To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Hyperventilation during cardiopulmonary resuscitation (CPR) negatively affects cardiopulmonary physiology. Compression-adjusted ventilations (CAVs) may allow providers to deliver ventilation rates more consistently than conventional ventilations (CVs). This study sought to compare ventilation rates between these two methods during simulated cardiac arrest.
That CAV will not result in different rates than CV in simulated CPR with metronome-guided compressions.
Volunteer Basic Life Support (BLS)-trained providers delivered bag-valve-mask (BVM) ventilations during simulated CPR with metronome-guided compressions at 100 beats/minute. For the first 4-minute interval, volunteers delivered CV. Volunteers were then instructed on how to perform CAV by delivering one breath, counting 12 compressions, and then delivering a subsequent breath. They then performed CAV for the second 4-minute interval. Ventilation rates were manually recorded. Minute-by-minute ventilation rates were compared between the techniques.
A total of 23 volunteers were enrolled with a median age of 36 years old and with a median of 14 years of experience. Median ventilation rates were consistently higher in the CV group versus the CAV group across all 1-minute segments: 13 vs 9, 12 vs 8, 12 vs 8, and 12 vs 8 for minutes one through four, respectively (P <.01, all). Hyperventilation (>10 breaths per minute) occurred 64% of the time intervals with CV versus one percent with CAV (P <.01). The proportion of time which hyperventilation occurred was also consistently higher in the CV group versus the CAV group across all 1-minute segments: 78% vs 4%, 61% vs 0%, 57% vs 0%, and 61% vs 0% for minutes one through four, respectively (P <.01, all).
In this simulated model of cardiac arrest, CAV had more accurate ventilation rates and fewer episodes of hyperventilation compared with CV.
Nikolla DA, Kramer BJ, Carlson JN. A cross-over trial comparing conventional to compression-adjusted ventilations with metronome-guided compressions. Prehosp Disaster Med. 2019;34(2):220–223
Much of the US public acquires political information socially. However, the consequences of acquiring information from others instead of the media are under-explored. I conduct a “telephone-game” experiment to examine how information changes as it flows from official reports to news outlets to other people, finding that social information is empirically different from news articles. In a second experiment on a nationally representative sample, I randomly assign participants to read a news article or a social message about that article generated in Study 1. Participants exposed to social information learned significantly less than participants who were exposed to the news article. However, individuals exposed to information from someone who is like-minded and knowledgeable learned the same objective facts as those who received information from the media. Although participants learned the same factual information from these ideal informants as they did from the media, they had different subjective evaluations.
Little is known about the effect of natural disasters on children's neural development. Additionally, despite evidence that stress and parenting may both influence the development of neural systems underlying reward and threat processing, few studies have brought together these areas of research. The current investigation examined the effect of parenting styles and hurricane-related stress on the development of neural reactivity to reward and threat in children. Approximately 8 months before and 9 months after Hurricane Sandy, 74 children experiencing high and low levels of hurricane-related stress completed tasks that elicited the reward positivity and error-related negativity, event-related potentials indexing sensitivity to reward and threat, respectively. At the post-Hurricane assessment, children completed a self-report questionnaire to measure promotion- and prevention-focused parenting styles. Among children exposed to high levels of hurricane-related stress, lower levels of promotion-focused, but not prevention-focused, parenting were associated with a reduced post-Sandy reward positivity. In addition, in children with high stress exposure, greater prevention-focused, but not promotion-focused, parenting was associated with a larger error-related negativity after Hurricane Sandy. These findings highlight the need to consider contextual variables such as parenting when examining how exposure to stress alters the development of neural reactivity to reward and threat in children.
Many preschool-age children meet criteria for psychiatric disorders, and rates approach those observed in later childhood and adolescence. However, there is a paucity of longitudinal research examining the outcomes of preschool diagnoses.
Families with a 3-year-old child (N = 559) were recruited from the community. Primary caregivers were interviewed using the Preschool Age Psychiatric Assessment when children were 3 years old (n = 541), and, along with children, using the Schedule for Affective Disorders and Schizophrenia for School-Age Children Present and Lifetime Version when children were 9 and 12 years old.
Rates of disruptive behavior disorders (DBD) decreased from preschool to middle childhood and early adolescence, whereas rates of attention-deficit/hyperactivity disorder (ADHD) increased. Rates of any psychiatric disorder and depression increased from preschool to early adolescence only. Preschoolers with a diagnosis were over twice as likely to have a diagnosis during later periods. Homotypic continuity was present for anxiety disorders from preschool to middle childhood, for ADHD from preschool to early adolescence, and for DBD through both later time points. There was heterotypic continuity between preschool anxiety and early adolescent depression, and between preschool ADHD and early adolescent DBD. Dimensional symptom scores showed homotypic continuity for all diagnostic categories and showed a number of heterotypic associations as well.
Results provide moderate support for the predictive validity of psychiatric disorders in preschoolers. Psychopathology in preschool is a significant risk factor for future psychiatric disorders during middle childhood and early adolescence.
With European Laser Facilities such as the Extreme Light Infrastructure (ELI) and the Helmholtz International Beamline for Extreme Fields (HIBEF) scheduled to come online within the next couple of years, General Atomics, as a major supplier of targets and target components for the High Energy Density Physics community in the United States, is gearing up to meet their demand for large numbers of low cost targets. Using the production of a subassembly for the National Ignition Facility’s fusion targets as an example, we demonstrate that through automation of assembly tasks, the design of targets and their experimental setup can be fairly complex while keeping the assembly time and cost as a minimum. A six-axis Mitsubishi robot is used in combination with vision feedback and a force–torque sensor to assemble target subassemblies of different scales and designs with minimal change of tooling, allowing for design flexibility and short assembly setup times. Implementing automated measurement routines on a Nikon NEXIV microscope further reduces the effort required for target metrology, while electronic data collection and transfer complete a streamlined target production operation that can be adapted to a large variety of target designs.
There is increasing interest among developmental psychopathologists in broad transdiagnostic factors that give rise to a wide array of clinical presentations (multifinality), but little is known about how these processes lead to particular psychopathological manifestations over the course of development. We examined whether individual differences in the error-related negativity (ΔERN), a neural indicator of error monitoring, predicts whether early persistent irritability, a prototypical transdiagnostic construct, is associated with later internalizing versus externalizing outcomes. When children were 3 years old, mothers were interviewed about children's persistent irritability and completed questionnaires about their children's psychopathology. Three years later, EEG was recorded while children performed a go/no-go task to measure the ΔERN. When children were approximately 9 years old, mothers again completed questionnaires about their children's psychopathology. The results indicated that among children who were persistently irritable at age 3, an enhanced or more negative ΔERN at age 6 predicted the development of internalizing symptoms at age 9, whereas a blunted or smaller ΔERN at age 6 predicted the development of externalizing symptoms. Our results suggest that variation in error monitoring predicts, and may even shape, the expression of persistent irritability and differentiates developmental trajectories from preschool persistent irritability to internalizing versus externalizing outcomes in middle to late childhood.
Metaperceptions, or beliefs about how other people perceive the self, are the implicit maps people use to navigate complex social environments. Are metaperceptions accurate? The answer to this question is complex and depends on several factors, such as how insight is measured, the attribute in question, and the social context. We first review several ways in which the accuracy of metaperceptions is typically conceptualized and measured. We then summarize for which attributes (e.g., intelligent, likeable) and in which contexts (e.g., among friends or coworkers) metaperceptions are accurate as well as for whom (e.g., personality traits, status) and in which situations. Next, we consider the process of metaperception and which sources of information lead people to form accurate beliefs about how others perceive them. Finally, we discuss future directions that may shed more light on when people know how others experience them and how to potentially improve this type of insight.
Little is known about the predictive validity of disruptive mood dysregulation disorder (DMDD). This longitudinal, community-based study examined associations of DMDD at the age of 6 years with psychiatric disorders, functional impairment, peer functioning and service use at the age of 9 years.
A total of 473 children were assessed at the ages of 6 and 9 years. Child psychopathology and functional impairment were assessed at the age of 6 years with the Preschool Age Psychiatric Assessment with parents and at the age of 9 years with the Kiddie-Schedule of Affective Disorders and Schizophrenia (K-SADS) with parents and children. At the age of 9 years, mothers, fathers and youth completed the Child Depression Inventory (CDI) and the Screen for Child Anxiety Related Disorders, and teachers and K-SADS interviewers completed measures of peer functioning. Significant demographic covariates were included in all models.
DMDD at the age of 6 years predicted a current diagnosis of DMDD at the age of 9 years. DMDD at the age of 6 years also predicted current and lifetime depressive disorder and attention-deficit/hyperactivity disorder (ADHD) at the age of 9 years, after controlling for all age 6 years psychiatric disorders. In addition, DMDD predicted depressive, ADHD and disruptive behavior disorder symptoms on the K-SADS, and maternal and paternal reports of depressive symptoms on the CDI, after controlling for the corresponding symptom scale at the age of 6 years. Last, DMDD at the age of 6 years predicted greater functional impairment, peer problems and educational support service use at the age of 9 years, after controlling for all psychiatric disorders at the age of 6 years.
Children with DMDD are at high risk for impaired functioning across childhood, and this risk is not accounted for by co-morbid conditions.
According to diathesis–stress models, personality traits, such as negative emotionality (NE) and positive emotionality (PE), may moderate the effects of stressors on the development of depression. However, relatively little empirical research has directly examined whether NE and PE act as diatheses in the presence of stressful life events, and no research has examined whether they moderate the effect of disaster exposure on depressive symptoms. Hurricane Sandy, the second costliest hurricane in US history, offers a unique opportunity to address these gaps.
A total of 318 women completed measures of NE and PE 5 years prior to Hurricane Sandy. They were also assessed for lifetime depressive disorders on two occasions, the latter occurring an average of 1 year before the hurricane. Approximately 8 weeks after the disaster (mean = 8.40, s.d. = 1.48 weeks), participants completed a hurricane stress exposure questionnaire and a measure of current depressive symptoms.
Adjusting for lifetime history of depressive disorders, higher levels of stress from Hurricane Sandy predicted elevated levels of depressive symptoms, but only in participants with high levels of NE or low levels of PE.
These findings support the role of personality in the development of depression and suggest that personality traits can be useful in identifying those most vulnerable to major stressors, including natural disasters.
Pulmonary aspiration of gastric contents occurs 20 to 30% of the time during cardiopulmonary resuscitation (CPR) of cardiac arrest due to loss of protective airway reflexes, pressure changes generated during CPR, and positive pressure ventilation (PPV). Although the American Heart Association has recommended the laryngeal mask airway (LMA) as an acceptable alternative airway for use by emergency medical service personnel, concerns over the capacity of the device to protect from pulmonary aspiration remain.We sought to determine the occurrence of aspiration after LMA placement, CPR, and PPV.
We inserted a size 4 LMA, modified so that a vacuum catheter could be advanced past the LMA diaphragm, into the hypopharynx of 16 consecutive postexperimental mixed-breed domestic swine. Fifteen millilitres of heparinized blood was instilled into the oropharynx. Chest compressions were performed for 60 seconds with asynchronous ventilation via a mechanical ventilator. We then suctioned through the LMA for 1 minute. The catheter was removed and inspected for signs of blood. The LMA cuff was deflated, removed, and inspected for signs of blood.
None of 16 animals (95% CI 0-17%) had a positive test for the presence of blood in both the vacuum catheter and the intima of the LMA diaphragm.
In this swine model of regurgitation after LMA placement, there were no cases with evidence of blood beyond the seal created by the LMA cuff. Future studies are needed to determine the frequency of pulmonary aspiration after LMA placement during CPR and PPV in the clinical setting.
Despite the inclusion of disruptive mood dysregulation disorder (DMDD) in DSM-5, little empirical data exist on the disorder. We estimated rates, co-morbidity, correlates and early childhood predictors of DMDD in a community sample of 6-year-olds.
DMDD was assessed in 6-year-old children (n = 462) using a parent-reported structured clinical interview. Age 6 years correlates and age 3 years predictors were drawn from six domains: demographics; child psychopathology, functioning, and temperament; parental psychopathology; and the psychosocial environment.
The 3-month prevalence rate for DMDD was 8.2% (n = 38). DMDD occurred with an emotional or behavioral disorder in 60.5% of these children. At age 6 years, concurrent bivariate analyses revealed associations between DMDD and depression, oppositional defiant disorder, the Child Behavior Checklist – Dysregulation Profile, functional impairment, poorer peer functioning, child temperament (higher surgency and negative emotional intensity and lower effortful control), and lower parental support and marital satisfaction. The age 3 years predictors of DMDD at age 6 years included child attention deficit hyperactivity disorder, oppositional defiant disorder, the Child Behavior Checklist – Dysregulation Profile, poorer peer functioning, child temperament (higher child surgency and negative emotional intensity and lower effortful control), parental lifetime substance use disorder and higher parental hostility.
A number of children met DSM-5 criteria for DMDD, and the diagnosis was associated with numerous concurrent and predictive indicators of emotional and behavioral dysregulation and poor functioning.
Thermoelectric materials with stable mechanical and chemical properties at high temperature are required for power generation applications. For example, gas temperatures up to 1000°C are normally present in the waste stream of industrial processes and this can be used for electricity generation. There are few semiconductor materials that can operate effectively at these high temperatures. One solution may be the use of wide bandgap materials, and in particular GaN-based materials, which may offer a traditional semiconductor solution for high temperatures thermoelectric power generation. In particular, the ability to both grow GaN-based materials and fabricate them into devices is well understood if their thermoelectric properties are favorable. To investigate the possibility of using III-Nitride and its alloys for thermoelectric applications, we synthesized and characterized room temperature thermoelectric properties of metal organic chemical vapor deposition grown GaN and InGaN with different carrier concentrations and indium compositions. The promising value of Seebeck coefficients and power factors of Si-doped GaN and InGaN indicated that these materials are suitable for thermoelectric applications.
Grain boundary and crystallographic orientation information of an Al-foil with a columnar grain structure is characterized by Electron Backscattered Diffraction (EBSD) technique. The starting microstructure and grain boundary properties are implemented as an input for the three- dimensional grain growth simulation. In the computational model, minimization of the interface energy is the driving force for the grain boundary motion. The computed evolved microstructure is compared with the final experimental microstructure, after annealing at 550 °C. Good agreement is observed between the experimentally obtained microstructure and the simulated microstructure. The constitutive description of the grain boundary properties was based on a 1- parameter characterization of the variation in mobility with misorientation angle.
In a previous paper, we presented a general theoretical treatment of the effect of stress on defect diffusion in Si (M. S. Daw, W. Windl, N. N. Carlson, M. Laudon, and M. P. Masquelier, to be published in Phys. Rev. B). In this paper, we discuss the calculation of the parameters governing the stress dependence of the diffusivity, which are volume quantities, and present the fully anisotropic volume tensor for vacancy formation in Si.
A laser scanning system has been developed by the National Renewable Energy Laboratory for the rapid characterization of crystal defects in single- and poly-crystalline semiconductors. The scanning defect mapping system has been commercialized by Labsphere, Inc. as the PVScan 5000. In the unprocessed material, the system produces digital color maps of the spatial distributions of dislocations and grain boundaries simultaneously. After device fabrication, the PVScan 5000 is used to produce photoresponsivity maps of the light beam induced current (LBIC) on a photovoltaic device such as a solar cell or a photodetector. An additional feature is that it also measures the spatial distributions of optical reflectance, both specular and diffuse, which can be applied to the LBIC maps to determine the internal responsivity of the device. The internal responsivity is proportional to the minority carrier diffusion length of silicon devices. It may be possible, therefore, to determine the diffusion length for certain devices.
Thermal expansion mismatch causes serious problems in operating device reliability because of the various stresses imposed on the joint materials undergoing temperature changes. Silicon has a low expansion coefficient so strain buffers are often employed between the silicon and the outer metal covers with relatively high expansion coefficients. These buffers can be metals like molybdenum, ceramics like alumina, or a brush structure of copper, with soft solders at the joints. However, solders themselves have finite fatigue lives which can be estimated from material and dimensional data.
XANES (X-ray Absorption Near Edge Spectroscopy) has been employed to evaluate the efficacy of a process designed to encapsulate and reduce TcO4- in cement matrices, thereby immobilizing Tc. The oxidation state of Se following bioremediation of Se by bacteria has also been determined by XANES. The XANES measurements were performed at the Stanford Synchrotron Radiation Laboratory (SSRL) and the National Synchrotron Light Source (NSLS) at the respective K edges of Tc (21.0 keV) and Se (12.7 keV). Comparison of the XANES spectra of Tc in untreated cement to Tc in slag treated cement and to the chemical shifts of reference materials, shows that the oxidation state of Tc is the same in both cements. Thus, the addition of a reducing agent to the cement formulation does not significantly reduce the TcO4-. The common soil bacterium, Bacillus subtilis, is known to incorporate Se on or within the cell wall when exposed to a Se(IV) solution. The Se XANES spectra of B. subtilis, as well as bacillus isolated from selenium rich soil, show that the organisms reduce selenite to the red allotrope of elemental Se.