Testing the Braneworld Theory with Identical Particles

Various attempts to go beyond the theory of General Relativity start from the assumption that spacetime is not a 4-dimensional but rather a higher-dimensional manifold. Among others, braneworld scenarios postulate that the spacetime we effectively observe is actually a 4-dimensional brane embedded in a higher-dimensional spacetime. In general, braneworld models predict a departure from the Newton gravity law in the nonrelativistic regime. Based on this fact, we propose an experimental test that uses a pair of gravitationally interacting identical particles to determine the validity of certain braneworld models and provide numerical results that should be compared with experimental data. In particular, we consider the Randal-Sundrum braneworld model and study two cases of 5-dimensional gravity theories: the Einstein-Hilbert gravity with the negative cosmological constant and the Einstein-Gauss-Bonnet (nearly-Chern-Simons) gravity.Comment: 6 pages, 6 figures, comments are welcom

Oestradiol Treatment Counteracts the Effect of Fructose-Rich Diet on Matrix Metalloproteinase 9 Expression and NF kappa B Activation

Fructose-rich diet induces metabolic changes similar to those observed in metabolic syndrome. Among other matrix metalloproteinases, MMP-9 has an important role in adverse cardiac remodelling and might have a role in the development of cardiovascular disorders associated with metabolic syndrome. The changes of MMP-9 expression could be mediated via the NF kappa B pathway. In this study we investigated the effect of fructose-rich diet on MMP-9 expression in the heart of male and female rats, along with the effect of fructose-rich diet and oestradiol on MMP-9 expression in ovariectomized females. We further assessed the effect of fructose-rich diet and oestradiol on NF kappa B activation, measured as the level of p65 phosphorylation at Ser 276. The results showed that the diet regime did not affect the heart mass. Higher MMP-9 gene expression was found in cardiac tissue of male rats fed the fructose-rich diet than in females on the same diet regime. In ovariectomized females, fructose-rich diet upregulated MMP-9 protein and mRNA expression in the heart, as well as phosphorylation of the p65 subunit of NF kappa B at Ser 276. Oestradiol replacement therapy reverted these changes in the heart of ovariectomized females. This study has shown that oestradiol could revert the early molecular changes in MMP-9 expression induced by fructose-rich diet that occurred before cardiac hypertrophy development by decreasing phosphorylation of the NF kappa B p65 subunit at Ser 276

Promene morfometrijskih parametara mastocita u srcu pacova akutno trovanih T-2 toksinom

Wistar rats were treated with T-2 toxin (1 LD50; 0.23 mg/kg sc) and the surviving animals were sacrificed on days 1, 3, 5, 7, 14, 21 and 28 after treatment. At each time, control animals were sacrificed, too. Cardiac mast cells, previously stained by Giemsa method, were analyzed in whole visual fields, magnification x40. In the present study the following quantitative morphometric parameters of cardiac mast cells were evaluated: perimeter (P), area (A) and roundness (R). In the control groups of rats the majority of mast cells were small (P = 6.86 - 7.99 mm), hypogranular (A = 11.60 -14.30 mm2) and ovoid (R = 0.60 - 0.65 mm). Mast cells, with discrete granules, hypergranular, had significantly different quantitative parameters (P = 12.80 -14.90 mm; A = 16.70 -20.00 mm2; R = 0.35 -0.38 mm). The minority of mast cells, classified as degranulated, had a large (P=20.70-23.30 mm), irregular shape (A = 24.40 -30.90 mm2) and showed degranulation (R = 0.15 - 0.21 mm). In the heart of T-2 toxin-treated rats the quantitative parametar values of hypogranular mast cells and hypergranular mast cells were similar to the control group during the whole study. However, degranulated mast cells showed a significant increase in perimeter and area values (p lt 0.05), while their roundness was decreased (p lt 0.05) in comparison to the control groups of animals. It could be concluded that the chosen quantitative morphometric parameters of cardiac degranular mast cells are useful for the evaluation of the functional status of the rats' heart during acute T-2 poisoning.Preživeli Wistar pacovi, tretirani T-2 toksinom (1 LD50; 0,23 mg/kg sc), žrtvovani su 1, 3, 5, 7, 14, 21. i 28. dana posle tretmana. U istim vremenskim intervalima žrtvovane su životinje iz kontrolnih grupa. Mastociti srca, prethodno obojeni primenom Giemsa metode bojenja, analizirani su u celom vidnom polju, pod uveličanjem 40. U ovom radu ispitivani su sledeći kvantitativni morfometrijski parametri: perimetar (P), površina (A) i kružnost (R). U srcu kontrolne grupe pacova mastocititi su većinom sitni (P = 6,86-7,99 mm), hipogranularni (A = 11,60 -14,30 mm2) i ovalnog oblika (R = 0,60-0,65 mm). Mastociti blago ispunjeni granulama, hipergranularni mastociti, imali su statistički značajno različite vrednosti kvantitativnih parametera (P = 12,80 -14,90 mm; A = 16,70 -20,00 mm2; R = 0,35-0,38 mm). Mali broj mastocita označeni kao deganulirani mastociti su veliki (P = 20,70-23,30 mm), nepravilnih oblika (A = 24,40 -30,90 mm2) sa granulama ispražnjenim u okolno tkivo (R = 0,15 -0,21 mm). U srcu pacova tretiranih T-2 toksinom kvantitativni parametari hipogranuliranih i hipergarnuliranih mastocita imali su vrednosti slične kontrolnim grupama životinja tokom celog perioda ispitivanja. Međutim, degranulirani mastociti pokazali su statistički značajno povećanje vrednosti prečnika i površine (p lt 0,05), dok je njihova kružnost bila manja (p lt 0,05) u poređenju sa kontrolnim grupama pacova. Moglo bi se zaključiti da su ispitivani kvantitativni morfometrijski parametri degranuliranih mastocita korisni za ispitivanje funkcionalnog statusa srca pacova akutno trovanih T-2 toksinom

Divovska kavernozna malformacija s neuobičajeno agresivnim kliničkim tijekom: prikaz slučaja

Giant cavernomas (GC) are rare lesions, with less than 50 cases reported so far. Clinical presentation usually involves epileptic seizures and less typically focal neurological deficit, due to repeated hemorrhages and GC mass effect and consequentially increased intracranial pressure. Although individual cases have been reported, due to the rarity and variable imaging appearance, GCs are usually not considered in the differential diagnosis of large hemorrhagic lesions, especially when significant mass effect is present. A 17-year-old boy presented due to severe headache, right-sided weakness, and slurred speech. Symptoms started three days before with occasional headaches, which intensified gradually. Emergency computed tomography revealed a left frontal massive heterogeneous lesion. Soon after, right-sided hemiparesis and speech impairment progressed, and the patient became drowsy with the slightly dilated left pupil. Emergency surgery was performed, and the lobed grayish lesion was entirely removed. Based on the macroscopic appearance, the surgeon assumed it was a metastasis of melanoma. Histopathologic analysis result was cavernoma. GC should be considered as an option in hemorrhagic lesions, especially in the young age population. Emergency surgery for mass lesions is not uncommon in neurosurgery; however, bleeding cavernomas are usually planned for elective surgery due to the specific approach and complications.Divovski kavernomi (DK) su rijetke lezije s manje od 50 dosad opisanih slučajeva. Uobičajena simptomatologija su epileptični napadaji, a rjeđe se manifestiraju žarišnim neurološkim deficitom koji je uzrokovan ponavljanim hemoragijama i posljedičnim povećanjem intrakranijskog tlaka. Iako su objavljeni pojedini slučajevi, zbog rijetke pojavnosti i raznovrsne radiološke prezentacije DK se obično ne razmatraju u diferencijalnoj dijagnostici velikih hemoragičnih ekspanzivnih lezija, pogotovo kada je prisutan značajan kompresivni učinak. Sedamnaestogodišnji dječak se javio liječniku zbog jake glavobolje, blaže desnostrane slabosti i nerazgovijetnog govora. Simtpomi su se javili 3 dana ranije u vidu blagih glavobolja koje su se postupno pojačavale. Hitna kompjutorizirana tomografija je pokazala masivnu hemoragičnu leziju frontalno lijevo. Nedugo zatim desnostrana slabost i nerazgovijetan govor su se pogoršali i bolesnik je postao pospan s blago proširenom lijevom zjenicom. Učinjena je hitna operacija, kružna sivkasta lezija je u cijelosti uklonjena. Na osnovi makroskopskog izgleda kirurg je pomislio da se radi o metastazi melanoma. Histopatološka analiza je pokazala da se radi o kavernomu. DK bi trebalo razmatrati kao mogućnost kod hemoragičnih lezija, pogotovo kod mlađih bolesnika. Hitna operacija kod kompresivnih lezija nije rijetkost u neurokirurgiji, međutim, krvareći kavernomi se obično planiraju za elektivnu operaciju zbog specifičnog pristupa i mogućih komplikacija

Ultradian oscillations of corticotropin-releasing hormone (crh) and arginine vasopressin (avp) in modelling of hypothalamic-pituitary-adrenal axis: influence of feedback loop between crh and cortisol

The previously proposed stoichiometric model of the Hypothalamic-Pituitary-Adrenal (HPA) axis activity that took into account arginine vasopressin (AVP), has been further developed to emulate ultradian oscillations of corticotropin-releasing hormone (CRH) and AVP. With this aim, additional coupling of HPA consisting hormones was introduced into this model by reaction between CRH and cortisol (CORT). How additional coupling of hormones affects HPA axis ultradian dynamics and reflects on ultradian oscillations of AVP and CRH concentrations was examined by using numerical simulations and bifurcation analysis. Results show that the rate constant of newly incorporated reaction alone is sufficient to be adjusted only for CRH to exhibit oscillations with optimally prominent amplitudes. Also, oscillation frequencies of CRH were found to be in accordance with findings in the literature under all investigated condition

Circadian rhythm function coupling to the upgraded hypothalamic-pituitary-adrenal (hpa) axis with incorporated arginine vasopressin

An upgraded model of the Hypothalamic-Pituitary-Adrenal (HPA) axis has been developed that advances our previously proposed low-dimensional HPA model by including the effects of arginine vasopressin (AVP) that is a key modulator of HPA axis function. The upgraded model allows us to emulate AVP effects on HPA axis dynamics individually and in synergy with the corticotropin-releasing hormone (CRH). In this work, we examine how coupling of the circadian function through summarised reaction steps describing CRH and AVP biosynthesis in the same neuronal cell group of the hypothalamic paraventricular nucleus (PVN) affects HPA axis dynamics. Results of numerical simulations show that coupling of the circadian function through both, CRH and AVP summarised biosynthesis reaction steps simultaneously, emulates best the HPA axis dynamics, in line with literature findings

Influence of arginine vasopressin on the ultradian dynamics of Hypothalamic-Pituitary-Adrenal axis

Numerous studies on humans and animals have indicated that the corticotrophin-releasing hormone (CRH) and arginine vasopressin (AVP) stimulate both individually and synergistically secretion of adrenocorticotropic hormone (ACTH) by corticotropic cells in anterior pituitary. With aim to characterize and better comprehend the mechanisms underlying the effects of AVP on Hypothalamic-Pituitary-Adrenal (HPA) axis ultradian dynamics, AVP is here incorporated into our previously proposed stoichiometric model of HPA axis in humans. This extended nonlinear network reaction model took into account AVP by: reaction steps associated with two separate inflows of AVP into pituitary portal system, that is synthesized and released from hypothalamic parvocellular and magnocellular neuronal populations, as well as summarized reaction steps related to its individual and synergistic action with CRH on corticotropic cells. To explore the properties of extended model and its capacity to emulate the effects of AVP, nonlinear dynamical systems theory and bifurcation analyses based on numerical simulations were utilized to determine the dependence of ultradian oscillations on rate constants of the inflows of CRH and AVP from parvocellular neuronal populations, the conditions under which dynamical transitions occur due to their synergistic action and, moreover, the types of these transitions. The results show that under certain conditions, HPA system could enter into oscillatory dynamic states from stable steady state and vice versa under the influence of synergy reaction rate constant. Transitions between these dynamical states were always through supercritical Andronov-Hopf bifurcation point. Also, results revealed the conditions under which amplitudes of ultradian oscillations could increase several-fold due to CRH and AVP synergistic stimulation of ACTH secretion in accordance with results reported in the literature. Moreover, results showed experimentally observed superiority of CRH as a stimulator of ACTH secretion compared to AVP in humans. The proposed model can be very useful in studies related to the role of AVP and its synergistic action with CRH in life-threatening circumstances such as acute homeostasis dynamic crisis, autoimmune inflammations or severe hypovolemia requiring instant or several-days sustained corticosteroid excess levels. Moreover, the model can be helpful for investigations of indirect AVP-induced HPA activity by exogenously administered AVP used in therapeutic treatment

Production systems and feeding of local breeds of pigs in Republic of Serbia

In recent years, the popularity of local pig breeds has increased in the Republic of Serbia. Local pig breeds such as Mangalitza, Moravka and Resavka, have again found their place in rural households and in the overall biodiversity of Serbia. Their increasing number led to a diversity of production systems and feeding types. They ranged from fully intensive systems with commercial mixtures to completely extensive without supplementing any additional feed except what the animals find on the ground. Aim of this study was to determine the differentiation of these systems by region and to examine the differences between them. We classified all these production systems into six categories: intensive systems using commercial mixtures, intensive systems using cereals, vegetables and fruits as the main feed, semi-intensive systems using commercial mixtures, semi-intensive systems using cereals, vegetables and fruits as the main feed, extensive systems using cereals, vegetables and fruits as supplemental feed and completely extensive systems. We studied the main advantages and disadvantages of these systems, including economic factors. The results showed extreme differences, especially in animal size, investment, and economic aspects. Contrary to wide opinion the lowest investments were on farms with fully intensive systems because they used old concrete buildings that were used for commercial breeds in the past. On the other hand, breeders with full extensive systems have made the most investments, considering the cost of the land. The size of the animals and the type of feed used were in positive correlation. Animals fed commercial mixtures were almost double in size and weight than those raised in fully extensive way. The cost of feed dictates which feeds are used in the animal’s diet, especially considering grains, vegetables, and fruits. Although the investment in fully intensive systems is lower, the health aspect and welfare of the animals in these systems should be studied. Besides the health aspect, it is questionable how these breeding systems affect the quality of the final products of these local breeds. Furthermore, it will be interesting to investigate how each of these breeds performs in all these production systems. Also, further studies will investigate how these types of production systems affect the value of the final pig products on the market

Carcass traits of Mangalitsa pigs - effect of immunocastration

This research was aimed at evaluating carcass differences between surgical and immunocastrated fatteners of Mangalitsa breed. The study comprised 23 male pigs kept under the identical managament conditions and divided in the two groups: surgically castrated (SC, n=11) and immunocastrated (IC, n=12). The animals were kept in a semi-outdoor system facility with open (100 m2) and covered (40 m2) part. Pigs under investigation were fed complete feed mixtures (15% and 13% of crude protein and 13.5 MJ ME/kg). Carcass traits measured on the slaughter line included: warm and cold carcass weight (kg), carcass length (cm), share of the main parts in half-carcasses (ham, loins, shoulder, rib-abdominal part; %), fat and longissimus dorsi muscle thickness (mm). Thickness of subcutaneous fat measured at three points; where m. gluteus medius gets deepest into the fat tissue; at the level of the first rib – between the last neck and the first thoracic vertebrae; at the level of the last rib – between the last thoracic and the first lumbar vertebrae. Muscle thickness measured from the end of the spinal column to the cranial part of the m. gluteus medius. At slaughter, SC and IC group of pigs had live weight of 116 and 121 kg, respectively (p>0.05). Warm and cold carcass weight in SC, compared to IC group, was higher by 2.2, i.e. 2.4 kg, respectively (p0.05). The fatteneres in the IC group had a higher share of carcass ham (11.4 vs. 9.9%, p0.05), respectively. The immunocastrated group had better carcass traits, considering that they had i higher share of ham in carcass and lower fat thickness

Fertility traits of sows by genotypes in C. Serbia

The aim of the research was to determine the fertility of purebred sows (Large White -LW, Landrace -L, Swedish Landrace -SL, Danish Landrace - DL, Duroc -D, Pietrain -P, Hampshire -H, Norwegian Landrace -NL, German Landrace -Ne.L.) and seven F1 hybrid genotypes (Landrace and Large White). The influence of genotype and parity of sows on litter size traits (Number of live born piglets -NLBP, number of stillborn piglets -NSP, total piglets born -TPB, number of reared piglets and litter weight) and lactation duration was examined. Research showed that the highest number of live born piglets was in F1 crossbreeds (13.36 NLBP), while among purebreds the highest NLBP was in the Landrace breed (12.44 NLBP) and Large White (12.17 NLBP). Looking at parities for all tested genotypes, NLBP in the first litter was over 11.53 piglets. For breed L and LW, the highest NLBP was in the fourth litter 12.88 and 12.55 piglets. F1 crosses LxLW (♀Lx♂LW) also had the highest NLBP in the fourth litter 12.85 piglets. For the genotype F1 crosses LWx L (♀LWx♂L), the highest average number of live-born piglets was 12.32 piglets in the second and third litters. Variation in litter size at birth and weaning by genotype and parity was statistically significant (P<0.01), except for the number of stillborn piglets of L sows by parity, where a significant difference was found (P<0.05)