Bioavailability of Potentially Toxic Elements in Foraged Fruits from a Former Industrial Site

Samples of foraged fruits from a former industrial site have been analyzed for potentially toxic elements (PTEs) (i.e., As, Cd, Cr, Cu, Ni, Pb, and Zn). The foraged fruit (blackberries, rosehips, and sloes) was gathered over two seasons along with samples of soil from the same sampling areas. All samples were acid digested, using a microwave oven, and then analyzed by inductively coupled plasma mass spectroscopy (ICP-MS). The concentration levels of the selected elements in foraged samples varied between not detectable limits and 24.6 μg/g (Zn). The soil-to-plant transfer factor was assessed for the PTEs. In all cases, the transfer values obtained were less than 1.00, indicating that the majority of the PTEs remains in the soil and that the uptake of PTEs from soil to plant at this site is not significant.     

Sedimentology of the Late Quaternary Wadi Hasa Marl Formation of Central Jordan: a record of climate variability

The sedimentary features and fossils within the Wadi Hasa Marl Formation coupled with optical luminescence chronology indicate alternating wet and dry periods have occurred on the Jordanian plateau since the last interglacial. The Jurf Ed Darawish Member rests unconformably on the Maastrichtian Muwaqqar Chalk Marl Formation and is composed predominantly of poorly sorted, clast-supported conglomerate. Palaeocurrents and clast composition indicate provenance from Cretaceous sedimentary rocks and Tertiary basalts to the west and southwest of the study site and the facies suggest a flashy alluvial depositional environment probably similar to the modern wadis. The overlying Burma Member consists of bedded grey-green clayey silts and marls with calcrete profiles, up to 1.2 m thick, and isolated gravel lenses. The fine-grained sediments contain charophytes, ostracods, bivalves and various species of gastropod indicating normal freshwater lacustrine conditions. The calcretes contain a poorly preserved fauna suggesting lacustrine deposition followed by subaerial exposure and pedogenesis. Three optical luminescence ages have been obtained from the Burma Member which suggest that the member ranges in age from >111 ka through to <40 ka. The facies variations are indicative of climatic fluctuations in Jordan during this period and human artefacts are found embedded in the sediments. This preliminary study suggests that the Late Quaternary central Jordan sedimentary record may preserve valuable evidence of complex climatic variation which will supplement the data from the Jordan Valley where tectonic activity complicates the sedimentary record.     

Prevalence of Dermatophytoses in the Zarqa District of Jordan

A total of 350 clinically suspected cases of dermatomycoses were examined for causative fungi during July 1997 to September 1998. Mycotic infection was demonstrable by microscopy and culture in 199 (56.8%) cases. The most common superficial mycotic infections were tinea pedis (35.2%) followed by tinea capitis (23.1%), tinea unguium (21.6%) and tinea corporis (10.6%). Most of the infected patients were 1–9, 20–29 and 30–39 years old. Men were mainly infected with tinea cruris and tinea pedis, while women were infected with tinea pedis, tinea unguium and tinea capitis. The frequencies of etiological agents isolated from patients were as follows: Trichophyton mentagrophytes var. interdigitale (32.7%), T. rubrum (28.6%), Epidermophyton floccosum (20.1%), Microsporum canis (11.1%), T.schoenleinii (4%), T.verrucosum (2%), T.violaceum (1%), and M. gypseum (0.5%). The number of infections varied with the seasons. The highest number of cases of tinea pedis and tinea cruris occurred in the summer months, while tinea capitis, tinea corporis and tinea unguium occurred in the spring and winter months. This revised version was published online in June 2006 with corrections to the Cover Date.     

Microfacies of Cambrian Limestones in Jordan

Summary The limestones of the Wadi Nasb Formation of the uppermost Lower Cambrian of Jordan are under- and overlain by massive sandstones of a near-shore facies. Facies analysis is based on samples from an outcrop at the northeastern shore of the Dead Sea and two oil test wells in the Wadi Sirhan Depression in eastern Jordan. Limestones were deposited in the shallow sea and within the coastal tidal area. Cyanobacteria, algae, echinoderms, trilobites and hyoliths have contributed the bulk of the carbonate and phosphatic material composing the Wadi Nasb limestone. Fine-grained facies types are composed of peloidal carbonate muds with laminar and nodular algal and cyanobacterial mats. They formed within a quiet tidallagoonal environment. The coarse grained facies types consist of carbonate sands with layers of sheell debris deposited in crossbeds in an environment with a rich endobenthic fauna. Here most particles were coated by cyanobacterial crusts. Ooids, oncoids and various coated grains are present. Consolidated sediments were commonly eroded within or near to this environment and their remains were integrated within the sands. Diagenesis is reconstructed step by step with deposition, first cementation, aragonite dissolution, compaction, pore filling, formation of pressure solution, growth of dolomite and anhydrite within the calcitic limestone and final fissure formation and filling.     

Phosphate sorption isotherms for evaluating phosphorus requirement of wetland rice soils

Summary Phosphate sorption isotherms were developed for five Philippine wetland rice soils using the conventional technique and a modified one. In the conventional method, P requirements of soils varied between 280 and 810 g P/g soil. In the modified method, they varied from 160 to 540 g P/g soil at 0.2 ppm P in solution. Soils with high P-sorption capacities had vermiculite and halloysite as the dominant clay minerals. Soil reduction by flooding decreased P-sorption by 28–70 percent at 0.2 ppm P in solution. The decrease in P-sorption due to soil reduction was greatest in a crystalline soil with vermiculite and halloysite as the dominant clay minerals and least in a soil with dominant X-ray amorphous silicates in the clay fraction.Desorption of freshly adsorbed P under reduction was greater in HCO₃^– solution than in CaCl₂ and it increased with level of applied P. Desorption patterns of freshly adsorbed P were similar to adsorption patterns but values of P in solution were lower at desorption. Soils varied with respect to desorption of freshly sorbed P. Desorption studies indicate that soils vary in intensity factor with respect to P and thus influence P availability to plants. Use of P-sorption and P-desorption data obtained under reduced soil condition was proposed for detecting P needs of submerged rice soils.Results of a pot study with IR36 at different levels of solution P (reduced) in one soil indicated a high degree of correlation between adjusted P levels and the measured growth parameters. About 0.12 ppm P in the soil solution or 0.46 ppm P desorbed in HCO₃^– solution (equivalent to 100 mg P/kg soil) was adequate for near-maximum plant height, tiller production, total dry matter yield, plant P content, and total P uptake.     

The distribution of phlebotomine sandflies in the principal ecological zones of Jordan

A survey of the sandflies (Diptera: Psychodidae) of Jordan increased the number of species known from the country from three to thirteen. Composition of the phlebotomine fauna and the relative abundance of sandfly species differ among the six climatic zones, with a general distinction between the dry desert zones and the more humid Mediterranean zones. Species of Phlebotomus predominate in the former and Sergentomyia in the latter. Within the desert zone some species are restricted to the eastern desert and others to the Jordan Valley in the west.     

Toxic dinoflagellates in the Mediterranean sea

Abstract

A review of the distribution of toxic dinoflagellates and related toxic events in the Mediterranean Sea is provided. Diarrhetic shellfish poisoning (DSP) and paralytic shellfish poisoning (PSP) are the main seafood contaminations, that have been reported since 1987. In 1994 four lethal cases for PSP were reported in Morocco. DSP seems to be restricted in the Northern part of the basin, while PSP contamination presents a wider distribution. Potentially DSP species, belonging to the genus Dinophysis, are widely distributed in the Mediterranean Sea, suggesting a wider extension of this contamination. The lack of monitoring programs in the Southern Mediterranean could be responsible of DSP overlooking. The species responsible for PSP are Gymnodinium catenatum in the Alboran Sea and Alexandrium minutum in various parts of the basin. Ichtyotoxic effects, due to Gymnodinium and Gyrodinium species, have been sporadically reported in some Mediterranean areas.     

Toxic ligand conjugates as tools in the study of receptor-ligand interactions

We have constructed hybrid proteins in which the toxic A chains of ricin or diptheria toxin have been linked to either asialofetuin, fetuin, or epidermal growth factor (EGF). Both ASF-RTA and ASF-DTA are potent toxins on cultured rat hepatocytes, cells that display the asialoglycoprotein receptor. Toxicity of these two compounds is restricted to hepatocytes and can be blocked by asialoglycoproteins but not the native glycoproteins or asialoagalactoglycoprotein derivatives, indicating that the toxicity of the conjugates is mediated by the hepatic asialoglycoprotein receptor. The EGF-RTA conjugate is an extremely potent toxin on cells that can bind the hormone, but is only poorly effective on cells that are unable to bind EGF. The EGF-DTA conjugate, in contrast, is unable to kill 3T3 cells and is at least two orders of magnitude less effective than EGF-RTA on A431 cells, a cell line with 1-2 X 10(6) EGF receptors per cell. However, when EGF-RTA and EGF-DTA were tested on primary liver hepatocyte cultures, which were susceptible to both ASF-RTA and ASF-DTA, both EGF conjugates were potent toxins. Sensitivity of the hepatocyte cultures to ricin toxicity increases slightly during a 52-hr culture period. In contrast, sensitivity to EGF-RTA and ASF-RTA decline dramatically during this period. Receptors for both ligands remain plentiful on the cell surface during this time.     

River Dan,headwater of the Jordan,an aquatic oasis of the Middle East

River Dan is the largest of the headwater rivers of the Jordan. The karstic exsurgence of the Dan has a seasonally stable output, a long stretch of strongly turbulent flow, stable temperature around 15.5°C and high oxygen saturation. A total of 156 taxa, mainly at the species level, were identified from the river. These species are almost exclusively of Palearctic origin. About half of the species are limited to the northernmost part of Israel. The faunal complex described, does not present any longitudinal zonation for the 5 kilometers of turbulent flow; neither does it present seasonal changes in species composition. River Dan is considered to be a post-Pleistocenic river which has an important function of refugium for a wide area of aquatic water-bodies in the area, including the presently drained Lake Hula. It is suggested that in the Illies scheme of stream classification, River Dan might represent a type of stream belonging to a ‘pseudorhithral’ along with other stenothermic warm water torrents of the tropical-subtropical climatic belt.     

Disease and mortality in the Early Bronze Age people of Bab edh-Dhra, Jordan.

During the 1977 field season at the Early Bronze Age site of Bab edh-Dhra 92 individuals were recovered from underground shaft tomb chambers. Morbid conditions found in these skeletons include trauma, possibly two cases of tuberculosis, osteomyelitis, post-menopausal osteoporosis and congenital anomalies. Of the 92 skeletons recovered 56 (61%) were 18 years of age or older, 28 (30%) were between 1 and 18 years of age and 8 (9%) were less than one year of age.     

A new marsilealean fern species from the Early Cretaceous of Jordan

Leaflets of Marsileaceae are described from the Albian (Early Cretaceous) strata of Jordan. The fossils are from the Jarash Formation (Kurnub Group) and are found in fluvial sediments along with water lily leaves. The small wedge-shaped leaves have dichotomous veins that anastomose and form a marginal vein. Based on comparisons to living genera, Marsileaceaephyllum mahisensis Hu, Taylor, Brenner et Basha, n. sp., is most similar to Marsilea, in particular, with terrestrial leaflet forms; yet, it is distinct from living and fossil species by its small size and the few dichotomously branched middle veins that have a monopodial course. In addition, a single similar-veined smaller leaf with a retuse apex is thought to be a juvenile leaf of the same species. This is the first megafossil evidence of the family from Africa/Arabian Peninsula.     

Polymicrobial infections in children with diarrhoea in a rural area of Jordan

Polymicrobial infections associated with diarrhoea are common in developing countries. Stool specimens were collected from 220 patient children and 100 controls. Potential pathogenic agents isolated from 143 (65%) children were identified by molecular and standard microbiological methods. Co-infections with two or more agents were detected in 50 (35%) cases. Escherichia coli, Shigella dysenteriae, Giardia and Entamoeba histolytica were found to be predominant. The etiologic agents could not be determined in 77 (35%) cases. The most significant risk factors were the age, the education level of the mother and the use of non-chlorinated water. The high infection rate of diarrhoeal diseases is a strong indication that these pathogens circulate easily through the population.     

Radiochemical neutron activation analysis in the life sciences

The contribution of radiochemical neutron activation analysis (RCNAA) to a better understanding of trace element analytics and physiology in the life sciences is outlined. Now, various non-nuclear powerful techniques for trace element analysis have become available, competing with RCNAA. This necessitates re-evaluation of the position of RCNAA, in particular versus inductively coupled plasmamass spectrometry (ICP-MS). On basis of the characteristic features of RCNAA and the capabilities of various competing non-nuclear analytical techniques, future niches for RCNAA in the analytical market are indicated. Presentation in memory of the late prof. Dr Jacques Versieck.     

Seroprevalence and Potential Risk Factors Associated with Neospora spp. Infection among Asymptomatic Horses in Jordan

This study aimed to determine the seroprevalence and to identify risk factors associated with Neospora spp. infection in horses in Jordan. Management related data were collected from each farm and individual horses. Sera from 227 horses from 5 of 6 climatic regions in Jordan were analyzed for the presence of antibodies to Neospora spp. by ELISA kit. The study was performed during spring of 2010. The association between seropositivity and risk factors was analyzed. A total of 7 (3%) of 227 sera had antibodies for Neospora spp. There was a significant regional difference (P=0.018) between the 5 climatic regions. Positive cases were located in Amman and Irbid, while the other regions (Zarqa, Jordan Valley, and Wadi Mousa) had zero prevalence. The use of anthelmintics at least once a year resulted in a significant reduction of the seroprevalence to Neospora spp. (1.6% vs 9.8%). However, this might be a phenomenon by chance and a better hygiene since owners can invest in anthelmintics. Other risk factors such as age, gender, breed, usage, body condition score, grazing, presence of other animals mixed with the horses in the same property, and a history of previous diseases were not significantly associated with the seroprevalence to Neospora spp. infection. This is the first study to report on the presence of Neospora seropositive horses in Jordan. Further studies are warranted to better understand the role of certain risk factors in the transmission of Neospora spp. among horse population and to determine which Neospora spp. are responsible for the infection.     

基因芯片技术在外源性化合物中毒机理研究中的应用

概述了外源性化合物的内分泌干扰中毒机理,并进一步探讨了基因芯片技术在中毒机理研究方面的应用.     

压力罐消解ICP-MS法同时测定全血中5种微量元素

为了建立同时测定全血中微量元素铬、锰、砷、镉、铅的电感耦合等离子体质谱(ICP-MS)分析法,采用压力罐消解技术对全血样品进行消化,使用ICP-MS法对全血中的五种微量元素铬、锰、砷、镉、铅含量进行测定。结果显示,全血样品中所测定的5种微量元素浓度为0~0.20μg·mL-1时,线性关系良好,相关系数r>0.999,各元素相对标准偏差(RSD)均小于5.0%(n=6),加标回收率为88.4%~107.6%,本法对铬、锰、砷、镉、铅的最低检出浓度分别为0.60、1.4、0.70、0.048、0.18μg·L-1。表明运用ICP-MS同时检测全血中微量元素具有良好的准确度和精密度、灵敏度高、检出限低、元素之间的干扰少,方法高效可行。     

Phosphate regulation of ACV synthetase and cephalosporin biosynthesis in Streptomyces clavuligerus

Cephalosporin production by Streptomyces clavuligerus was reduced sharply by 60 mM phosphate added to a chemically-defined medium. All the four synthetases in the pathway examined, i.e., ACV synthetase, cyclase, epimerase and expandase, were repressed by phosphate, with ACV synthetase being the main repression target and expandase the next. ACV synthetase activity was inhibited by phosphate to a lesser extent than expandase and cyclase, and this inhibition could be reversed by adding Fe2+. Fe2+ itself was inhibitory to ACV synthetase action.     

Toxic heavy metals and other trace elements in foodstuffs from 12 different countries

A research program related to the assessment of toxic heavy metals and essential trace elements in foodstuffs has been carried out in 12 countries under the auspices of the IAEA. The main purpose of this program was to obtain data on the elemental concentrations of potentially toxic elements in foodstuffs in various countries, and to compare them with the maximum permissible levels specified in national legislation and international guidelines. High-priority elements for this study were As, Cd, Cr, Pb, Hg, and Se. Also of interest, but of lower priority, were Sb Cu, and Zn/ Emphasis was placed on the use of nuclear and nuclear-related analytical techniques, complemented by conventional methods, and on quality assurance.