Void Scaling and Void Profiles in CDM Models

An analysis of voids using cosmological N-body simulations of cold dark matter models is presented. It employs a robust statistics of voids, that was recently applied to discriminate between data from the Las Campanas Redshift Survey and different cosmological models. Here we extend the analysis to 3D and show that typical void sizes D in the simulated galaxy samples obey a linear scaling relation with the mean galaxy separation lambda: D=D_0+nu*lambda. It has the same slope nu as in 2D, but with lower absolute void sizes. The scaling relation is able to discriminate between different cosmologies. For the best standard LCDM model, the slope of the scaling relation for voids in the dark matter halos is too steep as compared to the LCRS, with too small void sizes for well sampled data sets. The scaling relation of voids for dark matter halos with increasing mass thresholds is even steeper than that for samples of galaxy-mass halos where we sparse sample the data. This shows the stronger clustering of more massive halos. Further, we find a correlation of the void size to its central and environmental average density. While there is little sign of an evolution in samples of small DM halos with v_{circ} ~ 90 km/s, voids in halos with circular velocity over 200 km/s are larger at redshift z = 3 due to the smaller halo number density. The flow of dark matter from the underdense to overdense regions in an early established network of large scale structure is also imprinted in the evolution of the density profiles with a relative density decrease in void centers by 0.18 per redshift unit between z=3 and z=0.Comment: 12 pages, 9 eps figures, submitted to MNRA

Voids in the LCRS versus CDM Models

We have analyzed the distribution of void sizes in the two-dimensional slices of the Las Campanas Redshift Survey (LCRS). Fourteen volume-limited subsamples were extracted from the six slices to cover a large part of the survey and to test the robustness of the results against cosmic variance. Thirteen samples were randomly culled to produce homogeneously selected samples. We then studied the relationship between the cumulative area covered by voids and the void size as a property of the void hierarchy. We find that the distribution of void sizes scales with the mean galaxy separation, $\lambda$. In particular, we find that the size of voids covering half of the area is given by D_{med} \approx \lambda + (12\pm3) \h^{-2}Mpc. Next, by employing an environmental density threshold criterion to identify mock galaxies, we were able to extend this analysis to mock samples from dynamical $n$-body simulations of Cold Dark Matter (CDM) models. To reproduce the observed void statistics, overdensity thresholds of $\delta_{th} \approx 0 ... 1$ are necessary. We have compared standard (SCDM), open (OCDM), vacuum energy dominated ($\Lambda$CDM), and broken scale invariant CDM models (BCDM): we find that both the void coverage distribution and the two-point correlation function provide important and complementary information on the large-scale matter distribution. The dependence of the void statistics on the threshold criterion for the mock galaxy indentification shows that the galaxy biasing is more crucial for the void size distribution than are differences between the cosmological models.Comment: 10 pages, 8 eps figures, submitted to MNRA

Survey of hydatid cyst surgeries in hospitals affiliated to Ahvaz Jundishapur University of Medical Sciences during 2004 to 2014

Background: Hydatidosis is one of the most important zoonotic diseases with global distribution. Due to the prevalence of the disease in country, the study aimed to determine the clinical and laboratory findings in patients with hydatidosis admitted to surgical departments of educational hospitals, Imam Khomeini and Golestan, in Ahvaz city during 2004-2014. Materials and Methods: Data of the patients including demographic characteristics, and clinical and laboratory findings were recorded in a prepared form and analyzed using descriptive statistics and Chi-square tests by the SPSS software. Results: From a total of all patients, 49 (55.7) and 39 patients (44.3) were females and males respectively; 25 patients were resident in rural areas and 62 in urban areas. The mean age of the patients was 30.6±2 years. Also, the maximum and minimum percentages of the disease were observed in the age group 20-29 and 80-89, respectively. Recurrence was observed in 9 patients. The highest prevalence of the hydatid cyst was in the right lobe of the liver (26.1). Among the methods of imaging, sonography and MRI had the highest and lowest use in the diagnosis of the disease, respectively. Conclusion: Findings of this study show that the most common organs affected are the liver and the younger age group and suburbs are more prone to hydatidosis. Due to the chronicity of the disease and the late diagnosis during the visit, screening for endemic areas and high-risk persons is recommended

Non-universality of elastic exponents in random bond-bending networks

We numerically investigate the rigidity percolation transition in two-dimensional flexible, random rod networks with freely rotating cross-links. Near the transition, networks are dominated by bending modes and the elastic modulii vanish with an exponent f=3.0\pm0.2, in contrast with central force percolation which shares the same geometric exponents. This indicates that universality for geometric quantities does not imply universality for elastic ones. The implications of this result for actin-fiber networks is discussed.Comment: 4 pages, 3 figures, minor clarifications and amendments. To appear in PRE Rap. Com

Chitosan-titanium dioxide-glucantime nanoassemblies effects on promastigote and amastigote of Leishmania major

The purpose of the present study was to design nanoassemblies of chitosan-titanium dioxide (TiO2) nanoparticles (NPs) loaded with glucantime for using their synergistic effects and enhancing the toxic effects of glucantime on Leishmania parasites. The nanoassemblies were prepared by electrostatic interactions and optimized by a response surface central composite design. The effects of glucantime, chitosan and TiO2 NPs amounts were studied on the particle size, zeta potential, loading efficiency, and release efficiency of drug from nanoassemblies. The conjugation of TiO2/chitosan-glucantime was verified by UV spectroscopy and changes in surface charge of NPs. The anti-promastigots effect of glucantime loaded in TiO2/chitosan nanoassemblies was studied by tripan blue dye test and their anti-amastigotes effect by counting the average number of parasites per infected J774 macrophages in 100 cells. The optimized formulation obtained by using 12.5 mg glucantime, 25 mg chitosan and 6 mg TiO2 NPs. Although TiO2 NPs alone were effective more than negative control in reduction of promastigots and amastigotes but they didn't show significant difference compared with free glucantime (p > 0.05). However, at the concentration of 50 μg/mL and after 72 h exposure nanoassemblies decreased the proliferation of L. major promastigotes and amastigotes 13 and 4-fold, respectively compared with glucantime alone. © 2017 Elsevier B.V

Genetic variation of Giardia lamblia isolates from food-handlers in Kashan, Central Iran

<p><strong><em>Background:</em></strong> Based on genotyping study of human isolates of <em>Giardia lamblia</em>; humans are mainly infected by two assemblages A and B. The present study was carried out to determine the sub-assemblages of <em>G. lamblia</em> isolated from food handlers referred to Kashan health centers, central Iran, 2015.</p><p><strong><em>Methods:</em></strong> In this cross-sectional<strong> </strong>study,<strong> </strong>3653 stool samples collected from food-handlers that annually refer to health center for getting a health certification and examined microscopically for <em>G. lamblia</em> cyst. Totally, 44 isolates were selected from 47 <em>Giardia</em> positive samples. Cysts were partially purified by the sucrose density gradient method. After freeze-thaw cycles, genomic DNA was extracted using QIAamp Stool Mini kit. A single step PCR-RFLP method was used to amplify a 458bp fragment at the glutamate dehydrogenase <em>(gdh</em>) locus, restriction enzymes <em>BspLI </em>and <em>RsaI</em> were used for distinguish between genotypes A and B and their subgroups.</p><p><strong><em>Results:</em></strong> Of 44 isolates, 24(54.5%) were sub-assemblage AII, 9(20.5%) group B including 7(15.9%) BIII and 2(4.6%) BIV sub-assemblage and 11(25%) isolates showed a mixed pattern of AII and B. Sub-assemblage AI was not detected in this study.</p><strong><em>Conclusion:</em></strong> The higher rate of sub-assemblage AII demonstrated an anthroponotic origin of the infection so infected food-handlers could directly transmit this protozoan to consumers via contaminated food and water. For finding of pattern of transmission and distribution of <em>Giardia</em> assemblages and sub-assemblage, more studies in human and animal population in different regions are necessary

Infinite-cluster geometry in central-force networks

We show that the infinite percolating cluster (with density P_inf) of central-force networks is composed of: a fractal stress-bearing backbone (Pb) and; rigid but unstressed ``dangling ends'' which occupy a finite volume-fraction of the lattice (Pd). Near the rigidity threshold pc, there is then a first-order transition in P_inf = Pd + Pb, while Pb is second-order with exponent Beta'. A new mean field theory shows Beta'(mf)=1/2, while simulations of triangular lattices give Beta'_tr = 0.255 +/- 0.03.Comment: 6 pages, 4 figures, uses epsfig. Accepted for publication in Physical Review Letter

Stressed backbone and elasticity of random central-force systems

We use a new algorithm to find the stress-carrying backbone of ``generic'' site-diluted triangular lattices of up to 10^6 sites. Generic lattices can be made by randomly displacing the sites of a regular lattice. The percolation threshold is Pc=0.6975 +/- 0.0003, the correlation length exponent \nu =1.16 +/- 0.03 and the fractal dimension of the backbone Db=1.78 +/- 0.02. The number of ``critical bonds'' (if you remove them rigidity is lost) on the backbone scales as L^{x}, with x=0.85 +/- 0.05. The Young's modulus is also calculated.Comment: 5 pages, 5 figures, uses epsfi

Effect of Estradiol and Soy Extract on the Onset of PTZ-Induced Seizure in Ovariectomized Rats: Implications for Nurses and Midwives

Background: In many epileptic women, the ovarian cycle influences the risk and severity of seizures. Previous studies have reported inconsistent findings regarding the neural excitatory effects of estrogen. Soybean is a rich source of plant estrogens. Therefore, soy intake can affect the risk and severity of seizures in women. Nurses and midwives need to be aware of the effects of diets containing estrogen in pregnant and post-menopausal women, as well as during the sexual cycle periods. Objectives: Due to the limitations of human studies, this study aimed to investigate the effect of estradiol and soy extract on the onset of pentylenetetrazol (PTZ)-induced seizures in ovariectomized rats. Materials and Methods: In this experimental study, sixty female Wistar rats were randomly divided into six groups of ten. All of the groups except for the negative control groups were ovariectomized. One group received estradiol (100 µg/kg), one group was treated with alcoholic extract of soy (20 mg/kg), and the other group received vehicle over 28 days. PTZ (90 mg/kg) was used to induce seizure in all groups. Behavioral changes were observed over 30 minutes. All data were analyzed using a two-way analysis of variance with Tukey’s post-hoc test. Results: The mean ± SD of the clonic seizure threshold was 61.84 ± 8.53 in the group that received estradiol, while it was 71.70 ± 10.85 in the control group, 64.69 ± 3.23 in rats with laparotomy without removing the ovaries, 51.30 ± 6.84 in rats with laparotomy and removing the ovaries, 52.7 ± 7.18 in ovariectomized rats that received sesame oil as vehicle, and 59.2 ± 4.91, in the soy groups. Therefore, estradiol significantly increased the clonic seizure threshold, while the alcoholic extract of soy had no effect. Conclusions: We concluded that the chronic administration of estradiol has an anticonvulsant effect in the animal model. However, alcoholic extract of soy has no effect on the onset of clonic seizures

Power-law Parameterized Quintessence Model

We introduce a power-law parameterized quintessence model for the dark energy which accelerate universe at the low redshifts while behaves as an ordinary matter for the early universe. We construct a unique scalar potential for this parameterized quintessence model. As the observational test, the Supernova Type Ia (SNIa) Gold sample data, size of baryonic acoustic peak from Sloan Digital Sky Survey (SDSS), the position of the acoustic peak from the CMB observations and structure formation from the 2dFGRS survey are used to constrain the parameters of the quintessence model. The best fit parameters indicates that the equation of state of this model at the present time is less than one $(w_0<-1)$ which violates the energy condition in General Relativity. Finally we compare the age of old objects with age of universe in this model.Comment: 11 pages, 17 figures, submitted to Phys. Rev.