Assessment of soil contamination caused by underground fuel leakage from selected gas stations in Riyadh,Saudi Arabia

ABSTRACT

Spills and leakage from underground fuel storage tanks (UFSTs) can potentially contaminate soil and groundwater and pose harmful effects to public health and the environment. This study evaluated the feasibility of using volatile organic compounds (VOCs), total petroleum hydrocarbons (TPHs), electrical conductivity (EC), and pH to examine the contamination caused by leaking UFSTs. Screening water assessments for VOCs and general water quality parameters were conducted on the premises of 53 gas stations in Riyadh, Saudi Arabia, to identify potentially contaminated sites, and 25 ground bores were drilled for the quantification of TPH concentrations, EC, and pH values in 407 soil samples. The experimental approach followed in this study included geochemical analyses based on borehole drilling at five targeted gas stations, analyses of water samples from underground storage reservoirs, and analyses of soil core samples obtained from different depths to determine the degree of TPH contamination. Thirty-five VOCs were identified in the water samples collected from gas stations. Methylene chloride, tribromomethane, toluene, chlorobenzene, dibromochloromethane, and benzene were frequently encountered in most of the water samples. Some of these samples exceeded the World Health Organization and Saudi Arabian guidelines for acceptable levels of pH, total dissolved solids, chloride, nitrate, sulfate, calcium, and total hardness. The measured TPH levels were clearly indicative of subsoil contamination and subsequent accumulation in soil over time, particularly at depths of 1–6 m; there was not a noticeable dependence or impact on pH.     

马来酸噻吗洛尔眼液联合拉坦前列素眼液对原发性开角型青光眼患者眼压的影响

目的:探讨马来酸噻吗洛尔眼液联合拉坦前列素眼液对原发性开角型青光眼患者眼压的影响。方法:选取2015年1月-2016年5月在我院接受治疗的原发性开角型青光眼患者84例,其中给予马来酸噻吗洛尔眼液治疗的42例记为对照组,给予拉坦前列素眼液联合马来酸噻吗洛尔眼液治疗的42例记为观察组,两组均治疗6个月。对比两组患者治疗过程中的眼压变化情况,并对比两组患者的临床总有效率、药物依从性和并发症情况。结果:观察组治疗2、4、6个月后的眼压均显著低于对照组(P0.05),观察组患者治疗6个月后与治疗前的眼压差值大于对照组(P0.05)。两组患者治疗2、4、6个月后的眼压呈下降趋势,两两比较差异均有统计学意义(P0.05)。观察组的临床总有效率95.24%显著高于对照组的80.95%(P0.05)。两组患者在治疗过程中结膜充血、眼内异物感、眼睛疼痛、视力模糊、味觉异常以及总并发症发生率对比差异不显著(P0.05)。观察组患者的药物依从性比例显著低于对照组(P0.05)。结论:马来酸噻吗洛尔眼液联合拉坦前列素眼液治疗原发性开角型青光眼患者具有较好的临床疗效,可显著降低患者眼压,同时具有较好的安全性,但药物依从性较差。     

Sucrose-phosphate synthase activity and yield analysis of tomato plants transformed with maize sucrose-phosphate synthase

Sucrose synthesis is a major element of the interactions between photosynthesis and plant growth and development. Tomato (Lycopersicon esculentum Mill. cv. UC82B) plants transformed with maize sucrose-phosphate synthase (SPS; EC 2.3.1.14) expressed from either a ribulose-1,5-bisphosphate carboxylase-oxygenase (Rubisco) small subunit promoter (SSU) or the cauliflower mosaic virus 35S promoter (35S) were used to study effects of increased sucrose synthesis rates on plant growth. The plants were grown in growth chambers, field plots, and open-top chambers. The 35S plants had a 2 to 3-fold increase in young-leaf SPS activity, a 10 to 20-fold increase in young-root SPS activity and no increase in young-fruit SPS activity. The leaf SPS activity in one of the 35S lines fell to control levels by two months of age. The SSU plants had a 4 to 5-fold increase in leaf SPS activity and no significant increase in root or young-fruit SPS activity. One 35S line, which maintained high leaf SPS activity throughout development, yielded 70–80% more than controls at both normal and elevated CO₂ in open-top chambers in the field and 20–30% more than controls in two additional field trials. The other 35S line and the two SSU lines either yielded less or did not differ from controls under several growth conditions. Since only one of four transformed lines showed an increase in yield, we can not yet conclude that increased leaf SPS activity leads to increased yield. However, increased leaf SPS activity appears to result in increased fruit sugar content since all three lines with increased leaf SPS usually also had increased fruit sugars. Received: 18 November 1996 / Accepted: 22 January 1997     

Comparative studies on the diagnosis of hepatitis E virus antibodies with ORF-2 and ORF-3 proteins expressed in insect cells

Hepatitis E is a worldwide health problem, especially in developing countries. The virus genome contains three different open reading frames (ORFs): ORF-1, which is believed to encode nonstructural proteins, and ORF-2 and ORF-3, which are believed to encode structural proteins. Presently, serologic tests for the detection of human antibodies to hepatitis E virus (HEV) infection are primarily based on the ORF-2 structural protein expressed inEscherichia coli, insect cells or synthetic peptides. We report here the comparative studies on the diagnosis of HEV infection with full-length ORF-2 and ORF-3 proteins expressed in insect cells. We found that 31 of 74 (42%) sera were positive for IgM antibody to HEV (anti-HEV) using the ORF-2 protein as an antigen, as compared to 6 of 74 sera (8%) using the ORF-3 protein as an antigen (p<0.001). Similarly, 49 of 74 sera (66%) were positive for IgG anti-HEV utilizing the ORF-2 protein versus 12 of 74 sera (16%) when the ORF-3 protein was used (p<0.001). These results suggest that the recombinant ORF-2 protein is more sensitive as a diagnostic antigen for detecting antibodies to HEV in both acute-phase and convalescent-phase sera than ORF-3 protein.     

A new digital field data collection system for dendrochronology

A wide variety of information or ‘metadata’ is required when undertaking dendrochronological sampling. Traditionally, researchers record observations and measurements on field notebooks and/or paper recording forms, and use digital cameras and hand-held GPS devices to capture images and record locations. In the lab, field notes are often manually entered into spreadsheets or personal databases, which are then sometimes linked to images and GPS waypoints. This process is both time consuming and prone to human and instrument error. Specialised hardware technology exists to marry these data sources, but costs can be prohibitive for small scale operations (>$2000 USD). Such systems often include proprietary software that is tailored to very specific needs and might require a high level of expertise to use. We report on the successful testing and deployment of a dendrochronological field data collection system utilising affordable off-the-shelf devices ($100–300 USD). The method builds upon established open source software that has been widely used in developing countries for public health projects as well as to assist in disaster recovery operations. It includes customisable forms for digital data entry in the field, and a marrying of accurate GPS location with geotagged photographs (with possible extensions to other measuring devices via Bluetooth) into structured data fields that are easy to learn and operate. Digital data collection is less prone to human error and efficiently captures a range of important metadata. In our experience, the hardware proved field worthy in terms of size, ruggedness, and dependability (e.g., battery life). The system integrates directly with the Tellervo software to both create forms and populate the database, providing end users with the ability to tailor the solution to their particular field data collection needs.     

Effects of deer browsing on the early stage of pyrogenic succession on Miyajima Island,southwestern Japan

The early stage of forest regeneration on Miyajima Island, southewstern Japan, was studied for three years after a fire in 1984, with respect to the effects of deer browsing. The regeneration patterns of woody species, in terms of the biomass increment and browsing damage to plants, were classified into the following three groups: non- or rarely browsed species with little increment of biomass, heavily browsed with little increment, and heavily browsed with large increment. The aboveground biomass increased from 0.4 kg to 2.7 kg per 100 m² during three years, and was less than half of the biomass obtained in other burnt pine forests on the adjacent deer-free islands. About 28% of the plant biomass was consumed by deer. The effects of browsing on forest regeneration were heavier at lower than that at the higher altitudes. On this island, deer browsing seems to have an important effect on vegetational succession in the burnt areas.     

Effects of mineral turbidity on freshwater plankton communities: Three exploratory tank experiments of factorial design

We conducted three exploratory experiments of factorial design on the effects of mineral turbidity in 18 large (7 000 1) fiberglass tanks containing plankton communities derived from Lake Texoma (Oklahoma-Texas), a large reservoir often subject to turbid inflows. Replicate plankton communities developed for 30–45 d in response to 4–9 treatments of planktivorous fish, dead fish, nutrient additions and artificial removal of zooplankton with plankton netting (or combinations of these manipulations). In one experiment we then added three concentrations of kaolin and in the other two experiments we added bentonite or powdered silica to the replicate tank communities. We measured the responses of the diverse plankton communities to the addition of mineral turbidity for an additional period of 30–45 d.Effects of introduced minerals (quality or concentration effects) and food web treatments after mineral addition (fish, nutrients, etc.) were determined by analysis of covariance after observations were adjusted for the value of each response variable at the time of mineral addition. Covariance analysis resulted in a statistical model explaining > 80% of the variance for most response variables. The values of response variables at the time of mineral addition were often the most important source of variation, suggesting the importance of biotic community resiliency to the effects of mineral turbidity. There were few effects of mineral particles on physical or chemical (temperature, conductivity, oxygen, pH), nutrient (nitrate, phosphate, alkalinity) or biotic (algal or zooplankton populations) components of the tank communities. Mineral effects were found for several measures of water clarity (Secchi depth, turbidity, and the concentration of small sestonic particles).     

腔镜下Soave根治术与开腹改良Soave术治疗长段型先天性巨结肠患儿的疗效比较及对应激反应和控便功能的影响

摘要 目的：比较腔镜下Soave根治术与开腹改良Soave术治疗长段型先天性巨结肠（HD）患儿的疗效,观察两种术式对应激反应和控便功能的影响。方法：选取我院2017年4月～2020年9月期间收治的长段型HD患儿88例,根据手术方式的不同分为开腹组和微创组,例数分别为43例和45例。对比两组围术期指标、应激反应指标、控便功能和并发症发生情况。结果：微创组的术中失血量少于开腹组,手术时间、胃肠功能恢复时间、禁食时间、住院时间短于开腹组（P<0.05）,两组肠管切除长度组间对比无统计学差异（P>0.05）。两组患儿术后1 d心率（HR）、平均动脉压（MAP）较术前升高,血氧饱和度（SpO₂）较术前下降,但微创组HR、MAP低于开腹组,SpO₂高于开腹组（P<0.05）。两组患儿术后1年大便性状、排便次数、污粪、需要治疗（灌肠、药物、尿布）评分及Heikkinen总分均较术前升高,且微创组高于开腹组（P<0.05）。微创组的近期并发症总发生率和远期并发症总发生率均低于开腹组（P<0.05）。结论：与开腹改良Soave术相比,采用腔镜下Soave根治术治疗长段型HD患儿可缩短手术时间、禁食时间、住院时间、胃肠功能恢复时间,减少手术创伤,减轻机体应激反应,改善患儿控便功能,同时还可降低并发症发生率,效果较好。     

Glaucoma Pred: Glaucoma prediction based on Myocilin genotype and phenotype information

Glaucoma is the second leading cause of blindness after cataract and is heterogeneous in nature. Employing a genetic approach for the detection of the diseased condition provides an advantage that the gene responsible for the disease can be identified by genetic test. The availability of predictive tests based on the published literature would provide a mechanism for early detection and treatment. The genotype and phenotype information could be a valuable source for predicting the risk of the disease. To this end, a web server has been developed, based on the genotype and phenotype of myocilin mutation, which were identified by familial linkage analysis and case studies. The proposed web server provides clinical data and severity index for a given mutation. The server has several useful options to help clinicians and researchers to identify individuals at a risk of developing the disease. Glaucoma Pred server is available at http://bioserver1.physics.iisc.ac.in/myocilin.