High genetic diversity and distinctiveness of rear-edge climate relicts maintained by ancient tetraploidisation for Alnus glutinosa.

Populations located at the rear-edge of a species' distribution may have disproportionate ecological and evolutionary importance for biodiversity conservation in a changing global environment. Yet genetic studies of such populations remain rare. This study investigates the evolutionary history of North-African low latitude marginal populations of Alnus glutinosa Gaertn., a European tree species that plays a significant ecological role as a keystone of riparian ecosystems. We genotyped 551 adults from 19 populations located across North Africa at 12 microsatellite loci and applied a coalescent-based simulation approach to reconstruct the demographic and evolutionary history of these populations. Surprisingly, Moroccan trees were tetraploids demonstrating a strong distinctiveness of these populations within a species otherwise known as diploid. Best-fitting models of demographic reconstruction revealed the relict nature of Moroccan populations that were found to have withstood past climate change events and to be much older than Algerian and Tunisian populations. This study highlights the complex demographic history that can be encountered in rear-edge distribution margins that here consist of both old stable climate relict and more recent populations, distinctively diverse genetically both quantitatively and qualitatively. We emphasize the high evolutionary and conservation value of marginal rear-edge populations of a keystone riparian species in the context of on-going climate change in the Mediterranean region.

[Alder forests of Numidia (N.E. Algeria): floristic biodiversity, vulnerability and conservation]. / Les aulnaies de Numidie (N.E. algérien) : biodiversité floristique, vulnérabilité et conservation.

The phytoecological study of the alder forests of north-east Algeria shows that these habitats with boreal affinities harbour very high species richness (> 400 species) and complex structures, which suggest their ancient origin. They correspond phytosociologically to two syntaxa, the Campanulo alatae-Alnenion glutinosae (riparian alder forests) and the Rusco hypophylli-Alnetum glutinosae (peat-forming alder carrs), respectively. Their degraded state and their regressive dynamics, observed during the 14 years of the study, reveal their precarious situation and their rapid ongoing decline under the influence of human-induced uncontroled disturbances (cutting, burning, draining, dumping…). With regard to their ecological, historical and patrimonial importance, the alder forests of Algerian Numidia should be urgently protected, with the aim of assuring the perennity of their exceptional floristic corteges.

[Pollen analysis from two littoral marshes (Bourdim and Garaat El-Ouez) in the El-Kala wet complex (North-East Algeria). Lateglacial and Holocene history of Algerian vegetation]. / Nouvelles contributions à l'histoire tardiglaciaire et holocène de la végétation en Algérie: analyses polliniques de deux profils sédimentaires du complexe humide d'El-Kala.

The study of two pollen sequences from El-Kala marshes allowed the reconstruction of the regional vegetation history supported by eight radiocarbon dates. Pollen assemblages from Bourdim site were dominated by local input of Alnus and Salix, while regional vegetation was characterized by scattered Quercus suber forests with a well-developed Erica arborea matorral. While the vegetation dynamics recorded at Bourdim is recent (Late Holocene), the majority of the pollen diagram from Garaat El-Ouez is contemporaneous to the Late Pleniglacial and is characterized by open woodlands with Pinus, Poaceae and several heliophilous herbs. The significant values of Cedrus pollen identified in this period indicate that the region of El-Kala most probably played the role of a refugium for this tree.

Fracture of the penis: management and long-term results of surgical treatment. Experience in 300 cases.

BACKGROUND: Herein, we present the largest series of penile fracture ever published. We evaluate the clinical presentation, the outcome of the treatment and the prognosis. METHODS: We retrospectively studied patients with penile fracture treated from 1975 to 2005. RESULTS: Three hundred patients were included in this study. The mean patient age was 30 years (range, 18-68 years). Out of these patients, 57 (19%) patients were injured during sexual intercourse, whereas 180 (60%) patients were injured during masturbation. The mean time from injury to presentation was 26 hours. The diagnosis was clinical in all cases. No further investigation was needed for confirming the diagnosis. Five patients had urethral bleeding with urethral lesion. All patients were treated by immediate surgery. All of the patients had a tunica albuginea tear that was promptly repaired. At follow-up (mean time of 7 years), 14 patients presented mild curvature, which had not hindered intercourse in 10 patients. The Nesbit intervention was performed in four patients. Penile pain at intercourse developed in four patients (1.3%) and at erection in six patients (2%). Erectile dysfunction was observed in two cases (0.6%). CONCLUSION: Penile fracture has typical clinical signs. Early surgical treatment is associated with a low incidence of late complications. The high frequency in our area is neither because of physical nor genetic particularities. It is probably because of sociocultural characteristics.