Inhomogeneous Reionization Models in Cosmological Hydrodynamical Simulations

In this work we present a new hybrid method to simulate the thermal effects of the reionization in cosmological hydrodynamical simulations. The method improves upon the standard approach used in simulations of the intergalactic medium (IGM) and galaxy formation without a significant increase of the computational cost allowing for efficient exploration of the parameter space. The method uses a small set of phenomenological input parameters and combines a semi-numerical reionization model to solve for the topology of reionization and an approximate model of how reionization heats the IGM, with the massively parallel \texttt{Nyx} hydrodynamics code, specifically designed to solve for the structure of diffuse IGM gas. We have produced several large-scale high resolution cosmological hydrodynamical simulations ($2048^3$, $L_{\rm box} = 40$ Mpc/h) with different instantaneous and inhomogeneous HI reionization models that use this new methodology. We study the IGM thermal properties of these models and find that large scale temperature fluctuations extend well beyond the end of reionization. Analyzing the 1D flux power spectrum of these models, we find up to $\sim 50\%$ differences in the large scale properties (low modes, $k\lesssim0.01$ s/km) of the post-reionization power spectrum due to the thermal fluctuations. We show that these differences could allow one to distinguish between different reionization scenarios already with existing Ly$\alpha$ forest measurements. Finally, we explore the differences in the small-scale cutoff of the power spectrum and we find that, for the same heat input, models show very good agreement provided that the reionization redshift of the instantaneous reionization model happens at the midpoint of the inhomogeneous model.Comment: 24 pages, 16 figures. Accepted by MNRAS. Minor changes to match published versio

A New Measurement of the Temperature Density Relation of the IGM From Voigt Profile Fitting

We decompose the Lyman-{\alpha} (Ly{\alpha}) forest of an extensive sample of 74 high signal-to-noise ratio and high-resolution quasar spectra into a collection of Voigt profiles. Absorbers located near caustics in the peculiar velocity field have the smallest Doppler parameters, resulting in a low-$b$ cutoff in the $b$-$N_{\text{HI}}$ set by the thermal state of intergalactic medium (IGM). We fit this cutoff as a function of redshift over the range $2.0\leq z \leq 3.4$, which allows us to measure the evolution of the IGM temperature-density ($T= T_0 (\rho/ \rho_0)^{\gamma-1}$) relation parameters $T_0$ and $\gamma$. We calibrate our measurements against Ly$\alpha$ forest simulations, using 21 different thermal models of the IGM at each redshift, also allowing for different values of the IGM pressure smoothing scale. We adopt a forward-modeling approach and self-consistently apply the same algorithms to both data and simulations, propagating both statistical and modeling uncertainties via Monte Carlo. The redshift evolution of $T_0$ shows a suggestive peak at $z=2.8$, while our evolution of $\gamma$ is consistent with $\gamma\simeq 1.4$ and disfavors inverted temperature-density relations. Our measured evolution of $T_0$ and $\gamma$ are generally in good agreement with previous determinations in the literature. Both the peak in the evolution of $T_0$ at $z = 2.8$, as well as the high temperatures $T_0\simeq 15000-20000\,$K that we observe at $2.4 < z < 3.4$, strongly suggest that a significant episode of heating occurred after the end of HI reionization, which was most likely the cosmic reionization of HeII.Comment: Accepted for publication in ApJ, 23 pages, 26 figures, machine readable tables available onlin

Analysis of metabolic determinants of arterial hypertension in overweight type 2 diabetic patients

Arterijska hipertenzija (AH) je dva puta češća kod pacijenta sa tipom 2 dijabetesa (T2D), dok se prisustvo insulinske rezistencije smatra jednim od mogućih metaboličkih poremećaja koji povezuje ova dva klinička stanja. Ostali faktori rizika kao što su visceralna i ukupna gojaznost, hiperinsulinemija, hronična inflamacija, hiperglikemija, dislipidemija, pušenje i godine starosti, takođe doprinose pojavi AH kod pacijenata sa T2D. Polazeći od saznanja da je sniženi nivo insulinske senzitivnosti značajan faktor rizika za nastanak AH, ali da detaljni mehanizmi kojima poremećena insulinska senzitivnost ostvaruje svoj uticaj u T2D nisu razjašnjeni, u ovoj doktorskoj tezi je postavljen cilj da se ispita povezanost prisustva AH sa stepenom insulinske rezistencije, izmenjenim metabolizmom lipoproteina, poremećajem nivoa adipocitokina, pro- inflamatornih markera, izmenjenim antioksidatnim statusom i markera endotelne disfunkcije kod gojaznih pacijenata sa T2D. Na osnovu definisanog cilja, postavljeni su sledeći istraživački zadaci: (1) utvrditi povezanost insulinske rezistencije i AH kod pacijenata sa T2D; (2) ispitati odnos insulinske rezistencije, stepena ukupne i visceralne gojaznosti i prisustva AH kod pacijenata sa T2D; (3) utvrditi povezanost insulinske rezistencije, nivoa adipocitokina i prisustva AH kod pacijenata sa T2D; (4) analizirati povezanost insulinske rezistencije, lipidskih parametara i AH kod pacijenata sa T2D; (5) analizirati povezanost insulinske rezistencije, parametara inflamacije i prisustva AH kod pacijenata sa T2D; (6) proučiti povezanost insulinske rezistencije, nivoa antioksidantnog statusa i prisustva AH kod pacijenata sa T2D i (7) ispitati odnos insulinske rezistencije i markera endotelne disfunkcije i prisustva AH kod pacijenata sa T2D. U istraživanje u okviru ove doktorske disertacije uključeno je ukupno 80 ispitanika, oba pola, starosti 40-70 godina, koji su svrstani u sledeće grupe: 30 ispitanika sa T2D, gojaznošću i AH (grupa A), 9 ispitanika sa T2D, gojaznošću bez AH (grupa B), 14 ispitanika sa T2D bez gojaznosti sa AH (grupa C), 12 ispitanika sa T2D bez gojaznosti i bez AH (grupa D) i 15 ispitanika koji su činili zdravu kontrolu (grupa E)...Arterial hypertension (AH) is two times more frequent in patients with type 2 diabetes (T2D), while the presence of insulin resistance is one of the possible metabolic disorders, which connects these two clinical conditions. Other risk factors such as total and visceral obesity, hyperinsulinemia, chronic inflammation, hyperglycemia, dyslipidemia, smoking and age, also contribute to the appearance AH in T2D patients. Starting from the knowledge that the reduced level of insulin sensitivity signify risk factor for AH, but that the detailed mechanisms by which impaired insulin sensitivity exerts its influence in T2D have not yet been clarified aim of this thesis was to study the relationship between the presence of AH with the degree of insulin resistance, altered lipoprotein metabolism, disturbance levels of adipocytokines, pro - inflammatory cytokines, changed antioxidant status and markers of endothelial dysfunction in obese T2D patients. The research for this dissertation included a total of 80 subjects both sexes, aged 40-70 years, who were divided into the following groups: 30 patients with T2D, obesity and AH (group A), 9 patients with T2D, obesity without AH (group B), 14 patients with T2D without obesity and AH (group C), 12 patients with T2D without obesity and without AH (group D) and 15 healthy control subjects (group E). The selection of subjects was carried out according to the set tasks of research with the prior informed consent of the patient. Insulin levels, the degree of glycaemic control as well as the level of total cholesterol, its subfractions, triglycerides and apolipoproteins, free fatty acids (FFA), the parameters of inflammation (C - reactive protein (CRP) and fibrinogen), and then the levels of adipocytokines (adiponectin, resistin and leptin), proinflammatory cytokines (Tumor Necrosis Factor ( TNF ) - alpha, and interleukin ( IL ) -6), the level of antioxidant status (level of glutathione peroxidase (GSH - PX), superoxide dismutase (SOD) and total antioxidant status), and markers of endothelial dysfunction (nitric oxide (NO) and nitric oxide synthase (NOS) - a) were determined by standard methods in clearly defined terms for each of the subjects..

Properties and Use of a Lead Cathode at Very Negative Potential

The properties of lead cathodes at a very negative potential were studied on the basis of recent reports. The effects of the following factors on the »cathodic corrosion « of lead as well as on the preparative reduction of cyclohexanone as a test substance at lead cathode were investigated: the charge, current density, electrolyte composition, kind of the lead foil with respect to lead purity. The results of preparative electroreductions using both mercury and lead cathodes in identical reaction conditions were compared and discussed with regard to more practical aspects of their realization. The relation between the results obtained for the »cathodic corrosion« and for the overall cathode reaction at a lead cathode was also discussed. It was presumed that the overall reduction of cyclohexanone in the reaction conditions described in the paper (constant current density) consisted of two competitive reactions: a minor part of direct electron transfer and a predominant part of an indirect reduction using tetraalkylammonium lead

Inhomogeneous reionization models in cosmological hydrodynamical simulations

In this work we present a new hybrid method to simulate the thermal effects of reionization in cosmological hydrodynamical simulations. The method improves upon the standard approach used in simulations of the intergalactic medium (IGM) and galaxy formation without a significant increase in the computational cost, thereby allowing for efficient exploration of the parameter space. The method uses a small set of phenomenological input parameters, and combines a seminumerical reionization model to solve for the topology of reionization with an approximate model of how reionization heats the IGM, using the massively parallel Nyx hydrodynamics code which is specifically designed to solve for the structure of diffuse IGM gas. We have produced several medium-scale, high-resolution simulations (20483, Lbox = 40 Mpc h-1) with various instantaneous and inhomogeneous ${\rm H\,{\small I}}$ reionization models that use this new methodology. We study the IGM thermal properties of these models and find that large-scale temperature fluctuations extend well beyond the end of reionization. By analysing the 1D flux power spectrum of these models, we find up to {\sim } 50{{\\rm per\cent}} differences in the large-scale properties (low modes, k ≲0.01 s km-1) of the post-reionization power spectrum as a result of the thermal fluctuations. We show that these differences could allow one to distinguish between different reionization scenarios with existing Lyα forest measurements. Finally, we explore the differences in the small-scale cut-off of the power spectrum, finding that, for the same heat input, models show very good agreement provided that the reionization redshift of the instantaneous reionization model occurs at the midpoint of the inhomogeneous model

The Effect of Raw Soybeans in Mixtures for Laying Hens on Egg Quality and Egg Shell Quality

The study was conducted on hens at the age of 49 - 57 weeks to identify opportunities for replacing, with raw grain, thermally processed soybean Lana variety with a reduced level and Lydia variety with a standard level of trypsin inhibitor. The effect of using different levels of participation of both varieties of raw soybean in mixtures for layers on egg quality and eggshell quality was examined. The research was conducted according to the principle of two-factorial experiment (2 varieties x 4 levels of participation of raw soybeans). The average values of properties of the external and internal egg quality were under statistically significant influence of the level of participation of raw soybean in the mixture. Share of 8 % of raw soybeans of both varieties in diets for layers influenced significantly lower eggshape index, albumen height and Haugh's unit in relation to the mixture with a lower level of participation of raw soybeans. Yolk color and eggshell firmness were not significantly influenced by the studied factors

Dielectronic Recombination of Fe XV forming Fe XIV: Laboratory Measurements and Theoretical Calculations

We have measured resonance strengths and energies for dielectronic recombination (DR) of Mg-like Fe XV forming Al-like Fe XIV via N=3 -> N' = 3 core excitations in the electron-ion collision energy range 0-45 eV. All measurements were carried out using the heavy-ion Test Storage Ring at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. We have also carried out new multiconfiguration Breit-Pauli (MCBP) calculations using the AUTOSTRUCTURE code. For electron-ion collision energies < 25 eV we find poor agreement between our experimental and theoretical resonance energies and strengths. From 25 to 42 eV we find good agreement between the two for resonance energies. But in this energy range the theoretical resonance strengths are ~ 31% larger than the experimental results. This is larger than our estimated total experimental uncertainty in this energy range of +/- 26% (at a 90% confidence level). Above 42 eV the difference in the shape between the calculated and measured 3s3p(^1P_1)nl DR series limit we attribute partly to the nl dependence of the detection probabilities of high Rydberg states in the experiment. We have used our measurements, supplemented by our AUTOSTRUCTURE calculations, to produce a Maxwellian-averaged 3 -> 3 DR rate coefficient for Fe XV forming Fe XIV. The resulting rate coefficient is estimated to be accurate to better than +/- 29% (at a 90% confidence level) for k_BT_e > 1 eV. At temperatures of k_BT_e ~ 2.5-15 eV, where Fe XV is predicted to form in photoionized plasmas, significant discrepancies are found between our experimentally-derived rate coefficient and previously published theoretical results. Our new MCBP plasma rate coefficient is 19-28% smaller than our experimental results over this temperature range

Effects of rearing system and body weight of Redbro broilers on the frequency and severity of footpad dermatitis

High market demand for high-quality chicken paws, as well as their role in the assessment of the welfare of broiler chickens are the main reasons for the research in this area. In order to determine the effects of rearing system and the body weight of moderate growing broilers on the frequency and severity of incidence of footpad dermatitis, experimental research was conducted on a total of 300 Redbro chickens reared in free range and floor system in the production facility until the age of 84 days. Based on an individual weighing of broilers and visual evaluation of the incidence and severity of footpad lesions at the end of the experiment, the frequency of the individual scores for footpad dermatitis was determined, as well as the average score in each of the five weight groups. The effect of body weight on the incidence and severity of footpad dermatitis was not statistically confirmed, but the absence of the most difficult forms of footpad dermatitis in broiler group with the lowest body weight was recorded. Rearing broiler chickens in free range system manifested a positive effect in terms of increased frequency of broilers without lesions and less frequency of moderate and severe lesions in relation to rearing system in the production facility. Also, the effect of rearing system on the frequency of the most severe degree of dermatitis in broilers Redbro was statistically confirmed

Efekat upotrebe sirove soje u smešama za ishranu kokoši nosilja na proizvodne rezultate i relativnu masu pankreasa

The study was conducted on Isa Brown hybrid hens at the age of 49-57 weeks. The effect of using different levels of share of raw soybean of two varieties in mixtures for feeding hens on egg production, body weight, food consumption, the occurrence of defective eggs, mortality and the relative weight of the pancreas was studied. The possibility of replacing the heat-treated soybean grains, varieties Lana, with reduced trypsin inhibitor (TI) and Lydia with a standard level of TI, with raw soybean grains was examined. The research was conducted on the principle of two factorial experiment 2 x 4 (2 varieties x 4 levels of share of raw grain in the mixture) with a total of 8 diet treatments and 4 replicates per each treatment. In the first 5 weeks of the study, the differences in the number of eggs produced under the influence of tested factors were not significant. Under the influence of soybean varieties, the level of share of raw soybean and interaction of the studied factors showed significant differences (p lt 0.01) after 53 week of age. The use of soy with lower TI in the diet for laying hens resulted in a significantly greater capacity compared to standard variety. The share of raw soybean grains of 8 % in the mixtures significantly reduced the number of eggs laid. The differences in body weights, food consumption, occurrence of defective eggs and the relative weight of the pancreas were not significantly influenced by the studied factors or by their interaction effect.Cilj ovih istraživanja je bio da se ispitaju mogućnosti zamene termički obrađenog sojinog zrna, sorte Lana sa smanjenim sadržajem tripsin inhibitora (TI) i sorte Lidija sa standardnim nivoom TI, sirovim zrnom. Ispitan je efekat korišćenja različitog nivoa učešća sirove soje obe sorte u smešama za ishranu kokoši nosilja hibrida Isa Brown na proizvodnju jaja, telesne mase, konzumaciju hrane, pojavu defektnih jaja, mortalitet i relativnu masu pankreasa. Istraživanje je izvedeno po principu dvofaktorijalnog ogleda 2 x 4 (2 sorte soje x 4 nivoa učešća sirovog zrna u smeši) sa ukupno 8 tretmana ishrane i 4 ponavljanja po tretmanu. U prvih 5 nedelja ispitivanja razlike u broju ukupno snešenih jaja pod uticajem ispitivanih faktora nisu bile značajne. Pod uticajem sorte soje, nivoa učešća sirovog sojinog zrna i interakcije ispitivanih faktora utvrđene su značajne razlike (p lt 0,01) nakon 53. nedelje uzrasta. Korišćenje soje sa nižim nivoom TI u ishrani nosilja uticalo je na značajno bolju nosivost u odnosu na standardnu sortu soje. Sa učešćem sirovog sojinog zrna od 8 % u smešama značajno se smanjio broj ukupno snešenih jaja. Razlike u ostvarenim telesnim masama, konzumaciji hrane, pojavi defektnih jaja i relativnoj masi pankreasa koje su se javile nisu bile pod značajnim uticajem ispitivanih faktora kao ni pod uticajem njihovog interakcijskog dejstva

Fungal contamination and natural occurrence of ochratoxin A (OTA) in poultry feed

Total fungal count, the presence of potentially toxigenic fungi and natural occurrence of ochratoxin A (OTA) were studied in 30 poultry feed samples (14 samples of feed for chickens and 16 samples of feed for laying hens), which were collected from different farms in Serbia at the beginning of year 2014. The total number of fungi was determined by the method of dilution and OTA was detected using the imunoadsorption enzymatic assay (ELISA). In most of the samples of chickens feed (50%) the total number of fungi was 1 - 3 x 102 CFU g-1, and in feed for laying hens the highest number of samples (37.50%) had the total fungal count from 1.4 to 4.8 x 104 CFU g -1. The species of genera Aspergillus and Pénicillium were identified as producers of OTA in 21.43% and 42.86% of chickens feed samples and in 68.75% and 25% of samples of feed for laying hens. The presence of OTA was detected in 100% of samples of feed for chickens and laying hens, with average concentrations of 34.40 μg kg-1 (feed for chickens) and 43.89 μg kg-1 (feed for laying hens). The total fungal count and content of OTA were not above the maximum allowed quantities, even though the presence of Aspergillus and Penicillium species was found in a large number of samples (up to 68.75%). These results indicate that the tested samples of poultry feed were mycologically and mycotoxicologically correct