Center and Adjunct Professor of Radiology at the University of Utah, Salt Lake City, Utah, USA,
Paul K. Kleinman, Department of Radiology, Boston Children’s Hospital, and Harvard Medical School, Boston, Massachusetts, USA
How and when to image the head in infants and children with suspected abusive head trauma (AHT) has become more complex with the increasing widespread availability of robust and elegant imaging technologies. These complex decisions are generally individualized based on available resources and expertise. The evidence base is modest with respect to the comparative diagnostic performance of the various neuroimaging modalities or magnetic resonance imaging (MRI) sequences in this specific context (1–5). Based on the available literature and the expertise of a panel of experts, the American College of Radiology (ACR) has put forth “Appropriateness Criteria” for imaging AHT and the organization periodically updates their recommendations in light of new data (6, 7). The goal of this chapter is to provide guidance to imaging departments that reflects the authors’ experience in light of current knowledge. Imaging strategies with respect to the skull, scalp, and subscalp have been covered in Chapter 17 – this discussion will focus on the approach to imaging the intracranial alterations described in Chapters 18 and 19. Craniocervical junction and spinal imaging strategies are addressed in Chapter 21.
Sonography is a valuable imaging tool used to assess children with suspected AHT. The anterior and posterior fontanels and squamosal portions of the temporal bones (transmastoid) serve as natural acoustic windows for cranial sonography in infants up to six months of age. Cranial sonography is a low-cost, noninvasive modality that can be performed at the bedside without sedation, and is particularly useful in evaluating children with severe AHT in the intensive care unit who are too unstable for transport to the radiology department and prolonged imaging in the MRI suite. This modality allows for prompt assessment of hydrocephalus, some subdural hematomas (SDHs), parenchymal abnormalities, and mass effect; and can detect small white matter lacerations (contusional tears) – lesions that may go undetected on head computed tomography (CT) and are considered highly suggestive of inflicted injury (8). Color and spectral Doppler analysis provide useful information with regard to cerebral blood flow and readily detect occlusive thrombosis of the superior sagittal venous sinus.
For over 100 years, the genetics of human anthropometric traits has attracted scientific interest. In particular, height and body mass index (BMI, calculated as kg/m2) have been under intensive genetic research. However, it is still largely unknown whether and how heritability estimates vary between human populations. Opportunities to address this question have increased recently because of the establishment of many new twin cohorts and the increasing accumulation of data in established twin cohorts. We started a new research project to analyze systematically (1) the variation of heritability estimates of height, BMI and their trajectories over the life course between birth cohorts, ethnicities and countries, and (2) to study the effects of birth-related factors, education and smoking on these anthropometric traits and whether these effects vary between twin cohorts. We identified 67 twin projects, including both monozygotic (MZ) and dizygotic (DZ) twins, using various sources. We asked for individual level data on height and weight including repeated measurements, birth related traits, background variables, education and smoking. By the end of 2014, 48 projects participated. Together, we have 893,458 height and weight measures (52% females) from 434,723 twin individuals, including 201,192 complete twin pairs (40% monozygotic, 40% same-sex dizygotic and 20% opposite-sex dizygotic) representing 22 countries. This project demonstrates that large-scale international twin studies are feasible and can promote the use of existing data for novel research purposes.
John Buchan, known principally for a series of espionage thrillers, is also the author of a large number of supernatural stories. His attraction to the genre, while indicating his eclectic interests, was both aesthetic and pragmatic. From the point of view of style, supernatural fiction contains the same essential ingredients as his ‘shockers’: excitement, mystery, suspense. Secondly, Buchan ‘wrote to be read’, and in his day, supernatural stories habitually drew a large audience. Modern ignorance of Buchan's contribution to this genre may be the result of the popularity of his other books: the nearest he came to a collection of supernatural stories was The Watcher by the Threshold (1902), but this book has ‘constantly been overshadowed by his other work’. While novels like Prester John (1910), The Dancing Floor (1926), Witch Wood (1927) and The Gap in the Curtain (1932) contain supernatural elements, Buchan's most consistent work in the genre is to be found in his short fiction. He wrote around twenty supernatural short stories, from the 1890s to the 1930s, proving that he had ‘an abiding interest in the supernatural’. But because the stories appeared over many years and in various publications, they have not been considered as a contained body of work worthy of serious study.
Buchan's supernatural stories have been included in anthologies, but they have only recently been collected in single-author volumes. To date (to the best of my knowledge), five such collections have appeared. Many of the selections are confusing, however, because a number of the stories have no supernatural content. This reflects the difficulties some editors have in defining the supernatural, a difficulty compounded by the fact that Buchan's stories are variously presented as examples of supernatural, horror, and of fantasy fiction, categories which many specialists working in the field regard as mutually exclusive. Defining the term ‘supernatural’ as it applies to literature is, in fact, a doomed enterprise, for the supernatural resists precise definition.
We review the present state of the understanding and application of high temperature superconductor materials ranging from attempts to clarify pairing mechanisms on the energy scale of a few milli-electron-volts to their use to embody terra-kwh continental wide deployment within the electricity enterprise. Examples include the use of density functional theory to study the relative roles of spin-fluctuation and/or lattice vibration induced Cooper pairing to modelling the incorporation of long distance HTSC transmission cables within the same natural gas pipeline rights-of-way infrastructure now emerging worldwide.
Social and psychological interventions are often complex. Understanding randomised controlled trials (RCTs) of these complex interventions requires a detailed description of the interventions tested and the methods used to evaluate them. However, RCT reports often omit, or inadequately report, this information. Incomplete and inaccurate reporting hinders the optimal use of research, wastes resources and fails to meet ethical obligations to research participants and consumers. In this paper, we explain how reporting guidelines have improved the quality of reports in medicine, and describe the ongoing development of a new reporting guideline for RCTs: CONSORT-SPI (an extension for social and psychological interventions). We invite readers to participate in the project by visiting our website, in order to help us reach the best-informed consensus on these guidelines (http://tinyurl.com/CONSORT-study).