Moderate grazing is the best measure to achieve the optimal conservation and soil resource utilization (case study: Bozdaghin rangelands, North Khorasan, Iran).

The study of the variability of physical and chemical factors of soil due to different intensities of livestock grazing can help in the management and maintenance of soil and vegetation. Accordingly, the effect of livestock grazing intensities on soil properties and vegetation in Bozdaghin rangelands of North Khorasan province was investigated. To investigate the effect of different livestock grazing intensities, Three 5-hectare plots in the study area were determined under different treatments (ungrazed (UG), moderate grazing (MG), and heavy grazing (HG)), and the effect of three grazing intensities on vegetation and soil physicochemical and erodibility properties (SPEP) was evaluated. The soil sampling process was performed at depths of 0-15, 15-30 cm and SPEP including soil saturation moisture (SSM), soil texture (percentage of clay, sand, and silt), absorbable potassium (K), electrical conductivity (EC), soil organic matter (SOM), absorbable phosphorus (P), acidity (pH), and bulk density were evaluated, and Soil Erodibility Index (SEI) was calculated by implementing the modified clay ratio relation. To assess the impact of various grazing intensities on all measured characteristics, multivariate analysis of variance (MANOVA) and Duncan tests were utilized to compare the means and their grouping. The results showed that HG compared to MG causes worrying consequences in the first soil depth. Also with increasing grazing intensity, plant production percentage (P < 0.05) and vegetation density (P < 0.01) decreased, and the amount of bare soil (P < 0.01) increased. Also, with increasing grazing intensity, the amount of pH, EC, clay, saturated moisture, and N decreased (P < 0.01), but the amount of silt, sand, K, P, calcium (Ca), lime, and SOM increased (P < 0.01). UG improves soil quality, MG intensity causes optimal conservation and utilization of soil resources, and HG intensity causes severe changes in rangeland soil properties. In areas with MG intensity, due to the increase of the percentage of vegetation (an increase of SOM and prevents the direct impact of raindrops on the soil aggregates) and as a result improvement of soil structure and texture, an increase of water infiltration, and decrease of runoff, and the rate of soil erodibility and water erosion, the rangeland soil decreases and results in sustainable production. This results in optimal conservation and utilization of soil resources. So to sustainably exploit and balance the conservation of biodiversity, livestock production, and soil carbon and nitrogen management, MG is recommended.

Long-term grazing exclosure: implications on water erosion and soil physicochemical properties (case study: Bozdaghin rangelands, North Khorasan, Iran).

Grazing exclosure (GE) is used to improve rangelands in the dry area of the world, so it is important to investigate its effects on soil physicochemical and erodibility properties. This study was conducted to evaluate the effect of long-term GE on the physicochemical and erodibility properties of soil and vegetation as compared with open grazing (OG) areas in Bozdaghi region of North Khorasan province, Iran. Soil and vegetation data were sampled from two sites in the grazing exclosure and the open grazing in early autumn in a randomized complete block design with three replications. Therefore, in each area (GE and OG), three transects of 500-m length and 200-m intervals) were set up. Along each transect, five soil samples were taken at the depths of 0-15 and 15-30 cm in a random-systematic method (15 soil samples in each area) and transferred to the laboratory. In the laboratory, some soil physicochemical properties such as saturation percentage, soil texture (clay, silt, and sand), bulk density, porosity, percentage of soil organic matter (SOM), total nitrogen (TN), exchangeable sodium, potassium, pH, and electrical conductivity (EC) were measured and Soil Erodibility Index (SEI) was calculated by using the modified clay ratio relation. After installing the transects (with a length of 50 m) in three blocks in each area, the parameters of species composition and canopy cover were investigated by the linear-contact method. Data analysis was performed by using an independent t test on Statistical Package for Social Sciences (SPSS) v. 23 software. The results indicate that the application of GE in the Bozdaghi area has a significant positive effect on soil physicochemical properties (P < 0.05). Also, the application of GE has increased the amount of SOM and TN in the surface layer of the soil by about twice as much as the OG pastures. Due to these changes, during 20 years in the GE area, the effects of GE can be positively assessed. According to the obtained results, especially the positive changes in vegetation and the soil physicochemical and erodibility properties, it is recommended to execute the GE plan in the study area.

Stroke in the Blida region (Algeria) in 2018: Incidence and mortality according to a population-based register.

OBJECTIVE: Establishing the incidence and mortality data for stroke in the Blida region (Algeria) for 2018, through the setting up of a population-based register, was the objective of this study. METHODS: The World Health Organization criteria were used to define the stroke. Cerebral imaging was required to confirm stroke and its hemorrhagic or ischemic mechanism. The target population of the study was inhabitants of the region (wilaya) of Blida (Algeria) aged 25 and over. The ratios of overall incidence and mortality rates and age-specific stroke rates were considered to be relative risk (RR). The Standardized Mortality Ratio (SMR) was the ratio of standardized rates. RESULTS: A total of 828 stroke were reported, 85.1% ischemic and 13.5% hemorrhagic. The first-ever strokes constituted 70.5% of the strokes for which the occurrence was documented. The overall incidence rate of stroke for 2018, regardless of mechanism and occurrence, was estimated at 130.3/100000. The corresponding standardized rate for age was 138.1/100000. The incidence rate among men (143.6/100000) was significantly higher than that of women (116.9/100000): RR = 0.81 (95% CI: 0.71; 0.93). The median age of onset of stroke was 70 years. The case-fatality rate at 28 days was 22.1%. The overall mortality rate was 28.8/100000 while the corresponding standardized rate was 29.9/100000. The standardized mortality rate for men (34.5/100000) was significantly higher than for women (25.3/100000): SMR = 0.73 (95% CI: 0.54; 0.99). CONCLUSION: The setting up of a register for stroke in the Blida region has made it possible to quantify the risk of stroke, occurrence and death, and to alert about the burden of disease attributable to this health problem.

Effects of chitin and its derivatives on human cancer cells lines.

The present study is focused on the effect of chitin derivatives against human cancer cell lines RD and Hep2. As an outcome from this research, chitin was cytotoxic at IC50 = 400 µg/ml and 200 µg/ml against Hep2 cells and RD cells lines, respectively. Irradiated chitin had an IC50 value of 450 µg/ml for Hep2 and an IC50 of 200 µg/ml for RD. The lowest IC50 is attributed to chitosan, 300 µg/ml in Hep2 and 190 µg/ml in RD.

Comparison of two different doses of dexmedetomidine in attenuating cardiovascular responses during laryngoscopy and endotracheal intubation: A double blind, randomized, clinical trial study.

Introduction. Secure airway for proper ventilation during anesthesia is one important component of a successful surgery. Endotracheal intubation is one of the most important methods in this context. Intubation method and used medication are considerably important in attenuating complications. This research aimed to investigate the impact of two different doses of dexmedetomidine in mitigating cardiovascular responses to endotracheal intubation in candidate cases supporting voluntary operation. Methods. The current research contained 90 cases in the range of 18 and 50 old, with ASA I,II supporting voluntary operation, who were randomly classified into three teams, each group consisting of 30 cases. The first set (A) got 0.5 µg/ kg dexmedetomidine, the second set (B) got 1 µg/ kg dexmedetomidine and the third set (C) got an equal volume of saline as placebo, 600 seconds earlier the initiation of anesthesia. Hemodynamic parameters were recorded at baseline (T0), then after the injection and the earlier initiation of anesthesia (T1), after the induction of anesthesia and before the endotracheal intubation (T2), promptly after tracheal intubation, 180, and 300 after endotracheal intubation (T4, T5). Data was analyzed and p < 0.05 was supposed notable. Findings. In this research, 3 teams were similar regarding weight, age, height, sex and duration of laryngoscopy. The diastolic mean arterial pressure, heart rate, and systolic arterial pressure were significantly lower in dexmedetomidine teams (A,B) at all times after the endotracheal intubation compared to group C. There were no significant differences in hemodynamic factors among group A, B. Conclusion. Dexmedetomidine effectively and significantly attenuates cardiovascular and hemodynamic responses during endotracheal intubation. In addition, different doses of dexmedetomidine did not cause any significant distinct result in mitigating cardiovascular responses.

Anticancer activity of chemically prepared shrimp low molecular weight chitin evaluation with the human monocyte leukaemia cell line, THP-1.

In the present study, anticancer activities of chitin, chitosan and low molecular weight chitin were evaluated using a human tumour cell line, THP-1. A molecular weight-activity relationship and an electrostatic interaction-activity relationship were determined. The cytotoxic effects of chitin and derivatives were also evaluated using a normal human foetal lung fibroblastic cell line, MRC-5 and the specific cytotoxicity of chitin and derivatives to tumour cell lines was demonstrated. The high antitumour effect of low molecular weight of chitin was established.

Electrodialysis with bipolar membrane for regeneration of a spent activated carbon.

The main purpose of the present work was to develop a treatment method to regenerate granular adsorbent beds saturated with H(2)S by utilizing three electrodialysis compartments equipped with a cation or an anion exchange membrane or a bipolar membrane. Three electrodialysis compartments were utilized under various experimental parameters to determine the optimum conditions for the recovery of column particles saturated by H(2)S. The desulphurization operation is achieved with the extent of extraction close to 90% and an electric current density of about 30%. Use of the bipolar membrane makes it possible to regenerate the saturated adsorbent granules without adding chemical products. Since the only reagent was electricity, the projected economics are very attractive.

Enzymatic saccharification of solid residue of olive mill in a batch reactor.

This paper describes the enzymatic hydrolysis of solid residue of olive mill (OMRS) in a batch reactor with the Trichoderma reesei enzyme. Before enzymatic saccharification, crude lignocellulosic material is submitted to alkaline pre-treatment with NaOH. Optimum conditions of the pre-treatment (temperature of T=100 degrees C and OMRS-NaOH concentration ratio of about R=20) were determined. The optimum enzymatic conditions determined were as follows: pH of about 5, temperature of T=50 degrees C and enzyme to mass substrate mass ratio E/S=0.1g enzyme (g OMRS)(-1). The maximum saccharification yield obtained at optimum experimental conditions was about 50%. The experimental results agree with Lineweaver Burk's formula for low substrate concentrations. At substrate concentrations greater than 40gdm(-3), inhibitory effects were encountered. The kinetic constants obtained for the batch reactor were K(m)=0.1gdm(-3)min(-1) and V(m)=800gdm(-3).