Automated classification of depression from structural brain measures across two independent community‐based cohorts

Major depressive disorder (MDD) has been the subject of many neuroimaging case–control classification studies. Although some studies report accuracies ≥80%, most have investigated relatively small samples of clinically‐ascertained, currently symptomatic cases, and did not attempt replication in larger samples. We here first aimed to replicate previously reported classification accuracies in a small, well‐phenotyped community‐based group of current MDD cases with clinical interview‐based diagnoses (from STratifying Resilience and Depression Longitudinally cohort, ‘STRADL’). We performed a set of exploratory predictive classification analyses with measures related to brain morphometry and white matter integrity. We applied three classifier types—SVM, penalised logistic regression or decision tree—either with or without optimisation, and with or without feature selection. We then determined whether similar accuracies could be replicated in a larger independent population‐based sample with self‐reported current depression (UK Biobank cohort). Additional analyses extended to lifetime MDD diagnoses—remitted MDD in STRADL, and lifetime‐experienced MDD in UK Biobank. The highest cross‐validation accuracy (75%) was achieved in the initial current MDD sample with a decision tree classifier and cortical surface area features. The most frequently selected decision tree split variables included surface areas of bilateral caudal anterior cingulate, left lingual gyrus, left superior frontal, right precentral and paracentral regions. High accuracy was not achieved in the larger samples with self‐reported current depression (53.73%), with remitted MDD (57.48%), or with lifetime‐experienced MDD (52.68–60.29%). Our results indicate that high predictive classification accuracies may not immediately translate to larger samples with broader criteria for depression, and may not be robust across different classification approaches.     

Continent-wide risk assessment for the establishment of nonindigenous species in Antarctica

Invasive alien species are among the primary causes of biodiversity change globally, with the risks thereof broadly understood for most regions of the world. They are similarly thought to be among the most significant conservation threats to Antarctica, especially as climate change proceeds in the region. However, no comprehensive, continent-wide evaluation of the risks to Antarctica posed by such species has been undertaken. Here we do so by sampling, identifying, and mapping the vascular plant propagules carried by all categories of visitors to Antarctica during the International Polar Year''s first season (2007–2008) and assessing propagule establishment likelihood based on their identity and origins and on spatial variation in Antarctica''s climate. For an evaluation of the situation in 2100, we use modeled climates based on the Intergovernmental Panel on Climate Change''s Special Report on Emissions Scenarios Scenario A1B [Nakićenović N, Swart R, eds (2000) Special Report on Emissions Scenarios: A Special Report of Working Group III of the Intergovernmental Panel on Climate Change (Cambridge University Press, Cambridge, UK)]. Visitors carrying seeds average 9.5 seeds per person, although as vectors, scientists carry greater propagule loads than tourists. Annual tourist numbers (∼33,054) are higher than those of scientists (∼7,085), thus tempering these differences in propagule load. Alien species establishment is currently most likely for the Western Antarctic Peninsula. Recent founder populations of several alien species in this area corroborate these findings. With climate change, risks will grow in the Antarctic Peninsula, Ross Sea, and East Antarctic coastal regions. Our evidence-based assessment demonstrates which parts of Antarctica are at growing risk from alien species that may become invasive and provides the means to mitigate this threat now and into the future as the continent''s climate changes.     

Trends in live births by mother's country of birth and other factors affecting low birthweight in England and Wales, 1983-2001

This article investigates trends in low birthweight singleton live births by mother's country of birth. 11.4 million birth records from registration data in England and Wales from 1983 to 2001 were used. The analysis focuses on births to mothers born in the UK and countries that contribute to the main ethnic minority groups in England and Wales. The results show that the prevalence of low birthweight babies varies by mother's country of birth. Important differentials also exist by mother's age at birth, multiplicity and registration status.     

Echocardiography‐Guided or “Sided” Pericardiocentesis

Echocardiography‐guided pericardiocentesis is the first choice method for relieving cardiac tamponade, but the exact role of the echocardiography at the moment of the puncture is still controversial. In this report, detailed echocardiographic evaluation was performed in 21 consecutive patients with cardiac tamponade just before the pericardiocentesis. Appropriate needle position was determined according to the probe position using imaginary x, y, and z axes. Pericardiocentesis was performed successfully using this technique without simultaneous echocardiography and no complications were observed. We concluded that bedside echocardiography with detailed evaluation of the puncture site and angle is enough for pericardiocentesis instead of real time guiding.     

Psychological Characteristics of Problem Gamblers With and Without Mood Disorder

Objective:

Problem and pathological gamblers are significantly more likely to experience mood disorders, compared with the general population. Our study examined the relation of psychological characteristics (personality, trait impulsiveness, and gambling motives) to current co-occurring mood disorder (major depression and dysthymia) status among problem and pathological gamblers.

Method:

Problem and pathological gamblers (N = 150) underwent a clinical interview to assess current co-occurring mood disorders; participants completed measures of problem gambling severity, personality, impulsiveness, and gambling motives.

Results:

Problem and pathological gamblers with a current co-occurring mood disorder were more likely to be female, older, and to report higher lifetime and past-year gambling severity. A co-occurring mood disorder was associated with higher personality scores for alienation and stress reaction, lower scores for well-being, social closeness, and control, as well as higher impulsiveness scores for urgency and lack of premeditation, and lower sensation seeking scores. Participants with a co-occurring mood disorder also reported higher coping motives for gambling. Multivariate logistic regression analyses demonstrated that personality factors (lower social closeness and higher alienation) contributed to the greatest likelihood of being diagnosed with a co-occurring mood disorder.

Conclusions:

Mood disorders frequently co-occur with problem and pathological gambling, and they are associated with greater gambling severity. These findings highlight that interpersonal facets of personality contribute substantially to co-occurring mood disorder status. Implications for treatment will be discussed.     

Rational design of self-assembly pathways for complex multicomponent structures

The field of complex self-assembly is moving toward the design of multiparticle structures consisting of thousands of distinct building blocks. To exploit the potential benefits of structures with such “addressable complexity,” we need to understand the factors that optimize the yield and the kinetics of self-assembly. Here we use a simple theoretical method to explain the key features responsible for the unexpected success of DNA-brick experiments, which are currently the only demonstration of reliable self-assembly with such a large number of components. Simulations confirm that our theory accurately predicts the narrow temperature window in which error-free assembly can occur. Even more strikingly, our theory predicts that correct assembly of the complete structure may require a time-dependent experimental protocol. Furthermore, we predict that low coordination numbers result in nonclassical nucleation behavior, which we find to be essential for achieving optimal nucleation kinetics under mild growth conditions. We also show that, rather surprisingly, the use of heterogeneous bond energies improves the nucleation kinetics and in fact appears to be necessary for assembling certain intricate 3D structures. This observation makes it possible to sculpt nucleation pathways by tuning the distribution of interaction strengths. These insights not only suggest how to improve the design of structures based on DNA bricks, but also point the way toward the creation of a much wider class of chemical or colloidal structures with addressable complexity.Recent experiments with short pieces of single-stranded DNA (1, 2) have shown that it is possible to assemble well-defined molecular superstructures from a single solution with more than merely a handful of distinct building blocks. These experiments use complementary DNA sequences to encode an addressable structure (3) in which each distinct single-stranded “brick” belongs in a specific location within the target assembly. A remarkable feature of these experiments is that even without careful control of the subunit stoichiometry or optimization of the DNA sequences, a large number of 2- and 3D designed structures with thousands of subunits assemble reliably (1, 2, 4, 5). The success of this approach is astounding given the many ways in which the assembly of an addressable structure could potentially go wrong (6–8).Any attempt to optimize the assembly yield or to create even more complex structures should be based on a better understanding of the mechanism by which DNA bricks manage to self-assemble robustly. The existence of a sizable nucleation barrier, as originally proposed in refs. 1, 2, would remedy two possible sources of error that were previously thought to limit the successful assembly of multicomponent nanostructures: the depletion of free monomers and the uncontrolled aggregation of partially formed structures. Slowing the rate of nucleation would suppress competition among multiple nucleation sites for available monomers and give the complete structure a chance to assemble before encountering other partial structures. Recent simulations of a simplified model of a 3D addressable structure have provided evidence of a free-energy barrier for nucleation (9), suggesting that the ability to control this barrier should enable the assembly of a wide range of complex nanostructures. We therefore need to be able to predict how such a barrier depends on the design of the target structure and on the choice of DNA sequences. Until now, however, there have been no reliable techniques to predict the existence, let alone the magnitude, of a nucleation barrier for self-assembly in a mixture of complementary DNA bricks.Here we show that the assembly of 3D DNA-brick nanostructures is indeed a nucleated process, but only in a narrow range of temperatures. The nucleation barrier in these systems is determined entirely by the topology of the designed interactions that stabilize the target structure. Controllable nucleation is therefore a general feature of addressable structures that can be tuned through the rational choice of designed interactions. We find that the reliable self-assembly of 3D DNA bricks is a direct consequence of their unusual nucleation behavior, which is not accounted for by existing theories that work for classical examples of self-assembly, such as crystal nucleation. We are thus able to provide a rational basis for the rather unconventional protocol used in the recent DNA-brick experiments by showing that they exploit a narrow window of opportunity where robust multicomponent self-assembly can take place.     

Pulmonary artery to aorta ratio for the detection of pulmonary hypertension: cardiovascular magnetic resonance and invasive hemodynamics in heart failure with preserved ejection fraction

Background

Previous work indicates that dilatation of the pulmonary artery (PA) itself or in relation to the ascending aorta (PA:Ao ratio) predicts pulmonary hypertension (PH). Whether these results also apply for heart failure with preserved ejection fraction (HFpEF) is unknown.In the present study we evaluated the diagnostic and prognostic power of PA diameter and PA:Ao ratio on top of right ventricular (RV) size, function, and septomarginal trabeculation (SMT) thickness by cardiovascular magnetic resonance (CMR) in HFpEF.

Methods and Results

159 consecutive HFpEF patients were prospectively enrolled. Of these, 111 underwent CMR and invasive hemodynamic evaluation.By invasive assessment 64 % of patients suffered from moderate/severe PH (mean pulmonary artery pressure (mPAP) ≥30 mmHg). Significant differences between groups with and without moderate/severe PH were observed with respect to PA diameter (30.9 ± 5.1 mm versus 26 ± 5.1 mm, p < 0.001), PA:Ao ratio (0.93 ± 0.16 versus 0.78 ± 0.14, p < 0.001), and SMT diameter (4.6 ± 1.5 mm versus 3.8 ± 1.2 mm; p = 0.008). The strongest correlation with mPAP was found for PA:Ao ratio (r = 0.421, p < 0.001). By ROC analysis the best cut-off for the detection of moderate/severe PH was found for a PA:Ao ratio of 0.83.Patients were followed for 22.0 ± 14.9 months. By Kaplan Meier analysis event-free survival was significantly worse in patients with a PA:Ao ratio ≥0.83 (log rank, p = 0.004). By multivariable Cox-regression analysis PA:Ao ratio was independently associated with event-free survival (p = 0.003).

Conclusion

PA:Ao ratio is an easily measureable noninvasive indicator for the presence and severity of PH in HFpEF, and it is related with outcome.     

Transradial catheterization may decrease the radial artery luminal diameter and impair the vasodilatation response in the access site at late term: an observational study

The present study aimed to evaluate the late-term changes in radial artery luminal diameter (RAD) and vasodilatation response following transradial catheterization (TRC). TRC-inducing trauma to radial artery intima may trigger chronic phase vascular changes and lead to anatomical and functional impairment. There is controversial data whether the impairment persists or repairs later. Fifty-six consecutive patients undergoing TRC were enrolled prospectively. Baseline RAD, flow-mediated dilatation (FMD) and nitroglycerin-mediated dilatation (NMD) of the radial artery at the access site were measured before TRC by high-resolution ultrasound. Six months later; RAD, FMD and NMD were measured again at the same access site. RAD at the sixth month was reduced compared with pre-procedural measurements (2.85 ± 0.44 versus 2.74 ± 0.42 mm, p = 0.0001).The average FMD decreased to 5.66 ± 5.87 %, which was significantly lower than the observed pre-procedural FMD (9.45 ± 5.01 %) 6 months after TRC (p = 0.0001). Likewise, the average NMD at the sixth month was reduced compared with pre-procedural NMD (9.52 ± 6.77 versus 6.64 ± 6.51 %, p = 0.018). Logistic regression analysis indicated that pre-procedural radial artery diameter to sheath size ratio was the independent predictor of NMD reduction (95 % confidence interval, β = ?9.74, p = 0.024). TRC may lead to a significant luminal diameter reduction and impairment of vasodilatation response in the radial artery at late term.     

Risk factors for low birthweight based on birth registration and census information, England and Wales, 1981-2000

This study examines whether there are socio-demographic factors (collected at census) that are not routinely available at birth registration that help to explain low birthweight in England and Wales in the 1980s and 1990s. Maternal age and marital status at the time of birth are known to affect the risk of low birthweight. The article looks at whether the additional socio-demographic information about the mother that is collected at Census modifies our understanding. It identifies specific groups at high risk of this negative birth outcome--being a mother from a non-White ethnic group, having a long-standing illness and living in a deprived area.     

Physical health status in relation to self-forgiveness and other-forgiveness in healthy college students

We extended prior research on the medical health-correlates of forgiving others by examining the relationship between self-forgiveness, other-forgiveness and health. Results derived from a cross-sectional survey of 266 healthy undergraduates showed that these dimensions of forgiveness were positively related to perceived physical health. Regression analysis revealed that self-forgiveness uniquely predicted a significant amount of variance in perceived physical health, and predicted more variance than did other-forgiveness. These results are discussed in light of the limitations of the current study and directions for future research.