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Producers often contemplate expanding or contracting production to take advantage of cyclical cattle price trends. This study quantifies profitability and risk implications of (1) constant herd size, (2) dollar cost averaging, and (3) price signal-based, anticipatory countercyclical expansion/contraction strategies. Weather simulation on forages with different calving season and land use intensity showed fall calving herds with added hay sales from greater fertilizer use and the countercyclical herd size management strategy to be most profitable regardless of weather or time period analyzed. Income risk was comparable to least fertilizer use. Overall, holding herd size constant led to little regret.
A national need is to prepare for and respond to accidental or intentional disasters categorized as chemical, biological, radiological, nuclear, or explosive (CBRNE). These incidents require specific subject-matter expertise, yet have commonalities. We identify 7 core elements comprising CBRNE science that require integration for effective preparedness planning and public health and medical response and recovery. These core elements are (1) basic and clinical sciences, (2) modeling and systems management, (3) planning, (4) response and incident management, (5) recovery and resilience, (6) lessons learned, and (7) continuous improvement. A key feature is the ability of relevant subject matter experts to integrate information into response operations. We propose the CBRNE medical operations science support expert as a professional who (1) understands that CBRNE incidents require an integrated systems approach, (2) understands the key functions and contributions of CBRNE science practitioners, (3) helps direct strategic and tactical CBRNE planning and responses through first-hand experience, and (4) provides advice to senior decision-makers managing response activities. Recognition of both CBRNE science as a distinct competency and the establishment of the CBRNE medical operations science support expert informs the public of the enormous progress made, broadcasts opportunities for new talent, and enhances the sophistication and analytic expertise of senior managers planning for and responding to CBRNE incidents.
Surface debris covers much of the western portion of the McMurdo Ice Shelf and has a strong influence on the local surface albedo and energy balance. Differential ablation between debris-covered and debris-free areas creates an unusual heterogeneous surface of topographically low, high-ablation, and topographically raised (‘pedestalled’), low-ablation areas. Analysis of Landsat and MODIS satellite imagery from 1999 to 2018, alongside field observations from the 2016/2017 austral summer, shows that pedestalled relict lakes (‘pedestals’) form when an active surface meltwater lake that develops in the summer, freezes-over in winter, resulting in the lake-bottom debris being masked by a high-albedo, superimposed, ice surface. If this ice surface fails to melt during a subsequent melt season, it experiences reduced surface ablation relative to the surrounding debris-covered areas of the ice shelf. We propose that this differential ablation, and resultant hydrostatic and flexural readjustments of the ice shelf, causes the former supraglacial lake surface to become increasingly pedestalled above the lower topography of the surrounding ice shelf. Consequently, meltwater streams cannot flow onto these pedestalled features, and instead divert around them. We suggest that the development of pedestals has a significant influence on the surface-energy balance, hydrology and flexure of the ice shelf.
Sampling is a necessary part of the chemical analysis of particulate matter where the objective is to characterize bulk properties since it is usually undesirable or impossible to test an entire lot. The sample must be a miniature replica of the bulk material at least in respect to those features being tested. In other words, the sample must be representative to permit extrapolation from the sample to the bulk.
There is error associated with sampling particulate material, but this sampling error is only one component of the total error associated with an analytical result. Sample preparation and determination of the property being tested are two other major sources of error, These three errors combine as the squares of their standard deviations, i.e., their variances, to produce the total analytical error. Very often, sampling error is the largest of the three and, therefore, contributes a disproportionately large share to the total error.
Introduction: The purpose of this study is to determine if the introduction of a pre-arrival and pre-departure Trauma Checklist as a cognitive aid, coupled with an educational session, will improve clinical performance in a simulated environment. The Trauma Checklist was developed in response to a quality assurance review of high-acuity trauma activations. It focuses on pre-arrival preparation and a pre-departure review prior to patient transfer to diagnostic imaging or the operating room. We conducted a pilot, randomized control trial assessing the impact of the Trauma Checklist on time to critical interventions on a simulated pediatric patient by multidisciplinary teams. Methods: Emergency department teams composed of 2 physicians, 2 nurses and 2 confederate actors were enrolled in our study. In the intervention arm, participants watched a 10-minute educational video modelling the use of the trauma checklist prior to their simulation scenario and were provided a copy of the checklist. Teams participated in a standardized simulation scenario caring for a severely injured adolescent patient with hemorrhagic shock, respiratory failure and increased intracranial pressure. Our primary outcome of interest was time measurement to initiation of key clinical interventions, including intubation, first blood product administration, massive transfusion protocol activation, initiation of hyperosmolar therapy and others. Secondary outcome measures included a Trauma Task Performance score and checklist completion scores. Results: We enrolled 14 multidisciplinary teams (n=56 participants) into our study. There was a statistically significant decrease in median time to initiation of hyperosmolar therapy by teams in the intervention arm compared to the control arm (581 seconds, [509-680] vs. 884 seconds, [588-1144], p=0.03). Time to initiation of other clinical interventions was not statistically significant. There was a trend to higher Trauma Task Performance scores in the intervention group however this did not reach statistical significant (p=0.09). Pre-arrival and pre-departure checklist scores were higher in the intervention group (9.0 [9.0-10.0] vs. 7.0 [6.0-8.0], p=0.17 and 12.0 [11.5-12.0] vs. 7.5 [6.0-8.5], p=0.01). Conclusion: Teams using the Trauma Checklist did not have decreased time to initiation of key clinical interventions except in initiating hyperosmolar therapy. Teams in the intervention arm had statistically significantly higher pre-arrival and pre-departure scores, with a trend to higher Trauma Task Performance scores. Our study was a pilot and recruitment did not achieve the anticipated sample size, thus underpowered. The impact of this checklist should be studied outside tertiary trauma centres, particularly in trainees and community emergency providers, to assess for benefit and further generalizability.
Although dementia has been described in ancient texts over many centuries (e.g., “Be kind to your father, even if his mind fail him.” – Old Testament: Sirach 3:12), our knowledge of its underlying causes is little more than a century old. Alzheimer published his now famous case study only 110 years ago, and our modern understanding of the disease that bears his name, and its neuropsychological consequences, really only began to accelerate in the 1980s. Since then we have witnessed an explosion of basic and translational research into the causes, characterizations, and possible treatments for Alzheimer’s disease (AD) and other dementias. We review this lineage of work beginning with Alzheimer’s own writings and drawings, then jump to the modern era beginning in the 1970s and early 1980s and provide a sampling of neuropsychological and other contextual work from each ensuing decade. During the 1980s our field began its foundational studies of profiling the neuropsychological deficits associated with AD and its differentiation from other dementias (e.g., cortical vs. subcortical dementias). The 1990s continued these efforts and began to identify the specific cognitive mechanisms affected by various neuropathologic substrates. The 2000s ushered in a focus on the study of prodromal stages of neurodegenerative disease before the full-blown dementia syndrome (i.e., mild cognitive impairment). The current decade has seen the rise of imaging and other biomarkers to characterize preclinical disease before the development of significant cognitive decline. Finally, we suggest future directions and predictions for dementia-related research and potential therapeutic interventions. (JINS, 2017, 23, 818–831)
This paper highlights major developments over the past two to three decades in the neuropsychology of movement and its disorders. We focus on studies in healthy individuals and patients, which have identified cognitive contributions to movement control and animal work that has delineated the neural circuitry that makes these interactions possible. We cover advances in three major areas: (1) the neuroanatomical aspects of the “motor” system with an emphasis on multiple parallel circuits that include cortical, corticostriate, and corticocerebellar connections; (2) behavioral paradigms that have enabled an appreciation of the cognitive influences on the preparation and execution of movement; and (3) hemispheric differences (exemplified by limb praxis, motor sequencing, and motor learning). Finally, we discuss the clinical implications of this work, and make suggestions for future research in this area. (JINS, 2017, 23, 768–777)
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.
Identifying the transmission sources and reservoirs of Streptococcus pneumoniae (SP) is a long-standing question for pneumococcal epidemiology, transmission dynamics, and vaccine policy. Here we use serotype to identify SP transmission and examine acquisitions (in the same household, local community, and county, or of unidentified origin) in a longitudinal cohort of children and adults from the Navajo Nation and the White Mountain Apache American Indian Tribes. We found that adults acquire SP relatively more in the household than other age groups, and children 2–8 years old typically acquire in their own or surrounding communities. Age-specific transmission probability matrices show that transmissions within household were mostly seen from older to younger siblings. Outside the household, children most often transmit to other children in the same age group, showing age-assortative mixing behavior. We find toddlers and older children to be most involved in SP transmission and acquisition, indicating their role as key drivers of SP epidemiology. Although infants have high carriage prevalence, they do not play a central role in transmission of SP compared with toddlers and older children. Our results are relevant to inform alternative pneumococcal conjugate vaccine dosing strategies and analytic efforts to inform optimization of vaccine programs, as well as assessing the transmission dynamics of pathogens transmitted by close contact in general.
On 2 March 2016, several small en échelon tabular icebergs calved from the seaward front of the McMurdo Ice Shelf, and a previously inactive rift widened and propagated by ~3 km, ~25% of its previous length, setting the stage for the future calving of a ~14 km2 iceberg. Within 24 h of these events, all remaining land-fast sea ice that had been stabilizing the ice shelf broke-up. The events were witnessed by time-lapse cameras at nearby Scott Base, and put into context using nearby seismic and automatic weather station data, satellite imagery and subsequent ground observation. Although the exact trigger of calving and rifting cannot be identified definitively, seismic records reveal superimposed sets of both long-period (>10 s) sea swell propagating into McMurdo Sound from storm sources beyond Antarctica, and high-energy, locally-sourced, short-period (<10 s) sea swell, in the 4 days before the fast ice break-up and associated ice-shelf calving and rifting. This suggests that sea swell should be studied further as a proximal cause of ice-shelf calving and rifting; if proven, it suggests that ice-shelf stability is tele-connected with far-field storm conditions at lower latitudes, adding a global dimension to the physics of ice-shelf break-up.
Negative symptoms significantly contribute to disability and lack of community participation for low functioning individuals with schizophrenia. Cognitive therapy has been shown to improve negative symptoms and functional outcome in this population. Elucidation of the mechanisms of the therapy would lead to a better understanding of negative symptoms and the development of more effective interventions to promote recovery. The objective of this study was to determine (1) whether guided success at a card-sorting task will produce improvement in defeatist beliefs, positive beliefs about the self, mood, and card-sorting performance, and (2) whether these changes in beliefs and mood predict improvements in unguided card-sorting.
Individuals with schizophrenia having prominent negative symptoms and impaired neurocognitive performance (N = 35) were randomized to guided success (n = 19) or a control (n = 16) condition.
Controlling for baseline performance, the experimental group performed significantly better, endorsed defeatist beliefs to a lesser degree, reported greater positive self-concept, and reported better mood than the control condition immediately after the experimental session. A composite index of change in defeatist beliefs, self-concept, and mood was significantly correlated with improvements in card-sorting.
This analogue study supports the rationale of cognitive therapy and provides a general therapeutic model in which experiential interventions that produce success have a significant immediate effect on a behavioral task, mediated by changes in beliefs and mood. The rapid improvement is a promising indicator of the responsiveness of this population, often regarded as recalcitrant, to cognitively-targeted behavioral interventions.
Clinical depression affects approximately 15% of community-dwelling older adults, of which half of these cases present in later life. Falls and depressive symptoms are thought to co-exist, while physical activity may protect an older adult from developing depressive symptoms. This study investigates the temporal relationships between depressive symptoms, falls, and participation in physical activities amongst older adults recently discharged following extended hospitalization.
A prospective cohort study in which 311 older adults surveyed prior to hospital discharge were assessed monthly post-discharge for six months. N = 218 completed the six-month follow-up. Participants were recruited from hospitals in Melbourne, Australia. The survey instrument used was designed based on Fiske's behavioral model depicting onset and maintenance of depression. The baseline survey collected data on self-reported falls, physical activity levels, and depressive symptoms. The monthly follow-up surveys repeated measurement of these outcomes.
At any assessment point, falls were positively associated with depressive symptoms; depressive symptoms were negatively associated with physical activity levels; and, physical activity levels were negatively associated with falls. When compared with data in the subsequent assessment point, depressive symptoms were positively associated with falls reported over the next month (unadjusted OR: 1.20 (1.12, 1.28)), and physical activity levels were negatively associated with falls reported over the next month (unadjusted OR: 0.97 (0.96, 0.99) household and recreational), both indicating a temporal relationship.
Falls, physical activity, and depressive symptoms were inter-associated, and depressive symptoms and low physical activity levels preceded falls. Clear strategies for management of these interconnected problems remain elusive.
We estimate the blank carbon mass over the course of a typical Ramped PyrOx (RPO) analysis (150–1000°C; 5°C×min–1) to be (3.7±0.6) μg C with an Fm value of 0.555±0.042 and a δ13C value of (–29.0±0.1) ‰ VPDB. Additionally, we provide equations for RPO Fm and δ13C blank corrections, including associated error propagation. By comparing RPO mass-weighted mean and independently measured bulk δ13C values for a compilation of environmental samples and standard reference materials (SRMs), we observe a small yet consistent 13C depletion within the RPO instrument (mean–bulk: μ=–0.8‰; ±1σ=0.9‰; n=66). In contrast, because they are fractionation-corrected by definition, mass-weighted mean Fm values accurately match bulk measurements (mean–bulk: μ=0.005; ±1σ=0.014; n=36). Lastly, we show there exists no significant intra-sample δ13C variability across carbonate SRM peaks, indicating minimal mass-dependent kinetic isotope fractionation during RPO analysis. These data are best explained by a difference in activation energy between 13C- and 12C-containing compounds (13–12∆E) of 0.3–1.8 J×mol–1, indicating that blank and mass-balance corrected RPO δ13C values accurately retain carbon source isotope signals to within 1–2‰.
Evidence for a relationship between neurocognition and functional outcome in important areas of community living is robust in serious mental illness research. Dysfunctional attitudes (defeatist performance beliefs and asocial beliefs) have been identified as intervening variables in this causal chain. This study seeks to expand upon previous research by longitudinally testing the link between neurocognition and community participation (i.e. time in community-based activity) through dysfunctional attitudes and motivation.
Adult outpatients with serious mental illness (N = 175) participated, completing follow-up assessments approximately 6 months after initial assessment. Path analysis tested relationships between baseline neurocognition, emotion perception, functional skills, dysfunctional attitudes, motivation, and outcome (i.e. community participation) at baseline and follow-up.
Path models demonstrated two pathways to community participation. The first linked neurocognition and community participation through functional skills, defeatist performance beliefs, and motivation. A second pathway linked asocial beliefs and community participation, via a direct path passing through motivation. Model fit was excellent for models predicting overall community participation at baseline and, importantly, at follow-up.
The existence of multiple pathways to community participation in a longitudinal model supports the utility of multi-modal interventions for serious mental illness (i.e. treatment packages that build upon individuals’ strengths while addressing the array of obstacles to recovery) that feature dysfunctional attitudes and motivation as treatment targets.
This paper seeks to establish good practice in setting inputs for operational risk models for banks, insurers and other financial service firms. It reviews Basel, Solvency II and other regulatory requirements as well as publicly available literature on operational risk modelling. It recommends a combination of historic loss data and scenario analysis for modelling of individual risks, setting out issues with these data, and outlining good practice for loss data collection and scenario analysis. It recommends the use of expert judgement for setting correlations, and addresses information requirements for risk mitigation allowances and capital allocation, before briefly covering Bayesian network methods for modelling operational risks.