The Dynamical Cluster Approximation: Non-Local Dynamics of Correlated Electron Systems

We recently introduced the dynamical cluster approximation(DCA), a new technique that includes short-ranged dynamical correlations in addition to the local dynamics of the dynamical mean field approximation while preserving causality. The technique is based on an iterative self-consistency scheme on a finite size periodic cluster. The dynamical mean field approximation (exact result) is obtained by taking the cluster to a single site (the thermodynamic limit). Here, we provide details of our method, explicitly show that it is causal, systematic, $\Phi$-derivable, and that it becomes conserving as the cluster size increases. We demonstrate the DCA by applying it to a Quantum Monte Carlo and Exact Enumeration study of the two-dimensional Falicov-Kimball model. The resulting spectral functions preserve causality, and the spectra and the CDW transition temperature converge quickly and systematically to the thermodynamic limit as the cluster size increases.Comment: 19 pages, 13 postscript figures, revte

Visual impairment due to retinopathy of prematurity and concomitant disabilities in the Netherlands

Aim: Determine incidence of visual impairment due to retinopathy of prematurity (ROP) and concomitant dis-abilities between 2009 and 2018 in the Netherlands and compare data to four former similar studies. Secondly, monitor if infants were missed for ROP-screening since the adoption of stricter, risk factor guided criteria (2013).Methods: Retrospective inventory on anonymous data of infants diagnosed with ROP from Dutch visual impairment-institutes. Data including: best corrected visual acuity, ROP-treatment and concomitant disabilities: bronchopulmonary dysplasia, behavioral abnormalities, epilepsy, hearing deficit, developmental delay, cerebral palsy and cerebral visual impairment. During the study period, lower age limit for neonatal life support (2010) and higher oxygen saturation targets (2014) were implemented.Results: Records of 53 infants were analyzed. Visual impairment incidence due to ROP was 2.02 per 100.000 live births (2000-2009: 1.84, p = 0.643). Compared to earlier periods (1975-2000), a significant decrease was observed. The incidence of concomitant disabilities remained stable. Mean gestational age (GA) continued to decrease to 26.6 & PLUSMN; 1.9 weeks (2000-2009: 27.4 & PLUSMN; 2.0 weeks, p = 0.047). All patients met the screening inclusion criteria.Conclusion: The incidence of visual impairment due to ROP and concomitant disabilities between 2009 and 2018 has not increased, despite lower GA and higher oxygen saturation targets. None of the infants were missed for ROP screening following introduction of more restricted screening inclusion criteria.Ophthalmic researc

Corpus callosum injury after neurosurgical intervention for posthemorrhagic ventricular dilatation and association with neurodevelopmental outcome at 2 years

OBJECTIVE Direct injury to the corpus callosum (CC) due to neurosurgical interventions in infants with posthemorrhagic ventricular dilatation (PHVD) has not been reported in the literature. The authors observed a subset of infants who had suffered penetrating CC injury after neurosurgical interventions for PHVD and hypothesized that this pattern of injury may result in suboptimal CC maturation and neurodevelopmental impairment.METHODS In this multicenter, retrospective, observational study, 100 preterm and 17 full-term infants with PHVD were included and compared with 23 preterm controls. Both neonatal and postneonatal brain MRI scans were assessed for injury, and measurements were performed on postneonatal MRI scans at 2 years' corrected age. Neurodevelopmental outcome was assessed at 2 years' corrected age.RESULTS A total of 269 brain MRI scans of 140 infants were included. Of infants with PHVD, 48 (41%) had penetrating CC injury following neurosurgical interventions. The median (IQR) CC midsagittal surface area was smaller in infants with CC injury when compared with infants with PHVD who had intact CC and controls (190 mm(2) [149-262 mm(2)] vs 268 mm(2) [206-318 mm(2)] vs 289 mm(2) [246-320 mm(2)], respectively; p < 0.001). In the univariate analysis, the area of the CC was associated with cognitive Z score (coefficient 0.009 [95% CI 0.005-0.012], p < 0.001) and motor Z score (coefficient 0.009 [95% CI 0.006-0.012], p < 0.001). In the multivariable model, CC injury was not independently associated with cognitive and motor Z score after adjusting for gestational age and presence of periventricular hemorrhagic infarction (coefficient 0.04 [95% CI -0.36 to 0.46] and -0.37 [95% CI -0.83 to 0.09], p = 0.7 and 0.1, respectively).CONCLUSIONS CC injury was not uncommon following neurosurgical interventions for PHVD in both preterm and full-term infants. At the age of 2 years, the CC midsagittal surface area was smaller in infants with injury, but CC injury was not independently associated with cognitive and motor outcomes at 2 years' corrected age.Developmen

Neurobiological correlates of antisociality across adolescence and young adulthood: a multi-sample, multi-method study

Pathways through Adolescenc

Transition pathways to sustainable agricultural water management: A review of integrated modeling approaches

Agricultural water management (AWM) is an interdisciplinary concern, cutting across traditional domains such as agronomy, climatology, geology, economics, and sociology. Each of these disciplines has developed numerous process-based and empirical models for AWM. However, models that simulate all major hydrologic, water quality, and crop growth processes in agricultural systems are still lacking. As computers become more powerful, more researchers are choosing to integrate existing models to account for these major processes rather than building new cross-disciplinary models. Model integration carries the hope that, as in a real system, the sum of the model will be greater than the parts. However, models based upon simplified and unrealistic assumptions of physical or empirical processes can generate misleading results which are not useful for informing policy. In this article, we use literature and case studies from the High Plains Aquifer and Southeastern United States regions to elucidate the challenges and opportunities associated with integrated modeling for AWM and recommend conditions in which to use integrated models. Additionally, we examine the potential contributions of integrated modeling to AWM - the actual practice of conserving water while maximizing productivity. Editor's note: This paper is part of the featured series on Optimizing Ogallala Aquifer Water Use to Sustain Food Systems. See the February 2019 issue for the introduction and background to the series.Peer reviewedPlant and Soil Science

Absence of Host Plasminogen Activator Inhibitor 1 Prevents Cancer Invasion and Vascularization

Acquisition of invasive/metastatic potential through protease expression is an essential event in tumor progression. High levels of components of the plasminogen activation system, including urokinase, but paradoxically also its inhibitor, plasminogen activator inhibitor 1 (PAI1), have been correlated with a poor prognosis for some cancers. We report here that deficient PAI1 expression in host mice prevented local invasion and tumor vascularization of transplanted malignant keratinocytes. When this PAI1 deficiency was circumvented by intravenous injection of a replication-defective adenoviral vector expressing human PAI1, invasion and associated angiogenesis were restored. This experimental evidence demonstrates that host-produced PAI is essential for cancer cell invasion and angiogenesis

Predictions of total and total reaction cross sections for nucleon-nucleus scattering up to 300 MeV

Total reaction cross sections are predicted for nucleons scattering from various nuclei. Projectile energies to 300 MeV are considered. So also are mass variations of those cross sections at selected energies. All predictions have been obtained from coordinate space optical potentials formed by full folding effective two-nucleon (NN) interactions with one body density matrix elements (OBDME) of the nuclear ground states. Good comparisons with data result when effective NN interactions defined by medium modification of free NN t matrices are used. Coupled with analyses of differential cross sections, these results are sensitive to details of the model ground states used to describe nuclei