The history and fate of the Nubian Sandstone Aquifer springs in the oasis depressions of the Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Powell, Owen; Fensham, Rod

2016-03-01

Extraction of groundwater for agriculture has resulted in the loss of springs across arid regions of the globe. The history and fate are recorded of the artesian springs of Egypt's Western Desert, from ancient times to the present, spanning the rise and fall of the great civilisations from the Pharoanic dynasties to Persian, Greek and Roman conquests. The study area includes oases Kharga, Dakhla, Bahriya, Farafra and Siwa, and several outer and small oases around Siwa and the edge of the Qattara Depression. The region is hyper-arid, receiving 10 mm or less average annual precipitation and evaporation rates are in the vicinity of 3,000 mm/a. Groundwater in the oases is largely derived from bores discharging from the Nubian Sandstone Aquifer. Based on an extensive survey, conducted for the first time, attention is drawn to the rapid demise of springs as a result of modern irrigation schemes which continue to deplete groundwater supplies.

The geochemistry of uranium and thorium isotopes in the Western Desert of Egypt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dabous, A.A.

1994-11-01

The concentrations of {sup 238}U, {sup 234}U, {sup 232}Th, and {sup 228}Th have been measured in the groundwaters of the Bahariya and Farafra oases of the Western Desert of Egypt. These waters are characterized by normal amounts of U, but unusually high concentrations of Th. The pattern of variation of the parent isotopes, {sup 238}U and {sup 232}Th, as well as the daughter isotopes, {sup 234}U, {sup 230}Th, and {sup 228}Th, is systematic within and between the two oases. From the unusually consistent distribution of the {sup 234}U/{sup 238}U activity ratios one can conclude that the samples from both oasesmore » are representative of a two-component mixing system. One component, characterized by low U content and a high {sup 234}U/{sup 238}U activity ratio, is typical of deep artesian systems and probably represents flowthrough water derived from the Nubian highlands to the south. The second component is characterized by a greater U concentration and a low activity ratio. This signature is hypothesized as being derived by leaching of downward infiltrating water during pluvial times. The source of the U may be the uraniferous phosphate strata that overly the sandstone aquifer in both oasis areas. Higher Th values are associated with the artesian flow component of the mixing system and suggests that Th-bearing minerals may be abundant in the Nubian sandstone aquifer. The distribution of {sup 230}Th and {sup 228}Th in the water samples supports this interpretation.« less

Audio-magnetotelluric surveys to constrain the origin of a network of narrow synclines in Eocene limestone, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Tarabees, Elhamy A.; Tewksbury, Barbara J.; Mehrtens, Charlotte J.; Younis, Abdellatif

2017-12-01

Recent work with high resolution satellite imagery has revealed a network of narrow synclines developed during the Oligocene or Miocene over tens of thousands of square kilometers in Eocene limestone of the Thebes Group in the Western Desert of Egypt. The synclines are non-tectonic, and their scale and geometry strongly resemble sag synclines in Qatar that were produced by dissolution of subsurface evaporites and resulting sag of overlying layers. Evaporite dissolution cannot explain the Egypt synclines, because subsurface evaporites of any significance have never been reported in this part of Egypt. In this study, we use audio-magnetotelluric surveys to illuminate the subsurface under the synclines in order to constrain possible models for their formation. We suspected karst dissolution at depth, and, given a modern water table depth of over 400 m, we expected that dry fracture networks and void spaces under the synclines might result in higher electrical resistivities than surrounding coherent limestone. We also anticipated a significant change from high to low resistivity at the contact between the Thebes Group and the underlying Esna Shale at depths of 400 m or more. Instead, we found localized low resistivity zones extending from about 50-100 m below the surface to depths of more than 400 m that are strongly correlated with synclines. We suggest that these localized low resistivity zones are filled with artesian groundwater that has insufficient hydraulic head to rise to the modern topographic surface and that is localized in subsurface voids and collapse breccias produced by dissolution. Sag of overlying limestone layers is a reasonable model for syncline formation but, given the Oligocene/Miocene age of the synclines, dissolution and sag would be unrelated to young groundwater processes.

Groundwater Numerical Modeling, An Application of Remote Sensing, and GIS Techniquies in El Shab area, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Faid, Abdalla; Ismail, Esam

2016-04-01

El Shab region is located in south Darb El Arbaieen, western desert of Egypt. It occupies the area between latitudes 22o 00/ and 22o 30/ North and Longitudes 29o 30/ and 30o 00/ East, from southern border of Egypt to the area north Bir Kuraiym and from the area east of east Owienat to the area west Tushka district, its area about 2750 Km2. The famous features; southern part of Darb El Arbaieen road, G Baraqat El Scab El Qarra, Bir Dibis, Bir El Shab and Bir Kuraiym, Interpretation of soil stratification shows layers that are related to Quaternary and Upper-Lower Cretaceous eras. It is dissected by a series of NE-SW striking faults. The regional groundwater flow direction is in SW-NE direction with a hydraulic gradient is 1m / 2km. Mathematical model program has been applied for evaluation of groundwater potentials in the main Aquifer -Nubian Sandstone- in the area of study. Total period of simulation is 100 years. After steady state calibration, two different scenarios are simulated for groundwater development. 21 production wells are installed at the study area and used in the model, with the total discharge for the two scenarios were 105000m3/d, 210000m3/d. The drawdown was 11.8 m and 23.7 m for the two scenarios in the end of 100 year. Contour maps for water heads and drawdown and hydrographs for piezometric head are represented. The drawdown was less than the half of the saturated thickness (the safe yield case).

Precipitation source inferred from stable isotopic composition of Pleistocene groundwater and carbonate deposits in the western desert of Egypt.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sultan, M.; Sturchio, N.; Hassan, F. A.

1997-01-01

An Atlantic source of precipitation can be inferred from stable isotopic data (H and O) for fossil groundwaters and uranium-series-dated carbonate spring deposits from oases in the Western Desert of Egypt. In the context of available stable isotopic data for fossil groundwaters throughout North Africa, the observed isotopic depletions ({delta}D -72 to -81{per_thousand}; {delta}{sup 18}O -10.6 to -11.5{per_thousand}) of fossil ({ge}32,000 yr B.P.) groundwaters from the Nubian aquifer are best explained by progressive condensation of water vapor from paleowesterly wet oceanic air masses that traveled across North Africa and operated at least as far back as 450,000 yr before themore » present. The values of {delta}{sup 18}O (17.1 to 25.9{per_thousand}) for 45,000- to >450,000-yr-old tufas and vein-filling calcite deposits from the Kharga and Farafra Oases are consistent with deposition from groundwaters having oxygen isotopic compositions similar to those of fossil groundwaters sampled recently at these locations.« less

Remote Sensing and Shallow Geophysical Investigations on Moghra Lake in Northeastern Qattarra Depression, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Khan, S. D.; Fathy, M. S.; Azeem, M. A.

2012-12-01

The Western Desert of Egypt encompasses two thirds of the land area of Egypt and constitutes one of the driest regions of the Sahara. This desert has seven depressions; Siwa, Qattara, Fayium, Bahariya, Farafra, Dakhla and Kharga. These depressions may be the manifestation of old drainage basins with extensive erosion and possibly some tectonic activity. Several oases with freshwater can be found in these depressions. Geological and geophysical investigations in Qattara Depression indicate several buried fluvial channels with flow direction from highlands in southeast to northwest. Moghra Lake at the northeastern tip of Qatarra basin may be a small remnant of a larger paleo-lake including the mouth of a paleo-river. This study probed this area for presence of buried channels that may have fed the larger Moghra paleo-lake. We have used ALOS - PALSAR radar remote sensing data to identify the surface features in this region, such as channels, channel fills, and fractures. In addition, dual polarization PALSAR data (HV, HH) allowed analysis of the near surface geology and assisted in delineating areas of interest for GPR surveys. GPR data along 2D profiles were acquired using the GSSI SIR-3000 system with a 400 MHz antenna that provided images to approximately three meters in depth. All the GPS data were processed using RADAN 6.6 software. A conventional processing flow was used for data processing: The positional correction tool removed the air wave. A range-gain balanced the amplitudes and a final band-pass (50 kHz to 500 kHz) filter was applied to the data. Deconvolution was also applied for highlighting the finer details. In addition, spatial filters were used to attenuate continuous vertical noise. The migrated sections of GPR identified a major paleochannel distributary with two minor channels at the margins. The bedrock of the studied area consists of the Lower Miocene Moghra Formation (sandstone and shale intercalations). The area around the present lake is

The Climate and its Impacts on deterioration and weathering rate of EI-Nadura Temple in El- Kharga Oasis, Western Desert of Egypt.

NASA Astrophysics Data System (ADS)

Ismael, Hossam

2015-04-01

Undoubtedly, El-Kharga Oasis monumental sites are considered an important part of our world's cultural heritage in the South Western Desert of Egypt. These sites are scattered on the floor of the oasis representing ancient civilizations. The Roman stone monuments in Kharga represent cultural heritage of an outstanding universal value. Such those monuments have suffered weathering deterioration. There are various elements which affect the weathering process of stone monuments: climate conditions, shapes of cultural heritages, exposed time periods, terrains, and vegetation around them, etc. Among these, climate conditions are the most significant factor affecting the deterioration of Archeological sites in Egypt. El- Kharga Oasis belongs administratively to the New Valley Governorate. It is located in the southern part of the western desert of Egypt, lies between latitudes 22°30'14" and 26°00'00" N, and between 30°27'00" and 30°47'00" E. The area of El Kharga Oasis covers about 7500 square kilometers. Pilot studies were carried out on the EI-Nadura Temple, composed of sandstones originating from the great sand sea. The major objective of this study is to monitor and measure the weathering features and the weathering rate affecting the building stones forming El-Nadora Roman building rocks in cubic cm. To achieve these aims, the present study used analysis of climatic data such as annual and seasonal solar radiation, Monthly average number of hours of sunshine, maximum and minimum air temperatures, wind speed, which have obtained from actual field measurements and data Meteorological Authority of El-Kharga station for the period 1977 to 2010 (33 years), and from the period 1941-2050 (110 years) as a long term of temperature data. Several samples were collected and examined by polarizing microscopy (PLM), X-ray diffraction analysis (XRD) and scanning electron microscopy equipped with an energy dispersive X-ray analysis system (SEM-EDX). The results were in

Eolian features in the Western Desert of Egypt and some applications to Mars.

USGS Publications Warehouse

El-Baz, F.; Breed, C.S.; Grolier, M.J.; McCauley, J.F.

1979-01-01

Relations of landform types to wind regimes, bedrock composition, sediment supply, and topography are shown by field studies and satellite photographs of the Western Desert. This desert provides analogs of Martian wind-formed features and sand dunes, alternating light and dark streaks, knob 'shadows' and yardangs. Surface particles have been segregated by wind into dunes, sand sheets, and light streaks, that can be differentiated by their grain size distributions, surface shapes, and colors. Throughgoing sand of mostly fine to medium grain size is migrating S in longitudinal dune belts and barchan chains whose long axes lie parallel to the prevailing W winds, but topographic variations such as scarps and depressions strongly influence the zones of deposition and dune morphology. -from Authors

New findings in the Eocene stratigraphy of Siwa-El Qara stretch, north western desert, Egypt

NASA Astrophysics Data System (ADS)

Osman, R.; Orabi, H.

2017-10-01

The Upper Hamra Member of Said and Issawi (1964) is a clastic/carbonate succession at Qor El Hamra east of the Bahariya Oasis in the Western Desert, Egypt. Earlier, the authors changed this member into a new informal name, the Al Humaymat formation (Priabonian) at the Siwa Oasis, which consists generally of carbonate sediments and overlays the mushroom rock of the Mokattam Formation (Late Lutetian). The thickness of the Al Humaymat formation is about 22 m recorded at the El Qara section and at the El Arag section reaches 5 m, where the collected fauna from this formation is represented by larger foraminifera Nummulites fabianii retiatus, Gaziryina aff. pulchellus, Silvestriella tetraedra and Grzybowskia sp. are assigned to Late Eocene (Priabonian). The base of the Al Humaymat formation is composed of grey marl to varicolored small scale tabular cross-bedded limestone, which reflects sheet flood deposits with a great unconformity surface; the middle part is composed of reefal limestone and sandy limestone. The upper part of this formation is characterized by earthy white limestone, which is overlain by very hard brown ferruginous paleosol bands and pockets, which represent distal floodplain deposits. Here it is interesting to notice that the Early and Late Priabonian decrease in depth of the sea over the studied area seems to be a reflection of a global decrease in depth of the sea as suggested from eustatic curves published by Haq et al., l987.

Subsurface brine injection: Proactive approach to close the produced water loop in the western desert of Egypt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farid, E.E.; Nour, M.H.

1996-11-01

In 1988 a major onshore production facility was producing oil from eight formations in six oil fields located in the western desert of Egypt. Two of these formations include active water drive reservoirs, in addition; three reservoirs at that date were receiving water injection to enhance oil recovery. To handle the increasing volumes of the produced water (which is contaminated with oil, production chemicals and other pollutants), three alternatives were investigated: (1) Injection into disposal wells. (2) Dumping in surface disposal pits. (3) Re-injection to waterflood some oil reservoirs. The investigation revealed that the first two options are technically unfavorable,more » also they are conventional Waste Management Technologies (WMT) which provide short-term remedial solution. In contrast, Produced Water Re-Injection (PWRI) is an Environmental Control Technology (ECT) which minimize the environmental impact through process improvements. A state -of-the-art re-injection process was utilized using chemical treatment, gas liberation, settling, filtration and injection. This process represents a combination of two (ECT) methods: Reuse (for water flooding) and Recycling (when brine is redisposed underground). This process reduce the overall volumes of produced water to be disposed, increase the oil reserves, reservoir pressure and oil production and converse the underground water reserve.« less

A recent Mw 4.3 earthquake proving activity of a shallow strike-slip fault in the northern part of the Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Ezzelarab, Mohamed; Ebraheem, Mohamed O.; Zahradník, Jiří

2018-03-01

The Mw 4.3 earthquake of September 2015 is the first felt earthquake since 1900 A.D in the northern part of the Western Desert, Egypt, south of the El-Alamein City. The available waveform data observed at epicentral distances 52-391 km was collected and carefully evaluated. Nine broad-band stations were selected to invert full waveforms for the centroid position (horizontal and vertical) and for the focal mechanism solution. The first-arrival travel times, polarities and low-frequency full waveforms (0.03-0.08 Hz) are consistently explained in this paper as caused by a shallow source of the strike-slip mechanism. This finding indicates causal relation of this earthquake to the W-E trending South El-Alamein fault, which developed in Late Cretaceous as dextral strike slip fault. Recent activity of this fault, proven by the studied rare earthquake, is of fundamental importance for future seismic hazard evaluations, underlined by proximity (∼65 km) of the source zone to the first nuclear power plant planned site in Egypt. Safe exploration and possible future exploitation of hydrocarbon reserves, reported around El-Alamein fault in the last decade, cannot be made without considering the seismic potential of this fault.

Technologies Applied in the Toshka Project of Egypt

ERIC Educational Resources Information Center

Wahby, Wafeek S.

2004-01-01

The Toshka Project, located in Egypt, involves excavating a canal to carry about 380 billion ft[supercript 3] of water every year from Lake Nasser to the Toshka Depression, southwest of Aswan. This will eventually create a new valley to the River Nile in the western desert of Egypt in addition to the currently existing prehistoric river course.…

Crustal modeling of the central part of the Northern Western Desert, Egypt using gravity data

NASA Astrophysics Data System (ADS)

Alrefaee, H. A.

2017-05-01

The Bouguer anomaly map of the central part of the Northern Western Desert, Egypt was used to construct six 2D gravity models to investigate the nature, physical properties and structures of the crust and upper mantle. The crustal models were constrained and constructed by integrating results from different geophysical techniques and available geological information. The depth to the basement surface, from eight wells existed across the study area, and the depth to the Conrad and Moho interfaces as well as physical properties of sediments, basement, crust and upper mantle from previous petrophysical and crustal studies were used to establish the gravity models. Euler deconvolution technique was carried on the Bouguer anomaly map to detect the subsurface fault trends. Edge detection techniques were calculated to outlines the boundaries of subsurface structural features. Basement structural map was interpreted to reveal the subsurface structural setting of the area. The crustal models reveals increasing of gravity field from the south to the north due to northward thinning of the crust. The models reveals also deformed and rugged basement surface with northward depth increasing from 1.6 km to 6 km. In contrast to the basement, the Conrad and Moho interfaces are nearly flat and get shallower northward where the depth to the Conrad or the thickness of the upper crust ranges from 18 km to 21 km while the depth to the Moho (crustal thickness) ranges from 31.5 km to 34 km. The crust beneath the study area is normal continental crust with obvious thinning toward the continental margin at the Mediterranean coast.

The bivalve Placuna (Indoplacuna) miocenica from the Middle Miocene of Siwa Oasis, Western Desert of Egypt: Systematic paleontology, paleoecology, and taphonomic implications

NASA Astrophysics Data System (ADS)

El-Sabbagh, Ahmed M.; El Hedeny, Magdy M.; Rashwan, Mohammed A.; Abdel Aal, Abdel Aal A.

2016-04-01

The present study investigated the epifaunal, free lying bivalve Placuna (Indoplacuna) miocenica (Fuchs, 1883) encountered in the Middle Miocene Marmarica Formation of Siwa Oasis, Western Desert, Egypt, in terms of systematic paleontology, paleoecology and taphonomy. Well to moderately preserved shells of this species were collected from three sections. They have been found embedded in sandy, marly and chalky limestones. Although they are extremely thin and fragile, they occurred as complete disarticulated and articulated valves. Specimens of P. (I.) miocenica are highly accumulated in the north Siwa section forming a coquinoid band (30 cm thick). In addition, they are generally distributed sporadically in different stratigraphic levels within the three studied sequences. Taphonomic observations indicated that these shells were affected by encrustation, bioerosion, disarticulation, fragmentation and abrasion. Moreover, valves of this species suffered minor chipping along their fragile margins. The occurrence of the studied species associated with oysters and other benthic faunal assemblages within carbonate sediments revealed shallow, low energy, warm and intertidal environments with periods of relatively agitated conditions.

Vertebrate paleontological exploration of the Upper Cretaceous succession in the Dakhla and Kharga Oases, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Sallam, Hesham M.; O'Connor, Patrick M.; Kora, Mahmoud; Sertich, Joseph J. W.; Seiffert, Erik R.; Faris, Mahmoud; Ouda, Khaled; El-Dawoudi, Iman; Saber, Sara; El-Sayed, Sanaa

2016-05-01

The Campanian and Maastrichtian stages are very poorly documented time intervals in Africa's record of terrestrial vertebrate evolution. Upper Cretaceous deposits exposed in southern Egypt, near the Dakhla and Kharga Oases in the Western Desert, preserve abundant vertebrate fossils in nearshore marine environments, but have not yet been the focus of intensive collection and description. Our recent paleontological work in these areas has resulted in the discovery of numerous new vertebrate fossil-bearing localities within the middle Campanian Qusier Formation and the upper Campanian-lower Maastrichtian Duwi Formation. Fossil remains recovered from the Campanian-aged Quseir Formation include sharks, rays, actinopterygian and sarcopterygian fishes, turtles, and rare terrestrial archosaurians, including some of the only dinosaurs known from this interval on continental Africa. The upper Campanian/lower Maastrichtian Duwi Formation preserves sharks, sawfish, actinopterygians, and marine reptiles (mosasaurs and plesiosaurs). Notably absent from these collections are representatives of Mammalia and Avialae, both of which remain effectively undocumented in the Upper Cretaceous rocks of Africa and Arabia. New age constraints on the examined rock units is provided by 23 nannofossil taxa, some of which are reported from the Duwi Formation for the first time. Fossil discoveries from rock units of this age are essential for characterizing the degree of endemism that may have developed as the continent became increasingly tectonically isolated from the rest of Gondwana, not to mention for fully evaluating origin and diversification hypotheses of major modern groups of vertebrates (e.g., crown birds, placental mammals).

Characterization of magnetic spherical fractions in sand deposits for interpretation of environmental change around the El- Zayyan temple, Kharga Oasis, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Watanabe, Makiko; Koizumi, Natsuko; Kato, Sayuri; Kikuchi, Ryohei; Kamei, Hiroyuki

2014-05-01

Desertification in North Africa has rapidly advanced over the last 6,000 years. Such environmental changes began in the Early Dynastic Period of Egypt (4200 - 3150 BC), and the occupation of Achaemenid Persian and Roman cultures in Egypt occurred under even drier climates. Kharga is the largest oasis of the five oases, located in the western desert of Egypt that contains a treasure trove of archaeological resources. This oasis has been highlighted to promote resource exploration and development of archaeological tourism since the 1980's. The El-Zayyan temple is located 27 km south of the central Kharga oasis. Zayyan was once called 'Tchonemyris', which has connection with the means of 'huge well' in Greek. Although major portions of the temple were rebuilt in 140 AD during the rule of the Roman Emperor Antoninus Pius, this temple is considered to be originally built in the Ptolemaic period (4c-1c BC). It is likely that the area had a sufficient water supply in the past as the El-Zayyan temple stands at the lowest point (-18 m a.s.l.) in the Kharga oasis. Furthermore, the El-Ghueita temple that stands on a hill top at 68.5 m a.s.l., 4 km northward from the El-Zayyan temple, has given name that means 'beautiful garden' in Greek. From these facts, we can imagine that the past landscape of this area contained green surroundings. The El-Ghueita temple was well known as a production centre of high quality wine since the mid-Dynastic age (2050 -1786 BC). As this area is currently arid, it is expected that there were irrigation facilities to maintain the vast farm land during the ancient period. To deepen our knowledge of how people developed their technologies and conducted their life within the natural environment of a drastic drying period, understanding the process of environmental change on a region scale is necessary. The aim of this study was to extract proxies from sand deposits in the western desert area to estimate the change in the environment. We examined the

ESR analyses for herbivore teeth and molluscs from Kharga, Dakhleh, and Bir Tarfawi Oases: Constraining water availability and hominin paleolithic activity in the Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Blackwell, B. A. B.; Skinner, A. R.; Smith, J. R.; Hill, C. L.; Churcher, C. S.; Kieniewicz, J. M.; Adelsberger, K. A.; Blickstein, J. I. B.; Florentin, J. A.; Deely, A. E.; Spillar, K. V.

2017-12-01

Today, Bir Tarfawi, Kharga and Dakhleh Oases all sit in Egypt's hyperarid Western Desert. A dearth of naturally occurring surface water coupled with ≤ 0.1 mm/y of precipitation, and evaporation rates > 2 m/y make Bir Tarfawi uninhabitable today, while Dakhleh and Kharga depend on borehole water to support human inhabitation. Yet in scattered locations dotting the Quaternary surfaces and deposits near each oasis, Paleolithic artefacts, fossil ungulate teeth, and snails record times when surface water did exist in wetlands, small ponds, and even large lakes. At Bir Tarfawi in Marine Isotope Stages (MIS) 5, 7, and 13, wetlands or small lakes supported freshwater snails, large herbivores, and hominins. Dakhleh Oasis hosted a large lake in MIS 6 that provided a deep reliable water supply for many millennia subsequently. ESR dates on fossils and tufa dates show thriving lacustrine and terrestrial ecosystems at Dakhleh during MIS 5, 7, 9, 11, and 17, and in shorter episodes in MIS 1, 2, 3, 6, and 12. At Kharga Oasis, springs discharged along the Libyan Escarpment edge, but the water was ponded in small basins dammed within tufa deposits. These dated deposits and fossils attest that water existed there in MIS 2-11, and one spot dating to ∼ 2.3 Ma. This proxy evidence suggest that, thanks to higher rainfall and/or groundwater tables, sufficient water persisted for much of the Pleistocene, supporting food resources, like large herbivores and molluscs, to thrive and enabling hominin habitation. and activity in the Western Desert.

Stratigraphy, facies analysis and depositional environments of the Upper Unit of Abu Roash "E" member in the Abu Gharadig field, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Hewaidy, Abdel Galil; Elshahat, O. R.; Kamal, Samy

2018-03-01

Abu Roach "E" member is of an important hydrocarbon reservoir-producing horizon in the Abu Gharadig Field (north Western Desert, Egypt). This study is used to build facies analysis and depositional environments model for the Upper Unit of the Abu Roash "E" member in Abu Gharadig Field. This target has been achieved throughout the sedimentological, wire line logs, lithostratigraphic and biostratigraphic analyses of more than 528 feet cores. The high-resolution biostratigraphic analysis provides a calibration for the paleo-bathymetry and depositional environmental interpretations. Biozonation and lithostratigraphic markers are used to constrain stratigraphic correlation. Integration between the core description and petorographic microfacies analysis by microscope examination provide an excellent indication for the rock types and depositional environments. Five depositional facies types are detected including carbonate inner ramp, tidal flats, tidal channels, supra-tidal and tide dominated delta facies. This model helps in the understanding of the Upper Unit of Abu Roash "E" member reservoir distribution as well as lateral and vertical facies changes that contribute to the development strategy for the remaining hydrocarbon reserves for this important oil reservoir.

Egypt/United States cooperative energy assessment. Volume II, Annex 1. Energy resources of Egypt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-04-01

This report contains the findings and recommendations of the US Geological Survey geologists assigned to survey Egypts indigenous energy resources. Data on oil and gas, coal and oil shale, uranium and thorium, geothermal energy, water resources, and energy related minerals are presented. Thirty-nine oil and gas fields have been discovered in Egypt, proven reserves of oil were estimated to be 1,559,000,000 barrels in 1976. The Egyptian government hopes to attain a production rate of 1 million barrels a day in 1982. While the Gulf of Suez basin holds the most immediate prospects, the most promising frontier regions are the unexploredmore » broad expanses of the Western Desert, the Nile Basin and the Northern Sinai while oil shales have been found in Egypt, they are only 10 to 15 feet thick and their hydrocarbon content is low. Recovery would not be economic. Coal deposits contain reserves estimated at 95 to 112 million tons. Only 1 deposit is deemed workable under present conditions of technology and economy. No uranium and thorium are being produced however geological conditions appear favorable for finding uranium deposits using appropriate programs of prospecting, exploration and development. The potential for development of low-level sources of geothermal energy in Egypt is good; there is no evidence of a high-temperature source or a vapor-dominated system. The Nile is the primary source of water. In the western desert, the Nubian aquifer supplies water for irrigation. Energy related minerals are generally found in uneconomic concentrations or not at all. However, deposits of material used in cement making and some iron ore for steel making are available. Deposits of manganese may become available upon return of the Sinai to Egypt. 44 figures, 24 tables. (DMC)« less

Petrophysical evaluation of the hydrocarbon potential of the Lower Cretaceous Kharita clastics, North Qarun oil field, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Teama, Mostafa A.; Nabawy, Bassem S.

2016-09-01

Based on the available well log data of six wells chosen in the North Qarun oil field in the Western Desert of Egypt, the petrophysical evaluation for the Lower Cretaceous Kharita Formation was accomplished. The lithology of Kharita Formation was analyzed using the neutron porosity-density and the neutron porosity-gamma ray crossplots as well as the litho-saturation plot. The petrophysical parameters, include shale volume, effective porosity, water saturation and hydrocarbon pore volume, were determined and traced laterally in the studied field through the iso-parametric maps. The lithology crossplots of the studied wells show that the sandstone is the main lithology of the Kharita Formation intercalated with some calcareous shale. The cutoff values of shale volume, porosity and water saturation for the productive hydrocarbon pay zones are defined to be 40%, 10% and 50%, respectively, which were determined, based on the applied crossplots approach and their limits. The iso-parametric contour maps for the average reservoir parameters; such as net-pay thickness, average porosity, shale volume, water saturation and the hydrocarbon pore volume were illustrated. From the present study, it is found that the Kharita Formation in the North Qarun oil field has promising reservoir characteristics, particularly in the northwestern part of the study area, which is considered as a prospective area for oil accumulation.

Trypanosoma mega (Kinetoplastida) from Bufo viridis in Siwah Oasis, Egypt.

PubMed

Ashour, A A; Gaafar, N A

1997-04-01

A large pleomorphic trypanosome, identified as Trypanosoma mega, is described from the toad Bufo viridis collected from Siwah Oasis at the Western Desert of Egypt. The prevalence of the trypanosome is 83.3%. Three trypanosome forms are described, small, intermediate and large stumpy form. Observations were also made on the lysed (diffused) trypanosomes. This is the first record of T. mega from B. viridis in Egypt which represents a new host and new geographical location. The measurements of the present trypanosome are given and compared with related forms previously described from Egypt.

Joint by Design: The Western Desert Campaign

DTIC Science & Technology

2015-05-21

levels, he knew he would be unable to hold his tenuous position indefinitely. Under a full moon that glinted off the desert sand on the night of...treacherous minefields and loose sand under heavy fire from coalition aircraft and artillery. The slow movement further depleted his precious fuel...shifting sands .2 One Allied commander wrote, “Not only was Rommel’s bid for Egypt ended, but he was totally and finally defeated. He would never

Electrical and geochemical properties of tufa deposits as related to mineral composition in the South Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Gomaa, Mohamed M.; Abou El-Anwar, Esmat A.

2015-06-01

The geochemical, petrographical, and electrical properties of rocks are essential to the investigation of the properties of minerals. In this paper we will try to present a study of the A. C. electrical properties of carbonate rock samples and their relation to petrographical and geochemical properties. Samples were collected from four formations from the Bir Dungul area, in the South Western Desert, Egypt. The electrical properties of the samples were measured using a non-polarizing electrode, at room temperature (~28 °C), and at a relative atmospheric humidity of (~45%), in the frequency range from 42 Hz to 5 MHz. The changes in the electrical properties were argued to the change in mineral composition. Generally, the electrical properties of rocks are changed due to many factors e.g., grain size, mineral composition, grain shape and inter-granular relations between grains. The dielectric constant of samples decreases with frequency, and increases with conductor concentration. Also, the conductivity increases with an increase of continuous conductor paths between electrodes. The petrographical and geochemical studies reveal that the deposition of the tufa deposits occurred in shallow lakes accompanied by a high water table, an alkaline spring recharge and significant vegetation cover. Diagenetically, tufa deposits were subjected to early and late diagenesis. Petrography and geochemistry studies indicated that the area of tufa deposits was deposited under the control of bacterial activity. Geochemically, the Sr content indicates that the tufa deposits formed from dissolved bicarbonate under the control of microbes and bacterial activity.

Origin and recharge rates of alluvial ground waters, Eastern Desert, Egypt.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sultan, M.; Gheith, H.; Sturchio, N. C.

2002-04-12

Stable isotope and tritium analyses of shallow ground waters in the Eastern Desert of Egypt showed that the waters were derived largely by evaporation of regional precipitation and at least partly from precipitation in the past 45 y. To estimate the ground water recharge rate, we developed an integrated hydrologic model based on satellite data, geologic maps, infiltration parameters, and spatial rainfall distribution. Modeling indicated that during a severe 1994 storm, recharge through transmission loss in Wadi El-Tarfa was 21% of the precipitation volume. From archival precipitation data, we estimate that the annual recharge rate for the El-Tarfa alluvial aquifermore » is 4.7 x 10{sup 6} m{sup 3}. Implications for the use of renewable ground waters in arid areas of Egypt and in neighboring countries are clear.« less

Static reservoir modeling of the Bahariya reservoirs for the oilfields development in South Umbarka area, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Abdel-Fattah, Mohamed I.; Metwalli, Farouk I.; Mesilhi, El Sayed I.

2018-02-01

3D static reservoir modeling of the Bahariya reservoirs using seismic and wells data can be a relevant part of an overall strategy for the oilfields development in South Umbarka area (Western Desert, Egypt). The seismic data is used to build the 3D grid, including fault sticks for the fault modeling, and horizon interpretations and surfaces for horizon modeling. The 3D grid is the digital representation of the structural geology of Bahariya Formation. When we got a reasonably accurate representation, we fill the 3D grid with facies and petrophysical properties to simulate it, to gain a more precise understanding of the reservoir properties behavior. Sequential Indicator Simulation (SIS) and Sequential Gaussian Simulation (SGS) techniques are the stochastic algorithms used to spatially distribute discrete reservoir properties (facies) and continuous reservoir properties (shale volume, porosity, and water saturation) respectively within the created 3D grid throughout property modeling. The structural model of Bahariya Formation exhibits the trapping mechanism which is a fault assisted anticlinal closure trending NW-SE. This major fault breaks the reservoirs into two major fault blocks (North Block and South Block). Petrophysical models classified Lower Bahariya reservoir as a moderate to good reservoir rather than Upper Bahariya reservoir in terms of facies, with good porosity and permeability, low water saturation, and moderate net to gross. The Original Oil In Place (OOIP) values of modeled Bahariya reservoirs show hydrocarbon accumulation in economic quantity, considering the high structural dips at the central part of South Umbarka area. The powerful of 3D static modeling technique has provided a considerable insight into the future prediction of Bahariya reservoirs performance and production behavior.

Geochemical water signature in the Bahariya Depression, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Sciarra, Alessandra; Mazzini, Adriano; Lupi, Matteo; Hammed, Mohammed S.

2017-04-01

The Bahariya Oasis is located about 200 km SW of Cairo in the central part of the Western Desert of Egypt. It occupies a sub-elliptic 40 km wide depression stretching NE-SW for approximately 90 km. The Bahariya Oasis has been targeted for numerous geological studies on structural geology, stratigraphy, and iron ore deposits. The oasis was characterized since the Roman times by the presence of natural hydrothermal springs venting water from the relatively shallow Nubia Sandstone formation. Inside the depression are visible numerous circular concentric features that morphologically resemble the hydrothermal vent complexes observed at igneous provinces in other localities of the planet. In order to investigate the origin and the mechanisms of formation of these features, we conducted a fieldwork survey as well as fluids sampling from the available well sites. The aim was to constrain the origin of the fluids that potentially triggered or facilitated the formation of the concentric structures observed on the field. This study presents the geochemical results of groundwaters and soil gas samples. Ten samples were collected from deep wells present in the area. In particular, 8 warm waters were collected by wells between 800 m and 1200 m deep. The measured temperatures at these sites range from 36.5 °C to 52.3°C, while the coldest wells have temperatures ranging from 27.9 °C to 36.5°C. For each sample collected from the wells we analyzed the major, minor and trace elements, dissolved gases (He, Ne, H2, O2, N2, CH4, CO2, Rn), and relative isotopic values. In the areas around the wells we measured CO2 and CH4 fluxes as well as radon activity. Overall, the water showed a high value of dissolved Rn, ranging from 9 to 43 Bq/l, and dissolved CO2 ranging from 5.9 to 17.4 cc/l. The waters show a radiogenic signature of isotopic helium, highlighting very prolonged interaction with local crust enriched in radiogenic elements. The isotopic values of δ18O and δD show a clear

Mesozoic evolution of northeast African shelf margin, Libya and Egypt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aadland, R.K.; Schamel, S.

1989-03-01

The present tectonic features of the northeast African shelf margin between the Nile delta and the Gulf of Sirte are products of (1) precursory late Paleozoic basement arches, (2) early Mesozoic rifting and plate separation, and (3) Late Cretaceous structural inversion. The 250 km-wide and highly differentiated Mesozoic passive margin in the Western Desert region of Egypt is developed above a broad northwest-trending Late Carboniferous basement arch. In northeastern Libya, in contrast, the passive margin is restricted to just the northernmost Cyrenaica platform, where subsidence was extremely rapid in the Jurassic and Early Cretaceous. The boundary between the Western Desertmore » basin and the Cyrenaica platform is controlled by the western flank of the basement arch. In the middle Cretaceous (100-90 Ma), subsidence accelerated over large areas of the Western desert, further enhancing a pattern of east-west-trending subbasins. This phase of rapid subsidence was abruptly ended about 80 Ma by the onset of structural inversion that uplifted the northern Cyrenaica shelf margin and further differentiated the Western Desert subbasin along a northeasterly trend.« less

Constraints from Mesozoic siliciclastic cover rocks and satellite image analysis on the slip history of regional E-W faults in the southeast Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Tewksbury, Barbara J.; Mehrtens, Charlotte J.; Gohlke, Steven A.; Tarabees, Elhamy A.; Hogan, John P.

2017-12-01

In the southeast Western Desert of Egypt, a prominent set of E-W faults and co-located domes and basins involve sedimentary cover rock as young as the early Eocene. Although earlier Mesozoic slip on faults in southern Egypt has been widely mentioned in the literature and attributed to repeated reactivation of basement faults, evidence is indirect and based on the idea that regional stresses associated with tectonic events in the Syrian Arc would likely have reactivated basement faults in south Egypt in dextral strike slip during the Mesozoic as well as the Cenozoic. Here, we present direct evidence from the rock record for the sequence of development of features along these faults. Southwest of Aswan, a small structural dome in Mesozoic Nubia facies rocks occurs where the Seiyal Fault bends northward from west to east. The dome is cut by strands of the Seiyal Fault and a related set of cataclastic deformation bands showing dominantly right lateral strike slip, as well as by younger calcite veins with related patchy poikilotopic cement. High resolution satellite image analysis of the remote southwest Kharga Valley shows a similar sequence of events: older structural domes and basins located where E-W faults bend northward from west to east, right lateral offset of domes and basins along the E-W faults, and two sets of deformation band faults that lack co-located domes and basins. We suggest that field data, image analysis, and burial depth estimates are best explained by diachronous development of features along the E-W fault system. We propose that Late Mesozoic right lateral strike slip produced domes and basins in Nubia facies rocks in stepover regions above reactivated basement faults. We further suggest that the extensively linked segments of the E-W fault system in Nubia facies rocks, plus the deformation band systems, formed during the late Eocene when basement faults were again reactivated in dominantly right lateral strike slip.

Soil seed bank in different habitats of the Eastern Desert of Egypt.

PubMed

Gomaa, Nasr H

2012-04-01

The floristic composition and species diversity of the germinable soil seed bank were studied in three different habitats (desert salinized land, desert wadi, and reclaimed land) in the Eastern Desert of Egypt. Moreover, the degree of similarity between the seed bank and the above-ground vegetation was determined. The seed bank was studied in 40 stands representing the three habitats. Ten soil samples (each 25 × 20 cm and 5 cm depth) were randomly taken per stand. The seed bank was investigated by the seedling emergence method. Some 61 species belonging to 21 families and 54 genera were identified in the germinable seed bank. The recorded species include 43 annuals and 18 perennials. Ordination of stands by Detrended Correspondence Analysis (DCA) indicates that the stands of the three habitats are markedly distinguishable and show a clear pattern of segregation on the ordination planes. This indicates variations in the species composition among habitats. The results also demonstrate significant associations between the floristic composition of the seed bank and edaphic factors such as CaCO3, electrical conductivity, organic carbon and soil texture. The reclaimed land has the highest values of species richness, Shannon-index of diversity and the density of the germinable seed bank followed by the habitats of desert wadi and desert salinized land. Motyka's similarity index between the seed bank and the above-ground vegetation is significantly higher in reclaimed land (75.1%) compared to desert wadi (38.4%) and desert salinized land (36.5%).

Seismic data interpretation for hydrocarbon potential, for Safwa/Sabbar field, East Ghazalat onshore area, Abu Gharadig basin, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Hameed El Redini, Naser A.; Ali Bakr, Ali M.; Dahroug, Said M.

2017-12-01

Safwa/Sabbar oil field located in the East Ghazalat Concession in the proven and prolific Abu Gharadig basin, Western Desert, Egypt, and about 250 km to the southwest of Cairo, it's located in the vicinity of several producing oil fields ranging from small to large size hydrocarbon accumulation, adjacent to the NW-SE trending major Abu Gharadig fault which is throwing to the Southwest. All the geological, "structure and stratigraphic" elements, have been identified after interpreting the recent high quality 3D seismic survey for prospect generation, evaluation and their relation to the hydrocarbon exploration. Synthetic seismograms have been carried out for all available wells to tie horizons to seismic data and to define the lateral variation characters of the beds. The analysis has been done using the suitable seismic attributes to understand the characteristics of different types of the reservoir formations, type of trap system, identify channels and faults, and delineating the stratigraphic plays of good reservoirs such as Eocene Apollonia Limestone, AR "F", AR "G" members, Upper Bahariya, Jurassic Khatatba Sandstone, upper Safa and Lower Safa Sandstone. The top Cenomanian Bahariya level is the main oil reservoir in the Study area, which consist of Sandstone, Siltstone and Shale, the thickness is varying from 1 to 50 ft along the study area. In addition to Upper-Bahariya there are a good accessibility of hydrocarbon potential within the Jurassic Khatatba Sandstone and the Eocene Apollonia Limestone. More exploring of these reservoirs are important to increase productivity of Oil and/or Gas in the study area.

Application and calibration of the subsurface mapping capability of SIR-B in desert regions

NASA Technical Reports Server (NTRS)

Schaber, G. G.; Mccauley, J. F.; Breed, C. S.; Grolier, M. J.; Issawi, B.; Haynes, C. V.; Mchugh, W.; Walker, A. S.; Blom, R.

1984-01-01

The penetration capability of the shuttle imaging radar (SIR-B) sensor in desert regions is investigated. Refined models to explain this penetration capability in terms of radar physics and regional geologic conditions are devised. The sand-buried radar-rivers discovered in the Western Desert in Egypt and Sudan are defined. Results and procedures developed during previous SIR-A investigation of the same area are extrapolated.

Genetic Aspects of Gold Mineralization at Some Occurrences in the Eastern Desert of Egypt

NASA Astrophysics Data System (ADS)

Abd El Monsef, M.; Slobodník, M.; Salem, I. A.

2012-04-01

The Eastern Desert of Egypt is well known as a gold-mining area since ancient times, there're more than 95 gold deposits and occurrences spread the whole area covered by the basement rocks of Precambrian age. The basement rocks of the Eastern Desert of Egypt constitute the Nubian Shield that has formed a continuous part of the Arabian-Nubian Shield before the opening of Red Sea (Oligocene-Early Miocene). Commonly, the system of gold-bearing quartz veins in the Eastern Desert is clearly structural controlled related to brittle-ductile shear zones that mostly developed during late deformational stages of the evolution history for basement rocks in the Eastern Desert. This running study principally aims to contribute the mineral resource potential of the gold deposits in Egypt, so particularly Fatira, Gidami and Atalla occurrences have been involved into a comprehensive study based on field, structural, mineralogical, geochemical and genetic investigations. It is intended to better understanding for the characteristics, distribution controls, conditions and age of mineralization in relation to the age of the hosting rocks intrusion to find if there're genetic links between the gold mineralization and the evolution of the host intrusive complex. Several authors suggested that the gold mineralization was related to the intrusion of the (postorogenic) Younger granites. Other authors interpret these deposits as products of hydrothermal activity induced either by metamorphism or cooling effects of early Paleozoic magmatism or as combined metamorphic/magmatic episodes. The prime focus will be directed to the ore itself and the associated hydrothermal alteration zones based on detailed maps and well-distributed samples network and geochemical anomalies distribution. The laboratory studies included microscopic examination (reflecting and transmitting microscopy) to allow for determination of the hosting rocks types and mineralogical changes related to the gold mineralization

Sedimentology of the fluvial and fluvio-marine facies of the Bahariya Formation (Early Cenomanian), Bahariya Oasis, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Khalifa, M. A.; Catuneanu, O.

2008-05-01

The Lower Cenomanian Bahariya Formation in the Bahariya Oasis, Western Desert, Egypt, was deposited under two coeval environmental conditions. A fully fluvial system occurs in the southern portion of the Bahariya Oasis, including depositional products of meandering and braided streams, and a coeval fluvio-marine setting is dominant to the north. These deposits are organized into four unconformity-bounded depositional sequences, whose architecture is shaped by a complex system of incised valleys. The fluvial portion of the lower two depositional sequences is dominated by low-energy, meandering systems with a tabular geometry, dominated by overbank facies. The fluvial deposits of the upper two sequences represent the product of sedimentation within braided streams, and consist mainly of amalgamated channel-fills. The braided fluvial systems form the fill of incised valleys whose orientation follows a southeast-northwest trending direction, and which truncate the underlying sequences. Four sedimentary facies have been identified within the braided-channel systems, namely thin-laminated sandstones (Sh), cross-bedded sandstones (Sp, St), massive ferruginous sandstones (Sm) and variegated mudstones (Fm). The exposed off-channel overbank facies of the meandering systems include floodplain (Fm) and crevasse splay (Sl) facies. The fluvio-marine depositional systems consist of interbedded floodplain, coastal and shallow-marine deposits. The floodplain facies include fine-grained sandstones (Sf), laminated siltstones (Stf) and mudstones (Mf) that show fining-upward cycles. The coastal to shallow-marine facies consist primarily of mudstones (Mc) and glauconitic sandstones (Gc) organized vertically in coarsening-upward prograding cyclothems topped by thin crusts of ferricrete (Fc). The four depositional sequences are present across the Bahariya Oasis, albeit with varying degrees of preservation related to post-depositional erosion associated with the formation of sequence

Characteristics of NORM in the oil industry from eastern and western deserts of Egypt.

PubMed

Shawky, S; Amer, H; Nada, A A; El-Maksoud, T M; Ibrahiem, N M

2001-07-01

Naturally occurring radionuclides (NORs) from the 232Th- and 238U-series, which are omnipresent in the earth's crust, can be concentrated by technical activities, particularly those involving natural resources. Although, a great deal of work has been done in the field of radiation protection and remedial action on uranium and other mines, recent concern has been devoted to the hazard arising from naturally occurring radioactive materials (NORM) in oil and gas facilities. NORM wastes associated with oil and gas operations from scale deposits, separated sludge and water at different oil fields in the eastern and western deserts were investigated. Concentrations of the uranium, thorium, and potassium (40K) series have been determined from high-resolution gamma-ray spectrometry. Total uranium content of samples was determined using laser fluorimetry. The levels of radioactivity were mainly due to enhanced levels of dissolved radium ions. Only minute quantities of uranium and thorium were present. The disequilibrium factor for 238U/226Ra has been determined.

High frequency peritidal cycles in the lower member of the Late Cretaceous (Turonian, Coniasian-Santonian) El Hefhuf Formation, Bahariya Oases, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Khalifa, M. A.; Tanner, Lawrence H.

2017-06-01

Carbonate lithofacies of the lower member of the El Hefhuf Formation (Turonian, Coniasian-Santonian) in the Bahariya Oases, Western Desert of Egypt comprise dolostone, burrowed dolostone, cherty dolostone, calcareous dedolostone, dolomitic quartzose lime-mudstone, and caliche. The dolostone and cherty dolostone formed in intertidal to supratidal environments, while dedolostone and caliche were formed during subaerial exposure. The dolomitic quartzose lime-mudstone was deposited in a restricted subtidal environment. Stable isotope analyses of the dolostone lithofacies are consistent with dolomitization by normal marine to evaporatively enriched dolomitizing fluids with only slight mixing of meteoric water. Therefore, dolomitization occurred in the intertidal and supratidal environments immediately following deposition. The dolostone and cherty dolostone lithofacies display pronounced cyclicity at the sub-meter scale, with individual cycles consisting of one (monolithic), two (diad) or at most three (triad) lithofacies. Most of all cycles show evidence of subaerial exposure at the top, such as brecciations, and many cycles are capped by calcareous palaeosol layers (caliche). In the absence of evidence for cycle periods at Milankovitch-scale frequencies, we reject orbital forcing as the cause of the cyclicity and suggest instead autocyclic depositional processes in the peritidal environment as the primary control on cyclicity, possibly modified by eustatic fluctuations at periods longer than the cycles recorded here. The significance of this study is to suggest formation of dolomite cycles due to high-frequency in sea level with intermittent subaerial exposure.

Chemical and isotopic constraints on the origin of Wadi El-Tarfa ground waters, Eastern Desert, Egypt.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sultan, M.; Sturchio, N. C.; Abdel Hady, Y.

2000-10-01

We evaluated the use of the renewable ground water resources of the Eastern Desert to develop sustainable agriculture in Upper Egypt, an alternative that could alleviate some of Egypt's dependence on water from the Nile River. Ground water from shallow aquifers in the Eastern Desert of Egypt, near the intersection of Wadi El-Tarfa and the Nile River, was analyzed for chemical compositions, stable isotope ratios, and tritium activities. The ground water has a range in total dissolved solids of 300 to 5000 mg/L. Values of {delta}D and {delta}{sup 18}O range from -10 to +34 %o and -2 to +5.2 %o,more » respectively, and defines a line having a slope of 5.7 that intersects the meteoric water line at about {delta}D = -15% on a plot of 8D versus {delta}{sup 18}O. These findings indicate that the water might have been derived by a combination of evaporation of and salt addition to regional precipitation. Only one sample could have been derived directly by evaporation and transpiration of modern Nile River water. Salinization of the ground water could have occurred through dissolution of marine aerosol dry fallout, carbonate minerals, gypsum, and other trace evaporitic minerals at and near the ground surface. Tritium activities ranged from 0.04 to 12.9 TU (tritium unite), indicating that all but one of the samples were derived at least partly from precipitation that occurred within the last 45 years. These data indicate that Nubian Aquifer paleowater is not a significant component of the shallow aquifers of this portion of the Eastern Desert. The most likely source of this ground water is sporadic flash flood events yielding locally voluminous recharge that accumulates in coarse sediments and fractured rock beneath alluvial channels. The magnitude of this renewable ground water resource and its potential for supporting sustainable agriculture require further investigation.« less

Crustal structure of northern Egypt from joint inversion of receiver functions and surface wave dispersion velocities

NASA Astrophysics Data System (ADS)

Badawy, Ahmed; Hegazi, Mona; Gaber, Hanan; Korrat, Ibrahim

2018-05-01

In this study, we used a combined inversion of body wave receiver functions and surface wave dispersion measurements to provide constraints on the crustal structure of northern Egypt. The two techniques are complementary to each other: receiver functions (RFs) are sensitive to shear-wave velocity contrasts, while surface wave dispersion (SWD) measurements are sensitive to finite variations of shear-wave velocity with depth. A database of 122 teleseismic events digitally recorded by the Egyptian National Seismological Network (ENSN) stations has been used as well. To enhance the resulting RFs at each ENSN station, the H-k stacking method was applied. A joint inversion process between the resulting receiver functions and the surface wave dispersion curves was applied as well. We have produced three averaged velocity structure models for distinct geographic and tectonic provinces namely Sinai, eastern desert, and western desert from east to the west respectively. These models will deeply help in estimation the epicenter distance of earthquake, focal mechanism solutions, and earthquake hazard analysis in northern Egypt. An obvious image of the subsurface structure has been determined which shows that generally the crustal structure of northern Egypt consists of three layers covered with a sequence of sediments that differs in thickness from across the region except in the Sharm area where the sedimentary cover is absent. The obtained results indicate that crustal thickness differs from east to west and reaches its maximum value of about 36 km at Siwa station (SWA) in the western desert and its minimum value of about 28 km at Sharm station (SHR) of the southern tip of the Sinai Peninsula. The Vp/Vs ratio varies between 1.71 and 2.07 in northern Egypt. Generally, the high values (1.93) of (Vp/Vs) at SWA station may reflect the well-known rich aquifer with fully saturated sediments of the Swia Oasis in the Western Desert. Moreover, the highest value (2.07) of (Vp/Vs) at

Crustal structure of northern Egypt from joint inversion of receiver functions and surface wave dispersion velocities

NASA Astrophysics Data System (ADS)

Badawy, Ahmed; Hegazi, Mona; Gaber, Hanan; Korrat, Ibrahim

2018-01-01

In this study, we used a combined inversion of body wave receiver functions and surface wave dispersion measurements to provide constraints on the crustal structure of northern Egypt. The two techniques are complementary to each other: receiver functions (RFs) are sensitive to shear-wave velocity contrasts, while surface wave dispersion (SWD) measurements are sensitive to finite variations of shear-wave velocity with depth. A database of 122 teleseismic events digitally recorded by the Egyptian National Seismological Network (ENSN) stations has been used as well. To enhance the resulting RFs at each ENSN station, the H-k stacking method was applied. A joint inversion process between the resulting receiver functions and the surface wave dispersion curves was applied as well. We have produced three averaged velocity structure models for distinct geographic and tectonic provinces namely Sinai, eastern desert, and western desert from east to the west respectively. These models will deeply help in estimation the epicenter distance of earthquake, focal mechanism solutions, and earthquake hazard analysis in northern Egypt. An obvious image of the subsurface structure has been determined which shows that generally the crustal structure of northern Egypt consists of three layers covered with a sequence of sediments that differs in thickness from across the region except in the Sharm area where the sedimentary cover is absent. The obtained results indicate that crustal thickness differs from east to west and reaches its maximum value of about 36 km at Siwa station (SWA) in the western desert and its minimum value of about 28 km at Sharm station (SHR) of the southern tip of the Sinai Peninsula. The Vp/Vs ratio varies between 1.71 and 2.07 in northern Egypt. Generally, the high values (1.93) of (Vp/Vs) at SWA station may reflect the well-known rich aquifer with fully saturated sediments of the Swia Oasis in the Western Desert. Moreover, the highest value (2.07) of (Vp/Vs) at

Oil and gas exploration in Egypt past, present, and future

DOE Office of Scientific and Technical Information (OSTI.GOV)

Halim, M.A.

1995-08-01

Egypt was among the early countries in which exploration for hydrocarbons took place. Back to 1886 when the first oil discovery was achieved and since then exploration operations were carried out covering almost every prospective area in Egypt. The history of oil exploration in Egypt passed through six stages, each of which is characterized by its own activities and reflects the impact of certain developments not only in the applied exploration techniques, but also in the work style and prevailing exploration concepts, in addition to the development in the agreement terms. Six areas could add new oil and gas reservesmore » to Egypt, namely: N. Sinai (onshore and offshore); Nile Delta (onshore and offshore); Western Desert (onshore and offshore); Nile Valley; Red Sea; and the Gulf of Aqaba. Such areas have the prerequisites for commercial oil and/or gas accumulations including potential source rocks, good reservoirs and adequate traps in addition to effective seals. It is believed that the undiscovered oil and gas reserves of Egypt could be several times that which have been discovered so far.« less

Groundwater studies in arid areas in Egypt using LANDSAT satellite images

NASA Technical Reports Server (NTRS)

Elshazly, E. M.; Abdelhady, M. A.; Elshazly, M. M.

1977-01-01

Various features are interpreted which have strong bearing on groundwater in the arid environment. These include the nature of geological and lithologic units, structural lineaments, present and old drainage systems, distribution and form of water pools, geomorphologic units, weathering surfaces and other weathering phenomena, desert soils, sand dunes and dune sand accumulations, growths of natural vegetation and agriculture, and salt crusts and other expressions of salinization. There are many impressive examples which illustrate the significance of satellite image interpretation on the regional conditions of groundwater which could be traced and interconnected over several tens or even several hundreds of kilometers. This is especially true in the northern Western Desert of Egypt where ground water issuing from deep strata comes to the surface along ENE-WSW and ESE-WNW fault lines and fracture systems. Another striking example is illustrated by the occurrence of fresh to brackish groundwater on the Mediterranean Sea Coastal Zone of the Western Desert where the groundwater is found in the form of lenses floating on the saline sea water.

Multiprocess evolution of landforms in the Kharga Region, Egypt: Applications to Mars

NASA Technical Reports Server (NTRS)

Breed, C. S.; Mccauley, J. F.; Grolier, M. J.

1984-01-01

In order to understand better the polygenetic evolution of landforms on the martian surface, field studies were conducted in and around the Kharga Depression, Egypt. The Kharga region, on the eastern edge of Egypt's Western Desert, was subject to erosion under mostly hyperarid climatic conditions, punctuated by brief pluvial episodes of lesser aridity, since early Pleistocene time. The region contains numerous landforms analogous to features on the martian surface: yardangs carved in layered surficial deposits and in bedrock, invasive dune trains, wind-modified channels and interfluves, and depressions bounded by steep scarps. Like many of the topographic depresions on Mars, the Kharga Depression was invaded by crescentic dunes. In Egypt, stratigraphic relations between dunes, yardangs, mass-wasting debris, and wind-eroded flash-flood deposits record shifts in the relative effectiveness of wind, water, and mass-wasting processes as a function of climate change.

Microfacies analysis of foraminifera rich sedimentary rocks from the Desert Plateau, central Egypt.

NASA Astrophysics Data System (ADS)

Karnitschar, C.; Briguglio, A.; Hohenegger, J.

2012-04-01

Microfacies analysis on some samples from the Thebes Group have been carried on by means of thin sections. The study area is included in the Libyan Desert Plateau (central Egypt) at following coordinates N27° 36'30.58" E29° 44'58.34", near the biggest dune of Egypt, the Ghard Abu Muharik. Because of the round shape of the rocks and the desert patina on the surface they could easily be classified as the so called "Melonstones", which are located more southwards and mainly composed by stromatolites. On the contrary, the investigated samples show a completely different fauna and therefore have been separated from the "Melonstones". Even if shape and size are very similar and the desert patina covers all surfaces the same way the differences are impressive. To investigate the samples, two thin-sections have been prepared and analyzed at the microscope. The observed fauna is composed by: agglutinated benthic foraminifera (e.g., Dictyoconus egypticus), complex larger miliolids (e.g., Pseudolacazina cf. danatae, Fabularia sp.), alveolinids (Alveolina vredenburgi), green algae (Dasycladaceae), echinoids and corals. Because of the presence of symbionts bearing larger benthic foraminifera, which need light to feed photosymbionts, the rock was formed in a shallow water environment. With the abundant rock-building benthic foraminifera and calcareous algae the limestone shows a tendency to the packstone/wackestone facies. Based on the presence of Alveolina vredenburgi, the age of the samples can be estimate as lowermost Eocene belonging to the shallow benthic zone 5 (sensu Serra-Kiel et al., 1998). According the obtained data on stratigraphy and palaeoecology, a partial palaeoenvironmental reconstruction is possible for the Libyan Desert Plateau where outcrops are largely missing. Because of the round shape of the samples and the patina which covers them all around it can be assumed that they have been transported from longer distance. According to the geological map of the

Carrion insects of the Egyptian western desert.

PubMed

Hegazi, E M; Shaaban, M A; Sabry, E

1991-09-01

A general survey was made on the zoosaprophagous insects and their associates in a natural ecosystem in the Egyptian western desert (80 km west of Alexandria, 12 km from the Mediterranean Sea shore). Two types of traps were used, one for flying insects and the other for soil-burrowing insects. Two types of decaying media were used as baits: the common freshwater fish (Tilapia zilii Gerv.) and the desert snail (Eremina desertorum). More than 30 insect species were trapped. The following orders and families were represented: Diptera (Calliphoridae, Sarcophagidae, Muscidae); Coleoptera (Histeridae, Scarabaeidae, Dermestidae, Tenebrionidae); Hymenoptera (Chalcididae, Pteromalidae, Eulophidae, Formicidae). Monthly totals of numbers trapped in each of these groups are presented.

Cosmogenic, radiogenic, and stable isotopic constraints on groundwater residence time in the nubian aquifer, western desert of egypt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patterson, Leslie J.; Sturchio, Neil C.; Kennedy, B.Mack

2004-06-01

Measurements of radiochlorine ({sup 36}Cl), radiogenic noble gases ({sup 4}He and {sup 40}Ar), and stable chlorine isotope ratios were obtained to assess the residence time of groundwater in the Nubian Aquifer of the Western Desert of Egypt. Measured {sup 36}Cl/Cl ratios yield apparent residence times from {approx}0.2 to 1.2 x 10{sup 6} years in the deep (600-1200 m) groundwater (assuming constant Cl) and {le} 0.16 x 10{sup 6} years in the shallow (<600 m) groundwater. Values of {delta}{sup 37}Cl in the groundwater strengthen the application of the {sup 36}Cl dating method by constraining Cl sources and identifying groundwater mixing. Dissolvedmore » gases were measured in some of the deep groundwater samples. Measured {sup 4}He concentrations indicate accumulation of radiogenic {sup 4}He that is qualitatively consistent with the age progression indicated by the {sup 36}Cl/Cl ratios, but the flux of external {sup 4}He from the underlying crust has not been quantified and is not constant throughout the aquifer. Concentrations of {sup 40}Ar range from 3.3 to 6.7 x 10{sup -4} ccSTP/g and indicate excess air incorporation at recharge. Measured {sup 40}Ar/{sup 36}Ar ratios do not exceed the atmospheric ratio. A two-dimensional numerical hydrodynamic transect of the aquifer was modeled from the area of the Uweinat Uplift to the northern Bahariya Oasis. Predicted groundwater velocities in the deep portion of the aquifer are 0.5-3.5 m/yr with groundwater residence times up to 9 x 10{sup 5} years; residence times up to 1.3 x 10{sup 6} years are predicted in the confining shale. Aquifer properties are estimated by using the model to fit the measured {sup 36}Cl/Cl ratios. Under these conditions, hydrodynamic residence times are within about 30 percent of those calculated from {sup 36}Cl when mixing of Cl{sup -} is accounted for in the highest-Cl{sup -} deep groundwaters. By mutually calibrating multiple methods (hydrodynamic, {sup 36}Cl, and {sup 4}He), a consistent picture

Extensional collapse along the Sevier Desert reflection, northern Sevier Desert basin, western United States

NASA Astrophysics Data System (ADS)

Coogan, James C.; Decelles, Peter G.

1996-10-01

Newly released and previously published seismic reflection data from the northern Sevier Desert basin provide a complete seismic transect between the tilted western margin of the basin and the eastern breakaway zone. When tied to well and surface age data, the transect delineates a continuum of extensional fault and basin fill geometries that developed between late Oligocene and Pleistocene time across the basin. A minimum of 18 km of top-to-the-west normal displacement is estimated across the Sevier Desert from only the most conspicuous growth geometries and offsets across listric normal faults that sole downward into the Sevier Desert reflection (SDR). The SDR clearly marks a normal fault zone beneath the entire basin, where stratal truncations are imaged for 50% of the 39 km length of the reflection east of the Cricket Mountains block. Restoration of extensional displacement along this entire 39 km fault length is necessary to reconstruct the pre-Oligocene configuration and erosion level of Sevier thrust sheets across the Sevier Desert area. The SDR normal fault zone underlies the former topographic crest of the Sevier orogenic belt, where it accommodated extensional collapse after cessation of regional contractile tectonism.

Egypt and Red Sea

NASA Technical Reports Server (NTRS)

1982-01-01

A panaramic view of eastern Egypt, The Red Sea and Saudi Arabia beyond (24.0N, 33.0E). In this desert country, where water is life, the high Aswan Dam and the impounded waters of the Nile River in the foreground assure water availability into the next century. The Red Sea beyond, part of the Suez Canal seaway, serves as a commercial link to the world and separates Egypt from Saudi Arabia.

Integrating geologic and satellite imagery data for high-resolution mapping and gold exploration targets in the South Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

Zoheir, Basem; Emam, Ashraf

2012-05-01

The granitoid-greenstone belts of the Arabian-Nubian Shield are well-endowed with lode gold and massive sulfide ores. Although generally characterized by excellent outcrops and arid desert realm, poor accessibility and lack of finance have been always retardant to detailed geologic mapping of vast areas of the shield. Lack of comprehensive geological information and maps at appropriate scales would definitely hinder serious exploration programs. In this study, band ratioing, principal component analysis (PCA), false-color composition (FCC), and frequency filtering (FFT-RWT) of ASTER and ETM+ data have substantially improved visual interpretation for detailed mapping of the Gebel Egat area in South Eastern Desert of Egypt. By compiling field, petrographic and spectral data, controls on gold mineralization have been assessed in terms of association of gold lodes with particular lithological units and structures. Contacts between foliated island arc metavolcanics and ophiolites or diorite are likely to be favorable loci for auriferous quartz veins, especially where the NW-SE foliation is deflected into steeply dipping NNW-trending shear planes. High-resolution mapping of the greenstone belt, structures and alteration zones associated with gold lodes in the study area suggests that dilatation by foliation deflection was related to emplacement of the Egat granitic intrusion, attendant with a sinistral transpression regime (i.e., ˜640-550 Ma?). Gold mineralization associated with granitoid intrusions in transpression-induced pull-apart structures elsewhere in the Eastern Desert (e.g., Fawakhir, Sukari and Hangaliya mines) emphasize the reliability of this setting as a model for gold exploration targets in greenstone terrains of Egypt, and may be elsewhere in the Arabian-Nubian Shield.

Up-to-date Probabilistic Earthquake Hazard Maps for Egypt

NASA Astrophysics Data System (ADS)

Gaber, Hanan; El-Hadidy, Mahmoud; Badawy, Ahmed

2018-04-01

An up-to-date earthquake hazard analysis has been performed in Egypt using a probabilistic seismic hazard approach. Through the current study, we use a complete and homogenous earthquake catalog covering the time period between 2200 BC and 2015 AD. Three seismotectonic models representing the seismic activity in and around Egypt are used. A logic-tree framework is applied to allow for the epistemic uncertainty in the declustering parameters, minimum magnitude, seismotectonic setting and ground-motion prediction equations. The hazard analysis is performed for a grid of 0.5° × 0.5° in terms of types of rock site for the peak ground acceleration (PGA) and spectral acceleration at 0.2-, 0.5-, 1.0- and 2.0-s periods. The hazard is estimated for three return periods (72, 475 and 2475 years) corresponding to 50, 10 and 2% probability of exceedance in 50 years. The uniform hazard spectra for the cities of Cairo, Alexandria, Aswan and Nuwbia are constructed. The hazard maps show that the highest ground acceleration values are expected in the northeastern part of Egypt around the Gulf of Aqaba (PGA up to 0.4 g for return period 475 years) and in south Egypt around the city of Aswan (PGA up to 0.2 g for return period 475 years). The Western Desert of Egypt is characterized by the lowest level of hazard (PGA lower than 0.1 g for return period 475 years).

Structural interpretation of aeromagnetic data for the Wadi El Natrun area, northwestern desert, Egypt

NASA Astrophysics Data System (ADS)

Ibraheem, Ismael M.; Elawadi, Eslam A.; El-Qady, Gad M.

2018-03-01

The Wadi El Natrun area in Egypt is located west of the Nile Delta on both sides of the Cairo-Alexandria desert road, between 30°00‧ and 30°40‧N latitude, and 29°40‧ and 30°40‧E longitude. The name refers to the NW-SE trending depression located in the area and containing lakes that produce natron salt. In spite of the area is promising for oil and gas exploration as well as agricultural projects, Geophysical studies carried out in the area is limited to the regional seismic surveys accomplished by oil companies. This study presents the interpretation of the airborne magnetic data to map the structure architecture and depth to the basement of the study area. This interpretation was facilitated by applying different data enhancement and processing techniques. These techniques included filters (regional-residual separation), derivatives and depth estimation using spectral analysis and Euler deconvolution. The results were refined using 2-D forward modeling along three profiles. Based on the depth estimation techniques, the estimated depth to the basement surface, ranges from 2.25 km to 5.43 km while results of the two-dimensional forward modeling show that the depth of the basement surface ranges from 2.2 km to 4.8 km. The dominant tectonic trends in the study area at deep levels are NW (Suez Trend), NNW, NE, and ENE (Syrian Arc System trend). The older ENE trend, which dominates the northwestern desert is overprinted in the study area by relatively recent NW and NE trends, whereas the tectonic trends at shallow levels are NW, ENE, NNE (Aqaba Trend), and NE. The predominant structure trend for both deep and shallow structures is the NW trend. The results of this study can be used to better understand deep-seated basement structures and to support decisions with regard to the development of agriculture, industrial areas, as well as oil and gas exploration in northern Egypt.

Geomorphology and drift potential of major aeolian sand deposits in Egypt

NASA Astrophysics Data System (ADS)

Hereher, Mohamed E.

2018-03-01

Aeolian sand deposits cover a significant area of the Egyptian deserts. They are mostly found in the Western Desert and Northern Sinai. In order to understand the distribution, pattern and forms of sand dunes in these dune fields it is crucial to analyze the wind regimes throughout the sandy deserts of the country. Therefore, a set of wind data acquired from twelve meteorological stations were processed in order to determine the drift potential (DP), the resultant drift potential (RDP) and the resultant drift direction (RDD) of sand in each dune field. The study showed that the significant aeolian sand deposits occur in low-energy wind environments with the dominance of linear and transverse dunes. Regions of high-energy wind environments occur in the south of the country and exhibit evidence of deflation rather than accumulation with the occurrence of migratory crescentic dunes. Analysis of the sand drift potentials and their directions help us to interpret the formation of major sand seas in Egypt. The pattern of sand drift potential/direction suggests that the sands in these seas might be inherited from exogenous sources.

Kinematic analysis of the Migif area in the Eastern Desert of Egypt

NASA Astrophysics Data System (ADS)

Kassem, Osama M. K.

2014-11-01

The use of porphyroclasts rotating in a flowing matrix to estimate mean kinematic vorticity number (Wm) is important for quantifying the relative contributions of pure and simple shear in penetratively deformed rocks. The kinematic vorticity number determined for high temperature mylonitic gneisses in the Migif area in the Eastern Desert of Egypt range from ∼0.6 to 0.9. The results from vorticity and strain analyses indicate that deformation in the area deviated from simple shear. It is concluded that nappe stacking occurred early during the thrusting event, probably by brittle imbrications, and that ductile strain was superimposed on the nappe structure at high-pressure as shown by a penetrative subhorizontal foliation is developed subparallel to the tectonic contacts with the under- and overlying nappes. The accumulation of ductile strain during underplating was not by simple shear but involved a component of vertical shortening, which caused the subhorizontal foliation in the Migif area. In most cases, this foliation was formed during thrusting of the nappes onto each other, suggesting that nappe stacking was associated with vertical shortening.

Joint Egypt/United States report on Egypt/United States cooperative energy assessment. Volume 4 of 5 Vols. Annexes 6--10

DOE Office of Scientific and Technical Information (OSTI.GOV)

Purvis, Edward E.; Teagan, Peter; Little, Arthur D.

1979-04-01

Annex 6, which investigates the possible hydroelectric resources of Egypt, reveals that presently the only existing sites are on the upper Nile at the High and Aswan Dams. There are 8 sites on the Nile where it is practical to add hydroelectric generation and, of these, only 4 are feasible for immediate construction. There are also pumped-storage sites on the Nile and the Red Sea. There is also the Qattara Depression in the Western Desert which can be utilized for conventional, as well as pumped-storage generation, by bringing water from the Mediterranean Sea to the depression by canal or tunnel.more » The options were considered for construction of hydro plants to met the electric load growth of Egypt when other forms of energy supply would be integrated into a comprehensive supply pattern. In Annex 7, the prospective use of nuclear energy to meet Egypt's resources (uranium and thorium) to implement a nuclear energy program, and potential effects of the expanded use of nuclear energy are discussed. Annex 8 discusses solar energy (technology descriptions and impacts, solar thermal power, photovoltaics). Also wind power generation, biomass utilization, desalination, solar air conditioning and refrigeration, and cost of power from diesel engines are discussed. Annex 9 covers geothermal potentials in Egypt, discussing resources with temperatures above 180/sup 0/C; from 150 to 180/sup 0/C; from 100 to 150/sup 0/C; and with temperatures below 100/sup 0/C. Annex 10 discusses the electric power systems in Egypt. The following subjects are covered: existing electric power systems; electrical power facilities under construction or planned for construction by 1985; past and projected growth of electrical energy; distribution; and electrical power system projected from 1985 to 2000. (MCW)« less

Nile River, Lake Nasser, Aswan Dam, Egypt

NASA Image and Video Library

1991-08-11

Egypt's High Aswan Dam on the Nile River at the first cataracts, Nile River, (24.0N, 33.0E) was completed in 1971 to provide cheap hydroelectric power and to regulate the historically uneven flow of the Nile River. The contrast between the largely base rock desert east of the Nile versus the sand covered desert west of the river and the ancient irrigated floodplain downstream from the damsite is clearly shown.

Nile River, Lake Nasser, Aswan Dam, Egypt

NASA Technical Reports Server (NTRS)

1991-01-01

Egypt's High Aswan Dam on the Nile River at the first cataracts, Nile River, (24.0N, 33.0E) was completed in 1971 to provide cheap hydroelectric power and to regulate the historically uneven flow of the Nile River. The contrast between the largely base rock desert east of the Nile versus the sand covered desert west of the river and the ancient irrigated floodplain downstream from the damsite is clearly shown.

Sedimentary provenance of Maastrichtian oil shales, Central Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

Fathy, Douaa; Wagreich, Michael; Mohamed, Ramadan S.; Zaki, Rafat

2017-04-01

Maastrichtian oil shales are distributed within the Central Eastern Desert in Egypt. In this study elemental geochemical data have been applied to investigate the probable provenance of the sedimentary detrital material of the Maastrichtian oil shale beds within the Duwi and the Dakhla formations. The Maastrichtian oil shales are characterized by the enrichment in Ca, P, Mo, Ni, Zn, U, Cr and Sr versus post-Archean Australian shales (PAAS). The chondrite-normalized patterns of the Maastrichtian oil shale samples are showing LREE enrichment, HREE depletion, slightly negative Eu anomaly, no obvious Ce anomaly and typical shale-like PAAS-normalized patterns. The total REE well correlated with Si, Al, Fe, K and Ti, suggesting that the REE of the Maastrichtian oil shales are derived from terrigenous source. Chemical weathering indices such as Chemical Index of Alteration (CIA), Chemical Proxy of Alteration (CPA) and Plagioclase Index of Alteration (PIA) indicate moderate to strong chemical weathering. We suggest that the Maastrichtian oil shale is mainly derived from first cycle rocks especially intermediate rocks without any significant inputs from recycled or mature sources. The proposed data illustrated the impact of the parent material composition on evolution of oil shale chemistry. Furthermore, the paleo-tectonic setting of the detrital source rocks for the Maastrichtian oil shale is probably related to Proterozoic continental island arcs

Neoproterozoic Evolution and Najd‒Related Transpressive Shear Deformations Along Nugrus Shear Zone, South Eastern Desert, Egypt (Implications from Field‒Structural Data and AMS‒Technique)

NASA Astrophysics Data System (ADS)

Hagag, W.; Moustafa, R.; Hamimi, Z.

2018-01-01

The tectonometamorphic evolution of Nugrus Shear Zone (NSZ) in the south Eastern Desert of Egypt was reevaluated through an integrated study including field-structural work and magnetofabric analysis using Anisotropy of Magnetic Susceptibility (AMS) technique, complemented by detailed microstructural investigation. Several lines of evidence indicate that the Neoproterozoic juvenile crust within this high strain zone suffered an impressive tectonic event of left-lateral transpressional regime, transposed the majority of the earlier formed structures into a NNW to NW-directed wrench corridor depicts the northwestern extension of the Najd Shear System (NSS) along the Eastern Desert of Egypt. The core of the southern Hafafit dome underwent a high metamorphic event ( M 1) developed during the end of the main collisional orogeny in the Arabian-Nubian Shield (ANS). The subsequent M 2 metamorphic event was retrogressive and depicts the tectonic evolution and exhumation of the Nugrus-Hafafit area including the Hafafit gneissic domes, during the origination of the left-lateral transpressive wrench corridor of the NSS. The early tectonic fabric within the NSZ and associated highly deformed rocks was successfully detected by the integration of AMS-technique and microstructural observations. Such fabric grain was checked through a field-structural work. The outcomes of the present contribution advocate a complex tectonic evolution with successive and overlapped deformation events for the NSZ.

Science You Can Use Bulletin: Upwardly mobile in the western U.S. desert: Blackbrush shrublands respond to a changing climate

Treesearch

Sue Miller; Susan Meyer; Bryce Richardson; Rosemary Pendleton; Burton Pendleton; Stanley Kitchen

2013-01-01

Blackbrush (Colegyne ramosissima) is a desert shrubland species that is currently dominant on over three million acres of the transition zone between the cold desert of the Great Basin and the warm desert of the southwestern United States. Western landscapes are projected to experience unprecedented changes as the climate warms, and researchers at the Rocky Mountain...

Investigating a hydrothermal venting scenario at the Bahariya Oasis, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Lupi, Matteo; Mazzini, Adriano; Sciarra, Alessandra; Hammed, Mohammed S.; Schmindt, Susanne T.; Suessenberger, Annette

2017-04-01

The Bahariya depression (BD) (or Bahariya Oasis) is located in the Egyptian Western desert about 300 km SW of Cairo. The depression stretches for approximately 90 km along a NE-SW direction. The BD is known since Roman times for its thermal springs. Hot fluids were still emitted at the surface in the late 70ies before agricultural development caused the deepening of the groundwater table. Today, hot fluids are found at shallow depths and extracted for thermal bathing and farming. The oldest exposed rocks cropping out in the BD are of Early Cenomanian age and mainly consist of sandstones and claystones. Magmatic formations are also found in the BD and crop out as isolated basaltic formations. The most prominent tectonic feature dissecting the whole area is a NE-SW trending strike-slip fault system along which the depression developed. Satellite images reveal that large part of the BD area is characterised by concentric features (similar in shape to impact craters) that increase in number approaching the fault zone. A cross section of these features resembles to flattened crater-like structures (up to 10 m in height) with steeper external flanks and a gently dipping internal zone. Their average diameter is about 100 m. However, some of the largest features may reach nearly 400 m in diameter. We performed CO2 and CH4 soil gas flux measurements completing profiles across the structures finding a higher concentration of CO2 approaching the center. No significant CH4 flux variations were observed through the profiles. The central zone of one structure was targeted for detailed investigations. The samples recovered are characterised by the presence of halite-cemented breccias. XRD and semi-quantitative SEM analysis indicate the presence of mineral phases typical of hydrothermal circulation. In particular, some of the K-feldspars analyzed show a Ba-rich core with outer rims with no Ba content. One of the K-feldspar phases is sanidine and does not appear as an overgrowth

Clockwise rotation of the western Mojave Desert

NASA Technical Reports Server (NTRS)

Golombek, Matthew P.; Brown, Laurie L.

1988-01-01

A study of paleomagnetic data from Miocene volcanic rocks in the western Mojave Desert, which suggests about 25 deg of clockwise rotation, is presented. A total of 166 oriented core samples of two types of basalt were taken from 19 sites in the region. After demagnetization to 40 or 60 mT, application of structural corrections, and inversion of reversed sites, the data yielded an average direction of 51.6 deg inclination and 15.6 deg declination. When compared with the expected direction for Miocene rocks for stable North America, the direction for these Mojave rocks shows a clockwise rotation of 23.8 deg + or - 11.3 deg and a flattening of about 2.1 deg, a rotation which agrees in direction with oroclinal bending of the southern Sierra Nevada due to right-lateral shear along the western margin of North America. Most of this rotation is constrained by other paleomagnetic and strucural information to have occurred soon after the sampled basalts were deposited (about 20 Ma) and before about 16 Ma. These clockwise declination anomalies indicate that any subsequent counterclockwise rotation is small and/or compensated by previous clockwise rotation.

Cenozoic to Cretaceous paleomagnetic dataset from Egypt: New data, review and global analysis

NASA Astrophysics Data System (ADS)

Perrin, Mireille; Saleh, Ahmed

2018-04-01

Different phases of igneous activity took place in Egypt during the Mesozoic and the Cenozoic and oriented samples were collected from three Cenozoic localities (Baharya oasis in the Western Desert, Abu Had in the Eastern Desert and Quseir along the Red Sea coast), and four Cretaceous localities (Toshki & Abu Simbel south of Aswan, and Shalaten & Abu Shihat along the Red Sea coast). Rock magnetic properties of the samples indicate magnetite and titanomagnetite as the main carrier of the remanent magnetization. Following stepwise demagnetization, characteristic remanent directions were identified only for 62% of the samples, a fairly low rate for that type of samples, and 8 new paleomagnetic poles were calculated. All our Cenozoic poles fall clearly off Master Polar Wander Paths proposed for South Africa. Therefore, all paleomagnetic results, previously published for Egypt, were compiled from Cretaceous to Quaternary. The published poles largely overlap, blurring the Egyptian Apparent Polar Wander Path. A new analysis at the site level was then carried out. Only poles having a kappa larger than 50 were selected, and new pole positions were calculated by area and by epoch, when at least 3 sites were available. Even though the selection drastically reduced the number of considered poles, it allows definition of a reliable Cenozoic apparent polar wander trend for Egypt that differs from the South African Master Polar Wander Path by about 10-15 °. If the Cretaceous igneous poles are in good agreement with the rest of the African data, the sedimentary poles plot close to the Cenozoic portion of the South African Master Polar Wander Path, a discrepancy that could be related either to inclination flattening and/or error on age and/or remagnetization in the Cenozoic.

Assessment of groundwater potentiality using geophysical techniques in Wadi Allaqi basin, Eastern Desert, Egypt - Case study

NASA Astrophysics Data System (ADS)

Helaly, Ahmad Sobhy

2017-12-01

Electrical resistivity surveying has been carried out for the determination of the thickness and resistivity of layered media in Wadi Allaqi, Eastern Desert, Egypt. That is widely used geophysical tool for the purpose of assessing the groundwater potential and siting the best locations for boreholes in the unconfined Nubian Sandstone aquifers within the study area. This has been done using thirteen 1D Vertical Electrical Sounding (VES) surveys. 1D-VES surveys provide only layered model structures for the subsurface and do not provide comprehensive information for interpreting the structure and extent of subsurface hydro-geological features. The integration of two-dimensional (2D) geophysical techniques for groundwater prospecting has been done to provide a more detailed identification for the subsurface hydro-geological features from which potential sites for successful borehole locations are recognized. In addition, five magnetic profiles were measured for basement depth determination, expected geological structures and thickness of sedimentary succession that could include some basins suitable for groundwater accumulation as groundwater aquifers.

Petrogenesis of selected A-type granitic intrusions from Central Eastern Desert of Egypt

NASA Astrophysics Data System (ADS)

Hassan, Tharwat; Asran, Asran; Amron, Taha; Hauzenberger, Christoph

2014-05-01

The Pan-African orogeny in the Arabian-Nubian Shield was terminated by intrusion of A-type granites (~ 595 Ma; Greenberg, 1981) and its volcanic equivalents. Subsequent to the intrusions of these granitic bodies the shield was exhumed. Eroded A-type granite pebbles were found in the molasse sediments that were deposited in intermountain basins. Therefore the A-type granites provide information about the last stage of the Pan-African geochemical system. Preliminary whole-rock geochemical data of three granitic intrusions (Kadabora, Um Naggat and El shiekh Salem) from the Central Eastern Desert of Egypt; indicate that all of them are peraluminous and with A-type characteristics. These intrusions show low CaO content (average 0.43 %wt), high FeOT/MgO ratio (10.46-121.88), high Na2O+K2O (average 8.04 %wt), marked enrichment of high field strength elements (Y, Nb and Ga except Zr), depletion in MgO (0.01-0.11 %wt) and with low concentration of Sr and Ba. The studied granitoids were emplaced in within plate tectonic regime. References: Greenberg, J.K. (1981): Characteristic and origin of Egyptian younger granites. Bull. Geol. Soc. Am. Part 1, v.92: 224-232.

Substance geology of the western desert in Egypt and Sudan revealed by Shuttle Imaging Radar (SIR-A)

NASA Technical Reports Server (NTRS)

Breed, C. S.; Schaber, G. G.; Mccauley, J. F.; Grolier, M. J.; Haynes, C. V.; Elachi, C.; Blom, R.; Issawi, B.; Mchugh, W. P.

1983-01-01

A correlation of known archaeologic sites with the mapped locations of the streamcourses is expected and may lead to new interpretations of early human history in the Sahara. The valley networks, faults, and other subjacent bedrock features mapped on the SIR-A images are promising areas for ground water and mineral exploration. Additionally, the analogies between the interplay of wind and running water in the geologic history of the Sahara and of Mars are strengthened by the SIR-A discoveries of relict drainage systems beneath the eolian veneer of Egypt and Sudan.

Structural imaging of the East Beni Sueif Basin, north eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

Salem, E.; Sehim, A.

2017-12-01

The East Beni Sueif Basin is the only tested hydrocarbon-bearing basin on the eastern side of the Nile in Egypt. The basin is located around 150 km to the south of Cairo. This work introduces the first attempt of seismic interpretation and structural patterns of this basin, for which subsurface published works are lacking. Structural imaging of the area is achieved through interpretation of pre-stack time migration (PSTM) seismic cube and data sets of seven wells. The penetrated sedimentary section is represented by Albian-Middle Eocene sediments. The East Beni Sueif Basin is a type of the whole graben-system and is bounded by two NW-SE bounding faults. These faults had continued activity in an extensional regime associated with fault-propagating folds. The basin is traversed by a N75°E-trending fault system at basement level. This fault system separates the basin into two structural provinces. The Northwestern Province is deeper and shows more subsidence with a predominance of NW-trending longitudinal faults and N60·W oblique faults to the basin trend. The Southeastern Province is shallow and crossed by N14·W-trending faults which are slightly oblique to the basin axis. Albian time had witnessed the main extensional tectonic phase and resulted in major subsidence along basin-bounding faults associated with growth thickening of basal deposits. During Senonian time, the basin experienced a mild phase of transtensional tectonics, which formed negative-flower structures entrapping different folds along the N75°E and N60·W faults. The timing and style of these structures are similar to the Syrian-Arc structures in several Western Desert oil fields. The basin emerged during the Paleocene with scoured and eroded top Cretaceous sediments. Subsidence was resumed during the Early Eocene and resulted in 1500 m-thick carbonate sediments. Lastly, a mild extensional activity possibly occurred during the Oligocene-Miocene time. Despite the possible restricted potentiality

The Badain Jaran desert: remote sensing investigations.

USGS Publications Warehouse

Walker, A.S.; Olsen, J.W.; ,

1987-01-01

Approximately half the Badain Jaran desert in the north-western Alashan Plain of northern China is a sand sea. The remainder is gravel or bedrock. The north-western border of the desert is a playa. The desert has been imaged by both Landsat and the Shuttle Imaging Radar (SIR-A). -from Authors

Dust Plume off the Coast of Egypt

NASA Technical Reports Server (NTRS)

2007-01-01

Dwarfing the Nile, a river of dust flowed out of the deserts of northern Egypt on May 19, 2007. As the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra satellite passed overhead at 12:05 p.m. local time in Cairo, the sensor captured this image of the dust spreading northward over the Mediterranean Sea from the sandy deserts that span the country. At the margins of the plume, ribbons and ripples of dust are translucent, allowing a glimpse of the desert and water beneath, but in the center, the cloud is opaque, revealing nothing of the surface below. The part of north-central Egypt hidden by the dust plume is the Qattara Depression, the country's lowest point. Dipping down to 133 meters below sea level (436 feet), the depression is home to sandy deserts and dry lake beds that occasionally flood. The sand and fine, lake bed sediments are easily lofted into the air by strong winds that scour the area in late winter and early spring. In the eastern (right-hand) part of the image, the Nile River is lined by narrow ribbons of dull green vegetation. The fan-shaped delta is dotted with tan-colored spots, marking the location of cities and towns. The Nile Valley and Delta make up only a small fraction of the country's total land area, yet they support almost the entire population. The large image provided above has a spatial resolution (level of detail) of 250 meters per pixel. The MODIS Rapid Response Team provides this image in additional resolutions. The Earth Observatory also provides a 250-meter-resolution KMZ file of this image for use with Google Earth.

Sand-grain micromorphology used as a sediment-source indicator for Kharga Depression dunes (Western Desert, S Egypt)

NASA Astrophysics Data System (ADS)

Woronko, B.; Dłużewski, M.; Woronko, D.

2017-12-01

Roundness and surface-feature characteristics of sand grains collected from two dune ridges in Kharga Depression (southern Egypt) were tested for potential use as source-to-sink indicators of dunes movement. Grain examination was accommodated through Scanning Electron Microscope (SEM) analysis. Five grain types were distinguished: A) fresh; B) sheet precipitated with ;raindrop; structures; C) platy precipitated; D) broken; and E) with chemically etched surfaces-each type diagnostic of a specific geomorphic inheritance. Regarding the level of sphericity, these grains were subdivided into nine roundness classes (0.1-0.9), where angular grains are marked by 0.1 and very well-rounded grains by 0.9. Significant roundness and grain-type surface variations are observed both along dune ridges and between them. Poorly and medium-rounded grain populations dominate, along with sheet-precipitated grains. The contribution of well- and very well-rounded grains is low. The northern part of both eastern and western dune ridges is characterized by grains that represent high-energy aqueous environments with well-rounded grains, whereas platy precipitated grains with a lower level of roundness are concentrated in the middle part of the dune ridges. The southern part of the Kharga Depression is again characterized by sheet-precipitated grains. Our results indicate that the northern part of dune ridges in the Kharga Depression is mainly built of sands that originate from beyond the depression (e.g., Ghard Abu-Maharik) and the weathered deposits of the Nubian and Moghra Sandstones. The dunes in central and southern part of the Kharga Depression also derive sand from a local depression bottom comprised of playa and fluvial deposits. The growing importance of the local sand source may be explained by the lowering of the local groundwater table, which resulted in playa drying. This groundwater loss resulted in the degradation of the vegetation cover, facilitating an increase in wind

Solar Energy for Rural Egypt

NASA Astrophysics Data System (ADS)

Abdelsalam, Tarek I.; Darwish, Ziad; Hatem, Tarek M.

Egypt is currently experiencing the symptoms of an energy crisis, such as electricity outage and high deficit, due to increasing rates of fossil fuels consumption. Conversely, Egypt has a high solar availability of more than 18.5 MJ daily. Additionally, Egypt has large uninhabited deserts on both sides of the Nile valley and Sinai Peninsula, which both represent more than 96.5 % of the nation's total land area. Therefore, solar energy is one of the promising solutions for the energy shortage in Egypt. Furthermore, these vast lands are advantageous for commissioning large-scaled solar power projects, not only in terms of space availability, but also of availability of high quality silicon (sand) required for manufacturing silicon wafers used in photovoltaic (PV) modules. Also, rural Egypt is considered market a gap for investors, due to low local competition, and numerous remote areas that are not connected to the national electricity grid. Nevertheless, there are some obstacles that hinder the progress of solar energy in Egypt; for instance, the lack of local manufacturing capabilities, security, and turbulent market in addition to other challenges. This paper exhibits an experience of the authors designing and installing decentralized PV solar systems, with a total rated power of about 11 kW, installed at two rural villages in at the suburbs of Fayoum city, in addition to a conceptual design of a utility scale, 2 MW, PV power plant to be installed in Kuraymat. The outcomes of this experience asserted that solar PV systems can be a more technically and economically feasible solution for the energy problem in rural villages.

Prevalence of injuries among high school students in Eastern and Western parts of Cairo, Egypt.

PubMed

Wahdan, Maha M; Sayed, Amany M; Abd Elaziz, Khaled M; El-Hoseiny, Mostafa M; Al-Gwaily, Mohamed M

2016-12-01

Injury is the leading cause of death and long term disability and a significant contributor to healthcare costs among children worldwide especially those aged 15-19 years. To determine the prevalence of injuries among secondary school students in Cairo, Egypt and to explore the associated risk factors for sustaining injury. A Cross-sectional study was conducted on secondary school students in eastern and western part of Cairo; self-administered questionnaire was used for assessing injuries sustained in previous 12 months and the associated risk factors for injury. The overall prevalence of injuries was 68.5%. Unintentional injuries were the most common injuries falls (50%) and burns (38.6%). Significant factors associated with sustaining injury were truancy, smoking, alcohol use, quarreling behavior, carrying weapon, threatened by weapon and verbal bullying. This study showed a high prevalence of injuries among high school students in Egypt which necessitates raising public awareness about the magnitude and burden of injuries among adolescents. Copyright © 2016 Elsevier Ltd. All rights reserved.

Bi-Static Deep Electromagnetic Soundings for Martian Subsurface Characterization: Experimental Validation in the Egyptian Western Desert

NASA Astrophysics Data System (ADS)

Ciarletti, V.; Le Gall, A.; Berthelier, J. J.; Corbel, Ch.; Dolon, F.; Ney, R.; Reineix, A.; Guiffaud, Ch.; Clifford, S.; Heggy, E.

2007-03-01

A bi-static version of the HF GPR TAPIR developed for martian deep soundings has been operated in the Egyptian Western Desert. The study presented focuses on the retrieval of the direction of arrival of the observed echoes on both simulated and measured d

The thickness of cover sequences in the Western Desert of Iraq from a power spectrum analysis of gravity and magnetic data

NASA Astrophysics Data System (ADS)

Mousa, Ahmed; Mickus, Kevin; Al-Rahim, Ali

2017-05-01

The Western Desert of Iraq is part of the stable shelf region on the Arabian Plate where the subsurface structural makeup is relatively unknown due to the lack of cropping out rocks, deep drill holes and deep seismic refraction and reflection profiles. To remedy this situation, magnetic and gravity data were analyzed to determine the thickness of the Phanerozoic cover sequences. The 2-D power spectrum method was used to estimate the depth to density and magnetic susceptibility interfaces by using 0.5° square windows. Additionally, the gravity data were analyzed using isostatic residual and decompensative methods to isolate gravity anomalies due to upper crustal density sources. The decompensative gravity anomaly and the differentially reduced to the pole magnetic map indicate a series of mainly north-south and northwest-southeast trending maxima and minima anomalies related to Proterozoic basement lithologies and the varying thickness of cover sequences. The magnetic and gravity derived thickness of cover sequences maps indicate that these thicknesses range from 4.5 to 11.5 km. Both maps in general are in agreement but more detail in the cover thicknesses was determined by the gravity analysis. The gravity-based cover thickness maps indicates regions with shallower depths than the magnetic-based cover thickness t map which may be due to density differences between limestone and shale units within the Paleozoic sediments. The final thickness maps indicate that the Western Desert is a complicated region of basins and uplifts that are more complex than have been shown on previous structural maps of the Western Desert. These basins and uplifts may be related to Paleozoic compressional tectonic events and possibly to the opening of the Tethys Ocean. In addition, petroleum exploration could be extended to three basins outlined by our analysis within the relatively unexplored western portions of the Western Desert.

Greenstone-hosted lode-gold mineralization at Dungash mine, Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

Zoheir, Basem; Weihed, Pär

2014-11-01

The auriferous quartz ± carbonate veins at Dungash mine, central Eastern Desert of Egypt, are confined to ∼E-trending dilation zones within variably foliated/sheared metavolcanic/volcaniclastic rocks. The vein morphology and internal structures demonstrate formation concurrent with a dextral shear system. The latter is attributed to flexural displacement of folded, heterogeneous rock blocks through transpression increment, late in the Neoproterozoic deformation history of the area. Geochemistry of the host metavolcanic/metavolcaniclastic rocks from the mine area suggests derivation from a low-K, calc-alkaline magma in a subduction-related, volcanic arc setting. In addition, chemistry of disseminated Cr-spinels further constrain on the back-arc basin setting and low-grade metamorphism, typical of gold-hosting greenstone belts elsewhere. Mineralogy of the mineralized veins includes an early assemblage of arsenopyrite-As-pyrite-gersdorffite ± pyrrhotite, a transitional pyrite-Sb-arsenopyrite ± gersdorffite assemblage, and a late tetrahedrite-chalcopyrite-sphalerite-galena-gold assemblage. Based on arsenopyrite and chlorite geothermometers, formation of gold-sulfide mineralization occurred between ∼365 and 280 °C. LA-ICP-MS measurements indicate the presence of refractory Au in arsenian pyrite (up to 53 ppm) and Sb-bearing arsenopyrite (up to 974 ppm). Abundant free-milling gold associated with the late sulfide assemblage may have been mobilized and re-distributed by circulating, lower temperature ore fluids in the waning stages of the hydrothermal system. Based on the isotopic values of vein quartz and carbonate, the calculated average δ18OH2O values of the ore fluids are 5.0 ± 1.4‰ SMOW for quartz, and 3.3 ± 1.4‰ for vein carbonate. The measured carbonate δ13C values correspond to ore fluids with δ13CCO2 = -6.7 ± 0.7‰ PDB. These results suggest a mainly metamorphic source for ore fluids, in good agreement with the vein morphology, textures and

Q fever in Egypt: Epidemiological survey of Coxiella burnetii specific antibodies in cattle, buffaloes, sheep, goats and camels.

PubMed

Klemmer, Jessica; Njeru, John; Emam, Aya; El-Sayed, Ahmed; Moawad, Amira A; Henning, Klaus; Elbeskawy, Mohamed A; Sauter-Louis, Carola; Straubinger, Reinhard K; Neubauer, Heinrich; El-Diasty, Mohamed M

2018-01-01

Q fever is a zoonotic disease caused by the bacterium Coxiella burnetii. Clinical presentation in humans varies from asymptomatic to flu-like illness and severe sequelae may be seen. Ruminants are often sub-clinically infected or show reproductive disorders such as abortions. In Egypt, only limited data on the epidemiology of Q fever in animals are available. Using a stratified two stage random sampling approach, we evaluated the prevalence of Coxiella burnetii specific antibodies among ruminants and camels in 299 herds. A total of 2,699 blood samples was investigated using enzyme-linked-immunosorbent assay (ELISA). Coxiella burnetii specific antibodies were detected in 40.7% of camels (215/528), 19.3% of cattle (162/840), 11.2% of buffaloes (34/304), 8.9% of sheep (64/716) and 6.8% of goats (21/311), respectively. Odds of seropositivity were significantly higher for cattle (aOR: 3.17; 95% CI: 1.96-5.13) and camels (aOR: 9.75; 95% CI: 6.02-15.78). Significant differences in seropositivity were also found between domains (Western Desert, Eastern Desert and Nile Valley and Delta) and 25 governorates (p < 0.001), respectively. Animal rearing in the Eastern Desert domain was found to be a significant risk factor (aOR: 2.16; 95% CI: 1.62-2.88). Most seropositive animals were older than four years. No correlation between positive titers and husbandry practices or animal origin were found (p > 0.05). Only 8.7% of the interviewed people living on the farms consumed raw camel milk and none reported prior knowledge on Q fever. Findings from this nationwide study show that exposure to Coxiella burnetii is common in ruminants and camels. Disease awareness among physicians, veterinarians and animal owners has to be raised. Future epidemiological investigations have to elucidate the impact of Q fever on human health and on the economy of Egypt.

Natural radionuclide concentrations in granite rocks in Aswan and Central-Southern Eastern Desert, Egypt and their radiological implications.

PubMed

Issa, Shams A M; Uosif, M A M; Abd el-Salam, L M

2012-07-01

Different types of granites, used extensively in local construction, were collected from five localities in Egypt, namely: Abu Ziran (Central Eastern Desert), Gabal El Maesala (Aswan) and three areas from Wadi Allaqi, (Gabal Abu Marw, Gabal Haumor and Gabal um Shalman), in the South Eastern Desert. Granite samples were studied radiologically, petrographically and geochemically. The contents of natural radionuclides ((226)Ra, (232)Th and (40)K) were measured in investigated samples by using gamma spectrometry [NaI (Tl) 3'×3']. The activity concentrations of (226)Ra, (232)Th and (40)K in the selected granite samples ranged from 9±0.5 to 111±7, 8±1 to 75±4 and 100±6 to 790±40 Bq kg(-1), respectively. The external hazard index (H(ex)), absorbed dose and annual effective dose rate were evaluated to assess the radiation hazard for people living in dwellings made of the materials studied. The calculated radium equivalents were lower than the values recommended for construction materials (370 Bq kg(-1)). The excess lifetime cancer risks were also calculated. Petrographically, the granites studied are varied in the form of potash-feldspar, quartz, plagioclase, mica and hornblende. The accessory minerals are zircon, apatite and allanite. Geochemically, the chemical composition of the granite is studied especially for major oxides. They are characterized to have SiO(2), K(2)O, Na(2)O and Al(2)O(3) with depletion in CaO, MgO, TiO(2) and P(2)O(5).

Megaliths and Neolithic astronomy in southern Egypt

NASA Astrophysics Data System (ADS)

Malville, J. Mckim; Wendorf, Fred; Mazar, Ali A.; Schild, Romauld

1998-04-01

The Sahara west of the Nile in southern Egypt was hyperarid and unoccupied during most of the Late Pleistocene epoch. About 11,000 years ago the summer monsoons of central Africa moved into Egypt, and temporary lakes or playas were formed. The Nabta Playa depression, which is one of the largest in southern Egypt, is a kidney-shaped basin of roughly 10km by 7km in area. We report the discovery of megalithic alignments and stone circles next to locations of Middle and Late Neolithic communities at Nabta, which suggest the early development of a complex society. The southward shift of the monsoons in the Late Neolithic age rendered the area once again hyperarid and uninhabitable some 4,800 radiocarbon years before the present (years BP). This well-determined date establishes that the ceremonial complex of Nabta, which has alignments to cardinal and solstitial directions, was a very early megalithic expression of ideology and astronomy. Five megalithic alignments within the playa deposits radiate outwards from megalithic structures, which may have been funerary structures. The organization of the megaliths suggests a symbolic geometry that integrated death, water, and the Sun. An exodus from the Nubian Desert at ~4,800 years BP may have stimulated social differentiation and cultural complexity in predynastic Upper Egypt.

Lake Nasser and Toshka Lakes, Egypt

NASA Technical Reports Server (NTRS)

2002-01-01

Lake Nasser (center) and the Toshka Lakes (center left) glow emerald green and black in this MODIS true-color image acquired March 8, 2002. Located on and near the border of Egypt and Norther Sudan, these lakes are an oasis of water in between the Nubian (lower right) and Libyan Deserts (upper left). Also visible are the Red Sea (in the upper right) and the Nile River (running north from Lake Nasser). Credit: Jacques Descloitres, MODIS Land Rapid Response Team, NASA/GSFC

Resilience to disturbance and resistance to alien grass invasions in the cold desert of western North America

USDA-ARS?s Scientific Manuscript database

Alien grass invasions are resulting in ecosystem-level transformations of entire landscapes in arid and semi-arid ecosystems. The cold desert of western US is undergoing such a transformation, and is considered one of the most imperiled large ecosystems in the US. To address the rapid and complex ch...

Uranium migration and favourable sites of potential radioelement concentrations in Gabal Umm Hammad area, Central Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

Youssef, Mohamed A. S.; Sabra, Mohamed Elsadek M.; Abdeldayem, Abdelaziz L.; Masoud, Alaa A.; Mansour, Salah A.

2017-12-01

Airborne gamma-ray spectrometric data, covering Gabal Umm Hammad area, near Quseir City, in the Eastern Desert of Egypt, has been utilized to identify the uranium migration path, and U, Th and K-favorability indices. The following of the uranium migration technique enabled estimation of the amount of migrated uranium, in and out of the rock units. Investigation of the Taref Formation, Nakhil Formation, Tarawan Formation and Dawi Formation shows large negative amount of uranium migration, indicating that uranium leaching is outward from the geologic body toward surrounding rock units. Moreover, calculation of the U, Th and K-favorability indices has been carried out for the various rock units to locate the rocks having the highest radioelement potentialities. The rock units that possess relatively major probability of uranium potentiality include Mu‧tiq Group, weakly deformed granitic rocks, and Trachyte plugs and sheets. Meanwhile, the rock units with major potential of Th-index are Taref Formation, Quseir Formation and Dawi Formation. The rock units with major potential of K-index are Dokhan volcanic and Mu‧tiq group.

Basin deconstruction-construction: Seeking thermal-tectonic consistency through the integration of geochemical thermal indicators and seismic fault mechanical stratigraphy ​- Example from Faras Field, North Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Pigott, John D.; Abouelresh, Mohamed O.

2016-02-01

To construct a model of a sedimentary basin's thermal tectonic history is first to deconstruct it: taking apart its geological elements, searching for its initial conditions, and then to reassemble the elements in the temporal order that the basin is assumed to have evolved. Two inherent difficulties implicit to the analysis are that most organic thermal indicators are cumulative, irreversible and a function of both temperature and time and the non-uniqueness of crustal strain histories which complicates tectonic interpretations. If the initial conditions (e.g. starting maturity of the reactants and initial crustal temperature) can be specified and the boundary conditions incrementally designated from changes in the lithospheric heat engine owing to stratigraphic structural constraints, then the number of pathways for the temporal evolution of a basin is greatly reduced. For this investigation, model input uncertainties are reduced through seeking a solution that iteratively integrates the geologically constrained tectonic subsidence, geochemically constrained thermal indicators, and geophysically constrained fault mechanical stratigraphy. The Faras oilfield in the Abu Gharadig Basin, North Western Desert, Egypt, provides an investigative example of such a basin's deconstructive procedure. Multiple episodes of crustal extension and shortening are apparent in the tectonic subsidence analyses which are constrained from the fault mechanical stratigraphy interpreted from reflection seismic profiles. The model was iterated with different thermal boundary conditions until outputs best fit the geochemical observations. In so doing, the thermal iterations demonstrate that general relationship that basin heat flow increases decrease vertical model maturity gradients, increases in surface temperatures shift vertical maturity gradients linearly to higher values, increases in sediment conductivities lower vertical maturities with depth, and the addition of ;ghost; layers

Geothermal resources of the western arm of the Black Rock Desert, northwestern Nevada; Part I, geology and geophysics

USGS Publications Warehouse

Schaefer, Donald H.; Welch, Alan H.; Mauzer, Douglas K.

1983-01-01

Studies of the geothermal potential of the western arm of the Black Rock Desert in northwestern Nevada included a compilation of existing geologic data on a detailed map, a temperature survey at 1-meter depth, a thermal-scanner survey, and gravity and seismic surveys to determine basin geometry. The temperature survey showed the effects of heating at shallow depths due to rising geothermal fluids near the known hot spring areas. Lower temperatures were noted in areas of probable near-surface ground-water movement. The thermal-scanner survey verified the known geothermal areas and showed relatively high-temperature areas of standing water and ground-water discharge. The upland areas of the desert were found to be distinctly warmer than the playa area, probably due to low thermal diffusivity resulting from low moisture content. The surface geophysical surveys indicated that the maximum thickness of valley-fill deposits in the desert is about 3,200 meters. Gravity data further showed that changes in the trend of the desert axis occurred near thermal areas. (USGS)

Larger benthic foraminiferal turnover across the Eocene-Oligocene transition at Siwa Oasis, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Orabi, H.; El Beshtawy, M.; Osman, R.; Gadallah, M.

2015-05-01

In the Eocene part of the Siwa Oasis, the larger foraminifera are represented by the genera Nummulites, Arxina, Operculina, Sphaerogypsina, Asterocyclina, Grzybowskia, Silvestriella, Gaziryina and Discocyclina in order of abundance. Operculina continues up to the early Oligocene as modern representatives in tropical regions, while the other genera became extinct. Nevertheless, the most common larger foraminiferal genus Lepidocyclina (Nephrolepidina) appears only in the lowermost Oligocene. In spite of the Eocene-Oligocene (E/O) transition is thought to have been attended by major continental cooling at northern middle and high latitudes, we discover that at the Siwa Oasis, there is a clear warming trend from the late Eocene (extinction level of Nummulites, Sphaerogypsina, Asterocyclina, Grzybowskia, Silvestriella and Discocyclina) to the early Oligocene is observed due to the high abundance of Operculina and occurrence of kaolinite and gypsiferous shale deposits in both Qatrani and El Qara formations (Oligocene) at this transition. The El Qara Formation is a new rock unit proposed herein for the Oligocene (Rupelian age) in the first time. Several episodes of volcanic activity occurred in Egypt during the Cenozoic. Mid Tertiary volcanicity was widespread and a number of successive volcanic pulses are starting in the late Eocene. The release of mantle CO2 from this very active volcanic episode may have in fact directly caused the warm Eocene-Oligocene greenhouse climate effect.

Tectonic framework of northeast Egypt and its bearing on hydrocarbon exploration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khalil, M.; Moustafa, A.R.

1995-08-01

Detailed structural study of northern and central Sinai, the northern Eastern Desert, and the northern Gulf of Suez clarified the tectonic framework of northeast Egypt. This framework is related to the movements between the African Plate and the Eurasian and Arabian Plates. Late Cretaceous folding and thrusting in response to oblique convergence between the African and Eurasian Plates formed NE-ENE oriented, doubly plunging, en echelon folds of the northern Egypt fold belt. This fold belt is well exposed in northern Sinai and a few other places but is concealed under younger sediments in the other parts of northern Egypt. Youngermore » folding of local importance is related to dextral slip on the Themed Fault (Central Sinai) in post Middle Eocene-pre Miocene time. Early Miocene rifting of the Afro-Arabian Plate led to the opening of the Suez rift and deposition of significant syn-rift facies. Half grabens and tilted fault blocks dominate the rift. Slightly tilted fault blocks characterize the competent Middle Eocene limestones of the Eastern Desert south of the Cairo-Suez road but north of this road, Middle Eocene rocks are locally dragged on nearby E-W and NW-SE oriented faults forming fault-drag folds. Ductile Upper Eocene and Miocene rocks are also folded about gentle NW-SE oriented doubly plunging folds. The different stages of tectonic activity in northern Egypt contributed to the development of different types of structural traps as well as different source, reservoir, and cap rocks. The sedimentary history of the region indicates well developed marine sediments of Jurassic, Cretaceous, Eocene, and Miocene ages. Basin development in structurally low areas provided good sites for hydrocarbon generation and maturation.« less

Chihuahuan Deserts Ecoregion: Chapter 27 in Status and trends of land change in the Western United States--1973 to 2000

USGS Publications Warehouse

Ruhlman, Jana; Gass, Leila; Middleton, Barry

2012-01-01

The Chihuahuan Desert is the largest of the North American deserts, extending from southern New Mexico and Texas deep into Mexico, with approximately 90 percent of its area falling south of the United States–Mexico border (Lowe, 1964, p. 24). The Chihuahuan Deserts Ecoregion covers approximately 174,472 km2 (67,364 mi2) within the United States, including much of west Texas, southern New Mexico, and a small portion of southeastern Arizona (Omernik, 1987; U.S. Environmental Protection Agency, 1997). The ecoregion is generally oriented from northwest to southeast, with the Madrean Archipelago Ecoregion to the west; the Arizona/New Mexico Mountains, Arizona/New Mexico Plateau, Southwestern Tablelands, and Western High Plains Ecoregions to the north; and the Edwards Plateau and Southern Texas Plains Ecoregions to the east (fig. 1).

Q fever in Egypt: Epidemiological survey of Coxiella burnetii specific antibodies in cattle, buffaloes, sheep, goats and camels

PubMed Central

Njeru, John; Emam, Aya; El-Sayed, Ahmed; Moawad, Amira A.; Henning, Klaus; Elbeskawy, Mohamed A.; Sauter-Louis, Carola; Straubinger, Reinhard K.; Neubauer, Heinrich; El-Diasty, Mohamed M.

2018-01-01

Q fever is a zoonotic disease caused by the bacterium Coxiella burnetii. Clinical presentation in humans varies from asymptomatic to flu-like illness and severe sequelae may be seen. Ruminants are often sub-clinically infected or show reproductive disorders such as abortions. In Egypt, only limited data on the epidemiology of Q fever in animals are available. Using a stratified two stage random sampling approach, we evaluated the prevalence of Coxiella burnetii specific antibodies among ruminants and camels in 299 herds. A total of 2,699 blood samples was investigated using enzyme-linked-immunosorbent assay (ELISA). Coxiella burnetii specific antibodies were detected in 40.7% of camels (215/528), 19.3% of cattle (162/840), 11.2% of buffaloes (34/304), 8.9% of sheep (64/716) and 6.8% of goats (21/311), respectively. Odds of seropositivity were significantly higher for cattle (aOR: 3.17; 95% CI: 1.96–5.13) and camels (aOR: 9.75; 95% CI: 6.02–15.78). Significant differences in seropositivity were also found between domains (Western Desert, Eastern Desert and Nile Valley and Delta) and 25 governorates (p < 0.001), respectively. Animal rearing in the Eastern Desert domain was found to be a significant risk factor (aOR: 2.16; 95% CI: 1.62-2.88). Most seropositive animals were older than four years. No correlation between positive titers and husbandry practices or animal origin were found (p > 0.05). Only 8.7% of the interviewed people living on the farms consumed raw camel milk and none reported prior knowledge on Q fever. Findings from this nationwide study show that exposure to Coxiella burnetii is common in ruminants and camels. Disease awareness among physicians, veterinarians and animal owners has to be raised. Future epidemiological investigations have to elucidate the impact of Q fever on human health and on the economy of Egypt. PMID:29466380

Mineral chemistry and geochemistry of ophiolitic metaultramafics from Um Halham and Fawakhir, Central Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

Abdel-Karim, Abdel-Aal M.; Ali, Shehata; El-Shafei, Shaimaa A.

2018-03-01

This study is focused on ophiolitic metaultramafics from Um Halham and Fawakhir, Central Eastern Desert of Egypt. The rocks include serpentinized peridotites, serpentinites together with talc- and quartz-carbonates. The primary spinel relict is Al-chromite [Cr# > 60], which is replaced by Cr-magnetite during metamorphism. The high Cr# of Al-chromites resembles supra-subduction zone (SSZ) peridotites and suggests derivation from the deeper portion of the mantle section with boninitic affinity. These mantle rocks equilibrated with boninitic melt have been generated by high melting degrees. The estimated melting degrees ( 19-24%) lie within the range of SSZ peridotites. The high Cr# of spinel and Fo content of olivine together with the narrow compositional range suggest a mantle residual origin. Serpentinized peridotite and serpentinites have low Al2O3/SiO2 ratios (mostly < 0.03) like fore-arc mantle wedge serpentinites and further indicate that their mantle protolith had experienced partial melting before serpentinization process. Moreover, they have very low Nb, Ta, Zr and Hf concentrations along with sub-chondritic Nb/Ta (0.3-16) and Zr/Hf (mostly 1-20) ratios further confirming that their mantle source was depleted by earlier melting extraction event. The high chondrite normalized (La/Sm)N ratios (average 10) reflect input of subduction-related slab melts/fluids into their mantle source.

Novel green algal isolates from the Egyptian hyper-arid desert oases: a polyphasic approach with a description of Pharao desertorum gen. et sp. nov. (Chlorophyceae, Chlorophyta).

PubMed

Saber, Abdullah A; Fučíková, Karolina; McManus, Hilary A; Guella, Graziano; Cantonati, Marco

2018-03-30

The biodiversity of terrestrial algae is still grossly understudied, and African deserts in particular are barely touched in this respect. Here, four coccoid green algae from oases in the Western Desert of Egypt were characterized using a combination of morphotaxonomic, ecological and 18S rDNA data, with additional carotenoid and lipid analyses for two of the strains. Three strains were identified as affiliated with known taxa: Mychonastes sp., Asterarcys sp. (first report of this genus from a desert soil), and Stichococcus cf. deasonii. The fourth strain is proposed to represent a new cryptic genus Pharao gen. nov., with the type species P. desertorum sp. nov. The new taxon is sister to the clade of uncharacterized North American desert strains of Radiococcaceae (Chlorophyceae, Chlorophyta). The pigment profile of P. desertorum gen. et sp. nov. revealed carotenoids and chlorophylls typical of green algae. Bioorganic analysis showed a complex lipidome based on phospho- (PC), galacto- (MGDG and DGDG), betaine- (DGTS), and sulfoquinovosyl- (SQDG) membrane lipids, besides significant amounts of storage neutral lipids such as diacyl- (DAG) and triacylglycerols (TAG). The presence of saturated alkyl chains within all the membrane lipid classes in P. desertorum and Asterarcys sp. appears to reflect the need to maintain membrane fluidity and viscosity. In summary, African deserts likely still harbor new taxa to be described, and lipidomic analyses of such taxa may provide clues about their ability to survive in the extremely harsh desert habitats. © 2018 Phycological Society of America.

Earth observation taken by the Expedition 43 crew

NASA Image and Video Library

2015-05-08

ISS043E182401 (05/08/2015) --- A large portion of northern Africa is covered in desert sand as this image from the International Space Station by NASA astronaut Scott Kelly demonstrates. This nearly waterless area is located in the Great Sand Sea of the Libyan Desert and part of western Egypt.

Effects of protective fencing on birds, lizards, and black-tailed hares in the Western Mojave Desert

USGS Publications Warehouse

Brooks, M.

1999-01-01

Effects of protective fencing on birds, lizards, black-tailed hares (Lepus californicus), perennial plant cover, and structural diversity of perennial plants were evaluated from spring 1994 through winter 1995 at the Desert Tortoise Research Natural Area (DTNA), in the Mojave Desert, California. Abundance and species richness of birds were higher inside than outside the DTNA, and effects were larger during breeding than wintering seasons and during a high than a low rainfall year. Ash-throated flycatchers (Myiarchus cinerascens), cactus wrens (Campylorhynchus brunneicapillus), LeConte's thrashers (Toxostoma lecontei), loggerhead shrikes (Lanius ludovicianus), sage sparrows (Amphispiza belli), and verdins (Auriparus flaviceps) were more abundant inside than outside the DTNA. Nesting activity was also more frequent inside. Total abundance and species richness of lizards and individual abundances of western whiptail lizards (Cnemidophorous tigris) and desert spiny lizards (Sceloporus magister) were higher inside than outside. In contrast, abundance of black-tailed hares was lower inside. Structural diversity of the perennial plant community did not differ due to protection, but cover was 50% higher in protected areas. Black-tailed hares generally prefer areas of low perennial plant cover, which may explain why they were more abundant outside than inside the DTNA. Habitat structure may not affect bird and lizard communities as much as availability of food at this desert site, and the greater abundance and species richness of vertebrates inside than outside the DTNA may correlate with abundances of seeds and invertebrate prey.

Desert Test Site Uniformity Analysis

NASA Technical Reports Server (NTRS)

Kerola, Dana X.; Bruegge, Carol J.

2009-01-01

Desert test sites such as Railroad Valley (RRV) Nevada, Egypt-1, and Libya-4 are commonly targeted to assess the on-orbit radiometric performance of sensors. Railroad Valley is used for vicarious calibration experiments, where a field-team makes ground measurements to produce accurate estimates of top-of-atmosphere (TOA) radiances. The Sahara desert test sites are not instrumented, but provide a stable target that can be used for sensor cross-comparisons, or for stability monitoring of a single sensor. These sites are of interest to NASA's Atmospheric Carbon Observation from Space (ACOS) and JAXA's Greenhouse Gas Observation SATellite (GOSAT) programs. This study assesses the utility of these three test sites to the ACOS and GOSAT calibration teams. To simulate errors in sensor-measured radiance with pointing errors, simulated data have been created using MODIS Aqua data. MODIS data are further utilized to validate the campaign data acquired from June 22 through July 5, 2009. The first GOSAT vicarious calibration experiment was conducted during this timeframe.

Red Sea rift-related Quseir basalts, central Eastern Desert, Egypt: Petrogenesis and tectonic processes

NASA Astrophysics Data System (ADS)

Farahat, Esam S.; Ali, Shehata; Hauzenberger, Christoph

2017-01-01

Mineral and whole-rock chemistry of Red Sea rift-related Tertiary basalts from south Quseir city, central Eastern Desert of Egypt is presented to investigate their petrogenesis and relationship to tectonic processes. The south Quseir basalts (SQB) are classified as high-Ti (TiO2 >2 wt.%) subalkaline transitional lava emplaced in an anorogenic tectonic setting. Their Mg# varies from 48 to 53 indicating the evolved nature of the SQB. Pearce element ratios suggest that the SQB magmas evolved via fractional crystallization of olivine + clinopyroxene ± plagioclase, but the absence of Eu anomalies argues against significant plagioclase fractionation. Clinopyroxene compositions provide evidence for polybaric fractionation of the parental mafic magmas. Estimated temperatures of crystallization are 1015 to 1207 °C for clinopyroxene and 1076 to 1155 °C for plagioclase. These values are interpreted to result from early stage crystallization of clinopyroxene followed by concurrent crystallization of clinopyroxene and plagioclase. The incompatible trace element signatures of the SQB (La/Ba = 0.08-0.10 and La/Nb = 0.89-1.04) are comparable to those of ocean island basalts (OIB) generated from an asthenospheric mantle source unaffected by subduction components. Modeling calculations indicate that the SQB primary magmas were derived from 4-5% partial melting of a garnet-bearing lherzolite mantle source. The NE Egyptian basaltic volcanism is spatially and temporally related to Red Sea rifting and to the local E-W striking faults, confirming a relationship to tectonic activity. Our results suggest that the extensional regime associated with Red Sea rifting controlled the generation of the Egyptian basalts, likely as a result of passive upwelling of asthenospheric mantle.

Oppositely dipping thrusts and transpressional imbricate zone in the Central Eastern Desert of Egypt

NASA Astrophysics Data System (ADS)

Abd El-Wahed, Mohamed A.

2014-12-01

This paper documents the 40-60 km wide ENE-WSW trending Mubarak-Barramiya shear belt (MBSB) in the Central Eastern Desert of Egypt by examining its structural styles, kinematics and geometry. Our study revealed the existence of prevalent dextral and minor sinistral conjugate shear zones. The MBSB is metamorphic belt (greenschist-amphibolite) characterized by at least three post-collisional (740-540 Ma) ductile Neoproterozoic deformation events (D1, D2 and D3) followed by a brittle neotectonic deformation (D4). D1 event produced early top-to-the-northwest thrust displacements due to NW-SE shortening. D2 produced discrete zones of NNW-trending upright folds and culminated in initiation of major NW-trending sinistral shear zones of the Najd Fault System (NFS, at c. 640-540 Ma ago) as well as steeply dipping S2 foliation, and shallowly plunging L2 lineation. NW-to NNW-trending F2 folds are open to steep and vary in plunge from horizontal to vertical. D2 deformational fabrics are strongly overprinted by D3 penetrative structures. D3 is characterized by a penetrative S3 foliation, steeply SE- to NW-plunging and shallowly NE-plunging stretching lineations (L3), asymmetric and sheath folds (F3) consistent with dextral sense of movement exhibited by delta- and sigma-type porphyroclast systems and asymmetric boudinage fabrics. D2-D3 represent a non-coaxial progressive event formed in a dextral NE- over NW-sinistral shear zone during a partitioned transpression in response to E-W-directed compression during oblique convergence between East and West Gondwana developed due to closure of the Mozambique Ocean and amalgamation of the Arabian-Nubian Shield in Cryogenian-early Ediacaran time.

SHUTTLE IMAGING RADAR PROVIDES FRAMEWORK FOR SUBSURFACE GEOLOGIC EXPLORATION IN EGYPT AND SUDAN.

USGS Publications Warehouse

Breed, Carol S.; McCauley, John F.; Schaber, Gerald G.

1984-01-01

Shuttle Imaging Radar provides a pictorial framework to guide exploration for mineral resources (potential placers), groundwater sources, and prehistoric archaeological sites in the Western Desert of Egypt and Sudan. Documented penetration by the SIR-A signal of dry surficial sediment to depths of a meter or more revealed bedrock geologic features and networks of former stream valleys otherwise concealed beneath windblown sand, alluvium, and colluvial deposits. 'Radar units' mapped on SIR-A images according to relative brightness and degree of mottling correspond to subsurface geologic and topographic features identified in more than 50 test pits. Petrologic examination of pit samples confirms that a variety of depositional environments existed in this now hyper-arid region before it was mantled by windblown sand sheets and dunes. Wet sand was discovered in two buried valleys shown on the radar images and located in the field with the aid of co-registered maps and Landsat images, and a satellite navigation device. Buried valleys whose streams once traversed mineralized zones are potential sites of placers (gold, tin).

Sonoran Desert: Fragile Land of Extremes

USGS Publications Warehouse

Produced and Directed by Wessells, Stephen

2003-01-01

'Sonoran Desert: Fragile Land of Extremes' shows how biologists with the U.S. Geological Survey work with other scientists in an effort to better understand native plants and animals such as desert tortoises, saguaro cacti, and Gila monsters. Much of the program was shot in and around Saguaro National Park near Tucson, Arizona. Genetic detective work, using DNA, focuses on understanding the lives of tortoises. Studies of saguaros over many decades clarify how these amazing plants reproduce and thrive in the desert. Threats from fire, diseases in tortoises, and a growing human population motivate the scientists. Their work to identify how these organisms live and survive is a crucial step for the sound management of biological resources on public lands. This 28-minute program, USGS Open-File Report 03-305, was shot entirely in high definition video and produced by the USGS Western Ecological Research Center and Southwest Biological Science Center; produced and directed by Stephen Wessells, Western Region Office of Communications.

Eyewitness introduction to Egypt: "The gift of the Nile".

PubMed

Brown, Geraldine

2009-01-01

Northeastern corner of Africa, lying at the crossroads between the two continents of Europe and Asia (in the Sinai Peninsula), while bordering Libya, Sudan, Israel and the Red Sea. Egypt is the most ancient tourist country in the world. Several health fact-finding missions in the last few years were made to this small country that is frequently defined by the Valley of the Nile. With the spreading deserts on either side, or a very rich heritage of ancient relics, these scenic vistas are without equal elsewhere in the world. Although there are significant cultural differences among the population, Egypt has a long history of ethnic and religious compassion. Among the many rarities, main tourist attractions include the three great Pyramids of Giza and the Sphinx, amazing ancient wonders of the world. These fact-finding missions included how health and medical care are defined, how people and culture are intertwined with its physical features, land use, and the economy and its resources.

Peculiar Feldspar And Quartz Inclusions Within Zircons From Anorthosites, North Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

Eliwa, H. A.; Dawoud, M. I.; Khalaf, I. M.; Negendank, J. F.; Itaya, T.

2004-12-01

Zircons from three anorthosite outcrops along Wadi Dib area, north Eastern Desert of Egypt contain abundant and conspicuous inclusions of quartz, feldspar, amphibole and apatite. These anorthosites, as (50-100m thick) layers, represent the top of mafic-ultramafic intrusions exhibiting rhythmic layering visible by reputation of melanocratic and leucocratic layers. Field and microscopic studies exhibit that these anorthosites were affected by the action of residual magmatic solutions associated with the late stage crystallization of the younger granites, which modified their mineralogical composition. They are composed totally of plagioclase with subordinate amount of clinoenstatite, augite, amphibole, biotite, K-feldspar, and quartz. Accessories are magnetite, ilmenite, apatite and zircon. The abundance and the mode of occurrence of K-feldspar, quartz, and biotite with apatite and zircon among the megacrysts suggest their formation is ascribed to the interaction with the residual solutions. The microprobe data exhibit difference between feldspar and amphiboles contained herein zircons and those as anorthosite mineral constituents. The genetic relationship between zircons and their inclusions suggests later growth of zircons than inclusions and most probably at the final stage of rock modification. Zircons are magmatic and found in the interstitial feldspar and quartz among plagioclase megacrysts in aggregates or as individual grains. The microscopic and SEM images investigation exhibit that most zircons are subhedral to euhedral equant and prismatic crystals. Most zircons have same range of crystal morphologies and internal growth structures with predominance of prism /{100/} and pyramid /{101/} and occasionally prism /{110/} and pyramid /{111/}. No evidences for poly-faceted grains, inherited cores or later overgrowths were detected. CL images distinguished zircons with visible core-rim structures and others with regular and continuous growth zones contained herein

Paleoenvironmental signals and paleoclimatic condition of the Early Maastrichtian oil shales from Central Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

Fathy, Douaa; Wagreich, Michael; Zaki, Rafat; Mohamed, Ramadan S. A.

2016-04-01

Early Maastrichtian oil shales are hosted in the Duwi Formation of the Central Eastern Desert, Egypt. The examined member represents up to 20% of the total Duwi Formation. This interval is mainly composed of siliciclastic facies, phosphorites facies and carbonate facies. Oil shales microfacies is mainly composed of smectite, kaolinite, calcite, fluorapatite, quartz and pyrite. They are enriched in a number of major elements and trace metals in particular Ca, P, V, Ni, Cr, Sr, Zn, Mo, Nb, U and Y compared to the post-Archaean Australian shale (PAAS). Chondrite-normalized REEs patterns of oil shales for the studied area display light rare earth elements enrichment relatively to heavy rare earth elements with negative Ce/Ce* and Eu/Eu* anomalies. The most remarkable indicators for redox conditions are enrichments of V, Mo, Ni, Cr, U content and depletion of Mn content. Besides, V/V+Ni, V/Ni, U/Th, Ni/Co, authigentic uranium ratios with presence of framboidal shape of pyrite and its size are reflecting the deposition of these shales under marine anoxic to euxinic environmental conditions. Additionally, the ratio of Strontium (Sr) to Barium (Ba) Sr/Ba reflected highly saline water during deposition. Elemental ratios critical to paleoclimate and paleoweathering (Rb /Sr, Al2O3/TiO2), CIA values, binary diagram between (Al2O3+K2O+Na2O) and SiO2 and types of clay minerals dominated reflect warm to humid climate conditions prevailing during the accumulation of these organic-rich petroleum source rocks.

ASTER View of Sharm El Sheik, Egypt

NASA Image and Video Library

2000-10-20

The Red Sea golf resort in Sharm El Sheik, Egypt, where President Clinton met with Israeli Prime Minister Ehud Barak and Palestinian Authority President Yasser Arafat, stands out against the desert landscape in this image acquired on August 25, 2000. This image of the southern tip of the Sinai Peninsula shows an area about 30 by 40 kilometers (19 by 25 miles) in the visible and near infrared wavelength region. Vegetation appears in red. The blue areas in the water at the top and bottom of the image are coral reefs. The airport is visible just to the north of the golf resort. http://photojournal.jpl.nasa.gov/catalog/PIA02667

Genesis of the Abu Marawat gold deposit, central Eastern Desert of Egypt

NASA Astrophysics Data System (ADS)

Zoheir, Basem A.; Akawy, Ahmed

2010-06-01

Gold mineralisation at the Abu Marawat mine, central Eastern Desert of Egypt, is related to a system of massive and sheared, milky quartz veins cutting a sequence of Neoproterozoic island arc metavolcanic/volcaniclastic rocks and related banded iron formation (BIF). Sulphide-bearing quartz veins and related hydrothermal breccia bodies display a range of textures including sheared, boudinaged and recrystallised quartz, open space filling and microbreccia. These variable textures imply a complex history of crack-seal mechanism characterising the relation between mineral deposition and a major N-S-trending shear zone, during a late brittle-ductile deformation event which affected the area at about 550 Ma. Gold-base metal mineralisation is associated with brecciation and fracturing of the iron ore bands, close to silicified shears and related quartz veins. The auriferous quartz lodes are characterised by the occurrence of visible pyrite-chalcopyrite ± pyrrhotite ± sphalerite ± galena mineralisation. Gold is refractory in pyrite and chalcopyrite, but rare visible gold/electrum and telluride specks were observed in a few samples. Hydrothermal alteration includes pervasive silicification, pyritisation, sericitisation, carbonatisation confined to a delicate set of veins and altered shears, and a more widespread propylitic alteration assemblage (quartz + chlorite + pyrite + calcite ± epidote). Fluid inclusion petrography and microthermometric studies suggest heterogeneous trapping of a low-salinity (1.4-6.7 wt.% eq. NaCl) aqueous solution and a carbonic fluid. Evidence for fluid immiscibility during ore formation includes variable liquid/vapour ratios in inclusions along individual trails and bulk inclusion homogenisation into liquid and occasionally to vapour at comparable temperatures. The trapping conditions of intragranular aqueous-carbonic inclusions approximate 264-378 °C at 700-1300 bar. Similar temperature estimates have been obtained from Al

Recent trends of desert tortoise populations in the Mojave Desert

USGS Publications Warehouse

Corn, Paul Stephen

1994-01-01

The desert tortoise, Gopherus agassizii (Cooper), was listed as threatened in the Mojave Desert in 1990. Important factors for the listing were severe recent mortality in tortoise populations and a general decline throughout this century. Recent trends in tortoise populations were examined by plotting total captures of adult and juvenile tortoises from 2.6-km2 study plots, rather than by mark-and-recapture population estimates. Changes in relative abundance of tortoises were greatest among large tortoises in the western Mojave Desert, which may reflect high levels of human disturbance, and among small tortoises, which may reflect either lower ability of searches to detect small tortoises or greater mortality of tortoises during drought conditions in 1986-90, or both factors. Further collection of data on population trends is needed, particularly in years with higher-than-average precipitation. Retention of the threatened status of the tortoise is a conservative strategy for the conservation of natural resources but should be reassessed when additional data are available.

Earth observation taken by the Expedition 43 crew

NASA Image and Video Library

2015-05-08

ISS043182398 (05/08/2015) --- Another view of the northern African Great Sand Sea, Libyan Desert and western Egypt with orange parallel dunes taken on May 8th 2015 by NASA astronaut Scott Kelly on the International Space Station.

Construction of a hydrologic model for estimating Wadi runoff and ground water recharge in the Eastern Desert, Egypt.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gheith, H.; Sultan, M.; Environmental Research

2002-06-10

We constructed a hydrologic model to estimate the groundwater recharge rate for alluvial aquifers of the Eastern Desert from sporadic precipitation over the Red Sea hills. To estimate initial losses over sub-basins, transmission losses through channel routing, and downstream runoff, we developed an integrated model combining spatial rainfall distribution, an appropriate basin unit hydrograph, and appropriate infiltration parameters. Watersheds and stream networks identified from digital terrain elevation data were verified by comparison with co-registered Landsat thematic mapper scenes and geologic maps. Records of a November 1994 storm event acquired from rain gauges along the Nile River and the Red Seamore » shore were used to generate a spatial precipitation distribution for the study area. A 2 hour design hyetograph was adopted from rain gauge data for the 1994 flood event. The model was tested against records from the November 1994 flood event at the outlets of the Tarfa and Hammamat watersheds. Groundwater recharge rates were estimated for the alluvial aquifers within the major watersheds of the north Eastern Desert. We estimated that during the 1994 flood event, the ground water recharge through transmission losses ranged from 21 to 31% (Tarfa: 15.8 x 10{sup 6} m{sup 3}; Asyuti: 20 x 10{sup 6} m{sup 3}, Qena: 49 x 10{sup 6} m{sup 3}, Hammamat: 59 x10{sup 6} m{sup 3}) of the precipitated volume. The initial losses ranged from 65 to 77%. Only 3-7% of the precipitation reached the watershed outlets. Archival data show that rainfall events of the size of the November 1994 storm or larger occur every 40 months; thus, the annual recharge rates for the Tarfa, Asyuti, Qena, and Hammamat alluvial aquifers are estimated at 4.7 x 10{sup 6} m{sup 3}, 6 x 10{sup 6} m{sup 3}, 14.7 x 10{sup 6} m{sup 3}, and 17.7 x10{sup 6} m{sup 3}, respectively. Implications for the use of these renewable ground waters and similar water resources in other arid areas of Egypt and in

Desert landforms of southwest Egypt: A basis for comparison with Mars

NASA Technical Reports Server (NTRS)

El-Baz, F. (Editor); Maxwell, T. A. (Editor)

1982-01-01

Geologic interpretations of The Gilf Kebir-Uweinat of Apollo-Soyuz photographs were verified. The photographs and LANDSAT images showed features reminiscent of those depicted by Mariner and Viking missions to Mars. These features were to better understand their morphologic analogs on Mars. It is indicated that climate change played a significant role in the formation of the eastern Sahara. It is also revealed that correlations between the eolian features in southwestern Egypt and the wind blown patterns on the surface of Mars result in a better understanding of eolian activity on both planets.

Remote sensing detection of gold related alteration zones in Um Rus area, Central Eastern Desert of Egypt

NASA Astrophysics Data System (ADS)

Amer, Reda; Kusky, Timothy; El Mezayen, Ahmed

2012-01-01

Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) and Phased Array L-band Synthetic Aperture Radar (PALSAR) images covering the Um Rus area in the Central Eastern Desert of Egypt were evaluated for mapping geologic structure, lithology, and gold-related alteration zones. The study area is covered by Pan-African basement rocks including gabbro and granodiorite intruded into a variable mixture of metavolcanics and metasediments. The first three principal component analyses (PCA1, PCA2, PCA3) in a Red-Green-Blue (RGB) of the visible through shortwave-infrared (VNIR + SWIR) ASTER bands enabled the discrimination between lithological units. The results show that ASTER band ratios ((2 + 4)/3, (5 + 7)/6, (7 + 9)/8) in RGB identifies the lithological units and discriminates the granodiorite very well from the adjacent rock units.The granodiorites are dissected by gold-bearing quartz veins surrounded by alteration zones. The microscopic examination of samples collected from the alteration zones shows sericitic and argillic alteration zones. The Spectral Angle Mapper (SAM) and Spectral Information Divergence (SID) supervised classification methods were applied using the reference spectra of the USGS spectral library. The results show that these classification methods are capable of mapping the alteration zones as indicated by field verification work. The PALSAR image was enhanced for fracture mapping using the second moment co-occurrence filter. Overlying extracted faults and alteration zone classification images show that the N30E and N-S fractures represent potential zones for gold exploration. It is concluded that the proposed methods can be used as a powerful tool for ore deposit exploration.

Egypt's fundamentalists say condoms immoral.

PubMed

Soliman, S

1995-06-01

The first AIDS case in Egypt was reported almost 10 years ago, yet Egypt still does not have reliable statistics on the HIV/AIDS epidemic (officially, 513 HIV infections and 88 AIDS cases; more likely, 3000 and 10,000, respectively). HIV/AIDS bears a stigma. The government claims that every HIV-infected Egyptian acquired the infection through a blood transfusion while in the Gulf or through sexual intercourse in Europe. Cultural, social, and religious norms that discourage promiscuity may explain the low HIV/AIDS rate but these same taboos put women at risk by making it difficult for them to protect themselves. Islamic fundamentalist women reinforce the Islamic principle of forbidding sex education. They consider AIDS a plague of immoral Western society. They refuse to accept the fact that many men do not practice safer sex. These women consider condoms immoral. They think God will curse women who refuse to have sexual intercourse at their husbands' bidding. Many nongovernmental organizations consider an intensive education program as the only means to avert disaster. Egypt has yet to implement its model AIDS program. All hospitals in Cairo and some hospitals in rural areas have equipment to test for HIV. Surveillance systems have been limited to high risk groups. In Egypt, it is mandatory to test foreigners for HIV. Prisoners, prostitutes, homosexuals, and blood donors are tested randomly without their consent. Positive results are often reported to authorities before the persons learn their HIV status. A campaign for widespread sex education is the only action recommended so far. It includes a mass media component and community meetings and conferences. An Egyptian physician has found an anti-viral drug that stimulates the immune system, but his work does not receive much coverage outside Egypt. Egyptians need to tackle their cultural taboos about discussion of sex to curb the HIV/AIDS epidemic.

Prevalence of primary headache disorders in Fayoum Governorate, Egypt.

PubMed

El-Sherbiny, Naglaa A; Masoud, Mohamed; Shalaby, Nevin M; Shehata, Hatem S

2015-01-01

There is abundance of epidemiological studies of headache in developed and western countries; however, data in developing countries and in Egypt are still lacking. This study aims to detect the prevalence of primary headache disorders in both urban and rural sectors in Fayoum governorate, Egypt. A total of 2600 subjects were included using multi-stage stratified systematic random sampling, with respondent rate of 91.3 %. A pre-designed Arabic version, interviewer-administered, pilot tested structured questionnaire was developed according to The International Classification of Headache Disorders, 3rd edition (beta version), and this questionnaire was validated and the strength of agreement in headache diagnosis was good. The 1-year headache prevalence was 51.4 %, which was more prevalent in urban dwellers. The most common primary headache type was episodic tension type headache (prevalence; 24.5 %), followed by episodic migraine (prevalence; 17.3 %), both types peaked in midlife. Headache disorders were more common in females with exception of cluster headache that showed the expected male dominance. The risk of chronic headache increased more than one fold and half when the participants were females, married, and in those with high education. More than 60 % of our participants did not seek medical advice for their headaches problem; this percentage was higher in rural areas. Primary headache disorders are common in Egypt; prevalence rate was comparable with western countries with exception of episodic tension headache. Still headache is under-estimated and under-recognized in Egypt and this problem should be targeted by health care providers.

Fog water chemistry in the Namib desert, Namibia

NASA Astrophysics Data System (ADS)

Eckardt, Frank D.; Schemenauer, Robert S.

This study documents the ion concentrations and ion enrichment relative to sea water, in Namib Desert fog water, with the purpose of establishing its suitability for future fogwater collection schemes, while also examining claims that Namib Desert fog water carries exceptionally high concentrations of sulphate, which may be responsible for the formation of gypsum deposits in the desert. The work suggests that Namibian fog water is at least as clean as has been reported from other coastal deserts in South America and Arabia, and provides a source of very clean water for the coastal desert region of south-western Africa. It does not appear that fog is an efficient sulphur source for the formation of the gypsum deposits, unless rare events with high concentrations of marine sulphur compounds occur.

Nest site characteristics and nesting success of the Western Burrowing Owl in the eastern Mojave Desert

USGS Publications Warehouse

Longshore, Kathleen M.; Crowe, Dorothy E.

2013-01-01

We evaluated nest site selection at two spatial scales (microsite, territory) and reproductive success of Western Burrowing Owls (Athene cunicularia hypugaea) at three spatial scales (microsite, territory, landscape) in the eastern Mojave Desert. We used binary logistic regression within an information-theoretic approach to assess factors influencing nest site choice and nesting success. Microsite-scale variables favored by owls included burrows excavated by desert tortoise (Gopherus agassizii), burrows with a large mound of excavated soil at the entrance, and a greater number of satellite burrows within 5 m of the nest burrow. At the territory scale, owls preferred patches with greater cover of creosote bush (Larrea tridentata) within 50 m of the nest burrow. An interaction between the presence or absence of a calcic soil horizon layer over the top of the burrow (microsite) and the number of burrows within 50 m (territory) influenced nest site choice. Nesting success was influenced by a greater number of burrows within 5 m of the nest burrow. Total cool season precipitation was a predictor of nesting success at the landscape scale. Conservation strategies can rely on management of habitat for favored and productive nesting sites for this declining species.

Management of Egypt's Surface and Groundwater Resources: Present and Future

NASA Astrophysics Data System (ADS)

Sultan, M.; Ahmed, M.; Yan, E.; Milewski, A.; Mohamed, L.; Farag, A. Z. A.

2014-12-01

The River Nile is the main source of fresh water in Egypt. Most of Egypt's River Nile water (>85%) originates as precipitation over the Ethiopian highlands and is channeled by the Blue Nile. The construction (years: 2011 to 2017) of the Renaissance Dam (reservoir capacity: 70 x 109m3) on the Blue Nile poses an extreme threat to Egypt's population. If the reservoir was to be filled in 7 years, Egypt will lose (during each of 7 years following dam completion) a minimum of 15 x 109m3 of its annual allocation (55 x 109m3) to reservoir filling (10 x 109m3), evaporation (3.5 x 109m3), and infiltration (1.5 x 109m3). Three solutions are proposed: Solution I takes advantage of the cyclicity of Nile floods and is based on findings from a calibrated (against temporal head data) unconfined 2-dimensional transient groundwater flow model for Lake Nasser and surroundings and a calibrated (against lake levels) surface water model. Models show with time: (1) losses to infiltration will decrease (1975-193: 58.4 109m3; 1993-2001: 43.6 x 109m3) due to silting of Lake bottom and encroachment of excess Lake Nasser water will increase (e.g., 1975-1993: none; 1993-2001: 17 x 109m3). We propose to develop sustainable agricultural in the Western Desert: (1) In high flood years, excess Lake Nasser water (e.g., 1993-2001: 17 x 109m3) is channeled across the plateau bounding (from west) the River Nile valley to artificially recharge the Nubian Sandstone Aquifer System (NSAS) that crops out west of the plateau and, (2) in low flood years, we extract the recharged groundwater. Solution II calls on mining the NSAS at reasonable rates. Using temporal (January 2003 - September 2012) Gravity Recovery and Climate Experiment (GRACE) data we estimate the annual depletion rates at 2 x 109m3 due to artificial extraction (1.5 x 109m3) and natural discharge (0.5 x 109m3). Assuming current GRACE depletion rates, the recoverable groundwater (5,180 x 109m3) will last for 2500 years; if we were to quadruple

Ground-water quality and geochemistry, Carson Desert, western Nevada

USGS Publications Warehouse

Lico, Michael S.; Seiler, R.L.

1994-01-01

Aquifers in the Carson Desert are the primary source of drinking water, which is highly variable in chemical composition. In the shallow basin-fill aquifers, water chemistyr varies from a dilute calcium bicarbonate-dominated water beneath the irrigated areas to a saline sodium chloride- dominated water beneath unirrigated areas. Water samples from the shallow aquifers commonly have dissolved solids, chloride, magnesium, sulfate, arsenic, and manganese concentrations that exceed State of Nevada drinking-water standards. Water in the intermediante basin-fill aquifers is a dilute sodium bicarbonate type in the Fallon area and a distinctly more saline sodium chloride type in the Soda Lake-Upsal Hogback area. Dissolved solids, chloride, arsenic, fluoride, and manganese concen- trations commonly exceed drinking-water standards. The basalt aquifer contains a dilute sodium bicarbonate chloride water. Arsenic concentrations exceed standards in all sampled wells. The concen- trations of major constituents in ground water beneath the southern Carson Desert are the result of evapotranspiration and natural geochemical reactions with minerals derived mostly from igneous rocks. Water with higher concentrations of iron and manganese is near thermodynamic equilibrium with siderite and rhodochrosite and indicates that these elements may be limited by the solubility of their respective carbonate minerals. Naturally occurring radionuclides (uranium and radon-222) are present in ground water from the Carson Desert in concen- tratons higher than proposed drinking-water standards. High uranium concentrations in the shallow aquifers may be caused by evaporative concentration and the release of uranium during dissolution of iron and manganese oxides or the oxidation of sedimentary organic matter that typically has elevated uranium concentrations. Ground water in the Carson Desert does not appear to have be contaminated by synthetic organic chemicals.

Seasonal cycle of desert aerosols in western Africa: analysis of the coastal transition with passive and active sensors

NASA Astrophysics Data System (ADS)

Senghor, Habib; Machu, Éric; Hourdin, Frédéric; Thierno Gaye, Amadou

2017-07-01

The impact of desert aerosols on climate, atmospheric processes, and the environment is still debated in the scientific community. The extent of their influence remains to be determined and particularly requires a better understanding of the variability of their distribution. In this work, we studied the variability of these aerosols in western Africa using different types of satellite observations. SeaWiFS (Sea-Viewing Wide Field-of-View Sensor) and OMI (Ozone Monitoring Instrument) data have been used to characterize the spatial distribution of mineral aerosols from their optical and physical properties over the period 2005-2010. In particular, we focused on the variability of the transition between continental western African and the eastern Atlantic Ocean. Data provided by the lidar scrolling CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) onboard the satellite CALIPSO (Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observations) for the period 2007-2013 were then used to assess the seasonal variability of the vertical distribution of desert aerosols. We first obtained a good representation of aerosol optical depth (AOD) and single-scattering albedo (SSA) from the satellites SeaWiFS and OMI, respectively, in comparison with AERONET estimates, both above the continent and the ocean. Dust occurrence frequency is higher in spring and boreal summer. In spring, the highest occurrences are located between the surface and 3 km above sea level, while in summer the highest occurrences are between 2 and 5 km altitude. The vertical distribution given by CALIOP also highlights an abrupt change at the coast from spring to fall with a layer of desert aerosols confined in an atmospheric layer uplifted from the surface of the ocean. This uplift of the aerosol layer above the ocean contrasts with the winter season during which mineral aerosols are confined in the atmospheric boundary layer. Radiosondes at Dakar Weather Station (17.5° W, 14.74° N) provide

Phylogeographic structure and historical demography of the western diamondback rattlesnake (Crotalus atrox): A perspective on North American desert biogeography.

PubMed

Castoe, Todd A; Spencer, Carol L; Parkinson, Christopher L

2007-01-01

The western diamondback rattlesnake (Crotalus atrox) is a prominent member of North American desert and semi-arid ecosystems, and its importance extends from its impact on the region's ecology and imagery, to its medical relevance as a large deadly venomous snake. We used mtDNA sequences to identify population genetic structure and historical demographic patterns across the range of this species, and relate these to broader patterns of historical biogeography of desert and semi-arid regions of the southwestern USA and adjacent Mexico. We inferred a Late Pliocene divergence between peninsular and continental lineages of Crotalus, followed by an Early Mid Pleistocene divergence across the continental divide within C. atrox. Within desert regions (Sonoran and Chihuahuan Deserts, Southern Plains, and Tamaulipan Plain) we observed population structure indicating isolation of populations in multiple Pleistocene refugia on either side of the continental divide, which we attempt to identify. Evidence of post-glacial population growth and range expansion was inferred, particularly in populations east of the continental divide. We observed clear evidence of (probably recent) gene flow across the continental divide and secondary contact of haplotype lineages. This recent gene flow appears to be particularly strong in the West-to-East direction. Our results also suggest that Crotalus tortugensis (Tortuga Island rattlesnake) and a population of 'C. atrox' inhabiting Santa Cruz Island (in the Gulf of California) previously suggested to be an unnamed species, are in fact deeply phylogenetically nested within continental lineages of C. atrox. Accordingly, we suggest C. tortugensis and 'C. atrox' from Santa Cruz Island be placed in the synonymy of C. atrox.

Morphodynamic implications for shoreline management of the western-Mediterranean sector of Egypt

NASA Astrophysics Data System (ADS)

Frihy, Omran E.

2009-09-01

Although the western-Mediterranean coast of Egypt between Sallum and Alexandria, ~550 km long, has maintained a considerable equilibrium throughout history, developers have built traditional protective structures in an effort to form sheltered recreational beaches without taking into consideration its geomorphologic characteristics, coastal processes and their harmful impact on the coastal environment and human safety. The improper practices in this environmentally valuable region have induced us to undertake an initiative to carry out a morphodynamic analysis to provide a framework for understanding the relationship between coastal morphology and the prevailing dynamic forces. Based on the degree of natural protection or wave sheltering, the study shoreline can be categorized into four distinct morphotypical stretches: (1) high-energy wave-exposed shores and the outer margins of the rocky headlands, (2) moderate to high wave-energy beaches along semi-exposed embayments and bays mostly downdrift of the rocky headlands, (3) low-wave energy at semi-exposed headland lee-sided and pocket beaches, and (4) calm wave-sheltered enclosing water basins for safe anchorages, moorings and recreation beaches. The results deducted will have practical applications for shoreline management initiatives regarding sustained sites suitable for future beachfront development such as safe swimming conditions, sport facilities, water intakes and sheltered areas for vessels. In addition, benefits realized by the understanding of the morphodynamic processes would enhance our awareness of the significance of the role of western coast morphodynamics in supporting sustainable development via shoreline management. As far as sustainability is concerned, the selection of appropriate sites would help avoiding or minimizing the formation of the hard structures needed for creating safe recreation beaches. On a national scale, results reached could provide reliable database for information that can be

Aerosol transport over the western Mediterranean basin: Evidence of the contribution of fine particles to desert dust plumes over Alborán Island

NASA Astrophysics Data System (ADS)

Valenzuela, A.; Olmo, F. J.; Lyamani, H.; Granados-Muñoz, M. J.; Antón, M.; Guerrero-Rascado, J. L.; Quirantes, A.; Toledano, C.; Perez-Ramírez, D.; Alados-Arboledas, L.

2014-12-01

Eight months (June 2011 to January 2012) of aerosol property data were obtained at the remote site of Alborán Island (35.95°N, 3.03°W) in the western Mediterranean basin. The aim of this work is to assess the aerosol properties according to air mass origin and transport over this remote station with a special focus on air mass transport from North Africa. For air masses coming from North Africa, different aerosol properties showed strong contributions from mineral dust lifted from desert areas. Nevertheless, during these desert dust intrusions, some atmospheric aerosol properties are clearly different from pure mineral dust particles. Thus, Angström exponent α(440-870) presents larger values than those reported for pure desert dust measured close to dust source regions. These results combine with α(440, 670) - α(670, 870) ≥ 0.1 and low single scattering albedo (ω(λ)) values, especially at the largest wavelengths. Most of the desert dust intrusions over Alborán can be described as a mixture of dust and anthropogenic particles. The analyses support that our results apply to North Africa desert dust air masses transported from different source areas. Therefore, our results indicate a significant contribution of fine absorbing particles during desert dust intrusions over Alborán arriving from different source regions. The aerosol optical depth data retrieved from Sun photometer measurements have been used to check Moderate Resolution Imaging Spectroradiometer retrievals, and they show reasonable agreement, especially for North African air masses.

Acute kidney injury following rhabdomyolysis and sepsis after non-poisonous desert monitor bite.

PubMed

Gupta, Poonam; Verma, Pradeep Kumar

2017-10-01

The desert monitor, Varanus griseus , is a species of desert monitor lizard found in North-Western India. They are believed to be non-poisonous. We report a case of Indian desert monitor bite leading to acute renal failure following rhabdomyolysis and severe sepsis. Prompt diagnosis and treatment resulted in the favourable outcome. This is author's intent to highlight the complication that may occur after Indian desert monitor bite.

Petrography and geochemistry of the Middle Miocene Gebel El Rusas sandstones, Eastern Desert, Egypt: Implications for provenance and tectonic setting

NASA Astrophysics Data System (ADS)

Zaid, Samir M.

2017-10-01

Petrography and bulk rock geochemistry of the Middle Miocene sandstones of the lower and upper members of Gebel El Rusas Formation along the Egyptian Red Sea Coastal plain, have been investigated to determine the provenance, tectonic setting, and weathering condition of this formation. The Lower Member is formed mainly of sandstones and conglomerates with clay interbeds. The Upper Member is more calcareous and formed mainly of sandstones and limestones with marls and clays intercalations. Petrographically, the Lower Member sandstones are mostly immature and classified as arkoses with an average framework composition of Q_{66}F_{29}R5, and the Upper Member sandstones are partly submature (more quartzose, less feldspathic) and classified as subarkoses with an average framework composition of Q_{80}F_{17}R3. The Gebel El Rusas sandstones are enriched in Sr, Ba, Zr and Rb and depleted in Co and U, as compared to UCC. The chemical index of alteration (CIA) values suggest moderate weathering conditions. The geochemistry results revealed that the Gebel El Rusas sandstones were derived from felsic-granitic source rocks and deposited in a passive margin of a synrift basin. The inferred tectonic setting for Middle Miocene Gebel El Rusas sandstones in the study area is consistent with the regional geology of the Eastern Desert of Egypt during Middle Miocene.

Late Neoproterozoic basement rocks of Meatiq area, Central Eastern Desert, Egypt: Petrography and remote sensing characterizations

NASA Astrophysics Data System (ADS)

Hassan, Safaa M.; El kazzaz, Yahiya A.; Taha, Maysa M. N.; Mohammad, Abdullah T.

2017-07-01

Meatiq dome is one of the mysteries of the basement rocks in Central Eastern Desert (CED) of Egypt. Its mode of formation, and tectonic evolution are still controversial and not fully understood. Satellite remote sensing is a powerful tool for geologic applications, especially in inaccessible regions of the Earth's surface. In this study, three proposed Landsat-8 band ratios (6/2, 6/7, (6/4*4/3)), (6/7, 6/4, 4/2), and (7/5, 7/6, 5/3) are successfully used for detailed geological mapping of the different lithological rock units exposed in Meatiq dome area in the CED. Landsat-8 Principal component (PC) images is also used for refinement the boundaries between the widely-exposed rock units in the study area. Fourteen spectral bands of Advanced Space borne Thermal Emission and Reflection Radiometer (ASTER) data are successfully used to emphasize the distribution of some rock forming minerals (i.e. muscovite, quartz, ferrous oxides, ferrous silicates and hydroxyl-bearing minerals) in the lithological rock units of Meatiq dome area. ASTER muscovite index (B7/B6) and quartz index (B14/B12), ferrous iron index (B5/B3), ferrous silicates index (B5/B4), mafic index (B12/B13) and hydroxyl-bearing minerals index ((B7/B6)*(B4/B6)) discriminate muscovite bearing rocks, Granitoids, and other felsic rocks, amphibolite and other mafic rocks. The proposed image processing methods effectively discriminates between four granitic varieties existed in Meatiq area. They are namely; Abu Ziran, Ariki, Fawakhir and Atalla Plutons. This study reveals that the applied data of ASTER and Landsat-8 enhanced images produced a modified geological map with well emphasized rock units which are verified with field observations, and petrographic study.

Phylogeography of Beck's Desert Scorpion, Paruroctonus becki, reveals Pliocene diversification in the Eastern California Shear Zone and postglacial expansion in the Great Basin Desert.

PubMed

Graham, Matthew R; Jaeger, Jef R; Prendini, Lorenzo; Riddle, Brett R

2013-12-01

The distribution of Beck's Desert Scorpion, Paruroctonus becki (Gertsch and Allred, 1965), spans the 'warm' Mojave Desert and the western portion of the 'cold' Great Basin Desert. We used genetic analyses and species distribution modeling to test whether P. becki persisted in the Great Basin Desert during the Last Glacial Maximum (LGM), or colonized the area as glacial conditions retreated and the climate warmed. Phylogenetic and network analyses of mitochondrial cytochrome c oxidase 1 (cox1), 16S rDNA, and nuclear internal transcribed spacer (ITS-2) DNA sequences uncovered five geographically-structured groups in P. becki with varying degrees of statistical support. Molecular clock estimates and the geographical arrangement of three of the groups suggested that Pliocene geological events in the tectonically dynamic Eastern California Shear Zone may have driven diversification by vicariance. Diversification was estimated to have continued through the Pleistocene, during which a group endemic to the western Great Basin diverged from a related group in the eastern Mojave Desert and western Colorado Plateau. Demographic and network analyses suggested that P. becki underwent a recent expansion in the Great Basin. According to a landscape interpolation of genetic distances, this expansion appears to have occurred from the northwest, implying that P. becki may have persisted in part of the Great Basin during the LGM. This prediction is supported by species distribution models which suggest that climate was unsuitable throughout most of the Great Basin during the LGM, but that small patches of suitable climate may have remained in areas of the Lahontan Trough. Published by Elsevier Inc.

Egypt.

PubMed

1987-12-01

Attention in this discussion of Egypt is directed to the following: geography; the people; history; government and political conditions; the economy; defense; foreign relations; and relations between Egypt and the US. The population totaled 50.5 million in 1986 with an annual growth rate of 2.8%. The infant mortality rate is 102/1000 (1986), and life expectancy is 58.3 years. Located in the northeastern corner of Africa, Egypt has a land area of about 1 million square kilometers and is bounded by the Mediterranean Sea, Libya, Sudan, the Red Sea, the Gulf of Aqaba, and Israel. Egypt is the most populous country in the Arab world. Egyptians are a fairly homogenous people of Hamitic origin. Mediterranean and Arab influences appear in the north, and there is some mixing in the south with the Nubians of northern Sudan. Egypt has been a unified state for over 5000 years, and archeological evidence indicates that a developed Egyptian society has existed for considerably longer. The constitution of Egypt provides for a strong executive with authority vested in an elected president who can appoint 1 or more vice presidents, a prime minister, and a cabinet. Egypt's legislative body has 458 members -- 448 popularly elected and 10 appointed by the president. Power is concentrated in the hands of the president and the National Democratic Party's majority in the People's Assembly, but opposition parties organize, publish their views, and represent their followers at various levels in the political system. The process of gradual political liberalization begun by Sadat has continued under Mubarak. In fiscal year 1987 the gross domestic product (GDP) reached about US$30 billion. Agriculture and services each contribute about 1/3 of GDP; the remainder comes from industry, petroleum, mining, electricity, and construction. At this time, the Egyptian economy faces several challenges. In 1986 the government of Egypt initiated a major review of economic policy and initiated an economic

Middle Eocene echinoids from Gebel Qarara, Maghagh, Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

Ali, Mohamed Said M.

2017-09-01

The Middle Eocene echinoid fauna of Gebel Qarara is large and diverse. Twenty four species in seventeen genera are identified and described. Three species of them are new: Echinocyamus belali, Antillaster farisi and Metalia lindaae. The Caribbean genus Antillaster which is recorded for the first time from the Mediterranean region, suggests an east - west migration from the Tethys and Paratethys to the Caribbean region during the Eocene time by crossing the Atlantic Ocean in a westerly direction. The paleoecology and the paleogeography of the echinoid fauna are discussed. The paleoecological study appears to revel that the Middle Eocene rocks of that area were deposited in a shallow marine water conditions. Paleogeographically, 33.3% of the total echinoids are endemic to Egypt, 66.7% species are similar to that of the taxa of the adjacent countries.

The Regional Environmental Impacts of Atmospheric Aerosols over Egypt

NASA Astrophysics Data System (ADS)

Zakey, Ashraf; Ibrahim, Alaa

2015-04-01

Identifying the origin (natural versus anthropogenic) and the dynamics of aerosols over Egypt at varying temporal and spatial scales provide valuable knowledge on the regional climate impacts of aerosols and their ultimate connections to the Earth's regional climate system at the MENA region. At regional scale, Egypt is exposed to air pollution with levels exceeding typical air-quality standards. This is particularly true for the Nile Delta region, being at the crossroads of different aerosol species originating from local urban-industrial and biomass-burning activities, regional dust sources, and European pollution from the north. The Environmental Climate Model (EnvClimA) is used to investigate both of the biogenic and anthropogenic aerosols over Egypt. The dominant natural aerosols over Egypt are due to the sand and dust storms, which frequently occur during the transitional seasons (spring and autumn). In winter, the maximum frequency reaches 2 to 3 per day in the north, which decreases gradually southward with a frequency of 0.5-1 per day. Monitoring one of the most basic aerosol parameters, the aerosol optical depth (AOD), is a main experimental and modeling task in aerosol studies. We used the aerosol optical depth to quantify the amount and variability of aerosol loading in the atmospheric column over a certain areas. The aerosols optical depth from the model is higher in spring season due to the impacts of dust activity over Egypt as results of the westerly wind, which carries more dust particles from the Libyan Desert. The model result shows that the mass load of fine aerosols has a longer life-time than the coarse aerosols. In autumn season, the modelled aerosol optical depth tends to increase due to the biomass burning in the delta of Egypt. Natural aerosol from the model tends to scatter the solar radiation while most of the anthropogenic aerosols tend to absorb the longwave solar radiation. The overall results indicate that the AOD is lowest in winter

The Politics of Educational Transfer and Policymaking in Egypt

ERIC Educational Resources Information Center

Ibrahim, Ali S.

2010-01-01

For the past two centuries, western modern education has informed education policies and practices in Egypt. However, few researchers have analyzed the historical or current politics of educational transfer in this country. This article investigates the ways in which foreign transfer has influenced Egyptian education, both historically and…

Fluid evolution of Au-Cu zones in Um Balad area, North Eastern Desert of Egypt: Implications from mineral chemistry and fluid inclusions

NASA Astrophysics Data System (ADS)

Abd El Monsef, Mohamed; Salem, Ibrahim; Slobodník, Marek; Ragab, Ahmed

2018-07-01

Scanning electron microscope (SEM), Electron microprobe (EMPA) and fluid inclusion studies of the ore body, as well as geochemical analyses of country rocks were performed to determine the nature and characteristics of the mineralizing fluid responsible for Au-Cu deposits in Um Balad area, Northern Eastern Desert of Egypt. The Um Balad Au-Cu deposits are confined to well developed-quartz veins and veinlets cutting through the hosting country rocks. Petrographic and geochemical investigations of the hosting rocks distinguished between two main rock units; 1) metagabbro-diorite rocks with tholeiitic nature derived in island arc/continental margin tectonic regime, and 2) granodiorite rocks formed from calc-alkaline magma in continental margin regime. Wallrock alterations are represented by propylitic and argillic types. The mineralized quartz veins are striking in NE-SW direction and dipping between (35°-45°) in SE direction, other mineralized mafic dykes enriched with auriferous quartz veinlets are trending NE-SW and dipping 70°/SE. The main ore minerals are represented by gold, chalcopyrite, pyrite, sphalerite, malachite, covellite and goethite. While, geffroyite, cuprite, chrysocolla, pseudomalachite, britholite, wolframite, scheelite, hematite and rutile are detected as minor constituents. Fluid inclusions microthermometry and isochore calculations combined with chlorite geothermometry revealed that the Um Balad deposits were formed at temperature ranging from 305 °C to 325 °C and pressure between (100-500 bar). The mineralization had been developed in the shallow levels, beneath the water table at depth of 350-1760 m, rather than common mesothermal vein-type deposits in Egypt. Magmatic water have been suggested as the main source for the mineralized fluid. The transportation of the gold metal seems to be happen as bisulfide complexes in moderately acidic environment. The deposition was resulted from combination of changes in physico-chemical parameters

Gopherus agassizii: Desert tortoise

USGS Publications Warehouse

Berry, Kristen H.; Swingland, Ian Richard; Klemens, Michael W.

1989-01-01

The desert tortoise is one of four allopatric North American tortoises. It occurs in the Mojave and Sonoran deserts of the southwestern United States and Mexico.Auffenberg (1976) divided the genus Gopherus (consisting of four species, G. agassizi, G. berlandieri, G.flavomarginatus, and G. polyphemus) in two osteological groups. Bramble (1982), using morphological and palaeontological data, divided the genus Gopherus into two separate complexes, each with two species. He established a new genus, Scaptochelys, for agassizi and berlandieri, retaining Gopherus for polyphemus and flavomarginatus. Bour and Dubois (1984) noted that Xerobates Agassiz had priority over Scaptochelys Bramble. Using mitochondrial DNA (mtDNA), Lamb et al. (1989) evaluated the evolutionary relationships of the North American tortoises, particularly the desert tortoise. They concluded that the mtDNA analysis provides strong support for generic recognition of the two distinct species groups described by Bramble (1982).Until a few decades ago, the desert tortoise was widespread at lower elevations throughout the Mojave and Sonoran deserts of the U.S.A. In the northern and western parts of the geographic range, large and relatively homogeneous populations with densities exceeding 1,000/sq km extended throughout parts of California, and probably into Nevada and Utah. In terms of biomass, the tortoise played an important role in the ecosystems. In most areas, numbers have declined dramatically and the extent of populations has been reduced. Most populations are now isolated and low in numbers. Conservation of the desert tortoise is a highly visible and political issue in the U.S.A., but not in Mexico.

Reclaiming freshwater sustainability in the Cadillac Desert

PubMed Central

Sabo, John L.; Sinha, Tushar; Bowling, Laura C.; Schoups, Gerrit H. W.; Wallender, Wesley W.; Campana, Michael E.; Cherkauer, Keith A.; Fuller, Pam L.; Graf, William L.; Hopmans, Jan W.; Kominoski, John S.; Taylor, Carissa; Trimble, Stanley W.; Webb, Robert H.; Wohl, Ellen E.

2010-01-01

Increasing human appropriation of freshwater resources presents a tangible limit to the sustainability of cities, agriculture, and ecosystems in the western United States. Marc Reisner tackles this theme in his 1986 classic Cadillac Desert: The American West and Its Disappearing Water. Reisner's analysis paints a portrait of region-wide hydrologic dysfunction in the western United States, suggesting that the storage capacity of reservoirs will be impaired by sediment infilling, croplands will be rendered infertile by salt, and water scarcity will pit growing desert cities against agribusiness in the face of dwindling water resources. Here we evaluate these claims using the best available data and scientific tools. Our analysis provides strong scientific support for many of Reisner's claims, except the notion that reservoir storage is imminently threatened by sediment. More broadly, we estimate that the equivalent of nearly 76% of streamflow in the Cadillac Desert region is currently appropriated by humans, and this figure could rise to nearly 86% under a doubling of the region's population. Thus, Reisner's incisive journalism led him to the same conclusions as those rendered by copious data, modern scientific tools, and the application of a more genuine scientific method. We close with a prospectus for reclaiming freshwater sustainability in the Cadillac Desert, including a suite of recommendations for reducing region-wide human appropriation of streamflow to a target level of 60%. PMID:21149727

Reclaiming freshwater sustainability in the Cadillac Desert

USGS Publications Warehouse

Sabo, John L.; Sinha, Tushar; Bowling, Laura C.; Schoups, Gerrit H.W.; Wallender, Wesley W.; Campana, Michael E.; Cherkauer, Keith A.; Fuller, Pam L.; Graf, William L.; Hopmans, Jan W.; Kominoski, John S.; Taylor, Carissa; Trimble, Stanley W.; Webb, Robert H.; Wohl, Ellen E.

2010-01-01

Increasing human appropriation of freshwater resources presents a tangible limit to the sustainability of cities, agriculture, and ecosystems in the western United States. Marc Reisner tackles this theme in his 1986 classic Cadillac Desert: The American West and Its Disappearing Water. Reisner's analysis paints a portrait of region-wide hydrologic dysfunction in the western United States, suggesting that the storage capacity of reservoirs will be impaired by sediment infilling, croplands will be rendered infertile by salt, and water scarcity will pit growing desert cities against agribusiness in the face of dwindling water resources. Here we evaluate these claims using the best available data and scientific tools. Our analysis provides strong scientific support for many of Reisner's claims, except the notion that reservoir storage is imminently threatened by sediment. More broadly, we estimate that the equivalent of nearly 76% of streamflow in the Cadillac Desert region is currently appropriated by humans, and this figure could rise to nearly 86% under a doubling of the region's population. Thus, Reisner's incisive journalism led him to the same conclusions as those rendered by copious data, modern scientific tools, and the application of a more genuine scientific method. We close with a prospectus for reclaiming freshwater sustainability in the Cadillac Desert, including a suite of recommendations for reducing region-wide human appropriation of streamflow to a target level of 60%.

Recent environmental change and prehistoric human activity in Egypt and Northern Sudan

NASA Astrophysics Data System (ADS)

Nicoll, Kathleen

2004-03-01

This paper reviews the various Late Quaternary records that are available from western Egypt and northern Sudan, which includes more than 500 published radiocarbon dates and various sedimentary archives from local landscape components, including palaeolakes, soils, drainages (wadis), and archaeological sites. This palaeoenvironmental compilation frames the spatial and temporal context of local cultural activities when the region was most hospitable ˜9000-6000 BP; at this time, monsoonal weather influenced the portion of the African continental interior, creating enough convective rainfall for occasional surface water storage. In this part of the modern Sahara, rapid hydroclimatic changes play a key role in geomorphic evolution and resource availability. As 'watering holes' formed and dried up in the Early to Middle Holocene, Neolithic people developed various subsistence strategies, including opportunistic hunting of small animals (e.g. gazelle and hare), and food-related (e.g. wild sorghum, millet, and legumes) activities: gathering, plant cultivation and livestock-rearing. During its wettest phases during the 'monsoonal maximum,' the area was drought-prone, sustaining a meager steppe-shrub desert flora. Further desertification and aeolian deflation during the Middle and Late Holocene fostered technological innovation, migration and settlement, as well as the further development of agrarian communities and complex culture.

Sequence stratigraphy of the Maastrichtian-Paleocene succession at the Dakhla Oasis, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Hewaidy, Abdel Galil A.; Farouk, Sherif; Bazeen, Youssef S.

2017-12-01

The Maastrichtian-Paleocene succession at the Dakhla Oasis is marked by the presence of a typical Nile Valley Facies represented by the Dakhla and Tarawan formations in Edmonstone and Qur El Malik sections in the central and western parts of the oasis, while a mixed Nile Valley and Garra Al-Arbain facies represented by Dakhla, Kurkur and Tarawan formations in Teneida section in the eastern part of the oasis adjacent to the Abu Tartur Plateau. These sections were examined for their foraminiferal contents, lithologic characters and stratigraphic boundaries. The distribution of foraminifera in the studied sections is variable and inconstant, as the planktonics are concentrated only at certain levels, which may be considered as a time intervals of transgression and maximum flooding surfaces. Eight planktonic biozones are distinguished in this work; of theses two are of Maastrichtain age and six are of Paleocene age. Eight 3rd order depositional sequences are recognized in the studied Maastrichtian-Paleocene succession based on the time stratigraphic boundaries released from the planktonic foraminifera and sea level changes which are released from the paleoecologic interpretations. The distinguished sequences are subdivided into their systems tracts based on the paleobathymetric interpretations of P/B% and benthic biofacies analysis. These sequences are bounded by eight sequence boundaries (SB A - SB H) represented by unconformity surfaces and depositional hiatuses. The correlation of the sequence boundaries of the established depositional sequences with the eustatic sea level curve, suggesting that these depositional sequences were resulted from the interplay of eustatic sea-level changes and local tectonic activities.

Finite strain analysis of metavolcanics and metapyroclastics in gold-bearing shear zone of the Dungash area, Central Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

Kassem, Osama M. K.; Abd El Rahim, Said H.

2014-11-01

The Dungash gold mine area is situated in an EW-trending quartz vein along a shear zone in metavolcanic and metasedimentary host rocks in the Eastern Desert of Egypt. These rocks are associated with the major geologic structures, which are attributed to various deformational stages of the Neoproterozoic basement rocks. Field geology, finite strain and microstructural analyses were carried out and the relation-ships between the lithological contacts and major/minor structures have been studied. The R f/ϕ and Fry methods were applied on the metavolcano-sedimentary and metapyroclastic samples from 5 quartz veins samples, 7 metavolcanics samples, 3 metasedimentary samples and 4 metapyroclastic samples in Dungash area. Finite-strain data show that a low to moderate range of deformation of the metavolcano-sedimentary samples and axial ratios in the XZ section range from 1.70 to 4.80 for the R f/ϕ method and from 1.65 to 4.50 for the Fry method. We conclude that finite strain in the deformed rocks is of the same order of magnitude for all units of metavolcano-sedimentary rocks. Furthermore, the contact between principal rock units is sheared in the Dungash area under brittle to semi-ductile deformation conditions. In this case, the accumulated finite strain is associated with the deformation during thrusting to assemble nappe structure. It indicates that the sheared contacts have been formed during the accumulation of finite strain.

Earth observations during STS-58

NASA Image and Video Library

1998-07-28

STS058-92-064 (18 Oct-1 Nov 1993) --- This oblique view, looking northeast from central Egypt, shows great expanses of the sand covered and rocky Western Desert in the foreground (bottom). The dark patches bottom right are the Dakhla Oases on the south side of an escarpment. For centuries camel trains have moved from here to the Nile Valley, seen here as a broad green line winding through the desert. The northern half of Egypt's Nile appears here, from about the latitude of Luxor to the delta. Green colors indicate the small area of crops which feed Egypt's population of 55 million. The Nile Delta is partly obscured by a band of clouds, but can be discerned at the coast as a flattened triangle of green. The smaller triangle close by is the Faiyum Basin, a depression irrigated by water from the Nile. The coast of the Mediterranean Sea appears left.

Assessment study about using underground water for tilapia culture for the first time in El-Bahria Oasis Desert, Egypt.

PubMed

Abbas, Hossam H; Ali, Fagr Kh; Kenawy, Amany M

2008-01-01

The present study was carried out in El-Bahria Oasis desert (Giza-Egypt) for 8 months (March-October) as a new study to assess the culture of tilapia spp. in underground well water. The obtained results showed a significant increase (P<0.01) in the values of plasma total protein, glucose, AST (aspartate aminotransferase), ALT (alanine aminotransferase), creatinine, uric acid, sodium, potassium and magnesium as well as a significant decrease (P<0.01) in plasma total lipids and calcium concentration. Furthermore, iron content in some selected vital organs was increased gradually with time, the studied organs are arranged according to their iron content in the following order: spleen > liver > kidney > gills > muscle. Remarkable changes were observed in the chemical muscle composition where the results showed a significant increase (P<0.01) in muscle water content, total lipids and ash. However, a significant decrease (P<0.01) in muscle total protein at the end of the study was observed. The growth of all male farmed tilapia in well water with a 3.2 mg/l iron concentration was unexpected; despite the presence of this high concentration of iron, the weight gain of cultured fish was 250 +/- 14.5 g. Molecular techniques are used nowadays as a good indicator for assessing the alteration in the genomes. RAPD-PCR technique indicated appearance of some changes in polymorphism band patterns. There also exists a distinct distance between the band patterns of cultured fish (T) and control fish (C). Histopathlogical sections showed pathological alterations in liver, kidney gills and spleen and the obtained results were discussed.

Multi-scale forcing and the formation of subtropical desert and monsoon

NASA Astrophysics Data System (ADS)

Wu, G. X.; Liu, Y.; Zhu, X.; Li, W.; Ren, R.; Duan, A.; Liang, X.

2009-09-01

This study investigates three types of atmospheric forcing across the summertime subtropics that are shown to contribute in various ways to the occurrence of dry and wet climates in the subtropics. To explain the formation of desert over the western parts of continents and monsoon over the eastern parts, we propose a new mechanism of positive feedback between diabatic heating and vorticity generation that occurs via meridional advection of planetary vorticity and temperature. Monsoon and desert are demonstrated to coexist as twin features of multi-scale forcing, as follows. First, continent-scale heating over land and cooling over ocean induce the ascent of air over the eastern parts of continents and western parts of oceans, and descent over eastern parts of oceans and western parts of continents. Second, local-scale sea-breeze forcing along coastal regions enhances air descent over eastern parts of oceans and ascent over eastern parts of continents. This leads to the formation of the well-defined summertime subtropical LOSECOD quadruplet-heating pattern across each continent and adjacent oceans, with long-wave radiative cooling (LO) over eastern parts of oceans, sensible heating (SE) over western parts of continents, condensation heating (CO) over eastern parts of continents, and double dominant heating (D: LO+CO) over western parts of oceans. Such a quadruplet heating pattern corresponds to a dry climate over the western parts of continents and a wet climate over eastern parts. Third, regional-scale orographic-uplift-heating generates poleward ascending flow to the east of orography and equatorward descending flow to the west. The Tibetan Plateau (TP) is located over the eastern Eurasian continent. The TP-forced circulation pattern is in phase with that produced by continental-scale forcing, and the strongest monsoon and largest deserts are formed over the Afro-Eurasian Continent. In contrast, the Rockies and the Andes are located over the western parts of their

The Cretaceous glauconitic sandstones of Abu Tartur, Egypt

NASA Astrophysics Data System (ADS)

Pestitschek, Brigitte; Gier, Susanne; Essa, Mahmoud; Kurzweil, Johannes

2010-05-01

The Abu Tartur mine is located in the Western Desert of Egypt, 50 km west of El Kharga City. Geologically, the Abu Tartur plateau is built by a sequence of Upper Cretaceous (Campanian - Maastrichtian) phosphorites, black shales and glauconitic sandstones. The phosphate deposits are of great economic importance and have been mined since their discovery in 1967. Outcrop sections were measured, sampled, sedimentologically characterized and described. One specific glaucony layer was investigated mineralogically and chemically in detail and compared to a subsurface sample from the mine. Two depositional regimes can be interpreted based on sedimentary architecture and structures: 1) a deeper-water hemipelagic environment, where phosphorites and organic carbon-rich shales were deposited and 2) a shallower, prograding higher energy shelf environment with glauconies. From a sequence stratigraphic perspective 1) was deposited during the transgressive systems tract and the early highstand while 2) was deposited during the remaining highstand and a lowstand prograding wedge (Glenn & Arthur, 1990). Petrographic and SEM investigations show that the glaucony grains are of authochtonous origin. XRF, EMPA and thin-section analyses show that the glaucony grains from the outcrop differ significantly in their chemical composition, morphology and color from the grains of the mine sample. The fresh glauconies are enriched in Fe2O3 and K2O compared to the surface samples. XRD analyses of the clay fraction of the six outcrop samples and the mine sample show that the grains consist of illite(glauconite)/smectite mixed-layers, with more illite layers (80 %) in the mine sample. The charge distribution diagram muscovite-pyrophyllite-celadonite shows a clear trend from smectitic glaucony to illitic glaucony, the mine sample plots exactly in the field for glauconites. All these features indicate that the surface samples are strongly altered by weathering and that glauconite progressively

Characteristics and functions of semi-desert soils in the Negev (Israel) depending on precipitation, relief and vegetation

NASA Astrophysics Data System (ADS)

Felde, V.; Drahorad, S.; Felix-Henningsen, P.

2009-04-01

The Negev desert in south western Israel has been the subject of several investigations concerning soil forming processes and matter fluxes in desert soils. In order to investigate the influence of the ‘global change' on semi-desert ecosystems, study sites along a steep rainfall gradient are of great advantage. The study site "Nizzana 69", which is in the focus of this study, lies about 25 km south of the Mediterranean Sea near the border between Israel and Egypt. The area has an annual rainfall of approximately 170 mm * a-1. A catena consisting of six profiles, three under the legume Retama raetam and three in the bare interspace between shrubs was investigated in order to show the impact of this perennial plant and the relief on soil properties. The results show a strong influence of the shrub due to accumulation of nutrients, carbonates and soluble salts, which were precipitated with dust and rainfall, or which derive from mineralisation of plant litter. The interspace between the plants is covered by a biological soil crust, which also strongly influences the matter fluxes by creating runoff, nitrogen-fixation and stabilizing the soil surface and protecting it against deflation. The distribution of salts and carbonates in the profiles indicate leaching processes. All soils of the study site "Nizzana 69" are weekly developed Arenosols without horizons of carbonate or salt enrichment to a depth of 1 m. The comparison with other areas along the rainfall gradient shows higher inputs of soluble salts with increasing precipitation due to wet deposition, while carbonate contents increase with decreasing precipitation due to deposition of dust, which was generated in the lime stone Negev. On the other hand leaching of soluble soil constituents decreases and accumulation in the upper soil horizon increases with decreasing annual precipitation. Furthermore the importance of local relief aspects for plant growth decreases with increasing rainfall.

Anthropogenic wetlands due to over-irrigation of desert areas; A challenging hydrogeological investigation with extensive geophysical input

NASA Astrophysics Data System (ADS)

Behroozmand, A. A.; Teatini, P.; Pedersen, J. B. B.; Auken, E.; Tosatto, O.; Christiansen, A. V.

2015-12-01

During the last century, many large irrigation projects have been initiated in arid lands worldwide. Despite a tremendous increase in food production, a common problem when characterizing these zones is land degradation in form of waterlogging. As results, large volumes of water are lost due to surplus irrigation in regions where water availability is extremely challenging for both population survival and economic development. The Nubariya depression, Western Desert (Egypt), is a clear example of this mechanism. Following the reclamation of desert lands for agricultural production, an artificial brackish and contaminated lake developed in the area in the late 1990s and presently extends for about 2.5 km2. Available data provide evidence of a simultaneous general deterioration of the groundwater system. With the main objectives of understanding the hydrological evolution of the area, characterizing the hydrogeological setting and developing scenarios for artificial aquifer remediation and recharge, an extensive hydrogeophysical investigation was carried out in this challenging environment using Magnetic Resonance Sounding (MRS, also called surface NMR) and ground-based Transient EM (TEM). The integrated interpretation of the geophysical surveys, properly calibrated with a number of boreholes, provides a clear hydrogeological picture of the upper 100 m sedimentary structure, in terms of both lithology and groundwater quality. The information is then used to set up a regional groundwater flow and a local density-dependent flow and transport numerical model to reproduce the past evolution of the aquifer system and develop a few scenarios for artificial aquifer recharge using the treated waters provided by a nearby waste-water treatment plant. The research outcomes point the hydrological challenges that emerge for an effective management of water resources in reclaimed desert areas and highlight the effectiveness of integrating advanced geophysical and modeling

Investigation of geotechnical parameters from CSEM mapping and monitoring data at the oases Kharga and Baris of Sahara desert, Egypt

NASA Astrophysics Data System (ADS)

Hachay, Olga; Khachay, Oleg; Attia, Magdy; Khalil, Ahmed; Mekkawi, Mahmoud; Soliman, Mamdouh

2016-04-01

The site of investigation, oasis Kharga, is located at about 600 km south of Cairo, Egypt; Baris is about 90 km from Kharga also to south and towards more inside the desert. The work was aimed to investigate the rock mass stability at Baris and to estimate the water intake in the Oasis Kharga. A controlled source electromagnetic (CSEM) approach developed earlier by IGF UB RAS (Geophysical Federal Institute, Ural Branch of Russian Academy of Science) is applied to image the ranked deformation levels in the massive structure of the Baris. The wide profile system of observation has been used to monitor the three components of the alternating magnetic field along predefined measuring lines in the study area. Here we can show the first results that we shall continue during some cycles of monitoring. The second part of our work was linked with mapping the massif structure inside the oasis City, where only using our device we could construct the geoelectrical sections for 5 profiles and show the real structure of the water volume and its complicated structure up to 200 meters depth recording the values of real not apparent resistivity. The analytical treatments provided good information about the structure of the rock massive and its rank of degradation, the lateral distribution of the geotechnical heterogeneity, and finally a conclusive outcome about foundation stability. We can conclude that the general dynamic state close to the destruction level within the investigation areas is getting worse over the time; this is reflected in the crack's densities and positions, also on the changes in the lateral distribution of geoelectrical heterogeneity as an indicator of the saturation of the surface rock in the study area with water [1,2]. References 1. Magdy A. Atya, Olga A. Hachay, Mamdouh M. Soliman, Oleg Y. Khachay, Ahmed B. Khalill, Mahmoud Gaballah, Fathy F.Shaaban and Ibrahim A.El. Hemali. CSEM imaging of the near surface dynamics and its impact for foundation stability

Negev: Land, Water, and Life in a Desert Environment

NASA Astrophysics Data System (ADS)

Back, William

In view of the continuing increased concern about the extreme fragility of deserts and desert margins, Negev provides a timely discussion of land-use practices compatible with the often conflicting goals of preservation and development. The success o f agricultural and hydrologic experiments in the Negev desert of Israel offers hope to the large percentage of the world's population that lives with an unacceptably low quality of life in desert margins. Deserts are the one remaining type of open space that, with proper use, has the potential for alleviating the misery often associated with expanding population.In addition to the science in the book, the author repeatedly reinforces the concept that “western civilization is inextricably bound to the Negev and its environs, from which it has drawn, via its desert-born religions—Judasium, Christianity, and Islam—many of the mores and concepts, and much of the imagery and love of the desert, including man's relation to nature and to ‘God’.” Deserts often are erroneously perceived to be areas of no water: In reality, these are areas in which a little rainfall occurs sporadically and unpredictably over time. This meager water supply can be meticulously garnered to produce nutritious crops and forage.

Chronology of desert margin in western India using improved luminescence dating protocols

NASA Astrophysics Data System (ADS)

Chauhan, Naveen; Morthekai, P.

2017-12-01

The present study provides improved chronology for the desert margin fluvial sediments of semi-arid region located in the Mahi river basin, western India. The sequence has preserved a near-continuous record of climate change since the Last Interglacial. An earlier attempt of dating based on feldspar IRSL chronology shows a combined effect of anomalous fading and unbleached components resulting in age inversions. The present work tries to explore the possibility of using blue light stimulated luminescence (BLSL) of quartz, infra-red stimulated luminescence (IRSL) of feldspar and the newly developed methodologies, like natural correction factor based single aliquot regeneration (NCF-SAR) protocol and decision making schemes based on distribution of doses and beta heterogeneity concept for luminescence dating of sediments. Observations suggest that quartz suffered from significant sensitivity changes during natural signal measurement and partial bleaching. A combination of NCF-SAR protocol and sample specific equivalent dose computation helped in arriving at better age estimate for present samples. The study also compares the criteria for the selection of different age models that are used at present. The age of the alluvial sequence is now bracketed between 10 ka (upper aeolian unit) and 75 ka (lowermost fluvial unit).

Desert farming benefits from microbial potential in arid soils and promotes diversity and plant health.

PubMed

Köberl, Martina; Müller, Henry; Ramadan, Elshahat M; Berg, Gabriele

2011-01-01

To convert deserts into arable, green landscapes is a global vision, and desert farming is a strong growing area of agriculture world-wide. However, its effect on diversity of soil microbial communities, which are responsible for important ecosystem services like plant health, is still not known. We studied the impact of long-term agriculture on desert soil in one of the most prominent examples for organic desert farming in Sekem (Egypt). Using a polyphasic methodological approach to analyse microbial communities in soil as well as associated with cultivated plants, drastic effects caused by 30 years of agriculture were detected. Analysing bacterial fingerprints, we found statistically significant differences between agricultural and native desert soil of about 60%. A pyrosequencing-based analysis of the 16S rRNA gene regions showed higher diversity in agricultural than in desert soil (Shannon diversity indices: 11.21/7.90), and displayed structural differences. The proportion of Firmicutes in field soil was significantly higher (37%) than in the desert (11%). Bacillus and Paenibacillus play the key role: they represented 96% of the antagonists towards phytopathogens, and identical 16S rRNA sequences in the amplicon library and for isolates were detected. The proportion of antagonistic strains was doubled in field in comparison to desert soil (21.6%/12.4%); disease-suppressive bacteria were especially enriched in plant roots. On the opposite, several extremophilic bacterial groups, e.g., Acidimicrobium, Rubellimicrobium and Deinococcus-Thermus, disappeared from soil after agricultural use. The N-fixing Herbaspirillum group only occurred in desert soil. Soil bacterial communities were strongly driven by the a-biotic factors water supply and pH. After long-term farming, a drastic shift in the bacterial communities in desert soil was observed. Bacterial communities in agricultural soil showed a higher diversity and a better ecosystem function for plant health but a

Desert Farming Benefits from Microbial Potential in Arid Soils and Promotes Diversity and Plant Health

PubMed Central

Köberl, Martina; Müller, Henry; Ramadan, Elshahat M.; Berg, Gabriele

2011-01-01

Background To convert deserts into arable, green landscapes is a global vision, and desert farming is a strong growing area of agriculture world-wide. However, its effect on diversity of soil microbial communities, which are responsible for important ecosystem services like plant health, is still not known. Methodology/Principal Findings We studied the impact of long-term agriculture on desert soil in one of the most prominent examples for organic desert farming in Sekem (Egypt). Using a polyphasic methodological approach to analyse microbial communities in soil as well as associated with cultivated plants, drastic effects caused by 30 years of agriculture were detected. Analysing bacterial fingerprints, we found statistically significant differences between agricultural and native desert soil of about 60%. A pyrosequencing-based analysis of the 16S rRNA gene regions showed higher diversity in agricultural than in desert soil (Shannon diversity indices: 11.21/7.90), and displayed structural differences. The proportion of Firmicutes in field soil was significantly higher (37%) than in the desert (11%). Bacillus and Paenibacillus play the key role: they represented 96% of the antagonists towards phytopathogens, and identical 16S rRNA sequences in the amplicon library and for isolates were detected. The proportion of antagonistic strains was doubled in field in comparison to desert soil (21.6%/12.4%); disease-suppressive bacteria were especially enriched in plant roots. On the opposite, several extremophilic bacterial groups, e.g., Acidimicrobium, Rubellimicrobium and Deinococcus-Thermus, disappeared from soil after agricultural use. The N-fixing Herbaspirillum group only occurred in desert soil. Soil bacterial communities were strongly driven by the a-biotic factors water supply and pH. Conclusions/Significance After long-term farming, a drastic shift in the bacterial communities in desert soil was observed. Bacterial communities in agricultural soil showed a higher

Carbonate-orthopyroxenite lenses from the Neoproterozoic Gerf ophiolite, South Eastern Desert, Egypt: The first record in the Arabian Nubian Shield ophiolites

NASA Astrophysics Data System (ADS)

Gahlan, Hisham A.; Arai, Shoji

2009-01-01

Carbonate-orthopyroxenites (classic sagvandites) are reported in the Gerf ophiolite, South Eastern Desert, Egypt: the first finding from the Arabian Nubian Shield (ANS) ophiolites. They form massive lenses at the southern tip of the Gerf ophiolite, along the contact between the Shinai granite and Gerf serpentinized peridotites. The lenses show structural concordance with the neighboring country rocks and the granite contact. They consist mainly of metamorphic orthopyroxene + magnesite, among other metamorphic, relict primary and retrograde secondary minerals. Based only on chemistry, two types of carbonate-orthopyroxenites can be recognized, Types I (higher-Mg) and II (lower-Mg and higher-Fe). Field constraints, petrography and mineral chemistry indicate a metamorphic origin for the Gerf carbonate-orthopyroxenites. The euhedral form of relict primary chromian spinels combined with their high Cr#/low-TiO 2 character, and absence of clinopyroxene suggest that the protolith for the Gerf carbonate-orthopyroxenites is a highly depleted mantle peridotite derived from a sub-arc setting. Contact metamorphism accompanied by CO 2-metasomatism resulted in formation of the Gerf carbonate-orthopyroxenites during intrusion of the Shinai granite. The source of CO 2-rich fluids is most likely the neighboring impure carbonate layers. Correlation of the carbonate-orthopyroxenite mineral assemblages with experimental data for the system MgO-SiO 2-H 2O-CO 2 suggests metamorphic/metasomatic conditions of 520-560 °C, Pfluid = 2 kbar and extremely high X values (0.87-1).

Geoelectrical contribution for delineation the groundwater potential and subsurface structures on Tushka Area, Egypt

NASA Astrophysics Data System (ADS)

Abd El-Gawad, A. M. S.; Kotb, Adel D. M.; Hussien, Galal H. G.

2017-12-01

Tushka area represents the South East Western Desert, Egypt. its contain many drilled wells which have many problems during use, so the present study aims at identify the aquifer conditions and its relation with surface water and subsurface structure in addition to determine the aquifer thickness by using the basement relief from previous work, then assess the current situation of the drilled water wells. Geoelectrical data were measured, processed and interpreted in one, two and three dimensions using special Equipments and software. The interpretation results demonstrated that two types of groundwater aquifers (confined and unconfined) are present in the study area. The confined aquifer is located at the south of Khor Tushka and the unconfined aquifer is found in the north of Khor Tushka, where the last one is charged from Lake Nasser and Khor Tushka. The groundwater aquifers thicknesses are up to 440 m and the area is affected by normal faults of NW-SE and NE-SW trends. The study showed that there is no connection between the confined aquifer and the shallow overlaying aquifer. The confined aquifer is charged partially from the lake Nasser and Khor Tushka through specific areas under the capping layers of Nubian sandstone filled with hydrothermal solution and shale.

Nonlinear spectral mixture effects for photosynthetic/non-photosynthetic vegetation cover estimates of typical desert vegetation in western China.

PubMed

Ji, Cuicui; Jia, Yonghong; Gao, Zhihai; Wei, Huaidong; Li, Xiaosong

2017-01-01

Desert vegetation plays significant roles in securing the ecological integrity of oasis ecosystems in western China. Timely monitoring of photosynthetic/non-photosynthetic desert vegetation cover is necessary to guide management practices on land desertification and research into the mechanisms driving vegetation recession. In this study, nonlinear spectral mixture effects for photosynthetic/non-photosynthetic vegetation cover estimates are investigated through comparing the performance of linear and nonlinear spectral mixture models with different endmembers applied to field spectral measurements of two types of typical desert vegetation, namely, Nitraria shrubs and Haloxylon. The main results were as follows. (1) The correct selection of endmembers is important for improving the accuracy of vegetation cover estimates, and in particular, shadow endmembers cannot be neglected. (2) For both the Nitraria shrubs and Haloxylon, the Kernel-based Nonlinear Spectral Mixture Model (KNSMM) with nonlinear parameters was the best unmixing model. In consideration of the computational complexity and accuracy requirements, the Linear Spectral Mixture Model (LSMM) could be adopted for Nitraria shrubs plots, but this will result in significant errors for the Haloxylon plots since the nonlinear spectral mixture effects were more obvious for this vegetation type. (3) The vegetation canopy structure (planophile or erectophile) determines the strength of the nonlinear spectral mixture effects. Therefore, no matter for Nitraria shrubs or Haloxylon, the non-linear spectral mixing effects between the photosynthetic / non-photosynthetic vegetation and the bare soil do exist, and its strength is dependent on the three-dimensional structure of the vegetation canopy. The choice of linear or nonlinear spectral mixture models is up to the consideration of computational complexity and the accuracy requirement.

Nonlinear spectral mixture effects for photosynthetic/non-photosynthetic vegetation cover estimates of typical desert vegetation in western China

PubMed Central

Jia, Yonghong; Gao, Zhihai; Wei, Huaidong

2017-01-01

Desert vegetation plays significant roles in securing the ecological integrity of oasis ecosystems in western China. Timely monitoring of photosynthetic/non-photosynthetic desert vegetation cover is necessary to guide management practices on land desertification and research into the mechanisms driving vegetation recession. In this study, nonlinear spectral mixture effects for photosynthetic/non-photosynthetic vegetation cover estimates are investigated through comparing the performance of linear and nonlinear spectral mixture models with different endmembers applied to field spectral measurements of two types of typical desert vegetation, namely, Nitraria shrubs and Haloxylon. The main results were as follows. (1) The correct selection of endmembers is important for improving the accuracy of vegetation cover estimates, and in particular, shadow endmembers cannot be neglected. (2) For both the Nitraria shrubs and Haloxylon, the Kernel-based Nonlinear Spectral Mixture Model (KNSMM) with nonlinear parameters was the best unmixing model. In consideration of the computational complexity and accuracy requirements, the Linear Spectral Mixture Model (LSMM) could be adopted for Nitraria shrubs plots, but this will result in significant errors for the Haloxylon plots since the nonlinear spectral mixture effects were more obvious for this vegetation type. (3) The vegetation canopy structure (planophile or erectophile) determines the strength of the nonlinear spectral mixture effects. Therefore, no matter for Nitraria shrubs or Haloxylon, the non-linear spectral mixing effects between the photosynthetic / non-photosynthetic vegetation and the bare soil do exist, and its strength is dependent on the three-dimensional structure of the vegetation canopy. The choice of linear or nonlinear spectral mixture models is up to the consideration of computational complexity and the accuracy requirement. PMID:29240777

Introduction to the special issue on the changing Mojave Desert

USGS Publications Warehouse

Berry, Kristin H.; Murphy, R.W.; Mack, Jeremy S.; Quillman, W.

2006-01-01

The Mojave Desert, which lies between the Great Basin Desert in the north and the Sonoran Desert in the south, covers an estimated 114 478–130 464 km2 of the south-western United States and includes parts of the states of Nevada, Utah, Arizona, and California, with the amount of land mass dependent on the definition (Fig. 1; Rowlands et al., 1982; McNab and Avers, 1994; Bailey, 1995; Groves et al., 2000). This desert is sufficiently diverse to be subdivided into five regions: northern, south-western, central, south-central, and eastern (Rowlands et al., 1982). It is a land of extremes both in topography and climate. Elevations range from below sea level at Death Valley National Park to 3633 m on Mt. Charleston in the Spring Range of Nevada. Temperatures exhibit similar extreme ranges with mean minimum January temperatures of −2.4 °C in Beatty, Nevada and mean maximum July temperatures of 47 °C in Death Valley. Mean annual precipitation varies throughout the regions (42–350 mm), is highest on mountain tops, but overall is low (Rowlands et al., 1982; Rowlands, 1995a). The distribution of precipitation varies from west to east and north to south, with >85% of rain falling in winter in the northern, south-western and south-central regions. In contrast, the central and eastern regions receive a substantial amount of precipitation in both winter and summer. The variability in topographic and climatic features contributes to regional differences in vegetation.

Cold desert fire and invasive species management: Resources, strategies, tactics, and response

Treesearch

Jeanne C. Chambers; Elizabeth Leger; Erin Goergen

2009-01-01

The cold desert of North America, sometimes referred to as the Intermountain area, is comprised of a western Great Basin section and an eastern Colorado Plateau section. In general, the cold desert receives more than half of its annual precipitation as snow, and because of its more northern latitude or higher elevations, has relatively low average annual temperatures....

Trace elements assessment in agricultural and desert soils of Aswan area, south Egypt: Geochemical characteristics and environmental impacts

NASA Astrophysics Data System (ADS)

Darwish, Mohamed Abdallah Gad; Pöllmann, Hebert

2015-12-01

Determination of chemical elements, Al, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, P, Pb, Sc, Sr, Ti, Y, and Zn have been performed in agricultural and desert soils and alfalfa (Medicago sativa) at Aswan area. Consequently, the pollution indices, univariate and multivariate statistical methods have been applied, in order to assess the geochemical characteristics of these elements and their impact on soil environmental quality and plant, and to reach for their potential input sources. The investigation revealed that the mean and range values of all element concentrations in agricultural soil are higher than those in desert soil. Furthermore, the agricultural soil displayed various degrees of enrichment and pollution of Cd, Zn, Mo, Co, P, Ti, Pb. The geochemical pattern of integrated pollution indices gave a clear image of extreme and strong pollution in the agricultural soil stations, their poor quality with high risk to human health and considered as a tocsin for an alert. In contrast, the desert soil is the good environmental quality and safe for plant, animal and human health. Alfalfa is tolerant plant and considered as a biomarker for P and Mo in polluted agricultural soil. Four geochemical associations of analyzing elements in agricultural soil and three ones in desert soil have been generated, and their enhancements were essentially caused by various anthropogenic activities and geogenic sources. The investigation also revealed that the broad extended desert soil is fruitful and promising as cultivable lands for agricultural processes in the futures.

Deserts

USGS Publications Warehouse

Belnap, Jayne; Webb, Robert H.; Esque, Todd; Brooks, Matthew L.; DeFalco, Lesley; MacMahon, James A.

2016-01-01

The deserts of California (Lead photo, Fig. 1) occupy approximately 38% of California’s landscape (Table 1) and consist of three distinct deserts: the Great Basin Desert, Mojave Desert, and Colorado Desert, the latter of which is a subdivision of the Sonoran Desert (Brown and Lowe 1980). The wide range of climates and geology found within each of these deserts result in very different vegetative communities and ecosystem processes and therefore different ecosystem services. In deserts, extreme conditions such as very high and low temperatures and very low rainfall result in abiotic factors (climate, geology, geomorphology, and soils) controlling the composition and function of ecosystems, including plant and animal distributions. This is in contrast to wetter and milder temperatures found in other ecosystems, where biotic interactions are the dominant driving force. However, despite the harsh conditions in deserts, they are home to a surprisingly large number of plants and animals. Deserts are also places where organisms display a wide array of adaptations to the extremes they encounter, providing some of the best examples of Darwinian selection (MacMahon and Wagner 1985, Ward 2009). Humans have utilized these regions for thousands of years, despite the relatively low productivity and harsh climates of these landscapes. Unlike much of California, most of these desert lands have received little high-intensity use since European settlement, leaving large areas relatively undisturbed. Desert landscapes are being altered, however, by the introduction of fire following the recent invasion of Mediterranean annual grasses. As most native plants are not fire-adapted, they Many do not recover, whereas the non-native grasses flourish. Because desert lands are slow to recover from disturbances, energy exploration and development, recreational use, and urban development will alter these landscapes for many years to come. This chapter provides a brief description of where the

Variations in water balance and recharge potential at three western desert sites

USGS Publications Warehouse

Gee, G.W.; Wierenga, P.J.; Andraski, Brian J.; Young, M.H.; Fayer, M.J.; Rockhold, M.L.

1994-01-01

Radioactive and hazardous waste landfills exist at numerous desert locations in the USA. At these locations, annual precipitation is low and soils are generally dry, yet little is known about recharge of water and transport of contaminants to the water table. Recent water balance measurements made at three desert locations, Las Cruces, NM, Beatty, NV, and the U.S. Department of Energy's Hanford Site in the state of Washington, provide information on recharge potential under three distinctly different climate and soil conditions. All three sites show water storage increases with time when soils are coarse textured and plants are removed from the surface, the rate of increase being influenced by climatic variables such as precipitation, radiation, temperature, and wind. Lysimeter data from Hanford and Las Cruces indicate that deep drainage (recharge) from bare, sandy soils can range from 10 to >50% of the annual precipitation. At Hanford, when desert plants are present on sandy or gravelly surface soils, deep drainage is reduced but not eliminated. When surface soils are silt loams, deep drainage is eliminated whether plants are present or not. At Las Cruces and Beatty, the presence of plants eliminated deep drainage at the measurement sites. Differences in water balance between sites are attributed to precipitation quantity and distribution and to soil and vegetation types. The implication for waste management at desert locations is that surface soil properties and plant characteristics must be considered in waste site design in order to minimize recharge potential.

Anthropogenic wetlands due to over-irrigation of desert areas: a challenging hydrogeological investigation with extensive geophysical input from TEM and MRS measurements

NASA Astrophysics Data System (ADS)

Behroozmand, Ahmad Ali; Teatini, Pietro; Bjergsted Pedersen, Jesper; Auken, Esben; Tosatto, Omar; Vest Christiansen, Anders

2017-03-01

During the last century, many large irrigation projects were carried out in arid lands worldwide. Despite a tremendous increase in food production, a common problem when characterizing these zones is land degradation in the form of waterlogging. A clear example of this phenomenon is in the Nubariya depression in the Western Desert of Egypt. Following the reclamation of desert lands for agricultural production, an artificial brackish and contaminated pond started to develop in the late 1990s, which at present extends for about 2.5 km2. The available data provide evidence of a simultaneous general deterioration of the groundwater system. An extensive hydrogeophysical investigation was carried out in this challenging environment using magnetic resonance sounding (MRS) and ground-based time-domain electromagnetic (TEM) techniques with the following main objectives: (1) understanding the hydrological evolution of the area; (2) characterizing the hydrogeological setting; and (3) developing scenarios for artificial aquifer remediation and recharge. The integrated interpretation of the geophysical surveys provided a hydrogeological picture of the upper 100 m sedimentary setting in terms of both lithological distribution and groundwater quality. The information is then used to set up (1) a regional groundwater flow and (2) a local density-dependent flow and transport numerical model to reproduce the evolution of the aquifer system and develop a few scenarios for artificial aquifer recharge using the treated water provided by a nearby wastewater treatment plant. The research outcomes point to the hydrological challenges that emerge for the effective management of water resources in reclaimed desert areas, and they highlight the effectiveness of using advanced geophysical and modeling methodologies.

Application of kinematic vorticity and gold mineralization for the wall rock alterations of shear zone at Dungash gold mining, Central Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

Kassem, Osama M. K.; Abd El Rahim, Said H.; El Nashar, EL Said R.; AL Kahtany, Kaled M.

2016-11-01

The use of porphyroclasts rotating in a flowing matrix to estimate mean kinematic vorticity number (Wm) is important for quantifying the relative contributions of pure and simple shear in wall rocks alterations of shear zone at Dungash gold mine. Furthermore, it shows the relationship between the gold mineralization and deformation and also detects the orientation of rigid objects during progressive deformation. The Dungash gold mine area is situated in an EW-trending quartz vein along a shear zone in metavolcanic and metasedimentary host rocks in the Eastern Desert of Egypt. These rocks are associated with the major geologic structures which are attributed to various deformational stages of the Neoproterozoic basement rocks. We conclude that finite strain in the deformed rocks is of the same order of magnitude for all units of metavolcano-sedimentary rocks. The kinematic vorticity number for the metavolcanic and metasedimentary samples in the Dungash area range from 0.80 to 0.92, and together with the strain data suggest deviations from simple shear. It is concluded that nappe stacking occurred early during the underthrusting event probably by brittle imbrication and that ductile strain was superimposed on the nappe structure during thrusting. Furthermore, we conclude that disseminated mineralization, chloritization, carbonatization and silicification of the wall rocks are associated with fluids migrating along shearing, fracturing and foliation of the metamorphosed wall rocks.

Hydrogeochemical analysis and evaluation of groundwater in the reclaimed small basin of Abu Mina, Egypt

NASA Astrophysics Data System (ADS)

Salem, Zenhom E.; Atwia, Mohamed G.; El-Horiny, Mohamed M.

2015-12-01

Agricultural reclamation activities during the last few decades in the Western Nile Delta have led to great changes in the groundwater levels and quality. In Egypt, changing the desert land into agricultural land has been done using transferred Nile water (through irrigation canal systems) or/and groundwater. This research investigates the hydrogeochemical changes accompanying the reclamation processes in the small basin of Abu Mina, which is part of the Western Nile Delta region. In summer 2008, 23 groundwater samples were collected and groundwater levels were measured in 40 observation wells. Comparing the groundwater data of the pre-reclamation (1974) and the post-reclamation (2008) periods, groundwater seems to have been subjected to many changes: rise in water level, modification of the flow system, improvement of water quality, and addition of new salts through dissolution processes. Generally, Abu Mina basin is subdivided into two areas, recharge and discharge. The dissolution and mixing were recognized in the recharge areas, while the groundwater of the discharge region carries the signature of the diluted pre-reclamation groundwater. The salts of soil and aquifer deposits play an important role in the salt content of the post and pre-reclamation groundwater. NaCl was the predominant water type in the pre-reclamation groundwater, while CaSO4, NaCl and MgSO4 are the common chemical facies in the post-reclamation groundwater. The post-reclamation groundwater mostly indicates mixing between the pre-reclamation groundwater and the infiltrated freshwater with addition of some ions due to interaction with soil and sediments.

Proterozoic deformation of the East Saharan Craton in Southeast Libya, South Egypt and North Sudan

NASA Astrophysics Data System (ADS)

Schandelmeier, H.; Richter, A.; Harms, U.

1987-09-01

The basement areas in Southeast Libya, South Egypt and North Sudan, west of the Nile, between Gebel Uweinat and the Bayuda Desert, are part of an approximately 1000-km-wide, complexly folded, polymetamorphic zone with a regional N-NNE-NE-ENE trend of foliation and fold axis. Since this belt extends southwestward into the area of Zalingei in the southern Darfur block (West Sudan), it is named the Northern Zalingei fold zone. Sr and Nd isotopic studies suggest that this zone is older than Pan-African and further indicate that, apart from Archean rocks in the Gebel Uweinat area, this belt is of Early-Middle Proterozoic age. An Early-Middle Proterozoic three-stage deformational and anatectic event established the present-day fold and fault geometry in the western parts of this zone in the Gebel Uweinat—Gebel Kamil area. The Pan-African tectono-thermal episode was most effective in the eastern part of the belt, near the boundary with the Nubian Shield volcano-sedimentary-ophiolite-granitoid assemblages. It caused migmatization, granite emplacement, mylonitization and large-scale wrench faulting which was related to Late Proterozoic accretionary and collisional events of the Arabian-Nubian Shield with the margin of the East Saharan Craton.

Geochemical and K Ar age constraints on the Late Neoproterozoic (?) gneisses at Um Tenassib area, north Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

Eliwa, Hassan A.

2007-05-01

been contemporaneous with the suggested regional metamorphism at 620 ± 10 Ma for Sinai metamorphic rocks (Cosca et al., 1999) and/or the emplacement age at 614 Ma for the granodiorite in the study area [Stern, R.J., Hedge, C.E., 1985. Geochronological and isotopic constraints on the Late Precambrian crustal evolution in the Eastern Desert of Egypt. Am. J. Sci. 285, 97-127]. These ages also lie within the range of magmatic activity of the Younger Granites in the North Eastern Desert (575-600 Ma).

Ion beam analysis studies of desert varnish

NASA Astrophysics Data System (ADS)

Duerden, P.; Cohen, D. D.; Dragovich, D.; Clayton, E.

1986-04-01

The components of "desert varnish" cover on rock surfaces from western New South Wales have been investigated by a number of ion beam techniques. The elemental data obtained so far show significant changes in composition of F, Na, K, Ti, Ba and Mn when varnish is present on the rock surface.

Concentrations of mineral aerosol from desert to plains across the central Rocky Mountains, western United States

NASA Astrophysics Data System (ADS)

Reynolds, Richard L.; Munson, Seth M.; Fernandez, Daniel; Goldstein, Harland L.; Neff, Jason C.

2016-12-01

Mineral dusts can have profound effects on climate, clouds, ecosystem processes, and human health. Because regional dust emission and deposition in western North America are not well understood, measurements of total suspended particulate (TSP) from 2011 to 2013 were made along a 500-km transect of five remote sites in Utah and Colorado, USA. The TSP concentrations in μg m-3 adjusted to a 24-h period were relatively high at the two westernmost, dryland sites at Canyonlands National Park (mean = 135) and at Mesa Verde National Park (mean = 99), as well as at the easternmost site on the Great Plains (mean = 143). The TSP concentrations at the two intervening montane sites were less, with more loading on the western slope of the Rocky Mountains (Telluride, mean = 68) closest to the desert sites compared with the site on the eastern slope (Niwot Ridge, mean = 58). Dust concentrations were commonly highest during late winter-late spring, when Pacific frontal storms are the dominant causes of regional wind. Low concentrations (<7 wt%) of organic matter indicated that rock-derived mineral particles composed most TSP. Most TSP mass was carried by particle sizes larger than 10 μm (PM>10), as revealed by relatively low average daily concentrations of fine (<5 μg m-3; PM2.5) and coarse (<10 μg m-3; PM2.5-10) fractions monitored at or near four sites. Standard air-quality measurements for PM2.5 and PM10 apparently do not capture the large majority of mineral-particulate pollution in the remote western interior U.S.

Desert Dermatoses (Thar Desert, India).

PubMed

Chatterjee, Col Manas

2017-01-01

Desert dermatology describes the cutaneous changes and the diseases affecting those living in the desert. Diurnal variation in temperature is high and is characteristic of the deserts. The lack of water affects daily activities and impacts dermatological conditions. Adaptation to the desert is, therefore, important to survival. Infections are the most common conditions seen among this population, and among them, fungal infections are the most common. The high incidence of these infections would be accounted for by the poor hygienic conditions due to lack of bathing facilities due to scarcity of water and the consequent sweat retention and overgrowth of cutaneous infective organisms. Pigmentary disorders, photodermatoses, leishmaniasis, and skin tumors are found to be more prevalent in this region. Desert sweat dermatitis was another specific condition found to have an increased incidence. The environment of the desert provides for a wide variety of dermatoses that can result in these regions with few of these dermatoses found in much higher incidence than in other regions.

Desert Dermatoses (Thar Desert, India)

PubMed Central

Chatterjee, Col Manas

2017-01-01

Desert dermatology describes the cutaneous changes and the diseases affecting those living in the desert. Diurnal variation in temperature is high and is characteristic of the deserts. The lack of water affects daily activities and impacts dermatological conditions. Adaptation to the desert is, therefore, important to survival. Infections are the most common conditions seen among this population, and among them, fungal infections are the most common. The high incidence of these infections would be accounted for by the poor hygienic conditions due to lack of bathing facilities due to scarcity of water and the consequent sweat retention and overgrowth of cutaneous infective organisms. Pigmentary disorders, photodermatoses, leishmaniasis, and skin tumors are found to be more prevalent in this region. Desert sweat dermatitis was another specific condition found to have an increased incidence. The environment of the desert provides for a wide variety of dermatoses that can result in these regions with few of these dermatoses found in much higher incidence than in other regions. PMID:28216726

Texture analysis of aeromagnetic data for enhancing geologic features using co-occurrence matrices in Elallaqi area, South Eastern Desert of Egypt

NASA Astrophysics Data System (ADS)

Eldosouky, Ahmed M.; Elkhateeb, Sayed O.

2018-06-01

Enhancement of aeromagnetic data for qualitative purposes depends on the variations of texture and amplitude to outline various geologic features within the data. The texture of aeromagnetic data consists continuity of adjacent anomalies, size, and pattern. Variations in geology, or particularly rock magnetization, in a study area cause fluctuations in texture. In the present study, the anomalous features of Elallaqi area were extracted from aeromagnetic data. In order to delineate textures from the aeromagnetic data, the Red, Green, and Blue Co-occurrence Matrices (RGBCM) were applied to the reduced to the pole (RTP) grid of Elallaqi district in the South Eastern Desert of Egypt. The RGBCM are fashioned of sets of spatial analytical parameters that transform magnetic data into texture forms. Six texture features (parameters), i.e. Correlation, Contrast, Entropy, Homogeneity, Second Moment, and Variance, of RGB Co-occurrence Matrices (RGBCM) are used for analyzing the texture of the RTP grid in this study. These six RGBCM texture characteristics were mixed into a single image using principal component analysis. The calculated texture images present geologic characteristics and structures with much greater sidelong resolution than the original RTP grid. The estimated texture images enabled us to distinguish multiple geologic regions and structures within Elallaqi area including geologic terranes, lithologic boundaries, cracks, and faults. The faults of RGBCM maps were more represented than those of magnetic derivatives providing enhancement of the fine structures of Elallaqi area like the NE direction which scattered WNW metavolcanics and metasediments trending in the northwestern division of Elallaqi area.

Regional and Seasonal Diet of the Western Burrowing Owl in South-Central Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Derek B. Hall, Paul D. Greger, Jeffrey R. Rosier

2009-04-01

We examined diets of Western Burrowing Owls (Athene cunicularia hypugaea) based on contents of pellets and large prey remains collected year-round at burrows in each of the 3 regions in south central Nevada (Mojave Desert, Great Basin Desert, and Transition region). The most common prey items, based on percent frequency of occurrence, were crickets and grasshoppers, beetles, rodents, sun spiders, and scorpions. The most common vertebrate prey was kangaroo rats (Dipodomys spp.). True bugs (Hemiptera), scorpions, and western harvest mice (Reithrodontomys megalotis) occurred most frequently in pellets from the Great Basin Desert region. Kangaroo rats (Dipodomys spp.) and pocket micemore » (Perognathinae) were the most important vertebrate prey items in the Transition and Mojave Desert regions, respectively. Frequency of occurrence of any invertebrate prey was high (>80%) in samples year-round but dropped in winter samples, with scorpions and sun spiders exhibiting the steepest declines. Frequency of occurrence of any vertebrate prey peaked in spring samples, was intermediate for winter and summer samples, and was lowest in fall samples. With the possible exception of selecting for western harvest mice in the Great Basin Desert region, Western Burrowing Owls in our study appeared to be opportunistic foragers with a generalist feeding strategy.« less

Study of atmospheric scattering and absorbing aerosols at 550 nm over nearby western Indian tropical sites of Thar Desert effected region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vyas, B. M., E-mail: bmvyas@yahoo.com; Saxenna, Abhishek; Panwar, Chhagan

The first time experimental results based on spaced satellite observations of different kinds of aerosols properties have been described over two different contrast environmental conditions locations in western tropical Indian region specifically first at Jaisalmer (26.90°N, 69.90°E, 220 m above mean sea level (amsl)) located in central Thar dessert vicinity of western Indian site over Indian Thar Desert region and another at Udaipur (24.6° N, 73.7° E, 560 m amsl) site concerning to semi-urban and semi arid place of hilly areas. The daily values of aerosols optical depth absorption at 500nm (AOD abs 500nm), aerosols optical depth extinction at 500nmmore » (AOD ext 500nm) along with aerosols optical depth at 500nmon (AOD 500nm) of eleven year period from Jan., 2004 to Dec., 2014 are basis of primary database of the present investigation. From the synthesis if the above database and the basis of rigorous statistical approach, following some of interesting facts are noted (i) larger annual monthly AOD variation of 0.93 is noted over JSM when compared to observed annual monthly change in AOD cycle, over UDP, of only 0.50 clearly indicating the more impact of desert influence activities about more than double times over JSM than UDP (ii) The higher abundance of absorbing aerosols occurrences about two time higher are seen in JSM in comparison to UDP. It indicates the clear evidence of strong optical absorption properties of useful solar mid visible wavelength at 550nm as the results of presence of more availability of dust aerosols as mineral natural type in pre-monsoon to post-monsoon over JSM which is also more predominant over JSM than the UDP region located far away from desert activity regime (iii) The greater sharing of extinction solar radiation effect on aerosols are more effective in pre-monsoon in UDP in reference to over JSM, where as in case of UDP, the aerosols effect through the scattering mechanism gradually reduce from monsoon to winter months as

Space Radar Image of Giza Egypt - with enlargement

NASA Technical Reports Server (NTRS)

1994-01-01

This radar image shows the area west of the Nile River near Cairo, Egypt. The Nile River is the dark band along the right side of the image and it flows approximately due North from the bottom to the right. The boundary between dense urbanization and the desert can be clearly seen between the bright and dark areas in the center of the image. This boundary represents the approximate extent of yearly Nile flooding which played an important part in determining where people lived in ancient Egypt. This land usage pattern persists to this day. The pyramids at Giza appear as three bright triangles aligned with the image top just at the boundary of the urbanized area. They are also shown enlarged in the inset box in the top left of the image. The Great Pyramid of Khufu (Cheops in Greek) is the northern most of the three Giza pyramids. The side-looking radar illuminates the scene from the top, the two sides of the pyramids facing the radar reflect most of the energy back to the antenna and appear radar bright; the two sides away from the radar reflect less energy back and appear dark Two additional pyramids can be seen left of center in the lower portion of the image. The modern development in the desert on the left side of the image is the Sixth of October City, an area of factories and residences started by Anwar Sadat to relieve urban crowding. The image was taken on April 19, 1994 by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and the United States space agencies, is part of NASA's Mission to Planet Earth. The image is centered on latitude 29.72 degrees North latitude and 30.83 degrees East longitude. The area shown is approximately 20 kilometers by 30 kilometers. The colors in the image are assigned to different frequencies and polarizations of the radar as follows: red is L-band horizontally transmitted, horizontally received; green is C

Space Radar Image of Giza Egypt - with Enlargement

NASA Image and Video Library

1999-04-15

This radar image shows the area west of the Nile River near Cairo, Egypt. The Nile River is the dark band along the right side of the image and it flows approximately due North from the bottom to the right. The boundary between dense urbanization and the desert can be clearly seen between the bright and dark areas in the center of the image. This boundary represents the approximate extent of yearly Nile flooding which played an important part in determining where people lived in ancient Egypt. This land usage pattern persists to this day. The pyramids at Giza appear as three bright triangles aligned with the image top just at the boundary of the urbanized area. They are also shown enlarged in the inset box in the top left of the image. The Great Pyramid of Khufu (Cheops in Greek) is the northern most of the three Giza pyramids. The side-looking radar illuminates the scene from the top, the two sides of the pyramids facing the radar reflect most of the energy back to the antenna and appear radar bright; the two sides away from the radar reflect less energy back and appear dark Two additional pyramids can be seen left of center in the lower portion of the image. The modern development in the desert on the left side of the image is the Sixth of October City, an area of factories and residences started by Anwar Sadat to relieve urban crowding. The image was taken on April 19, 1994 by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the shuttle Endeavour. SIR-C/X-SAR, a joint mission of the German, Italian and the United States space agencies, is part of NASA's Mission to Planet Earth. The image is centered on latitude 29.72 degrees North latitude and 30.83 degrees East longitude. The area shown is approximately 20 kilometers by 30 kilometers. The colors in the image are assigned to different frequencies and polarizations of the radar as follows: red is L-band horizontally transmitted, horizontally received; green is C

Integrated geoelectrical survey for groundwater and shallow subsurface evaluation: case study at Siliyin spring, El-Fayoum, Egypt

NASA Astrophysics Data System (ADS)

Metwaly, Mohamed; El-Qady, Gad; Massoud, Usama; El-Kenawy, Abeer; Matsushima, Jun; Al-Arifi, Nasser

2010-09-01

Siliyin spring is one of the many natural fresh water springs in the Western Desert of Egypt. It is located at the central part of El-Fayoum Delta, which is a potential place for urban developments and touristic activities. Integrated geoelectrical survey was conducted to facilitate mapping the groundwater resources and the shallow subsurface structures in the area. Twenty-eight transient electromagnetic (TEM) soundings, three vertical electrical soundings (VES) and three electrical resistivity tomography (ERT) profiles were carried out around the Siliyin spring location. The dense cultivation, the rugged topography and the existence of infra structure in the area hindered acquiring more data. The TEM data were inverted jointly with the VES and ERT, and constrained by available geological information. Based on the inversion results, a set of geoelectrical cross-sections have been constructed. The shallow sand to sandy clay layer that forms the shallow aquifer has been completely mapped underneath and around the spring area. Flowing of water from the Siliyin spring is interconnected with the lateral lithological changes from clay to sand soil. Exploration of the extension of Siliyin spring zone is recommended. The interpretation emphasizes the importance of integrating the geoelectrical survey with the available geological information to obtain useful, cheap and fast lithological and structural subsurface information.

Resistivity method contribution in determining of fault zone and hydro-geophysical characteristics of carbonate aquifer, eastern desert, Egypt

NASA Astrophysics Data System (ADS)

Ammar, A. I.; Kamal, K. A.

2018-03-01

Determination of fault zone and hydro-geophysical characteristics of the fractured aquifers are complicated, because their fractures are controlled by different factors. Therefore, 60 VESs were carried out as well as 17 productive wells for determining the locations of the fault zones and the characteristics of the carbonate aquifer at the eastern desert, Egypt. The general curve type of the recorded rock units was QKH. These curves were used in delineating the zones of faults according to the application of the new assumptions. The main aquifer was included at end of the K-curve type and front of the H-curve type. The subsurface layers classified into seven different geoelectric layers. The fractured shaly limestone and fractured limestone layers were the main aquifer and their resistivity changed from low to medium (11-93 Ω m). The hydro-geophysical properties of this aquifer such as the areas of very high, high, and intermediate fracture densities of high groundwater accumulations, salinity, shale content, porosity distribution, and recharging and flowing of groundwater were determined. The statistical analysis appeared that depending of aquifer resistivity on the water salinities (T.D.S.) and water resistivities add to the fracture density and shale content. The T.D.S. increasing were controlled by Na+, Cl-, Ca2+, Mg2+, and then (SO4)2-, respectively. The porosity was calculated and its average value was 19%. The hydrochemical analysis of groundwater appeared that its type was brackish and the arrangements of cation concentrations were Na+ > Ca2+ > Mg2+ > K+ and anion concentrations were Cl- > (SO4)2- > HCO3 - > CO3 -. The groundwater was characterized by sodium-bicarbonate and sodium-sulfate genetic water types and meteoric in origin. Hence, it can use the DC-resistivity method in delineating the fault zone and determining the hydro-geophysical characteristics of the fractured aquifer with taking into account the quality of measurements and interpretation.

Stratigraphy, facies architecture, and palaeoenvironment of Neoproterozoic volcanics and volcaniclastic deposits in Fatira area, Central Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

Khalaf, Ezz El Din Abdel Hakim

Fatira area in the Central Eastern Desert, Egypt, is a composite terrane consisting of Neoproterozoic volcanics and sediments laid down in submarine to subaerial environment, intruded by voluminous old to young granitic rocks. The various lithofacies of the study area can be grouped in three distinct lithostratigraphic sequences, which are described here in stratigraphic order, from base to top as the Fatira El Beida, Fatira El Zarqa and Gabal Fatira sequences. Each depositional sequence, is intimately related to volcanic activity separated by time intervals of volcanic inactivity, such as marked hiatuses, reworked volcaniclasts, and or turbidite sedimentation. Four submarine facies groups have been recognized within the oldest, folded eruption sequence of Fatira El Beida. The southern part of the study area is occupied by sheet lava (SL), pillow lavas (PL), pillow breccias (PB), and overlying Bouma turbiditic volcaniclastites (VC). The four facies groups of Fatira El Beida sequence occur in a predictable upward-deepening succession, essentially from base to top, an SL-PL-PB-VC stacking pattern. The coeval tholeiitic mafic and felsic volcaniclastic rocks of this sequence indicate an extensional back-arc tectonic setting. The El Beida depositional sequence appears to fit a submarine-fan and slope-apron environment in an intra-arc site. The Fatira El Zarqa sequence involves a large volume of subaerial calc-alkaline intermediate to felsic volcanics and an unconformably overlying siliciclastic succession comprising clast-supported conglomerates (Gm), massive sandstone sheet floods (Sm) and mudstones (FI), together with a lateritic argillite paleosol (P) top formed in an alluvial-fan system. The youngest rock of Gabal Fatira sequence comprises anorogenic trachydacites and rhyolites with locally emergent domes associated with autobrecciation and sill-dyke rock swarms that could be interpreted as feeders and subvolcanic intrusions. Unconformity and lithofacies assemblages

Clinical characteristics of patients with multiple sclerosis enrolled in a new registry in Egypt.

PubMed

Zakaria, Magd; Zamzam, Dina A; Abdel Hafeez, Mohamed A; Swelam, Mahmoud S; Khater, Shaimaa S; Fahmy, Mai F; Abdel Hady, Ayman; Fouad, Mohamed M; Abdel Nasser, Azza; Aref, Hany; Gadallah, Mohsen

2016-11-01

Epidemiological studies of multiple sclerosis (MS) are lacking in Egypt. To study the characteristics of Egyptian patients with multiple sclerosis in a new registry in a major tertiary referral centre in Cairo, Egypt. Patients were from the project MS database of the Multiple Sclerosis Unit at Ain Shams University Hospitals (N=950). We conducted a detailed medical history and examination including the Expanded Disability Status Scale (EDSS). Females represented 72% of subjects (female: male ratio 2.57:1). The mean age of disease onset was 26.1±7.6 years. Relapsing-remitting MS (RRMS) was the most common presentation (74.6%). Visual or sensory symptoms were the most common at presentation with RRMS, while motor symptoms were the most common presentation in other types of MS. Time to diagnosis was delayed up to 2 years in 27.8% of patients. The mean EDSS score was 3.6±2.1; 55% had EDSS≤3. About half (49%) received a disease-modifying drug. Progressive MS and motor presentation were associated with higher disability. This is the first documented MS registry from Egypt. The clinical characteristics of MS in Egypt was similar to other Arab countries and western countries. MS is more common among females in Egypt, with RRMS being the most common presentation. Visual symptoms and motor symptoms were the most common presentations in RRMS and progressive MS, respectively. Our findings also highlight the value of establishing registries in Egypt in order to be able to study, prospectively, the clinical course of the disease, the response to various DMD's and the epidemiology of MS in Egypt. Copyright © 2016 Elsevier B.V. All rights reserved.

The Nile floodplain, hydroclimatic variability, and its relation with cultural dynamics in ancient Thebes (Luxor, Egypt)

NASA Astrophysics Data System (ADS)

Toonen, Willem H. J.; Graham, Angus; Pennington, Ben; Hunter, Morag; Strutt, Kris; Barker, Dominic; Masson, Aurelia; Emery, Virginia

2016-04-01

The western bank of the river Nile in the Luxor region (Egypt) separates New Kingdom divine temple complexes in the central axis of the river valley from contemporaneous sites on the desert edge and limestone plateau. The intermediate Nile floodplain features relatively few known archaeological sites, but played an important role in the ancient ritual landscape by connecting the focal region of the living (floodplain) with that of the dead (desert). All Royal Funerary Temple Complexes of the New Kingdom period (1539-1077 BCE), which played a central role in the cosmogonical landscape, are positioned within a confined 3.5 km long strip of land on the western edge of the present floodplain. This preferential location, together with contemporary textual sources and tomb scenes suggesting the nearby presence of canals, have led to the hypothesis that natural and human-made waterways may have once connected the main channel of the Nile with the desert edge. Until the present research took place, no detailed study of pre-existing channel networks existed in the region, leaving a gap in current knowledge on the configuration and use of the ancient floodplain. This study presents the results of a multi-disciplinary study aimed at mapping and dating ancient waterways in the Theban region and aims to find evidence for the natural or human origin of such channels. Boreholes and Electric Resistivity Tomography (ERT) were carried out along a transect that connects the edge of the Holocene floodplain with the current position of the river Nile. Satellite imagery and textual sources were also used to augment the fieldwork. The data indicate the presence of an infilled abandoned channel of the Nile in the western distal part of the current floodplain, adjoining the Funerary Temple complexes. Over 2100 ceramic fragments were analysed from the sedimentary infilling of the silted-up river course, dating it to the end of the New Kingdom, and indicating that the channel and temples

Methanogens at the top of the world: occurrence and potential activity of methanogens in newly deglaciated soils in high-altitude cold deserts in the Western Himalayas

PubMed Central

Aschenbach, Katrin; Conrad, Ralf; Řeháková, Klára; Doležal, Jiří; Janatková, Kateřina; Angel, Roey

2013-01-01

Methanogens typically occur in reduced anoxic environments. However, in recent studies it has been shown that many aerated upland soils, including desert soils also host active methanogens. Here we show that soil samples from high-altitude cold deserts in the western Himalayas (Ladakh, India) produce CH4 after incubation as slurry under anoxic conditions at rates comparable to those of hot desert soils. Samples of matured soil from three different vegetation belts (arid, steppe, and subnival) were compared with younger soils originating from frontal and lateral moraines of receding glaciers. While methanogenic rates were higher in the samples from matured soils, CH4 was also produced in the samples from the recently deglaciated moraines. In both young and matured soils, those covered by a biological soil crust (biocrust) were more active than their bare counterparts. Isotopic analysis showed that in both cases CH4 was initially produced from H2/CO2 but later mostly from acetate. Analysis of the archaeal community in the in situ soil samples revealed a clear dominance of sequences related to Thaumarchaeota, while the methanogenic community comprised only a minor fraction of the archaeal community. Similar to other aerated soils, the methanogenic community was comprised almost solely of the genera Methanosarcina and Methanocella, and possibly also Methanobacterium in some cases. Nevertheless, ~103 gdw−1 soil methanogens were already present in the young moraine soil together with cyanobacteria. Our results demonstrate that Methanosarcina and Methanocella not only tolerate atmospheric oxygen but are also able to survive in these harsh cold environments. Their occurrence in newly deglaciated soils shows that they are early colonizers of desert soils, similar to cyanobacteria, and may play a role in the development of desert biocrusts. PMID:24348469

Factors influencing the rates, processes and magnitude of accumulation of carbon in desert soils

NASA Technical Reports Server (NTRS)

Mcfadden, Leslie D.

1994-01-01

This report summarizes research funded through NASA's Soil Landscape Climate Program which includes studies of the systematics of carbon storage and flux in the terrestrial environment, specifically terrestrial soils. Efforts focussed on the nature of carbon behavior in arid environments, where the majority of the carbon is present as inorganic carbon stored as pedogenic carbonate in desert calcic soils. Studies were supported of soils in two areas of western North America's major deserts: the Mojave Desert and the Chihuahuan Desert. Part 1 of this report summarizes the results of research conducted in the area of the Providence Mountains, California in the eastern Mojave Desert. Part 2 of this report summarizes the results of research in the Sevilleta Wildlife Refuge in central New Mexico, one of the sites of the UMN Biology Department's Long Term Ecological Research.

Concentrations of mineral aerosol from desert to plains across the central Rocky Mountains, western United States

USGS Publications Warehouse

Reynolds, Richard L.; Munson, Seth M.; Fernandez, Daniel; Goldstein, Harland L.; Neff, Jason C.

2016-01-01

Mineral dusts can have profound effects on climate, clouds, ecosystem processes, and human health. Because regional dust emission and deposition in western North America are not well understood, measurements of total suspended particulate (TSP) from 2011 to 2013 were made along a 500-km transect of five remote sites in Utah and Colorado, USA. The TSP concentrations in μg m−3 adjusted to a 24-h period were relatively high at the two westernmost, dryland sites at Canyonlands National Park (mean = 135) and at Mesa Verde National Park (mean = 99), as well as at the easternmost site on the Great Plains (mean = 143). The TSP concentrations at the two intervening montane sites were less, with more loading on the western slope of the Rocky Mountains (Telluride, mean = 68) closest to the desert sites compared with the site on the eastern slope (Niwot Ridge, mean = 58). Dust concentrations were commonly highest during late winter-late spring, when Pacific frontal storms are the dominant causes of regional wind. Low concentrations (<7 wt%) of organic matter indicated that rock-derived mineral particles composed most TSP. Most TSP mass was carried by particle sizes larger than 10 μm (PM>10), as revealed by relatively low average daily concentrations of fine (<5 μg m−3; PM2.5) and coarse (<10 μg m−3; PM2.5–10) fractions monitored at or near four sites. Standard air-quality measurements for PM2.5 and PM10 apparently do not capture the large majority of mineral-particulate pollution in the remote western interior U.S.

Napoleon in Egypt.

ERIC Educational Resources Information Center

Fagan, Brian

1989-01-01

Recounts the 1798 Egyptian campaign of Napoleon Bonaparte, whose Scientific and Artistic Commission documented and described the glories of ancient Egypt. The expedition was a disaster by military standards, but the cultural legacies included the Rosetta Stone, and a chronicle entitled "Description de L'Egypte," which did much to…

Stratigraphy, sedimentology and tectonic evolution of the Upper Cretaceous/Paleogene succession in north Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

El Ayyat, Abdalla M.; Obaidalla, Nageh A.

2013-05-01

The stratigraphy, sedimentology and syn-depositional tectonic events (SdTEs) of the Upper Cretaceous/Paleogene (K-P) succession at four localities in north Eastern Desert (NED) of Egypt have been studied. These localities are distributed from south-southwest to north-northeast at Gebel Millaha, at North Wadi Qena, at Wadi El Dakhal, and at Saint Paul Monastery. Lithostratigraphically, four rock units have been recorded: Sudr Formation (Campanian-Maastrichtian); Dakhla Formation (Danian-Selandian); Tarawan Formation (Selandian-Thanetian) and Esna Formation (Thanetian-Ypresian). These rock units are not completely represented all over the study area because some of them are absent at certain sites and others have variable thicknesses. Biostratigrapgically, 18 planktonic foraminiferal zones have been recorded. These are in stratigraphic order: Globotruncana ventricosa Zone (Campanian); Gansserina gansseri, Contusotruncana contusa, Recimguembelina fructicosa, Pseudohastigerina hariaensis, Pseudohastigerina palpebra and Plummerita hantkenenoides zones (Maastrichtian); Praemurica incostans, Praemurica uncinata, Morozovella angulata and Praemurica carinata/Igorina albeari zones (Danian); Igorina albeari, Globanomanlina pseudomenradii/Parasubbotina variospira, Acarinina subsphaerica, Acarinina soldadoensis/Globanomanlina pseudomenardii and Morozovella velascoensis zones (Selandian/Thantian); and Acarinina sibaiyaensis, Pseudohastigerina wilcoxensis/Morozovella velascoensis zones (earliest Ypresian). Sedimentologically, four sedimentary facies belts forming southwest gently-dipping slope to basin transect have been detected. They include tidal flats, outer shelf, slumped continental slope and open marine hemipelagic facies. This transect can be subdivided into a stable basin plain plus outer shelf in the extreme southwestern parts; and an unstable slope shelf platform in the northeastern parts. The unstable slope shelf platform is characterized by open marine hemipelagic

Fugitive dust mitigation for PM{sub 10} attainment in the western Mojave Desert: Recommendations on revegetation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grantz, D.A.; Vaughn, D.L.; Roberts, E.

1997-12-31

Methods to suppress fugitive dust and associated violations of federal PM{sub 10} standards in the western Mojave Desert, following removal of native vegetation by tillage or overgrazing, have been under investigation by a multi-agency task force for several years. Interim recommendations are now possible for this area of high winds, low rainfall, and mostly arable soil with patchy blowing sand. There can be no guarantee of success in any revegetation program in the desert, but the greatest probability of success in this area can be attained by using the native shrub Atriplex canescens, whether direct seeded or transplanted. No additionalmore » nitrogen should be added, and excess nitrogen should be removed if possible, perhaps by a preliminary cropping of barley. This will itself stabilize the soil surface in the short term. Young plants should be protected from herbivory and the harsh elements by using plastic cones. Irrigation is helpful if available. In areas located near native populations of rabbitbrush annual plant cover should be burned but no tillage or other soil disturbance should be imposed, as this facilitates invasion of annual species, including russian thistle, and prevents establishment of rabbitbrush. In sandy areas, seeding with Indian ricegrass may be more effective than with A. canescens. For immediate, short-term, mitigation of blowing dust, furrowing alone and installation of windfences may be effective. Rainfall exhibits high annual variability in arid regions. Absence of fugitive dust emissions in rainy periods, associated with ground cover by annual vegetation, is unlikely to survive several years of low, but normal, rainfall. It is precisely during those periods when rainfall is adequate that long-term revegetation with shrubs has the best chance of success.« less

Environmental Processes and Spectral Reflectance Characteristics Associated with Soil Erosion in Desert Fringe Regions

NASA Technical Reports Server (NTRS)

Jacobberger, P. A.

1987-01-01

Results of analysis of spectral variation of sand dunes in El Ghorabi, Bahariya, Egypt; Tombouctou/Azaouad, Mali; and Tsodilo Hills, western Botswana are presented. Seasonal variations in dune extent and location of dune crests and their relationship to such factors as wind and weather variations are emphasized.

Variations in eruptive style and depositional processes of Neoproterozoic terrestrial volcano-sedimentary successions in the Hamid area, North Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

Khalaf, Ezz El Din Abdel Hakim

2013-07-01

Two contrasting Neoproterozoic volcano-sedimentary successions of ca. 600 m thickness were recognized in the Hamid area, Northeastern Desert, Egypt. A lower Hamid succession consists of alluvial sediments, coherent lava flows, pyroclastic fall and flow deposits. An upper Hamid succession includes deposits from pyroclastic density currents, sills, and dykes. Sedimentological studies at different scales in the Hamid area show a very complex interaction of fluvial, eruptive, and gravitational processes in time and space and thus provided meaningful insights into the evolution of the rift sedimentary environments and the identification of different stages of effusive activity, explosive activity, and relative quiescence, determining syn-eruptive and inter-eruptive rock units. The volcano-sedimentary deposits of the study area can be ascribed to 14 facies and 7 facies associations: (1) basin-border alluvial fan, (2) mixed sandy fluvial braid plain, (3) bed-load-dominated ephemeral lake, (4) lava flows and volcaniclastics, (5) pyroclastic fall deposits, (6) phreatomagmatic volcanic deposits, and (7) pyroclastic density current deposits. These systems are in part coeval and in part succeed each other, forming five phases of basin evolution: (i) an opening phase including alluvial fan and valley flooding together with a lacustrine period, (ii) a phase of effusive and explosive volcanism (pulsatory phase), (iii) a phase of predominant explosive and deposition from base surges (collapsing phase), and (iv) a phase of caldera eruption and ignimbrite-forming processes (climactic phase). The facies architectures record a change in volcanic activity from mainly phreatomagmatic eruptions, producing large volumes of lava flows and pyroclastics (pulsatory and collapsing phase), to highly explosive, pumice-rich plinian-type pyroclastic density current deposits (climactic phase). Hamid area is a small-volume volcano, however, its magma compositions, eruption styles, and inter

DISTRIBUTIONAL CHANGES AND POPULATION STATUS FOR AMPHIBIANS IN THE EASTERN MOJAVE DESERT

EPA Science Inventory

A number of amphibian species historically inhabited sparsely distributed wetlands in the Mojave Desert of western North America, habitats that have been dramatically altered or eliminated as a result of human activities. The population status and distributional changes for amphi...

Geology and geochemistry of the Atacama Desert.

PubMed

Tapia, J; González, R; Townley, B; Oliveros, V; Álvarez, F; Aguilar, G; Menzies, A; Calderón, M

2018-02-14

The Atacama Desert, the driest of its kind on Earth, hosts a number of unique geological and geochemical features that make it unlike any other environment on the planet. Considering its location on the western border of South America, between 17 and 28 °S, its climate has been characterized as arid to hyperarid for at least the past 10 million years. Notably dry climatic conditions of the Atacama Desert have been related to uplift of the Andes and are believed to have played an important role in the development of the most distinctive features of this desert, including: (i) nitrates and iodine deposits in the Central Depression, (ii) secondary enrichment in porphyry copper deposits in the Precordillera, (iii) Li enrichment in salt flats of the Altiplano, and (iv) life in extreme habitats. The geology and physiography of the Atacama Desert have been largely shaped by the convergent margin present since the Mesozoic era. The geochemistry of surface materials is related to rock geochemistry (Co, Cr, Fe, Mn, V, and Zn), salt flats, and evaporite compositions in endorheic basins (As, B, and Li), in addition to anthropogenic activities (Cu, Mo, and Pb). The composition of surface water is highly variable, nonetheless in general it presents a circumneutral pH with higher conductivity and total dissolved solids in brines. Major water constituents, with the exception of HCO 3 - , are generally related to the increase of salinity, and despite the fact that trace elements are not well-documented, surface waters of the Atacama Desert are enriched in As, B, and Li when compared to the average respective concentrations in rivers worldwide.

Enhancing and restoring habitat for the desert tortoise

USGS Publications Warehouse

Abella, Scott R.; Berry, Kristin H.

2016-01-01

Habitat has changed unfavorably during the past 150 y for the desert tortoise Gopherus agassizii, a federally threatened species with declining populations in the Mojave Desert and western Sonoran Desert. To support recovery efforts, we synthesized published information on relationships of desert tortoises with three habitat features (cover sites, forage, and soil) and candidate management practices for improving these features for tortoises. In addition to their role in soil health and facilitating recruitment of annual forage plants, shrubs are used by desert tortoises for cover and as sites for burrows. Outplanting greenhouse-grown seedlings, protected from herbivory, has successfully restored (>50% survival) a variety of shrubs on disturbed desert soils. Additionally, salvaging and reapplying topsoil using effective techniques is among the more ecologically beneficial ways to initiate plant recovery after severe disturbance. Through differences in biochemical composition and digestibility, some plant species provide better-quality forage than others. Desert tortoises selectively forage on particular annual and herbaceous perennial species (e.g., legumes), and forage selection shifts during the year as different plants grow or mature. Nonnative grasses provide low-quality forage and contribute fuel to spreading wildfires, which damage or kill shrubs that tortoises use for cover. Maintaining a diverse “menu” of native annual forbs and decreasing nonnative grasses are priorities for restoring most desert tortoise habitats. Reducing herbivory by nonnative animals, carefully timing herbicide applications, and strategically augmenting annual forage plants via seeding show promise for improving tortoise forage quality. Roads, another disturbance, negatively affect habitat in numerous ways (e.g., compacting soil, altering hydrology). Techniques such as recontouring road berms to reestablish drainage patterns, vertical mulching (“planting” dead plant material

Integration between well logging and seismic reflection techniques for structural a

NASA Astrophysics Data System (ADS)

Mohamed, Adel K.; Ghazala, Hosni H.; Mohamed, Lamees

2016-12-01

Abu El Gharadig basin is located in the northern part of the Western Desert, Egypt. Geophysical investigation in the form of thirty (3D) seismic lines and well logging data of five wells have been analyzed in the oil field BED-1 that is located in the northwestern part of Abu El Gharadig basin in the Western Desert of Egypt. The reflection sections have been used to shed more light on the tectonic setting of Late Jurassic-Early Cretaceous rocks. While the well logging data have been analyzed for delineating the petrophysical characteristics of the two main reservoirs, Bahariya and Kharita Formations. The constructed subsurface geologic cross sections, seismic sections, and the isochronous reflection maps indicate that the area is structurally controlled by tectonic trends affecting the current shape of Abu El Gharadig basin. Different types of faults are well represented in the area, particularly normal one. The analysis of the average and interval velocities versus depth has shown their effect by facies changes and/or fluid content. On the other hand, the derived petrophysical parameters of Bahariya and Kharita Formations vary from well to another and they have been affected by the gas effect and/or the presence of organic matter, complex lithology, clay content of dispersed habitat, and the pore volume.

Analysis of groundwater flow in arid areas with limited hydrogeological data using the Grey Model: a case study of the Nubian Sandstone, Kharga Oasis, Egypt

NASA Astrophysics Data System (ADS)

Mahmod, Wael Elham; Watanabe, Kunio; Zahr-Eldeen, Ashraf A.

2013-08-01

Management of groundwater resources can be enhanced by using numerical models to improve development strategies. However, the lack of basic data often limits the implementation of these models. The Kharga Oasis in the western desert of Egypt is an arid area that mainly depends on groundwater from the Nubian Sandstone Aquifer System (NSAS), for which the hydrogeological data needed for groundwater simulation are lacking, thereby introducing a problem for model calibration and validation. The Grey Model (GM) was adopted to analyze groundwater flow. This model combines a finite element method (FEM) with a linear regression model to try to obtain the best-fit piezometric-level trends compared to observations. The GM simulation results clearly show that the future water table in the northeastern part of the study area will face a severe drawdown compared with that in the southwestern part and that the hydraulic head difference between these parts will reach 140 m by 2060. Given the uncertainty and limitation of available data, the GM produced more realistic results compared with those obtained from a FEM alone. The GM could be applied to other cases with similar data limitations.

Biography of Professor M. El-Bahay Issawi

NASA Astrophysics Data System (ADS)

Abdeen, Mamdouh M.

2017-12-01

Prof. Mohamed El-Bahay Issawi is a remarkable geologist and is without doubt one of the most important Egyptian geologists ever. His work in the Western Desert is extensive and legendary, and it is hard to imagine any single geologist ever again matching the extent of his field work in that remote region. He has had an enormously productive career involving a wide variety of research and applied topics. He discovered the Abu Tartur phosphate deposits, iron ore deposits of the Bahariya Oasis, and the Kalabsha kaolin deposits south of Aswan. He did extensive field work and aerial-photo mapping of the Western Desert over many years and authored many carefully documented papers that are still cited today. He wrote several books about the Phanerozoic geology of Egypt. Prof. Issawi has served his science and his nation over his long and outstanding career.

Ancient Egypt: History 380.

ERIC Educational Resources Information Center

Turk, Laraine D.

"Ancient Egypt," an upper-division, non-required history course covering Egypt from pre-dynastic time through the Roman domination is described. General descriptive information is presented first, including the method of grading, expectation of student success rate, long-range course objectives, procedures for revising the course, major…

A study of Desert Dermatoses in the Thar Desert Region.

PubMed

Chatterjee, Manas; Vasudevan, Biju

2015-01-01

Desert dermatology describes the cutaneous changes and the diseases affecting those living in the desert. Diurnal variation in temperature is high and is characteristic of the deserts. The lack of water affects daily activities and impacts dermatological conditions. Adaptation to the desert is therefore important to survival. This original article focuses on dermatoses occurring in a population in the Thar desert of India, predominantly located in Rajasthan. This is a descriptive study involving various dermatoses seen in patients residing in the Thar desert region over a duration of 3 years. Infections were the most common condition seen among this population and among them fungal infections were the most common. The high incidence of these infections would be accounted for by the poor hygienic conditions due to lack of bathing facilities due to scarcity of water and the consequent sweat retention and overgrowth of cutaneous infective organisms. Pigmentary disorders, photodermatoses, leishmaniasis and skin tumors were found to be more prevalent in this region. Desert sweat dermatitis was another specific condition found to have an increased incidence. The environment of the desert provides for a wide variety of dermatoses that can result in these regions with few of these dermatoses found in much higher incidence than in other regions. The concept of desert dermatology needs to be understood in more details to provide better care to those suffering from desert dermatoses and this article is a step forward in this regard.

Mortality, Recruitment and Change of Desert Tree Populations in a Hyper-Arid Environment

PubMed Central

Andersen, Gidske L.; Krzywinski, Knut

2007-01-01

Background Long-term vegetation changes in hyper-arid areas have long been neglected. Mortality, recruitment and change in populations of the ecologically and culturally important and drought persistent Acacia tortilis and Balanites aegyptiaca are therefore estimated in the Eastern Desert of Egypt, and are related to the primary agents of change, water conditions and human intervention. Methodology A change analysis using high-resolution Corona images (1965) in combination with field data (2003) is the basis for recruitment, mortality and change estimates. For assessing the influence of water conditions on patterns in recruitment and survival, different types of generalized linear models are tested. Conclusions The overall trend in population size in that part of the Eastern Desert studied here is negative. At some sites this negative trend is alarming, because the reduction in mature trees is substantial (>50%) at the same time as recruitment is nearly absent. At a few sites there is a positive trend and better recruitment. Frequent observations of sprouting in saplings indicate that this is an important mechanism to increase their persistence. It is the establishment itself that seems to be the main challenge in the recruitment process. There are indications that hydrological variables and surface water in particular can explain some of the observed pattern in mortality, but our results indicate that direct human intervention, i.e., charcoal production, is the main cause of tree mortality in the Eastern Desert. PMID:17299588

Benthic foraminiferal assemblages as bio-indicators of metals contamination in sediments, Qarun Lake as a case study, Egypt

NASA Astrophysics Data System (ADS)

Abd El Naby, Ahmed; Al Menoufy, Safia; Gad, Ahmed

2018-03-01

Qarun Lake, in the Fayoum Depression of the Western Desert of Egypt, lies within the deepest area in the River Nile flood plain. The drainage water in the Qarun Lake is derived from the discharge of the natural and artificial drainage systems in the Fayoum. Mixed domestic and agricultural pollutants, including heavy metals, nitrates, phosphates, sulfates and pesticides, are discharged into Qarun Lake. Forty-six samples, collected from the undisturbed layer of sediments were used for benthic foraminiferal analysis. Concentrations of some selected trace metal elements (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, V, and Zn) were also determined. Statistical analysis of the abiotic variables (Texture distribution of sediments, Physico-chemical parameters, and metals concentrations) and of the biotic variables (distribution of benthic foraminiferal species) were also performed. The Q-mode cluster analysis of benthic foraminiferal distribution has provided evidence that the Qarun Lake can be subdivided into two cluster groups (A and B), reflecting environmental changes in the lake ecosystem. Cluster B can also be subdivided into two sub-clusters (B1 and B2). The presence of only pollution tolerant taxa with higher faunal density and lower diversity and the absence of the other foraminiferal assemblages in cluster A were attributed to the high concentration of trace metal elements and the strong environmental stress at the eastern and central parts of the Qarun Lake.

Reference intervals and physiologic alterations in hematologic and biochemical values of free-ranging desert tortoises in the Mojave Desert

USGS Publications Warehouse

Christopher, Mary M.; Berry, Kristin H.; Wallis, I.R.; Nagy, K.A.; Henen, B.T.; Peterson, C.C.

1999-01-01

Desert tortoise (Gopherus agassizii) populations have experienced precipitous declines resulting from the cumulative impact of habitat loss, and human and disease-related mortality. Evaluation of hematologic and biochemical responses of desert tortoises to physiologic and environmental factors can facilitate the assessment of stress and disease in tortoises and contribute to management decisions and population recovery. The goal of this study was to obtain and analyze clinical laboratory data from free-ranging desert tortoises at three sites in the Mojave Desert (California, USA) between October 1990 and October 1995, to establish reference intervals, and to develop guidelines for the interpretation of laboratory data under a variety of environmental and physiologic conditions. Body weight, carapace length, and venous blood samples for a complete blood count and clinical chemistry profile were obtained from 98 clinically healthy adult desert tortoises of both sexes at the Desert Tortoise Research Natural area (western Mojave), Goffs (eastern Mojave) and Ivanpah Valley (northeastern Mojave). Samples were obtained four times per year, in winter (February/March), spring (May/June), summer (July/August), and fall (October). Years of near-, above- and below-average rainfall were represented in the 5 yr period. Minimum, maximum and median values, and central 95 percentiles were used as reference intervals and measures of central tendency for tortoises at each site and/or season. Data were analyzed using repeated measures analysis of variance for significant (P < 0.01) variation on the basis of sex, site, season, and interactions between these variables. Significant sex differences were observed for packed cell volume, hemoglobin concentration, aspartate transaminase activity, and cholesterol, triglyceride, calcium, and phosphorus concentrations. Marked seasonal variation was observed in most parameters in conjunction with reproductive cycle, hibernation, or seasonal

Dwarfs in ancient Egypt.

PubMed

Kozma, Chahira

2006-02-15

Ancient Egypt was one of the most advanced and productive civilizations in antiquity, spanning 3000 years before the "Christian" era. Ancient Egyptians built colossal temples and magnificent tombs to honor their gods and religious leaders. Their hieroglyphic language, system of organization, and recording of events give contemporary researchers insights into their daily activities. Based on the record left by their art, the ancient Egyptians documented the presence of dwarfs in almost every facet of life. Due to the hot dry climate and natural and artificial mummification, Egypt is a major source of information on achondroplasia in the old world. The remains of dwarfs are abundant and include complete and partial skeletons. Dwarfs were employed as personal attendants, animal tenders, jewelers, and entertainers. Several high-ranking dwarfs especially from the Old Kingdom (2700-2190 BCE) achieved important status and had lavish burial places close to the pyramids. Their costly tombs in the royal cemeteries and the inscriptions on their statutes indicate their high-ranking position in Egyptian society and their close relation to the king. Some of them were Seneb, Pereniankh, Khnumhotpe, and Djeder. There were at least two dwarf gods, Ptah and Bes. The god Ptah was associated with regeneration and rejuvenation. The god Bes was a protector of sexuality, childbirth, women, and children. He was a favored deity particularly during the Greco-Roman period. His temple was recently excavated in the Baharia oasis in the middle of Egypt. The burial sites and artistic sources provide glimpses of the positions of dwarfs in daily life in ancient Egypt. Dwarfs were accepted in ancient Egypt; their recorded daily activities suggest assimilation into daily life, and their disorder was not shown as a physical handicap. Wisdom writings and moral teachings in ancient Egypt commanded respect for dwarfs and other individuals with disabilities. Copyright (c) 2005 Wiley-Liss, Inc.

Assessing groundwater accessibility in the Kharga Basin, Egypt: A remote sensing approach

NASA Astrophysics Data System (ADS)

Parks, Shawna; Byrnes, Jeffrey; Abdelsalam, Mohamed G.; Laó Dávila, Daniel A.; Atekwana, Estella A.; Atya, Magdy A.

2017-12-01

We used multi-map analysis of remote sensing and ancillary data to identify potentially accessible sites for groundwater resources in the Kharga Basin in the Western Desert of Egypt. This basin is dominated by Cretaceous sandstone formations and extends within the Nubian Sandstone Aquifer. It is dissected by N-S and E-W trending faults, possibly acting as conduits for upward migration of groundwater. Analysis of paleo-drainage using Digital Elevation Model (DEM) generated from the Shuttle Radar Topography Mission (SRTM) data shows that the Kharga was a closed basin that might have been the site of a paleo-lake. Lake water recharged the Nubian Sandstone Aquifer during the wetter Holocene time. We generated the following layers for the multi-map analysis: (1) Fracture density map from the interpretation of Landsat Operational Land Imager (OLI), SRTM DEM, and RADARSAT data. (2) Thermal Inertia (TI) map (for moisture content imaging) from the Moderate Resolution Imaging Spectroradiometer (MODIS) data. (3) Hydraulic conductivity map from mapping lithological units using the Landsat OLI and previously published data. (4) Aquifer thickness map from previously published data. We quantitatively ranked the Kharga Basin by considering that regions of high fracture density, high TI, thicker aquifer, and high hydraulic conductivity have higher potential for groundwater accessibility. Our analysis shows that part of the southern Kharga Basin is suitable for groundwater extraction. This region is where N-S and E-W trending faults intersect, has relatively high TI and it is underlain by thick aquifer. However, the suitability of this region for groundwater use will be reduced significantly when considering the changes in land suitability and economic depth to groundwater extraction in the next 50 years.

Numerical simulation of the effects of urban land-use changes on the local climate of multiple desert cities

NASA Astrophysics Data System (ADS)

Kamal, S. M.; Huang, H. P.; Myint, S. W.

2016-12-01

This study quantifies the effect of urbanization on local climate by numerical simulations for multiple desert cities with a wide range of urban size, baseline climatology, and composition of land cover. The numerical experiments use the Weather Research and Forecasting (WRF) model with multiple layers of nesting centered at a desert city. To extract the influence of land-use changes, twin runs are performed with each pair driven by the same time-varying lateral boundary conditions from reanalysis but different land surface conditions from Landsat observations for 1985 and 2010. The differences in the meteorological fields between the two runs are interpreted as the effects of land-use changes due to urbanization from 1985-2010. Using this strategy, simulations are carried out for five desert cities: (1) Las Vegas, United States, (2) Hotan, China, (3) Kharga, Egypt, (4) Beer Sheva, Israel, and (5) Jodhpur, India. The results of the simulations reveal a common pattern of the climatic effect of desert urbanization with nighttime warming but daytime cooling over areas where urbanization occurred. This effect is mainly confined to the urban area and is not sensitive to the size of the city or the detail of land cover in the surrounding non-urban areas. The pattern is similar in winter and summer. Exceptions to this pattern are found in a few cases in which the noisiness of local circulation, specifically monsoon and land-sea breeze, overwhelms the climatic signal induced by land-use changes. Although the local climatic responses to urbanization are qualitatively similar for the five desert cities, quantitative differences exist in the magnitudes of nighttime warming and daytime cooling. The possible reasons for those secondary differences are discussed.

Thar Desert

NASA Image and Video Library

2001-10-22

This ASTER sub-scene covers an area of 12 x 15 km in NW India in the Thar Desert. The sand dunes of the Thar Desert constantly shift and take on new shapes. Located in northwestern India and eastern Pakistan, the desert is bounded on the south by a salt marsh known as the Rann of Kutch, and on the west by the Indus River plain. About 800 kilometers long and about 490 kilometers wide, the desert's terrain is mainly rolling sandhills with scattered growths of shrub and rock outcroppings. Only about 12 to 25 centimeters of rain fall on the desert each year, and temperatures rise as high as 52 degrees Celsius. Much of the population is pastoral, raising sheep for their wool. The image is located at 24.4 degrees north latitude and 69.3 degrees east longitude. http://photojournal.jpl.nasa.gov/catalog/PIA11094

Analysis of utilization of desert habitats with dynamic simulation

USGS Publications Warehouse

Williams, B.K.

1986-01-01

The effects of climate and herbivores on cool desert shrubs in north-western Utah were investigated with a dynamic simulation model. Cool desert shrublands are extensively managed as grazing lands, and are defoliated annually by domestic livestock. A primary production model was used to simulate harvest yields and shrub responses under a variety of climatic regimes and defoliation patterns. The model consists of six plant components, and it is based on equations of growth analysis. Plant responses were simulated under various combinations of 20 annual weather patterns and 14 defoliation strategies. Results of the simulations exhibit some unexpected linearities in model behavior, and emphasize the importance of both the pattern of climate and the level of plant vigor in determining optimal harvest strategies. Model behaviors are interpreted in terms of shrub morphology, physiology and ecology.

Geological applications of Nimbus radiation data in Middle East

NASA Technical Reports Server (NTRS)

Allison, L. J.

1976-01-01

Plateaus of Eocene limestone and exposed limestone escarpments, in Egypt and Saudi Arabia respectively, were indicated by cool brightness temperatures T sub B (less than 240 to 265 K) by the Nimbus 5 electrically scanning microwave radiometer (ESMR) over a 2-year period. Nubian sandstone, desert eolian sand and igneous metamorphic rocks were differentiated from these limestone areas by warm T sub B values (more than 265 to 300 K). Cool T sub B values in the form of a V were found over broad areas of the Nile Valley and in the western desert of central Egypt. Similar cool T sub B values were shown over limestone-dolomitic hills of the interior Homocline and the Hadramawt plateau of Saudi Arabia. Nimbus 5 and 6 ESMR T sub B values selectively identified intermediate dense rock types (limestone versus sandstone/granite) in the Lake Nasser region whose thermal inertia ranged from 0.035 to 0.06 cal cm to minus 2 C sec 1/2 to minus one half.

Workshop on Extraterrestrial Materials from Cold and Hot Deserts

NASA Technical Reports Server (NTRS)

Schultz, Ludolf (Editor); Franchi, Ian A. (Editor); Reid, Arch M. (Editor); Zolensky, Michael E. (Editor)

1999-01-01

Since 1969 expeditions from Japan, the United States, and European countries have recovered more than 20,000 meteorite specimens from remote ice fields of Antarctica. They represent approximately 4000-6000 distinct falls, more than all non-Antarctic meteorite falls and finds combined. Recently many meteorite specimens of a new "population" have become available: meteorites from hot deserts. It turned out that suitable surfaces in hot deserts, like the Sahara in Africa, the Nullarbor Plain in Western and South Australia, or desert high plains of the U.S. (e.g., Roosevelt County, New Mexico), contain relatively high meteorite concentrations. For example, the 1985 Catalog of Meteorites of the British Museum lists 20 meteorites from Algeria and Libya. Today, 1246 meteorites finds from these two countries have been published in MetBase 4.0. Four workshops in 1982, 1985, 1988, and 1989 have discussed the connections between Antarctic glaciology and Antarctic meteorites, and the differences between Antarctic meteorites and modern falls. In 1995, a workshop addressed differences between meteorites from Antarctica, hot deserts, and modem falls, and the implications of possible different parent populations, infall rates, and weathering processes. Since 1995 many more meteorites have been recovered from new areas of Antarctica and hot deserts around the world. Among these finds are several unusual and interesting specimens like lunar meteorites or SNCs of probable martian origin. The Annual Meeting of the Meteoritical Society took place in 1999 in Johannesburg, South Africa. As most of the recent desert finds originate from the Sahara, a special workshop was planned prior to this meeting in Africa. Topics discussed included micrometeorites, which have been collected in polar regions as well as directly in the upper atmosphere. The title "Workshop on Extraterrestrial Materials from Cold and Hot Deserts" was chosen and the following points were emphasized: (1) weathering

Mesozoic carbonate-siliciclastic platform to basin systems of a South Tethyan margin (Egypt, East Mediterranean)

NASA Astrophysics Data System (ADS)

Tassy, Aurélie; Crouzy, Emmanuel; Gorini, Christian; Rubino, Jean-Loup

2015-04-01

The Mesozoïc Egyptian margin is the south margin of a remnant of the Neo-Tethys Ocean, at the African northern plate boundary. East Mediterranean basin developed during the late Triassic-Early Jurassic rifting with a NW-SE opening direction (Frizon de Lamotte et al., 2011). During Mesozoïc, Egypt margin was a transform margin with a NW-SE orientation of transform faults. In the Eastern Mediterranean basin, Mesozoïc margins are characterized by mixed carbonate-siliciclastics platforms where subsidence and eustacy are the main parameters controlling the facies distribution and geometries of the platform-to-basin transition. Geometries and facies on the platform-slope-basin system, today well constrained on the Levant area, where still poorly known on the Egyptian margin. Geometries and stratigraphic architecture of the Egyptian margin are revealed, thanks to a regional seismic and well data-base provided by an industrial-academic group (GRI, Total). The objective is to understand the sismostratigraphic architecture of the platform-slope-basin system in a key area from Western Desert to Nile delta and Levant margin. Mapping of the top Jurassic and top Cretaceous show seismic geomorphology of the margin, with the cartography of the hinge line from Western Desert to Sinaï. During the Jurassic, carbonate platform show a prograding profile and a distally thickening of the external platform, non-abrupt slope profiles, and palaeovalleys incisions. Since the Cretaceous, the aggrading and retrograding mixed carbonate-siliciclastic platform show an alternation of steep NW-SE oblique segments and distally steepened segments. These structures of the platform edge are strongly controlled by the inherited tethyan transform directions. Along the hinge line, embayments are interpreted as megaslides. The basin infilling is characterised by an alternation of chaotic seismic facies and high amplitude reflectors onlaping the paleoslopes. MTC deposits can mobilize thick sedimentary

Thar Desert

NASA Technical Reports Server (NTRS)

2001-01-01

This ASTER sub-scene covers an area of 12 x 15 km in NW India in the Thar Desert. The sand dunes of the Thar Desert constantly shift and take on new shapes. Located in northwestern India and eastern Pakistan, the desert is bounded on the south by a salt marsh known as the Rann of Kutch, and on the west by the Indus River plain. About 800 kilometers long and about 490 kilometers wide, the desert's terrain is mainly rolling sandhills with scattered growths of shrub and rock outcroppings. Only about 12 to 25 centimeters of rain fall on the desert each year, and temperatures rise as high as 52 degrees Celsius. Much of the population is pastoral, raising sheep for their wool. The image is located at 24.4 degrees north latitude and 69.3 degrees east longitude.

The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

Identification and interpretation of tectonic features from Skylab imagery. [Mojave Desert block of Texas, Arizona, and Chihuahua, Mexico

NASA Technical Reports Server (NTRS)

Abdel-Gawad, M. (Principal Investigator)

1975-01-01

The author has identified the following significant results. Two alternate models for the extension of the Texas zone through the Mojave Desert block have been developed: (1) along the Pisgah Line, and (2) along the eastern Transverse Ranges; this model suggests a counterclockwise rotation of the Mojave block. Analysis of S190B photographs of the western Mojave Desert provides strong evidence for the feasibility of identifying recent fault breaks.

Geological heritage diversity in the Faiyum Oasis (Egypt): A comprehensive assessment

NASA Astrophysics Data System (ADS)

Sallam, Emad S.; Fathy, Esraa E.; Ruban, Dmitry A.; Ponedelnik, Alena A.; Yashalova, Natalia N.

2018-04-01

The Faiyum Oasis in the Western Desert of Egypt is famous for its palaeontological localities (Cenozoic whales, primates, etc.) of global importance, but its geological heritage has been not studied in the modern theoretical frame. The new investigation based on the field studies and the literature review permits comprehensive assessment of the geological heritage diversity in this oasis. For this purposes, unique geological features are inventoried with establishment of their geological essence, rank, relative abundance, and intrinsic diversity. As a result, the existence of ten geological heritage types in the Faiyum Oasis is found. These include palaeontological, palaeogeographical, geomorphological, stratigraphical, sedimentary (merged with mineralogical), hydrological coupled with geochemical, igneous, and economical types. From them, the palaeontological and palaeogeographical types are ranked globally, and the geomorphological and hydrological types are ranked nationally. The other types are either of regional (provincial) or local importance. Some hills and cliffs can serve as viewpoint sites for observation of the local geological landscape. The relative abundance and the intrinsic diversity of the unique geological features vary between low and high. Generally, the concentration of this geological heritage in the Faiyum Oasis permits recognition of the geodiversity hotspot that requires conservation and use for tourism purposes. The protected areas located in the oasis and the existing tourism programs do not offer geoconservation and geotourism activities for the entire hotspot. The possible solution of this problem would be creation of a large geopark similar in its design to the Jeju Island Geopark in South Korea. There are important premises for geotourism development in the Faiyum Oasis and its combination with the archaeological and industrial tourism. Nature conservation failures in this geopark should be avoided; some recommendations are given on

BIOGENIC VOLATILE ORGANIC COMPOUND EMISSIONS FROM DESERT VEGETATION OF THE SOUTHWESTERN U.S.

EPA Science Inventory

Thirteen common plant species in the Mojave and Sonoran Desert regions of the western United States were tested for emissions of biogenic non-methane volatile organic compounds (BVOCs). Only two of the species examined emitted isoprene at rates of 10 µgCg⁻¹ ...

Bistatic GPR Measurements in the Egyptian Western Desert - Measured and Simulated data

NASA Astrophysics Data System (ADS)

Ciarletti, V.; Le Gall, A.; Berthelier, J.; Ney, R.; Corbel, C.; Dolon, F.

2006-12-01

The TAPIR (Terrestrial And Planetary Investigation Radar) instrument has been designed at CETP (Centre d'etude des Environnements Terrestre et Planetaires) to explore the deep Martian subsurface (down to a few kilometers) and to detect liquid water reservoirs. TAPIR is an impulse ground penetrating radar operating at central frequencies ranging from 2 to 4 MHz operating from the surface. In November 2005, an updated version of the instrument working either in monostatic or in bi-static mode was tested in the Egyptian Western Desert. The work presented here focuses on the bi-static measurements performed on the Abou Saied plateau which shows a horizontally layered sub-surface. The electromagnetic signal was transmitted using one of the two orthogonal 70 m loaded electrical dipole antennas of the transmitting GPR. A second GPR, 50 or 100 meters apart, was dedicated to the signal reception. The received waves were characterized by a set of 5 measurements performed on the receiving GPR : the two horizontal components of the electric field and the three composants of the magnetic field. They were used to compute the direction of arrival of the incoming waves and to retrieve more accurately their propagation path and especially to discriminate between waves due to some sub-surface reflecting structure and those due to interaction with the surface clutter. A very efficient synchronization between the two radars enabled us to perform coherent additions up to 2^{31} which improves dramatically the obtained signal to noise ratio. Complementary electromagnetic measurements were conducted on the same site by the LPI (Lunar and Planetary Institute) and the SwRI (Southwest Research Institute). They provided independent information which helped the interpretation of the TAPIR data. Accurate simulations obtained by FDTD taking into account the information available are presented and used for both the interpretation of the measured data and the validation of the instrument.

The use of multifrequency and polarimetric SIR-C/X-SAR data in geologic studies of Bir Safsaf, Egypt

USGS Publications Warehouse

Schaber, G.G.; McCauley, J.F.; Breed, C.S.

1997-01-01

Bir Safsaf, within the hyperarid 'core' of the Sahara in the Western Desert of Egypt, was recognized following the SIR-A and SIR-B missions in the 1980s as one of the key localities in northeast Africa, where penetration of dry sand by radar signals delineates previously unknown, sand-buried paleodrainage valleys ('radar-rivers') of middle Tertiary to Quaternary age. The Bir Safsaf area was targeted as a focal point for further research in sand penetration and geologic mapping using the multifrequency and polarimetric SIR-C/X-SAR sensors. Analysis of the SIR-C/X-SAR data from Bir Safsaf provides important new information on the roles of multiple SAR frequency and polarimetry in portraying specific types of geologic units, materials, and structures mostly hidden from view on the ground and on Landsat TM images by a relatively thin, but extensive blanket of blow sand. Basement rock units (granitoids and gneisses) and the fractures associated with them at Bir Safsaf are shown here for the first time to be clearly delineated using C- and L-band SAR images. The detectability of most geologic features is dependent primarily on radar frequency, as shown for wind erosion patterns in bedrock at X-band (3 cm wavelength), and for geologic units and sand and clay-filled fractures in weathered crystal-line basement rocks at C-band (6 cm) and L-band (24 cm). By contrast, Quaternary paleodrainage channels are detectable at all three radar frequencies owing, among other things, to an usually thin cover of blow sand. The SIR-C/X-SAR data investigated to date enable us to make specific recommendations about the utility of certain radar sensor configurations for geologic and paleoenvironmental reconnaissance in desert regions.Analysis of the shuttle imaging radar-C/X-synthetic aperture radar (SIR-C/X-SAR) data from Bir Safsaf provides important new information on the roles of multiple SAR frequency and polarimetry in portraying specific types of geologic units, materials, and

Morphologic-anthropological investigations in tomb K93.12 at Dra' Abu el-Naga (Western Thebes, Egypt).

PubMed

Lösch, Sandra; Moghaddam, Negahnaz; Paladin, Alice; Rummel, Ute; Hower-Tilmann, Estelle; Zink, Albert

2014-01-01

In this study we present the analysis of the human remains from tomb K93.12 in the Ancient Egyptian necropolis of Dra' Abu el-Naga, located opposite the modern city of Luxor in Upper Egypt on the western bank of the Nile. Archaeological findings indicate that the rock tomb was originally built in the early 18th dynasty. Remains of two tomb-temples of the 20th dynasty and the looted burial of the High Priest of Amun Amenhotep have been identified. After the New Kingdom the tomb was reused as a burial place until the 26th dynasty. The skeletal and mummified material of the different tomb areas underwent a detailed anthropological and paleopathological analysis. The human remains were mostly damaged and scattered due to extensive grave robberies. In total, 79 individuals could be partly reconstructed and investigated. The age and sex distribution revealed a male predominance and a high percentage of young children (< 6 years) and adults in the range of 20 to 40 years. The paleopathological analysis showed a high prevalence of stress markers such as cribra orbitalia in the younger individuals, and other pathological conditions such as dental diseases, degenerative diseases and a possible case of ankylosing spondylitis. Additionally, 13 mummies of an intrusive waste pit could be attributed to three different groups belonging to earlier time periods based on their style of mummification and materials used. The study revealed important information on the age and sex distribution and diseases of the individuals buried in tomb K93.12.

Nile Delta, Egypt

NASA Technical Reports Server (NTRS)

1982-01-01

The Nile Delta of Egypt (30.0N, 31.0E) irrigated by the Nile River and its many distributaries, is some of the richest farm land in the world and home to some 45 million people, over half of Egypt's population of 57 million. The capital city of Cairo is at the apex of the delta in the middle of the scene. Across the river from Cairo can be seen the three big pyramids and sphinx at Giza and the Suez Canal is just to the right of the delta.

Comparisons of diazotrophic communities in native and agricultural desert ecosystems reveal plants as important drivers in diversity

PubMed Central

Köberl, Martina; Erlacher, Armin; Ramadan, Elshahat M.; El-Arabi, Tarek F.; Müller, Henry; Bragina, Anastasia; Berg, Gabriele

2015-01-01

Diazotrophs provide the only biological source of fixed atmospheric nitrogen in the biosphere. Although they are the key player for plant-available nitrogen, less is known about their diversity and potential importance in arid ecosystems. We investigated the nitrogenase gene diversity in native and agricultural desert soil as well as within root-associated microbiota of medicinal plants grown in Egypt through the combination of nifH-specific qPCR, fingerprints, amplicon pyrosequencing and fluorescence in situ hybridization–confocal laser scanning microscopy. Although the diazotrophic microbiota were characterized by generally high abundances and diversity, statistically significant differences were found between both soils, the different microhabitats, and between the investigated plants (Matricaria chamomilla L., Calendula officinalis L. and Solanum distichum Schumach. and Thonn.). We observed a considerable community shift from desert to agriculturally used soil that demonstrated a higher abundance and diversity in the agro-ecosystem. The endorhiza was characterized by lower abundances and only a subset of species when compared to the rhizosphere. While the microbiomes of the Asteraceae were similar and dominated by potential root-nodulating rhizobia acquired primarily from soil, the perennial S. distichum generally formed associations with free-living nitrogen fixers. These results underline the importance of diazotrophs in desert ecosystems and additionally identify plants as important drivers in functional gene pool diversity. PMID:26705571

Comparisons of diazotrophic communities in native and agricultural desert ecosystems reveal plants as important drivers in diversity.

PubMed

Köberl, Martina; Erlacher, Armin; Ramadan, Elshahat M; El-Arabi, Tarek F; Müller, Henry; Bragina, Anastasia; Berg, Gabriele

2016-02-01

Diazotrophs provide the only biological source of fixed atmospheric nitrogen in the biosphere. Although they are the key player for plant-available nitrogen, less is known about their diversity and potential importance in arid ecosystems. We investigated the nitrogenase gene diversity in native and agricultural desert soil as well as within root-associated microbiota of medicinal plants grown in Egypt through the combination of nifH-specific qPCR, fingerprints, amplicon pyrosequencing and fluorescence in situ hybridization-confocal laser scanning microscopy. Although the diazotrophic microbiota were characterized by generally high abundances and diversity, statistically significant differences were found between both soils, the different microhabitats, and between the investigated plants (Matricaria chamomilla L., Calendula officinalis L. and Solanum distichum Schumach. and Thonn.). We observed a considerable community shift from desert to agriculturally used soil that demonstrated a higher abundance and diversity in the agro-ecosystem. The endorhiza was characterized by lower abundances and only a subset of species when compared to the rhizosphere. While the microbiomes of the Asteraceae were similar and dominated by potential root-nodulating rhizobia acquired primarily from soil, the perennial S. distichum generally formed associations with free-living nitrogen fixers. These results underline the importance of diazotrophs in desert ecosystems and additionally identify plants as important drivers in functional gene pool diversity. © FEMS 2015.

Geographic overview: Climate, phenology, and disturbance regimes in steppe and desert communities

Treesearch

B. J. Weddell

1996-01-01

In midwestern steppes, precipitation peaks in summer, whereas west of the Rocky Mountains, steppes are characterized by summer drought. In western deserts, the amount of precipitation is highly variable. These different climatic regimes result in differences in prevalence of and resilience to disturbances such as herbivory, and differences in susceptibility to invasion...

Childbirth in ancient Egypt.

PubMed

Chamberlain, Geoffrey

2004-11-01

Medicine in ancient Egypt was much more advanced than the rest of the Biblical world, especially in trauma surgery. Care at the time of childbirth was however virtually non-existent. There were no trained obstetricians or midwives but a galaxy of gods were at hand. This article traces what we can piece together about pregnancy of childbirth from the evidence we have in tombs and papyri of Egypt.

Depositional environments and sequence architecture of the Raha and Abu Qada formations (Cenomanian-Turonian), west central Sinai, Egypt

NASA Astrophysics Data System (ADS)

Anan, Tarek I.; El-Shahat, Adam; Genedi, Adel; Grammer, Michael

2013-06-01

Cenomanian-Turonian deposits are important reservoirs for many oil fields in the Western Desert and the Gulf of Suez region of Egypt. Study of the Raha and Abu Qada formations (Cenomanian-Turonian), from five dip-oriented outcrop locations in west central Sinai; indicates deposition of a mixed siliciclastic-carbonate system on a ramp setting. The inner ramp facies (bivalve and benthonic foraminiferal wackestone) grades northward to the mid ramp facies (echinoderm calcisphere packstone, and oyster floatstone), and outer ramp facies (planktonic foraminiferal wackestone and calcisphere wackestone). The two studied formations comprise one second-order depositional sequence (duration of approximately 10 Million years). This large scale sequence includes four third-order depositional sequences, three of which are observed in the Raha Formation, with the other one recorded in the Abu Qada Formation. Because west central Sinai was tectonically stable during the Cenomanian and Turonian, the main factor controlling the lateral and vertical distribution of facies tracts is likely due to changes in the relative sea level. The Cenomanian-Turonian boundary event is known as the largest oceanic anoxic event during the Cretaceous. This global event has been documented in three of the studied sections. The recorded δ13C excursions range from +3.04‰ to +5.24‰. These high positive excursions in δ13C are associated with highly negative values of δ18O (values range from -6.01‰ to -1.38‰).

[Tuberculosis in ancient Egypt].

PubMed

Ziskind, B; Halioua, B

2007-12-01

Did Tuberculosis plague Ancient Egypt five millennia ago? Some medical papyri appear to evoke tuberculosis. Egyptian physicians did not individualize it, but they seem to have noticed some of its clinical expressions, such as cough, cervical adenitis, and cold abscesses. In Egyptian iconography, some cases of hump-backs were probably due to Pott's disease of the spine Descriptive paleopathology, born with the 20th century, has identified pulmonary and especially spinal lesions compatible with tuberculosis. Progress of molecular biology has made a decisive contribution with the diagnosis of tuberculosis on ancient samples. Tuberculosis has been identified using PCR in nearly a third of the Egyptian mummies recently examined. Spoligotyping has made it possible to re-evaluate the phylogenic tree of the Mycobacterium tuberculosis complex in Ancient Egypt. Tuberculosis certainly plagued the Nile Valley and appears to have been an important cause of mortality in Ancient Egypt.

Geomorphologic and geologic overview for water resources development: Kharit basin, Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

Mosaad, Sayed

2017-10-01

This study demonstrates the importance of geomorphologic, geologic and hydrogeologic assessment as an efficient approach for water resources development in the Kharit watershed. Kharit is one of largest watersheds in the Eastern Desert that lacks water for agricultural and drinking purposes, for the nomadic communities. This study aims to identify and evaluate the geomorphologic, geologic and hydrogeologic conditions in the Kharit watershed relative to water resource development using remote sensing and GIS techniques. The results reveal that the watershed contains 15 sub-basins and morphometric analyses show high probability for flash floods. These hazards can be managed by constructing earth dikes and masonry dams to minimize damage from flash floods and allow recharge of water to shallow groundwater aquifers. The Quaternary deposits and the Nubian sandstone have moderate to high infiltration rates and are relatively well drained, facilitating surface runoff and deep percolation into the underlying units. The sediments cover 54% of the watershed area and have high potential for groundwater extraction.

Operation Desert Shield

Science.gov Websites

Bureau Iraq invades Kuwait, Aug. 2, 1990. Operation Desert Shield begins, Aug. 7, 1990. First U.S. forces Operation Desert Shield-related U.S. death, Aug. 12, 1990. President George Bush authorizes first call-up of Bureau Operation Desert Storm and air war phase begins, 3 a.m., Jan. 17, 1991 (Jan. 16, 7 p.m. Eastern

Mate desertion in the snail kite

USGS Publications Warehouse

Beissinger, S.R.; Snyder, N.F.R.

1988-01-01

Mate desertion during the breeding cycle was documented at 28 of 36 (78%) snail kite, Rostrhamus sociabilis nests in Florida between 1979 and 1983. Offspring mortality occurred at only one deserted nest, however. Parents that were deserted by their mates continued to care for their young until independence (3?5 additional weeks) and provided snails at a rate similar to that of both parents combined before desertion. Males and females deserted with nearly equal frequency, except in 1982 when more females deserted. No desertion occurred during drought years, whereas desertion occurred at nearly every nest during favourable conditions. The occurrence of mate desertion was generally related to indirect measures of snail abundance: foraging range, snail delivery rates to the young and growth rates. Small broods were deserted more frequently by females than by males and tended to be deserted earlier than large ones. After desertion, deserters had the opportunity to re-mate and nest again since breeding seasons were commonly lengthy, but whether they did so was impossible to determine conclusively in most cases. The deserted bird sometimes incurred increased energetic costs and lost breeding opportunities during periods of monoparental care.

Mesozoic evolution of the northeast African shelf margin, Libya and Egypt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Aadland, R.K.; Schamel, S.

1988-08-01

The present tectonic features of the northeast African shelf margin between the Nile delta and the Gulf of Sirte are products of (1) precursory late Paleozoic basement arches, (2) early Mesozoic rifting and plate separation, and (3) Late Cretaceous structural inversion. Isopach and structural maps, cross sections, and sediment accumulation (geohistory) curves constructed from 89 wells in the Western Desert and 27 wells in northeastern Libya depict the structural and stratigraphic development of the northeast African shelf margin.

Deserts : geology and resources

USGS Publications Warehouse

Walker, Alta S.

1996-01-01

Approximately one-third of the Earth's land surface is desert, arid land with meager rainfall that supports only sparse vegetation and a limited population of people and animals. Deserts stark, sometimes mysterious worlds have been portrayed as fascinating environments of adventure and exploration from narratives such as that of Lawrence of Arabia to movies such as "Dune." These arid regions are called deserts because they are dry. They may be hot, they may be cold. They may be regions of sand or vast areas of rocks and gravel peppered with occasional plants. But deserts are always dry. Deserts are natural laboratories in which to study the interactions of wind and sometimes water on the arid surfaces of planets. They contain valuable mineral deposits that were formed in the arid environment or that were exposed by erosion. Because deserts are dry, they are ideal places for human artifacts and fossils to be preserved. Deserts are also fragile environments. The misuse of these lands is a serious and growing problem in parts of our world.

Exercise Desert Rock, Staff Memorandums. Army, Camp Desert Rock, Nevada.

DTIC Science & Technology

1957-01-01

I AD-AGAG 257 EXERCISE DESERT ROCK LAS VEGAS NV F/6 IS/ 3 EXERCISE DESERT ROCK, STAFF MEMORANDUMS. ARMY. CAMP DESERT ROCK-ETClUlCASIFE mm95i mm... Exercise Safety Progra - . 1. PUrose: To establish ane’ffective safety progr.Rm toreduce, and keep to a minimum, accident,1 manpower and monetary losses. at...agencies will be- followed. Supervispry personnel will: become familiar with those that Pre applicable to thei£r... operations. The Exercise Safety

Assessment of chemical and genetic variability in Tanacetum gracile accessions collected from cold desert of Western Himalaya.

PubMed

Mahajan, Vidushi; Chouhan, Rekha; Kitchlu, Surinder; Bindu, Kushal; Koul, Sushma; Singh, Bikarma; Bedi, Yashbir S; Gandhi, Sumit G

2018-06-01

Genetic diversity is essential for survival and adaptation of high altitude plants such as those of Tanacetum genus, which are constantly exposed to environmental stress. We collected flowering shoots of ten accessions of Tanacetum gracile Hook.f. & Thomson (Asteraceae) (Tg 1-Tg 10), from different regions of cold desert of Western Himalaya. Chemical profile of the constituents, as inferred from GC-MS, exhibited considerable variability. Percentage yield of essential oil ranged from 0.2 to 0.75% (dry-weight basis) amongst different accessions. Tg 1 and Tg 6 were found to produce high yields of camphor (46%) and lavandulol (41%), respectively. Alpha -phellendrene, alpha -bisabool, p -cymene and chamazulene were the main oil components in other accessions. Genetic variability among the accessions was studied using RAPD markers as well as by sequencing and analyzing nuclear 18S rDNA, and plastid rbcL and matK loci. The polymorphic information content (PIC) of RAPD markers ranged from 0.18 to 0.5 and the analysis clustered the accessions into two major clades. The present study emphasized the importance of survey, collection, and conservation of naturally existing chemotypes of medicinal and aromatic plants, considering their potential use in aroma and pharmaceutical industry.

Nile River Delta, Egypt

NASA Technical Reports Server (NTRS)

1984-01-01

The Nile River Delta of Egypt (30.0N, 31.0E) irrigated by the Nile River and its many distributaries, is some of the richest farm land in the world and home to some 45 million people, over half of Egypt's population. The capital city of Cairo is at the apex of the delta. Just across the river from Cairo can be seen the ancient three big pyramids and sphinx at Giza and the Suez Canal is just to the right of the delta.

Nile River Delta, Egypt

NASA Image and Video Library

1984-10-13

The Nile River Delta of Egypt (30.0N, 31.0E) irrigated by the Nile River and its many distributaries, is some of the richest farm land in the world and home to some 45 million people, over half of Egypt's population. The capital city of Cairo is at the apex of the delta. Just across the river from Cairo can be seen the ancient three big pyramids and sphinx at Giza and the Suez Canal is just to the right of the delta.

Microearthquake studies in Egypt carried out by the geological survey of Egypt

NASA Astrophysics Data System (ADS)

Boulos, Fouad K.; Morgan, Paul; Toppozada, Tousson R.

1987-07-01

Extensive microearthquake studies have been conducted in Egypt as a joint project between scientists from the Egyptian Geological Survey and Mining Authority (EGSMA) and U.S. scientists. At this stage, a great part of the data has been analyzed and two intensively active areas have been located: one in the Abu Dabbab area of the Eastern Desert, the second at the mouth of the Gulf of Suez near Gubal Island (Daggett et al., 1980). Both sites have been reported to be the epicenters of large earthquakes in 1955 and 1969, respectively. A few scattered earthquakes have also been located in the northern part of the Red Sea, some of which lie along its median axis (Daggett et al., 1986) adding to evidence for the medial opening of the northern Red Sea. After the occurrence of an earthquake (M = 5.5) in the Aswan region on 14 November 1981, continuous recording of the many aftershocks was carried out by EGSMA for about seven months from December 1981 to July 1982, when the temporary network was replaced by a network of telemetered seismographs installed and operated by Helwan Institute of Astronomy and Geophysics in cooperation with scientists from Lamont and Doherty Geological Observatory (LDGO). The majority of epicenters are concentrated in the vicinity of G. Marawa about 65 km upstream of Aswan Dam, along the E-W Kalabsha fault. The observed focal mechanism is consistent with a right-lateral strike-slip motion on the Kalabsha fault. Analysis of Aswan microearthquakes has been done by EGSMA in cooperation with scientists from California Division of Mines and Geology (CDMG).

Inclusiveness in Higher Education in Egypt

ERIC Educational Resources Information Center

Cupito, Emily; Langsten, Ray

2011-01-01

In Egypt, before 1952, education, especially higher education, was the province of a privileged few. After the 1952 Revolution, in pursuit of social justice and economic development, Egypt's leaders eliminated fees, instituted a universal admission examination, promised government employment to all graduates of higher education, and expanded the…

Integration of remote sensing, geochemical and field data in the Qena-Safaga shear zone: Implications for structural evolution of the Eastern Desert, Egypt

NASA Astrophysics Data System (ADS)

El-Din, Gamal Kamal; Abdelkareem, Mohamed

2018-05-01

The Qena-Safaga shear zone (QSSZ) represents a significant structural characteristic in the Eastern Desert of Egypt. Remote Sensing, field and geochemical data were utilized in the present study. The results revealed that the QSSZ dominated by metamorphic complex (MC) that intruded by syn-tectonic granitoids. The low angle thrust fault brings calc-alkaline metavolcanics to overlie MC and its association. Subsequently, the area is dissected by strike-slip faults and the small elongated basins of Hammamat sediments of Precambrian were accumulated. The MC intruded by late-to post-tectonic granites (LPG) and Dokhan Volcanics which comprise felsic varieties forming distinctive columnar joints. Remote sensing analysis and field data revealed that major sub-vertical conspicuous strike-slip faults (SSF) including sinistral NW-SE and dextral ca. E-W shaped the study area. Various shear zones that accompanying the SSF are running NW-SE, NE-SW, E-W, N-S and ENE-WSW. The obtained shear sense presented a multiphase of deformation on each trend. i.e., the predominant NW-SE strike-slip fault trend started with sinistral displacement and is reactivated during later events to be right (dextral) strike slip cutting with dextral displacement the E-W trending faults; while NE-SW movements are cut by both the N-S and NNW - SSE trends. Remote sensing data revealed that the NW-SE direction that dominated the area is associated with hydrothermal alteration processes. This allowed modifying the major and trace elements of the highly deformed rocks that showed depletion in SiO2 and enrichments in Fe2O3, MnO, Al2O3, TiO2, Na2O, K2O, Cu, Zn and Pb contents. The geochemical signatures of major and trace elements revealed two types of granites including I-type calc-alkaline granites (late-to post-tectonic) that formed during an extensional regime. However, syn-tectonic granitoids are related to subduction-related environment.

Shelf architectures of an isolated Late Cretaceous carbonate platform margin, Galala Mountains (Eastern Desert, Egypt)

NASA Astrophysics Data System (ADS)

Scheibner, C.; Marzouk, A. M.; Kuss, J.

2001-12-01

An asymmetrical carbonate platform margin to basin transect has been investigated in the Upper Campanian-Maastrichtian succession of the Galala Mountains, northern Egypt. Identification of systems tracts and their lateral correlation was possible in slope sections only, whereas the monotonous chalk-marl alternations of the basinal sections could not be subdivided with respect to sequence stratigraphic terminology. The platform asymmetry is expressed by varying large-scale depositional architectures exhibiting a rimmed platform with a sigmoidal slope curvature in south-easterly dip-sections and a ramp with a linear slope curvature in south-westerly dip-sections. The rimmed platform is subdivided into a gentle upper slope and a steep lower slope. The platform formed as a result of the initial topography that was controlled by the tectonic uplift of the Northern Galala/Wadi Araba Syrian Arc structure. The calculated angles of the steep lower slope of the rimmed part range from 5 to 8°, whereas the ramp part has an angle of less than 0.1°.

Integrated Human Futures Modeling in Egypt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Passell, Howard D.; Aamir, Munaf Syed; Bernard, Michael Lewis

The Integrated Human Futures Project provides a set of analytical and quantitative modeling and simulation tools that help explore the links among human social, economic, and ecological conditions, human resilience, conflict, and peace, and allows users to simulate tradeoffs and consequences associated with different future development and mitigation scenarios. In the current study, we integrate five distinct modeling platforms to simulate the potential risk of social unrest in Egypt resulting from the Grand Ethiopian Renaissance Dam (GERD) on the Blue Nile in Ethiopia. The five platforms simulate hydrology, agriculture, economy, human ecology, and human psychology/behavior, and show how impacts derivedmore » from development initiatives in one sector (e.g., hydrology) might ripple through to affect other sectors and how development and security concerns may be triggered across the region. This approach evaluates potential consequences, intended and unintended, associated with strategic policy actions that span the development-security nexus at the national, regional, and international levels. Model results are not intended to provide explicit predictions, but rather to provide system-level insight for policy makers into the dynamics among these interacting sectors, and to demonstrate an approach to evaluating short- and long-term policy trade-offs across different policy domains and stakeholders. The GERD project is critical to government-planned development efforts in Ethiopia but is expected to reduce downstream freshwater availability in the Nile Basin, fueling fears of negative social and economic impacts that could threaten stability and security in Egypt. We tested these hypotheses and came to the following preliminary conclusions. First, the GERD will have an important short-term impact on water availability, food production, and hydropower production in Egypt, depending on the short- term reservoir fill rate. Second, the GERD will have a very small

Combating desertification: building on traditional knowledge systems of the Thar Desert communities.

PubMed

Gaur, Mahesh K; Gaur, Hemlata

2004-12-01

The Thar Desert of western India is known for its rich and ancient culture system and traditions. The communities have long been part of the Thar Desert ecosystem and have evolved specific strategies to live in harmony with its hostile environment. This culture has provided several miracle plants of immense food and medicinal value to modern civilisation. The ancient rural livelihood knowledge system reflects time-tested techno-scientific knowledge with a proven track record of sustainability, especially during natural hazards like drought and famines. In addition, several of the traditional skills of local communities in arts and crafts, music and instruments have made modern man aware of the art and techniques of sustainably utilising local biological resources and preserving their biodiversity along with using waste products of the forests, without harming the desert ecosystem. Traditional cultural and socio-religious values are fast dwindling under the impact of materialistic approach, industrialisation and development. This paper endeavours to illustrate the need to assist and propagate indigenous rural livelihood systems rather than mindlessly replace or abandon them as a result of state bureaucracies.

Skeletal dysplasia in ancient Egypt.

PubMed

Kozma, Chahira

2008-12-01

The ancient Egyptian civilization lasted for over 3000 years and ended in 30 BCE. Many aspects of ancient Egyptian culture, including the existence of skeletal dysplasias, and in particular achondroplasia, are well known through the monuments and records that survived until modern times. The hot and dry climate in Egypt allowed for the preservation of bodies and skeletal anomalies. The oldest dwarf skeleton, the Badarian skeleton (4500 BCE), possibly represents an epiphyseal disorder. Among the remains of dwarfs with achondroplasia from ancient Egypt (2686-2190 BCE), exists a skeleton of a pregnant female, believed to have died during delivery with a baby's remains in situ. British museums have partial skeletons of dwarfs with achondroplasia, humeri probably affected with mucopolysaccharidoses, and a skeleton of a child with osteogenesis imperfecta. Skeletal dysplasia is also found among royal remains. The mummy of the pharaoh Siptah (1342-1197 BCE) shows a deformity of the left leg and foot. A mummified fetus, believed to be the daughter of king Tutankhamun, has scoliosis, spina bifida, and Sprengel deformity. In 2006 I reviewed the previously existing knowledge of dwarfism in ancient Egypt. The purpose of this second historical review is to add to that knowledge with an expanded contribution. The artistic documentation of people with skeletal dysplasia from ancient Egypt is plentiful including hundreds of amulets, statues, and drawing on tomb and temple walls. Examination of artistic reliefs provides a glance of the role of people with skeletal dysplasia and the societal attitudes toward them. Both artistic evidence and moral teachings in ancient Egypt reveal wide integration of individuals with disabilities into the society. Copyright (c) 2008 Wiley-Liss, Inc.

Effects of desert wildfires on desert tortoise (Gopherus agassizii) and other small vertebrates

USGS Publications Warehouse

Esque, T.C.; Schwalbe, C.R.; DeFalco, L.A.; Duncan, R.B.; Hughes, T.J.

2003-01-01

We report the results of standardized surveys to determine the effects of wildfires on desert tortoises (Gopherus agassizii) and their habitats in the northeastern Mojave Desert and northeastern Sonoran Desert. Portions of 6 burned areas (118 to 1,750 ha) were examined for signs of mortality of vertebrates. Direct effects of fire in desert habitats included animal mortality and loss of vegetation cover. A range of 0 to 7 tortoises was encountered during surveys, and live tortoises were found on all transects. In addition to desert tortoises, only small (<1 kg) mammals and reptiles (11 taxa) were found dead on the study areas. We hypothesize that indirect effects of fire on desert habitats might result in changes in the composition of diets and loss of vegetation cover, resulting in an increase in predation and loss of protection from temperature extremes. These changes in habitat also might cause changes in vertebrate communities in burned areas.

Atmospheric aerosols size distribution properties in winter and pre-monsoon over western Indian Thar Desert location

DOE Office of Scientific and Technical Information (OSTI.GOV)

Panwar, Chhagan, E-mail: chhaganpanwar@gmail.com; Vyas, B. M.

The first ever experimental results over Indian Thar Desert region concerning to height integrated aerosols size distribution function in particles size ranging between 0.09 to 2 µm such as, aerosols columnar size distribution (CSD), effective radius (R{sub eff}), integrated content of total aerosols (N{sub t}), columnar content of accumulation and coarse size aerosols particles concentration (N{sub a}) (size < 0.5 µm) and (N{sub c}) (size between 0.5 to 2 µm) have been described specifically during winter (a stable weather condition and intense anthropogenic pollution activity period) and pre-monsoon (intense dust storms of natural mineral aerosols as well as unstable atmospheric weather condition period)more » at Jaisalmer (26.90°N, 69.90°E, 220 m above surface level (asl)) located in central Thar desert vicinity of western Indian site. The CSD and various derived other aerosols size parameters are retrieved from their average spectral characteristics of Aerosol Optical Thickness (AOT) from UV to Infrared wavelength spectrum measured from Multi-Wavelength solar Radiometer (MWR). The natures of CSD are, in general, bio-modal character, instead of uniformly distributed character and power law distributions. The observed primary peaks in CSD plots are seen around about 10{sup 13} m{sup 2} μm{sup −1} at radius range 0.09-0.20 µm during both the seasons. But, in winter months, secondary peaks of relatively lower CSD values of 10{sup 10} to 10{sup 11} m{sup 2}/μm{sup −1} occur within a lower radius size range 0.4 to 0.6 µm. In contrast to this, while in dust dominated and hot season, the dominated secondary maxima of the higher CSD of about 10{sup 12} m{sup 2}μm{sup −3} is found of bigger aerosols size particles in a rage of 0.6 to 1.0 µm which is clearly demonstrating the characteristics of higher aerosols laden of bigger size aerosols in summer months relative to their prevailed lower aerosols loading of smaller size aerosols

Characterization of the Sonoran desert as a radiometric calibration target for Earth observing sensors

USGS Publications Warehouse

Angal, Amit; Chander, Gyanesh; Xiong, Xiaoxiong; Choi, Tae-young; Wu, Aisheng

2011-01-01

To provide highly accurate quantitative measurements of the Earth's surface, a comprehensive calibration and validation of the satellite sensors is required. The NASA Moderate Resolution Imaging Spectroradiometer (MODIS) Characterization Support Team, in collaboration with United States Geological Survey, Earth Resources Observation and Science Center, has previously demonstrated the use of African desert sites to monitor the long-term calibration stability of Terra MODIS and Landsat 7 (L7) Enhanced Thematic Mapper plus (ETM+). The current study focuses on evaluating the suitability of the Sonoran Desert test site for post-launch long-term radiometric calibration as well as cross-calibration purposes. Due to the lack of historical and on-going in situ ground measurements, the Sonoran Desert is not usually used for absolute calibration. An in-depth evaluation (spatial, temporal, and spectral stability) of this site using well calibrated L7 ETM+ measurements and local climatology data has been performed. The Sonoran Desert site produced spatial variability of about 3 to 5% in the reflective solar regions, and the temporal variations of the site after correction for view-geometry impacts were generally around 3%. The results demonstrate that, barring the impacts due to occasional precipitation, the Sonoran Desert site can be effectively used for cross-calibration and long-term stability monitoring of satellite sensors, thus, providing a good test site in the western hemisphere.

Namib Desert Soil Microbial Community Diversity, Assembly, and Function Along a Natural Xeric Gradient.

PubMed

Scola, Vincent; Ramond, Jean-Baptiste; Frossard, Aline; Zablocki, Olivier; Adriaenssens, Evelien M; Johnson, Riegardt M; Seely, Mary; Cowan, Don A

2018-01-01

The hyperarid Namib desert is a coastal desert in southwestern Africa and one of the oldest and driest deserts on the planet. It is characterized by a west/east increasing precipitation gradient and by regular coastal fog events (extending up to 75 km inland) that can also provide soil moisture. In this study, we evaluated the role of this natural aridity and xeric gradient on edaphic microbial community structure and function in the Namib desert. A total of 80 individual soil samples were collected at 10-km intervals along a 190-km transect from the fog-dominated western coastal region to the eastern desert boundary. Seventeen physicochemical parameters were measured for each soil sample. Soil parameters reflected the three a priori defined climatic/xeric zones along the transect ("fog," "low rain," and "high rain"). Microbial community structures were characterized by terminal restriction fragment length polymorphism fingerprinting and shotgun metaviromics, and their functional capacities were determined by extracellular enzyme activity assays. Both microbial community structures and activities differed significantly between the three xeric zones. The deep sequencing of surface soil metavirome libraries also showed shifts in viral composition along the xeric transect. While bacterial community assembly was influenced by soil chemistry and stochasticity along the transect, variations in community "function" were apparently tuned by xeric stress.

Range and niche shifts in response to past climate change in the desert horned lizard (Phrynosoma platyrhinos)

PubMed Central

Jezkova, Tereza; Jaeger, Jef R.; Oláh-Hemmings, Viktória; Jones, K. Bruce; Lara-Resendiz, Rafael A.; Mulcahy, Daniel G.; Riddle, Brett R.

2015-01-01

During climate change, species are often assumed to shift their geographic distributions (geographic ranges) in order to track environmental conditions – niches – to which they are adapted. Recent work, however, suggests that the niches do not always remain conserved during climate change but shift instead, allowing populations to persist in place or expand into new areas. We assessed the extent of range and niche shifts in response to the warming climate after the Last Glacial Maximum (LGM) in the desert horned lizard (Phrynosoma platyrhinos), a species occupying the western deserts of North America. We used a phylogeographic approach with mitochondrial DNA sequences to approximate the species range during the LGM by identifying populations that exhibit a genetic signal of population stability versus those that exhibit a signal of a recent (likely post-LGM) geographic expansion. We then compared the climatic niche that the species occupies today with the niche it occupied during the LGM using two models of simulated LGM climate. The genetic analyses indicated that P. platyrhinos persisted within the southern Mojave and Sonoran deserts throughout the latest glacial period and expanded from these deserts northwards, into the western and eastern Great Basin, after the LGM. The climatic niche comparisons revealed that P. platyrhinos expanded its climatic niche after the LGM towards novel, warmer and drier climates that allowed it to persist within the southern deserts. Simultaneously, the species shifted its climatic niche towards greater temperature and precipitation fluctuations after the LGM. We concluded that climatic changes at the end of the LGM promoted both range and niche shifts in this lizard. The mechanism that allowed the species to shift its niche remains unknown, but phenotypic plasticity likely contributes to the species ability to adjust to climate change. PMID:27231410

Range and niche shifts in response to past climate change in the desert horned lizard (Phrynosoma platyrhinos).

PubMed

Jezkova, Tereza; Jaeger, Jef R; Oláh-Hemmings, Viktória; Jones, K Bruce; Lara-Resendiz, Rafael A; Mulcahy, Daniel G; Riddle, Brett R

2016-05-01

During climate change, species are often assumed to shift their geographic distributions (geographic ranges) in order to track environmental conditions - niches - to which they are adapted. Recent work, however, suggests that the niches do not always remain conserved during climate change but shift instead, allowing populations to persist in place or expand into new areas. We assessed the extent of range and niche shifts in response to the warming climate after the Last Glacial Maximum (LGM) in the desert horned lizard ( Phrynosoma platyrhinos ), a species occupying the western deserts of North America. We used a phylogeographic approach with mitochondrial DNA sequences to approximate the species range during the LGM by identifying populations that exhibit a genetic signal of population stability versus those that exhibit a signal of a recent (likely post-LGM) geographic expansion. We then compared the climatic niche that the species occupies today with the niche it occupied during the LGM using two models of simulated LGM climate. The genetic analyses indicated that P. platyrhinos persisted within the southern Mojave and Sonoran deserts throughout the latest glacial period and expanded from these deserts northwards, into the western and eastern Great Basin, after the LGM. The climatic niche comparisons revealed that P. platyrhinos expanded its climatic niche after the LGM towards novel, warmer and drier climates that allowed it to persist within the southern deserts. Simultaneously, the species shifted its climatic niche towards greater temperature and precipitation fluctuations after the LGM. We concluded that climatic changes at the end of the LGM promoted both range and niche shifts in this lizard. The mechanism that allowed the species to shift its niche remains unknown, but phenotypic plasticity likely contributes to the species ability to adjust to climate change.

Biological soil crusts as an integral component of desert environments

USGS Publications Warehouse

Belnap, Jayne; Weber, Bettina

2013-01-01

The biology and ecology of biological soil crusts, a soil surface community of mosses, lichens, cyanobacteria, green algae, fungi, and bacteria, have only recently been a topic of research. Most efforts began in the western U.S. (Cameron, Harper, Rushforth, and St. Clair), Australia (Rogers), and Israel (Friedmann, Evenari, and Lange) in the late 1960s and 1970s (e.g., Friedmann et al. 1967; Evenari 1985reviewed in Harper and Marble 1988). However, these groups worked independently of each other and, in fact, were often not aware of each other’s work. In addition, biological soil crust communities were seen as more a novelty than a critical component of dryland ecosystems. Since then, researchers have investigated many different aspects of these communities and have shown that although small to microscopic, biological soil crusts are critical in many ecological processes of deserts. They often cover most of desert soil surfaces and substantially mediate inputs and outputs from desert soils (Belnap et al. 2003). They can be a large source of biodiversity for deserts, as they can contain more species than the surrounding vascular plant community (Rosentreter 1986). These communities are important in reducing soil erosion and increasing soil fertility through the capture of dust and the fixation of atmospheric nitrogen and carbon into forms available to other life forms (Elbert et al. 2012). Because of their many effects on soil characteristics, such as external and internal morphological characteristics, aggregate stability, soil moisture, and permeability, they also affect seed germination and establishment and local hydrological cycles. Covering up to 70% of the surface area in many arid and semi-arid regions around the world (Belnap and Lange 2003), biological soil crusts are a key component within desert environments.

Correlation of the major late Jurassic —early Tertiary low- and highstand cycles of south-west Egypt and north-west Sudan

NASA Astrophysics Data System (ADS)

Wycisk, Peter

1994-12-01

The mainly continental deposits of northwest Sudan and south-west Egypt have been correlated with coeval shallow marine and marine deposits in northern Egypt along a north-south running cross-section, based on surface and subsurface data. The palaeodepth curve of northern Egypt illustrates the gradual seal-level rise, reaching its maximum during the Late Cretaceous with conspicuous advances during the Aptian and late Cenomanian. A general highstand is also recorded during the Campanian-Maastrichtian in north-west Sudan. A detailed facies correlation is given for the Aptian and late Cenomanian highstand in western Egypt. The correlation of the Cenomanian Bahariya and Maghrabi formations displays short-term relative sealevel fluctuations. The interpretation illustrates the extensiveness of related erosional processes in the hinterland, partly intensified by temporarily uplift of the Uweinat-Aswan High in the south. Regional uplift and constant erosion took place in south-west Egypt during Coniacian and Santonian times. The regional stratigraphic gaps and uncertain interpretation of the Bahariya Uplift are induced by the influence of the Trans-African Lineament, especially during the Late Cretaceous. Low-stand fluvial sheet sandstones characterized by non-cyclic sequence development and high facies stability occur, especially in the Neocomian and early Turonian. During the Barremian and Albian, fluvial architecture changes to more cyclic fluvial sequences and increasing soil formation, due to increasing subsidence, more humid climatic conditions and the generally rising sea level, culminating in the extensive shallow marine Abu Ballas and Maghrabi formations.

Unusual dominance by desert pupfish (Cyprinodon macularius) in experimental ponds within the Salton Sea Basin

USGS Publications Warehouse

Saiki, Michael K.; Martin, Barbara A.; Anderson, Thomas W.

2011-01-01

In October 2006, months after shallow experimental ponds in the Salton Sea Basin were filled with water from the Alamo River and Salton Sea, fish were observed in several ponds, although inlets had been screened to exclude fish. During October 2007November 2009, nine surveys were conducted using baited minnow traps to document species and relative abundance of fish. Surveys yielded 3,620 fish representing five species. Desert pupfish (Cyprinodon macularius), the only native species encountered, was the most numerous and comprised >93% of the catch. Nonnative species included western mosquitofish (Gambusia affinis, 4.1%), sailfin molly (Poecilia latipinna, 2.8%), and tilapia (a mixture of hybrid Mozambique tilapia Oreochromis mossambicus ?? O. urolepis and redbelly tilapia Tilapia zillii, <0.1%). Dominance by desert pupfish, which persisted over our 2 years of study, was unusual because surveys conducted in nearby agricultural drains yielded relatively few desert pupfish.

Egypt: Beyond Pharaohs, Feluccas and Fellahin.

ERIC Educational Resources Information Center

Holt, Evelyn R.

In a random study of five middle school social studies textbooks available for adoption in the state of Indiana in 1984, great variation in the treatment of Egypt was noted. Coverage of contemporary history was incomplete in all cases. All texts dealt with Egypt's ancient history, but what was reported was questionable. Only one text addressed in…

Effects of added Zn, Ni and Cd on desert shrubs grown in desert soil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patel, P.M.; Wallace, A.; Romney, E.M.

1980-01-01

Desert shrubs - Ambrosia dumosa, Lycium andersonii, Larrea tridenata, and Ephedra nevadensis wre grown in a glasshouse in desert (calcarous) soil with different levels of added Zn, Ni, and Cd. The objective was to study effects of the metals on growth and yield and uptake and translocation of metals in desert plant species which are common in the Mojave Desert (areas of Nevada and southeast California). Zinc and Cd considerably decreased yields of all four species. Yields of E. nevadensis were increased by Ni at 250 and 500 mg/kg applied to desert soil. Ephedra nevadensis was more tolerant of Nimore » than were the other three desert shrubs. Some interactions were observed among various elements: manganese concentration was increased in shrubs by Zn. Particularly, application of Ni reduced the concentrations of Zn and Mn over the control.« less

Introduction and domestication of woody plants for sustainable agriculture in desert areas

NASA Astrophysics Data System (ADS)

Shelef, Oren; Soloway, Elaine; Rachmilevitch, Shimon

2014-05-01

High radiation in hot deserts results in high salinity, especially in irrigated fields. Whenever not treated properly, this salinization may harm crops and eventually bring to soil destruction, field abandonment, or literally desertification. Furthermore, the range of crops that can be grown commercially in hot deserts is limited (Nerd et al. 1990). With the globalization of the last century, Introduction of exotic species for commercial use became more accessible. However, these attempts may involve extreme land changes including establishment of potential invasive species. Therefore domestication of native species should be preferred rather than introduction of exotics. In the last six years we did first steps of domesticating several native species, searching for commercial potential (pharmaceutics, food, biomass for energy and desalination of constructed wetlands). We studied aspects of desert plant physiology in drought and saline conditions. We wish to share the knowledge we gained regarding the physiology and commercial potential of the following desert plant species: 1) Bassia indica is an annual halophyte. We proposed to use it for salt phytoremediation in constructed wetlands for wastewater treatment and as feed for livestock; 2) Commiphora gileadensis is considered as the balm tree of Judea, praised for its use as holy oil and in perfumes but also considered as a cure for many diseases. C. gileadensis today grows naturally in southwest Arabia and Somaliland. We found anti-proliferative and apoptotic effect of C. gileadensis extracts on several human cancer cells. Ben Gurion University of the Negev has patented these findings. 3) Artemisia sieberi and A. judaica are both known for various therapeutic traits. While studying effects of irrigation intensity on these traits, some allopathic characters were discovered. 4) Fichus palmate disappeared from Israel, but remind in neighbouring Jordan and Egypt. This tree may serve as a robust stand for fig

Spatial and temporal changes in desertification in the southern region of the Tengger Desert from 1973 to 2009

NASA Astrophysics Data System (ADS)

Guan, Qingyu; Guan, Wenqian; Yang, Jing; Zhao, Shilei; Pan, Baotian; Wang, Lei; Song, Na; Lu, Min; Li, Fuchun

2017-07-01

The sandy land in the southern region of the Tengger Desert is adjacent to cities and towns, and land desertification poses a threat to the livelihood and production of local residents. To determine dynamic changes in local desertification, five periods (1973, 1987, 1992, 2001, and 2009) of remote sensing data are studied by remote sensing (RS) and geographic information system (GIS). The desert contraction area is primarily centered around three units (Wuwei, Gulang, and Jingtai) and nearby regions of Zhongwei City. The primary desert expansion areas include the west side of Helan Mountain (WSHM), the Central Mountainous Area (CMA), and the eastern and western Zhongwei units far from towns. From 1973 to 2009, the degree of change in the contracting part of the primary desert expansion unit showed an increasing trend; in brief, most of the desert (especially after 2001) has been developing in a direction in which desertification has been gradually controlled. The primary desert expansion areas are less affected by human activity, but they are primarily controlled by natural factors (especially wind and terrain). The desert contraction areas occur around the towns and nearby regions with frequent human activity; desertification is primarily controlled by human factors. With rapid economic development (especially after 2000), the scale of the cultivated area, town, and ecological protection engineering has gradually expanded, and the latter two are primarily built on a previous desert, which is the root cause of the reduction in the desert areas around the towns and the shrinkage toward north of border. Therefore, reasonable and effective human activity in the southern region of the Tengger Desert is playing a crucial role in preventing desertification.

Sex pheromone of the saturniid moth, Hemileuca burnsi, from the western Mojave Desert of California.

PubMed

McElfresh, J Steven; Millar, Jocelyn G

2008-09-01

The sex pheromone blend of Hemileuca burnsi (Lepidoptera: Saturniidae) from the western Mojave Desert was determined to be a combination of (10E,12Z)-hexadecadien-1-yl acetate (E10,Z12-16:Ac), (10E,12Z)-hexadecadien-1-ol (E10,Z12-16:OH), (10E,12E)-hexadecadien-1-yl acetate (E10,E12-16:Ac), and hexadecyl acetate (16:Ac). (10E,12Z)-Hexadecadienal (E10,Z12-16:Ald) was tentatively identified in pheromone gland extracts based on electroantennographic responses and, when added to the above blend, it enhanced trap captures at low doses. The mean ratio of the compounds in extracts of pheromone glands was 100:23:232:14:0.4 (E10,Z12-16:Ac: E10,E12-16:Ac: 16:Ac: E10,Z12-16:OH: E10,Z12-16:Ald). Field trials indicated that although E10,Z12-16:Ac and E10,Z12-16:OH were essential for attraction, the two-component blend was not attractive by itself. Addition of the three other compounds was necessary for maximum attraction, rendering this the most complicated pheromone blend described for a Hemileuca species to date. Similarities between the sex pheromone of H. burnsi and that of the allopatric Hemileuca electra electra and differences between the blends of H. burnsi and that of the sympatric H. electra mojavensis support a case for reproductive character displacement in the pheromone communication channel of H. electra.

African Historical Religions: A Conceptual and Ethnical Foundation for "Western Religions."

ERIC Educational Resources Information Center

Alexander, E. Curtis

This paper attempts to set the record straight with regard to the following assumptions: (1) the Africans of the antiquities of Ethiopia and Egypt were black people; and (2) the same black people developed the foundation that provides the basis for the so-called major Western religions of Judaism, Christianity, and Islam. There are two parts to…

Lut Desert, Iran

NASA Technical Reports Server (NTRS)

1981-01-01

Iran is a large country with several desert regions. In the Dasht-E-Lut (Lut Desert) (30.5N, 58.5E) an area known as Namak-Zar, about 100 miles east of the city of Kerman, is at the center of this photograph. Some of the world's most prominent Yardangs (very long, parallel ridges and depressions) have been wind eroded in these desert dry lake bed sediments. At the left of the photo is a large field of sand dunes at right angles to the wind.

Livestock grazing and the desert tortoise in the Mojave Desert

USGS Publications Warehouse

Oldemeyer, John L.

1994-01-01

A large part of the Mojave Desert is not in pristine condition, and some current conditions can be related to past grazing-management practices. No information could be found on densities of the desert tortoise (Gopherus agassizii) or on vegetative conditions of areas that had not been grazed to allow managers a comparison of range conditions with data on tortoises. Experimental information to assess the effect of livestock grazing on tortoises is lacking, and researchers have not yet examined whether the forage that remains after grazing is sufficient to meet the nutritional needs of desert tortoises.

Evolution of rattlesnakes (Viperidae; Crotalus) in the warm deserts of western North America shaped by Neogene vicariance and Quaternary climate change.

PubMed

Douglas, Michael E; Douglas, Marlis R; Schuett, Gordon W; Porras, Louis W

2006-10-01

During Pleistocene, the Laurentide ice sheet rearranged and diversified biotic distributions in eastern North America, yet had minimal physical impact in western North America where lineage diversification is instead hypothesized to result from climatic changes. If Pleistocene climatic fluctuations impacted desert species, the latter would reflect patterns of restricted gene flow concomitant with indications of demographic bottlenecks. Accordingly, molecular evidence for refugia should be present within these distributions and for subsequent range expansions as conditions improved. We sought answers to these questions by evaluating mitochondrial DNA (mtDNA) sequences from four species of rattlesnakes [Crotalus mitchellii (speckled rattlesnake), Crotalus cerastes (sidewinder), Crotalus tigris (tiger rattlesnake), Crotalus ruber (red diamond rattlesnake)] with distributions restricted to desert regions of southwestern North America. We inferred relationships using parsimony and maximum likelihood, tested intraspecific clades for population expansions, applied an isolation-with-migration model to determine bi-directional migration rates (m) among regions, and inferred divergence times for species and clades by applying a semiparametric penalized likelihood approach to our molecular data. Evidence for significant range expansion was present in two of eight regions in two species (Crotalus mitchellii pyrrhus, C. tigris region north). Two species (C. cerastes, C. mitchellii) showed a distribution concomitant with northward displacement of Baja California from mainland México, followed by vicariant separation into subclades. Effects of Pleistocene climate fluctuations were found in the distributions of all four species. Three regional diversification patterns were identified: (i) shallow genetic diversity that resulted from Pleistocene climatic events (C. tigris, C. ruber); (ii) deep Pleistocene divisions indicating allopatric segregation of subclades within refugia (C

Desert Scrublands

USGS Publications Warehouse

Jones, L.L.C.; Halama, K.J.; Lovich, R.E.

2016-01-01

Desert scrublands comprise the lower to mid-elevation portions of four different ecosystems including the Chihuahuan, Great Basin, Mojave and Sonoran Deserts. Together the area inside their outer boundaries includes over 8% of the surface area of the United States. Despite significant differences in the flora and fauna of these bioregions they all share the common trait of being arid shrub-steppe ecosystems, receiving, on average, less than 254 mm of rain per year. The austere nature of these landscapes belies their significant biodiversity, the amazing behavioral and physiological adaptations of the biota, and the fragility of the ecosystems to human disturbances. For example, the Mojave Desert alone has at least 250 species of ephemeral plants, mostly winter annuals, and up to 90% are endemic.

Distribution of desert varnish in Arizona

NASA Technical Reports Server (NTRS)

Elvidge, Christopher D.

1989-01-01

Desert varnish is the dark coat of clay and ferromanganese oxides developed on exposed rock surfaces in arid regions. It forms from the accretion of material from windblown dust. The distribution of desert varnish was mapped in Arizona. It was discovered that desert varnish could be mapped on a regional scale. Well developed desert varnish is common on stable rock surfaces in areas having alkaline soils and less than about 25 cm of annual precipitation. Rock surfaces in areas having more than 40 cm of annual precipitation are generally devoid of desert varnish. An experiment was conducted with varnished desert pavement stone. The stones were broken in half and half was set on a roof in central Illinois from April until October. Removed from the alkaline desert environment, it only took seven months for the varnish to develop an eroded appearance. This experiment graphically illustrates the dependency of desert varnish on alkalinity. In this context, the zones of eroded desert varnish in Arizona indicate that the area of active desert varnish formation has fluctuated, expanding in drier times and contracting/eroding in wetter times.

The rural and the rotund? A critical interpretation of food deserts and rural adolescent obesity in the Canadian context.

PubMed

McPhail, Deborah; Chapman, Gwen E; Beagan, Brenda L

2013-07-01

Resting on the notion that rural spaces are "food deserts," rural adolescents are increasingly regarded as a "problem population" in Western obesity narratives. Using qualitative data gleaned from interviews with 51 teenage participants from rural areas across Canada, this paper focuses on the ways in which obesity is constructed as a rural disease in the Canadian context, demonstrating in particular how discourses of food deserts and related rural obesity rely on classist imaginings of obesity as a working-class embodiment. The paper will further question the understanding of the rural as a food desert, showing the ways in which rural teens acquire fresh, healthy foods in part through an informal economy of food growing and sharing. Copyright © 2013 Elsevier Ltd. All rights reserved.

[The wild boar of Egypt].

PubMed

Manlius, N; Gautier, A

1999-07-01

The wild boar, Sus scrofa, is not a typical member of the Egyptian wild fauna, although it appears to have lived in the Nile Delta and other suitable regions in the north of the country. However, historic populations were probably of mixed origin, including feral domestic pigs. It is incorrect, as is sometimes still done, to include the wild boar in the iconographic bestiary of Ancient Egypt and assume that the domestic pigs of Ancient Egypt derive from local wild boars.

Review of Parasitic Zoonoses in Egypt

PubMed Central

Youssef, Ahmed I.; Uga, Shoji

2014-01-01

This review presents a comprehensive picture of the zoonotic parasitic diseases in Egypt, with particular reference to their relative prevalence among humans, animal reservoirs of infection, and sources of human infection. A review of the available literature indicates that many parasitic zoonoses are endemic in Egypt. Intestinal infections of parasitic zoonoses are widespread and are the leading cause of diarrhea, particularly among children and residents of rural areas. Some parasitic zoonoses are confined to specific geographic areas in Egypt, such as cutaneous leishmaniasis and zoonotic babesiosis in the Sinai. Other areas have a past history of a certain parasitic zoonoses, such as visceral leishmaniasis in the El-Agamy area in Alexandria. As a result of the implementation of control programs, a marked decrease in the prevalence of other zoonoses, such as schistosomiasis and fascioliasis has been observed. Animal reservoirs of parasitic zoonoses have been identified in Egypt, especially in rodents, stray dogs and cats, as well as vectors, typically mosquitoes and ticks, which constitute potential risks for disease transmission. Prevention and control programs against sources and reservoirs of zoonoses should be planned by public health and veterinary officers based on reliable information from systematic surveillance. PMID:24808742

Gujarat, Western India

NASA Technical Reports Server (NTRS)

2002-01-01

Extremely high sediment loads are delivered to the Arabian Sea along the coast of Pakistan (upper left) and western India. In the case of the Indus River (far upper left) this sedimentation, containing large quantities of desert sand, combines with wave action to create a large sand-bar like delta. In the arid environment, the delta lacks much vegetation, but contains numerous mangrove-lined channels. This true-color image from May 2001 shows the transition from India's arid northwest to the wetter regions farther south along the coast. The increase in vegetation along the coast is brought about by the moisture trapping effect of the Western Ghats Mountain Range that runs north-south along the coast. Heavy sediment is visible in the Gulf of Kachchh (north) and the Gulf of Khambhat(south), which surround the Gujarat Peninsula.

Joint Egypt/United States report on Egypt/United States cooperative energy assessment. Volume 5 of 5 Vols. Annexes 11--13

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-04-01

The principal features of the existing environment of Egypt are characterized and the main problem areas identified in Annex 11. The environmental, health, and associated social issues that must be considered in choosing from among the options available to Egypt for meeting projected future energy needs are identified. The environmental impacts associated with these options are discussed and observations are made of alternte ways to minimize environmental insults. Annex 12, Manpower, analyzes the energy-related manpower situation of Egypt. Manpower education and training resources of Egypt; the existing manpower base of Egypt; manpower needs of the energy strategies; a comparison ofmore » manpower needs and existing manpower base; and the underlying economic and social factors that will make Egypt energy facility development very difficult to plan and execute are discussed. Annex 13 summarizes a preliminary analysis of the capital, labor, materials, and equipment resources required to implement alternative Egyptian energy futures and documents the assessment of several Egyptian energy development programs selected by the DOE. It egins with brief overviews of the ESPM model and data base. It then describes the method by which the system was adapted to Egyptian conditions and the results of this modification. The comparison Case energy development program is described, followed by a summary of ESPM-derived facility and resource requirements. Finally, the sensitivity of these results to several alternative energy strategies is illustrated.« less

Knowledge, attitudes and practices of adolescents in Upper Egypt on gender-based violence, with a focus on early girls' marriage.

PubMed

Mahmoud, Alaa El Dine H

2015-09-01

A large proportion of the female population all over the world, particularly in developing countries, experience some form of gender-based violence (GBV) during their life. Early marriage, a form of GBV, is particularly highly prevalent in rural Upper Egypt. The aim of the current study was to assess the knowledge, attitudes and practices (KAP) of adolescents in Upper Egypt on domestic GBV, with a focus on early girls' marriage. The study was a cross-sectional descriptive household survey targeting 400 randomly selected adolescent boys and girls aged 11-16 years from five villages of Minya Governorate in Upper Egypt. The proportion of interviewed adolescents who could identify certain practices as forms of GBV was relatively low: the identified practices were mainly deprivation of work (9.0%), deprivation of inheritance (3.3%), arbitrary neglect and desertion (2.8%), and preventing from visiting relatives (0.5%). Abusive sexual behavior was not identified by any of the study participants as a form of domestic GBV. A total of 112 boys (56.0%) reported that they have been perpetrators in domestic GBV events at least once and 118 girls (59.0%) reported that they have been actual victims of domestic GBV. An overall 65.6% of study participants could correctly identify the legal age of marriage as 18 years, yet only 22.0% identified earlier ages of marriage as a form of domestic GBV. The vast majority of girls and boys reported that they would not agree to get married before the age of 18 years (91.0 and 87.0%, respectively). Adolescents in Upper Egypt demonstrated a less than satisfactory knowledge about the forms of GBV. Although early girls' marriage was not universally recognized by adolescents as a form of domestic GBV, they demonstrated satisfactory knowledge about the legal age of marriage, as well as a tendency to abandon the practice. Establishing a community-based awareness program for adolescents of both sexes about GBV with a focus on early girls' marriage is

Egypt`s first subsea completion: A Gulf of Suez case history

DOE Office of Scientific and Technical Information (OSTI.GOV)

El Hawary, A.; Hoffman, J.G.

1996-06-01

A case history of the Gulf of Suez Petroleum Co.`s (Gupco) first subsea completion is provided. The first completion was for Well GS 373-2, a previously drilled and tested exploration well located in the south portion of the gulf of Suez. Subsea technology was used to economically justify development of this one-well marginal field, which was discovered in 1978. Traditional methods proved to be too costly for development, therefore application of a low-cost subsea tree was used to capture the resources. In the Gulf of Suez, many fields have been discovered but have not been developed because of low reserves.more » These marginal projects can have a profound impact on the revenue and shareholder value if an economic method is used to exploit these opportunities. Platform installation was not feasible because of reserve size, hence the well has remained abandoned until recently. This paper presents a summarized look at subsea completion technology. The cost comparison of traditional development methods will be made, given the local cost structure in Egypt. The application of this technology has some limitations and constraints that will be discussed in the paper. Furthermore, the actual field installation of Egypt`s first subsea tree will be summarized. Also included is a discussion on simple remote controls and offshore installation operations.« less

Magnetic measurements with fluxgate 3-components magnetometers in archaeology. Multi-sensor device and associated potential field operators for large scale to centimetre investigations on the 1st millennium BC site of Qasr ʿAllam in the western desert of

NASA Astrophysics Data System (ADS)

Gavazzi, Bruno; Alkhatib-Alkontar, Rozan; Munschy, Marc; Colin, Frédéric; Duvette, Catherine

2016-04-01

Fluxgate 3-components magnetometers allow vector measurements of the magnetic field. Moreover, they are the magnetometers measuring the intensity of the magnetic field with the lightest weight and the lowest power consumption. Vector measurements make them the only kind of magnetometer allowing compensation of magnetic perturbations due to the equipment carried with the magnetometer. Fluxgate 3-components magnetometers are common in space magnetometry and in aero-geophysics but are never used in archaeology due to the difficulty to calibrate them. This problem is overcome by the use of a simple calibration and compensation procedure on the field developed initially for space research (after calibration and compensation, rms noise is less than 1 nT). It is therefore possible to build a multi-sensor (up to 8) and georeferenced device for investigations at different scales down to the centimetre: because the locus of magnetic measurements is less than a cubic centimetre, magnetic profiling or mapping can be performed a few centimetres outside magnetized bodies. Such an equipment is used in a context of heavy sediment coverage and uneven topography on the 1st millennium BC site of Qasr ʿAllam in the western desert of Egypt. Magnetic measurements with a line spacing of 0.5 m allow to compute a magnetic grid. Interpretation using potential field operators such as double reduction to the pole and fractional vertical derivatives reveals a widespread irrigation system and a vast cultic facility. In some areas, magnetic profiling with a 0.1 m line spacing and at 0.1 m above the ground is performed. Results of interpretations give enough proof to the local authorities to enlarge the protection of the site against the threatening progression of agricultural fields.

The Geology of the Ka'u Desert, Hawaii as a Mars Analog

NASA Astrophysics Data System (ADS)

Craddock, R. A.; Irwin, R. P.; Williams, R.; Swanson, D.; Howard, A. D.; Quantin, C.; Kuzmin, R.; Zimbelman, J. R.

2005-12-01

The Ka'u Desert is located on the western flank of Kilauea volcano on the Big Island of Hawaii. It is a desert because it receives little annual rainfall (about 150 mm/yr) but also because it is subjected to constant outgassing from Kilauea, which creates a harsh, acidic environment. Near the summit of Kilauea the Ka'u Desert is characterized by the Keanakako'i tephra deposit, which is several meters deep thinning out to a discontinuous deposit 1.5 km (1 mile) towards the center of the desert. The deposit itself has been incised by a number of gullies that are flat-floored and terminate in a series of amphitheater-shaped plunge pools. Most of the interior desert contains undulating weathered lava flows, extensive deposits of sand, and several more recent lava flows and volcanic edifices. The southern portion of the desert is bounded by the Hilina Pali fault scarp, which is 500 m (1,500 ft) above the nearby Pacific Ocean and contains a complex series of outwash plains, alluvial fans, and debris flows. We will present a summary of the geology of the Ka'u Desert. Contrary to published interpretations, we will present evidence that the Keanakako'i was not emplaced by two separate catastrophic eruption events but rather by two distinct eruption episodes that included multiple eruption events often interrupted by long hiatuses. Despite the morphology of the gullies contained on the Keanakako'i we will present evidence that the gullies were formed exclusively by surface runoff and not groundwater sapping, including quantitative estimates about the large amounts of discharge that occur during extreme storms. We will also present analyses of the sand deposits and determine the likely provenance of these materials. For the first time, we will also describe alluvial fans and mass wasting features on Hilina Pali and show evidence that they are part of poorly integrated channel system that originates in the Keanakako'i tephra. The Ka'u Desert represents a good Mars analog

Mirages in the Desert: Theorizing Western Muslim Identity across 60 Years

ERIC Educational Resources Information Center

El-Sherif, Lucy

2016-01-01

Theorizations on Western Muslim identity that are multi-layered and grounded in actual Western Muslim experiences are hard to find. Two exceptions to this are "The Road to Mecca" by Muhammad Asad (1954/2005), and "Islam is a Foreign Country" by Zareena Grewal (2014), rich texts that span across six decades. Asad's classic…

Status of fertility control in Egypt.

PubMed

Hefnawi, F I

1982-01-01

The concern for fertility control is not alien to the cultural and religious heritage of Egypt. Historically, Egyptian interest in fertility dates to the Pharoahs. Contraceptive recipes written at least 15-18 centuries B.C. have been found. Romans may have borrowed some of the more effective methods from Egypt when it became part of the Roman Empire as evidenced by the decline in size of aristocratic Roman families at the beginning of the Christian era. Muslim conquerors of Egypt encouraged fertility control. In the 9th century differences of opinion about the legality of contraception appeared among the interpreters of Islamic law. Some methods found in the writings of Muslim doctors as al-Razi and Avicenna still survive in the folk medicine of Egypt. In modern times use of barrier methods of contraception were encouraged by family planning organizations in Egypt. The medical profession was not deeply involved since these methods did not require much medical assistance. In 1936 a religiouss verdict declared contraception to be a lawful act of Islam. National programs in family planning in the 1960's encouraged the use of the Lippes Loop IUD. The medical problem of blood loss associated with the IUD caused anxiety because of the high incidence of anemia in the female Egyptian population. There was also a cultural limitation on the wide use of the IUD. "Spotting" due to the IUD resulted in females being ritually unclean and therefore unfit to pray or observe the Islamic fast. The Pill, initially favored caused complications due to its effect on breast milk which is the universal source of nutrition for infants in Egypt. Replacement of the Pill by depo-provera injections during the post partum period of lactation is a practical solution. Permanent sterilization is limited to females and only performed when medically indicated. Abortion is illegal and permitted only as a therapeutic measure.

Sequence stratigraphy of the Lower Cenomanian Bahariya Formation, Bahariya Oasis, Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Catuneanu, O.; Khalifa, M. A.; Wanas, H. A.

2006-08-01

The Lower Cenomanian Bahariya Formation corresponds to a second-order depositional sequence that formed within a continental shelf setting under relatively low-rate conditions of positive accommodation (< 200 m during 3-6 My). This overall trend of base-level rise was interrupted by three episodes of base-level fall that resulted in the formation of third-order sequence boundaries. These boundaries are represented by subaerial unconformities (replaced or not by younger transgressive wave ravinement surfaces), and subdivide the Bahariya Formation into four third-order depositional sequences. The construction of the sequence stratigraphic framework of the Bahariya Formation is based on the lateral and vertical changes between shelf, subtidal, coastal and fluvial facies, as well as on the nature of contacts that separate them. The internal (third-order) sequence boundaries are associated with incised valleys, which explain (1) significant lateral changes in the thickness of incised valley fill deposits, (2) the absence of third-order highstand and even transgressive systems tracts in particular areas, and (3) the abrupt facies shifts that may occur laterally over relatively short distances. Within each sequence, the concepts of lowstand, transgressive and highstand systems tracts are used to explain the observed lateral and vertical facies variability. This case study demonstrates the usefulness of sequence stratigraphic analysis in understanding the architecture and stacking patterns of the preserved rock record, and helps to identify 13 stages in the history of base-level changes that marked the evolution of the Bahariya Oasis region during the Early Cenomanian.

PHYLOGEOGRAPHY OF BUFO PUNCTATUS: LONG TERM EVOLUTION WITHIN THE WARM DESERTS OF NORTH AMERICA AND LATE QUATERNARY RANGE SHIFTING

EPA Science Inventory

Bufo punctatus, the red-spotted toad, is a widespread anuran of the warm-desert regions of western North America. This distribution makes this species ideal for evaluating biotic response to geotectonically and climatically mediated episodes of landscape transformation (e.g., ear...

Lyme Disease Agent in Egypt?

DTIC Science & Technology

1989-02-01

reverse if necessary and identify by block number) CIELD CPzOUP ISUB-GRO0UP Lyme disease; Borrelia spp. ; Treponema pallidumv ARSTRACTPatients...AD-A240 332 CC PUBLICATION REPORT O!t2 TAh 1583 By~ 65189-90 r ! tb ut I ui LYME DISEASE AGENT IN EGYPT? ’’ Ave Richard L. Habarberger’, Niel T...a dilution of Lyme disease agent in Egypt? 1:100 with the prototype strain B-31 ofB. burgdorferi. Results indicated that none of the 16 meningitis or

Trophic relationships of small nonnative fishes in a natural creek and several agricultural drains flowing into the Salton Sea, and their potential, effects on the endangered desert pupfish

USGS Publications Warehouse

Martin, Barbara A.; Saiki, Michael K.

2009-01-01

This study was conducted to characterize trophic relationships of small nonnative fishes and to determine if predation by these fishes contributes to the decline of desert pupfish (Cyprinodon macularius), an endangered cyprinodont on the verge of extinction. We sampled 403 hybrid Mozambique tilapias (Oreochromis mossambica by O. urolepis), 107 redbelly tilapias (Tilapia zillii), 32 longjaw mudsuckers (Gillkhthys mirabilis), 182 western mosquitofish (Gambusia affinis), 222 sailfin mollies (Poecilia latipinna), 63 shortfin mollies (Poecilia mexicana), and 235 porthole livebearers (Poecilurpsis gracilis) from a natural creek and four agricultural drains during September 1999- December 2001. Evidence of piscivory was in gastrointestinal contents of 14 hybrid Mozambique tilapias, 3 redbelly tilapias, 10 longjaw mudsuckers, 8 western mosquitofish, 2 sailfin mollies, and 8 porthole livebearers. Although digestion often was too advanced for identification of fishes consumed by nonnative fishes, remains of desert pupfish were in gastrointestinal contents of a longjaw mudsucker. Our findings, along with Field evidence from other studies that inverse relationships exist between abundances of desert pupfish and nonnative species, are consistent with the hypothesis that predation by nonnative species is contributing to decline of desert pupfish. We suspect that competitive interactions with nonnative fishes might also adversely affect abundance of desert pupfish.

Views of Ancient Egypt. Teacher's Guide. School Arts: Looking/Learning.

ERIC Educational Resources Information Center

Downs, Linda; Brenner, Carla

This teaching guide discusses ancient Egyptian culture, the lithographs made by Napoleon's scientists in 1798-99 to study and record every aspect of Egypt, the world's subsequent fascination with Egypt, ancient Egyptian architecture, Egyptian writing, and archeologists' illustrations of Egypt. The guide suggests activities for elementary school,…

Global Diversity of Desert Hypolithic Cyanobacteria.

PubMed

Lacap-Bugler, Donnabella C; Lee, Kevin K; Archer, Stephen; Gillman, Len N; Lau, Maggie C Y; Leuzinger, Sebastian; Lee, Charles K; Maki, Teruya; McKay, Christopher P; Perrott, John K; de Los Rios-Murillo, Asunción; Warren-Rhodes, Kimberley A; Hopkins, David W; Pointing, Stephen B

2017-01-01

Global patterns in diversity were estimated for cyanobacteria-dominated hypolithic communities that colonize ventral surfaces of quartz stones and are common in desert environments. A total of 64 hypolithic communities were recovered from deserts on every continent plus a tropical moisture sufficient location. Community diversity was estimated using a combined t-RFLP fingerprinting and high throughput sequencing approach. The t-RFLP analysis revealed desert communities were different from the single non-desert location. A striking pattern also emerged where Antarctic desert communities were clearly distinct from all other deserts. Some overlap in community similarity occurred for hot, cold and tundra deserts. A further observation was that the producer-consumer ratio displayed a significant negative correlation with growing season, such that shorter growing seasons supported communities with greater abundance of producers, and this pattern was independent of macroclimate. High-throughput sequencing of 16S rRNA and nif H genes from four representative samples validated the t-RFLP study and revealed patterns of taxonomic and putative diazotrophic diversity for desert communities from the Taklimakan Desert, Tibetan Plateau, Canadian Arctic and Antarctic. All communities were dominated by cyanobacteria and among these 21 taxa were potentially endemic to any given desert location. Some others occurred in all but the most extreme hot and polar deserts suggesting they were relatively less well adapted to environmental stress. The t-RFLP and sequencing data revealed the two most abundant cyanobacterial taxa were Phormidium in Antarctic and Tibetan deserts and Chroococcidiopsis in hot and cold deserts. The Arctic tundra displayed a more heterogenous cyanobacterial assemblage and this was attributed to the maritime-influenced sampling location. The most abundant heterotrophic taxa were ubiquitous among samples and belonged to the Acidobacteria, Actinobacteria, Bacteroidetes

Global Diversity of Desert Hypolithic Cyanobacteria

PubMed Central

Lacap-Bugler, Donnabella C.; Lee, Kevin K.; Archer, Stephen; Gillman, Len N.; Lau, Maggie C.Y.; Leuzinger, Sebastian; Lee, Charles K.; Maki, Teruya; McKay, Christopher P.; Perrott, John K.; de los Rios-Murillo, Asunción; Warren-Rhodes, Kimberley A.; Hopkins, David W.; Pointing, Stephen B.

2017-01-01

Global patterns in diversity were estimated for cyanobacteria-dominated hypolithic communities that colonize ventral surfaces of quartz stones and are common in desert environments. A total of 64 hypolithic communities were recovered from deserts on every continent plus a tropical moisture sufficient location. Community diversity was estimated using a combined t-RFLP fingerprinting and high throughput sequencing approach. The t-RFLP analysis revealed desert communities were different from the single non-desert location. A striking pattern also emerged where Antarctic desert communities were clearly distinct from all other deserts. Some overlap in community similarity occurred for hot, cold and tundra deserts. A further observation was that the producer-consumer ratio displayed a significant negative correlation with growing season, such that shorter growing seasons supported communities with greater abundance of producers, and this pattern was independent of macroclimate. High-throughput sequencing of 16S rRNA and nifH genes from four representative samples validated the t-RFLP study and revealed patterns of taxonomic and putative diazotrophic diversity for desert communities from the Taklimakan Desert, Tibetan Plateau, Canadian Arctic and Antarctic. All communities were dominated by cyanobacteria and among these 21 taxa were potentially endemic to any given desert location. Some others occurred in all but the most extreme hot and polar deserts suggesting they were relatively less well adapted to environmental stress. The t-RFLP and sequencing data revealed the two most abundant cyanobacterial taxa were Phormidium in Antarctic and Tibetan deserts and Chroococcidiopsis in hot and cold deserts. The Arctic tundra displayed a more heterogenous cyanobacterial assemblage and this was attributed to the maritime-influenced sampling location. The most abundant heterotrophic taxa were ubiquitous among samples and belonged to the Acidobacteria, Actinobacteria, Bacteroidetes

Gender, Sibship Composition, and Education in Egypt

ERIC Educational Resources Information Center

Tfaily, Rania

2016-01-01

This article examines the relationship between gender, sibship, and education over time in Egypt, focusing on how the number, sex, and birth order configuration of siblings affected boys' and girls' education during 1991-2008, a period characterized by significant social and economic changes in Egypt. This study disaggregates schooling into…

Does protection of desert tortoise habitat generate other ecological benefits in the Mojave Desert?

Treesearch

Matthew L. Brooks

2000-01-01

This paper summarizes the ecological effects of fenced habitat protection for the desert tortoise (Gopherus agassizii) at the Desert Tortoise Research Natural Area in the Mojave Desert. The following were higher inside than outside the natural area: (1) annual and perennial plant biomass, cover, diversity and dominance by natives, (2) soil seed...

Populations at risk: conservation genetics of kangaroo mice (Microdipodops) of the Great Basin Desert.

PubMed

Andersen, John J; Portnoy, David S; Hafner, John C; Light, Jessica E

2013-08-01

The Great Basin Desert of western North America has experienced frequent habitat alterations due to a complex biogeographic history and recent anthropogenic impacts, with the more recent alterations likely resulting in the decline of native fauna and flora. Dark (Microdipodops megacephalus) and pallid (M. pallidus) kangaroo mice are ecological specialists found within the Great Basin Desert and are potentially ideal organisms for assessing ecosystem health and inferring the biogeographic history of this vulnerable region. Herein, newly acquired nuclear-encoded microsatellite loci were utilized to assess patterns of variation within and among spatially discrete groups of kangaroo mice and to evaluate gene flow, demographic trends, and genetic integrity. Results confirm that there are at least three genetically distinct units within M. megacephalus and two such units within M. pallidus. The three units of M. megacephalus appear to have different demographic histories, with effectively no gene flow among them since their divergence. Similarly, the two units of M. pallidus also appear to have experienced different demographic histories, with effectively no gene exchange. Contemporary effective population sizes of all groups within Microdipodops appear to be low (<500), suggesting that each genetic lineage may have difficulty coping with changing environmental pressures and hence may be at risk of extirpation. Results of this study indicate that each Microdipodops group should be recognized, and therefore managed, as a separate unit in an effort to conserve these highly specialized taxa that contribute to the diversity of the Great Basin Desert ecosystem. The Great Basin Desert of western North America has experienced frequent habitat alterations due to a complex biogeographic history and recent anthropogenic impacts, with the more recent alterations likely resulting in the decline of native fauna and flora. Herein, newly acquired nuclear-encoded microsatellite

Urology and the scientific method in ancient Egypt.

PubMed

Gordetsky, Jennifer; O'Brien, Jeanne

2009-03-01

To examine the practice of urology in ancient Egypt using various sources, including the Edwin Smith and Ebers Papyri. The sources of knowledge of ancient Egyptian medicine include medical papyri, paleopathology, art, and hieroglyphic carvings. A brief overview of the medical system in ancient Egypt was completed, in addition to an examination of the training and specialization of the physician in the ancient world. Urologic diseases treated in ancient Egypt and some of the first documented urologic surgeries are presented. Finally, we studied the role of the physician-priest and the intertwined use of religion and magic in ancient Egyptian medicine. The same medical conditions urologists treat in the office today were methodically documented thousands of years ago. Medical papyri show evidence that the ancient Egyptians practiced medicine using a scientific method based on the clinical observation of disease. This has been exemplified by the Edwin Smith Surgical Papyrus, a collection of surgical cases that gives a diagnosis, treatment, and prognosis for each ailment, and the discovery of medical specialization in ancient Egypt, giving us perhaps the world's first urologists. Intertwined with the scientific method was also the rich mysticism and religion of ancient Egypt, which were integral components of the healing process. We present an overview of the practice of urology in ancient Egypt, in terms of both pharmacologic and surgical intervention, as well as with a look into the religion of medicine practiced at that time.

Impact of the geological structures on the groundwater potential using geophysical techniques in West Bani Mazar area, El Minia - Western Desert, Egypt

NASA Astrophysics Data System (ADS)

Mahmoud, Hussein Hosni; Kotb, Adel Diab Mohammed

2017-06-01

Establishment of the new agricultural projects in west Bani Mazar area, El Minia, Egypt needs a good knowledge about groundwater. Groundwater serves as the unique source of water supplies in the study area. Vertical Electrical Sounding technique is a convenient tool for groundwater exploration. This technique was utilized to illustrate the geoelectric succession, vertical and spatial extensions of the encountered layers, depth to water bearing layers and the structures affecting these layers. Profiling technique was carried out along a grid pattern using different half current electrode spacings (150 m, 300 m and 500 m) to clarify changes in resistivity values throughout the study area at different depths. Geoelectric layers B1 and B2 of the saturated zone are suitable for groundwater extraction in the study area. The resistivity values of the geoelectric layer B1 decrease towards the West direction, they decrease from 23.0 Ωm to 16.0 Ωm; and its thicknesses increase towards the SE direction from 12.0 m to 18.0 m. Whereas, the resistivity values of the geoelectric layer B2 decrease towards the NW direction from 40.0 Ωm to 26.5 Ωm; and its thicknesses vary from 34.0 m to 40.0 m. The depths to the upper surface of the water bearing layer B1 increase towards the NW direction from 44.0 m to 89.4 m. Based on the results obtained from the Vertical Electrical Soundings, four two-dimensional resistivity imaging profiles were measured at the selected sites. These 2-D resistivity profiles aim to determine depths to the water bearing layers, their thicknesses and the shallow structure. The inverted models of these profiles matched with the geoelectric sequence at these sites. In addition, a normal fault is detected at the northwestern part of the study area. According to the results obtained from this study it is clear that the groundwater in the area under consideration is occurred in the fractured limestone layers that belong to Eocene Age. Resistivity values of the

Aquaporins in desert rodent physiology.

PubMed

Pannabecker, Thomas L

2015-08-01

Desert rodents face a sizeable challenge in maintaining salt and water homeostasis due to their life in an arid environment. A number of their organ systems exhibit functional characteristics that limit water loss above that which occurs in non-desert species under similar conditions. These systems include renal, pulmonary, gastrointestinal, nasal, and skin epithelia. The desert rodent kidney preserves body water by producing a highly concentrated urine that reaches a maximum osmolality nearly three times that of the common laboratory rat. The precise mechanism by which urine is concentrated in any mammal is unknown. Insights into the process may be more apparent in species that produce highly concentrated urine. Aquaporin water channels play a fundamental role in water transport in several desert rodent organ systems. The role of aquaporins in facilitating highly effective water preservation in desert rodents is only beginning to be explored. The organ systems of desert rodents and their associated AQPs are described. © 2015 Marine Biological Laboratory.

Ancient Egypt.

ERIC Educational Resources Information Center

Evers, Virginia

This four-week fourth grade social studies unit dealing with religious dimensions in ancient Egyptian culture was developed by the Public Education Religion Studies Center at Wright State University. It seeks to help students understand ancient Egypt by looking at the people, the culture, and the people's world view. The unit begins with outlines…

Investigation of dust storms entering Western Iran using remotely sensed data and synoptic analysis.

PubMed

Boloorani, Ali D; Nabavi, Seyed O; Bahrami, Hosain A; Mirzapour, Fardin; Kavosi, Musa; Abasi, Esmail; Azizi, Rasoul

2014-01-01

One of the natural phenomena which have had considerable impacts on various regions of the world, including Iran, is "dust storm". In recent years, this phenomenon has taken on new dimensions in Iran and has changed from a local problem to a national issue. This study is an attempt to investigate the formation of the dust storms crossing the Western Iran. To find the sources of the dust storms entering Iran, first we examine three determined dust paths in the region and their temporal activities, using MODIS satellite images. Then, four regions were identified as dust sources through soil, land cover and wind data. Finally, atmospheric analyses are implemented to find synoptic patterns inducing dust storms. Source 1 has covered the region between the eastern banks of Euphrates and western banks of Tigris. Source 2 is in desert area of western and south-western Iraq. Finally source 3 is bounded in eastern and south-eastern deserts of Saudi Arabia called Rub-Al-Khali desert, or Empty Quarter. Moreover, south-eastern part of Iraq (source 4) was also determined as a secondary source which thickens the dust masses originating from the above mentioned sources. The study of synoptic circulations suggests that the dust storms originating from source 1 are formed due to the intense pressure gradient between the low-pressure system of Zagros and a high-pressure cell formed on Mediterranean Sea. The dust events in sources 2 and 3 are outcomes of the atmospheric circulations dominant in the cold period of the year in mid-latitudes.

Management of Disused Radioactive Sealed Sources in Egypt - 13512

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mohamed, Y.T.; Hasan, M.A.; Lasheen, Y.F.

The future safe development of nuclear energy and progressive increasing use of sealed sources in medicine, research, industry and other fields in Egypt depends on the safe and secure management of disused radioactive sealed sources. In the past years have determined the necessity to formulate and apply the integrated management program for radioactive sealed sources to assure harmless and ecological rational management of disused sealed sources in Egypt. The waste management system in Egypt comprises operational and regulatory capabilities. Both of these activities are performed under legislations. The Hot Laboratories and Waste Management Center HLWMC, is considered as a centralizedmore » radioactive waste management facility in Egypt by law 7/2010. (authors)« less

Desert and desertification in Iran

NASA Astrophysics Data System (ADS)

Bahrami, M.

2009-04-01

One of the greatest environmental concerns in Iran as in other arid and semiarid countries is the transformation of once productive, or marginally productive, land to deteriorated land and soil unable to support plants and animals. Because the land becomes barren and dry, the process is described as desertification, which occurs as a sequence of events. The area of deserts in Iran is about 340,000 Km2 (less than one fifth of its total area), of which 100,000 Km2 is being used for some cultivation, 120,000 Km2 is subjected to moving sands about 40 % of which is active sand dunes. Most of features and processes usual in world famous deserts are also observed in Iran: low precipitation, high evaporation, poor or lack of vegetation, saline and alkaline soils, low population and small and sparse oases. The deserts of Iran are generally classified in the subtropical, warm, arid and semiarid group, but the effect and presence of some geographical and geoclimatical factors such as height, vicinity to Indian Ocean and so on do some changes in climatic conditions and geographical features causing some local and regional differences in them. Geographically, two groups of deserts have been known in Iran: (1) Coastal deserts which, like a ribbon with variable width, stretch from extreme southeast to extreme southwest, at the north parts of Oman Sea and Persian Gulf. One important feature of these deserts is relatively high humidity which differentiates them from other deserts. This causes an increase in vegetation coverage and hence a decrease in eolian erosion and also a dominance of chemical weathering to that of physical. (2) internal deserts, which rest in central, eastern and southeastern plateau of the country and in independent and semi dependent depressions. This situation, which is due to the surrounding high mountains, blocks humidity entry and causes the aridity of these deserts. Wind as a dominant process in the area causes deflated features such as Reg (desert

76 FR 66354 - DesertXpress Enterprises, LLC and DesertXpress HSR Corporation-Construction and Operation...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-26

... DEPARTMENT OF TRANSPORTATION Surface Transportation Board [Docket No. FD 35544] DesertXpress Enterprises, LLC and DesertXpress HSR Corporation-- Construction and Operation Exemption--in Victorville, CA... requirements of 49 U.S.C. 10901 for DesertXpress Enterprises, LLC and its subsidiary (DXE) to build and operate...

Microsatellite analysis of Fasciola spp. in Egypt.

PubMed

Dar, Yasser; Amer, Said; Courtioux, Bertrand; Dreyfuss, Gilles

2011-12-01

Recently, the topic of diversity in Fasciola population in Egypt is controversial. The present study was performed to study the genetic diversity of isolated flukes based on microsatellites markers. Fasciola worms were collected from different hosts and geographical locations in Egypt. Control samples of Fasciola hepatica from France as well as Fasciola gigantica from Cameroon were included in the study. Collected flukes were identified morphologically and subjected for analysis using four microsatellite markers. Results of microsatellite profile (FM1 and FM2) proved that both species of Fasciola are distributed in Egypt irrespective of geographical location and host. Nevertheless, the microsatellite profile of some analyzed loci (FM2 and FM3) proved that Egyptian flukes showed more alleles compared to the reference ones. Differences of microsatellite profile in Egyptian isolates than that of corresponding reference samples indicate the remarkable diversity of these isolates. The present results highlighted the utility of microsatellite profile to discriminate between Fasciola species and to elucidate the diversity within the species. To our knowledge, this is the first time to study microsatellite polymorphism in Fasciola populations in Egypt.

Water movement through a thick unsaturated zone underlying an intermittent stream in the western Mojave Desert, southern California, USA

USGS Publications Warehouse

Izbicki, J.A.; Radyk, J.; Michel, R.L.

2000-01-01

Previous studies indicated that small amounts of recharge occur as infiltration of intermittent streamflow in washes in the upper Mojave River basin, in the western Mojave Desert, near Victorville, California. These washes flow only a few days each year after large storms. To reach the water table, water must pass through an unsaturated zone that is more than 130 m thick. Results of this study, done in 1994-1998, showy that infiltration to depths below the root zone did not occur at control sites away from the wash. At these sites, volumetric water contents were as low as 0.01 and water potentials (measured as the combination of solute and matric potentials using a water activity meter) were as negative as -14,000 kPa. Water-vapor movement was controlled by highly negative solute potentials associated with the accumulation of soluble salts in the unsaturated zone. Highly negative matric potentials above and below the zone of maximum solute accumulation result from movement of water vapor toward the highly negative solute potentials at that depth. The ??18O and ??D (delta oxygen-18 and delta deuterium) isotopic composition of water in coarse-grained deposits plots along a Rayleigh distillation line consistent with removal of water in coarse-grained layers by vapor transport. Beneath Oro Grande Wash, water moved to depths below the root zone and, presumably, to the water table about 130 m below land surface. Underneath Oro Grande Wash, volumetric water contents were as high as 0.27 and water potentials (measured as matric potential using tensiometers) were between -1.8 and -50 kPa. On the basis of tritium data, water requires at least 180-260 years to infiltrate to the water table. Clay layers impede the downward movement of water. Seasonal changes in water vapor composition underneath the wash are consistent with the rapid infiltration of a small quantity of water to great depths and subsequent equilibration of vapor with water in the surrounding material. It may be

Impact of the pathogen Pyrenophora semeniperda on Bromus tectorum seedbank dynamics in North American cold deserts

Treesearch

S. E. Meyer; D. Quinney; D. L. Nelson; J. Weaver

2007-01-01

Bromus tectorum is a dominant winter annual weed in cold deserts of western North America. We followed patterns of seed carry-over and abundance of the pathogen Pyrenophora semeniperda over 5 years at B. tectorum-dominated shadscale (Atriplex confertifolia) and sagebrush (Artemisia tridentata) sites in southern Idaho. We hypothesised that more seeds could potentially...

Astronomy Education Challenges in Egypt

NASA Astrophysics Data System (ADS)

El Fady Beshara Morcos, Abd

2015-08-01

One of the major challenges in Egypt is the quality of education. Egypt has made significant progress towards achieving the Education for All and the Millennium Development Goals (MDGs). Many associations and committees as education reform program and education support programs did high efforts in supporting scientific thinking through the scientific clubs. The current state of astronomical education in Egypt has been developed. Astronomy became a part in both science and geography courses of primary, preparatory and secondary stages. Nowadays the Egyptian National Committee for Astronomy, put on its shoulders the responsibility of revising of astronomy parts in the education courses, beside preparation of some training programs for teachers of different stages of educations, in collaboration with ministry of education. General lectures program has been prepared and started in public places , schools and universities. Many TV and Radio programs aiming to spread astronomical culture were presented. In the university stage new astronomy departments are established and astrophysics courses are imbedded in physics courses even in some private universities.

Evolutionary hotspots in the Mojave Desert

USGS Publications Warehouse

Vandergast, Amy G.; Inman, Richard D.; Barr, Kelly R.; Nussear, Kenneth E.; Esque, Todd C.; Hathaway, Stacie A.; Wood, Dustin A.; Medica, Philip A.; Breinholt, Jesse W.; Stephen, Catherine L.; Gottscho, Andrew D.; Marks, Sharyn B.; Jennings, W. Bryan; Fisher, Robert N.

2013-01-01

Genetic diversity within species provides the raw material for adaptation and evolution. Just as regions of high species diversity are conservation targets, identifying regions containing high genetic diversity and divergence within and among populations may be important to protect future evolutionary potential. When multiple co-distributed species show spatial overlap in high genetic diversity and divergence, these regions can be considered evolutionary hotspots. We mapped spatial population genetic structure for 17 animal species across the Mojave Desert, USA. We analyzed these in concurrence and located 10 regions of high genetic diversity, divergence or both among species. These were mainly concentrated along the western and southern boundaries where ecotones between mountain, grassland and desert habitat are prevalent, and along the Colorado River. We evaluated the extent to which these hotspots overlapped protected lands and utility-scale renewable energy development projects of the Bureau of Land Management. While 30–40% of the total hotspot area was categorized as protected, between 3–7% overlapped with proposed renewable energy project footprints, and up to 17% overlapped with project footprints combined with transmission corridors. Overlap of evolutionary hotspots with renewable energy development mainly occurred in 6 of the 10 identified hotspots. Resulting GIS-based maps can be incorporated into ongoing landscape planning efforts and highlight specific regions where further investigation of impacts to population persistence and genetic connectivity may be warranted.

Tech Talk for Social Studies Teachers: Ancient Egypt.

ERIC Educational Resources Information Center

Pahl, Ronald H.

1998-01-01

Presents an annotated bibliography of 10 Web sites concerning ancient Egypt that have materials appropriate for social studies classes. Includes virtual tours of Egypt and specific temples, explorations of the pyramids, archaeological and geographic information, and information on the Egyptian "Book of the Dead." (MJP)

Opportunities for woody crop production using treated wastewater in Egypt

Treesearch

Ronald S. Jr. Zalesny; Steven R. Evett; Nabil F. Kandil; Chris Soriano; John A. Stanturf

2009-01-01

The Nile River provides nearly 97% of Egypt’s freshwater supply. Egypt's share of Nile waters is allocated according to international treaty obligations and is fixed at 55.5 billion cubic meters annually. As a result, Egypt will not be able to meet increasing water demand using freshwater from the Nile and has been developing wastewater reuse strategies to meet...

Water Management Strategy in Assessing the Water Scarcity in Northern Western Region of Nile Delta, Egypt

NASA Astrophysics Data System (ADS)

Mabrouk, Badr; Arafa, Salah; Gemajl, Khaled

2015-04-01

Sustainable development in the Nile Delta of Egypt is retarded by serious environmental problems, where land-use and land-cover of the region are subjected to continuous changes; including shoreline changes either by erosion or accretion, subsidence of the delta, as well as by sea level rise due to climate change. The current research attempts to; (1) study the vulnerability of the northern western region of the Nile Delta coastal zone to climate change/sea level rise while setting basic challenges, review adaptation strategies based on adaptation policy framework, and highlight recommended programs for preparedness to climate change, (2) study the scarcity of water resources in the area of study with review of the socioeconomic impacts and the critical need of establishing desalination plants with new standards assessing the environmental situation and population clusters, and (3) monitor of the brine water extracted from the desalination plants and injected to subsurface strata. This monitoring process is divided into 3 main directions: 1) studying the chemical characteristics of water extracted from the water desalinations plants qualitatively and quantitatively. 2) mapping the subsurface of which that brine water will be injected to it and the flow directions and effects using resistivity data, and 3) using GIS and suitable numerical models in order to study the effect, volume, flow of the brine water and its long term environmental impacts on the area. The results indicate that the area is particularly vulnerable to the impact of SLR, salt water intrusion, the deterioration of coastal tourism and the impact of extreme dust storms. This in turn will directly affect the agricultural productivity and human settlements in coastal zones. The paper presents different scenarios for water management and recommends the most suitable scenarios in order to establish a core for water management strategy in the region according to existing socio-economic and environmental

Mitigation options for the industrial sector in Egypt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gelil, I.A.; El-Touny, S.; Korkor, H.

1996-12-31

Though its contribution to the global Greenhouse gases emission is relatively small, Egypt has signed and ratified the United Nations Framework Convention on Climate Change (UN FCCC) and has been playing an active role in the international efforts to deal with such environmental challenges. Energy efficiency has been one of the main strategies that Egypt has adopted to improve environmental quality and enhance economic competitiveness. This paper highlights three initiatives currently underway to improve energy efficiency of the Egyptian industry. The first is a project that has been recently completed by OECP to assess potential GHG mitigation options available inmore » Egypt`s oil refineries. The second initiative is an assessment of GHG mitigation potential in the Small and Medium size Enterprises (SME) in the Mediterranean city of Alexandria. The third one focuses on identifying demand side management options in some industrial electricity consumers in the same city.« less

Genomic footprints of dryland stress adaptation in Egyptian fat-tail sheep and their divergence from East African and western Asia cohorts.

PubMed

Mwacharo, Joram M; Kim, Eui-Soo; Elbeltagy, Ahmed R; Aboul-Naga, Adel M; Rischkowsky, Barbara A; Rothschild, Max F

2017-12-15

African indigenous sheep are classified as fat-tail, thin-tail and fat-rump hair sheep. The fat-tail are well adapted to dryland environments, but little is known on their genome profiles. We analyzed patterns of genomic variation by genotyping, with the Ovine SNP50K microarray, 394 individuals from five populations of fat-tail sheep from a desert environment in Egypt. Comparative inferences with other East African and western Asia fat-tail and European sheep, reveal at least two phylogeographically distinct genepools of fat-tail sheep in Africa that differ from the European genepool, suggesting separate evolutionary and breeding history. We identified 24 candidate selection sweep regions, spanning 172 potentially novel and known genes, which are enriched with genes underpinning dryland adaptation physiology. In particular, we found selection sweeps spanning genes and/or pathways associated with metabolism; response to stress, ultraviolet radiation, oxidative stress and DNA damage repair; activation of immune response; regulation of reproduction, organ function and development, body size and morphology, skin and hair pigmentation, and keratinization. Our findings provide insights on the complexity of genome architecture regarding dryland stress adaptation in the fat-tail sheep and showcase the indigenous stocks as appropriate genotypes for adaptation planning to sustain livestock production and human livelihoods, under future climates.

Observation of local cloud and moisture feedbacks over high ocean and desert surface temperatures

NASA Technical Reports Server (NTRS)

Chahine, Moustafa T.

1995-01-01

New data on clouds and moisture, made possible by reanalysis of weather satellite observations, show that the atmosphere reacts to warm clusters of very high sea surface temperatures in the western Pacific Ocean with increased moisture, cloudiness, and convection, suggesting a negative feedback limiting the sea surface temperature rise. The reverse was observed over dry and hot deserts where both moisture and cloudiness decrease, suggesting a positive feedback perpetuating existing desert conditions. In addition, the observations show a common critical surface temperature for both oceans and land; the distribution of atmospheric moisture is observed to reach a maximum value when the daily surface temperatures approach 304 +/- 1 K. These observations reveal complex dynamic-radiative interactions where multiple processes act simultaneously at the surface as well as in the atmosphere to regulate the feedback processes.

Safsaf Oasis, Egypt

NASA Image and Video Library

1998-04-06

These images show two views of a region of south-central Egypt. On the left is an optical image from NASA Landsat Thematic Mapper, and on the right is a radar image from NASA Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar SIR-C/X-SAR.

Cumulative biological impacts framework for solar energy projects in the California Desert

USGS Publications Warehouse

Davis, Frank W.; Kreitler, Jason R.; Soong, Oliver; Stoms, David M.; Dashiell, Stephanie; Hannah, Lee; Wilkinson, Whitney; Dingman, John

2013-01-01

This project developed analytical approaches, tools and geospatial data to support conservation planning for renewable energy development in the California deserts. Research focused on geographical analysis to avoid, minimize and mitigate the cumulative biological effects of utility-scale solar energy development. A hierarchical logic model was created to map the compatibility of new solar energy projects with current biological conservation values. The research indicated that the extent of compatible areas is much greater than the estimated land area required to achieve 2040 greenhouse gas reduction goals. Species distribution models were produced for 65 animal and plant species that were of potential conservation significance to the Desert Renewable Energy Conservation Plan process. These models mapped historical and projected future habitat suitability using 270 meter resolution climate grids. The results were integrated into analytical frameworks to locate potential sites for offsetting project impacts and evaluating the cumulative effects of multiple solar energy projects. Examples applying these frameworks in the Western Mojave Desert ecoregion show the potential of these publicly-available tools to assist regional planning efforts. Results also highlight the necessity to explicitly consider projected land use change and climate change when prioritizing areas for conservation and mitigation offsets. Project data, software and model results are all available online.

Alexandria, Egypt

NASA Image and Video Library

2000-11-20

ISS01-E-5025 (November 2000) --- This nadir view of Alexandria, Egypt, was provided by a digital still camera image down linked from the International Space Station to flight controllers in Houston. Alexandria (Al Iskandariya) occupies a T-shaped peninsula and strip of land separating the Mediterranean from Lake Mariout. According to NASA scientists studying the Expedition One photo collection, the town was originally built upon a mole (stone breakwater) called Heptastadium, which joined the island of Pharos to the mainland. Since then, the scientists say, sedimentary deposits have added considerably to the width of the mole. Since 1905, when the city’s 370 thousand inhabitants lived in an area of about four square kilometers between the two harbors, the city (population 4 million) has grown beyond its medieval walls and now occupies an area of about 300 square kilometers. The Mahmudiya Canal, connecting Alexandria with the Nile, runs to the south of the city and, by a series of locks, enters the harbor of the principal port of Egypt (note ships). The reddish and ochre polygons west of Lake Mariout are salt-evaporation, chemical-storage, and water-treatment ponds within the coastal lagoon.

Regional variations in the provenance of desert sedimentary systems: An example from the Paraná Basin, Brazil

NASA Astrophysics Data System (ADS)

Bertolini, G.; Marques, J. C.; Hartley, A. J.; Scherer, C.; Macdonald, D.; Hole, M.; Stipp Basei, M. A. A. S.; Frantz, J. C.; Rosa, A. A. S.

2017-12-01

Large desert basins (>1.000.000 km²) are likely to contain sediment derived from different sources due to variations in factors such as wind direction, sand availability, and sediment influx. Provenance analysis is key to determining sediment sources and to constrain the nature of the sediment fill in desert basins. The Cretaceous Botucatu Desert dunefield extended across a large area of the interior of the SW Gondwana and was then buried by extensive lava flows that covered the active erg. The onset of volcanic activity triggered climatic and topographic variations that changed the depositional setting, however, the aeolian system remained active during this time period. Twenty samples were collected along the southern border of the basin (Brazil and Uruguay). Heavy mineral (HM) and petrographic analyses indicate very mature sediment, with a high ZTR index and quartz dominated sandstones. Despite the regularity of high ZTR index, garnet input occurs in eastern samples. Ten samples were selected for MC-LA-ICP-MS zircon dating with the aim of comparing pre- and syn-volcanic sandstones. More than 800 detrital zircons (DZ) were analyzed and the results allowed the identification of 5 relevant peaks interpreted as: 1) Choiyoi volcanism; 2) Famatian Cycle; 3) Brazilian Cycle (BC); 4) Grenvillian Cycle (GC); 5) Transamazonic Cycle. The DZ ages from the pre and syn-volcanic sandstones show no significant variation. However, when comparing the provenance between the eastern and western areas, samples from the eastern border show a major BC contribution (61%), while the western samples contain 40%. The GC contribution is more significant in the western part of the basin (>18%), contrasting with 6% in eastern samples. The main conclusions are: 1) the DZ record reveals a distinct signature for sedimentary sources; 2) climatic and topographic changes caused by the onset of volcanic activity had no impact on DZ populations; 3) heavy mineral types are very similar in all

Environmental processes and spectral reflectance characteristics associated with soil erosion in desert fringe regions

NASA Technical Reports Server (NTRS)

Jacobberger, P. A.

1986-01-01

Two Thematic Mapper (TM) scenes were acquired. A scene was acquired for the Bahariya, Egypt field area, and one was acquired covering the Okavango Delta site. Investigations at the northwest Botswana study sites have concentrated upon a system of large linear (alab) dunes possessing an average wavelength of 2 kilometers and an east-west orientation. These dunes exist to the north and west of the Okavango Swamp, the pseudodeltaic end-sink of the internal Okavango-Cubango-Cuito drainage network. One archival scene and two TM acquisitions are on order, but at present no TM data were acquired for the Tombouctou/Azaouad Dunes, Mali. The three areas taken together comprise an environmental series ranging from hyperarid to semi-arid, with desertization processes operational or incipient in each. The long range goal is to predict normal seasonal variations, so that aperiodic spectral changes resulting from soil erosion, vegetation damage, and associated surface processes would be distinguishable as departures from the norm.

Avian Influenza A(H5N1) Virus in Egypt.

PubMed

Kayali, Ghazi; Kandeil, Ahmed; El-Shesheny, Rabeh; Kayed, Ahmed S; Maatouq, Asmaa M; Cai, Zhipeng; McKenzie, Pamela P; Webby, Richard J; El Refaey, Samir; Kandeel, Amr; Ali, Mohamed A

2016-03-01

In Egypt, avian influenza A subtype H5N1 and H9N2 viruses are enzootic in poultry. The control plan devised by veterinary authorities in Egypt to prevent infections in poultry focused mainly on vaccination and ultimately failed. Recently, widespread H5N1 infections in poultry and a substantial increase in the number of human cases of H5N1 infection were observed. We summarize surveillance data from 2009 through 2014 and show that avian influenza viruses are established in poultry in Egypt and are continuously evolving genetically and antigenically. We also discuss the epidemiology of human infection with avian influenza in Egypt and describe how the true burden of disease is underestimated. We discuss the failures of relying on vaccinating poultry as the sole intervention tool. We conclude by highlighting the key components that need to be included in a new strategy to control avian influenza infections in poultry and humans in Egypt.

Avian Influenza A(H5N1) Virus in Egypt

PubMed Central

Kandeil, Ahmed; El-Shesheny, Rabeh; Kayed, Ahmed S.; Maatouq, Asmaa M.; Cai, Zhipeng; McKenzie, Pamela P.; Webby, Richard J.; El Refaey, Samir; Kandeel, Amr; Ali, Mohamed A.

2016-01-01

In Egypt, avian influenza A subtype H5N1 and H9N2 viruses are enzootic in poultry. The control plan devised by veterinary authorities in Egypt to prevent infections in poultry focused mainly on vaccination and ultimately failed. Recently, widespread H5N1 infections in poultry and a substantial increase in the number of human cases of H5N1 infection were observed. We summarize surveillance data from 2009 through 2014 and show that avian influenza viruses are established in poultry in Egypt and are continuously evolving genetically and antigenically. We also discuss the epidemiology of human infection with avian influenza in Egypt and describe how the true burden of disease is underestimated. We discuss the failures of relying on vaccinating poultry as the sole intervention tool. We conclude by highlighting the key components that need to be included in a new strategy to control avian influenza infections in poultry and humans in Egypt. PMID:26886164

Opportunities for woody crop production using treated wastewater in Egypt

Treesearch

R.S. Zalesny; S.R.  Evett; N.F. Kandil; C.  Soriano; John Stanturf

2011-01-01

The Nile River provides nearly 97% of Egypt’s freshwater supply. Egypt’s share of Nile waters is fixed at 55.5 billion cubic meters annually. As a result, Egypt will not be able to meet increasing water demand using freshwater from the Nile and has been developing non-conventional wastewater reuse strategies to meet future demands. The USAID Mission in Cairo began...

Practical water production from desert air

PubMed Central

Kalmutzki, Markus J.; Kapustin, Eugene A.

2018-01-01

Energy-efficient production of water from desert air has not been developed. A proof-of-concept device for harvesting water at low relative humidity was reported; however, it used external cooling and was not desert-tested. We report a laboratory-to-desert experiment where a prototype using up to 1.2 kg of metal-organic framework (MOF)–801 was tested in the laboratory and later in the desert of Arizona, USA. It produced 100 g of water per kilogram of MOF-801 per day-and-night cycle, using only natural cooling and ambient sunlight as a source of energy. We also report an aluminum-based MOF-303, which delivers more than twice the amount of water. The desert experiment uncovered key parameters pertaining to the energy, material, and air requirements for efficient production of water from desert air, even at a subzero dew point. PMID:29888332

Practical water production from desert air.

PubMed

Fathieh, Farhad; Kalmutzki, Markus J; Kapustin, Eugene A; Waller, Peter J; Yang, Jingjing; Yaghi, Omar M

2018-06-01

Energy-efficient production of water from desert air has not been developed. A proof-of-concept device for harvesting water at low relative humidity was reported; however, it used external cooling and was not desert-tested. We report a laboratory-to-desert experiment where a prototype using up to 1.2 kg of metal-organic framework (MOF)-801 was tested in the laboratory and later in the desert of Arizona, USA. It produced 100 g of water per kilogram of MOF-801 per day-and-night cycle, using only natural cooling and ambient sunlight as a source of energy. We also report an aluminum-based MOF-303, which delivers more than twice the amount of water. The desert experiment uncovered key parameters pertaining to the energy, material, and air requirements for efficient production of water from desert air, even at a subzero dew point.

Hydrogeochemical evolution of inland lakes’ water: A study of major element geochemistry in the Wadi El Raiyan depression, Egypt

PubMed Central

Mohamed, Essam A.; El-Kammar, Ahmed M.; Yehia, Mohamed M.; Abu Salem, Hend S.

2015-01-01

Wadi El Raiyan is a great depression located southwest of Cairo in the Western Desert of Egypt. Lake Qarun, located north of the study area, is a closed basin with a high evaporation rate. The source of water in the lake is agricultural and municipal drainage from the El Faiyum province. In 1973, Wadi El Raiyan was connected with the agricultural wastewater drainage system of the Faiyum province and received water that exceeded the capacity of Lake Qarun. Two hydrogeological regimes have been established in the area: (i) higher cultivated land and (ii) lower Wadi El Raiyan depression lakes. The agricultural drainage water of the cultivated land has been collected in one main drain (El Wadi Drain) and directed toward the Wadi El Raiyan depression, forming two lakes at different elevations (upper and lower). In the summer of 2012, the major chemical components were studied using data from 36 stations distributed over both hydrogeological regimes in addition to one water sample collected from Bahr Youssef, the main source of freshwater for the Faiyum province. Chemical analyses were made collaboratively. The major ion geochemical evolution of the drainage water recharging the El Raiyan depression was examined. Geochemically, the Bahr Youssef sample is considered the starting point in the geochemical evolution of the studied surface water. In the cultivated area, major-ion chemistry is generally influenced by chemical weathering of rocks and minerals that are associated with anthropogenic inputs, as well as diffuse urban and/or agricultural drainage. In the depression lakes, the water chemistry generally exhibits an evaporation-dependent evolutionary trend that is further modified by cation exchange and precipitation of carbonate minerals. PMID:26644942

Jeeps Penetrating a Hostile Desert

ERIC Educational Resources Information Center

Bailey, Herb

2009-01-01

Several jeeps are poised at base camp on the edge of a desert aiming to escort one of them as far as possible into the desert, while the others return to camp. They all have full tanks of gas and share their fuel to maximize penetration. In a friendly desert it is best to leave caches of fuel along the way to help returning jeeps. We solve the…

Egypt Nile delta gas plays take off

DOE Office of Scientific and Technical Information (OSTI.GOV)

Petzet, G.A.

1996-08-26

This paper reviews the exploration and resource potential of Egypt`s Nile delta as a major gas/condensate province. It discusses the various company`s involved in developing these resources and their plans for exploitation. It reviews the drilling in the area and gives a summary of the reservoir geology of the areas. It identifies the major discoveries as they relate to the various reservoirs in the delta area.

Joint Egypt/United States report on Egypt/United States cooperative energy assessment. Volume 1 of 5 Vols. Executive summary, main report and appendices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-04-01

The International Energy Assessment Program between Egypt and the U.S. was formulated from mid-March to mid-July, 1978. The assessment identified energy demand and supply options for Egypt that are consistent with its indigenous energy resources; assessed Egypt's ability to effectively use those options; and identified measures by which Egypt's energy-planning activities could be improved. The assessment addressed all known and potential energy supply options (oil, gas, coal, oil shale, hydroelectric, nuclear power, geothermal, solar, wind, and biomass). Using the Reference Energy System, two future energy supply/demand balances are constructed (for 1985 and the year 2000) and these are compared withmore » a historical (1975) supply/demand balance. The feasibility of each of the options is established in terms of the availability of the required resources and of the processing, conversion, transport, and utilization technology.« less

Influence of structures on drainage patterns in the Tushka region, SW Egypt

NASA Astrophysics Data System (ADS)

Robinson, C. A.; El-Kaliouby, H.; Ghoneim, E.

2017-12-01

Remote sensing (radar, thermal and topographic) and geophysical (Vertical Electrical Sounding and Ground Penetrating Radar) data are used to understand areas with enhanced groundwater potential in deeper aquifer settings between 22°0‧-22°56‧N and 30°21-31°20‧E in the Tushka area of southwest Egypt. The premise is that areas with enhanced groundwater accumulations represent the best locations for agricultural development that is underway in this region and that deeper sources groundwater resources are the most sustainable. New fluvial and structural interpretations emphasize that the desert landscape was produced by fluvial action in the past. The correlation of high drainage and fault densities, coincident with gentle slope, guided sites for geophysical investigation that provides information about the aquifer depth and distribution, and the subsurface distribution of faults. Results confirm the presence of subsurface fault plains and fault zones and potential water aquifers at these locations. Surface environments further demonstrated an abundance of shrubs and cultivatable soils. The new approach therefore is a cost effective and noninvasive technique that can be applied throughout the eastern Sahara to assist in resource management decisions and support the planned agricultural expansion.

Severe mortality of a population of threatened Agassiz’s desert tortoises: the American badger as a potential predator

USGS Publications Warehouse

Emblidge, Patrick G.; Nussear, Ken E.; Esque, Todd C.; Aiello, Christina M.; Walde, Andrew D.

2015-01-01

In the Mojave Desert of the southwestern United States, adult Agassiz’s desert tortoises Gopherus agassizii typically experience high survival, but population declines associated with anthropogenic impacts led to their listing as a threatened Species under the US Endangered Species Act in 1990. Predation of adult tortoises is not often considered a significant threat as they are adapted to deter most predation attempts. Despite these adaptations, some populations have experienced elevated mortality attributed to predators, suggesting that predation pressure may occasionally increase. During the tortoise activity seasons of 2012 and 2013, we observed unsustainably high mortality in 1 of 4 populations of adult desert tortoises (22 and 84%, respectively) in the western Mojave Desert in the vicinity of Barstow, CA. Photographic evidence from trail cameras and examination of carcass condition suggest that American badgers Taxidea taxus— a sometimes cited but unconfirmed predator of adult tortoises — may have been responsible for some of the mortality observed. We discuss the American badger as a plausible predator of a local tortoise population, but recommend further investigation into these events and the impacts such mortality can have on tortoise persistence.

Impacts of off-road vehicles on nitrogen cycles in biological soil crusts: Resistance in different U.S. deserts

USGS Publications Warehouse

Belnap, Jayne

2002-01-01

Biological soil crusts are an important component of desert ecosystems, as they influence soil stability and fertility. This study examined and compared the short-term vehicular impacts on lichen cover and nitrogenase activity (NA) of biological soil crusts. Experimental disturbance was applied to different types of soil in regions throughout the western U.S. (Great Basin, Colorado Plateau, Sonoran, Chihuahuan, and Mojave deserts). Results show that pre-disturbance cover of soil lichens is significantly correlated with the silt content of soils, and negatively correlated with sand and clay. While disturbance appeared to reduce NA at all sites, differences were statistically significant at only 12 of the 26 sites. Cool desert sites showed a greater decline than hot desert sites, which may indicate non-heterocystic cyanobacterial species are more susceptible to disturbance than non-heterocystic species. Sandy soils showed greater reduction of NA as sand content increased, while fine-textured soils showed a greater decline as sand content increased. At all sites, higher NA before the disturbance resulted in less impact to NA post-disturbance. These results may be useful in predicting the impacts of off-road vehicles in different regions and different soils.

Estimating wildfire risk on a Mojave Desert landscape using remote sensing and field sampling

USGS Publications Warehouse

Van Linn, Peter F.; Nussear, Kenneth E.; Esque, Todd C.; DeFalco, Lesley A.; Inman, Richard D.; Abella, Scott R.

2013-01-01

Predicting wildfires that affect broad landscapes is important for allocating suppression resources and guiding land management. Wildfire prediction in the south-western United States is of specific concern because of the increasing prevalence and severe effects of fire on desert shrublands and the current lack of accurate fire prediction tools. We developed a fire risk model to predict fire occurrence in a north-eastern Mojave Desert landscape. First we developed a spatial model using remote sensing data to predict fuel loads based on field estimates of fuels. We then modelled fire risk (interactions of fuel characteristics and environmental conditions conducive to wildfire) using satellite imagery, our model of fuel loads, and spatial data on ignition potential (lightning strikes and distance to roads), topography (elevation and aspect) and climate (maximum and minimum temperatures). The risk model was developed during a fire year at our study landscape and validated at a nearby landscape; model performance was accurate and similar at both sites. This study demonstrates that remote sensing techniques used in combination with field surveys can accurately predict wildfire risk in the Mojave Desert and may be applicable to other arid and semiarid lands where wildfires are prevalent.

Visibility monitoring in the southern California desert for the Department of Defense: Research on operations-limiting visual extinction, RESOLVE protocol

NASA Astrophysics Data System (ADS)

Blumenthal, D.; Trijonis, J.

1984-09-01

A decrease in visibility in the R2508 airspace (in the western Mojave Desert in southern California) since the mid-1940s, when flight test and training facilities were established in this region, is adversely affecting flight and test operations. The Joint Policy and Planning Board (JPPB) of the Department of Defense has initiated studies and discussions of the visibility issue with the goal of developing a management strategy to maintain and optimize the operational capabilities of the test facilities. To identify trends in and sources of visibility degradation in the desert, JPPB initiated two programs: (1) a compilation and review of the historical visibility and air quality data in the California desert region, to be coordinated by the California Desert Air Working Group (CDAWG) and funded by CDAWG participants; and (2) RESearch on Operations-Limiting Visual Extinction (RESOLVE), which involves measuring the visibility at key receptor sites (monitoring stations) in the R2508 region. The report describes the current status of and future plans for the RESOLVE program.

Concentrating Solar Power Projects in Egypt | Concentrating Solar Power |

Science.gov Websites

;alphabetical by project name. You can browse a project profile by clicking on the project name. ISCC Kuraymat NREL Egypt Concentrating solar power (CSP) projects in Egypt are listed belowâ€"

Epidemiology of and Risk Factors for Type 2 Diabetes in Egypt.

PubMed

Hegazi, Refaat; El-Gamal, Mohamed; Abdel-Hady, Nagy; Hamdy, Osama

2015-01-01

Diabetes is a fast-growing health problem in Egypt with a significant impact on morbidity, mortality, and health care resources. Currently, the prevalence of type 2 diabetes (T2D) in Egypt is around 15.6% of all adults aged 20 to 79. To describe the epidemiology, principal causes, associated risk factors, cultural aspects, and challenges that may contribute to the rapid rise in T2D in Egypt. Review of papers in PubMed and relevant gray literature. The International Diabetes Federation (IDF) has identified Egypt as the ninth leading country in the world for the number of patients with T2D. The prevalence of T2D in Egypt was almost tripled over the last 2 decades. This sharp rise could be attributed to either an increased pattern of the traditional risk factors for T2D such as obesity and physical inactivity and change in eating pattern or other risk factors unique to Egypt. These include increased exposure to environmental risk factors like pesticides and increased prevalence of chronic hepatitis C. Prevention, early identification, and effective intervention are integral components of effective T2D care in Egypt. These strategies may reduce the expanding economic burden associated with T2D care. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

When science became Western: historiographical reflections.

PubMed

Elshakry, Marwa

2010-03-01

While thinking about the notion of the "global" in the history of the history of science, this essay examines a related but equally basic concept: the idea of "Western science." Tracing its rise in the nineteenth century, it shows how it developed as much outside the Western world as within it. Ironically, while the idea itself was crucial for the disciplinary formation of the history of science, the global history behind this story has not been much attended to. Drawing on examples from nineteenth-century Egypt and China, the essay begins by looking at how international vectors of knowledge production (viz., missionaries and technocrats) created new global histories of science through the construction of novel genealogies and through a process of conceptual syncretism. Turning next to the work of early professional historians of science, it shows how Arabic and Chinese knowledge traditions were similarly reinterpreted in light of the modern sciences, now viewed as part of a diachronic and universalist teleology ending in "Western science." It concludes by arguing that examining the global emergence of the idea of Western science in this way highlights key questions pertaining to the relation of the history of science to knowledge traditions across the world and the continuing search for global histories of science.

Epidemiology, ecology and gene pool of influenza A virus in Egypt: will Egypt be the epicentre of the next influenza pandemic?

PubMed

Abdelwhab, E M; Abdel-Moneim, Ahmed S

2015-01-01

Outside Asia, Egypt is considered to be an influenza H5N1 epicentre and presents a far greater pandemic risk than other countries. The long-term endemicity of H5N1 and the recent emergence of H9N2 in poultry call attention to the need for unravelling the epidemiology, ecology and highly diverse gene pool of influenza A virus (IAV) in Egypt which is the aim of this review. Isolation of a considerable number of IAV subtypes from several avian and mammalian hosts was described. Co-infections of poultry with H5N1 and H9N2 and subclinical infections of pigs and humans with H1N1 and H5N1 may raise the potential for the reassortment of these viruses. Moreover, the adjustment of IAV genomes, particularly H5N1, to optimize their evolution toward efficient transmission in human is progressing in Egypt. Understanding the present situation of influenza viruses in Egypt will help in the control of the disease and can potentially prevent a possible pandemic.

Epidemiology, ecology and gene pool of influenza A virus in Egypt: Will Egypt be the epicentre of the next influenza pandemic?

PubMed Central

Abdelwhab, EM; Abdel-Moneim, Ahmed S

2015-01-01

Outside Asia, Egypt is considered to be an influenza H5N1 epicentre and presents a far greater pandemic risk than other countries. The long-term endemicity of H5N1 and the recent emergence of H9N2 in poultry call attention to the need for unravelling the epidemiology, ecology and highly diverse gene pool of influenza A virus (IAV) in Egypt which is the aim of this review. Isolation of a considerable number of IAV subtypes from several avian and mammalian hosts was described. Co-infections of poultry with H5N1 and H9N2 and subclinical infections of pigs and humans with H1N1 and H5N1 may raise the potential for the reassortment of these viruses. Moreover, the adjustment of IAV genomes, particularly H5N1, to optimize their evolution toward efficient transmission in human is progressing in Egypt. Understanding the present situation of influenza viruses in Egypt will help in the control of the disease and can potentially prevent a possible pandemic. PMID:25635701

Mojave Desert Ecosystem Program

Science.gov Websites

Toggle navigation logo garis Home About Search Contact About Us History The Mojave Desert Ecosystem providing dynamic, sustainable, land management decision-making at the ecosystem level. Its numerous mission of the Mojave Desert Ecosystem Program is to provide government agencies throughout the Mojave

Magnetic Analysis Techniques Applied to Desert Varnish

NASA Technical Reports Server (NTRS)

Schmidgall, E. R.; Moskowitz, B. M.; Dahlberg, E. D.; Kuhlman, K. R.

2003-01-01

Desert varnish is a black or reddish coating commonly found on rock samples from arid regions. Typically, the coating is very thin, less than half a millimeter thick. Previous research has shown that the primary components of desert varnish are silicon oxide clay minerals (60%), manganese and iron oxides (20-30%), and trace amounts of other compounds [1]. Desert varnish is thought to originate when windborne particles containing iron and manganese oxides are deposited onto rock surfaces where manganese oxidizing bacteria concentrate the manganese and form the varnish [4,5]. If desert varnish is indeed biogenic, then the presence of desert varnish on rock surfaces could serve as a biomarker, indicating the presence of microorganisms. This idea has considerable appeal, especially for Martian exploration [6]. Magnetic analysis techniques have not been extensively applied to desert varnish. The only previous magnetic study reported that based on room temperature demagnetization experiments, there were noticeable differences in magnetic properties between a sample of desert varnish and the substrate sandstone [7]. Based upon the results of the demagnetization experiments, the authors concluded that the primary magnetic component of desert varnish was either magnetite (Fe3O4) or maghemite ( Fe2O3).

Burrow Occupancy Patterns of the Western Burrowing Owl in Southern Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paul D. Greger and Derek B. Hall

Understanding long-term patterns of burrow occupancy for the Western Burrowing Owl (Athene cunicularia hypugaea) is necessary for the conservation of this species, especially in arid, desert ecosystems where burrow occupancy data are lacking. Monthly burrow monitoring was conducted over a 4-year period (1997–2001) in southern Nevada to determine burrow occupancy patterns of Burrowing Owls and to evaluate the effects of burrow type and desert region on burrow occupancy. Burrow occupancy occurred year-round and was most consistent in the Transition region and tended to be lowest in the Mojave Desert region. Peak burrow occupancy occurred during March through May, followed bymore » a gradual decline in occupancy through the summer and fall until January and February, when occupancy was lowest. Occupancy was significantly higher at sites with both culvert and pipe burrows than at sites with earthen burrows in disturbed habitat or earthen burrows in natural habitat. Breeding-season occupancy was not significantly higher in wetter, cooler portions (e.g., Great Basin desert region) of the study area. Results suggest that occupancy is influenced by habitat features—such as suitable burrows in open areas with low vegetation—and climatic regime.« less

No rheumatoid arthritis in ancient Egypt: a reappraisal.

PubMed

Kwiecinski, Jakub; Rothschild, Bruce M

2016-06-01

Antiquity of rheumatoid arthritis (RA) remains controversial, and its origins in Americas or in the Old World are disputed. Proponents of the latter frequently refer to RA in ancient Egypt, but validity of those claims has never been examined. Review of all reported RA cases from ancient Egypt revealed that none of them represent real RA, instead being either examples of changing naming conventions or of imprecise diagnostic criteria. Most cases represented osteoarthritis or spondyloarthropathies. Also review of preserved ancient Egyptian medical writings revealed many descriptions of musculoskeletal disorders, but none of them resembled RA. This suggests that RA was absent in ancient Egypt and supports the hypothesis of the New World origin of RA and its subsequent global spread in the last several centuries.

Assessment of the long-term hydrologic impacts of Lake Nasser and related irrigation projects in southwestern Egypt.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, J.; Sultan, M.; Environmental Research

2002-05-10

A two-dimensional groundwater flow model was constructed to investigate the long-term hydrologic impacts of Lake Nasser and the major land reclamation projects that use excess lake water in southwest Egypt. Egypt constructed (1964-1971) the Aswan High Dam, creating the Lake Nasser reservoir (length: 500 km; average width: 12 km) and is constructing the Tushka Canal to channel 5.0x10{sup 9} m{sup 3}/yr of Lake Nasser water to reclaim 0.5x10{sup 6} acres of desert lands. The model, constrained by regional-scale groundwater flow and near-lake head data, was successfully calibrated to temporal-observation heads from 1970 to 2000 that reflect variations in lake levels.more » Predictive analyses for the subsequent 50-yr period were conducted by employing the calibrated model. Simulations of long-term effects, beyond year 2000, of Lake Nasser on recharge and temporal groundwater head (base case scenario) show that recharge from the lake will continue at a much slower rate than during the 30-yr period of 1970-2000 (with approximately 86% reduction in 30-yr recharge). The modest projected pumping and injection activities in the study area are not expected to cause major deviation in the overall head distribution compared to the base case scenario. The investigation of effects of the new irrigation land development on the Nubian aquifer indicated that many of the proposed irrigation areas, especially those with small aquifer thickness, will become fully saturated with introduced water, resulting in potential flooding and salinization.« less

Endolithic microbial life in hot and cold deserts

NASA Technical Reports Server (NTRS)

Friedmann, E. I.

1980-01-01

Endolithic microorganisms (those living inside rocks) occur in hot and cold deserts and exist under extreme environmental conditions. These conditions are discussed on a comparative basis. Quantitative estimates of biomass are comparable in hot and cold deserts. Despite the obvious differences between the hot and cold desert environment, survival strategies show some common features. These endolithic organisms are able to 'switch' rapidly their metabolic activities on and off in response to changes in the environment. Conditions in hot deserts impose a more severe environmental stress on the organisms than in the cold Antarctic desert. This is reflected in the composition of the microbial flora which in hot desert rocks consist entirely of prokaryotic microorganisms, while under cold desert conditions eukaryotes predominate.

Effects of off-road vehicles on vertebrates in the California desert

USGS Publications Warehouse

Bury, R. Bruce; Luckenbach, Roger A.; Busack, Stephen D.

1977-01-01

Off-road vehicle (ORV) use provides a form of outdoor recreation that is increasingly popular. The purpose of this study was to examine the impact of these machines on creosote shrub habitat and associated wildlife in the western California Desert. Comparisons at eight paired sites (Control and ORV use) demonstrate that ORV-use areas have significantly fewer species of vertebrates, greatly reduced abundance of individuals, and noticeably lower reptile and small mammal biomass. Diversity, density, and biomass of reptiles and small mammals are inversely related to the level of ORV usage. The number of individuals found in heavily used and pit areas was 55% and 20%, respectively, of that present in undisturbed sites. Biomass estimates were even lower (23% and 17%, respectively). Censuses at three localities also showed decreased diversity, density, and biomass estimates of breeding birds in DRV-used areas. Present evidence indicates that off-road vehicles have a negative effect on desert wildlife over large areas. This widespread impact must be recognized to manage and conserve resources in DRV-use areas.

Ploidy race distributions since the Last Glacial Maximum in the North American desert shrub, Larrea tridentata

USGS Publications Warehouse

Hunter, K.L.; Betancourt, J.L.; Riddle, B.R.; Van Devender, T. R.; Cole, K.L.; Geoffrey, Spaulding W.

2000-01-01

1 A classic biogeographic pattern is the alignment of diploid, tetraploid and hexaploid races of creosote bush (Larrea tridentata) across the Chihuahuan, Sonoran and Mohave Deserts of western North America. We used statistically robust differences in guard cell size of modern plants and fossil leaves from packrat middens to map current and past distributions of these ploidy races since the Last Glacial Maximum (LGM). 2 Glacial/early Holocene (26-10 14C kyr BP or thousands of radiocarbon years before present) populations included diploids along the lower Rio Grande of west Texas, 650 km removed from sympatric diploids and tetraploids in the lower Colorado River Basin of south-eastern California/south-western Arizona. Diploids migrated slowly from lower Rio Grande refugia with expansion into the northern Chihuahuan Desert sites forestalled until after ???4.0 14C kyr BP. Tetraploids expanded from the lower Colorado River Basin into the northern limits of the Sonoran Desert in central Arizona by 6.4 14C kyr BP. Hexaploids appeared by 8.5 14C kyr BP in the lower Colorado River Basin, reaching their northernmost limits (???37??N) in the Mohave Desert between 5.6 and 3.9 14C kyr BP. 3 Modern diploid isolates may have resulted from both vicariant and dispersal events. In central Baja California and the lower Colorado River Basin, modern diploids probably originated from relict populations near glacial refugia. Founder events in the middle and late Holocene established diploid outposts on isolated limestone outcrops in areas of central and southern Arizona dominated by tetraploid populations. 4 Geographic alignment of the three ploidy races along the modern gradient of increasingly drier and hotter summers is clearly a postglacial phenomenon, but evolution of both higher ploidy races must have happened before the Holocene. The exact timing and mechanism of polyploidy evolution in creosote bush remains a matter of conjecture. ?? 2001 Blackwell Science Ltd.

Ploidy race distributions since the Last Glacial Maximum in the North American desert shrub, Larea tridentata

USGS Publications Warehouse

Hunter, Kimberly L.; Betancourt, Julio L.; Riddle, Brett R.; Van Devender, Thomas R.; Cole, K.L.; Spaulding, W.G.

2001-01-01

1. A classic biogeographic pattern is the alignment of diploid, tetraploid and hexaploid races of creosote bush (Larrea tridentata) across the Chihuahuan, Sonoran and Mohave Deserts of western North America. We used statistically robust differences in guard cell size of modern plants and fossil leaves from packrat middens to map current and past distributions of these ploidy races since the Last Glacial Maximum (LGM). 2 Glacial/early Holocene (26a??10 14C kyr bp or thousands of radiocarbon years before present) populations included diploids along the lower Rio Grande of west Texas, 650 km removed from sympatric diploids and tetraploids in the lower Colorado River Basin of south-eastern California/south-western Arizona. Diploids migrated slowly from lower Rio Grande refugia with expansion into the northern Chihuahuan Desert sites forestalled until after ~4.0 14C kyr bp. Tetraploids expanded from the lower Colorado River Basin into the northern limits of the Sonoran Desert in central Arizona by 6.4 14C kyr bp. Hexaploids appeared by 8.5 14C kyr bp in the lower Colorado River Basin, reaching their northernmost limits (~37A?N) in the Mohave Desert between 5.6 and 3.9 14C kyr bp. 3 Modern diploid isolates may have resulted from both vicariant and dispersal events. In central Baja California and the lower Colorado River Basin, modern diploids probably originated from relict populations near glacial refugia. Founder events in the middle and late Holocene established diploid outposts on isolated limestone outcrops in areas of central and southern Arizona dominated by tetraploid populations. 4 Geographic alignment of the three ploidy races along the modern gradient of increasingly drier and hotter summers is clearly a postglacial phenomenon, but evolution of both higher ploidy races must have happened before the Holocene. The exact timing and mechanism of polyploidy evolution in creosote bush remains a matter of conjecture.

Path Dependence and Universal Health Coverage: The Case of Egypt

PubMed Central

Fouda, Ayman; Paolucci, Francesco

2017-01-01

Universal health coverage (UHC) is the big objective in health policy which several countries are seeking to achieve. Egypt is no different and its endeavors to attain UHC have been going on since the 1960s. This article discusses the status of UHC in Egypt using theories of political science and economics by analyzing the historical transformations in the Egyptian health system and its institutional settings. This article then specifically examines the path dependence theory against the sociopolitical background of Egypt and assesses any pattern between the theory and the current UHC status in Egypt. The important finding of this analysis is that the health policies and reforms in Egypt have been significantly influenced and limited by its historical institutional structure and development. Both the health policies and the institutional settings adopted a dependent path that limited Egypt’s endeavors to achieve the universal coverage. This dependent path also yielded many of the present-day challenges as in the weaknesses of the healthcare financing system and the inability to extend health coverage to the poor and the informal sector. These challenges subsequently had a negative impact on the accessibility of the healthcare services. PMID:29276704

Amplified Fragment Length Polymorphism Diversity in Cephalosporium maydis from Egypt.

PubMed

Saleh, Amgad A; Zeller, Kurt A; Ismael, Abou-Serie M; Fahmy, Zeinab M; El-Assiuty, Elhamy M; Leslie, John F

2003-07-01

ABSTRACT Cephalosporium maydis, the causal agent of late wilt of maize, was first described in Egypt in the 1960s, where it can cause yield losses of up to 40% in susceptible plantings. We characterized 866 isolates of C. maydis collected from 14 governates in Egypt, 7 in the Nile River Delta and 7 in southern (Middle and Upper) Egypt, with amplified fragment length polymorphism (AFLP) markers. The four AFLP primer-pair combinations generated 68 bands, 25 of which were polymorphic, resulting in 52 clonal haplotypes that clustered the 866 isolates into four phylogenetic lineages. Three lineages were found in both the Nile River Delta and southern Egypt. Lineage IV, the most diverse group (20 haplotypes), was recovered only from governates in the Nile River Delta. In some locations, one lineage dominated (up to 98% of the isolates recovered) and, from some fields, only a single haplotype was recovered. Under field conditions in Egypt, there is no evidence that C. maydis reproduces sexually. The nonuniform geographic distribution of the pathogen lineages within the country could be due to differences in climate or in the farming system, because host material differs in susceptibility and C. maydis lineages differ in pathogenicity.

Biomphalaria alexandrina in Egypt: past, present and future.

PubMed

Abou-El-Naga, Iman F

2013-09-01

The African species of Biomphalaria appeared as a result of the relatively recent west-to-east trans-Atlantic dispersal of the Biomphalaria glabrata-like taxon. In Egypt, Biomphalaria alexandrina is the intermediate host for Schistosoma mansoni. Biomphalaria alexandrina originated in the area between Alexandria and Rosetta and has historically been confined to the Nile Delta. Schistosoma mansoni reached Egypt via infected slaves and baboons from the Land of Punt through migrations that occurred as early as the Vth Dynasty. The suggestion of the presence of Schistosoma mansoni infection in Lower Egypt during Pharaonic times is discussed despite the fact that that there is no evidence of such infection in Egyptian mummies. It is only recently that Biomphalaria alexandrina colonized the Egyptian Nile from the Delta to Lake Nasser. This change was likely due to the construction of huge water projects, the development of new water resources essential for land reclamation projects and the movement of refugees from the Suez Canal zone to the Delta and vice versa. The situation with respect to Biomphalaria in Egypt has become complicated in recent years by the detection of Biomphalaria glabrata and a hybrid between both species; however, follow-up studies have demonstrated the disappearance of such species within Egypt. The National Schistosoma Control Program has made great strides with respect to the eradication of schistosoma; however, there has unfortunately been a reemergence of Schistosoma mansoni resistant to praziquantel. There are numerous factors that may influence the prevalence of snails in Egypt, including the construction of water projects, the increase in reclaimed areas, global climate change and pollution. Thus, continued field studies in addition to the cooperation of several scientists are needed to obtain an accurate representation of the status of this species. In addition, the determination of the genome sequence for Biomphalaria alexandrina and the

HIGH FOLIAR NITROGEN IN DESERT SHRUBS: AN IMPORTANT ECOSYSTEM TRAIT OR DEFECTIVE DESERT DOCTRINE?

EPA Science Inventory

Nitrogen concentrations in green and senesced leaves of perennial desert shrubs were compiled from a worldwide literature search to test the validity of the doctrine that desert shrubs produce foliage and leaf litter much richer in nitrogen than that in the foliage of plants from...

Establishing the first institutional animal care and use committee in Egypt.

PubMed

Fahmy, Sohair R; Gaafar, Khadiga

2016-04-09

Although animal research ethics committees (AREC) are well established in Western countries, this field is weakly developed and its concept is poorly understood in the Middle East and North Africa region. Our main objective was to introduce the concept and requirements of ethical approaches in dealing with experimental animal in research and teaching in Egypt. Due to its very recent inception, Cairo University, Faculty of Science IACUC decided to operate in accordance with Guide for the Care and Use of Laboratory Animals 8th Edition 2011 (the Guide) since Egypt has not yet compiled its own guide. Fifty protocols were reviewed in 2013-2014. Only ten protocols were reviewed in 2013, but in 2014, forty protocols were reviewed. In 2013 all protocols were approved and in 2014, number of approvals were 35, the number of deferrals were 4, and one refused protocol. Master's theses (MSc) research protocols constituted the majority of the total reviewed protocols. This is attributed to the decision of the Board of the Faculty of Science, Cairo University in September, 2013 that the approval of the IACUC is mandatory before conducting any research involving animals or theses registration. The first IACUC was established in the Cairo University, Faculty of Science, since 2012. The challenges encountered by the committee were diverse, such as the absence of laws that control the use of animal models in scientific research, lack of guidelines (protocols for experimental animals in research) and, mandatory ethical approval for any experimental animal research.

Desert tortoise use of burned habitat in the Eastern Mojave desert

USGS Publications Warehouse

Drake, Karla K.; Esque, Todd C.; Nussear, Kenneth E.; DeFalco, Lesley; Scoles, Sara; Modlin, Andrew T.; Medica, Philip A.

2015-01-01

Wildfires burned 24,254 ha of critical habitat designated for the recovery of the threatened Mojave desert tortoise (Gopherus agassizii) in southern Nevada during 2005. The proliferation of non-native annual grasses has increased wildfire frequency and extent in recent decades and continues to accelerate the conversion of tortoise habitat across the Mojave Desert. Immediate changes to vegetation are expected to reduce quality of critical habitat, yet whether tortoises will use burned and recovering habitat differently from intact unburned habitat is unknown. We compared movement patterns, home-range size, behavior, microhabitat use, reproduction, and survival for adult desert tortoises located in, and adjacent to, burned habitat to understand how tortoises respond to recovering burned habitat. Approximately 45% of home ranges in the post-fire environment contained burned habitat, and numerous observations (n = 12,223) corroborated tortoise use of both habitat types (52% unburned, 48% burned). Tortoises moved progressively deeper into burned habitat during the first 5 years following the fire, frequently foraging in burned habitats that had abundant annual plants, and returning to adjacent unburned habitat for cover provided by intact perennial vegetation. However, by years 6 and 7, the live cover of the short-lived herbaceous perennial desert globemallow (Sphaeralcea ambigua) that typically re-colonizes burned areas declined, resulting in a contraction of tortoise movements from the burned areas. Health and egg production were similar between burned and unburned areas indicating that tortoises were able to acquire necessary resources using both areas. This study documents that adult Mojave desert tortoises continue to use habitat burned once by wildfire. Thus, continued management of this burned habitat may contribute toward the recovery of the species in the face of many sources of habitat loss.

Tectonic architecture through Landsat-7 ETM+/SRTM DEM-derived lineaments and relationship to the hydrogeologic setting in Siwa region, NW Egypt

NASA Astrophysics Data System (ADS)

Masoud, Alaa; Koike, Katsuaki

2006-08-01

Fracture zones on the Earth's surface are important elements in the understanding of plate motion forces, the dynamics of the subsurface fluid flow, and earthquake distributions. However, good exposures of these features are always lacking in arid regions, characterized by flat topography and where sand dunes extensively cover the terrain. During field surveys these conditions, in many cases, hinder the proper characterization of such features. Therefore, an approach that identifies the regional fractures as lineaments on remotely-sensed images or shaded digital terrain models, with its large scale synoptic coverage, could be promising. In the present work, a segment tracing algorithm (STA), for lineament detection from Landsat-7 Enhanced Thematic Mapper Plus (ETM+) imagery, and the data from the Shuttle Radar Topographic Mission (SRTM) 30 m digital elevation model (DEM), has been applied in the Siwa region, located in the northwest of the Western Desert of Egypt. The objectives are to analyze the spatial variation in orientation of the detected linear features and its relation to the hydrogeologic setting in the area and the underlying geology, and to evaluate the performance of the algorithm applied to the ETM+ and the DEM data. Detailed structural analysis and better understanding of the tectonic evolution of the area could provide useful tools for hydrologists for reliable groundwater management and development planning. The results obtained have been evaluated by the structural analysis of the area and field observations. Four major vertical fracture zones were detected corresponding to two conjugate sets of strike-slip faults that governed the surface, and subsurface environments of the lakes in the region, and these correlate well with the regional tectonics.

Multiscale Local Forcing of the Arabian Desert Daytime Boundary Layer, and Implications for the Dispersion of Surface-Released Contaminants.

NASA Astrophysics Data System (ADS)

Warner, Thomas T.; Sheu, Rong-Shyang

2000-05-01

Four 6-day simulations of the atmospheric conditions over the Arabian Desert during the time of the 1991 detonation and release of toxic material at the Khamisiyah, Iraq, weapons depot were performed using a mesoscale model run in a data-assimilation mode. These atmospheric simulations are being employed in a forensic analysis of the potential contribution of the toxic material to so-called Gulf War illness. The transport and concentration of such surface-released contaminants are related strongly to the planetary boundary layer (PBL) depth and the horizontal wind speed in the PBL. The product of the PBL depth and the mean wind speed within it is referred to as the ventilation and is used as a metric of the horizontal transport within the PBL. Thus, a corollary study to the larger forensic analysis involves employing the model solutions and available data in an analysis of the multiscale spatial variability of the daytime desert PBL depth and ventilation as they are affected by surface forcing from terrain elevation variations, coastal circulations, and contrasts in surface physical properties.The coarsest computational grid spanned the entire northern Arabian Desert and surrounding areas of the Middle East, and represented the large-scale PBL modulation by the orography. The PBL depths were greatest over the high elevations of the western Arabian Peninsula and over the Zagros Mountains in western Iran and were shallowest over water bodies and the lower elevations in the Tigris-Euphrates Valley. Higher-resolution grids in the nest (the smallest grid increment was 3.3 km) showed that the PBL depth minimum in the Tigris-Euphrates Valley was likely a consequence of compensating subsidence associated with the thermally forced daytime upward motion over the Zagros Mountains to the east in Iran, with possible contributions from an elevated mixed layer. Further local modulation of the daytime desert PBL occurred as a result of the inland penetration of the coastal sea

Little Ice Age Wetting of Interior Asian Deserts and the Rise of the Mongol Empire

NASA Astrophysics Data System (ADS)

Putnam, A. E.; Putnam, D.; Andreu-Hayles, L.; Cook, E. R.; Palmer, J. G.; Clark, E. H.; WANG, C.; Chen, F.; Denton, G.; Boyle, D. P.; Bassett, S.; Birkel, S. D.; Martin Fernandez, J.; Hajdas, I.; Southon, J. R.; Garner, C.; Broecker, W. S.

2015-12-01

Documenting hydrological responses to past climate changes may provide insights into how ongoing warming will alter the distribution of Earth's water resources. Here we report evidence suggesting that wetter-than-present conditions persisted during the past millennium in the deserts of the Tarim Basin, western China, located at the heart of Asia - Earth's largest and most populous continent. Our assessment is based on observations of landforms composed of waterlain sediments occurring throughout the Taklamakan and Lop Deserts of the Tarim Basin. These landforms are associated with subfossil phreatophyte trees, reeds, and mollusk shells. We applied 14C and dendrochronological dating techniques to construct a chronology for when the Tarim Basin was wetter than today. We also employed hydrological modeling to estimate plausible climatic conditions under which the observed wet environment could have been sustained. Our results indicate that the core of the Asian desert belt was dominantly wetter than today during the last major cold spell of the Holocene: The Little Ice Age. Wetter conditions in the Tarim Basin deserts accompanied northern cooling, snowline lowering, a strengthened boreal jet, and coeval weakening of south Asian monsoons. Southward migration of grasslands in response to wetter conditions may have aided the spread of the Mongol Empire across Asian drylands. On the other hand, net drying over the 20th century has led to drought that is unprecedented for at least the past ~830 years, and which could intensify with further warming.

Desert Tortoise (Gopherus agassizii)

USGS Publications Warehouse

Boarman, William I.; Boarman, William I.; Beaman, K.

2002-01-01

The desert tortoise is widely distributed throughout major portions of the Mojave and Sonoran deserts of California, Nevada, Utah, Arizona, Sonora, and Sinaloa. Genetic, morphological, ecological, and behavioral features suggest an evolutionary divergence between the tortoises found south and east of the Colorado River (“Sonoran population”), and those found north and west of the river (“Mojave population;” Lamb et al. 1989). The latter is the population Federally and State-listed as threatened. This population will be referred to in the remainder of this account. The majority of animals in the Mojave population occur at variable densities in six distinct population segments (i.e., evolutionarily significant units), each identified in the Recovery Plan for desert tortoises as separate Recovery Units (USFWS 1994).

Adolescent tramadol use and abuse in Egypt.

PubMed

Bassiony, Medhat M; Salah El-Deen, Ghada M; Yousef, Usama; Raya, Yasser; Abdel-Ghani, Mohamed M; El-Gohari, Hayam; Atwa, Samar A

2015-05-01

Tramadol abuse liability is underestimated and the evidence of abuse and dependence is emerging. It has many health and social consequences especially in adolescents. Tramadol abuse has not been well studied in Egypt. The aim of this study was to estimate the prevalence and associated correlates of tramadol use and abuse among school students in Egypt. A total of 204 students, aged 13-18 years, from six schools in Zagazig, Egypt, were screened for tramadol use using The Drug Use Disorders Identification Test and a urine screen for tramadol. The prevalence of tramadol use was 8.8% among school students and the average age at onset of tramadol use was 16.5 ± 1.1. Some 83% of the users were using tramadol alone while the rest (17%) were using a combination of tramadol, alcohol, and cannabis. Two-thirds of these students started with tramadol as the first drug after the onset of tobacco smoking. Over one third of tramadol users had drug-related problems and 6% had dependence. There was a significant association between tramadol use and older age, male gender, and smoking. Drug-related problems were negatively correlated with age at onset of tramadol use. Tramadol use was common among adolescents and over one third of tramadol users had drug-related problems. Population-based longitudinal studies are needed to investigate tramadol use and the possible role of tramadol as a gateway drug in the development of substance abuse in Egypt.

Taghrid Samak Works to Affect Social Development in Egypt

Science.gov Websites

; Technology Archive Home » News & Publications » News » CRD's Taghrid Samak Works to Affect Social Affect Social Development in Egypt March 29, 2013 Jon Bashor, Jbashor@lbl.gov, +1 510 486 5849 advancing social development in Egypt. Since the Egyptian uprising that ultimately toppled the 30-year reign

Solar energy distribution over Egypt using cloudiness from Meteosat photos

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mosalam Shaltout, M.A.; Hassen, A.H.

1990-01-01

In Egypt, there are 10 ground stations for measuring the global solar radiation, and five stations for measuring the diffuse solar radiation. Every day at noon, the Meteorological Authority in Cairo receives three photographs of cloudiness over Egypt from the Meteosat satellite, one in the visible, and two in the infra-red bands (10.5-12.5 {mu}m) and (5.7-7.1 {mu}m). The monthly average cloudiness for 24 sites over Egypt are measured and calculated from Meteosat observations during the period 1985-1986. Correlation analysis between the cloudiness observed by Meteosat and global solar radiation measured from the ground stations is carried out. It is foundmore » that, the correlation coefficients are about 0.90 for the simple linear regression, and increase for the second and third degree regressions. Also, the correlation coefficients for the cloudiness with the diffuse solar radiation are about 0.80 for the simple linear regression, and increase for the second and third degree regression. Models and empirical relations for estimating the global and diffuse solar radiation from Meteosat cloudiness data over Egypt are deduced and tested. Seasonal maps for the global and diffuse radiation over Egypt are carried out.« less

An ancient scourge: the end of dracunculiasis in Egypt.

PubMed

Watts, S

1998-04-01

This paper addresses the question of when guinea worm disease was last found in Egypt, and how written sources from the nineteenth and twentieth centuries which mention the disease should be evaluated. This enquiry is relevant to the global eradication campaign now in progress, and the need for countries in which dracunculiasis was once present to prepare a certification of eradication. Sudan, the country which has the largest number of cases today, is Egypt's southern neighbour. Because of the nature of the disease (in endemic areas it is most common among poor, rural people), it may not have come to the attention of urban-based health personnel. In the period before the details of the transmission cycle were known, the attitudes and mindsets of physicians and travellers also have to be taken into account in interpreting written reports of the disease. An examination of documentary sources from the nineteenth and twentieth centuries in European languages does not show any clear evidence for dracunculiasis transmission in Egypt during that period. Cases noted in Egypt, especially by the much quoted Dr Clot Bey in the 1820s, most likely originated beyond the borders of the country, in Sudan and, to a lesser extent, from endemic areas in the Middle East. However, many later commentators merely repeated what Clot Bey had written. A further difficulty is that some published reports which apparently concern dracunculiasis in Egypt, actually refer to cases in animals rather than humans.

The Impact of Biogenic and Anthropogenic Atmospheric Aerosol on Climate in Egypt

NASA Astrophysics Data System (ADS)

Ibrahim, A. I.; Zakey, A.; Steiner, A. L.; Shokr, M. E.; El-Raey, M.; Ahmed, Y.; Al-Hadidi, A.; Zakey, A.

2014-12-01

Aerosols are indicators of air quality as they reduce visibility and adversely affect public health. Aerosol optical depth (AOD) is a measure of the radiation extinction due to interaction of radiation with aerosol particles in the atmosphere. Using this optical measure of atmospheric aerosols we explore the seasonal and annual patterns of aerosols from both anthropogenic and biogenic sources over Egypt. Here, we use an integrated environment-climate-aerosol model in conjunction with inversion technique to identify the aerosol particle size distribution over different locations in Egypt. The online-integrated Environment-Climate-Aerosol model (EnvClimA), which is based on the International Center for Theoretical Physics Regional Climate Model (ICTP-RegCM), is used to study the emission of different aerosols and their impact on climate parameters for a long-term base line simulation run over Egypt and North Africa. The global emission inventory is downscaled and remapping them over Egypt using local factors such as population, traffic and industrial activities to identify the sources of anthropogenic and biogenic emission from local emission over Egypt. The results indicated that the dominant natural aerosols over Egypt are dust emissions that frequently occur during the transitional seasons (Spring and Autumn). From the local observation we identify the number of dust and sand storm occurrences over Egypt. The Multiangle Imaging SpectroRadiometer (MISR) is used to identify the optical characterizations of different types of aerosols over Egypt. Modeled aerosol optical depth and MISR observed (at 555 nm) are compared from March 2000 through November 2013. The results identify that the MISR AOD captures the maximum peaks of AOD in March/April that coincide with the Khamasin dust storms. However, peaks in May are either due to photochemical reactions or anthropogenic activities. Note: This presentation is for a Partnerships for Enhanced Engagement in Research (PEER

Assessing groundwater recharge mechanisms in the Pampa del Tamarugal Basin of northern Chile's Atacama Desert

NASA Astrophysics Data System (ADS)

Jayne, R., Jr.; Pollyea, R.; Dodd, J. P.; Olson, E. J.; Swanson, S.

2015-12-01

The hyper-arid Atacama Desert in northern Chile is one of the driest inhabited places on Earth receiving little to no rain (<5 mm/yr). Within the Tarapacá Region of the Atacama Desert, the Pampa del Tamarugal Aquifer (PTA) is the primary source of water for agriculture, industry, mining, and residential uses. The PTA covers 5,000 km2, and is located in the Pampa del Tamarugal Basin, which is situated between the Andes and the Coastal Cordillera, and is filled with ~1700m of Miocene and younger sediments. The source of recharge for the PTA originates as precipitation in the high Andes, which can receive up to 400 mm/yr of precipitation; however, the mechanisms and magnitude of recharge to the PTA are still poorly understood. Here, we present a regional scale, non-isothermal 2-D numerical groundwater model is developed to analyze the time scales and geological controls on fluid flow paths recharging the PTA. Results from this work suggest that (1) both shallow groundwater flow and deep (>1km) hydrothermal fluid circulation are responsible for recharging the PTA; (2) topography and geothermal gradients are the main driving factors for regional groundwater flow; (3) the Altos de Pica member 4, an ignimbrite layer in the sedimentary basin controls both heat and fluid flow in the western part of the basin, this is evident due to the presence of convection cells and meteoric water upwelling and presenting itself as surface water (salars); and (4) it takes meteoric water 100,000 years to travel from the high Andes to reach Pica and 1,000,000 years for salar formation. In addition, this work provides a theoretical basis for the spatial distribution of highly alkaline surface water bodies, known as salars in the western Atacama Desert.

Changes in urine parameters after desert exposure: assessment of stone risk in United States Marines transiently exposed to a desert environment.

PubMed

Masterson, James H; Jourdain, Victor J; Collard, Daniel A; Choe, Chong H; Christman, Matthew S; L'Esperance, James O; Auge, Brian K

2013-01-01

Living in a desert environment has been associated with a higher incidence of kidney stone formation, likely because of concentrated urine output, higher production of vitamin D and genetic predisposition. We determined the changes in urinary parameters after a group of United States Marines temporarily transitioned from a temperate environment to a desert environment. A total of 50 Marines completed a questionnaire and performed 3, 24-hour urine collections before mobilization to the desert, after 30 days in the desert and 2 weeks after returning from the desert. Daily urine output decreased 68% to 0.52 L despite marked increased fluid intake (17 L per day). Total daily urinary excretion of calcium, uric acid, sodium, magnesium and potassium in the desert decreased by 70%, 41%, 53%, 22% and 36%, respectively. Urinary pH decreased from 6.1 to 5.6 while in the desert, and citrate and oxalate had minimal changes. After their return from the desert, apart from a decrease of 22% in oxalate, there were no statistically significant differences from baseline. While in the desert, relative supersaturation risks of uric acid and sodium urate were increased 153% and 56%, respectively. Brushite relative supersaturation decreased 24%. After their return there was no statistical difference from baseline. Our findings suggest that the kidneys preserved water and electrolytes while the Marines were subjected to the desert environment. Despite this conservation, relative saturations indicate increased risk of stones in healthy men exposed to a desert environment with rapid resolution upon return. Copyright © 2013 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Occurrence of hexavalent chromium in ground water in the western Mojave Desert, California

USGS Publications Warehouse

Ball, J.W.; Izbicki, J.A.

2004-01-01

About 200 samples from selected public supply, domestic, and observation wells completed in alluvial aquifers underlying the western Mojave Desert were analyzed for total dissolved Cr and Cr(VI). Because Cr(VI) is difficult to preserve, samples were analyzed by 3 methods. Chromium(VI) was determined in the field using both a direct colorimetric method and EPA method 218.6, and samples were speciated in the field for later analysis in the laboratory using a cation-exchange method developed for the study described in this paper. Comparison of the direct colorimetric method and EPA method 218.6 with the new cation-exchange method yielded r2 values of 0.9991 and 0.9992, respectively. Total dissolved Cr concentrations ranged from less than the 0.1 ??g/l detection limit to 60 ??g/l, and almost all the Cr present was Cr(VI). Near recharge areas along the mountain front pH values were near neutral, dissolved O2 concentrations were near saturation, and Cr(VI) concentrations were less than the 0.1 ??g/l detection limit. Chromium(VI) concentrations and pH values increased downgradient as long as dissolved O 2 was present. However, low Cr(VI) concentrations were associated with low dissolved O2 concentrations near ground-water discharge areas along dry lakes. Chromium(VI) concentrations as high as 60 ??g/l occurred in ground water from the Sheep Creek fan alluvial deposits weathered from mafic rock derived from the San Gabriel Mountains, and Cr(VI) concentrations as high as about 36 ??g/l were present in ground water from alluvial deposits weathered from less mafic granitic, metamorphic, and volcanic rocks. Chromium(III) was the predominant form of Cr only in areas where dissolved O2 concentrations were less than 1 mg/l and was detected at a median concentration of 0.1 ??g/l, owing to its low solubility in water of near-neutral pH. Depending on local hydrogeologic conditions and the distribution of dissolved O2, Cr(VI) concentrations may vary considerably with depth. Samples

Simulated climate effects of desert irrigation geoengineering.

PubMed

Cheng, Wei; Moore, John C; Cao, Long; Ji, Duoying; Zhao, Liyun

2017-04-18

Geoengineering, the deliberate large-scale manipulation of earth's energy balance to counteract global warming, is an attractive proposition for sparsely populated deserts. We use the BNU and UVic Earth system models to simulate the effects of irrigating deserts under the RCP8.5 scenario. Previous studies focused on increasing desert albedo to reduce global warming; in contrast we examine how extending afforestation and ecological projects, that successfully improve regional environments, fair for geoengineering purposes. As expected desert irrigation allows vegetation to grow, with bare soil or grass gradually becoming shrub or tree covered, with increases in terrestrial carbon storage of 90.3 Pg C (UVic-ESCM) - 143.9 Pg C (BNU-ESM). Irrigating global deserts makes the land surface temperature decrease by 0.48 °C and land precipitation increase by 100 mm yr -1 . In the irrigated areas, BNU-ESM simulates significant cooling of up to 4.2 °C owing to the increases in low cloud and latent heat which counteract the warming effect due to decreased surface albedo. Large volumes of water would be required to maintain global desert irrigation, equivalent 10 mm/year of global sea level (BNU-ESM) compensate for evapotranspiration losses. Differences in climate responses between the deserts prompt research into tailored albedo-irrigation schemes.

Fulbright-Hays Summer Seminars Abroad Program 1989. Egypt: Transition to the Modern World.

ERIC Educational Resources Information Center

Office of International Education (ED), Washington, DC.

This document consists of four papers on various aspects of development in Egypt prepared by participants in the Fulbright-Hays Seminars Abroad Program in Egypt in 1989. Four of the papers are descriptive, one is a lesson plan. The papers included are: (1) "Egypt: Transition to Modern Times" (Katherine Jensen) focuses on the role of…

Clinical Management of Gender in Egypt: Intersexuality and Transsexualism.

PubMed

Mazen, Inas A

2017-02-01

This article reviews the literature on intersexuality (disorders of sex development [DSD]) and transsexuality in Egypt. Egypt's resources for the diagnosis and treatment of rare conditions, such as DSD and transsexualism, are quite limited. The birth of a child with a DSD is likely to be stressful, especially in regard to decisions on gender assignment, and genital abnormalities are associated with stigma and shame. Gender assignment may be biased toward the male gender, because female infertility precludes marriage and female gender adversely affects employment prospects and inheritance. Later gender change in either direction may also carry stigma. Gender reassignment surgery for transsexuals without somatic intersexuality was legalized in Egypt in 2005, but requires permission by a national Sex Identification and Determination Committee.

Lyme borreliosis: A neglected zoonosis in Egypt.

PubMed

Elhelw, Rehab A; El-Enbaawy, Mona I; Samir, Ahmed

2014-12-01

Borrelia burgdorferi, the causal organism of Lyme borreliosis. In Egypt, available data about the occurrence of Lyme disease are scarce and no structured studies documented the presence of Lyme borreliosis in Egyptian animals and tick reservoirs verifying its zoonotic evidence. Besides, no successful trials to isolate B. burgdorferi from clinical samples have occurred. This study was conducted to investigate B. burgdorferi infection as an emerging zoonosis neglected in Egypt. A total number of 92 animals, tick and human companion specimens were collected and subjected for culture, PCR and/or serodetection. B. burgdorferi has been detected and isolated from Egyptian animal breeds. We also detected the presence of outer surface protein A gene of B. burgdorferi by PCR as well as anti-B. burgdorferi IgM by ELISA in human contacts who were suffering from fever of unknown origin. This report represents the first systematic study on animals associated with patients suffering from febrile illness to confirm the emerging of such neglected zoonosis in Egypt. Copyright © 2014 Elsevier B.V. All rights reserved.

Publications of the Western Earth Surface Processes Team 2006

USGS Publications Warehouse

Powell, Charles L.; Stone, Paul

2007-01-01

The Western Earth Surface Processes Team (WESPT) of the U.S. Geological Survey (USGS) conducts geologic mapping, earth-surface process investigations, and related topical earth science studies in the western United States. This work is focused on areas where modern geologic maps and associated earth-science data are needed to address key societal and environmental issues such as ground-water quality, landslides and other potential geologic hazards, and land-use decisions. Areas of primary emphasis in 2006 included southern California, the San Francisco Bay region, the Mojave Desert, the Colorado Plateau region of northern Arizona, and the Pacific Northwest. The team has its headquarters in Menlo Park, California, and maintains smaller field offices at several other locations in the western United States. This compilation gives the bibliographical citations for 123 new publications, most of which are available online using the hyperlinks provided.

Ancient Egypt: Personal Perspectives.

ERIC Educational Resources Information Center

Wolinski, Arelene

This teacher resource book provides information on ancient Egypt via short essays, photographs, maps, charts, and drawings. Egyptian social and religious life, including writing, art, architecture, and even the practice of mummification, is conveniently summarized for the teacher or other practitioner in a series of one to three page articles with…

Egypt`s first remotely controlled subsea completion -- A Gulf of Suez case history

DOE Office of Scientific and Technical Information (OSTI.GOV)

El Hawary, A.; Hoffman, J.G.

1995-11-01

A case history of the Gulf of Suez Petroleum Company`s (GUPCO) first remotely controlled subsea completion is provided. The first completion was for well GS 373-2, a previously drilled and tested exploration well located in the south portion of the Gulf of Suez. Subsea technology was utilized to economically justify development of this one well marginal field which was discovered in 1978. Traditional methods proved to be too costly for development, therefore application of a low cost subsea tree was utilized to capture the resources. In the Gulf of Suez many fields have been discovered by have not been developedmore » due to low reserves. These marginal projects can have a profound impact on the revenue and shareholder value if any economic method is used to exploit these opportunities. Platform installation was not feasible due to reserve size, hence the well has remained abandoned until recently. Capturing the experience of Amoco in the Gulf of Mexico and in the Dutch North Sea, GUPCO was able to build a low cost subsea system which would allow for the economic development of the marginal fields discovered in the past. This paper presents a summarized look at subsea completion technology. The cost comparison of traditional development methods will be made, given the local cost structure in Egypt. The application of this technology has some limitations and constraints which will be discussed in the paper. Furthermore the actual field installation of Egypt`s first remotely controlled subsea tree will be summarized. Also included is a discussion on simple remote controls,and offshore installation operations.« less

Ethnomycological survey of traditional usage and indigenous knowledge on desert truffles among the native Sahara Desert people of Algeria.

PubMed

Bradai, Lyès; Neffar, Souad; Amrani, Khaled; Bissati, Samia; Chenchouni, Haroun

2015-03-13

Desert truffles are edible hypogeous fungi, highly appreciated by the inhabitants of hot-desert settlements. Native Saharan people use truffles for food, promoting tourism, increasing fertility, and treatment of eye diseases and fatigue. This study consists of a cross-sectional survey focusing on the knowledge, use and ethnomycological practices of desert truffles among the native people of the Algerian Northern Sahara. The study was conducted through direct interviews with 60 truffle-hunters in the regions of Ouargla and Ghardaia. Three species were harvested and consumed by the surveyed subjects: Terfezia claveryi was the most appreciated and most expensive species, followed by Terfezia areanaria moderately preferred, then Tirmania nivea the least appreciated and least expensive. Among the 60 interviewees, 90% rely on the abundance of symbiotic plants (Helianthemum lippii) to harvest truffles, 65% begin harvesting from mid-February to March, after rains of the autumn (38%) and winter (36%), particularly in the Wadi beds (37%) and Daya landscapes (32%). Interviewees harvested truffles mainly for home consumption; however 26.7% sell any harvest surplus, and of those only 15% generate significant revenue from this source, and 73% considered the sale of desert truffles to have low financial value. Desert truffles are used in traditional medicine, especially against eye infections (22%), weakness (19%) and to promote male fertility (19%). In the case of desert truffles for consumption, the surveyed population preferred to prepare the truffles with couscous and meat, or in porridge. Respondents used price as the main criterion for deciding whether to purchase desert truffles. The surveyed trufflers use the knowledge passed from one generation to the next to help ensure a good harvest of truffles during each foray into the desert. Our findings highlight the various uses of truffles in the Sahara Desert, and how these relate to the lifestyle of local people. Copyright �

National water, food, and trade modeling framework: The case of Egypt.

PubMed

Abdelkader, A; Elshorbagy, A; Tuninetti, M; Laio, F; Ridolfi, L; Fahmy, H; Hoekstra, A Y

2018-10-15

This paper introduces a modeling framework for the analysis of real and virtual water flows at national scale. The framework has two components: (1) a national water model that simulates agricultural, industrial and municipal water uses, and available water and land resources; and (2) an international virtual water trade model that captures national virtual water exports and imports related to trade in crops and animal products. This National Water, Food & Trade (NWFT) modeling framework is applied to Egypt, a water-poor country and the world's largest importer of wheat. Egypt's food and water gaps and the country's food (virtual water) imports are estimated over a baseline period (1986-2013) and projected up to 2050 based on four scenarios. Egypt's food and water gaps are growing rapidly as a result of steep population growth and limited water resources. The NWFT modeling framework shows the nexus of the population dynamics, water uses for different sectors, and their compounding effects on Egypt's food gap and water self-sufficiency. The sensitivity analysis reveals that for solving Egypt's water and food problem non-water-based solutions like educational, health, and awareness programs aimed at lowering population growth will be an essential addition to the traditional water resources development solution. Both the national and the global models project similar trends of Egypt's food gap. The NWFT modeling framework can be easily adapted to other nations and regions. Copyright © 2018. Published by Elsevier B.V.

Orthopedic surgery in ancient Egypt

PubMed Central

Blomstedt, Patric

2014-01-01

Background — Ancient Egypt might be considered the cradle of medicine. The modern literature is, however, sometimes rather too enthusiastic regarding the procedures that are attributed an Egyptian origin. I briefly present and analyze the claims regarding orthopedic surgery in Egypt, what was actually done by the Egyptians, and what may have been incorrectly ascribed to them. Methods — I reviewed the original sources and also the modern literature regarding surgery in ancient Egypt, concentrating especially on orthopedic surgery. Results — As is well known, both literary sources and the archaeological/osteological material bear witness to treatment of various fractures. The Egyptian painting, often claimed to depict the reduction of a dislocated shoulder according to Kocher’s method, is, however, open to interpretation. Therapeutic amputations are never depicted or mentioned in the literary sources, while the specimens suggested to demonstrate such amputations are not convincing. Interpretation — The ancient Egyptians certainly treated fractures of various kinds, and with varying degrees of success. Concerning the reductions of dislocated joints and therapeutic amputations, there is no clear evidence for the existence of such procedures. It would, however, be surprising if dislocations were not treated, even though they have not left traces in the surviving sources. Concerning amputations, the general level of Egyptian surgery makes it unlikely that limb amputations were done, even if they may possibly have been performed under extraordinary circumstances. PMID:25140982

The genus Macroocula Panfilov in Egypt, with two new species (Hymenoptera: Bradynobaenidae: Apterogyninae).

PubMed

Gadallah, Neveen S; Soliman, Ahmed M; Al-Shahat, Ahmed M; Hossni, Mohammed T

2015-09-16

The genus Macroocula Panfilov in Egypt is reviewed. Seven species were previously recorded from Egypt: M. magna (Invrea, 1965), M. mahunkai Argaman, 1994, M. morawitzi (Radoszkowski, 1888), M. nigriventris (Invrea, 1960), M. nitida (Bischoff, 1920), M. savignyi (Klug, 1829) and M. sinaica (Invrea, 1963). Macroocula brothersi Gadallah & Soliman, sp. nov. (Egypt, Wadi Shab, Red Sea) and M. salehi Gadallah & Soliman, sp. nov. (Egypt, Wadi Shaghab, Aswan) are described and illustrated. The subspecies M. nitida nitida (Bischoff, 1920) and M. nitida patrizii (Invrea, 1932) are raised to species level. An illustrated key and a faunistic list of Macroocula species are given.

Desert dust hazards: A global review

NASA Astrophysics Data System (ADS)

Middleton, N. J.

2017-02-01

Dust storms originate in many of the world's drylands and frequently present hazards to human society, both within the drylands themselves but also outside drylands due to long-range transport of aeolian sediments. Major sources of desert dust include the Sahara, the Middle East, central and eastern Asia, and parts of Australia, but dust-raising occurs all across the global drylands and, on occasion, beyond. Dust storms occur throughout the year and they vary in frequency and intensity over a number of timescales. Long-range transport of desert dust typically takes place along seasonal transport paths. Desert dust hazards are here reviewed according to the three phases of the wind erosion system: where dust is entrained, during the transport phase, and on deposition. This paper presents a synthesis of these hazards. It draws on empirical examples in physical geography, medical geology and geomorphology to discuss case studies from all over the world and in various fields. These include accelerated soil erosion in agricultural zones - where dust storms represent a severe form of accelerated soil erosion - the health effects of air pollution caused by desert aerosols via their physical, chemical and biological properties, transport accidents caused by poor visibility during desert dust events, and impacts on electricity generation and distribution. Given the importance of desert dust as a hazard to human societies, it is surprising to note that there have been relatively few attempts to assess their impact in economic terms. Existing studies in this regard are also reviewed, but the wide range of impacts discussed in this paper indicates that desert dust storms deserve more attention in this respect.

Multi scenario seismic hazard assessment for Egypt

NASA Astrophysics Data System (ADS)

Mostafa, Shaimaa Ismail; Abd el-aal, Abd el-aziz Khairy; El-Eraki, Mohamed Ahmed

2018-01-01

Egypt is located in the northeastern corner of Africa within a sensitive seismotectonic location. Earthquakes are concentrated along the active tectonic boundaries of African, Eurasian, and Arabian plates. The study area is characterized by northward increasing sediment thickness leading to more damage to structures in the north due to multiple reflections of seismic waves. Unfortunately, man-made constructions in Egypt were not designed to resist earthquake ground motions. So, it is important to evaluate the seismic hazard to reduce social and economic losses and preserve lives. The probabilistic seismic hazard assessment is used to evaluate the hazard using alternative seismotectonic models within a logic tree framework. Alternate seismotectonic models, magnitude-frequency relations, and various indigenous attenuation relationships were amended within a logic tree formulation to compute and develop the regional exposure on a set of hazard maps. Hazard contour maps are constructed for peak ground acceleration as well as 0.1-, 0.2-, 0.5-, 1-, and 2-s spectral periods for 100 and 475 years return periods for ground motion on rock. The results illustrate that Egypt is characterized by very low to high seismic activity grading from the west to the eastern part of the country. The uniform hazard spectra are estimated at some important cities distributed allover Egypt. The deaggregation of seismic hazard is estimated at some cities to identify the scenario events that contribute to a selected seismic hazard level. The results of this study can be used in seismic microzonation, risk mitigation, and earthquake engineering purposes.

Multi scenario seismic hazard assessment for Egypt

NASA Astrophysics Data System (ADS)

Mostafa, Shaimaa Ismail; Abd el-aal, Abd el-aziz Khairy; El-Eraki, Mohamed Ahmed

2018-05-01

Egypt is located in the northeastern corner of Africa within a sensitive seismotectonic location. Earthquakes are concentrated along the active tectonic boundaries of African, Eurasian, and Arabian plates. The study area is characterized by northward increasing sediment thickness leading to more damage to structures in the north due to multiple reflections of seismic waves. Unfortunately, man-made constructions in Egypt were not designed to resist earthquake ground motions. So, it is important to evaluate the seismic hazard to reduce social and economic losses and preserve lives. The probabilistic seismic hazard assessment is used to evaluate the hazard using alternative seismotectonic models within a logic tree framework. Alternate seismotectonic models, magnitude-frequency relations, and various indigenous attenuation relationships were amended within a logic tree formulation to compute and develop the regional exposure on a set of hazard maps. Hazard contour maps are constructed for peak ground acceleration as well as 0.1-, 0.2-, 0.5-, 1-, and 2-s spectral periods for 100 and 475 years return periods for ground motion on rock. The results illustrate that Egypt is characterized by very low to high seismic activity grading from the west to the eastern part of the country. The uniform hazard spectra are estimated at some important cities distributed allover Egypt. The deaggregation of seismic hazard is estimated at some cities to identify the scenario events that contribute to a selected seismic hazard level. The results of this study can be used in seismic microzonation, risk mitigation, and earthquake engineering purposes.

Egypt: World Oil Report 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1991-08-01

This paper reports on a selective ban on exploration for oil and gas that resulted for offshore and onshore areas of the Red Sea and South Sinai. Egypt is a new hot spot for environmental concerns. After six months of debate, three concessions in the southern Gulf of Suez were reopened for exploration in late 1990. Companies can resume seismic work and eventually drill, but only in a zone from the shoreline inland and under certain restrictions. If oil is found in the restricted area, discovery wells must be plugged and the location restored. If commercial, companies must go outsidemore » the restricted zone and drill deviated wells. Three companies directly involved are Asamera Egypt (Gulf Canada), Germany's Deminex and Exxon. All foreign exploration companies are now required to submit environmental impact statements.« less

Origin and distribution of desert ants across the Gibraltar Straits.

PubMed

Villalta, Irene; Amor, Fernando; Galarza, Juan A; Dupont, Simon; Ortega, Patrocinio; Hefetz, Abraham; Dahbi, Abdallah; Cerdá, Xim; Boulay, Raphaël

2018-01-01

The creation of geographic barriers has long been suspected to contribute to the formation of new species. We investigated the phylogeography of desert ants in the western Mediterranean basin in order to elucidate their mode of diversification. These insects which have a low dispersal capacity are recently becoming important model systems in evolutionary studies. We conducted an extensive sampling of species belonging to the Cataglyphis albicans group in the Iberian Peninsula (IP) and the northern Morocco (North Africa; NA). We then combined genetic, chemical and morphological analyses. The results suggest the existence of at least three and five clades in the IP and NA, respectively, whose delineation partially encompass current taxonomic classification. The three Iberian clades are monophyletic, but their origin in NA is uncertain (79% and 22% for Bayesian and Maximum Likelihood support, respectively). The estimation of divergence time suggests that a speciation process was initiated after the last reopening of the Gibraltar Straits ≈5.33 Ma. In the IP, the clades are parapatric and their formation may have been triggered by the fragmentation of a large population during the Pleistocene due to extended periods of glaciation. This scenario is supported by demographic analyses pointing at a recent expansion of Iberian populations that contrasts with the progressive contraction of the NA clades. Niche modeling reveals that this area, governed by favorable climatic conditions for desert ants, has recently increased in the IP and decreased in NA. Altogether, our data points at geoclimatic events as major determinants of species formation in desert ants, reinforcing the role of allopatric speciation. Copyright © 2017 Elsevier Inc. All rights reserved.

Simulated climate effects of desert irrigation geoengineering

PubMed Central

Cheng, Wei; Moore, John C.; Cao, Long; Ji, Duoying; Zhao, Liyun

2017-01-01

Geoengineering, the deliberate large-scale manipulation of earth’s energy balance to counteract global warming, is an attractive proposition for sparsely populated deserts. We use the BNU and UVic Earth system models to simulate the effects of irrigating deserts under the RCP8.5 scenario. Previous studies focused on increasing desert albedo to reduce global warming; in contrast we examine how extending afforestation and ecological projects, that successfully improve regional environments, fair for geoengineering purposes. As expected desert irrigation allows vegetation to grow, with bare soil or grass gradually becoming shrub or tree covered, with increases in terrestrial carbon storage of 90.3 Pg C (UVic-ESCM) – 143.9 Pg C (BNU-ESM). Irrigating global deserts makes the land surface temperature decrease by 0.48 °C and land precipitation increase by 100 mm yr−1. In the irrigated areas, BNU-ESM simulates significant cooling of up to 4.2 °C owing to the increases in low cloud and latent heat which counteract the warming effect due to decreased surface albedo. Large volumes of water would be required to maintain global desert irrigation, equivalent 10 mm/year of global sea level (BNU-ESM) compensate for evapotranspiration losses. Differences in climate responses between the deserts prompt research into tailored albedo-irrigation schemes. PMID:28418005

Rocks, climate and the survival of human societies in hyper-arid and arid environments - Are the human civilization in deserts at a permanent risk of collapse?

NASA Astrophysics Data System (ADS)

Yoav, Avni; Noa, Avriel-Avni

2017-04-01

The great challenges of living in the arid and hyper arid regions worldwide are the shortage of water, limited resources and the permanent uncertainty of the desert climate. These challenges are known as the main weaknesses of desert societies that are prone, according to the existing paradigm, to a permanent risk of collapse. However, in the Middle East deserts, human societies are known since prehistoric times and during the entire hyper-dry Holocene. This hints that the simple paradigm of desert societies' high vulnerability to harsh desert environments needs to be better examined. In this context we examine three case studies: 1. The Southern Sinai region in Egypt: In this region, the annual precipitation fluctuates between 20-50 mm/y. However, in this highly mountainous area, desert agriculture plots including orchards were constructed, located mainly around the byzantine monastery of Santa Katerina. During the last 1500 years, much of the water supply needed for humans and agriculture was generated from runoff developed on exposed granite rocks. 2. The southern Jordan region south of Petra: Much of this wide area connecting the deserts of the Arabian Peninsula and southern Jordan receive only 20-30 mm/y. However, the main caravan route established by the Arabian tribes during the first millennia BC managed to cross this land, supplying the water needs of many camels. Most of this water was stored in large cisterns dug into the sandstone rock formations exposed along the route, especially within the Disi Formation. 3. The Negev Highlands of southern Israel: This region is divided between the hyper arid region to the south, receiving 70-80 mm/y, and the arid region to the north receiving 90-130 mm/y. During the last two millennia, the hyper arid area was used for camel grazing and goats herds, while the northern sector was used for the construction of agriculture plots, agriculture farms and even desert towns. All these activities were sustained by runoff

Opportunities for woody crop production using treated wastewater in Egypt. I. Afforestation strategies

Treesearch

Ronald S. Zalesny Jr.; John A. Stanturf; Steven R. Evett; Nabil F. Kandil; Christopher Soriano

2011-01-01

The Nile River provides nearly 97% of Egypt's freshwater supply. Egypt's share of Nile waters is fixed at 55.5 billion cubic meters annually. As a result, Egypt will not be able to meet increasing water demand using freshwater from the Nile and has been developing non-conventional wastewater reuse strategies to meet future demands. The USAID Mission in Cairo...

Student Academic Freedom in Egypt: Perceptions of University Education Students

ERIC Educational Resources Information Center

Zain-Al-Dien, Muhammad M.

2016-01-01

The purpose of the present study was to investigate student academic freedom from the university education students' point of view in Egypt. This study adopted a survey research design in which the questionnaire was the main data collection instrument. The study participants comprised 800 university education students in Egypt. The result of the…

Meningeal Preservation in a Child Mummy from Ancient Egypt.

PubMed

Isidro, Albert; Herrerin, Jesús

2017-04-01

Over many centuries, the ancient Egyptians developed a method of preserving bodies so they would remain lifelike. Mummification of bodies was originally a natural process in Egypt, and it evolved to a sophisticated embalming system to preserve the individual for the afterlife. Afterwards, mummification continued to be practiced in Egypt for some 3000 years, lasting until the end of the Christian era. In the Coptic necropolis of Qarara (Middle Egypt), 17 mummified individuals were studied during the 2012 campaign. One of them was a 6-8 old-year male child with a damaged skull that allowed us to see the meningeal structures covering the entire cranial vault, in absence of brain remains. This finding in a child mummy is exceptional, as reflected in the specialized literature. Copyright © 2017 Elsevier Inc. All rights reserved.

Seasonal metabolic acclimatization in the herbivorous desert lizard Uromastyx philbyi (Reptilia: Agamidea) from western Saudi Arabia.

PubMed

Zari, Talal A

2016-08-01

Many ectotherms adjust their metabolic rate seasonally in association with variations in environmental temperatures. The range and direction of these seasonal changes in reptilian metabolic rates are thought to be linked to the seasonality of activity and energy requirements. The present study was conducted to measure the standard metabolic rate (SMR) of seasonally-acclimatized Uromastyx philbyi with different body masses at 20, 25, 30, 35 and 40°C using open-flow respirometry during the four seasons. SMR was mass-dependent. The mean exponent of mass, "b", in the metabolism-body mass relation was 0.76 (variance=0.0007). Likewise, SMR increased as temperature increased with low Q10 values at high temperatures and high Q10 values at low temperatures. The lowest and highest Q10 values were achieved for temperature ranges of 30-35°C for summer-acclimatized dhabbs (Q10=1.6) and 20-25°C for winter-acclimatized dhabbs (Q10=3.9). Seasonal acclimatization effects were obvious at all temperatures (20-40°C). Winter-acclimatized dhabbs had the lowest metabolic rates at all temperatures. The seasonal acclimatization patterns displayed by U. philbyi may represent a valuable adaptation for herbivorous desert lizards that inhabit subtropical deserts to facilitate activity during their active seasons and to conserve energy during inactivity at low temperatures. Copyright © 2016 Elsevier Ltd. All rights reserved.

History, etymology, and fallacy: attitudes toward male masturbation in the ancient Western world.

PubMed

Elia, J P

1987-01-01

This article examines the attitudes toward male masturbation in the ancient western world. More specifically, this work deals with ancient Egypt, Greece, and Rome. By comparing each epoch and geographic region, intolerance of autoerotic activity can be seen. Although there is a pattern of intolerance, the act of masturbation is always viewed provisionally. In addition, by examining these three periods of history not only can attitudes be scrutinized, but also it can be seen quite clearly that there was no golden age of sexuality: The attitude of accepted and encouraged unlimited and varied sexual practices does not exist in the ancient western world. As in many other cultures in various stages of history, procreative sexuality is the dominating theme. Thus, current attitudes of sex are derived from, and still survive due to the influence of, ancient western civilization.

Entropy of Egypt's virtual water trade gravity field

NASA Astrophysics Data System (ADS)

Karakatsanis, Georgios; Bierbach, Sandra

2016-04-01

The study investigates the entropy of Egypt's virtual water trade gravity distribution, in order to provide a chart of Egypt's embodied water balance in agricultural trade, in relation to distances with its major counterparties. Moreover, our calculations on the amount of the embodied water traded between Egypt and each of its partners take place according to a combination of available data on the blue, green and grey water footprints as well as the Food and Agriculture Organization (FAO) database of traded amounts per crop type. A study on the virtual water trade gravity, enables us to enrich former related studies (Fracasso 2014; Fracasso, Sartori and Schiavo 2014) via examining Egypt's water supply dependence on the Nile River and if comparative advantages -purely from the side of water quantities- can be identified via recognizing which water footprint categories are particularly high. Additionally, this methodology can comprise -from a fundamental level- a guide for revealing the importance of water footprint types for Egypt's agricultural sector; hence, Egypt's potential comparative advantages, as far as quantitative water endowments are exclusively concerned (without consideration of water or crop prices). Although it is pointed out very correctly by various authors (Antonelli and Sartori 2014) that the virtual water trade concept does not incorporate many important aspects of water supply -such as heavy water price subsidizing- to be used accurately for the identification of comparative advantages, we consider that the purely quantitative examination can provide strong fundamental indications -especially for green and grey water footprints, which are hypothesized to be less sensitive to subsidizing. In overall, this effect can very well provide a primary indication on the organization of the global alimentation trade network (Yang et al. 2006). The gravity equation used contains water footprint data for the 15 top traded crops and the distances for Egypt

Validation of the McClear clear-sky model in desert conditions with three stations in Israel

NASA Astrophysics Data System (ADS)

Lefèvre, Mireille; Wald, Lucien

2016-03-01

The new McClear clear-sky model, a fast model based on a radiative transfer solver, exploits the atmospheric properties provided by the EU-funded Copernicus Atmosphere Monitoring Service (CAMS) to estimate the solar direct and global irradiances received at ground level in cloud-free conditions at any place any time. The work presented here focuses on desert conditions and compares the McClear irradiances to coincident 1 min measurements made in clear-sky conditions at three stations in Israel which are distant from less than 100 km. The bias for global irradiance is comprised between 2 and 32 W m-2, i.e. between 0 and 4 % of the mean observed irradiance (approximately 830 W m-2). The RMSE ranges from 30 to 41 W m-2 (4 %) and the squared correlation coefficient is greater than 0.976. The bias for the direct irradiance at normal incidence (DNI) is comprised between -68 and +13 W m-2, i.e. between -8 and 2 % of the mean observed DNI (approximately 840 W m-2). The RMSE ranges from 53 (7 %) to 83 W m-2 (10 %). The squared correlation coefficient is close to 0.6. The performances are similar for the three sites for the global irradiance and for the DNI to a lesser extent, demonstrating the robustness of the McClear model combined with CAMS products. These results are discussed in the light of those obtained by McClear for other desert areas in Egypt and United Arab Emirates.

Geophysical Investigations of the Smoke Creek Desert and their Geologic Implications, Northwest Nevada and Northeast California

USGS Publications Warehouse

Ponce, David A.; Glen, Jonathan M.G.; Tilden, Janet E.

2006-01-01

The Smoke Creek Desert is a large basin about 100 km (60 mi) north of Reno near the California-Nevada border, situated along the northernmost parts of the Walker Lane Belt, a physiographic region defined by diverse topographic expression consisting of northweststriking topographic features and strike-slip faulting. Because geologic and geophysical framework studies play an important role in understanding the hydrogeology of the Smoke Creek Desert, a geophysical effort was undertaken to help determine basin geometry, infer structural features, and estimate depth to basement. In the northernmost parts of the Smoke Creek Desert basin, along Squaw Creek Valley, geophysical data indicate that the basin is shallow and that granitic rocks are buried at shallow depths throughout the valley. These granitic rocks are faulted and fractured and presumably permeable, and thus may influence ground-water resources in this area. The Smoke Creek Desert basin itself is composed of three large oval sub-basins, all of which reach depths to basement of up to about 2 km (1.2 mi). In the central and southern parts of the Smoke Creek Desert basin, magnetic anomalies form three separate and narrow EW-striking features. These features consist of high-amplitude short-wavelength magnetic anomalies and probably reflect Tertiary basalt buried at shallow depth. In the central part of the Smoke Creek Desert basin a prominent EW-striking gravity and magnetic prominence extends from the western margin of the basin to the central part of the basin. Along this ridge, probably composed of Tertiary basalt, overlying unconsolidated basin-fill deposits are relatively thin (< 400 m). The central part of the Smoke Creek Desert basin is also characterized by the Mid-valley fault, a continuous geologic and geophysical feature striking NS and at least 18-km long, possibly connecting with faults mapped in the Terraced Hills and continuing southward to Pyramid Lake. The Mid-valley fault may represent a lateral

Satellite Observations of Desert Dust-induced Himalayan Snow Darkening

NASA Technical Reports Server (NTRS)

Gautam, Ritesh; Hsu, N. Christina; Lau, William K.-M.; Yasunari, Teppei J.

2013-01-01

The optically thick aerosol layer along the southern edge of the Himalaya has been subject of several recent investigations relating to its radiative impacts on the South Asian summer monsoon and regional climate forcing. Prior to the onset of summer monsoon, mineral dust from southwest Asian deserts is transported over the Himalayan foothills on an annual basis. Episodic dust plumes are also advected over the Himalaya, visible as dust-laden snow surface in satellite imagery, particularly in western Himalaya. We examined spectral surface reflectance retrieved from spaceborne MODIS observations that show characteristic reduction in the visible wavelengths (0.47 nm) over western Himalaya, associated with dust-induced solar absorption. Case studies as well as seasonal variations of reflectance indicate a significant gradient across the visible (0.47 nm) to near-infrared (0.86 nm) spectrum (VIS-NIR), during premonsoon period. Enhanced absorption at shorter visible wavelengths and the resulting VIS-NIR gradient is consistent with model calculations of snow reflectance with dust impurity. While the role of black carbon in snow cannot be ruled out, our satellite-based analysis suggests the observed spectral reflectance gradient dominated by dust-induced solar absorption during premonsoon season. From an observational viewpoint, this study underscores the importance of mineral dust deposition toward darkening of the western Himalayan snow cover, with potential implications to accelerated seasonal snowmelt and regional snow albedo feedbacks.

Separate but Equal: Segregated Religious Education in Egypt's Public Schools

ERIC Educational Resources Information Center

Isaac, John

2012-01-01

The Arab Spring exposed the hidden secrets of Egyptian society to the global community. In spite of the insatiable media attention paid to the Mubarak regime and the toll it took on the entire country, Egypt's education system received little attention. For decades, Egypt's public schools have forced students to attend segregated classes, based on…

The rise in stunting in relation to avian influenza and food consumption patterns in Lower Egypt in comparison to Upper Egypt: results from 2005 and 2008 Demographic and Health Surveys.

PubMed

Kavle, Justine A; El-Zanaty, Fatma; Landry, Megan; Galloway, Rae

2015-03-25

A 2006 avian influenza (AI) outbreak resulted in mass removal of chickens in Lower Egypt, which decreased the household supply of poultry. Poultry, a key animal-source food, contains nutrients critical for child growth. This paper examines determinants of stunting between 2006 and 2008 in children 6 to 59 months of age within the context of the AI outbreak. The 2005 and 2008 nationally representative Egypt Demographic and Health Surveys (EDHS) were used to analyse anthropometric data from 7,794 children in 2005 and 6,091 children in 2008. Children, 6-59 months of age, with length for age Z-score < -2 S.D. were categorized as stunted. Predictors of stunting were examined by bivariate and multivariable analyses, focusing on Lower Egypt, where a rise in stunting occurred, and Upper Egypt, where stunting declined. Between 2005 and 2008, Upper Egypt experienced a significant decline in stunting (28.8 to 21.8%, P < 0.001). Lower Egypt experienced a significant rise in stunting (16.6 to 31.5%, P < 0.001), coinciding with the 2006 AI outbreak. In Lower Egypt (2008), households owning poultry were 41.7% less likely to have a stunted child [aOR 0.58; 95% CI (0.42, 0.81) P = 0.002], and 12-47 month old children were 2.12-2.34 times [95% CI (1.39 - 3.63) P ≤ 0.001] more likely to be stunted than 6-11 month old children. Older children were likely affected by AI, as these children were either in-utero or toddlers in 2006. In Upper Egypt, stunting peaked at 12-23 months [aOR 2.62, 95% CI (1.73-3.96), P < 0.001], with lowered risk (22-32%) of stunting in 24-47 month old children [aOR1.65, 95% 1.07-2.53, P = 0.022, 24-35 month old] and [aOR 1.57, 95% CI 1.01-2.43, P = 0.043 36-47 months old]. A two-fold increase in child consumption of sugary foods between 2005 and 2008 was found in Lower Egypt (24.5% versus 52.7%; P < .001). Decreased dietary diversity, reduced poultry consumption, substitution of nutritious foods with sugary foods paralleled a reduction in household raising of

Desert Amplification in a Warming Climate

PubMed Central

Zhou, Liming

2016-01-01

Here I analyze the observed and projected surface temperature anomalies over land between 50°S-50°N for the period 1950–2099 by large-scale ecoregion and find strongest warming consistently and persistently seen over driest ecoregions such as the Sahara desert and the Arabian Peninsula during various 30-year periods, pointing to desert amplification in a warming climate. This amplification enhances linearly with the global mean greenhouse gases(GHGs) radiative forcing and is attributable primarily to a stronger GHGs-enhanced downward longwave radiation forcing reaching the surface over drier ecoregions as a consequence of a warmer and thus moister atmosphere in response to increasing GHGs. These results indicate that desert amplification may represent a fundamental pattern of global warming associated with water vapor feedbacks over land in low- and mid- latitudes where surface warming rates depend inversely on ecosystem dryness. It is likely that desert amplification might involve two types of water vapor feedbacks that maximize respectively in the tropical upper troposphere and near the surface over deserts, with both being very dry and thus extremely sensitive to changes of water vapor. PMID:27538725

Assessment and management of water resources in Egypt to face drought and water scarcity

NASA Astrophysics Data System (ADS)

Wolters, Wouter; El Guindy, Samia; Salah El Deen, Magdy; Roest, Koen; Smit, Robert; Froebrich, Jochen

2013-04-01

Egypt is one of the countries hardest hit by global and climate change. Challenges include population growth; increased demands for food, water, and energy; as well as changing land use patterns and urbanization. Egypt's part of the Mediterranean is characterized by a very complex hydrological system, as it lacks rainfall (Cairo average 30 mm/year) and it is completely dependent on the Nile river flow. The growth of the Egyptian population and its economy in the near future leads to an increase in the demand for water and the overall water allocation priority basically is: first drinking water, then industry, and whatever is remaining will be available for agriculture and nature. Because the agricultural sector uses more than 80 per cent of available water, the main option available to reduce water scarcity in the priority sectors of the economy is to allocate less to the agriculture sector. Scientifically based advances in facing future drought and water scarcity through innovations increasing yields and food security by measures leading to "more crop per drop" are required. New and modern large- and medium-scale agriculture is being developed in desert areas with participation of the private sector for investments. To prepare the farming community and others elsewhere, for the future situation of water shortages, a paradigm shift is needed. New farming systems under tight water supply conditions are in development to prepare for a future with less water. Egyptian farming systems need a major transition to prevent further marginalization of agriculture, which would also have a major impact on food security. Central to this transition should be the increase of value generated per volume available water, also referred to as "more crop per drop" or "more cash per splash". There is room for the urgently required improvement: the present return on water in agriculture in Egypt is about US 0.25 /m3, where values of over US 1 /m3 are "easily" reached elsewhere. Moreover

Serious fungal infections in Egypt.

PubMed

Zaki, S M; Denning, D W

2017-06-01

We aimed to estimate the burden of serious fungal infections in Egypt, currently unknown, based on the size of the populations at risk and available epidemiological data. Data were obtained from the World Health Organization (WHO), the Joint United Nations Programme on HIV/AIDS (UNAIDS), and published reports with clearcut denominators. When no data existed, risk populations were used to estimate frequencies of fungal infections, using previously described methodology. The population of Egypt in 2011 was ∼82,500,000; 31% children, and 8% women >60 years of age. Amongst about 21.8 million women aged 15-50 years, recurrent vulvovaginal candidiasis (≥4 episodes/year) is estimated to occur in 1.3 million (3,169/100,000 females). Using a low international average rate of 5/100,000, we estimate 4,127 cases of candidaemia, and 619 patients with intra-abdominal candidiasis. Amongst the survivors of pulmonary tuberculosis (TB) in Egypt in 2012, 319 new cases of chronic pulmonary aspergillosis (CPA) are likely, a prevalence of 1,005 post-TB and a total prevalence estimate of 3,015 CPA patients in all. Asthma is common in Egypt, affecting 9.4% of adults, 5.35 million, and so ABPA and SAFS were estimated in around 162/100,000 and 214/100,000 respectively. Invasive aspergillosis is estimated to affect 495 patients following leukaemia therapy, there are an estimated 37 cases in renal and liver transplant recipients, and an estimated 132 patients develop IA in the context of lung cancer. Amongst 641,000 COPD admissions to hospital each year, 8,337 patients develop IA. The total HIV-infected population is small, with an estimated 6,500 patients, 2,500 not on antiretroviral therapy. Amongst HIV-infected patients, 38 (0.6%) cases of cryptococcal meningitis and 125 (1.9%) cases of Pneumocystis pneumonia are estimated each year. Fungal keratitis is common, with 28-55% (mean 40%) of corneal infections being fungal, an estimated total of 11,550 cases. The present study indicates

Under-canopy microclimate within sand dunes in the Negev Desert

NASA Astrophysics Data System (ADS)

Kidron, Giora J.

2010-10-01

SummaryScattered shrubs are a common phenomenon in many arid landscapes. Once established, shrubs are known to create "islands of fertility", i.e., preferential habitats for annuals and animals. In an attempt to characterize the physical conditions prevailing under the shrub, radiation, temperatures and soil moisture (0-40 cm) following rain were measured during 1993-1995 at the shaded under-canopy (UC) and at the exposed inter-shrub habitat (EXP) of two pairs of shrubs located at the north- and south-facing slopes of dunes in the Nizzana research site, western Negev Desert, Israel. In addition, the soil organic matter (SOM) and the fine (silt and clay) content (FC) were also measured. Whereas the differences in the amounts of SOM and FC were small, daylight temperatures at UC were substantially lower (6-15 °C), subsequently resulting in extended time during which the UC habitat remained wet. Moisture was retained for up to 10.5-42.6% longer at UC in comparison to EXP, mainly explained by the shading effect. SOM was found to explain only 8.6-19.6% of the results. By shading, shrubs in the Negev Desert may thus provide relatively wetter conditions for annuals, rendering them an advantage over inter-shrub habitats at this harsh arid environment.

Burden of stroke in Egypt: current status and opportunities.

PubMed

Abd-Allah, Foad; Moustafa, Ramez Reda

2014-12-01

Middle East and North Africa (MENA) countries have a diversity of populations with similar life style, dietary habits, and vascular risk factors that may influence stroke risk, prevalence, types, and disease burden. Egypt is the most populated nation in the Middle East with an estimated 85.5 million people. In Egypt, according to recent estimates, the overall prevalence rate of stroke is high with a crude prevalence rate of 963/100,000 inhabitants. In spite of disease burden, yet there is a huge evidence practice gap. The recommended treatments for ischemic stroke that are guideline include systematic supportive care in a stroke unit or stroke center is still deficient. In addition, the frequency of thrombolysis in Egypt is very low for many reasons; the major one is that the health insurance system is not covering thrombolysis therapy in nonprivate sectors so patients must cover the costs using their own personal savings; otherwise, they will not receive treatment. Another important factor is the pronounced delay in prehospital and in hospital management of acute stroke. Improvement of stroke care in Egypt should be achieved through multi and interdisciplinary approach including public awareness, physicians' education, and synergistic approach to stroke care with Emergency Medical System. © 2014 World Stroke Organization.

How desert varnish forms?

NASA Astrophysics Data System (ADS)

Perry, Randall S.; Kolb, Vera M.; Lynne, Bridget Y.; Sephton, Mark A.; Mcloughlin, Nicola; Engel, Michael H.; Olendzenski, Lorraine; Brasier, Martin; Staley, James T., Jr.

2005-09-01

Desert varnish is a black, manganese-rich rock coating that is widespread on Earth. The mechanism underlying its formation, however, has remained unresolved. We present here new data and an associated model for how desert varnish forms, which substantively challenges previously accepted models. We tested both inorganic processes (e.g. clays and oxides cementing coatings) and microbial methods of formation. Techniques used in this preliminary study include SEM-EDAX with backscatter, HRTEM of focused ion beam prepared (FIB) wafers and several other methods including XRPD, Raman spectroscopy, XPS and Tof-SIMS. The only hypothesis capable of explaining a high water content, the presence of organic compounds, an amorphous silica phase (opal-A) and lesser quantities of clays than previously reported, is a mechanism involving the mobilization and redistribution of silica. The discovery of silica in desert varnish suggests labile organics are preserved by interaction with condensing silicic acid. Organisms are not needed for desert varnish formation but Bacteria, Archaea, Eukarya, and other organic compounds are passively incorporated and preserved as organominerals. The rock coatings thus provide useful records of past environments on Earth and possibly other planets. Additionally this model also helps to explain the origin of key varnish and rock glaze features, including their hardness, the nature of the "glue" that binds heterogeneous components together, its layered botryoidal morphology, and its slow rate of formation.

Lessons from the Desert

DTIC Science & Technology

1993-04-14

involvement in Operations DESERT SHIELD and STORM. The 498th was a unique unit, well-suited for the gamut of operations conducted by the 2AD (FWD) during its...Division (Forward), during that unit’s involvement in Operations DESERT SHIELD and STORM. The 498th was a unique unit, well-suited for the gamut of...well-suited fir the gamut of operations conducted by 2AD (FWD) during its stay in Southwest Asia (SWA) . I commanded the 498th Support Battalion from

The eco-epidemiology of Triatoma infestans in the temperate Monte Desert ecoregion of mid-western Argentina

PubMed Central

Carbajal-de-la-Fuente, Ana Laura; Provecho, Yael Mariana; Fernández, María del Pilar; Cardinal, Marta Victoria; Lencina, Patricia; Spillmann, Cynthia; Gürtler, Ricardo Esteban

2017-01-01

BACKGROUND The eco-epidemiological status of Chagas disease in the Monte Desert ecoregion of western Argentina is largely unknown. We investigated the environmental and socio-demographic determinants of house infestation with Triatoma infestans, bug abundance, vector infection with Trypanosoma cruzi and host-feeding sources in a well-defined rural area of Lavalle Department in the Mendoza province. METHODS Technical personnel inspected 198 houses for evidence of infestation with T. infestans, and the 76 houses included in the current study were re-inspected. In parallel with the vector survey, an environmental and socio-demographic survey was also conducted. Univariate risk factor analysis for domiciliary infestation was carried out using Firth penalised logistic regression. We fitted generalised linear models for house infestation and bug abundance. Blood meals were tested with a direct ELISA assay, and T. cruzi infection was determined using a hot-start polymerase chain reaction (PCR) targeting the kinetoplast minicircle (kDNA-PCR). FINDINGS The households studied included an aged population living in precarious houses whose main economic activities included goat husbandry. T. infestans was found in 21.2% of 198 houses and in 55.3% of the 76 re-inspected houses. Peridomestic habitats exhibited higher infestation rates and bug abundances than did domiciles, and goat corrals showed high levels of infestation. The main host-feeding sources were goats. Vector infection was present in 10.2% of domiciles and 3.2% of peridomiciles. Generalised linear models showed that peridomestic infestation was positively and significantly associated with the presence of mud walls and the abundance of chickens and goats, and bug abundance increased with the number of all hosts except rabbits. MAIN CONCLUSIONS We highlight the relative importance of specific peridomestic structures (i.e., goat corrals and chicken coops) associated with construction materials and host abundance as

A new genus and species of marine catfishes (Siluriformes; Ariidae) from the upper Eocene Birket Qarun Formation, Wadi El-Hitan, Egypt.

PubMed

El-Sayed, Sanaa E; Kora, Mahmoud A; Sallam, Hesham M; Claeson, Kerin M; Seiffert, Erik R; Antar, Mohammed S

2017-01-01

Wadi El-Hitan, the UNESCO World Heritage Site, of the Fayum Depression in the northeast part of the Western Desert of Egypt, has produced a remarkable collection of Eocene vertebrates, in particular the fossil whales from which it derives its name. Here we describe a new genus and species of marine catfishes (Siluriformes; Ariidae), Qarmoutus hitanensis, from the base of the upper Eocene Birket Qarun Formation, based on a partial neurocranium including the complete left side, partial right dentary, left suspensorium, two opercles, left pectoral girdle and spine, nuchal plates, first and second dorsal spines, Weberian apparatus and a disassociated series of abdominal vertebrae. All of the elements belong to the same individual and some of them were found articulated. Qarmoutus gen. nov. is the oldest and the most complete of the Paleogene marine catfishes unearthed from the Birket Qarun Formation. The new genus exhibits distinctive features not seen in other African Paleogene taxa, such as different sculpturing on the opercle and pectoral girdle with respect to that on the neurocranium and nuchal plates, denticulate ornamentation on the skull bones arranged in longitudinal rows and forming a radiating pattern on the sphenotic, pterotic, extrascapular and the parieto-supraoccipital, indentations or pitted ornamentation on the nuchal plates as well as the parieto-supraoccipital process, strut-like radiating pattern of ornamentation on the opercle from the proximal articulation to margins, longitudinal, curved, reticulate ridges and tubercular ornamentations on the cleithrum, sinuous articulation between the parieto-supraoccipital process and the anterior nuchal plate, long, narrow, and arrowhead shaped nuchal shield, very small otic capsules restricted to the prootic. Multiple parsimony and Bayesian morphological phylogenetic analyses of Ariidae, run with and without "molecular scaffolds", yield contradictory results for the placement of Qarmoutus; the genus is either

Geometeorological data collected by the USGS Desert Winds Project at Gold Spring, Great Basin desert, northeastern Arizona, 1979-1992

USGS Publications Warehouse

Helm, P.J.; Breed, C.S.; Tigges, R.K.; Garcia, P.A.

1995-01-01

The primary purpose of the Desert Winds Project (DWP) is to obtain high-resolution meteorological data and related surface geological and vegetation data for natural (e.g., uncultivated) desert sites where wind is or has been a major erosive or depositional force. The objectives are twofold: (1) to provide the detailed field measurements needed to carry out quantitative studies of wind as an agent of surface geologic change; and (2) to establish a baseline for defining the 'normal' range of climatic conditions that can be expected to occur on a decadal time scale, in areas considered representative of the major American deserts. The Gold Spring locality was selected to represent that part of the Great Basin Desert that extends into northeastern Arizona. The long-term goal for acquiring and analyzing the Desert Winds Project data is to use them to address problems of land resource degradation by wind, whether resulting from climatic variation aridification) or human activities (desertification), or both (see techinfo.doc).

Late Quaternary history of the Atacama Desert

USGS Publications Warehouse

Latorre, Claudio; Betancourt, Julio L.; Rech, Jason A.; Quade, Jay; Holmgren, Camille; Placzek, Christa; Maldonado, Antonio; Vuille, Mathias; Rylander, Kate A.; Smith, Mike; Hesse, Paul

2005-01-01

Of the major subtropical deserts found in the Southern Hemisphere, the Atacama Desert is the driest. Throughout the Quaternary, the most pervasive climatic influence on the desert has been millennial-scale changes in the frequency and seasonality of the scant rainfall, and associated shifts in plant and animal distributions with elevation along the eastern margin of the desert. Over the past six years, we have mapped modern vegetation gradients and developed a number of palaeoenvironmental records, including vegetation histories from fossil rodent middens, groundwater levels from wetland (spring) deposits, and lake levels from shoreline evidence, along a 1200-kilometre transect (16–26°S) in the Atacama Desert. A strength of this palaeoclimate transect has been the ability to apply the same methodologies across broad elevational, latitudinal, climatic, vegetation and hydrological gradients. We are using this transect to reconstruct the histories of key components of the South American tropical (summer) and extratropical (winter) rainfall belts, precisely at those elevations where average annual rainfall wanes to zero. The focus has been on the transition from sparse, shrubby vegetation (known as the prepuna) into absolute desert, an expansive hyperarid terrain that extends from just above the coastal fog zone (approximately 800 metres) to more than 3500 metres in the most arid sectors in the southern Atacama.

Phytoremediation for Oily Desert Soils

NASA Astrophysics Data System (ADS)

Radwan, Samir

This chapter deals with strategies for cleaning oily desert soils through rhizosphere technology. Bioremediation involves two major approaches; seeding with suitable microorganisms and fertilization with microbial growth enhancing materials. Raising suitable crops in oil-polluted desert soils fulfills both objectives. The rhizosphere of many legume and non-legume plants is richer in oil-utilizing micro-organisms than non-vegetated soils. Furthermore, these rhizospheres also harbour symbiotic and asymbiotic nitrogen-fixing bacteria, and are rich in simple organic compounds exuded by plant roots. Those exudates are excellent nutrients for oil-utilizing microorganisms. Since many rhizospheric bacteria have the combined activities of hydrocarbon-utilization and nitrogen fixation, phytoremediation provides a feasible and environmentally friendly biotechnology for cleaning oil-polluted soils, especially nitrogen-poor desert soils.

Origin of desert loess from some experimental observations

NASA Technical Reports Server (NTRS)

Whalley, W. B.; Smith, B. J.; Marshall, J. R.

1982-01-01

The aeolian attrition of angular quartz grains previously produced by weathering in deserts has been simulated, yielding abrasion products which show that both coarse and fine silt sizes are produced by this process. These results suggest that desert aeolian processes can produce loess, and it is speculated that while much of this material from many deserts has been deposited in the sea, the Chinese loess could have been produced in the Gobi desert. The finest of the particles produced by such attrition may serve as a source of silica for silcrete formation.

Power and Gender in Ancient Egypt: The Case of Hatshepsut

ERIC Educational Resources Information Center

Hilliard, Kristina; Wurtzel, Kate

2009-01-01

Hatshepsut (1479-1458 B.C.E) ruled New Kingdom Egypt for roughly 20 years as one of the few female pharaohs in the history of ancient Egypt. Her rule began when her husband died and her stepson was too young to be pharaoh. To legitimize her role as pharaoh, Hatshepsut began a significant building campaign by constructing numerous images, temples,…

Community-Based Education in Egypt: Is It Achieving Its Stated Goals?

ERIC Educational Resources Information Center

Langsten, Ray

2016-01-01

Egypt promises "education for all". Primary attendance and completion have increased substantially. Still, many children remain out of school. There remain questions about the quality of education. Since the early 1990s, community-based education (CBE) has been part of Egypt's educational programme. Community-based education is meant to…

77 FR 24555 - Determination on Foreign Military Financing Assistance for Egypt

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-24

... DEPARTMENT OF STATE [Public Notice 7853] Determination on Foreign Military Financing Assistance for Egypt Pursuant to section 7041(a)(1)(C) of the Department of State, Foreign Operations, and... 7041(a)(1)(B) of the Act with respect to the provision of Foreign Military Financing for Egypt, and I...

Application of LANDSAT satellite imagery for iron ore prospecting in the western desert of Egypt

NASA Technical Reports Server (NTRS)

Elshazly, E. M.; Abdel-Hady, M. A.; Elghawaby, M. A.; Khawasik, S. M. (Principal Investigator)

1977-01-01

The author has identified the following significant results. The delineation of the geological units and geological structures through image interpretation, corroborated by field observations and structural analysis, led to the discovery of new iron ore deposits. A new locality for iron ore deposition, namely Gebel Qalamun, was discovered, as well as new occurrences within the already known iron ore region of Bahariya Oasis.

Gopherus agassizii (Desert Tortoise). Non-native seed dispersal

USGS Publications Warehouse

Ennen, J.R.; Loughran, Caleb L.; Lovich, Jeffrey E.

2011-01-01

Sahara Mustard (Brassica tournefortii) is a non-native, highly invasive weed species of southwestern U.S. deserts. Sahara Mustard is a hardy species, which flourishes under many conditions including drought and in both disturbed and undisturbed habitats (West and Nabhan 2002. In B. Tellman [ed.], Invasive Plants: Their Occurrence and Possible Impact on the Central Gulf Coast of Sonora and the Midriff Islands in the Sea of Cortes, pp. 91–111. University of Arizona Press, Tucson). Because of this species’ ability to thrive in these habitats, B. tournefortii has been able to propagate throughout the southwestern United States establishing itself in the Mojave and Sonoran Deserts in Arizona, California, Nevada, and Utah. Unfortunately, naturally disturbed areas created by native species, such as the Desert Tortoise (Gopherus agassizii), within these deserts could have facilitated the propagation of B. tournefortii. (Lovich 1998. In R. G. Westbrooks [ed.], Invasive Plants, Changing the Landscape of America: Fact Book, p. 77. Federal Interagency Committee for the Management of Noxious and Exotic Weeds [FICMNEW], Washington, DC). However, Desert Tortoises have never been directly observed dispersing Sahara Mustard seeds. Here we present observations of two Desert Tortoises dispersing Sahara Mustard seeds at the interface between the Mojave and Sonoran deserts in California.

Food deserts and nutritional risk in Paraguay.

PubMed

Gartin, Meredith

2012-01-01

The purpose of this case study in San Lorenzo, Paraguay is to identify a food desert in a developing context and to test if food deserts shape residential obesity risk. This article reviews some of the debate surrounding whether food deserts really exist; and, if so, what are the dietary implications of living in a food desert. The research is an exploratory/explanatory design. The author mapped the downtown food retail district and the neighborhood food environment to identify what stores/markets. The author assessed each type of food store using an adapted version of the Nutrition Environment Measure Survey for Stores (NEMS-S) for Paraguay. Body mass index and household characteristics were collected with 68 households in a small neighborhood; and, the author matched the NEMS-S scores to the store reported by households as their primary grocery store for regression tests. The results suggest that a tradeoff exists in the local food environment between food stores which negatively impact obesity risk for local residents. Exposure to this tradeoff appears to worsen as people live longer in the food desert. Thus, the results support the location of a food desert finding in Paraguay. The underlying factors of a food desert extend beyond food access to focus on the issues of justice. A way to improve upon future research to build scholarship on the relationship between deprivation and obesity requires that sample sizes are either large or representative of the population and that the research should be based on multiple neighborhood and city sites. Copyright © 2012 Wiley Periodicals, Inc.

Rates and characteristics of sleep paralysis in the general population of Denmark and Egypt.

PubMed

Jalal, Baland; Hinton, Devon E

2013-09-01

In the current research we report data from two studies that examined rates and characteristics of sleep paralysis (SP) in the general population of Denmark and Egypt. In Study I, individuals from Denmark and Egypt did not differ in age whereas there were more males in the Egyptian sample (47 vs. 64 %); in Study II, individuals from Denmark and Egypt were comparable in terms of age and gender distribution. In Study I we found that significantly fewer individuals had experienced SP in Denmark [25 % (56/223)] than in Egypt [44 % (207/470)] p < .001. In Study II we found that individuals who had experienced at least one lifetime episode of SP from Denmark (n = 58) as compared to those from Egypt (n = 143) reported significantly fewer SP episodes in a lifetime relative to SP experiencers from Egypt (M = 6.0 vs. M = 19.4, p < .001). SP in the Egyptian sample was characterized by high rates of SP (as compared to in Denmark), frequent occurrences (three times that in the Denmark sample), prolonged immobility during SP, and great fear of dying from the experience. In addition, in Egypt, believing SP to be precipitated by the supernatural was associated with fear of the experience and longer SP immobility. Findings are discussed in the context of cultural elaboration and salience theories of SP.

Diversity and Community Composition of Vertebrates in Desert River Habitats

PubMed Central

Free, C. L.; Baxter, G. S.; Dickman, C. R.; Lisle, A.; Leung, L. K.-P.

2015-01-01

Animal species are seldom distributed evenly at either local or larger spatial scales, and instead tend to aggregate in sites that meet their resource requirements and maximise fitness. This tendency is likely to be especially marked in arid regions where species could be expected to concentrate at resource-rich oases. In this study, we first test the hypothesis that productive riparian sites in arid Australia support higher vertebrate diversity than other desert habitats, and then elucidate the habitats selected by different species. We addressed the first aim by examining the diversity and composition of vertebrate assemblages inhabiting the Field River and adjacent sand dunes in the Simpson Desert, western Queensland, over a period of two and a half years. The second aim was addressed by examining species composition in riparian and sand dune habitats in dry and wet years. Vertebrate species richness was estimated to be highest (54 species) in the riverine habitats and lowest on the surrounding dune habitats (45 species). The riverine habitats had different species pools compared to the dune habitats. Several species, including the agamid Gowidon longirostris and tree frog Litoria rubella, inhabited the riverine habitats exclusively, while others such as the skinks Ctenotus ariadnae and C. dux were captured only in the dune habitats. The results suggest that, on a local scale, diversity is higher along riparian corridors and that riparian woodland is important for tree-dependent species. Further, the distribution of some species, such as Mus musculus, may be governed by environmental variables (e.g. soil moisture) associated with riparian corridors that are not available in the surrounding desert environment. We conclude that inland river systems may be often of high conservation value, and that management should be initiated where possible to alleviate threats to their continued functioning. PMID:26637127

Regional geothermal exploration in Egypt

NASA Technical Reports Server (NTRS)

Morgan, P.; Boulos, F. K.; Swanberg, C. A.

1983-01-01

A study is presented of the evaluation of the potential geothermal resources of Egypt using a thermal gradient/heat flow technique and a groundwater temperature/chemistry technique. Existing oil well bottom-hole temperature data, as well as subsurface temperature measurements in existing boreholes, were employed for the thermal gradient/heat flow investigation before special thermal gradient holes were drilled. The geographic range of the direct subsurface thermal measurements was extended by employing groundwater temperature and chemistry data. Results show the presence of a regional thermal high along the eastern margin of Egypt with a local thermal anomaly in this zone. It is suggested that the sandstones of the Nubian Formation may be a suitable reservoir for geothermal fluids. These findings indicate that temperatures of 150 C or higher may be found in this reservoir in the Gulf of Suez and Red Sea coastal zones where it lies at a depth of 4 km and deeper.

Regional changes and global connections: monitoring climate variability and change in the western United States

Treesearch

Henry F. Diaz

2004-01-01

Mountain ecosystems of the Western United States are complex and include cold desert biomes, such as those found in Nevada; subpolar biomes found in the upper treeline zone; and tundra ecosystems, occurring above timberline. Many studies (for example, Thompson 2000) suggest that high-elevation environments, comprising glaciers, snow, permafrost, water, and the...

Off-Road and the Fragile Desert

ERIC Educational Resources Information Center

Stebbins, Robert C.

1974-01-01

Part one of a two-part article sets forth the dimensions and the political-cultural aspects of the use of off-road vehicles in desert areas. Presents arguments for and against off-road vehicle use on national-resource land as exemplified in the California Desert. (Editor/JR)

The northern lakes of Egypt: Encounters with a wetland environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parmenter, B.M.

1991-01-01

Five lakes fringe the northern coast of Egypt. Together they represent 25% of the remaining wetland habitat in the Mediterranean basin. Residents of these lakes traditionally exploited a wide variety of resources. Today these lakes face a number of threats to their existence, including large-scale reclamation and water pollution. Agricultural authorities, engineers, fishery managers, and conservationists in Egypt and abroad debate about how best to manage and develop the lake region's resources, but few of these groups understand or communicate with one another, or with residents of lake communities. This study explores how these various groups encounter the coastal lakesmore » of Egypt, focusing particularly on Lakes Manzala and Burullus. Its purpose is to explore the ways in which the lakes, their resources and their inhabitants have been evaluated, and to analyze how underlying preconceptions, goals and structures of professional discourse influence such evaluations. The thesis is that environmental management is in reality not a rational plan but a process. Egypt is currently attempting to develop a coherent strategy to remedy its environmental problems without adversely affecting economic growth.« less

Desert Experimental Range: Annotated bibliography

Treesearch

E. Durant McArthur; Stanley G. Kitchen

2013-01-01

Entries qualify for inclusion if they were conducted in whole or part at the Desert Experimental Range (DER, also known as the Desert Range Experiment Station) or were based on DER research in whole or part. They do not qualify merely by the author having worked at the DER when the research was performed or prepared. Entries were drawn from the original abstracts or...

Remote Sensing Field Guide - Desert

DTIC Science & Technology

1991-09-01

rcatching on fire. Caution is advised against thorns on acacia trees, spikey Spinifex n•shes, and several different types of venomous snakes, as well as...e.g., mesquite, many acacias, Spinifex . DESERT PROCESSES WORKING GROUP PATTERN INDICATOR SHFET - DESERT DUNES PHOTOS: GROUND VEGETATION MOUNDS LOCATION...deliberate burning of natural vegetation is done episodically by the abo- rginal inhabitants. They burn the mature vegetation (primarily Spinifex ), which is

Fungal diversity in the Atacama Desert.

PubMed

Santiago, Iara F; Gonçalves, Vívian N; Gómez-Silva, Benito; Galetovic, Alexandra; Rosa, Luiz H

2018-03-07

Fungi are generally easily dispersed, able to colonise a wide variety of substrata and can tolerate diverse environmental conditions. However, despite these abilities, the diversity of fungi in the Atacama Desert is practically unknown. Most of the resident fungi in desert regions are ubiquitous. Some of them, however, seem to display specific adaptations that enable them to survive under the variety of extreme conditions of these regions, such as high temperature, low availability of water, osmotic stress, desiccation, low availability of nutrients, and exposure to high levels of UV radiation. For these reasons, fungal communities living in the Atacama Desert represent an unknown part of global fungal diversity and, consequently, may be source of new species that could be potential sources for new biotechnological products. In this review, we focus on the current knowledge of the diversity, ecology, adaptive strategies, and biotechnological potential of the fungi reported in the different ecosystems of the Atacama Desert.

Nationwide desert highway assessment: a case study in China.

PubMed

Mao, Xuesong; Wang, Fuchun; Wang, Binggang

2011-07-01

The natural environment affects the construction of desert highways. Conversely, highway construction affects the natural environment and puts the ecological environment at a disadvantage. To satisfy the variety and hierarchy of desert highway construction and discover the spatio-temporal distribution of the natural environment and its effect on highway construction engineering, an assessment of the natural regional divisions of desert highways in China is carried out for the first time. Based on the general principles and method for the natural region division, the principles, method and index system for desert highway assessment is put forward by combining the desert highway construction features and the azonal differentiation law. The index system combines the dominant indicator and four auxiliary indicators. The dominant indicator is defined by the desert's comprehensive state index and the auxiliary indicators include the sand dune height, the blown sand strength, the vegetation coverage ratio and the annual average temperature difference. First the region is divided according to the dominant indicator. Then the region boundaries are amended according to the four auxiliary indicators. Finally the natural region division map for desert highway assessment is presented. The Chinese desert highways can be divided into three sections: the east medium effect region, the middle medium-severe effect region, and the west slight-medium effect region. The natural region division map effectively paves the way for the route planning, design, construction, maintenance and ongoing management of desert highways, and further helps environmental protection.

Food deserts in Korea? A GIS analysis of food consumption patterns at sub-district level in Seoul using the KNHANES 2008-2012 data

PubMed Central

Kim, Dohyeong; Seo, Dong Yeon

2016-01-01

BACKGROUND/OBJECTIVES The concept of "food deserts" has been widely used in Western countries as a framework to identify areas with constrained access to fresh and nutritious foods, providing guidelines for targeted nutrition and public health programs. Unlike the vast amount of literature on food deserts in a Western context, only a few studies have addressed the concept in an East Asian context, and none of them have investigated spatial patterns of unhealthy food consumption from a South Korean perspective. SUBJECTS/METHODS We first evaluated the applicability of food deserts in a Korean setting and identified four Korean-specific unhealthy food consumption indicators, including insufficient food consumption due to financial difficulty, limited consumption of fruits and vegetables, excessive consumption of junk food, and excessive consumption of instant noodles. The KNHANES 2008-2012 data in Seoul were analyzed with stratified sampling weights to understand the trends and basic characteristics of these eating patterns in each category. GIS analyses were then conducted for the data spatially aggregated at the sub-district level in order to create maps identifying areas of concern regarding each of these indicators and their combinations. RESULTS Despite significant reduction in the rate of food insufficiency due to financial difficulty, the rates of excessive consumption of unhealthy foods (junk food and instant noodles) as well as limited consumption of fruits and vegetables have increased or remained high. These patterns tend to be found among relatively younger and more educated groups, regardless of income status. CONCLUSIONS A GIS-based analysis demonstrated several hotspots as potential "food deserts" tailored to the Korean context based on the observed spatial patterns of undesirable food consumption. These findings could be used as a guide to prioritize areas for targeted intervention programs to facilitate healthy food consumption behaviors and thus

Food deserts in Korea? A GIS analysis of food consumption patterns at sub-district level in Seoul using the KNHANES 2008-2012 data.

PubMed

Kim, Dohyeong; Lee, Chang Kil; Seo, Dong Yeon

2016-10-01

The concept of "food deserts" has been widely used in Western countries as a framework to identify areas with constrained access to fresh and nutritious foods, providing guidelines for targeted nutrition and public health programs. Unlike the vast amount of literature on food deserts in a Western context, only a few studies have addressed the concept in an East Asian context, and none of them have investigated spatial patterns of unhealthy food consumption from a South Korean perspective. We first evaluated the applicability of food deserts in a Korean setting and identified four Korean-specific unhealthy food consumption indicators, including insufficient food consumption due to financial difficulty, limited consumption of fruits and vegetables, excessive consumption of junk food, and excessive consumption of instant noodles. The KNHANES 2008-2012 data in Seoul were analyzed with stratified sampling weights to understand the trends and basic characteristics of these eating patterns in each category. GIS analyses were then conducted for the data spatially aggregated at the sub-district level in order to create maps identifying areas of concern regarding each of these indicators and their combinations. Despite significant reduction in the rate of food insufficiency due to financial difficulty, the rates of excessive consumption of unhealthy foods (junk food and instant noodles) as well as limited consumption of fruits and vegetables have increased or remained high. These patterns tend to be found among relatively younger and more educated groups, regardless of income status. A GIS-based analysis demonstrated several hotspots as potential "food deserts" tailored to the Korean context based on the observed spatial patterns of undesirable food consumption. These findings could be used as a guide to prioritize areas for targeted intervention programs to facilitate healthy food consumption behaviors and thus improve nutrition and food-related health outcomes.

Negotiating Sustainability: Reclaiming Ecological Pathways to Bio-Cultural Regeneration in Egypt

ERIC Educational Resources Information Center

Salem, Abeer Abdel Hamid

2013-01-01

What can an indigenous Egyptian paradigm for social evolution that represents the composite of bio-cultural diversities of Egypt and multiple bio-regions within it look like? With such exploratory inquiry in mind, this dissertation research focuses on analyzing the practice of development in Egypt through the lens of place, critiquing its…

Characterization of Morphology, Volatile Profiles, and Molecular Markers in Edible Desert Truffles from the Negev Desert.

PubMed

Kamle, Madhu; Bar, Einat; Lewinsohn, Dalia; Shavit, Elinoar; Roth-Bejerano, Nurit; Kagan-Zur, Varda; Barak, Ze'ev; Guy, Ofer; Zaady, Eli; Lewinsohn, Efraim; Sitrit, Yaron

2017-03-28

Desert truffles are mycorrhizal, hypogeous fungi considered a delicacy. On the basis of morphological characters, we identified three desert truffle species that grow in the same habitat in the Negev desert. These include Picoa lefebvrei (Pat.), Tirmania nivea (Desf.) Trappe, and Terfezia boudieri (Chatain), all associated with Helianthemum sessiliflorum. Their taxonomy was confirmed by PCR-RFLP. The main volatiles of fruit bodies of T. boudieri and T. nivea were 1-octen-3-ol and hexanal; however, volatiles of the latter species further included branched-chain amino acid derivatives such as 2-methylbutanal and 3-methylbutanal, phenylalanine derivatives such as benzaldehyde and benzenacetaldehyde, and methionine derivatives such as methional and dimethyl disulfide. The least aromatic truffle, P. lefebvrei, contained low levels of 1-octen-3-ol as the main volatile. Axenic mycelia cultures of T. boudieri displayed a simpler volatile profile compared to its fruit bodies. This work highlights differences in the volatile profiles of desert truffles and could hence be of interest for selecting and cultivating genotypes with the most likable aroma.

Nile River, Lake Nasser, Aswan High Dam, Egypt, Africa

NASA Technical Reports Server (NTRS)

1992-01-01

Lake Nasser, (24.0N, 33.0E) at the Aswan High Dam on the Nile River, in Egypt is the world's second largest artificial lake, extending 500 km, in length and about 5000 sq. km. in area. The lake has a storage capacity sufficient to irrigate farms in Egypt and Sudan year round allowing up to three harvests per year. Other benefits include year round river navagation, hydroelectric power, more fish harvests, reduced flooding and more industrial employment. opportunites.

Capital projects: Egypt case study. Technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lieberson, J.; Stallard, J.

1994-03-01

This report assesses the US Agency for International Development`s (A.I.D.`s) capital assistance program in Egypt in terms of both its commercial benefits for the United States and its developmental benefits for Egypt. In regard to the first aspect, the study found that few A.I.D.-funded projects or studies generated either participation by other donors or follow-on sales for U.S. companies. The report places much of the blame for this on U.S. firms` failure to take advantage of a clear opportunity to develop the Egyptian commercial market. Findings regarding the developmental benefits of the projects are mixed. (1) The projects helped supportmore » strong private sector growth in Egypt through the 1980`s. Nonetheless, their economic and financial rates of return were generally disappointing. (2) The projects were built to a high technical standard, but their sustainability is in doubt. (3) The pursuit of commercial advantage for U.S. firms did not distort the developmental goals of the projects. Overall, the report attributes the disappointing economic results of A.I.D.`s capital assistance program to a poor policy environment, which the reforms pursued in connection with the program did little to change.« less

Access to Higher Education in Egypt: Examining Trends by University Sector

ERIC Educational Resources Information Center

Buckner, Elizabeth

2013-01-01

Access to higher education in Egypt is expanding in both the public and private sectors. Using a nationally representative sample from the Survey of Young People in Egypt, this article is able to disaggregate patterns of access by both demographic group and university sector. Findings suggest that access in the public sector is governed strongly…

Climate Change Impacts, Vulnerabilities and Adaption Measures for Egypt's Nile Delta

NASA Astrophysics Data System (ADS)

Abutaleb, Khaled Abubakr Ali; Mohammed, Asmaa Hassan El-Sayed; Ahmed, Mahmoud H. Mohamed

2018-04-01

During the last few decades there has been growing concern about the impacts of climate change. A significant number of institutions, research centers, universities and governments have funded projects in addition to work done by independent scholars and assessors studying this phenomenon, in particular, to identify vulnerability, mitigation and adaptation against associated risks. Egypt is among the international community which took part in numerous studies, research activities, conferences, seminars and meetings attempting to address climate change and its associated risks. Egypt is particularly concerned with the threat to the Nile Delta as it is considered a low-lying land at high risk. The aim of this paper is to review current and previous projects, technical reports and pilot studies, concerning risk assessments, mitigation, and adaptation strategies for climate change in Egypt. This, in turn, will aid in decision making regarding future funding and establishing of research related to climate change in Egypt. This paper will also highlight the weaknesses and strengths of policymakers solely relying on one or more of these studies.

"Nile River Delta, Cairo and the Pyramids taken from Atlantis during STS-106"

NASA Image and Video Library

2000-09-09

STS106-701-025 (8-20 September 2000) --- One of the STS-106 crew members on board the Space Shuttle Atlantis used a handheld 70mm camera to photograph this image of Cairo, Egypt, the largest city in Africa. Its population is nearly 16 million, a figure which translates to approximately 130,000 people per square mile. Metropolitan Cairo shows as a gray area in the green of the Nile River valley at the apex of the Delta. The shadows of the three major pyramids at Giza on the Western edge of the city are visible. They are right below the bright new road construction. This side of the metropolitan area is experiencing rapid growth. According to geologists who have been studying shuttle-to-Earth imagery for many years, this photograph documents some of the many changes in land use in the Western Desert.

Colonial legacy, women's rights and gender-educational inequality in the Arab World with particular reference to Egypt and Tunisia

NASA Astrophysics Data System (ADS)

Megahed, Nagwa; Lack, Stephen

2011-08-01

One aspect of the call for democracy in the recent Arab region uprisings is the issue of women's rights and gender equality. Three cultural and ideological forces have continued to shape the gender discourse in Arab Muslim-majority societies. They are: "Islamic" teaching and local traditions concerning women's roles in a given society; Western, European colonial perception of women's rights; and finally national gender-related policy reforms. This paper examines the past and present status of women and gender-educational inequality in the Arab world with particular reference to Egypt and Tunisia, prior to and post colonialism. Special attention is given to colonial legacy and its influence on gender and education; to current gender practices in the social sphere with a focus on women's modesty ( hijab); to international policies and national responses with regard to women's rights and finally to female participation in pre-university and higher education. These issues incorporate a discussion of cultural and religious constraints. The paper demonstrates similarities and differences between Egypt's and Tunisia's reform policies towards gender parity. It highlights the confrontation of conservative versus liberal ideologies that occurred in each country with the implementation of its gender-related reform policy.

Deriving Polarization Properties of Desert-Reflected Solar Spectra with PARASOL Data

NASA Technical Reports Server (NTRS)

Sun, Wenbo; Baize, Rosemary R.; Lukashin, Constantine

2015-01-01

Reflected solar radiation from desert is strongly polarized by sand particles. To date, there is no reliable desert surface reflection model to calculate desert reflection matrix. In this study, the PARASOL data are used to retrieve physical properties of desert. These physical properties are then used in the ADRTM to calculate polarization of desert-reflected light for the whole solar spectra.

African refugees in Egypt: trauma, loss, and cultural adjustment.

PubMed

Henry, Hani M

2012-08-01

This study examined the influence of pre-immigration trauma on the acculturation process of refugees, as reflected in the manifestations of their continuing bonds with native cultures. Six African refugees who sought refuge in Egypt because of wars and political persecution were interviewed about the circumstances of their departure from their home countries, as well as their life experiences in Egypt. All participants kept continuing bonds with their native cultures, but these bonds manifested differently depending on their ability to assimilate pre-immigration trauma and cultural losses. Participants who successfully assimilated both pre-immigration trauma and cultural losses developed continuing bonds with their native cultures that helped them (a) integrate the Egyptian culture into their life experiences and (b) tolerate difficult political conditions in Egypt. Participants who could not assimilate their pre-immigration trauma and cultural losses also developed continuing bonds with their native culture, but these bonds only provided them with solace.

Improved highway design methods for desert storms

DOT National Transportation Integrated Search

2007-08-01

This report provides identification of desert hydrologic regions within the arid and semi-arid portions of California, as well as information and direction in choosing appropriate hydrologic and bulking methods specific to each identified desert regi...

X-36 in Flight over Mojave Desert

NASA Image and Video Library

1997-10-30

The unusual lines of the X-36 technology demonstrator contrast sharply with the desert floor as the remotely piloted aircraft scoots across the California desert at low altitude during a research flight on October 30, 1997.

76 FR 50493 - Notice of Availability of the Record of Decision for the Desert Sunlight Holdings, LLC, Desert...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-15

... a solar photovoltaic (PV) facility, capable of producing 550 MW of electrical output. Southern... Sunlight Solar Farm (DSSF) and California Desert Conservation Area Plan Amendment, California AGENCY... . SUPPLEMENTARY INFORMATION: Desert Sunlight Holdings, LLC, a wholly owned subsidiary of First Solar, Inc., filed...

School Psychology in Egypt: Results of the 2008 International School Psychology Survey

ERIC Educational Resources Information Center

Jimerson, Shane R.; Alghorani, Mohammad Adnan; Darweish, Abdel-Hameed; Abdelaziz, Mahmoud

2010-01-01

The International School Psychology Survey (ISPS) was used to gather information about the characteristics, training, roles, activities, preferences, research interests and the challenges experienced by school psychology specialists in Egypt. To the degree that the data are representative of the school psychology specialists Egypt, it appears that…

The Riparianness of a Desert Herpetofauna

Treesearch

Charles H. Lowe

1989-01-01

Within the Mojave, Sonoran, and Chihuahuan Desert subdivisions of the North American Desert in the U.S., more than half of 143 total amphibian and reptilian species perform as riparian and/or wetland taxa. For the reptiles, but not the amphibians, there is a significant inverse relationship between riparianness (obligate through preferential and facultative to...

Gopherus agassizii (desert tortoise). Burrow collapse

USGS Publications Warehouse

Loughran, Caleb L.; Ennen, Joshua; Lovich, Jeffrey E.

2011-01-01

In the deserts of the southwestern U.S., burrows are utilized by the Desert Tortoise to escape environmental extremes (reviewed by Ernst and Lovich 2009. Turtles of the United States and Canada. 2nd ed. Johns Hopkins Univ. Press, Baltimore, Maryland. 827 pp.). However, the potential for mortality through burrow collapse and entrapment is poorly documented. Nicholson and Humphreys (1981. Proceedings of the Desert Tortoise Council, pp. 163−194) suggested that collapse due to livestock trampling may cause mortality. In addition, Lovich et al. (2011. Chelon. Cons. Biol. 10[1]:124–129) documented a Desert Tortoise that used a steel culvert as a burrow surrogate. The culvert filled completely with sediment following a significant rain event, entombing the animal and ultimately resulting in its death. We note that this mortality was associated with an anthropogenic structure; because tortoises are prodigious diggers, one might hypothesize that they have the ability to dig out of collapsed natural burrows in most situations. Circumstances described here presented us with an opportunity to test this hypothesis.

Microbial ecology of hot desert edaphic systems.

PubMed

Makhalanyane, Thulani P; Valverde, Angel; Gunnigle, Eoin; Frossard, Aline; Ramond, Jean-Baptiste; Cowan, Don A

2015-03-01

A significant proportion of the Earth's surface is desert or in the process of desertification. The extreme environmental conditions that characterize these areas result in a surface that is essentially barren, with a limited range of higher plants and animals. Microbial communities are probably the dominant drivers of these systems, mediating key ecosystem processes. In this review, we examine the microbial communities of hot desert terrestrial biotopes (including soils, cryptic and refuge niches and plant-root-associated microbes) and the processes that govern their assembly. We also assess the possible effects of global climate change on hot desert microbial communities and the resulting feedback mechanisms. We conclude by discussing current gaps in our understanding of the microbiology of hot deserts and suggest fruitful avenues for future research. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Lidar Measurements for Desert Dust Characterization: An Overview

NASA Technical Reports Server (NTRS)

Mona, L.; Liu, Z.; Mueller, D.; Omar, A.; Papayannis, A.; Pappalardo, G.; Sugimoto, N.; Vaughan, M.

2012-01-01

We provide an overview of light detection and ranging (lidar) capability for describing and characterizing desert dust. This paper summarizes lidar techniques, observations, and fallouts of desert dust lidar measurements. The main objective is to provide the scientific community, including non-practitioners of lidar observations with a reference paper on dust lidar measurements. In particular, it will fill the current gap of communication between research-oriented lidar community and potential desert dust data users, such as air quality monitoring agencies and aviation advisory centers. The current capability of the different lidar techniques for the characterization of aerosol in general and desert dust in particular is presented. Technical aspects and required assumptions of these techniques are discussed, providing readers with the pros and cons of each technique. Information about desert dust collected up to date using lidar techniques is reviewed. Lidar techniques for aerosol characterization have a maturity level appropriate for addressing air quality and transportation issues, as demonstrated by some first results reported in this paper

Electricity end use demand study for Egypt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turiel, I.; Lebot, B.; Nadel, S.

1990-12-01

This report describes the results of a study undertaken by Lawrence Berkeley Laboratory (LBL) to develop an approach for reducing electricity demand in the residential sector in Egypt. A team with expertise in appliance energy usage, appliance manufacturing, appliance testing, and energy analysis was assembled to work on this project. The team visited Egypt during the month of March 1990. They met with the Egyptian Organization for Energy Planning (OEP) and with many other parties. They also visited eleven appliance manufacturing facilities. The project tasks are: data gathering and analysis; assessment of appliance manufacturing plants; demonstration of microcomputer programs; gatheringmore » of data on appliance standards and test procedures; and impact of programs to foster energy efficiency of electricity use.« less

Nationwide Desert Highway Assessment: A Case Study in China

PubMed Central

Mao, Xuesong; Wang, Fuchun; Wang, Binggang

2011-01-01

The natural environment affects the construction of desert highways. Conversely, highway construction affects the natural environment and puts the ecological environment at a disadvantage. To satisfy the variety and hierarchy of desert highway construction and discover the spatio-temporal distribution of the natural environment and its effect on highway construction engineering, an assessment of the natural regional divisions of desert highways in China is carried out for the first time. Based on the general principles and method for the natural region division, the principles, method and index system for desert highway assessment is put forward by combining the desert highway construction features and the azonal differentiation law. The index system combines the dominant indicator and four auxiliary indicators. The dominant indicator is defined by the desert’s comprehensive state index and the auxiliary indicators include the sand dune height, the blown sand strength, the vegetation coverage ratio and the annual average temperature difference. First the region is divided according to the dominant indicator. Then the region boundaries are amended according to the four auxiliary indicators. Finally the natural region division map for desert highway assessment is presented. The Chinese desert highways can be divided into three sections: the east medium effect region, the middle medium-severe effect region, and the west slight-medium effect region. The natural region division map effectively paves the way for the route planning, design, construction, maintenance and ongoing management of desert highways, and further helps environmental protection. PMID:21845155

A mathematical model on the optimal timing of offspring desertion.

PubMed

Seno, Hiromi; Endo, Hiromi

2007-06-07

We consider the offspring desertion as the optimal strategy for the deserter parent, analyzing a mathematical model for its expected reproductive success. It is shown that the optimality of the offspring desertion significantly depends on the offsprings' birth timing in the mating season, and on the other ecological parameters characterizing the innate nature of considered animals. Especially, the desertion is less likely to occur for the offsprings born in the later period of mating season. It is also implied that the offspring desertion after a partially biparental care would be observable only with a specific condition.

Isotopic Evidence for Early Trade in Animals between Old Kingdom Egypt and Canaan.

PubMed

Arnold, Elizabeth R; Hartman, Gideon; Greenfield, Haskel J; Shai, Itzhaq; Babcock, Lindsay E; Maeir, Aren M

2016-01-01

Isotope data from a sacrificial ass and several ovicaprines (sheep/goat) from Early Bronze Age household deposits at Tell es-Safi/Gath, Israel provide direct evidence for the movement of domestic draught/draft and husbandry animals between Old Kingdom Egypt (during the time of the Pyramids) and Early Bronze Age III Canaan (ca. 2900-2500 BCE). Vacillating, bi-directional connections between Egypt and Canaan are known throughout the Early Bronze Age, but here we provide the first concrete evidence of early trade in animals from Egypt to Canaan.

Isotopic Evidence for Early Trade in Animals between Old Kingdom Egypt and Canaan

PubMed Central

Greenfield, Haskel J.; Shai, Itzhaq; Babcock, Lindsay E.; Maeir, Aren M.

2016-01-01

Isotope data from a sacrificial ass and several ovicaprines (sheep/goat) from Early Bronze Age household deposits at Tell es-Safi/Gath, Israel provide direct evidence for the movement of domestic draught/draft and husbandry animals between Old Kingdom Egypt (during the time of the Pyramids) and Early Bronze Age III Canaan (ca. 2900–2500 BCE). Vacillating, bi-directional connections between Egypt and Canaan are known throughout the Early Bronze Age, but here we provide the first concrete evidence of early trade in animals from Egypt to Canaan. PMID:27322197

Ultraviolet radiation in the Atacama Desert.

PubMed

Cordero, R R; Damiani, A; Jorquera, J; Sepúlveda, E; Caballero, M; Fernandez, S; Feron, S; Llanillo, P J; Carrasco, J; Laroze, D; Labbe, F

2018-03-31

The world's highest levels of surface ultraviolet (UV) irradiance have been measured in the Atacama Desert. This area is characterized by its high altitude, prevalent cloudless conditions, and a relatively low total ozone column. In this paper, we provide estimates of the surface UV (monthly UV index at noon and annual doses of UV-B and UV-A) for all sky conditions in the Atacama Desert. We found that the UV index at noon during the austral summer is expected to be greater than 11 in the whole desert. The annual UV-B (UV-A) doses were found to range from about 3.5 kWh/m 2 (130 kWh/m 2 ) in coastal areas to 5 kWh/m 2 (160 kWh/m 2 ) on the Andean plateau. Our results confirm significant interhemispherical differences. Typical annual UV-B doses in the Atacama Desert are about 40% greater than typical annual UV-B doses in northern Africa. Mostly due to seasonal changes in the ozone, the differences between the Atacama Desert and northern Africa are expected to be about 60% in the case of peak UV-B levels (i.e. the UV-B irradiances at noon close to the summer solstice in each hemisphere). Interhemispherical differences in the UV-A are significantly lower since the effect of the ozone in this part of the spectrum is minor.

Observational Evidence for Desert Amplification Using Multiple Satellite Datasets.

PubMed

Wei, Nan; Zhou, Liming; Dai, Yongjiu; Xia, Geng; Hua, Wenjian

2017-05-17

Desert amplification identified in recent studies has large uncertainties due to data paucity over remote deserts. Here we present observational evidence using multiple satellite-derived datasets that desert amplification is a real large-scale pattern of warming mode in near surface and low-tropospheric temperatures. Trend analyses of three long-term temperature products consistently confirm that near-surface warming is generally strongest over the driest climate regions and this spatial pattern of warming maximizes near the surface, gradually decays with height, and disappears in the upper troposphere. Short-term anomaly analyses show a strong spatial and temporal coupling of changes in temperatures, water vapor and downward longwave radiation (DLR), indicating that the large increase in DLR drives primarily near surface warming and is tightly associated with increasing water vapor over deserts. Atmospheric soundings of temperature and water vapor anomalies support the results of the long-term temperature trend analysis and suggest that desert amplification is due to comparable warming and moistening effects of the troposphere. Likely, desert amplification results from the strongest water vapor feedbacks near the surface over the driest deserts, where the air is very sensitive to changes in water vapor and thus efficient in enhancing the longwave greenhouse effect in a warming climate.

Adaptive responses reveal contemporary and future ecotypes in a desert shrub

USGS Publications Warehouse

Richardson, Bryce A.; Kitchen, Stanley G.; Pendleton, Rosemary L.; Pendleton, Burton K.; Germino, Matthew J.; Rehfeldt, Gerald E.; Meyer, Susan E.

2014-01-01

Interacting threats to ecosystem function, including climate change, wildfire, and invasive species necessitate native plant restoration in desert ecosystems. However, native plant restoration efforts often remain unguided by ecological genetic information. Given that many ecosystems are in flux from climate change, restoration plans need to account for both contemporary and future climates when choosing seed sources. In this study we analyze vegetative responses, including mortality, growth, and carbon isotope ratios in two blackbrush (Coleogyne ramosissima) common gardens that included 26 populations from a range-wide collection. This shrub occupies ecotones between the warm and cold deserts of Mojave and Colorado Plateau ecoregions in western North America. The variation observed in the vegetative responses of blackbrush populations was principally explained by grouping populations by ecoregions and by regression with site-specific climate variables. Aridity weighted by winter minimum temperatures best explained vegetative responses; Colorado Plateau sites were usually colder and drier than Mojave sites. The relationship between climate and vegetative response was mapped within the boundaries of the species–climate space projected for the contemporary climate and for the decade surrounding 2060. The mapped ecological genetic pattern showed that genetic variation could be classified into cool-adapted and warm-adapted ecotypes, with populations often separated by steep clines. These transitions are predicted to occur in both the Mojave Desert and Colorado Plateau ecoregions. While under contemporary conditions the warm-adapted ecotype occupies the majority of climate space, climate projections predict that the cool-adapted ecotype could prevail as the dominant ecotype as the climate space of blackbrush expands into higher elevations and latitudes. This study provides the framework for delineating climate change-responsive seed transfer guidelines, which are

Granivory and microhabitat use in Australian desert rodents: are seeds important?

PubMed

Murray, Brad R; Dickman, Chris R

1994-09-01

The diet and microhabitat use of two species of native Australian desert rodents, the spinifex hoppingmouseNotomys alexis and sandy inland mousePseudomys hermannsburgensis, were studied in the Simpson Desert, south-western Queensland. Contrary to expectation, both species were confirmed from analyses of their stomach contents to be omnivorous. The diets of both species varied through time in a similar manner; seeds were important in summer and especially in winter, but in autumn invertebrates constituted nearly 50% and 60% of the diet ofN. alexis andP. hermannsburgensis, respectively. Other plant material (root, leaf, floral part, stem) was found in appreciable amounts in the stomach contents of both species, and fungi were identified from a small number of individuals. Both species showed a high degree of overlap in the broad types of food they ingested (seed, plant material, invertebrates); however, there was considerably less overlap in the species of seeds eaten. Analysis of microhabitat use suggested that this difference was due to differential foraging between the species; the larger, bipedalN. alexis forages in the open more than the smaller, quadrupedalP. hermannsburgensis, which is found more commonly in or under hummocks of spinifex grass. Although our findings parallel patterns of morphological specialisation and differential foraging on seeds that have been described within communities of North American heteromyid rodents, we found little evidence that the foraging economics ofN. alexis orP. hermannsburgensis should depend solely or primarily on the distribution patterns of seeds. In the absence of dietary information, we suggest that ecological studies of desert rodents which focus solely on granivory, and neglect other important aspects of rodent foraging, can lead to a misinterpretation of species coexistence and community structure.

Adaptive responses reveal contemporary and future ecotypes in a desert shrub.

PubMed

Richardson, Bryce A; Kitchen, Stanley G; Pendleton, Rosemary L; Pendleton, Burton K; Germino, Matthew J; Rehfeldt, Gerald E; Meyer, Susan E

2014-03-01

Interacting threats to ecosystem function, including climate change, wildfire, and invasive species necessitate native plant restoration in desert ecosystems. However, native plant restoration efforts often remain unguided by ecological genetic information. Given that many ecosystems are in flux from climate change, restoration plans need to account for both contemporary and future climates when choosing seed sources. In this study we analyze vegetative responses, including mortality, growth, and carbon isotope ratios in two blackbrush (Coleogyne ramosissima) common gardens that included 26 populations from a range-wide collection. This shrub occupies ecotones between the warm and cold deserts of Mojave and Colorado Plateau ecoregions in western North America. The variation observed in the vegetative responses of blackbrush populations was principally explained by grouping populations by ecoregions and by regression with site-specific climate variables. Aridity weighted by winter minimum temperatures best explained vegetative responses; Colorado Plateau sites were usually colder and drier than Mojave sites. The relationship between climate and vegetative response was mapped within the boundaries of the species-climate space projected for the contemporary climate and for the decade surrounding 2060. The mapped ecological genetic pattern showed that genetic variation could be classified into cool-adapted and warm-adapted ecotypes, with populations often separated by steep dines. These transitions are predicted to occur in both the Mojave Desert and Colorado Plateau ecoregions. While under contemporary conditions the warm-adapted ecotype occupies the majority of climate space, climate projections predict that the cool-adapted ecotype could prevail as the dominant ecotype as the climate space of blackbrush expands into higher elevations and latitudes. This study provides the framework for delineating climate change-responsive seed transfer guidelines, which are needed

Modeling Habitat of the Desert Tortoise (Gopherus agassizii) in the Mojave and Parts of the Sonoran Deserts of California, Nevada, Utah, and Arizona

USGS Publications Warehouse

Nussear, Kenneth E.; Esque, Todd C.; Inman, Richard D.; Gass, Leila; Thomas, Kathryn A.; Wallace, Cynthia S.A.; Blainey, Joan B.; Miller, David M.; Webb, Robert H.

2009-01-01

Habitat modeling is an important tool used to simulate the potential distribution of a species for a variety of basic and applied questions. The desert tortoise (Gopherus agassizii) is a federally listed threatened species in the Mojave Desert and parts of the Sonoran Desert of California, Nevada, Utah, and Arizona. Land managers in this region require reliable information about the potential distribution of desert tortoise habitat to plan conservation efforts, guide monitoring activities, monitor changes in the amount and quality of habitat available, minimize and mitigate disturbances, and ultimately to assess the status of the tortoise and its habitat toward recovery of the species. By applying information from the literature and our knowledge or assumptions of environmental variables that could potentially explain variability in the quality of desert tortoise habitat, we developed a quantitative habitat model for the desert tortoise using an extensive set of field-collected presence data. Sixteen environmental data layers were converted into a grid covering the study area and merged with the desert tortoise presence data that we gathered for input into the Maxent habitat-modeling algorithm. This model provides output of the statistical probability of habitat potential that can be used to map potential areas of desert tortoise habitat. This type of analysis, while robust in its predictions of habitat, does not account for anthropogenic changes that may have altered habitat with relatively high potential into areas with lower potential.

Ostrich (Struthio camelus) production in Egypt.

PubMed

Cooper, R G; Mahrose, K M A; El-Shafei, M; Marai, I F M

2008-06-01

This review discusses the historical, developmental and practices of ostrich farming in Egypt. In the early 20th century, ostrich farming was very important for production of ostrich feathers and documents were produced to perfect the art of procuring the plumes from the birds and subsequently processing them. Pharaohs used ostrich feathers for adornment. Of 43 provinces, 12 were featured in 2003-2004 as farming ostriches: Alexandria, Al-Behera, Al-Dakahlia, Al-Wadi Al-Gadid, Aswan, Cairo, El-Sharkia, Geiza, Ismailia, Kafr-El-Sheikh, Matrouh and Nubaria. Abattoirs and tanneries specialising in ostrich handling are limited to two. Egypt has numerous strengths and opportunities to develop its ostrich sector. Rising meat prices suggest that fresh ostrich meat is unaffordable to many locals. Funds may be allocated to local advertising campaigns to promote ostrich meat; provision of incentives to farmers; and improving the capacity of abattoirs.

Space Radar Image of Safsaf Oasis, Egypt

NASA Image and Video Library

1999-04-15

This three-frequency space radar image of south-central Egypt demonstrates the unique capability of imaging radar to penetrate thin sand cover in arid regions to reveal hidden details below the surface.

Identification of debris-flow hazards in warm deserts through analyzing past occurrences: Case study in South Mountain, Sonoran Desert, USA

NASA Astrophysics Data System (ADS)

Dorn, Ronald I.

2016-11-01

After recognition that debris flows co-occur with human activities, the next step in a hazards analysis involves estimating debris-flow probability. Prior research published in this journal in 2010 used varnish microlamination (VML) dating to determine a minimum occurrence of 5 flows per century over the last 8100 years in a small mountain range of South Mountain adjacent to neighborhoods of Phoenix, Arizona. This analysis led to the conclusion that debris flows originating in small mountain ranges in arid regions like the Sonoran Desert could pose a hazard. Two major precipitation events in the summer of 2014 generated 35 debris flows in the same study area of South Mountain-providing support for the importance of probability analysis as a key step in a hazards analysis in warm desert settings. Two distinct mechanisms generated the 2014 debris flows: intense precipitation on steep slopes in the first storm; and a firehose effect whereby runoff from the second storm was funneled rapidly by cleaned-out debris-flow chutes to remobilize Pleistocene debris-flow deposits. When compared to a global database on debris flows, the 2014 storms were among the most intense to generate desert debris flows - indicating that storms of lesser intensity are capable of generating debris flows in warm desert settings. The 87Sr/86Sr analyses of fines and clasts in South Mountain debris flows of different ages reveal that desert dust supplies the fines. Thus, wetter climatic periods of intense rock decay are not needed to resupply desert slopes with fines; instead, a combination of dust deposition supplying fines and dirt cracking generating coarse clasts can re-arm chutes in a warm desert setting with abundant dust.

An experimental analysis of granivory in desert ecosystems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Davidson, D.W.

1988-01-01

In our studies of desert granivore ecology, we have outlined the network of interaction pathways linking granivore and resource species in a Chihuahuan Desert Ecosystem. Here, a major fraction of the primary productivity takes the form of the seeds of annual plants. These seeds support two major resident taxa of desert granivores, ants and rodents. Population responses to removal of various taxa of granivores or seasonal classes of resource species are described.

Browning in Desert Boundaries in Asia in Recent Decades

NASA Technical Reports Server (NTRS)

Jeong, Su-Jong; Ho, Chang-Hoi; Brown, Molly E.; Kug, Jong-Seong; Piao, Shilong

2011-01-01

In this study, the changes in desert boundaries in Asia (Gobi, Karakum, Lut, Taklimakan, and Thar deserts) during the growing season (April October) in the years 1982 2008 were investigated by analyzing the normalized difference vegetation index (NDVI), precipitation, and temperature. In the desert boundary regions, the domain mean NDVI values increased by 7.2% per decade in 1982 1998 but decreased by 6.8% per decade thereafter. Accordingly, the bare soil areas (or nonvegetated areas) of the inside of the desert boundaries contracted by 9.8% per decade in the 1990s and expanded by 8.7% per decade in the 2000s. It is noted that the five deserts experience nearly simultaneous NDVI changes although they cover a very diverse area of Asia. In contrast, changes in temperature and precipitation in the deserts show rather diverse results. In desert boundaries located along 40 N (Gobi, Taklimakan, and Karakum), the decadal changes in vegetation greenness were mainly related to regional climate during the entire analysis period. Precipitation increased in the 1990s, providing favorable conditions for vegetation growth (i.e., greening), but precipitation reduced (19 mm per decade) and warming intensified (0.7 C per decade) in the 2000s, causing less moisture to be available for vegetation growth (i.e., browning). In desert boundaries below 40 N (Lut and Thar), although an increase in precipitation (8 mm per decade) led to greening in the 1990s, local changes in precipitation and temperature did not necessarily cause browning in the 2000s. Observed multidecadal changes in vegetation greenness in the present study suggest that under significant global and/or regional warming, changes in moisture availability for vegetation growth in desert boundaries are an important factor when understanding decadal changes in areas vulnerable to desertification over Asia.

Incidence and socioeconomic determinants of abortion in rural Upper Egypt.

PubMed

Yassin, K M

2000-07-01

Because of a growing cultural and religious sensitivity and controversy over reproductive health issues, particularly abortion, this area remains relatively unexplored in Egypt. This study was conducted using a participatory approach to determine the morbidity and determinants of abortion in rural Upper Egypt. In all, 1025 women from six villages in Upper Egypt were included in the study. Information regarding the incidence of abortion, patterns of health care utilization and risk factors was obtained using a structured interview format. The local dialect was used in formulating questions and they were revised and amended by a panel of local leaders, interviewers and representatives of the study population. Interviewers were local educated (secondary or university level) female volunteers. Information about exposure to 17 risk factors was also collected and statistical analysis was done by estimating the odds ratio and applying a test of statistical significance. Then, a multivariate logistic regression model was applied to control for possible interactions and confounding effects. The results were that 40.6% (n=416) had aborted at least once; of them 24.6% (n=252) had aborted more than once and were designated as recurrent aborters. The lifetime prevalence of recurrent abortion was estimated to be 25% and nearly 21% of pregnancies were aborted. The incidence of abortion was estimated to be 265 per 1000 live birth. Only 21.9% (n=91) of women received medical care for the last abortion. The vast majority of women (92%, n=299) who did not seek medical help received help from traditional and domestic sources. These sources are midwife (59.9%, n=179), relative or neighbour (29.8%, n=89), and traditional practitioner (10.4%, n=31). The multivariate analysis revealed that the incidence of abortion is significantly associated with gravidity, consanguinity, and mother occupation, while recurrent abortion is associated with gravidity, consanguinity and woman's age at

Paleo-oncology in the Dakhleh Oasis, Egypt: Case studies and a paleoepidemiological perspective.

PubMed

Molto, El; Sheldrick, Peter

2018-06-01

This article describes six cases of cancer from the Dakhleh Oasis, Egypt. A mummy had a confirmed 'primary' diagnosis of adenocarcinoma of the rectum. The remaining diagnoses were based on the distribution and types of skeletal lesions in conjunction with age, sex, and/or the molecular phylogeny of the Human Papillomavirus (HPV). HPV is a confirmed cause of cancer of the uterine cervix (UC) and testes (TC) and it evolved in Africa long before Homo sapiens emerged. Today these cancers are common in young adult females and males, a fact which was pivotal in respectively including them in the differential diagnosis of UC and TC. The remaining diagnoses were acute lymphocytic leukemia in a 3-5 year old child and an older female with metastatic carcinoma. Due to problems of determining specific diagnoses and their prevalence in 'paleo' populations, we opted for a lifetime cancer risk statistic (LTCR). The LTCR in ancient Dakhleh was ∼5/1000 (6/1087). In modern Western societies the LTCR cancer approaches 50% (500/1000). Thus the LTCR in today's western societies is 100 times greater than in ancient Dakhleh. These cases demonstrate that oncogenes and their environmental cofactors were present in antiquity, but were significantly less pervasive than today. Copyright © 2018. Published by Elsevier Inc.

Growth responses of five desert plants as influenced by biological soil crusts from a temperate desert, China

USGS Publications Warehouse

Zhang, Yuanming; Belnap, Jayne

2015-01-01

In almost all dryland systems, biological soil crusts (biocrusts) coexist alongside herbaceous and woody vegetation, creating landscape mosaics of vegetated and biocrusted patches. Results from past studies on the interaction between biocrusts and vascular plants have been contradictory. In the Gurbantunggut desert, a large temperate desert in northwestern China, well-developed lichen-dominated crusts dominate the areas at the base and between the sand dunes. We examined the influence of these lichen-dominated biocrusts on the germination, growth, biomass accumulation, and elemental content of five common plants in this desert: two shrubs (Haloxylon persicum, Ephedra distachya) and three herbaceous plants (Ceratocarpus arenarius, Malcolmia africana and Lappula semiglabra) under greenhouse conditions. The influence of biocrusts on seed germination was species-specific. Biocrusts did not affect percent germination in plants with smooth seeds, but inhibited germination of seeds with appendages that reduced or eliminated contact with the soil surface or prevented seeds from slipping into soil cracks. Once seeds had germinated, biocrusts had different influences on growth of shrub and herbaceous plants. The presence of biocrusts increased concentrations of nitrogen but did not affect phosphorus or potassium in tissue of all tested species, while the uptake of the other tested nutrients was species-specific. Our study showed that biocrusts can serve as a biological filter during seed germination and also can influence growth and elemental uptake. Therefore, they may be an important trigger for determining desert plant diversity and community composition in deserts.

76 FR 59682 - Desert Southwest Customer Service Region-Western Area Lower Colorado Balancing Authority-Rate...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-09-27

... percentage of metered generation, since there is no load. 2. Intermittent resources are exempt from the outer...--Western Area Lower Colorado Balancing Authority--Rate Order No. WAPA-151 AGENCY: Western Area Power... Services Formula Rates. SUMMARY: The Deputy Secretary of Energy has confirmed and approved Rate Order No...

Arab Republic of Egypt: An Economic Analysis of Early Childhood Education/Development.

ERIC Educational Resources Information Center

Janssens, Wendy; Van Der Gaag, Jacques; Tanaka, Shinichiro

Within Egypt's national framework for improving access to and quality of education, the government has announced the intention of enlarging compulsory basic education with 1 or 2 years of preschool. This report to the World Bank examines early childhood development (ECD) in Egypt from an economic and financial perspective. Following an executive…

Detection of Strawberry Viruses in Egypt

USDA-ARS?s Scientific Manuscript database

As part of a USAID-MERC funded project, ‘Disease-indexing and mass propagation of superior strawberry cultivars’, an effort was made to evaluate the virus status of strawberries in Egypt. Diagnostic reverse transcription-polymerase chain reaction (RT-PCR) tests for Strawberry mottle, Strawberry cri...

Studying and analyzing the formation and dynamics of the black cloud over Cairo, Egypt, using a multi sensor approach

NASA Astrophysics Data System (ADS)

El-Askary, H. M.; Prasad, A. K.; Marey, H. M.; El-Raey, M. E.; Asrar, G. R.; Kafatos, M.

2012-04-01

In the past decade, episodes of severe air pollution from biomass burning and/or industrial activities, known as the "black cloud" have occurred over Cairo, and the Nile Delta region situated on the eastern side of the Sahara desert in Egypt, during the autumn season. Previous studies have attributed the increased pollution levels during the black cloud season only to the biomass or open burning of agricultural waste, vehicular, industrial emissions, and secondary aerosols. However, new multi-sensor observations (column and vertical profiles) from satellites, dust transport models and associated meteorology present a different picture of the autumn pollution. It was found that the same region receives as well numerous dust storms along with the anthropogenic aerosols during same season. Such complex combination of these aerosols results in poor air quality and poses significant health hazards for the population in this region. In this study, data from the Moderate Resolution Imaging Spectrometer (MODIS) along with the Multiangle Imaging Spectroradiometer (MISR) are used with meteorological data and trajectory analyses to determine the cause of these events. MODIS fire counts highlighted the anthropogenic component of the dense cloud resulting from the burning of agricultural waste after harvest season. Synchronous MISR data show that these fires create low altitude (<500 m) plumes of smoke and aerosols which flow over Cairo in a few hours, as confirmed by Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) forward trajectory analysis. Much of the burning occurs at night, when a thermal inversion constrains the plumes to remain in the boundary layer (BL). Convection during the day raises the BL, dispersing these smoke particles until the next night. However, we have found a dust transport pathway along the Mauritania/Mali/Algeria/Libya/Egypt axis that significantly affects NE Africa, especially the Nile Delta region, during the biomass burning season

Eternal Egypt: Masterworks of Ancient Art from the British Museum. Learning from Exhibitions.

ERIC Educational Resources Information Center

Johnson, Mark M.

2001-01-01

Introduces the exhibition "Eternal Egypt: Masterworks of Ancient Art from the British Museum" that explores the four major periods of Egyptian history. Provides background information on ancient Egypt and describes the art that was present in each of the four kingdoms. (CMK)

Neurosurgery in Egypt: past, present, and future-from pyramids to radiosurgery.

PubMed

El Gindi, Sayed

2002-09-01

THE CONTEMPORARY DEVELOPMENT of neurosurgery in Egypt is described, with reference to the ancient past and recent American and European influences. This article traces the steps taken by several leading Egyptian pioneers. Egypt, one of the key countries in the Middle East, has led the development of the specialty in the region and has maintained close ties with the international body of neurological surgeons and surgical societies.

The Use of Water During the Crew 144, Mars Desert Research Station, Utah Desert

NASA Astrophysics Data System (ADS)

De Morais Mendonca Teles, Antonio

2016-07-01

Well. from November 29th to December 14th, 2014, the author conducted astrobiological and geological surveys, as analog astronaut member of the international Crew 144, at the site of the Mars Society's Mars Desert Research Station, located at a remote location in the Utah desert, United States. The use of water for drinking, bathing, cleaning, etc., in the crew was a major issue for consideration for a human expedition to the planet Mars in the future. The author would like to tell about the factors of the rationalized use of water.

iss031e148455

NASA Image and Video Library

2012-06-21

ISS031-E-148455 (21 June 2012) --- Toshka Lakes in southern Egypt are featured in this image photographed by an Expedition 31 crew member on the International Space Station. The Toshka Lakes (center) were formed in the Sahara Desert of Egypt by water from the River Nile conveyed from Lake Nasser by a canal to the Toshka Depression. Flooding of the Toshka Depression had created the four main lakes with a maximum surface area in 2002 of approximately 1,450 square kilometers ? around 25.26 billion cubic meters of water. By 2006 the stored water was reduced by 50 per cent and by 2012 shows open water only in the lowest parts of the main western and eastern basins?representing a reduction in surface area to 307 square kilometers?nearly 80 per cent smaller than the 2002 surface area. Standing water is almost completely absent from the central basin. From space, astronauts documented the first lake?the easternmost one?in 1998. The lakes progressively grew in depressions to the west, the westernmost filling between 2000 and 2001. This image shows lines of center-point agricultural fields near the east-basin lake nearest Lake Nasser. Sunglint on the western lake makes the water surface appear both light and dark, depending on which parts of the surface were ruffled by the wind at the moment the image was taken.

Holocene freshwater carbonate structures in the hyper-arid Gebel Uweinat region of the Sahara Desert (Southwestern Egypt)

NASA Astrophysics Data System (ADS)

Marinova, Margarita M.; Meckler, A. Nele; McKay, Christopher P.

2014-01-01

The eastern part of the Sahara is at present the driest region of the desert. Yet the extensive animal rock art in the area, presumed to depict real activities in the lives of the painters, suggests that environmental conditions were significantly different when the rock art was produced. Here we report on exploration of the area, which led to the discovery of morphologically-distinct carbonate structures that line the walls of two valleys in Gebel Uweinat, and were likely formed in standing water. The carbonate structures comprise what appear to be shoreline carbonate formations, and date back to 8100 and 9400 years BP. The chemical and morphological similarity of these formations to carbonate structures from modern lakes suggests that these lakes contained fresh, standing water suitable for human and animal use. However, the significant quartz content suggests that windblown sand was pervasive, and thus the vegetation cover may have been sparse. This discovery supports the possibility of grasslands in the area, which may have been able to support human habitation, and adds to the evidence for a wetter climate in the area in the early Holocene.

Economic analysis of critical habitat designation for the desert tortoise (Mojave population)

USGS Publications Warehouse

Schamberger, Mel; MacGillvray, Timothy J.; Draper, Dirk D.

1993-01-01

The U.S. Fish and Wildlife Service emergency 1isted the Mojave population of the desert tortoise as endangered on August 4, 1989. The Mojave population formally was listed as threatened on April 2, 1990. The Endangered Species Act of 1973, as amended, requires that the economic benefits and costs and other relevant effects of critical habitat designation be considered. The Secretary of the Interior may exclude from designation areas where the costs of designation are greater than the benefits, unless the exclusion would result in extinction of the species. Desert tortoises are threatened by an accumulation of human-and disease-related mortality accompanied by habitat destruction, degradation, and fragmentation. Many desert tortoises are illegally collected for pets, food, and commercial trade. Others are accidentally struck and killed by vehicles on roads and highways or are killed by gunshot or vehicles traveling off-highway. Raven predation on hatchling desert tortoises has increased as raven populations in the desert have risen. An upper respiratory tract disease is suspected to be a major cause of mortality in the western Mojave Desert. This presumably incurable affliction presumably is thought to be spread through the release of infected tortoises into the desert. The Service has proposed designating critical habitat in nine counties within four states. The 12 critical habitat units encompass 6.4 million acres of land, more than 80% federally owned. This region is economically and demographically diverse. Most of the land is sparsely settled and characterized as a hot desert ecosystem. Major industries in the region include entertainment and lodging (primarily in Las Vegas), property development to accommodate the rapid population growth, and services. Millions of rural acres in the region are leased by the federal government for livestock grazing and used for mining. Overall economic benefits to the affected states derived from cattle and sheep grazing in the

Paleohydrology of flash floods in small desert watersheds in western Arizona

NASA Astrophysics Data System (ADS)

House, P. Kyle; Baker, Victor R.

2001-06-01

In this study, geological, historical, and meteorological data were combined to produce a regional chronology of flood magnitude and frequency in nine small basins (7-70 km2). The chronology spans more than 1000 years and demonstrates that detailed records of flood magnitude and frequency can be compiled in arid regions with little to no conventional hydrologic information. The recent (i.e., post-1950) flood history was evaluated by comparing a 50-year series of aerial photographs with precipitation data, ages of flood-transported beer cans, anthropogenic horizons in flood sediments, postbomb 14C dates on flotsam, and anecdotal accounts. Stratigraphic analysis of paleoflood deposits extended the regional flood record in time, and associated flood magnitudes were determined by incorporating relict high-water evidence into a hydraulic model. The results reveal a general consistency among the magnitudes of the largest floods in the historical and the paleoflood records and indicate that the magnitudes and relative frequencies of actual large floods are at variance with "100-year" flood magnitudes predicted by regional flood frequency models. This suggests that the predictive equations may not be appropriate for regulatory, management, or design purposes in the absence of additional, real data on flooding. Augmenting conventional approaches to regional flood magnitude and frequency analysis with real information derived from the alternative methods described here is a viable approach to improving assessments of regional flood characteristics in sparsely gaged desert areas.

Pioneer unmanned air vehicle accomplishments during Operation Desert Storm

NASA Astrophysics Data System (ADS)

Christner, James H.

1991-12-01

This paper will describe the accomplishments and lessons learned of the Pioneer Unmanned Air Vehicle (UAV) during Operations Desert Shield and Desert Storm. The Pioneer UAV has been deployed with three branches of the U.S. military (USA, USN, and USMC) for the past four years. Although the system has compiled over 6,000 flight hours, the recent conflict in the Gulf is the first opportunity to demonstrate its true value in a combat scenario. In a relatively short time (42 days), 307 flights and 1,011 flight hours were completed on Operation Desert Storm. This, coupled with the accuracy of various weapons systems that Pioneer observed/cued for, resulted in timely target engagements. This paper will chronicle the Pioneer deployment and accomplishments on Operations Desert Shield and Desert Storm. Various employment methods, tactics, doctrine, and lessons learned will be presented.

Distributed Leadership and School Effectiveness in Egypt and Oman: An Exploratory Study

ERIC Educational Resources Information Center

Al-Harthi, Aisha Salim Ali; Al-Mahdy, Yasser F. Hendawy

2017-01-01

Purpose: The purpose of this study is to examine teachers' perceptions of the levels of distributed leadership (DL) practices and the indicators of school effectiveness (SE) in Egypt and Oman. It also investigated the role of accreditation on these perceptions. Design/methodology/approach: The study sampled 635 teachers in Egypt and Oman using the…

The building stones of ancient Egypt a gift of its geology

NASA Astrophysics Data System (ADS)

Klemm, Dietrich D.; Klemm, Rosemarie

2001-08-01

Building stones and clay-rich Nile mud were ancient Egypt's main raw construction materials. While the mud was easily accessible along the Nile river valley, the immense quantities of the different stone materials used for construction of the famous pyramids, precious temples and tombs needed a systematic quarrying organization, well arranged transport logistics over extreme distances and a high standard of stone masonry. The petrography, occurrence, and main applications of the 11 most popular stone types used in ancient Egypt are described in this contribution. Rough estimates of the scale of this mining activity, based on the volume of many different ancient quarry sites, all over Egypt, reveal that the monuments known today represent only a small fraction of the amount of building stones mined during the long, ancient Egyptian history.

Desert Survivors!

ERIC Educational Resources Information Center

Horton, Jessica; Friedenstab, Steve

2013-01-01

This article describes a special third-grade classroom unit based on the reality show "Survivor." The goal of this engaging and interactive unit was to teach students about physical and behavioral adaptations that help animals survive in various desert biomes. The activity combines research, argument, and puppet play over one week of…

Notes from the Great American Desert

ERIC Educational Resources Information Center

Grady, Marilyn L.; LaCost, Barbara Y.

2005-01-01

In the good old days, the state that is Nebraska was identified as part of the Great American Desert. In many ways, in climate and terrain, it still bears a resemblance to a desert. As a frontier or a land of pioneers, it deserves recognition. Invisibility may be one of the greatest challenges women face. One of the great flaws in the writing of…

Agreement: Desert Community College District, College of the Desert Faculty Association CTA/NEA, January 13, 1989-June 30, 1989.

ERIC Educational Resources Information Center

Desert Community Coll. District, Palm Desert, CA.

The collective bargaining agreement between the Desert Community College District and the College of the Desert Faculty Association/California Teachers Association/National Education Association is presented. This contract, covering the period from January 13, 1989 through June 30, 1989, deals with the following topics: bargaining agent…

Collective Bargaining Agreement, 1989-1992, between College of the Desert Faculty Association CTA/NEA and Desert Community College District.

ERIC Educational Resources Information Center

Desert Community Coll. District, Palm Desert, CA.

The collective bargaining agreement between Desert Community College District Board of Trustees and the College of the Desert Faculty Association/California Teachers Association/National Education Association is presented. This contract, covering the period from November 17, 1989 through June 30, 1992, deals with the following topics: bargaining…

Evaluating Micrometeorological Estimates of Groundwater Discharge from Great Basin Desert Playas.

PubMed

Jackson, Tracie R; Halford, Keith J; Gardner, Philip M

2018-03-06

Groundwater availability studies in the arid southwestern United States traditionally have assumed that groundwater discharge by evapotranspiration (ET g ) from desert playas is a significant component of the groundwater budget. However, desert playa ET g rates are poorly constrained by Bowen ratio energy budget (BREB) and eddy-covariance (EC) micrometeorological measurement approaches. Best attempts by previous studies to constrain ET g from desert playas have resulted in ET g rates that are within the measurement error of micrometeorological approaches. This study uses numerical models to further constrain desert playa ET g rates that are within the measurement error of BREB and EC approaches, and to evaluate the effect of hydraulic properties and salinity-based groundwater density contrasts on desert playa ET g rates. Numerical models simulated ET g rates from desert playas in Death Valley, California and Dixie Valley, Nevada. Results indicate that actual ET g rates from desert playas are significantly below the uncertainty thresholds of BREB- and EC-based micrometeorological measurements. Discharge from desert playas likely contributes less than 2% of total groundwater discharge from Dixie and Death Valleys, which suggests discharge from desert playas also is negligible in other basins. Simulation results also show that ET g from desert playas primarily is limited by differences in hydraulic properties between alluvial fan and playa sediments and, to a lesser extent, by salinity-based groundwater density contrasts. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

Evaluating Micrometeorological Estimates of Groundwater Discharge from Great Basin Desert Playas

NASA Astrophysics Data System (ADS)

Jackson, T.; Halford, K. J.; Gardner, P.

2017-12-01

Groundwater availability studies in the arid southwestern United States traditionally have assumed that groundwater discharge by evapotranspiration (ETg) from desert playas is a significant component of the groundwater budget. This result occurs because desert playa ETg rates are poorly constrained by Bowen Ratio energy budget (BREB) and eddy-covariance (EC) micrometeorological measurement approaches. Best attempts by previous studies to constrain ETg from desert playas have resulted in ETg rates that are below the detection limit of micrometeorological approaches. This study uses numerical models to further constrain desert playa ETg rates that are below the detection limit of EC (0.1 mm/d) and BREB (0.3 mm/d) approaches, and to evaluate the effect of hydraulic properties and salinity-based groundwater-density contrasts on desert playa ETg rates. Numerical models simulated ETg rates from desert playas in Death Valley, California and Dixie Valley, Nevada. Results indicate that actual ETg rates from desert playas are significantly below the upper detection limits provided by the BREB- and EC-based micrometeorological measurements. Discharge from desert playas contribute less than 2 percent of total groundwater discharge from Dixie and Death Valleys, which suggests discharge from desert playas is negligible in other basins. Numerical simulation results also show that ETg from desert playas primarily is limited by differences in hydraulic properties between alluvial fan and playa sediments and, to a lesser extent, by salinity-based groundwater density contrasts.

Desert Express: An Analysis on Improved Customer Service

DTIC Science & Technology

1991-09-01

Nt MARQ 3,199 Of. DESERT EXPRESS: AN ANALYSIS ON IMPROVED CUSTOMER SERVICE THESIS Thomas C Thaiheim, Majo-,r USAF AFTT/GLM/LSM,/91S-64 ?Z; W...Astq vt.: tyc a l AFIT/GLM/,LSM/91S-64 DESERT EXPRESS: AN ANALYSIS ON IMPROVED CUSTOMER SERVICE THESIS Thomas C. Thalheim, Major, USAF AFIT/GLM/LSM...91S-64 Approved for public release; distribution unlimited AFIT/GLM/LSM/91S-64 DESERT EXPRESS: AN ANALYSIS ON IMPROVED CUSTOMER SERVICE THESIS

E-Learning as an Alternative Strategy for Tourism Higher Education in Egypt

ERIC Educational Resources Information Center

Afifi, Galal M. H.

2011-01-01

Purpose: This research aims to be one of the earliest studies to investigate tourism e-learning in Egypt, thus, it will initially shed light on the current standing of e-learning in Egypt before proceeding to: identify the present status of e-learning in Egyptian tourism higher education; explore the potential advantages and drawbacks of using…

Marshak Lectureship Talk: Women in Physics in Egypt and the Arab World

NASA Astrophysics Data System (ADS)

El Sayed, Karimat

2009-03-01

Until the end of the 19th Century Science was not classified into different disciplines. The first woman named in the history of science was Merit Ptah (2700 BC) in Egypt's Valley of the Kings. In the new Egypt the first girl's school started in Cairo in 1873 and the first University in 1908. Only a few girls attended the University at that time, mainly studying the humanities. The first Egyptian woman physicist graduated in 1940 and received her PhD in nuclear physics in the USA. Nowadays the number of women in physics is increasing in all branches of physics, some of them are senior managers and others have been decorated with various prizes. In this talk some statistics will be given to show the percentage of women in physics in relation to other fields of science in Egypt. In Saudi Arabia the first girls' school started in 1964 and the first college for women, which was a section of King Abdul-Aziz University (where education is not mixed), started in 1975. I was the founder of the Physics Department of this women's section. Egyptians have played significant roles in teaching schoolchildren and university students of both sexes in all the Arab countries: Saudi Arabia, Sudan, Kuwait, Yemen, the Gulf States, Libya, Lebanon, Syria, and Jordan. But with respect to Algeria, Tunisia and Morocco, our role was limited, since classes are taught in French. Arab women living in the countries located east of Egypt still have many difficulties facing them, needing to overcome many technical, academic, and social problems, while women in the countries located west of Egypt have fewer problems. There were many problems in the early days of education in Egypt but the women of Egypt worked hard to gain the same rights as men and were able to pave the way for all Arab women. I myself met many difficulties in my early days. This talk will also describe the impact of the regional conference on Women in Physics in Africa and Middle East, which was held in Cairo in 2007.

75 FR 61467 - Desert Southwest Power, LLC; Notice of Filing

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-05

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL10-54-000] Desert Southwest Power, LLC; Notice of Filing September 27, 2010. Take notice that on September 24, 2010, Desert Southwest Power, LLC (Desert Southwest) supplemented the responses filed on September 10, 2010 with...

75 FR 57761 - Desert Southwest Power, LLC; Notice of Filing

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-22

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL10-54-000] Desert Southwest Power, LLC; Notice of Filing September 14, 2010. Take notice that on September 10, 2010, Desert Southwest Power, LLC (Desert Southwest) filed responses to the Federal Energy Regulatory Commission's...

Use of inpatient psychiatric services on a U.S. Army combat support post during Operations Desert Shield and Desert Storm: the stress of non-deployment.

PubMed

Koshes, R J; Rothberg, J M

1994-06-01

We studied the utilization of inpatient psychiatric services during Operations Desert Shield and Desert Storm (the Persian Gulf War of 1990-1991) on a U.S. Army combat support post. Inpatient psychiatric admissions and dispositions for the post's catchment area were tallied before, during, and after Operations Desert Shield and Desert Storm. Subjects included active duty soldiers (deployed soldiers were not studied while they were away from the post), their families, and retirees. Overall, there was no increase in psychiatric hospitalizations for active duty soldiers, their family members, or retirees. However, coincident with the return of soldiers from Operations Desert Shield and Desert Storm, the psychiatric proportion of all hospitalizations increased in the subpopulation of soldiers not deployed who had served less than 1 year. These soldiers in training may be more susceptible to increased stress levels associated with the return of soldiers from war because of their inadequate group bonding.

Hotline in Egypt marks change in government attitude to AIDS.

PubMed

1995-10-01

The first 24-hour AIDS hotline in the Arab world will open in Cairo, Egypt, in October 1995. The opening of the new service marks a change in attitude on the part of the Egyptian government, which has maintained a discreet AIDS control program in the past. Approval from religious leaders was necessary for the new program to begin; the United Nations Children's Fund (UNICEF) played a prominent role in negotiations. The "Counsel and Hot Line Centre," which will be based in Imbala district, will employ 19 people, including two doctors and two psychologists. The Centre was funded with US$300,000 from the Ford Foundation. Currently, 478 persons with HIV infections and 110 people with AIDS have been reported. The ministry estimates that there are 5000-7000 persons with HIV infections in Egypt. Although these figures were greeted with suspicion by organizations outside of Egypt, subsequent testing has indicated low prevalence rates for this country, despite high tourism and a large population of migrant workers.

Active Surveillance for Avian Influenza Virus, Egypt, 2010–2012

PubMed Central

Kandeil, Ahmed; El-Shesheny, Rabeh; Kayed, Ahmed S.; Gomaa, Mokhtar M.; Maatouq, Asmaa M.; Shehata, Mahmoud M.; Moatasim, Yassmin; Bagato, Ola; Cai, Zhipeng; Rubrum, Adam; Kutkat, Mohamed A.; McKenzie, Pamela P.; Webster, Robert G.; Webby, Richard J.; Ali, Mohamed A.

2014-01-01

Continuous circulation of influenza A(H5N1) virus among poultry in Egypt has created an epicenter in which the viruses evolve into newer subclades and continue to cause disease in humans. To detect influenza viruses in Egypt, since 2009 we have actively surveyed various regions and poultry production sectors. From August 2010 through January 2013, >11,000 swab samples were collected; 10% were positive by matrix gene reverse transcription PCR. During this period, subtype H9N2 viruses emerged, cocirculated with subtype H5N1 viruses, and frequently co-infected the same avian host. Genetic and antigenic analyses of viruses revealed that influenza A(H5N1) clade 2.2.1 viruses are dominant and that all subtype H9N2 viruses are G1-like. Cocirculation of different subtypes poses concern for potential reassortment. Avian influenza continues to threaten public and animal health in Egypt, and continuous surveillance for avian influenza virus is needed. PMID:24655395