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This paper evaluates whether educational outcomes of first-generation migrant children improved relative to those of natives after a policy change which delayed an important primary school exit test by three months. Using Dutch register data and a difference-in-differences methodology, we show that the policy change increased the academic rank of migrants relative to natives upon first enrollment. The policy change, therefore, has had an important positive effect on the educational chances of migrant children. Our analyses suggest that the results are driven by higher relative exit test scores and higher relative teacher recommendations. [ABSTRACT FROM AUTHOR]

The fouling kinetics and amount of calcium sulfate and calcium carbonate, respectively, on different polypropylene/graphite composites in a flat plate heat exchanger are determined and compared to the reference material stainless-steel. For a straight evaluation of the fouling susceptibility of the materials the formation of bubbles on the materials is considered by optical imaging or excluded by a degasser. The results are interpreted using surface free energy and roughness of the surfaces. The results show that when bubble formation is avoided, the polymer composites have a very low fouling tendency compared to stainless steel. This is particularly the case when turbulent flows are present or when sandblasted specimen are used. Sandblasting also continues to increase heat transfer compared to untreated samples by increasing thermal conductivity and creating local turbulences. Depending on the test conditions, the fouling resistance formed on the stainless-steel surface is an order of magnitude greater than on the polymer composites. In addition, the fouling layers adhere only weakly to the composites, which indicates an easy cleaning in place after the formation of deposits. [ABSTRACT FROM AUTHOR]

Introduction: Out-of-hospital cardiac arrest (OHCA) caused by an ST-elevation myocardial infarction (STEMI) is often accompanied by a sudden loss of consciousness that may cause the patient to collapse with resulting head trauma, leading to a suspicion of possible intracranial haemorrhage. To rule out intracranial haemorrhage before emergency percutaneous coronary intervention (PCI), emergency computed tomography (CT) of the head might be useful but also causes a delay in percutaneous STEMI treatment. Methods: The medical records of all adult patients that presented with OHCA to the emergency department (ED) of the University Medical Centre Utrecht (UMCU), the Netherlands between 16 February 2020 and 16 February 2022 were reviewed. Results: A total of 263 patients presented to the ED with an OHCA; 50 presented with a STEMI requiring emergency PCI. Thirty-nine (78%) patients with a STEMI were immediately referred to the catheterisation laboratory and 11 (22%) STEMI patients underwent a CT scan prior to emergency angiography; in no case was PCI deferred on the basis of the CT findings. The dominant indication for CT of the head was collapse, reported by 10 patients and resulting in a visible traumatic head injury in 7 patients. In none of the patients was intracranial haemorrhage detected. However, there was a delay between presentation to the ED and arrival at the catheterisation laboratory in patients who underwent CT of the head (mean 63 ± 25 min) before emergency PCI compared to patients without a CT scan (mean 37 ± 21 min). Conclusion: CT of the head did not result in a diagnosis of intracranial haemorrhage or deferral of PCI but did delay PCI treatment for STEMI in patients presenting with OHCA. [ABSTRACT FROM AUTHOR]

Sovereign credit ratings summarize the creditworthiness of countries. These ratings have a large influence on the economy and the yields at which governments can issue new debt. This paper investigates the use of a multilayer perceptron (MLP), classification and regression trees (CART), support vector machines (SVM), Naïve Bayes (NB), and an ordered logit (OL) model for the prediction of sovereign credit ratings. We show that MLP is best suited for predicting sovereign credit ratings, with a random cross-validated accuracy of 68%, followed by CART (59%), SVM (41%), NB (38%), and OL (33%). Investigation of the determining factors shows that there is some heterogeneity in the important variables across the models. However, the two models with the highest out-of-sample predictive accuracy, MLP and CART, show a lot of similarities in the influential variables, with regulatory quality, and GDP per capita as common important variables. Consistent with economic theory, a higher regulatory quality and/or GDP per capita are associated with a higher credit rating. [ABSTRACT FROM AUTHOR]

In this paper we present the comparison of experiments and numerical simulations for bubble cutting by a wire. The air bubble is surrounded by water. In the experimental setup an air bubble is injected on the bottom of a water column. When the bubble rises and contacts the wire, it is separated into two daughter bubbles. The flow is modeled by the incompressible Navier–Stokes equations. A meshfree method is used to simulate the bubble cutting. We have observed that the experimental and numerical results are in very good agreement. Moreover, we have further presented simulation results for liquid with higher viscosity. In this case the numerical results are close to previously published results. [ABSTRACT FROM AUTHOR]

Accurate and low-cost sleep measurement tools are needed in both clinical and epidemiological research. To this end, wearable accelerometers are widely used as they are both low in price and provide reasonably accurate estimates of movement. Techniques to classify sleep from the high-resolution accelerometer data primarily rely on heuristic algorithms. In this paper, we explore the potential of detecting sleep using Random forests. Models were trained using data from three different studies where 134 adult participants (70 with sleep disorder and 64 good healthy sleepers) wore an accelerometer on their wrist during a one-night polysomnography recording in the clinic. The Random forests were able to distinguish sleep-wake states with an F1 score of 73.93% on a previously unseen test set of 24 participants. Detecting when the accelerometer is not worn was also successful using machine learning ( F1-score > 93.31 % ), and when combined with our sleep detection models on day-time data provide a sleep estimate that is correlated with self-reported habitual nap behaviour ( r =. 60 ). These Random forest models have been made open-source to aid further research. In line with literature, sleep stage classification turned out to be difficult using only accelerometer data. [ABSTRACT FROM AUTHOR]

Kinetics and quantity of crystallization fouling of calcium carbonate on polyether ether ketone (PEEK) surfaces are studied and compared with those on stainless steel. A laboratory scale set-up of a flat plate polymer film heat exchanger was used as a screening apparatus for the fouling experiments. The scaling affinity of the polymeric surfaces was found to be low compared to the stainless steel surface under equivalent conditions. Additionally, the polymer surface appears to be easier to clean due to a low adhesiveness. The low adhesiveness of crystals on polymers is attributed to their different surface properties (surface free energy and roughness) compared to stainless steel. The quantity of the deposit is also affected by the degree of supersaturation arising from higher local temperatures and overall concentrations. The deposits on the polymeric films were analyzed with respect to their appearance, distribution and thickness. Scanning electron microscopy (SEM) and optical coherence tomography (OCT) are used to determine the morphology of the deposited material and the fouling layer thickness, respectively. [ABSTRACT FROM AUTHOR]

Purpose: Endurance exercise competitions have shown a transient negative effect on global right ventricular (RV) performance. Most published studies are based on terrestrial sports. The aim of our study was to evaluate the cardiac effects after an open water swimming race.Methods: We evaluated 33 healthy swimmers (mean age 40.9 ± 7.2) participating in a 9.5 km open water swimming race. All subjects underwent a standard transthoracic echocardiography including an evaluation of dimensions and myocardial ventricular deformation. Echocardiography was performed 24 h before and within the first hour of arrival at the finish line. Cardiac troponin I (cTn I), NT-ProBNP and leukocytes were also evaluated.Results: No changes in left ventricle (LV) ejection fraction or LV global longitudinal strain were observed. A significant increase in RV end-diastolic area (RVEDA) was noted after the race (RVEDA at baseline 15.12 ± 1.86; RVEDA after race 16.06 ± 2.27, p < 0.05), but no changes were seen in RV fractional area change or RV global longitudinal strain. Cardiac biomarkers and leukocytes significantly increased. No association was detected between the increase in cTn I or NT-proBNP and the RV acute dilatation or LV performance. A significant association was observed between cTn I and leukocytes (r = 0.375, p < 0.05).Conclusions: An acute RV dilatation but without an impairment in RV deformation was observed after participating in an endurance swimming race. The correlation between the increase in cTn I and leukocytes, but not with ventricular performance, may support the hypothesis of an exercise-induced increase in myocardial sarcolemmal permeability due to an inflammatory response rather than myocardial injury. [ABSTRACT FROM AUTHOR]

Intergenerational mobility is often studied using survey data. In such settings, selective unit or item non-response may bias estimates. Linking Dutch survey data to administrative income data allows us to examine whether selective responses bias the estimated relationship between parental income and children's mathematics and language test scores in grades 6 and 9. We find that the estimates of these relationships are biased downward due to parental unit non-response, while they are biased upwards due to item non-response. In the analyses of both unit and item non-response, the point estimates for language and mathematics test scores point in the same direction but only one of the two relationships is significant. These findings suggest that estimates of intergenerational mobility based on survey data need to be interpreted with caution because they may be biased by selective non-response. The direction of such bias is difficult to predict a priori. Bias due to unit and item non-response may work in opposing directions and may differ across outcomes. [ABSTRACT FROM AUTHOR]

White dwarfs are stellar embers depleted of nuclear energy sources that cool over billions of years1. These stars, which are supported by electron degeneracy pressure, reach densities of 107 grams per cubic centimetre in their cores2. It has been predicted that a first-order phase transition occurs during white-dwarf cooling, leading to the crystallization of the non-degenerate carbon and oxygen ions in the core, which releases a considerable amount of latent heat and delays the cooling process by about one billion years3. However, no direct observational evidence of this effect has been reported so far. Here we report the presence of a pile-up in the cooling sequence of evolving white dwarfs within 100 parsecs of the Sun, determined using photometry and parallax data from the Gaia satellite4. Using modelling, we infer that this pile-up arises from the release of latent heat as the cores of the white dwarfs crystallize. In addition to the release of latent heat, we find strong evidence that cooling is further slowed by the liberation of gravitational energy from element sedimentation in the crystallizing cores5-7. Our results describe the energy released by crystallization in strongly coupled Coulomb plasmas8,9, and the measured cooling delays could help to improve the accuracy of methods used to determine the age of stellar populations from white dwarfs10. Photometry and parallax data from the Gaia satellite provide direct observational evidence of a theoretically predicted pile-up in the cooling sequence of white dwarfs, which is associated with core crystallization. [ABSTRACT FROM AUTHOR]

The significance and spectrum of reduced right ventricular (RV) deformation, reported in endurance athletes, is unclear. To comprehensively analyze the cardiac performance at rest of athletes, especially focusing on integrating RV size and deformation to unravel the underlying triggers of this ventricular remodelling. Hundred professional male athletes and 50 sedentary healthy males of similar age were prospectively studied. Conventional echocardiographic parameters of all four chambers were obtained, as well as 2D echo-derived strain (2DSE) in the left (LV) and in the RV free wall with separate additional analysis of the RV basal and apical segments. Left and right-sided dimensions were larger in athletes than in controls, but with a disproportionate RA enlargement. RV global strain was lower in sportsmen (-26.8 ± 2.8% vs -28.5 ± 3.4%, p < 0.001) due to a decrease in the basal segment (-22.8 ± 3.5% vs -25.8 ± 4.0%, p < 0.001) resulting in a marked gradient of deformation from the RV inlet towards the apex. By integrating size, deformation and stroke volume, we observed that the LV working conditions were similar in all sportsmen while a wider variability existed in the RV. Cardiac remodelling in athletes is more pronounced in the right heart cavities with specific regional differences within the right ventricle, but with a wide variability among individuals. The large inter-individual differences, as well as its acute and chronic relevance warrant further investigation. [ABSTRACT FROM AUTHOR]

Heart failure leads to gross cardiac structural changes. While cardiac resynchronization therapy (CRT) is a recognized treatment for restoring synchronous activation, it is not clear how changes in cardiac shape and size affect the electrical pacing therapy. This study used a human heart computer model which incorporated anatomical structures such as myofiber orientation and a Purkinje system (PS) to study how pacing affected failing hearts. The PS was modeled as a tree structure that reproduced its retrograde activation feature. In addition to a normal geometry, two cardiomyopathies were modeled: dilatation and hypertrophy. A biventricular pacing protocol was tested in the context of atrio-ventricular block. The contribution of the PS was examined by removing it, as well as by increasing endocardial conductivity. Results showed that retrograde conduction into the PS was a determining factor for achieving intraventricular synchrony. Omission of the PS led to an overestimate of the degree of electrical dyssynchrony while assessing CRT. The activation patterns for the three geometries showed local changes in the order of activation of the lateral wall in response to the same pacing strategy. These factors should be carefully considered when determining lead placement and optimizing device parameters in clinical practice. [ABSTRACT FROM AUTHOR]

Reconstructions of segmental diaphyseal bone defects with massive allografts are related to complications like nonunion and fractures. A reconstruction of these defects with a cage filled with an impacted morsellized bone graft could be an alternative. The bone graft in these cages should ideally be loaded to prevent resorption. Loading of morsellized bone grafts however can cause instability. The goal of this study was to assess the stability of an impacted morsellized bone graft in a cage under dynamic loaded conditions in an in vitro reconstruction of a segmental diaphyseal bone defect. The second goal was to assess the influence of cage type, washing of the graft and bone-cage fit. Two different cage types were filled with impacted morsellized bone graft. The grafts were used washed and unwashed and in variable bone-cage fit conditions. We recorded the bone graft deformation in the cage under dynamic loaded conditions. Stability appeared to be not very sensitive to the cage type and whether the bone chips were washed or not. However, quality of the fit of the cage with the bone segment was an important parameter and should be optimized during surgery. Morsellized impacted bone graft in a cage is stable in dynamic loaded conditions in an in vitro reconstruction of a segmental diaphyseal bone defect. We believe that this method of reconstruction is a promising alternative for the reconstruction of large diaphyseal bone defects and should be tested relative to its biological merits in animal experiments. [ABSTRACT FROM AUTHOR]

In a commutative Banach algebra B the set of logarithmic residues (i.e., the elements that can be written as a contour integral of the logarithmic derivative of an analytic B-valued function), the set of generalized idempotents (i.e., the elements that are annihilated by a polynomial with non-negative integer simple zeros), and the set of sums of idempotents are all the same. Also, these (coinciding) sets consist of isolated points only and are closed under the operations of addition and multiplication. Counterexamples show that the commutativity condition on B is essential. The results extend to logarithmic residues of meromorphic B-valued functions. [ABSTRACT FROM AUTHOR]

Let f be an analytic Banach algebra valued function and suppose that the contour integral of the logarithmic derivative f′f around a Cauchy domain D vanishes. Does it follow that f takes invertible values on all of D? For important classes of Banach algebras, the answer is positive. In general, however, it is negative. The counterexample showing this involves a (nontrivial) zero sum of logarithmic residues (that are in fact idempotents). The analysis of such zero sums leads to results about the convex cone generated by the logarithmic residues. [ABSTRACT FROM AUTHOR]

The problem treated in this paper is the following. Let p,..., p be idempotents in a Banach algebra B, and assume p+...+ p=0. Does it follow that p=0, j=1,..., k? For important classes of Banach algebras the answer turns out to be positive; in general, however, it is negative. A counterexample is given involving five nonzero bounded projections on infinite-dimensional separable Hilbert space. The number five is critical here: in Banach algebras nontrivial zero sums of four idempotents are impossible. In a purely algebraic context (no norm), the situation is different. There the critical number is four. [ABSTRACT FROM AUTHOR]

The Fredholm properties (index, kernel, image, etc.) of Wiener-Hopf integral operators are described in terms of realization of the symbol for a class of matrix symbols that are analytic on the real line but not at infinity. The realizations are given in terms of exponentially dichotomous operators. The results obtained give a complete analogue of the earlier results for rational symbols. [ABSTRACT FROM AUTHOR]

For Wiener-Hopf integral equations with an operator or matrix valued kernel and with an invertible symbol which is analytic on the real line and at infinity an indicator is introduced. In general this indicator is a bounded linear operator, but when the kernel is matrix valued and the symbol is rational it is a (possibly non-square) matrix. From the indicator the invertibility properties and Fredholm characteristics of the integral equation can be read off. The class of Wiener-Hopf equations studied here is also described in terms of growth conditions on the derivatives of the kernel. [ABSTRACT FROM AUTHOR]

This paper developes further the connections between linear systems and convolution equations. Here the emphasis is on equations on finite intervals. For these equations a new characteristic matrix (or operator) function is introduced, which contains all the important information about the equations and the corresponding operators. Explicit formulas for solutions and resolvent kernels are obtained. Convolution equations on the full line are also analyzed. Analogous results are derived for the inversion of finite and infinite Toeplitz matrices. [ABSTRACT FROM AUTHOR]

Let X be a Banach space, J $$ \subseteq $$ L(X) a Fréchet ideal and G a region in ℂ. If J is non-locally-convex, then it is a problem whether A ∈ H(G,L(X)), B ∈ H(G,J) implies A·B,B·A ∈ H(G,J). A positive answer to this question would sharpen an additive decomposition theorem of B. Gramsch [6] and B. Gramsch-W. Kaballo [8] for resolvents of semi-Fredholm functions. Here it is proved that if J is contained in another ideal J such that the inclusion map i : J → J is the product of N exponentially galbed maps in the sense of P. Turpin [18], [19], then A·B,B·A ∈ H(G,J). An example shows that this is false if i is only a product of N-1 exponentially galbed maps. Thus a sharpening of the decomposition result mentioned above is obtained. Finally, for N=1, a sharper version of a multiplicative decomposition theorem of G.Ph.A. Thijsse [17] for FG-meromorphic functions is proved. [ABSTRACT FROM AUTHOR]

The stable factorizations of a monic matrix polynomial are characterized in terms of spectral properties. Proofs are based on the divisibility theory developed by I. Gohberg, P. Lancaster and L. Rodman. A large part of the paper is devoted to a detailed analysis of stable invariant subspaces of a matrix. The results are also used to describe all stable solutions of the operator Riccati equation. [ABSTRACT FROM AUTHOR]

The main purpose is to introduce a new operator node and a new characteristic operator function. The node serves as a model for monic operator polynomials. [ABSTRACT FROM AUTHOR]

Immunoaffinity enrichment of proteotypic peptides, coupled with selected reaction monitoring, enables indirect protein quantification. However the lack of suitable antibodies limits its widespread application. We developed a method in which multi-specific antibodies are used to enrich groups of peptides, thus facilitating multiplexed quantitative protein assays. We tested this strategy in a pharmacokinetic experiment by targeting a group of homologous drug transforming proteins in human hepatocytes. Our results indicate the generic applicability of this method to any biological system. [ABSTRACT FROM AUTHOR]

Echocardiography has a leading role in the routine assessment and diagnosis of hypertrophic ventricles. However, the use of M-mode echocardiography and measurement of global left ventricular function may be misleading. Traditionally, systolic function was thought to be preserved in patients with hypertrophic myopathies until the late stages of the disease, and hypertrophic myopathies were thought to affect the myocardium more diffusely than ischemic heart disease. Ultrasound deformation imaging, either by Doppler myocardial imaging or speckle tracking, provides more-sensitive detection of regional myocardial motion and deformation than standard echocardiography. Basic and clinical studies that apply these techniques have revealed early, often subclinical impairment in systolic function. This information allows the detection and treatment of myocardial dysfunction at an early stage, which is of high clinical importance. Physiological hypertrophic remodeling seen in athletes differs from pathological myocardial hypertrophy, which can be caused by compensatory reactive hypertrophy owing to pressure overload in patients with aortic stenosis or hypertension, as well as amyloidosis, Fabry disease or Friedreich ataxia. Each of the etiologies associated with hypertrophy demonstrate distinct regional changes in myocardial deformation, which allows identification of the underlying processes, and will improve the assessment and follow-up of patients with hypertrophic myopathies. [ABSTRACT FROM AUTHOR]