108 research outputs found
Digital clubbing in tuberculosis – relationship to HIV infection, extent of disease and hypoalbuminemia
BACKGROUND: Digital clubbing is a sign of chest disease known since the time of Hippocrates. Its association with tuberculosis (TB) has not been well studied, particularly in Africa where TB is common. The prevalence of clubbing in patients with pulmonary TB and its association with Human Immunodeficiency Virus (HIV), severity of disease, and nutritional status was assessed. METHODS: A cross-sectional study was carried out among patients with smear-positive TB recruited consecutively from the medical and TB wards and outpatient clinics at a public hospital in Uganda. The presence of clubbing was assessed by clinical signs and measurement of the ratio of the distal and inter-phalangeal diameters (DPD/IPD) of both index fingers. Clubbing was defined as a ratio > 1.0. Chest radiograph, serum albumin and HIV testing were done. RESULTS: Two hundred patients (82% HIV-infected) participated; 34% had clubbing by clinical criteria whilst 30% had clubbing based on DPD/IPD ratio. Smear grade, extensive or cavitary disease, early versus late HIV disease, and hypoalbuminemia were not associated with clubbing. Clubbing was more common among patients with a lower Karnofsky performance scale score or with prior TB. CONCLUSION: Clubbing occurs in up to one-third of Ugandan patients with pulmonary TB. Clubbing was not associated with stage of HIV infection, extensive disease or hypoalbuminemia
Biochar composition-dependent impacts on soil nutrient release, carbon mineralization, and potential environmental risk: A review
Biochar application has multiple benefits for soil fertility improvement and climate change mitigation. Biochar can act as a source of nutrients and sequester carbon (C) in the soil. The nutrient release capacity of biochar once applied to the soil varies with the composition of the biochar, which is a function of the feedstock type and pyrolysis condition used for biochar production. Biochar has a crucial influence on soil C mineralization, including its positive or negative priming of microorganisms involved in soil C cycling. However, in various cases, biochar application to the soil may cause negative effects in the soil and the wider environment. For instance, biochar may suppress soil nutrient availability and crop productivity due to the reduction in plant nutrient uptake or reduction in soil C mineralization. Biochar application may also negatively affect environmental quality and human health because of harmful compounds such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated dibenzodioxins, and dibenzofurans (PCDD/DF). In this review, we discuss the linkage between biochar composition and function, evaluate the role biochar plays in soil fertility improvement and C sequestration, and discuss regulations and concerns regarding biochar's negative environmental impact. We also summarize advancements in biochar production technologies and discuss future challenges and priorities in biochar research
Heavy Metals Accumulation by Ochradenus baccatus Plant Grown on Mining Area at Mahad AD'Dahab, Saudi Arabia
Plant species Ochradenus baccatus, which grown around Mahad AD’Dahab Mine, have been selected from 100m2 to study its ability to accumulate heavy metals (As, Cd, Cu, Pb, Zn). Five samples from shoots of Ochradenus baccatus were collected. Moreover, five soil samples were collected to make a representative soil sample. Plant and soil samples were analyzed for As, Cd, Cu, Pb, and Zn. Results showed high concentration of soil heavy metals content respect to As, Cd, Cu, Pb, and Zn (30, 7, 479, 355, 1481 mg kg-1 respectively). The concentration of Cd, Cu, Pb, Zn in shoots of Ochradenus baccatus were 1.7, 30.8, 10.2, 169.5 mg kg-1 respectively. On other hand, the concentration of heavy metals in the roots was as follows (mg kg-1): Cd: 3.9; Cu: 114; Pb: 43; Zn: 430. Except As, heavy metals (Cd, Cu, Pb, Zn) tend to be accumulated in the roots comparing with shoots. The accumulation coefficient of heavy metals in shoots was low (0.03-0.25), while it was higher in roots (0.04-0.58). Based on the accumulation coefficient, heavy metals can be ordered as follows: Cd> Zn> As> Cu> Pb for shoots and Cd> Zn> Cu> Pb> As for roots. ANOVA analysis was performed to examine the accumulation heavy metals by Ochradenus baccatus at 0.01 level. Significant difference was found between cd and other metals in both shoots and roots; while between Zn and other metals except As and Cu in shoots and roots respectively. From above, Ochradenus baccatus should be described as not-excluder and can be explored further for phytoremediation of metal polluted soils. On other hand, the practice of providing foliage and pods as fodder for live stock should be avoided in Mahad AD’Dahab are
Duodenal Ulcer and Helicobacter pylori Infection at High Altitude: Experience from Southern Saudi Arabia
OBJECTIVE: To study the clinical presentation, endoscopic features and prevalence of Helicobacter pylori in duodenal ulcer (DU) patients in southern Saudi Arabia, located 3150 m above sea level, and to compare results with those from low altitude regions of the Kingdom
Vegetation cover change detection and assessment in arid environment using multi-temporal remote sensing images and ecosystem management approach
Vegetation cover (VC) change detection is essential for a better
understanding of the interactions and interrelationships between humans and
their ecosystem. Remote sensing (RS) technology is one of the most beneficial
tools to study spatial and temporal changes of VC. A case study has been
conducted in the agro-ecosystem (AE) of Al-Kharj, in the center of Saudi
Arabia. Characteristics and dynamics of total VC changes during a period of
26 years (1987–2013) were investigated. A multi-temporal set of images was
processed using Landsat images from Landsat4 TM 1987, Landsat7 ETM+2000, and
Landsat8 to investigate the drivers responsible for the total VC pattern and
changes, which are linked to both natural and social processes. The analyses
of the three satellite images concluded that the surface area of the total VC
increased by 107.4 % between 1987 and 2000 and decreased by
27.5 % between years 2000 and 2013. The field study, review of secondary
data, and community problem diagnosis using the participatory rural appraisal
(PRA) method suggested that the drivers for this change are the deterioration
and salinization of both soil and water resources. Ground truth data
indicated that the deteriorated soils in the eastern part of the Al-Kharj AE
are frequently subjected to sand dune encroachment, while the southwestern
part is frequently subjected to soil and groundwater salinization. The
groundwater in the western part of the ecosystem is highly saline, with a
salinity  ≥ 6 dS m<sup>−1</sup>. The ecosystem management approach applied in
this study can be used to alike AE worldwide
Fertigation as a Tool to Improve Nitrogen Use Efficiency and Yeild
A greenhouse experiment was carried out at Almuzahemiah Research Station, King Abdulaziz City for Science and Technology (KACST), Riyadh, Saudi Arabia to evaluate the effect of fertigation on cucumber yield. There were five treatments, NO = control, soil Ns = 120 mg N L-1 and three treatments labeled N 15 (N1 = 60, N2 = 120 and N3 = 180 mgN15 L-1) to study there effects on cucumber (cultivar Figaro F-1) yield during 1996. The highest yield was 33.74 t ha-1 from N3 and the lowest 7.73 t ha-1 from the control treatment, Nitrogen use efficiency (NUE) varied between 72.7 – 129.53 kg kg-1 in the different N treatment. The mean N15 a.e. ranged from 0.01 – 0.884% (leaves), 0.058 – 0.855 % (shoots), and 0.07 – 0.823 % (fruits). In conclusion, nitrogen application through fertigation was more effective than the conventional method (soil application) for improving the greenhouse crop yields
The Changing Pattern of Upper Gastro-Intestinal Lesions in Southern Saudi Arabia: An Endoscopic Study
Biochar influences growth performance and heavy metal accumulation in spinach under wastewater irrigation
Effect of Pyrolysis Temperature on Biochar Microstructural Evolution, Physicochemical Characteristics, and Its Influence on Biochar/Polypropylene Composites
Environmental management through effective utilization of biowastes has been a topic of intensive research in recent years. This study examines the effect of pyrolysis temperature on the physical and morphological characteristic of biochar (BC) derived from lignocellulosic wastes. The biochar was prepared by pyrolysing date palm biomass at various temperatures, i.e., 300, 400, 500, 600, and 700 °C. These pyrolysed biochars were then characterized for their carbon content, mineral compositions, chemical functionalities, and morphological structures, for understanding their physicochemical characteristics and microstructural evolution. It was revealed that the pyrolytic condition plays a key role in the formation of biochar microstructure. These biochar samples were then utilized without any further treatments/purifications for their practical application as reinforcement materials for polymer composites. They were blended with a polypropylene matrix by a melt mixing technique followed by injection molding process. The type of biochar was found to significantly affect the composites properties. Differences in microstructure, surface chemistry, and chemical compositions of BCs were observed to be determining factors affecting the compatibility and thermomechanical properties of resulted composites
Potential short-term negative versus positive effects of olive mill-derived biochar on nutrient availability in a calcareous loamy sand soil.
In the present work, the olive mill solid waste (OMSW)-derived biochar (BC) was produced at various pyrolytic temperatures (300-700°C) and characterized to investigate its potential negative versus positive application effects on pH, electrical conductivity (EC), and nutrients (P, K, Na, Ca, Mg, Fe, Mn, Zn, and Cu) availability in a calcareous loamy sand soil. Therefore, a greenhouse pot experiment with maize (Zea mays L.) was conducted using treatments consisting of a control (CK), inorganic fertilizer of NPK (INF), and 1% and 3% (w/w) of OMSW-derived BCs. The results showed that BC yield, volatile matter, functional groups, and zeta potential decreased with pyrolytic temperature, whereas BC pH, EC, and its contents of ash and fixed carbon increased with pyrolytic temperature. The changes in the BC properties with increasing pyrolytic temperatures reflected on soil pH, EC and the performance of soil nutrients availability. The BC application, especially with increasing pyrolytic temperature and/or application rate, significantly increased soil pH, EC, NH4OAc-extractable K, Na, Ca, and Mg, and ammonium bicarbonate-diethylenetriaminepentaacetic acid (AB-DTPA)-extractable Fe and Zn, while AB-DTPA-extractable Mn decreased. The application of 1% and 3% BC, respectively, increased the NH4OAc-extractable K by 2.5 and 5.2-fold for BC300, by 3.2 and 8.0-fold for BC500, and by 3.3 and 8.9-fold for BC700 compared with that of untreated soil. The results also showed significant increase in shoot content of K, Na, and Zn, while there was significant decrease in shoot content of P, Ca, Mg, and Mn. Furthermore, no significant effects were observed for maize growth as a result of BC addition. In conclusion, OMSW-derived BC can potentially have positive effects on the enhancement of soil K availability and its plant content but it reduced shoot nutrients, especially for P, Ca, Mg, and Mn; therefore, application of OMSW-derived BC to calcareous soil might be restricted
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