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 firstname.lastname@example.org
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.
OBJECTIVES/GOALS: To examine the relationship between epigenetic age acceleration (EAA) and depressive symptoms in a cohort of African American women (AAW) with cardiometabolic conditions (CMC) including hypertension, diabetes, obesity; and to explore clinical phenotypes of depressive symptoms in this population. METHODS/STUDY POPULATION: This secondary analysis utilized genomic and longitudinal clinical data from AAW in the InterGEN cohort (n = 250). EWAS data was used to estimate EAA based on the Horvath method, which incorporates the DNA methylation statuses at 353 specific CpG sites and regresses this epigenetic age on chronological age to determine EAA. Pearson’s correlations and linear regression will be used to examine the relationship between EAA and depressive symptoms and a linear mixed model will investigate this relationship over four time points during a two-year period. Clinical phenotyping of depressive symptoms will be explored using a cluster analysis. RESULTS/ANTICIPATED RESULTS: Analysis is underway and will be complete by the time of presentation. We hypothesize that higher EAA will associate with higher depressive symptoms and poorer trajectories over time. We expect that this relationship may be meditated by the presence of CMCs. Exploratory analysis of clinical phenotyping is expected to provide descriptive evidence with respect to specific depressive symptoms or clusters which are most associated with EAA and CMCs. These results will address several gaps. To our knowledge, this is the first study to examine the relationship of EAA and depressive symptoms considering the role of CMC, in a historically understudied population with disproportionate risk. DISCUSSION/SIGNIFICANCE OF IMPACT: Depression limits life quality and quantity and is highly comorbid in CMC. AAW have high risk of comorbidity, and this study furthers knowledge of depression and aging with a clinically accessible marker and aids recognition of a heterogenous phenotype in an undertreated population.
In this paper, the generation of relativistic electron mirrors (REM) and the reflection of an ultra-short laser off the mirrors are discussed, applying two-dimension particle-in-cell simulations. REMs with ultra-high acceleration and expanding velocity can be produced from a solid nanofoil illuminated normally by an ultra-intense femtosecond laser pulse with a sharp rising edge. Chirped attosecond pulse can be produced through the reflection of a counter-propagating probe laser off the accelerating REM. In the electron moving frame, the plasma frequency of the REM keeps decreasing due to its rapid expansion. The laser frequency, on the contrary, keeps increasing due to the acceleration of REM and the relativistic Doppler shift from the lab frame to the electron moving frame. Within an ultra-short time interval, the two frequencies will be equal in the electron moving frame, which leads to the resonance between laser and REM. The reflected radiation near this interval and corresponding spectra will be amplified due to the resonance. Through adjusting the arriving time of the probe laser, a certain part of the reflected field could be selectively amplified or depressed, leading to the selective adjustment of the corresponding spectra.
In nonlinear dynamics, there are three classic routes to chaos, namely the period-doubling route, the Ruelle–Takens–Newhouse route and the intermittency route. The first two routes have previously been observed in self-excited thermoacoustic systems, but the third has not. In this experimental study, we present evidence of the intermittency route to chaos in the self-excited regime of a prototypical thermoacoustic system – a laminar flame-driven Rijke tube. We identify the intermittency to be of type II from the Pomeau–Manneville scenario through an analysis of (i) the probability distribution of the quiescent epochs between successive bursts of chaos, (ii) the first return map, and (iii) the recurrence plot. By establishing the last of the three classic routes to chaos, this study strengthens the universality of how strange attractors arise in self-excited thermoacoustic systems, paving the way for the application of generic suppression strategies based on chaos control.
Increasing evidence indicates that major depressive disorder (MDD) is associated with cognitive as well as mood disturbances.
To evaluate cognitive function and white matter structure, resting-state brain function in first-episode, treatmentnaive patients with MDD.
To explore brain structure and function mechanisms of cognitive impairment in MDD.
46 Han Chinese MDD patients aged 18–45 year and 46 controls were assessed by a series of validated test procedures.Then, 30 patients and 30 controls were obtained by MRI scan.White matter abnormalities evaluated using diffusion tensor imaging (DTI) were analyzed using tract based spatial statistics (TBSS) and resting-state brain function was evaluated using regional homogeneity (ReHo) analysis.
Cognitive impairment in patients with MDD was demonstrated by reduced accuracy in the Wisconsin Card Sorting test (WSCT) and to a lesser extent the Continuous Performance test (CPT) and Trail Making tests (TMT). White matter abnormalities found in the left cerebellum, and resting-state abnormalities present in the left inferior parietal gyrus, left anterior cingulate nucleus and left hippocampal gyrus were associated with impaired performance in the WSCT and CPT tests. We also showed that poor WSCT performance was associated with increased interconnectivity between the left ventral anterior cingulate nucleus and the medial frontal lobe areas.
The present study indicates cognitive disturbances in patients with MDD are associated with white matter and resting-state changes and altered interconnections in specific brain areas.
Postoperative nausea and vomiting (PONV) is the most common postoperative complication after gynecological laparoscopic surgery. It is unknown whether the occurrence of PONV is associated with the preoperative psychological status.
To explore the effects of preoperative psychological status on the incidence of PONV following gynecological laparoscopic surgery.
To analyze the possible risk factors in order to prevent and treat PONV after gynecological laparoscopic surgery.
101 cases patients who underwent gynecological laparoscopic surgery were enrolled. Self-rating anxiety scale (SAS) and self-rating depression scale (SDS) were used to assess the preoperative psychological state. Visual analog scale nausea (NVAS) was used to evaluate the occurrence of PONY within the postoperative 24 hours.
101 patients completed NVAS and 72 patients completed SAS and SDS. The incidence of PONV was 45.5%. The standard score of SAS (49.14±8.01) in PONV group was significantly higher than that in Non-PONV group (44.54±7.58) t=2.505, P < 0.05. The ratio of preoperative anxiety patients(SAS≥50) in PONV group(57%) was higher than that in Non-PONV group (30%) (χ2=5.513, P < 0.05). It showed that the occurrence of PONV was positively correlated with preoperative anxiety (r=0.277, P < 0.05). There was no difference in the scores of SDS between two groups. No correlation was found between PONV and preoperative depression.
Higher level of anxiety before surgery may increase the risk of PONV. The patients undergoing gynecological laparoscopic surgery should reduce the level of anxiety with appropriate psychological counseling or prophylactic anti-anxiety drugs.
This article explores the discursive functioning of education policies, bringing into consideration community perspectives regarding policy enactment in contemporary China. With the intention of building upon ongoing discussions surrounding both the conceptions and purposes of policy sociology, we critically analyse policies directly related to the education of migrant children living in and around China's largest urban centres, with a specific focus on those implemented in Beijing. We emphasize two important aspects that previous studies of China's education policies have tended to underplay given their focus on social-economic perspectives. The first argument is that education policies have an underlying agenda that extends beyond that of simply addressing the educational needs of migrant children – evidenced through the discursive functions of policy texts. The second argument is related and seeks to raise questions about who is best served by these policies and for whom these policies are intended.
Bennett Island stands alone in a remote part of the Arctic and information on its geology is essential to ascertain relations with other terranes in order to restore the early Palaeozoic Arctic palaeogeography. Lower Palaeozoic sedimentary rocks throughout the island were studied thoroughly for the first time. The Ordovician section (> 1.1 km thick) comprises three units: Tremadocian, lowest Floian black shale (130–140 m); Floian, lower Dapingian carbonate turbidite (> 250 m); and Dapingian, lower Darriwilian siliciclastic turbidite (> 730 m). Ordovician deposits conformably overlie Cambrian rocks deposited within the Siberian shelf, as shown earlier. Most of the Ordovician succession was formed in a deep trough that received carbonate debris from a nearby carbonate platform and silicate material from a distant landmass located to the NE (present coordinates). The Bennett Island Ordovician rocks have much in common with those of both the Central and Northern Taimyr belts. It could be tentatively suggested that both belts merged at their eastern continuation in the vicinity of De Long Islands. The whole system probably extends further eastwards. The Ordovician facies patterns and faunal assemblages in the New Siberian Islands are notably similar to those of northwestern Alaska, where the same lateral transition from turbidites to shelf limestones was reported.
Patients with severe mental disorders in low-resource settings have limited access to services, resulting in overwhelming caregiving burden for families. In extreme cases, this has led to the long-term restraining of patients in their homes. China underwent a nationwide initiative to unlock patients and provide continued treatment. This study aims to quantify household economic burden in families after unlocking and treatment, and to identify factors associated with increased burden due to schizophrenia.
A total of 264 subjects were enrolled from three geographically diverse provinces in 2012. Subjects were patients with schizophrenia who were previously put under restraints and had participated in the ‘unlocking and treatment’ intervention. The primary outcome was the current household economic burden, obtained from past year financial information collected through on-site interview. Patient disease characteristics, treatment, outcomes and family caregiving burden were collected as well. Univariate and multivariate linear regression were used to construct risk factor models for indirect economic burden.
After participating in the intervention, 85% of patients continued to receive mental health services, 70% used medication as prescribed and 80% were never relocked. Family members reported significantly decreased caregiving burden after receiving the intervention. Mean direct and indirect household economic burdens were CNY963 (US$31.7) and CNY11 724 (US$1670) per year, respectively, while family total income was on average CNY12 108 (US$1913) per year. Greater disease severity and poorer patient psychosocial function at time of study were found to be independent factors related to increased indirect burden.
The ‘unlocking and treatment’ intervention has improved the lives of patients and families. Indirect burden due to disease is still a major economic issue that needs to be addressed, potentially through improving treatment and patient functioning. Our findings contribute to the unravelling and eventual elimination of chronic restraining of mentally ill patients in low-resource settings.
In self-excited combustion systems, the application of open-loop forcing is known to be an effective strategy for controlling periodic thermoacoustic oscillations, but it is not known whether and under what conditions such a strategy would work on thermoacoustic oscillations that are not simply periodic. In this study, we experimentally examine the effect of periodic acoustic forcing on a prototypical thermoacoustic system consisting of a ducted laminar premixed flame oscillating quasiperiodically on an ergodic
torus at two incommensurate natural frequencies,
. Compared with that of a classical period-1 system, complete synchronization of this
system is found to occur via a more intricate route involving three sequential steps: as the forcing amplitude,
, increases at a fixed forcing frequency,
, the system transitions first (i) to ergodic
quasiperiodicity; then (ii) to resonant
quasiperiodicity as the weaker of the two natural modes,
, synchronizes first, leading to partial synchronization; and finally (iii) to a
limit cycle as the remaining natural mode,
, also synchronizes, leading to complete synchronization. The minimum
required for partial and complete synchronization decreases as
, resulting in two primary Arnold tongues. However, when forced at an amplitude above that required for complete synchronization, the system can transition out of
. The optimal control strategy is to apply off-resonance forcing at a frequency around the weaker natural mode (
) and at an amplitude just sufficient to cause
, because this produces the largest reduction in thermoacoustic amplitude via asynchronous quenching. Analysis of the Rayleigh index shows that this reduction is physically caused by a disruption of the positive coupling between the unsteady heat release rate of the flame and the
acoustic modes. If the forcing is applied near the stronger natural mode (
), however, resonant amplification can occur. We then phenomenologically model this
thermoacoustic system as two reactively coupled van der Pol oscillators subjected to external sinusoidal forcing, and find that many of its synchronization features – such as the three-step route to
, the double Arnold tongues, asynchronous quenching and resonant amplification – can be qualitatively reproduced. This shows that these features are not limited to our particular system, but are universal features of forced self-excited oscillators. This study extends the applicability of open-loop control from classical period-1 systems with just a single time scale to ergodic
quasiperiodic systems with two incommensurate time scales.
Current adolescent substance use risk models have inadequately predicted use for African Americans, offering limited knowledge about differential predictability as a function of developmental period. Among a sample of 500 African American youth (ages 11–21), four risk indices (i.e., social risk, attitudinal risk, intrapersonal risk, and racial discrimination risk) were examined in the prediction of alcohol, marijuana, and cigarette initiation during early (ages 11–13), mid (ages 16–18), and late (ages 19–21) adolescence. Results showed that when developmental periods were combined, racial discrimination was the only index that predicted initiation for all three substances. However, when risk models were stratified based on developmental period, variation was found within and across substance types. Results highlight the importance of racial discrimination in understanding substance use initiation among African American youth and the need for tailored interventions based on developmental stage.
The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body mass index (BMI, kg/m2) and size at birth, and additionally to address other research questions such as long-term consequences of birth size. The project started in 2013 and is open to all twin projects in the world having height and weight measures on twins with information on zygosity. Thus far, 54 twin projects from 24 countries have provided individual-level data. The CODATwins database includes 489,981 twin individuals (228,635 complete twin pairs). Since many twin cohorts have collected longitudinal data, there is a total of 1,049,785 height and weight observations. For many cohorts, we also have information on birth weight and length, own smoking behavior and own or parental education. We found that the heritability estimates of height and BMI systematically changed from infancy to old age. Remarkably, only minor differences in the heritability estimates were found across cultural–geographic regions, measurement time and birth cohort for height and BMI. In addition to genetic epidemiological studies, we looked at associations of height and BMI with education, birth weight and smoking status. Within-family analyses examined differences within same-sex and opposite-sex dizygotic twins in birth size and later development. The CODATwins project demonstrates the feasibility and value of international collaboration to address gene-by-exposure interactions that require large sample sizes and address the effects of different exposures across time, geographical regions and socioeconomic status.
Elevated left ventricular end diastolic pressure is a risk factor for ventricular arrhythmias in patients with tetralogy of Fallot. The objective of this retrospective study was to identify echocardiographic measures associated with left ventricular end diastolic pressure >12 mmHg in this population. Repaired tetralogy of Fallot patients age ≥13 years, who underwent a left heart catheterisation within 7 days of having an echocardiogram were evaluated. Univariate comparison was made in echocardiographic and clinical variables between patients with left ventricular end diastolic pressure >12 versus ≤12 mmHg. Ninety-four patients (54% male) with a median age of 24.6 years were included. Thirty-four (36%) had left ventricular end diastolic pressure >12 mmHg. Patients with left ventricular end diastolic pressure >12mmHg were older (median 32.9 versus 24.0 years, p = 0.02), more likely to have a history of an aortopulmonary shunt (62% versus 38%, p = 0.03), and have a diagnosis of hypertension (24% versus 7%, p = 0.03) compared to those with left ventricular end diastolic pressure ≤12 mmHg. There were no significant differences in mitral valve E/A ratio, annular e’ velocity, or E/e’ ratio between patients with left ventricular end diastolic pressure >12 versus ≤12 mmHg. Patients with left ventricular end diastolic pressure >12mmHg had larger left atrial area (mean 17.7 versus 14.0 cm2, p = 0.03) and larger left atrium anterior–posterior diameter (mean 36.0 versus 30.6 mm, p = 0.004). In conclusion, typical echocardiographic measures of left ventricular diastolic dysfunction may not be reliable in tetralogy of Fallot patients. Prospective studies with the use of novel echocardiographic measures are needed.
To assess the safety of, and subsequent allergy documentation associated with, an antimicrobial stewardship intervention consisting of test-dose challenge procedures prompted by an electronic guideline for hospitalized patients with reported β-lactam allergies.
Retrospective cohort study.
Large healthcare system consisting of 2 academic and 3 community acute-care hospitals between April 2016 and December 2017.
We evaluated β-lactam antibiotic test-dose outcomes, including adverse drug reactions (ADRs), hypersensitivity reactions (HSRs), and electronic health record (EHR) allergy record updates. HSR predictors were examined using a multivariable logistic regression model. Modification of the EHR allergy record after test doses considered relevant allergy entries added, deleted, and/or specified.
We identified 1,046 test-doses: 809 (77%) to cephalosporins, 148 (14%) to penicillins, and 89 (9%) to carbapenems. Overall, 78 patients (7.5%; 95% confidence interval [CI], 5.9%–9.2%) had signs or symptoms of an ADR, and 40 (3.8%; 95% CI, 2.8%–5.2%) had confirmed HSRs. Most HSRs occurred at the second (ie, full-dose) step (68%) and required no treatment beyond drug discontinuation (58%); 3 HSR patients were treated with intramuscular epinephrine. Reported cephalosporin allergy history was associated with an increased odds of HSR (odds ratio [OR], 2.96; 95% CI, 1.34–6.58). Allergies were updated for 474 patients (45%), with records specified (82%), deleted (16%), and added (8%).
This antimicrobial stewardship intervention using β-lactam test-dose procedures was safe. Overall, 3.8% of patients with β-lactam allergy histories had an HSR; cephalosporin allergy histories conferred a 3-fold increased risk. Encouraging EHR documentation might improve this safe, effective, and practical acute-care antibiotic stewardship tool.
The Pain Catastrophizing Scale (PCS) measures three aspects of catastrophic cognitions about pain—rumination, magnification, and helplessness. To facilitate assessment and clinical application, we aimed to (a) develop a short version on the basis of its factorial structure and the items’ correlations with key pain-related outcomes, and (b) identify the threshold on the short form indicative of risk for depression.
Social centers for older people.
664 Chinese older adults with chronic pain.
Besides the PCS, pain intensity, pain disability, and depressive symptoms were assessed.
For the full scale, confirmatory factor analysis showed that the hypothesized 3-factor model fit the data moderately well. On the basis of the factor loadings, two items were selected from each of the three dimensions. An additional item significantly associated with pain disability and depressive symptoms, over and above these six items, was identified through regression analyses. A short-PCS composed of seven items was formed, which correlated at r=0.97 with the full scale. Subsequently, receiver operating characteristic (ROC) curves were plotted against clinically significant depressive symptoms, defined as a score of ≥12 on a 10-item version of the Center for Epidemiologic Studies-Depression Scale. This analysis showed a score of ≥7 to be the optimal cutoff for the short-PCS, with sensitivity = 81.6% and specificity = 78.3% when predicting clinically significant depressive symptoms.
The short-PCS may be used in lieu of the full scale and as a brief screen to identify individuals with serious catastrophizing.
A new generation of high power laser facilities will provide laser pulses with extremely high powers of 10 petawatt (PW) and even 100 PW, capable of reaching intensities of
in the laser focus. These ultra-high intensities are nevertheless lower than the Schwinger intensity
at which the theory of quantum electrodynamics (QED) predicts that a large part of the energy of the laser photons will be transformed to hard Gamma-ray photons and even to matter, via electron–positron pair production. To enable the investigation of this physics at the intensities achievable with the next generation of high power laser facilities, an approach involving the interaction of two colliding PW laser pulses is being adopted. Theoretical simulations predict strong QED effects with colliding laser pulses of
focused to intensities
The feasibility of non-destructive detection and classification of in-shell insect-infested almonds was examined by using multispectral imaging (MSI) technology combined with chemometrics. Differentiation of reflectance spectral data between intact and insect-infested almonds was attempted by using analytical approaches based on principal component analysis and support vector machines, classification accuracy rates as high as 99.1% in the calibration set and 97.5% in the prediction set were achieved. Meanwhile, the in-shell almonds were categorized into three classes (intact, slightly infested and severely infested) based on the degree of damage caused by insect infestation and were characterized quantitatively by the analysis of shell/kernel weight ratio. A three-class model for the identification of intact, slightly infested and severely infested almonds yielded acceptable classification performance (95.6% accuracy in the calibration set and 93.3% in the prediction set). These results revealed that MSI technology combined with chemometrics may be a promising approach for the non-destructive detection of hidden insect damage in almonds and could be used for industrial applications.
Ultra-diffuse galaxies (UDGs) have sizes comparable to the Milky Way and stellar masses of about 1/1000 of it. They attracted a lot of attention as possible “dark galaxies” heavily dominated by dark matter, however, no reliable dynamical mass estimates were done because of their extremely low surface brightness. We have recently found 13 gas free diffuse young (300–500 Myr) post-starburst galaxies (PSGs) without ongoing star formation in Coma and Abell 2147, which, should they continue to evolve passively, will become UDGs in 5 Gyr. We obtained deep spectroscopic observations for 11 diffuse PSGs and derived their internal kinematics and stellar population properties. All of them possess disk-like kinematics (substantial rotation, low stellar velocity dispersion) and likely experienced starburst episodes prior to the star formation quenching by ram pressure stripping. Our results suggest that at least some UDGs were “normal” intermediate to large-sized disk galaxies in the past, which were later quenched by dense environment.