Effects of Polyacrylamide on Rangeland Soils and Plants

The objectives of this study were to determine the effects of two forms of polyacrylamide (PAM) conditioners (Cross-linked and Non-cross-linked PAM) on evaporation, saturated hydraulic conductivity, water retention, crust and crack formation of soils, seed germination, and seedling and tubeling growth. The two PAM conditioners, 0.2% concentration by weight, were mixed with seven soils of different textures (sandy loam, silt, silty clay loam, silt loam, fine sand, medium sand, and coarse sand) to investigate the effects on evaporation, saturated hydraulic conductivity, and water retention. Soil samples of different textures were brought to field capacity and placed in a growth chamber for two weeks to measure evaporation under a controlled environment. A second experiment was carried out in the field to determine the effects of the two PAM conditioners on seedling emergence of crested wheatgrass, Agropyron desertorum, as well as on soil cracking, penetrometer resistance, and soil moisture. The two PAMs were mixed with a silt loam Xerollic Calciorthid at 0.2% concentration by weight. Seedling emergence was monitored directly for two weeks. Soil moisture was measured by TDR. Cracking was described by photographic means. Penetrometer resistance was measured by a hand-held. penetrometer. The third experiment was also carried out in the field, using the same soil texture as in experiment 2, to investigate the effects of the two PAMs on soil moisture at depths between 25 to 45 cm and on sagebrush (Artemisia tridentata) growth. Evaporation was found to be significantly lower in the fine-textured controls than under the two PAM treatments. The sandy loam and sandy soils experienced significantly higher evaporation from the controls. The two PAM conditioners significantly reduced saturated hydraulic conductivity on all soil textures. Water retention increased in the PAM-treated textures at the matric potential range used (0.0, 0.05, 0.1, 1.5 MPa) • The PAM application also did not improve grass seedling emergence or improve soil moisture, and did not have any significant affects on sagebrush growth. Larger cracks were found in the two plots treated with PAM than the controls. Lower penetrometer resistance occurred in the two PAM treatments compared to the untreated control. From this study, it can be concluded that the application of PAM conditioners, at relatively high concentrations used, could be more viable on sandy textures. Other researchers are advised to try lower application rates than used here, particularly with finer textured soils

PEPTIDE BASED TARGETED RADIONUCLIDE THERAPIES; SCIENCE BEHIND THE SUCCESS.

The radionuclide therapies for solid and liquid malignancies are emerging field nowadays. The targeted radionuclide therapies have been in use since 1945. In the past 20 years, due to advancement in the nanotechnology and targeting cell receptors; radionuclide therapies have emerged as a subspecialty in nuclear medicine. Through this article, we would like to briefly describe the evolution of peptide-based radionuclide therapies, with a little emphasis on their clinical applications. Key words: Peptide-based radiopharmaceuticals, radionuclide therapy, somatostatin-receptor-positive neuroendocrine tumou

Multicenter Study of Brucellosis in Egypt

Brucellosis causes appreciable economic losses in livestock. Examination of milk and tissues from animals in Egypt for Brucella spp. showed increased prevalence rates of serologically reactive animals. All isolates were B. melitensis biovar 3. One Brucella sp. was isolated from milk of serologically nonreactive buffaloes

Gulf Cooperation Council Countries’ Stock Market Response to US Federal Reserve Policy Actions

This study examines the effects of changes in the United States’ (US) monetary policy actions on the Gulf Cooperation Council (GCC) countries’ stock markets. Efficient financial markets are unlikely to respond to anticipated policy actions. Therefore, Federal funds futures data are used to categorize the changes in monetary policy actions into anticipated and unanticipated components. The results indicate that equity returns across the GCC are roughly 19 percentage points more volatile on monetary policy event days than non-event days. We find that a surprise change in the Federal funds rate is positive on equity prices and statistically significant across all GCC countries except for Bahrain, where it is negative and statistically significant. On average, a hypothetical unanticipated 25-basis-point hike in the Federal funds rate target is associated with a 1.5% increase in the GCC broad stock indexes. These findings are relevant to both the direction and context of Federal funds rate surprises

Native Perennial Plants Colonizing Abandoned Arable Fields in a Desert Area: Population Structure and Community Assembly

In recent years, the phenomenon of abandonment of arable fields has increased in Saudi Arabia due to low soil fertility, drought, low rainfall, high levels of evapotranspiration, soil salinization, and low level of groundwater. We evaluated the effect of agricultural land abandonment on soil properties, perennial vegetation composition, and population structure in the Al-Kharj region, Saudi Arabia. A total of 11 perennial plant species belonging to 9 families and 11 genera were detected in the different abandoned fields of the study area. Four plant communities were identified after the application of the detrended correspondence analysis (DCA) ordination. The indicator species were (1) Seidlitzia rosmarinus—Zygophyllum hamiense, (2) Traganum nudatum—Seidlitzia rosmarinus, (3) Traganum nudatum—Prosopis farcta, and (4) Calligonum comosum—Pulicaria undulata. Results of the soil analysis showed significant differences in soil texture, pH, salinity, and nutrient content among the four recognized plant communities. Demographic analysis indicated that populations of Zygophyllum hamiense and Calligonum comosum tended to be either inverse J-shaped or positively skewed which may have indicated rapidly-growing populations with high reproductive capacity. Conversely, the size–frequency distribution of Traganum nudatum, S. Rosmarinus, and Prosopis farcta was approximately symmetrical (i.e., bell-shaped). The present study sheds light on the necessity of managing abandoned agricultural fields for restoring and improving rangelands with native species that are adapted to the local conditions such as low water demand