An XML format for benchmarks in High School Timetabling

The High School Timetabling Problem is amongst the most widely used timetabling problems. This problem has varying structures in different high schools even within the same country or educational system. Due to lack of standard benchmarks and data formats this problem has been studied less than other timetabling problems in the literature. In this paper we describe the High School Timetabling Problem in several countries in order to find a common set of constraints and objectives. Our main goal is to provide exchangeable benchmarks for this problem. To achieve this we propose a standard data format suitable for different countries and educational systems, defined by an XML schema. The schema and datasets are available online

PERUBAHAN RETENSI AIR PADA ZONE PERAKARAN TANAMAN JAGUNG AKIBAT APLIKASI BAHAN ORGANIK ECENG GONDOK (EICHORNIA CRASSIPES)

Management system implemented aimed to preventing land degradation and improve water availability in the rooting zone of Zea mays plantation. Increased availability of high water as inplikasi ability of organic matter in binding water. The research method using field experiments with Completely Random Design with five levels, ie, P0 = without Eichornia crassipess organic matter or control, P1 = 3 ton.ha-1 E. crassipess organic matter, P2 = 6 ton.ha-1 E. crassipess organic matter, P3 = 9 ton.ha-1 E. crassipess organic matter, and P4 = 12 ton.ha-1 E. crassipess organic matter. The results obtained showed that the treatment of E. crassipess organic matter 12 ton ha-1 can increase water retention at pF pF 1.00 and 2.00 times respectively at 1.19 and 1.17 times larger compared with the untreated organic matter (P0). Key words: E. crassipess, water retention, Zea may

Does experience in prehospital post-resuscitation critical care affect outcomes? A retrospective cohort study

Aims of the study: Helicopter Emergency Medical Services (HEMS) often provide post-resuscitation care. Our aims were to investigate whether physicians' frequent exposure to prehospital post-resuscitation care is associated with differences in (1) medical management, (2) achieving treatment targets recommended by resuscitation guidelines, (3) survival. Methods: We conducted a retrospective cohort study using data from a national HEMS quality register. We included patients between January 1st, 2012 and September 9th, 2019 who received post-resuscitation care by a HEMS physician. We excluded patients 12 cases). Medical management and proportions within treatment targets were compared. Survival at 30-days and 1-year was analysed by multivariate logistic regression analysis, controlling for known prognostic factors. Results: 2272 patients were analysed. Patients in the high exposure group had mechanical ventilation and vasoactive medications initiated more often (P < 0.001 and P = 0.008, respectively) and on-scene times were longer (P < 0.001). The target for blood pressure was achieved more often in this group (P = 0.026), but targets for oxygenation and ventilation were not. We did not see an association between survival and physicians' exposure to post-resuscitation care (odds ratio 0.96, 95% confidence interval 0.70-1.33 for low and 0.78, 0.56-1.08 for intermediate, compared to high exposure). Conclusions: Physicians with more, frequent exposure take a more active approach to post-resuscitation care, but this does not seem to improve survival.Peer reviewe

Covariant generalization of cosmological perturbation theory

We present an approach to cosmological perturbations based on a covariant perturbative expansion between two worldlines in the real inhomogeneous universe. As an application, at an arbitrary order we define an exact scalar quantity which describes the inhomogeneities in the number of e-folds on uniform density hypersurfaces and which is conserved on all scales for a barotropic ideal fluid. We derive a compact form for its conservation equation at all orders and assign it a simple physical interpretation. To make a comparison with the standard perturbation theory, we develop a method to construct gauge-invariant quantities in a coordinate system at arbitrary order, which we apply to derive the form of the n-th order perturbation in the number of e-folds on uniform density hypersurfaces and its exact evolution equation. On large scales, this provides the gauge-invariant expression for the curvature perturbation on uniform density hypersurfaces and its evolution equation at any order.Comment: Minor changes to match the version published in PRD. RevTex, 22 pages, 1 figur

Low-level liquid scintillation spectrometer for ß-counting

A new liquid scintillation (LS) spectrometer has been developed. lt improves the signal to noise ratio of C-14 assays by an order of magnitude compared to conventional LS systems. As a result, precision for a modern sample is 0.2 % and the dating limit is 64 Ky BP for a 15 ml sample of benzene. Sophisticated MCA facilities allow the use of Multiparameter Multichannel Analysis for data validation and age evaluation. Despite the high sophistication, the spectrometer, (named QUANTULUS) is seif contained, microprocessor controlled and user friendly. lt can be used with full advantage in a normal laboratory environment

Apical periodontitis associates with cardiovascular diseases : a cross-sectional study from Sweden

Background: Periodontal disease associates with systemic diseases but corresponding links regarding apical periodontitis (AP) are not so clear. Hence our aim was to study association between AP and the prevalence of systemic diseases in a study population from Sweden. Methods: The subjects were 150 patients from a randomly selected epidemiological sample of 1676 individuals. 120 accepted to participate and their basic and clinical examination data were available for these secondary analyses where dental radiographs were used to record signs for endodontic treatments and AP. Periapical Index and modified Total Dental Index scores were calculated from the x-rays to classify the severity of AP and dental infection burden, respectively. Demographic and hospital record data were collected from the Swedish National Statistics Center. T-test, chi-square and univariate analysis of covariance (ANCOVA) and regressions analyses were used for statistics. Results: Of the 120 patients 41% had AP and 61% had received endodontic treatments of which 52% were radiographically unsatisfactory. AP patients were older and half of them were smokers. AP and periodontitis often appeared in the same patient (32.5%). From all hospital diagnoses, cardiovascular diseases (CVD) were most common, showing 20.4% prevalence in AP patients. Regression analyses, controlled for age, gender, income, smoking and periodontitis, showed AP to associate with CVD with odds ratio 3.83 (95% confidence interval 1.18-12.40; p = 0.025). Conclusions: The results confirmed our hypothesis by showing that AP statistically associated with cardiovascular diseases. The finding that subjects with AP also often had periodontitis indicates an increased oral inflammatory burden.Peer reviewe

On the divergences of inflationary superhorizon perturbations

We discuss the infrared divergences that appear to plague cosmological perturbation theory. We show that within the stochastic framework they are regulated by eternal inflation so that the theory predicts finite fluctuations. Using the $\Delta N$ formalism to one loop, we demonstrate that the infrared modes can be absorbed into additive constants and the coefficients of the diagrammatic expansion for the connected parts of two and three-point functions of the curvature perturbation. As a result, the use of any infrared cutoff below the scale of eternal inflation is permitted, provided that the background fields are appropriately redefined. The natural choice for the infrared cutoff would of course be the present horizon; other choices manifest themselves in the running of the correlators. We also demonstrate that it is possible to define observables that are renormalization group invariant. As an example, we derive a non-perturbative, infrared finite and renormalization point independent relation between the two-point correlators of the curvature perturbation for the case of the free single field.Comment: 12 page

Non-Gaussianity in Curvaton Models with Nearly Quadratic Potential

We consider curvaton models with potentials that depart slightly from the quadratic form. We show that although such a small departure does not modify significantly the Gaussian part of the curvature perturbation, it can have a pronounced effect on the level of non-Gaussianity. We find that unlike in the quadratic case, the limit of small non-Gaussianity, $|f_{NL}|\ll1$, is quite possible even with small curvaton energy density $r\ll1$ . Furthermore, non-Gaussianity does not imply any strict bounds on $r$ but the bounds depend on the assumptions about the higher order terms in the curvaton potential.Comment: 11 pages, 3 figures. Minor changes. Typos corrected and a reference adde