Elemental analysis of some Egyptian ores and industrial iron samples by neutron activation analysis

ＩｎｔｒｏｄｕｃｔｉｏｎＮｏｗａｄａｙｓ,ｍｏｒｅｉｎｔｅｒｅｓｔｈａｓｇｒｏｗｎｉｎｔｈｅｄｅｔｅｒｍｉｎａｔｉｏｎｏｆｔｈｅｅｌｅｍｅｎｔａｌｃｏｎｓｔｉｔｕｅｎｔｓｏｆｍｏｓｔｉｎｄｕｓｔｒｉａｌｍａｔｅｒｉａｌｓｓｕｃｈａｓｉｒｏｎｗｈｅｒｅｓｅｖｅｒａｌｄｉｆｆｅｒｅｎｔｍｅｔｈｏｄｓａｒｅｕｓｅｄ(Ｈａｓｓａｎ ,1982 ;Ａｂｄｕｌ,1990 ;Ｆａｉｌｅｙ ,1979;Ａｎｄｅｒｓｏｎ ,1981) .Ｒｅｃｅｎｔｌｙ ,ｔｈｅｒｅｗｅｒｅｍａｎｙｉｎｖｅｓｔｉｇａｔｉｏｎｓｏｎｅｌｅｍｅｎｔａｌａｎａｌｙｓｉ…     

Long-term effects of lead poisoning on bone mineralization in vultures exposed to ammunition sources

Long-lived species are particularly susceptible to bioaccumulation of lead in bone tissues. In this paper we gain insights into the sublethal effects of lead contamination on Egyptian vultures (Neophron percnopterus). Our approach was done on the comparison of two populations (Canary Islands and Iberian Peninsula) differing in exposures to the ingestion of lead ammunition. Blood lead levels were higher in the island population (Canary Islands range: 5.10-1780 μg L⁻¹n = 137; Iberian Peninsula range: 5.60-217.30 μg L⁻¹n = 32) showing clear seasonal trends, peaking during the hunting season. Moreover, males were more susceptible to lead accumulation than females. Bone lead concentration increased with age, reflecting a bioaccumulation effect. The bone composition was significatively altered by this contaminant: the mineralization degree decreased as lead concentration levels increased. These results demonstrate the existence of long-term effects of lead poisoning, which may be of importance in the declines of threatened populations of long-lived species exposed to this contaminant.     

Large-scale effects of a small herbivore on salt-marsh vegetation succession—A comparative study on three Wadden Sea islands

Grazing by livestock is used as a management tool to prevent the dominance of a single tall-growing specises during succession on European salt marshes. The effects of natural small herbivores are often neglected by managers. Long-term exclosure experiments on the island of Schiermonnikoog show that hares retard vegetation succession at the early stages of salt-marsh development. In the present study we test whether we can scale-up these exclosure studies to a whole salt-marsh system. We compared 30 years of undisturbed vegetation succession at the Wadden Sea islands of Schiermonnikoog, Rottumerplaat (both The Netherlands) and Mellum (Germany). Salt-marsh development started at all sites in the early 1970s. Hares have been present only on Schiermonnikoog. At each site an area was selected covering a gradient from high to low salt marsh. Surface elevation and clay thickness were measured and a vegetation map was made on the three islands. The areas showed similar clay thickness at low surface elevation, indicating similar sedimentation ratesand hence nitrogen inputs. Rottumerplaat and Mellum showed a higher dominance of the late successional speciesAtriplex portulacoides in the low marsh andElymus athericus in the high marsh compared to Schiermonnikoog. Typical mid-successional, important food plant species for hares and geese had a higher abundance at Schiermonnikoog. Patterns of vegetation development in the absence of hares followed the observed patterns in the smallscale exclosure experiments at Schiermonnikoog. Without hare grazing, vegetation succession proceeds more rapidly and leads to the dominance of tall-growing species in earlier stages of succession. The present study shows that next to large herbivores, small herbivores potentially have largescale effects on salt-marsh vegetation succession during the early successional stages.     

Multi-decadal Changes in Tundra Environments and Ecosystems: The International Polar Year-Back to the Future Project (IPY-BTF)

Polar and alpine environments are changing rapidly due to increases in temperature, which are amplified in the Arctic, as well as changes in many local factors. The impacts on ecosystems and their function have potential consequences for local residents and the global community. Tundra areas are vast and diverse, and the knowledge of geographical variation in environmental and ecosystem change is limited to relatively few locations, or to remote sensing approaches that are limited mostly to the past few decades. The International Polar Year, IPY, provided a context, stimulus and timely opportunities for re-visiting old research sites and data sets to collate data on past changes, to pass knowledge from old to new generations of researchers and to document environmental characteristics of sites to facilitate detection and attribution of future changes. Consequently, the project “Retrospective and Prospective Vegetation Change in the Polar Regions: Back to the Future,” BTF, was proposed and endorsed as an IPY activity (project #512). With national funding support, teams of researchers re-visited former sites and data sets throughout the Arctic and some alpine regions. These efforts have amounted to a gamut of “BTF” studies that are collectively geographically expansive and disciplinary diverse. A selection of these studies are introduced and presented in the current issue together with a brief synthesis of their findings.     

Population dynamics and the physical and financial impacts to cereal crops of the Egyptian Goose Alopochen aegyptiacus on the Agulhas Plain, Western Cape, South Africa

Cereal crop farmers in the Western Cape province of South Africa regard the Egyptian Goose as a serious pest. The Agulhas Plain, in particular, attracts thousands of geese annually primarily because of the abundance and availability of nutritious crops such as wheat Triticum spp. and barley Hordeum spp. for food and permanent water bodies for roosting, moulting and breeding. Therefore, this paper investigates the population dynamics and physical and financial impacts to cereal crops of the Egyptian Goose on the Agulhas Plain, Western Cape. Egyptian Geese inflict damage during three main periods, viz. soon after sowing (surface seeds); young, developing plants (growing plants); and cut plants stacked in windrows (long, linear piles) to dry. The largest numbers of geese were recorded during June and July when they foraged on growing plants less than 25 cm tall. Overall, the mean yield loss was 65.6% in 1997 and 63.5% in 1998. Fields suffering greatest yield loss in 1997 and 1998 were generally those within 600 m of the roosting sites and had about 300 geese grazing on them on areas of around 2 ha in size for about 2 months. By August, geese moved from croplands on to pastures. During October and November, geese once again fed primarily on barley seeds in harvested crops stacked in windrows. Damage by geese to farmers was estimated to be >2.5 and 7% of annual revenue received from barley and wheat farming, in 1997 and 1998, respectively. There are many variables that need to be considered when attempting to quantify and explain damage to cereal crops by Egyptian Geese.     

Adsorption and thermodynamic parameters of chlorantraniliprole and dinotefuran on clay loam soil with difference in particle size and pH

The behavior of chlorantraniliprole (CAP) and dinotefuran (DNF) insecticides was investigated in clay loam soil, a common type of the Egyptian soil. Effect of temperature, pH and particle size of the soil on the adsorption process was studied. Adsorption isotherm by bulk soil and its constituents; humic acid (HA), clay, silt and sand fractions was measured using batch equilibration technique. The results showed that the adsorption of the insecticides tested was significantly affected by the temperature and was a spontaneous interfacial process in the soil. Freundlich model accurately predicted the adsorption behavior of both insecticides. The interaction between soil and insecticides was endothermic and the highest adsorption for CAP and DNF was obtained at pH 9. However, the effect of pH on the adsorption of DNF was lower than that of CAP. Sorption of CAP and DNF on HA fraction was significantly greater than on clay fraction and bulk soil. In addition, the adsorption was significantly increased with particle size decrease. It could be inferred that the adsorption of CAP and DNF on clay loam soil was physical in nature and greatly influenced by the soil components, pH and temperature.     

Occupational injuries and health problems in the Egyptian Mediterranean fisheries

Marine fishing is one of the most dangerous occupations. So far, no studies addressing occupational safety and health in the Egyptian fisheries have been conducted. The objective of this study is to explore and identify the types and causes of, as well as some factors associated with, occupational accidents and illnesses in the Egyptian marine fisheries. A sample of 686 fishermen in El-Maaddiya fishing port were interviewed for collecting relevant data. This paper presents the types of injuries mentioned by the interviewed fishermen and their potential causes in terms of accident type and involved agency/agency part. Also, major health problems and potential causes are presented. Furthermore, a logistic regression analysis was performed to study the significance of the association of some factors, such as age, experience, education and fishing gear with the occurrence of injuries and illnesses. The results of this study show that the Egyptian fishing industry involve many hazardous work conditions and practices that result in high morbidity and mortality rates, and high injury rates. The study recommends further research on suitable measures for the management of this problem.