Rise and Demise of the New Lakes of Sahara

Multispectral remote sensing data and digital elevation models were used to examine the spatial and temporal evolution of the New Lakes of Sahara in southern Egypt. These lakes appeared in September 1998, when water spilled northwestward toward the Tushka depression due to an unusual water rise in Lake Nasser induced by high precipitation in the Ethiopian Highlands. Five lakes were formed in local depressions underlain by an impermeable Paleocene shale and chalk formation. The lakes developed through three stages. (1) A rise stage occurred from September 1998 to August 2001; the area covered by the lakes reached ~1586 km2. In this stage the rate of water supply far exceeded the rate of water loss through evaporation. This stage was characterized by an early phase (August 1998-August 1999) when the area covered by the lakes increased by ~75 km2/month. This was followed by a late phase (August 1999-August 2001), in which area increase averaged ~28 km2/month. (2) A steady-state stage occurred from August 2001 to August 2003, during which the area covered by the lakes remained relatively unchanged and water lost through evaporation was continuously replaced by water supply from Lake Nasser. (3) A demise stage occurred from August 2003 to April 2007, during which water supply from Lake Nasser stopped completely and water was continuously evaporating. The area covered by the lakes decreased to ~800 km2 with an average loss of ~17 km2/month. If this trend continues, the New Lakes of Sahara will disappear completely by March 2011. The spatial distribution of the New Lakes of Sahara is strongly controlled by morphologically defined east-, north-, northeast-, and northwest-trending faults. The water recharge of the Nubian aquifer by the New Lakes of Sahara is insignificant; much of the lakes\u27 area is above an impermeable formation

Hémiptères aquatiques du nord-est de l’Algérie : distribution, phénologie et conservation

A survey, involving the sampling of 83 sites, investigated the aquatic hemiptera of northeastern Algeria, a well known hotspot of aquatic biodiversity. The study recorded 35 species with data on distribution and phenology presented and discussed. Aspects of the life history of some species (Notonecta glauca and Notonecta obliqua) were inferred from their distribution and phenology and they were found to aestivate at high altitude refuges. Insect conservation in North Africa is still embryonic, relying mainly on protected areas to provide surrogate conservation to a rich and diverse group. This is inadequate in view of the current distribution of aquatic insects, often located in unprotected habitats (intermittent streams, temporary pools, dunary ponds) and the fact that diverse manifestations of global changes (loss of habitats due to water extraction and dam construction, invasive species, habitat fragmentation) are fast eroding the biodiversity of protected areasL'échantillonnage de 83 sites à travers le complexe de zones humides du nord-est Algérien, un point chaud de la biodiversité aquatique, a permis d'identifier 35 espèces d'hémiptères aquatiques. La répartition et la phénologie des espèces sont présentées et les histoires de vie de Notoraecta glauca et Notonecta obliqua déduites. Ces deux espèces estivent dans des milieux refuges à hautes altitudes avant de redescendre se reproduire en plaine à l'automne. Diverses manifestations de changements globaux (pompage de l'eau, construction de barrages, introduction d'espèces exotiques et fragmentation des milieux) influencent négativement l'intégrité écologique des milieux de la région étudiée

Ecotoxicological Effects of Ibuprofen on Plant Growth of Vigna unguiculata L.

Despite the prevalence of the common pharmaceutical ibuprofen (IBU) in water and sediments worldwide, the effects of IBU on plants are largely unknown. This study was designed to assess the ecotoxicological effects of emerging pharmaceutical pollutant IBU on plant growth and development in a series of toxicity experiments using cowpea (Vigna unguiculata). Plant growth parameters (morphological and physicochemical) were investigated under a series of IBU concentrations (0, 400, 800, 1200, 1600, 2000 ppm IBU). IBU exposure reduced the shoot and root lengths, fresh and dry weights, leaf area, and chlorophyll a and b, carotenoid, total chlorophyll, mineral (K and Mg), glutathione reductase, and soluble protein contents. Simultaneously, increases in Ca and Mn contents, sodium translocation from roots to shoots, H2O2, malondialdehyde, superoxide dismutase, catalase, ascorbate peroxidase, and IBU uptake were observed. The amount of bioaccumulated IBU varied between 7% and 8%. IBU was translocated from roots to shoots with a translocation factor of 3–16%. The IC50 values for biomass and plant length were 1253 and 1955 ppm IBU, respectively, which is much higher than the reported levels of IBU in the environment. This study demonstrates that cowpea plants develop several morphological and physicochemical adaptations to cope under ibuprofen stress; environmentally relevant concentrations of IBU are unlikely to produce negative impacts.The authors would like to extend their sincere appreciation to the Deanship of Scientific Research at King Saud University for its funding Research group No. (RGP-199). The authors thank the Deanship of Scientific Research and RSSU at King Saud University for their technical support.Peer reviewe

Déclin précipité du Triton de Poiret Pleurodeles poireti Gervais, 1835 et autres changements du statut des amphibiens de Numidie, Algérie du Nord-Est

The worldwide erosion of biological diversity has not spared amphibians which are amongst the most affected taxa with numerous extinct or near-extinct species. Our knowledge of the status and ecology of amphibians of Algeria is still limited whereas local natural habitats are fast disappearing under a strong anthropogenic pressure. Eighty two localities were sampled between 1996 and 2010, to survey the amphibian community within Numidia, North-Eastern Algeria. Nine species, three Urodeles (Pleurodeles poireti, Pleurodeles nebulosus and Salamandra algira and six Anurans (Bufo bufo spinosus, Bufo mauritanicus, Bufo viridis, Discoglossus pictus, Hyla meridionalis and Pelophylax saharicus) were found within the region. Results suggest a marked, rapid and unexplained crash of the Algerian Newt Pleurodeles poireti, a species endemic to a small area in and around Djebel Edough (Annaba). Information on the status (abundance and distribution) of each recorded taxon is provided and conservation measures are discussed in the light of an apparent local decline of Anurans and the vulnerability of three species (S. algira, P. nebulosus and B. bufo spinosus)La crise aiguë que traverse la biodiversité à l'échelle planétaire n'a pas épargné les amphibiens qui figurent parmi les taxons les plus touchés, illustrés par le déclin prononcé ou la disparition de plusieurs espèces. Notre connaissance du statut et de l'écologie des amphibiens d'Algérie reste limitée alors que les milieux naturels locaux subissent une pression anthropique intense qui ne fait que s'accroître et qui risque de s'exacerber sous l'effet du réchauffement climatique. Dans le but d'inventorier et d'évaluer le statut du peuplement d'amphibiens du complexe de zones humides de la Numidie, «point chaud» pour de nombreux taxons aquatiques et poche relictuelle afrotropicale, nous avons échantillonné 82 sites entre 1996 et 2010. Un total de neuf espèces dont trois Urodèles (Pleurodeles poireti Gervais, 1835, Pleurodeles nebulosus (Guichenot, 1850) et Salamandra algira Bedriaga, 1883) et six Anoures (Bufo bufo spinosus, Bufo mauritanicus Schlegel, 1841, Bufo viridis Laurenti, 1768, Discoglossus picrus Otth, 1837, HYla meridionalis Boettger, 1874 et Pelophylax saharicus Boulanger in Hartert, 1913) ont été inventoriées. Un fait marquant est le déclin net, rapide et inexpliqué du Triton de Poiret Pleurodeles poireti, espèce endémique à une région limitée au Djebel Edough et ses environs, au cours des dernières années. Le statut de trois espèces (S. algira, P. nebulosus and B. bufo spinosus) semble préoccupant au vu des pressions anthropogéniques qui s'exercent sur la Numidie qui abrite 82% des amphibiens d'Algérie

Impacts des facteurs anthropiques et leur influence sur la distribution spatiale des Odonates de l’oued El Harrach (Centre-Nord de l’Algérie)

Malgré une connaissance relativement bonne de l’odonatofaune de l’Algérie et du Maghreb, de vastes régions comme le centre de l’Algérie demeurent peu explorées. Ces régions ont connu une explosion démographique et leur développement agro-industriel, au cours du siècle passé, a impacté défavorablement la plupart des écosystèmes naturels. L’oued El Harrach, un cours d’eau saisonnier qui traverse la plaine de la Mitidja, près d’Alger, est notoirement connu pour sa pollution et il représente ainsi un cas intéressant pour évaluer les impacts anthropiques sur les peuplements de macro-invertébrés dulçaquicoles. L’utilisation de plus en plus fréquente des méthodes d’évaluation mises au point pour le suivi et l’évaluation de l’intégrité écologique des cours d’eau, nous a encouragés à échantillonner les Odonates de l’oued El Harrach et mesurer divers paramètres physico-chimiques représentatifs de la qualité de l’eau du milieu. Les deux jeux de données ont été analysés conjointement pour établir une correspondance entre les deux évaluations. Les résultats indiquent une congruence entre les deux approches et soulignent le potentiel des Odonates comme bio-indicateurs utiles des conditions écologiques des écosystèmes lotiques.In spite of a relatively good knowledge of the odonatofauna of the Maghreb, some large areas like the centre of Algeria have remained little explored. These areas have witnessed a demographic explosion and an agro-industrial development over the last century which have adversely impacted most natural ecosystems. Wadi El Harrach, an intermittent river that cuts through the Mitidja plain, near Algiers, is notorious for its pollution and represents a good model to investigate anthropogenic impacts on freshwater communities. In line with the increasing use of assessment methods developed to monitor and evaluate the ecological integrity of running waters, we sampled Odonata of Wadi El Harrach and measured various abiotic parameters representative of the water quality of the habitat. Both data sets were jointly used to analyse the correspondence between the two assessments. Results indicated congruence between both approaches and highlighted the potential of Odonata as reliable bioindicators of ecological conditions of lotic ecosystems

The Odonata fauna of the Seybouse river catchment in Algeria as part of the Maghrebian biodiversity

An odonatological survey of the wadi Seybouse watershed, Northeastern Algeria, was carried out over a period of two years. Thirty five species were recorded in this previously uncharted region, including Calopteryx exul and Trithemis kirbyi. The former species, a Maghrebian endemic, has been rediscovered in Algeria after more than a century of apparent absence and the species, classified as “Endangered” in the IUCN Mediterranean Red List, is represented in Algeria by only the Seybouse population. An efficient conservation plan is needed to prevent the extinction of this emblematic species. T. kirbyi, a desert species, has considerably extended its range northward. Anthropogenic impacts were noted for the majority of sampled stations and this pressure does not bode well for the conservation of the biodiversity of wadi Seybouse. The distribution and status of each recorded species were also discussedUne étude odonatologique a été réalisée durant deux années consécutives dans le bassin-versant de la Seybouse, situé dans le nord-est algérien et pratiquement inexploré auparavant. Trente cinq espèces ont été enregistrées, dont Caloptervx exul et Trithemis kirbyi. La première, endémique du Maghreb, n'avait plus été observée en Algérie depuis plus d'un siècle et la population de l'oued Seybouse représente la seule actuellement connue en Algérie. Une protection efficace de ce bassin hydrographique est donc nécessaire afin de conserver cette espèce emblématique, en forte régression dans l'ensemble du Maghreb et considérée « en danger » par l'UICN. T kirbyi, espèce saharienne, a considérablement étendu son aire de répartition vers le nord. Une pression anthropique intense a été notée dans la majorité des stations échantillonnées. La répartition géographique et le statut de chaque espèce notée sont discutés

Prediction Models Based on Soil Characteristics for Evaluation of the Accumulation Capacity of Nine Metals by Forage Sorghum Grown in Agricultural Soils Treated with Varying Amounts of Poultry Manure

Predictive models were generated to evaluate the degree to which nine metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were absorbed by the leaves, stems and roots of forage sorghum in growing media comprising soil admixed with poultry manure concentrations of 0, 10, 20, 30 and 40 g/kg. The data revealed that the greatest contents of the majority of the metals were evident in the roots rather than in the stems and leaves. A bioaccumulation factor (BAF)  1. Translocation factor values were < 1 for all metals with the exception of Co, Cr and Ni, which displayed values of 1.20, 1.67 and 1.35 for the leaves, and 1.12, 1.23 and 1.24, respectively, for the stems. The soil pH had a negative association with metal tissues in plant parts. A positive relationship was observed with respect to plant metal contents, electrical conductivity and organic matter quantity. The designed models exhibited a high standard of data precision; any variations between the predicted and experimentally observed contents for the nine metals in the three plant tissue components were nonsignificant. Thus, it was concluded that the presented predictive models constitute a pragmatic tool to establish the safety from risk to human well-being with respect to growing forage sorghum when cultivating media fortified with poultry manure.The authors extend their appreciation to the Deputyship for Research and Innovation, Ministry of Education in Saudi Arabia for funding this research work through the project number IFP-KKU-2020/3.Peer reviewe

The origins and spread of domestic horses from the Western Eurasian steppes

This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: All collapsed and paired-end sequence data for samples sequenced in this study are available in compressed fastq format through the European Nucleotide Archive under accession number PRJEB44430, together with rescaled and trimmed bam sequence alignments against both the nuclear and mitochondrial horse reference genomes. Previously published ancient data used in this study are available under accession numbers PRJEB7537, PRJEB10098, PRJEB10854, PRJEB22390 and PRJEB31613, and detailed in Supplementary Table 1. The genomes of ten modern horses, publicly available, were also accessed as indicated in their corresponding original publications57,61,85-87.NOTE: see the published version available via the DOI in this record for the full list of authorsDomestication of horses fundamentally transformed long-range mobility and warfare. However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling at Botai, Central Asia around 3500 BC. Other longstanding candidate regions for horse domestication, such as Iberia and Anatolia, have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 BC, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 BC driving the spread of Indo-European languages. This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium BC Sintashta culture