Chronological response of prostacyclin changes to moderately low doses of radiation in rat cervical spinal cord

Background: Study of vascular and its secretory profile changes is an important issue in pathogenesis of radiation myelopathy. This paper reports the prostacyclin concentration changes after low-moderate doses of X-irradiation within a short period of time. Materials and Methods: Cervical cords of Wistar rats were irradiated to doses of 0.5, 1, 2, 4 and 6 Gy X-rays. After 24 hours, 2 and 13 weeks post-irradiation, prostacyclin contents were quantified and cords specimens were also stained routinely for histological studies. Results: Twenty four hours post-irradiation, showed a decrease in the content of prostacyclin after doses of 0.5 and 1 Gy 91.67±1.47 96.80±2.17 of respectively age-matched control group. After 2 weeks the concentration of prostacyclin showed significant decreases after 6 Gy. After 13 weeks irradiation shows marked differences even after a small dose of 2 Gy (p<0.001), and after doses of the low dose group. The differences between concentration values at doses of 4 Gy and 6 Gy were significant in comparison with the control (p<0.001 and p<0.002, respectively). Conclusion: Results suggested that the response of the vascular tissues to low and moderate doses of radiation occurs prior to that of the nervous tissue of the spinal cord. It means that the asymptomatic interval after radiation is characterized by sequential physiological changes which are imperfectly reflected in routine histological study and that even in the histologically unaffected spinal cord; severe impairment is present in substructures and biochemistry of irradiated spinal

Chewing activity, metabolic profile and performance of high- producing dairy cows fed conventional forages, wheat straw or rice straw

In this study, production and physiological responses of high-producing dairy cows fed wheat (WS) or rice (RS) straw, as a partial forage replacement for the conventional forages lucerne hay (LH) and maize silage (MS ), were investigated. The straws were treated under dry alkaline conditions, adjusted pH (pH ~12), and then ensiled. Twelve lactating Holstein cows were used in a replicated (n = 4) 3 × 3 Latin square design experiment with three periods of 21 days. Cows were offered one of three diets that differed in their forage sources: 1) 20% LH and 20% MS (control); 2) 12.8% LH, 12.8% MS; and 12.8% WS; and 3) 12.8% LH, 12.8% MS and 12.8% RS. Diet 1 had 60% concentrate, and diets 2 and 3 had 61.6% concentrate. Diets were iso-nitrogenous and iso-energetic. Supplemental buffer (NaHCO3) was omitted from the straw diets. However, straw diets contained greater sodium and dietary cation-anion difference (DCAD) compared with the control diet. Cows fed the WS had significantly greater apparent dry matter (DM) (69.7 versus 63.9%) and neutral detergent fibre (NDF) (55.4 versus 42.4%) digestibility than cows fed the control. Additionally, feeding either WS or RS significantly increased dry matter intake (DMI) (27.5 versus 25.6 kg/d ) and milk production (48.4 versus 45.6 kg/d) compared with control, but milk components were unaffected by treatments. Plasma minerals and metabolites concentrations and ruminal, urinary and faecal pH were similar across treatments. Feeding WS and RS resulted in lower time spent chewing per kg DMI compared with the control ( P = 0.01 ). Although there were no significant differences in performance between WS and RS, nutrient digestibility (DM, OM, and CP) was significantly higher while total chewing was lower for the WS diet than the RS diet. Partial inclusion of dry treated straw in lactating diets (12.8% DM basis) led to increases in sodium and DCAD levels and improved digestibility, DMI and milk yield without negative effects. Keywords: Cation and anion difference, cereal straw dietary sodium, lactating [email protected]

Effects of N-Acetylcysteine on auditory brainstem response threshold shift in rabbits exposed to noise and carbon monoxide

Problem statement: Noise Induced Hearing Loss (NIHL) is one of the most important occupational disease in worldwide. NIHL has been found to be potentiated by simultaneous Carbon monoxide (CO) exposure. Exposure to noise plus CO is common in occupational and environmental settings. Free radicals have been implicated in cochlear damage resulting from exposure to noise and due to CO hypoxia This study examined whether N-Acetylcysteine (NAC) administration cause attenuation of Auditory Brainstem Response (ABR) threshold shifts resulting from noise exposure and noise plus CO exposure. Approach: Forty-two rabbits were divided into seven groups including control, noise+ saline, noise+ CO +saline, noise+ NAC, noise+ CO+ NAC, CO+ NAC and NAC alone. ABR was assessed before exposure, 1 hour and 14 days post exposure. Results: The administration of 325 mg kg-1 of NAC prior, following and post exposure to noise or noise plus CO recovered permanent ABR threshold shift at 1 and 2 kHz almost to the baseline and provided significant attenuation in permanent ABR threshold shift at 4 and 8 kHz in subjects which were exposed to noise but it did not block the potentiating of threshold elevation by CO exposure (extra threshold loss by combined exposure) at 4 and 8 kHz. Conclusion: NAC provides protective effect against hearing loss resulting from noise exposure and simultaneous exposure to noise plus CO. © 2010 Science Publications

Hexagonal Smoothness-Increasing Accuracy-Conserving Filtering

Discontinuous Galerkin (DG) methods are a popular class of numerical techniques to solve partial differential equations due to their higher order of accuracy. However, the inter-element discontinuity of a DG solution hinders its utility in various applications, including visualization and feature extraction. This shortcoming can be alleviated by postprocessing of DG solutions to increase the inter-element smoothness. A class of postprocessing techniques proposed to increase the inter-element smoothness is SIAC filtering. In addition to increasing the inter-element continuity, SIAC filtering also raises the convergence rate from order k+1k+1 to order 2k+12k+1 . Since the introduction of SIAC filtering for univariate hyperbolic equations by Cockburn et al. (Math Comput 72(242):577–606, 2003), many generalizations of SIAC filtering have been proposed. Recently, the idea of dimensionality reduction through rotation has been the focus of studies in which a univariate SIAC kernel has been used to postprocess a two-dimensional DG solution (Docampo-Sánchez et al. in Multi-dimensional filtering: reducing the dimension through rotation, 2016. arXiv preprint arXiv:1610.02317). However, the scope of theoretical development of multidimensional SIAC filters has never gone beyond the usage of tensor product multidimensional B-splines or the reduction of the filter dimension. In this paper, we define a new SIAC filter called hexagonal SIAC (HSIAC) that uses a nonseparable class of two-dimensional spline functions called hex splines. In addition to relaxing the separability assumption, the proposed HSIAC filter provides more symmetry to its tensor-product counterpart. We prove that the superconvergence property holds for a specific class of structured triangular meshes using HSIAC filtering and provide numerical results to demonstrate and validate our theoretical results

A Case Study to Evaluate the Role of Basiluses in Producing Biosurfactant and the Feasibility of MEOR

Bibi Hakimeh oilfield consists of more than 145 oil producing wells. Its Oligomiocene Asmari reservoir is dominantly made of limestone. The act of a reverse fault on the north flank of Bibi-Hakimeh Field caused a significant thickness reduction in Gachsaran formation in the way that in some drilled wells, members No. 2, 3, 4, 5 and 6 of Gachsaran cap rock have been totally eliminated. This causes locating Asmari reservoir in a shallower level and therefore lowers reservoir temperature in the North flank already have made the reservoir suitable for a microbiological enhanced recovery. The long term production of this reservoir caused a significant reservoir pressure drop. Therefore; the recovery has been performed using Basilus with Ex-Situ method. In this case study, the feasibility of surfactant production in several oil wells has been accomplished. A high temperature resistant Basilus has been selected to evaluate the production ability of biosurfactant. This bacterium has been chosen after performing all morphological, biochemical and genetic studies. This bacteria shows a good resistance against the temperature in such manner that its emulsification, surface tension and inter surface tension abilities do not change after 15 min in an autoclave process at 120° C. In the next step, the temperature, pH, Carbon, N2 and other factors have been optimized for biosurfactant                                     production. Considering the lithology of the reservoir using this type of bacterium. This can be a good way to produce lipopithidic biosurfactant by Ex-Situ method in Asmari to enhance oil recovery. The basilus, which has good resistance against temperature and acts well in pressurized environments, can be considered as a good candidate for tertiary enhanced oil recovery process. The best method to produce basilus in B5 is the Formislink method

Lai-Massey Scheme Revisited

Lai-Massey scheme is a well-known block cipher structure which has been used in the design of the ciphers PES, IDEA, WIDEA, FOX and MESH. Recently, the lightweight block cipher FLY applied this structure in the construction of a lightweight $8 \times 8$ S-box from $4 \times 4$ ones. In the current paper, firstly we investigate the linear, differential and algebraic properties of the general form of S-boxes used in FLY, mathematically. Then, based on this study, a new cipher structure is proposed which we call generalized Lai-Massey scheme or GLM. We give upper bounds for the maximum average differential probability (MADP) and maximum average linear hull (MALH) of GLM and after examination of impossible differentials and zero-correlations of one round of this structure, we show that two rounds of GLM do not have any structural impossible differentials or zero-correlations. As a measure of structural security, we prove the pseudo-randomness of GLM by the H-coefficient method

Effects of hydrological events on morphological evolution of a fluvial system.

This study quantifies morphological evolution of the Dez River, Iran, from 1955 to 2016. The approach uses a sequence of Landsat images, aerial photos, and topographic maps. In addition, the hydrological data including average daily discharge and yearly maximum discharge at the Dezful hydrological station for the period (1955-2016) were used. The study reach was divided into 48 meander loops from upstream to downstream. Active channel width (w) was determined at 10 m intervals and changes assessed along the study reach of the Dez River. Morphological indices including sinuosity index; straight meander length; centerline flow length; erosion area; erodible length channel migration; centerline elongation; and radius of curvature were calculated in the reach. Results showed that the study reach of the Dez River changed dramatically in response to major floods, although the general trend is towards a narrowing of active channel width by 38% in the period 1955-2016. Results show that most of the meander loops in the study area extended and expanded. Between 1989 and 1995, all types of meander change were observed. There was a direct correlation between the frequency of hydrological events (flood days) bigger than 2-years return period and elongation of bends

A More Explicit Formula for Linear Probabilities of Modular Addition Modulo a Power of Two

Linear approximations of modular addition modulo a power of two was studied by Wallen in 2003. He presented an efficient algorithm for computing linear probabilities of modular addition. In 2013 Sculte-Geers investigated the problem from another viewpoint and derived a somewhat explicit for these probabilities. In this note we give a closed formula for linear probabilities of modular addition modulo a power of two, based on what Schlte-Geers presented: our closed formula gives a better insight on these probabilities and more information can be extracted from it

Characterization of MDS mappings

MDS codes and matrices are closely related to combinatorial objects like orthogonal arrays and multipermutations. Conventional MDS codes and matrices were defined on finite fields, but several generalizations of this concept has been done up to now. In this note, we give a criterion for verifying whether a map is MDS or not