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.
Despite a recent increase in research on its sociopolitical implications, many questions regarding rap music’s influence on mass-level participation remain unanswered. We consider the possibility that “imagining a better world” (measured here as the degree to which young African Americans are critical of the music’s negative messages) can correlate with a desire to “build a better world” (operationalized as an individual’s level of political participation). Evidence from the Black Youth Project (BYP)’s Youth Culture Survey (Cohen 2005) demonstrates that rap critique exerts a conditional impact on non-voting forms of activism. Rap critique enhances heavy consumers’ civic engagement, but this relationship does not occur among Blacks who consume the music infrequently. By demonstrating rap’s politicizing power and contradicting certain criticisms of Hip Hop culture, our research celebrates the possibilities of Black youth and Black music.
Child maltreatment has been associated with various cumulative risk factors. However, little is known about the extent to which genetic and environmental factors contribute to individual differences between parents in perpetrating child maltreatment. To estimate the relative contribution of genetic and environmental factors to perpetrating maltreatment we used a parent-based extended family design. Child-reported perpetrated maltreatment was available for 556 parents (283 women) from 63 families. To explore reporter effects (i.e., child perspective on maltreatment), child reports were compared to multi-informant reports. Based on polygenic model analyses, most of the variance related to the perpetration of physical abuse and emotional neglect was explained by common environmental factors (physical abuse: c2 = 59%, SE = 12%, p = .006; emotional neglect: c2 = 47%, SE = 8%, p < .001) whereas genetic factors did not significantly contribute to the model. For perpetrated emotional abuse, in contrast, genetic factors did significantly contribute to perpetrated emotional abuse (h2 = 33%, SE = 8%, p < .001), whereas common environment factors did not. Multi-informant reports led to similar estimates of genetic and common environmental effects on all measures except for emotional abuse, where a multi-informant approach yielded higher estimates of the common environmental effects. Overall, estimates of unique environment, including measurement error, were lower using multi-informant reports. In conclusion, our findings suggest that genetic pathways play a significant role in perpetrating emotional abuse, while physical abuse and emotional neglect are transmitted primarily through common environmental factors. These findings imply that interventions may need to target different mechanisms dependings on maltreatment type.
The current study compared beef production, quality and fatty acid (FA) profiles of yearling steers fed a control diet containing 70 : 30 red clover silage (RCS) : barley-based concentrate, a diet containing 11% sunflower seed (SS) substituted for barley, and diets containing SS with15% or 30% wheat dried distillers’ grain with solubles (DDGS). Additions of DDGS were balanced by reductions in RCS and SS to maintain crude fat levels in diets. A total of two pens of eight animals were fed per diet for an average period of 208 days. Relative to the control diet, feeding the SS diet increased (P<0.05) average daily gain, final live weight and proportions of total n-6 FA, non-conjugated 18:2 biohydrogenation products (i.e. atypical dienes) with the first double bond at carbon 8 or 9 from the carboxyl end, conjugated linoleic acid isomers with the first double bond from carbon 7 to 10 from the carboxyl end, t-18:1 isomers, and reduced (P<0.05) the proportions of total n-3 FA, conjugated linolenic acids, branched-chain FA, odd-chain FA and 16:0. Feeding DDGS-15 and DDGS-30 diets v. the SS diet further increased (P<0.05) average daily gains, final live weight, carcass weight, hot dressing percentage, fat thickness, rib-eye muscle area, and improved instrumental and sensory panel meat tenderness. However, in general feeding DGGS-15 or DDGS-30 diets did not change FA proportions relative to feeding the SS diet. Overall, adding SS to a RCS-based diet enhanced muscle proportions of 18:2n-6 biohydrogenation products, and further substitutions of DDGS in the diet improved beef production, and quality while maintaining proportions of potentially functional bioactive FA including vaccenic and rumenic acids.
The present study examined the impact of children's maltreatment experiences on the emergence of externalizing problem presentations among children during different developmental periods. The sample included 788 youth and their caregivers who participated in a multisite, prospective study of youth at-risk for maltreatment. Externalizing problems were assessed at ages 4, 8, and 12, and symptoms and diagnoses of attention-deficit/hyperactivity disorder, oppositional defiant disorder, and conduct disorder were assessed at age 14, during interviews with youth and caregivers. Information about maltreatment allegations was coded from official records. Latent transition analysis identified three groups of youth with similar presentations of externalizing problems (“well adjusted,” “hyperactive/oppositional,” and “aggressive/rule-breaking”) and transitions between groups from ages 4, 8, and 12. A “defiant/deceitful” group also emerged at age 12. Girls were generally more likely to present as well adjusted than boys. Children with recent physical abuse allegations had an increased risk for aggressive/rule-breaking presentations during the preschool and preadolescent years, while children with sexual abuse or neglect allegations had lower probabilities of having well-adjusted presentations during middle childhood. These findings indicate that persistently severe aggressive conduct problems, which are related to the most concerning outcomes, can be identified early, particularly among neglected and physically and sexually abused children.
Mandatory influenza vaccination is associated with improved healthcare personnel vaccination rates, but institutional barriers to implementation and enforcement are reported. We explored barriers and facilitators to mandatory vaccination among a national sample of hospital administrators. Support from employees and administration were cited as key to the success of a mandate.
The present study examined the specificity of autobiographical memory in adolescents and adults with versus without child sexual abuse (CSA) histories. Eighty-five participants, approximately half of whom per age group had experienced CSA, were tested on the Autobiographical Memory Interview. Individual difference measures, including those for trauma-related psychopathology, were also administered. Findings revealed developmental differences in the relation between autobiographical memory specificity and CSA. Even with depression statistically controlled, reduced memory specificity in CSA victims relative to controls was observed among adolescents but not among adults. A higher number of posttraumatic stress disorder criteria met predicted more specific childhood memories in participants who reported CSA as their most traumatic life event. These findings contribute to the scientific understanding of childhood trauma and autobiographical memory functioning and underscore the importance of considering the role of age and degree of traumatization within the study of autobiographical memory.
Exposure to intrauterine growth restriction (IUGR) is an important risk factor for impaired learning and memory, particularly in males. Although the basis of IUGR-associated learning and memory dysfunction is unknown, potential molecular participants may be insulin-like growth factor 1 (Igf1) and its receptor, IGF1r. We hypothesized that transcript levels and protein abundance of Igf1 and IGF1r in the hippocampus, a brain region critical for learning and memory, would be lower in IUGR male rats than in age-matched male controls at birth (postnatal day 0, P0), at weaning (P21) and adulthood (P120). We also hypothesized that changes in messenger Ribonucleic acid (mRNA) transcript levels and protein abundance would be associated with specific histone marks in IUGR male rats. Lastly, we hypothesized that IUGR male rats would perform poorer on tests of hippocampal function at P120. IUGR was induced by bilateral ligation of the uterine arteries in pregnant dams at embryonic day 19 (term is 21 days). Hippocampal Igf1 mRNA transcript levels and protein abundance were unchanged in IUGR male rats at P0, P21 or P120. At P0 and P120, IGF1r expression was increased in IUGR male rats. At P21, IGF1r expression was decreased in IUGR male rats. Increased IGF1r expression was associated with more histone 3 lysine 4 dimethylation (H3K4Me2) in the promoter region. In addition, IUGR male rats performed poorer on intermediate-term spatial working memory testing at P120. We speculate that altered IGF1r expression in the hippocampus of IUGR male rats may play a role in learning and memory dysfunction later in life.
The aim of the present study was to assess the recent trends in the epidemiology of non-typhoid Salmonella in Israel using a sentinel laboratory-based surveillance network. Between 1999 and 2009, 8758 Salmonella stool isolates were reported by five sentinel laboratories. There was a significant decrease in the incidence rate of Salmonella isolates from 70·5/100 000 in 1999 to 21·6/100 000 in 2005 followed by a slight increase to 30·3/100 000 in 2009. Of all Salmonella, 64·3% were isolated from children in the 0–4 years age group. Up to 2008, S. Enteritidis was the most prevalent serotype and in 2009 S. Infantis emerged as the most common Salmonella serotype. The decrease in the incidence of S. Enteritidis and S. Typhimurium and increase in S. Infantis among humans were associated with a similar trend among breeding flocks, which followed significant preventive interventions conducted against S. Enteritidis and S. Typhimurium infections in poultry. Tight surveillance and education of food handlers and consumers should be enhanced to reduce the foodborne transmission of Salmonella in Israel.
The purpose of the present research was to examine Deese–Roediger–McDermott false memory for trauma-related and nontrauma-related lists in adolescents and adults with and without documented histories of child sexual abuse (CSA). Individual differences in psychopathology and adult attachment were also explored. Participants were administered free recall and recognition tests after hearing CSA, negative, neutral, and positive Deese–Roediger–McDermott lists. In free recall, CSA and negative lists produced the most false memory. In sharp contrast, for recognition, CSA lists enjoyed the highest d′ scores. CSA-group adolescents who evinced greater posttraumatic stress disorder (PTSD) symptoms had higher rates of false memory compared to (a) non-CSA group adolescents with higher PTSD symptom scores (free recall), and (b) CSA-group adolescents with lower PTSD symptom scores (recognition). Regression analyses revealed that individuals with higher PTSD scores and greater fearful-avoidant attachment tendencies showed less proficient memory monitoring for CSA lists. Implications for trauma and memory development and for translational research are discussed.
The performance of InGaAs/GaAs pseudomorphic high electron mobility transistors is anticipated to improve with increased channel thickness due to reduced effects of quantum confinement. However, greater channel thicknesses increase the probability of forming misfit dislocations which have been reported to impair device properties. We characterized the composition and thickness of the active layer in Al0.25Ga0.75As / In0.21Ga0.79As structures with different channel thicknesses (75 Å - 300 Å) to within ± 0.005 and ± 8 Å using high resolution x-ray techniques. We determined, using Hall and rf measurements, that the device properties of these structures improved with increasing thickness up to about 185-205 Å; degraded properties were observed for thicker channel layers. Cathodoluminescence results indicate that the mosaic spread observed in x-ray triple axis rocking curves of these device structures is due to the presence of misfit dislocations. Thus, even though misfit dislocations are present, the device structure performs best with a channel thickness of ∼185 Å. These results demonstrate that one can fabricate functional devices in excess of critical thickness considerations, and that these x-ray techniques provide an effective means to evaluate structural properties prior to device processing.
BaTiO3 epitaxial films have been prepared on (001) MgO substrates by metalorganic chemical vapor deposition. The as‐deposited 0.2 μm thick films had a surface roughness of 12 nm. Channel waveguides were fabricated from the films and the optical throughput measured. To differentiate the surface scattering loss from the internal scattering loss, waveguides were also prepared with a surface planarization step to reduce the surface roughness to 2.5 nm. The waveguide loss was greatly reduced for the planarized waveguides. The results indicate that surface and side wall roughness accounted for the majority of the waveguide loss. Grain boundary grooving lead to surface roughness and routes to overcome this problem are discussed.
Guided-wave absorption and fluorescence in epitaxial Er:BaTiO3 thin film channel waveguides on MgO are reported. Guided- wave absorption is strongly dependent on post- growth annealing. Stimulated emission over a 40 nm bandwidth (λcente - 1.54 μm) has been achieved in oxygen-annealed waveguides. At 1.54 μm the absorption is reduced from ∼ -2 dB/cm to -∼-1.3 dB/cm in a 2.2 mm long 5 μm wide channel waveguide due the presence of the pump light.
Background: To compare the frequencies of risk factors, we describe risks for depression as a function of race among consecutively admitted participants in a randomized clinical trial of indicated depression prevention in later life.
Methods: Seventy-two black and 143 white participants were screened for risk factors for depression.
Results: Black participants were more likely to have fewer years of education and lower household income. They were more likely to be obese, live alone, experience functional disability, have a history of alcohol and drug abuse, and have lower scores on the Mini-mental State Examination and the Executive Interview (EXIT). White participants were not found to have greater prevalence or higher mean score on any risk factor. On average, black participants experienced approximately one more risk factor than white participants (t(213) = 3.32, p = 0.0011).
Conclusions: In our sample, black participants had higher frequencies of eight risk factors for depression and a greater mean number of risk factors compared to white participants.
This volume is dedicated to the memory of John G. Harris, whose life ended prematurely on the 6th of May, 2006. John's friendship and research impacted many people – he was a dedicated and loving husband, an accomplished scientist and applied mathematician, a passionate teacher, and an important mentor to many young scientists. This book was originally intended to be John's second book on elastic wave theory and diffraction. It grew from four lectures that were given at the Department of Mathematics and Mechanics, within IIMAS, at the National Autonomous University of Mexico, in January 2004. After John's passing, several of his colleagues, inspired by his wife Beatriz, began to convert these unfinished notes into a form suitable for publication. We have worked to combine the existing chapters with additional, contributed chapters from experts in the field of elastic wave theory.
Born and raised in Toronto, John entered McGill University as a mature student and graduated with a Bachelors in Electrical Engineering (Honours). After receiving a Masters of Science in Applied Physics from Stanford University, John traveled to Northwestern University to work toward a doctorate in Applied Mathematics with Jan Achenbach, which he completed in 1979. J. D. Achenbach had a lasting impact on John's work in elastic wave scattering, which formed the basis of much of John's research as a professor at the Department of Theoretical and Applied Mechanics at the University of Illinois at Urbana–Champaign between 1979 and 2005.
Early results from the SAGE-SMC (Surveying the Agents of Galaxy Evolution in the tidally-disrupted, low-metallicity Small Magellanic Cloud) Spitzer legacy program are presented. These early results concentrate on the SAGE-SMC MIPS observations of the SMC Tail region. This region is the high H i column density portion of the Magellanic Bridge adjacent to the SMC Wing. We detect infrared dust emission and measure the gas-to-dust ratio in the SMC Tail and find it similar to that of the SMC Body. In addition, we find two embedded cluster regions that are resolved into multiple sources at all MIPS wavelengths.
Verbal learning and memory deficits are frequent among patients with schizophrenia and correlate with reduced magnetic resonance imaging (MRI) volumes of the hippocampus in these patients. A crucial question is the extent to which interrelated structural-functional deficits of the hippocampus reflect a vulnerability to schizophrenia, as opposed to the disorder per se.
We combined brain structural measures and the Rey Auditory Verbal Learning Test (RAVLT) to assess hippocampal structure and function in 36 never-medicated individuals suspected to be in early (EPS) or late prodromal states (LPS) of schizophrenia relative to 30 healthy controls.
Group comparisons revealed bilaterally reduced MRI hippocampal volumes in both EPS and LPS subjects. In LPS subjects but not in EPS subjects, these reductions were correlated with poorer performance in RAVLT delayed recall.
Our findings suggest progressive and interrelated structural-functional pathology of the hippocampus, as prodromal symptoms and behaviours accumulate, and the level of risk for psychosis increases. Given the inverse correlation of learning and memory deficits with social and vocational functioning in established schizophrenia, our findings substantiate the rationale for developing preventive treatment strategies that maintain cognitive capacities in the at-risk mental state.
We are performing a uniform and unbiased imaging survey of the Large Magellanic Cloud (LMC), using the IRAC and MIPS instruments on board the Spitzer Space Telescope (Spitzer). Meixner et al. (2006) provides an overview of the project and initial results and their Table 1 (repeated here) outlines the survey's salient characteristics. In this project, we are surveying the agents of a galaxys evolution (SAGE), i.e. the interstellar medium (ISM) and stars, and their interaction on the galaxy wide scale of the LMC. Spitzer IRAC and MIPS images provide key insights into the life cycle of matter in a galaxy because the infrared emission from dust grains is an effective tracer of the ISM, star formation, and stellar mass-loss. Three key science goals determined the coverage and depth of the survey. The detection of diffuse ISM with column densities > 1.2×1021 H cm−2 permits detailed studies of dust processes in the ISM. SAGE's point source sensitivity enables a complete census of newly formed stars with masses >3 M⊙ that will determine the current star formation rate in the LMC. SAGE's detection of evolved stars with mass loss rates > 10−8 M⊙ yr−1 will quantify the rate at which evolved stars inject mass into the ISM of the LMC (Blum et al. 2006). The SAGE data are nonproprietary. The preliminary SAGE catalog of epoch 1 photometry, prepared by the SAGE Team and released to the public on January 3, 2006, contains over 4 million IRAC sources, band merged with 2MASS photometry and over 60,000 MIPS 24 micron sources. Preliminary estimates indicate that foreground Milky Way stars and background galaxies may comprise as much as 18% and 12%, respectively, of these catalogs. To learn more about the SAGE project: http://sage.stsci.edu/.