Apport de la malacofaune continentale à l’alimentation des populations préhistoriques durant le Capsien supérieur en Tunisie

Les rammadiyet appartenant au Capsien supérieur, fouillées en Tunisie, sont plus nombreuses que celles du Capsien typique. Le matériel archéologique découvert se caractérise par l’abondance des coquilles d’hélicidés terrestres. La quantité d’escargots varie d’une rammadiya à une autre. Leur importance varie en fonction de l’abondance ou de la rareté de restes fauniques. D’autre part, la présence unique de gastéropodes dans une rammadiya ne suffit pas pour répondre aux besoins nutritifs humains. L’occupation humaine pourrait être de courte durée (ou de passage). Dans d’autres cas, l’installation sur un site peut être plus longue avec un groupe humain plus important, couplée à une quantité importante de coquilles de mollusques et de restes fauniques. Enfin, la domination de Sphincterochila candidissima serait en relation avec des facteurs anthropiques et/ou climatiques

L’économie de subsistance dans la cuvette de Meknassy (Sidi Bouzid, Tunisie centrale) durant l’Holocène d’après l’étude malacologique

Malacological studies using land-snail shells found on archaeological sites are very scarce in the Maghreb, although such remains are the main constituent of Holocene sites known locally as rammadiyet. In this paper, the open-air prehistoric sites studied belong to the Upper Capsian culture. The Capsian culture is one of the Epipalaeolithic cultures found in the Maghreb and is inherent to Tunisia and eastern Algeria. Capsian open-air sites are huge oval accumulations of ashes, a lot of land-snail shells and burned stones, flint material and faunal remains. The Capsian culture is divided into two subdivisions : Typical Capsian and Upper Capsian. The prehistoric sites examined in this research belong to Upper Capsian subdivisions. Different facies or ‘ regional varieties’ are known from Capsian sites. Chronologically, Capsian sites with their different facies, dated by 14C, give an age of between 10000 and 6000 BP. The Capsian groups are considered to have been the last hunter-gatherers in the Maghreb. Their way of life depended on gathering land snails, hunting wild animals and picking fruit. Standard malacological studies on rammadiyet vestiges are however still insufficient to detect the impact of land snails on the subsistence economy of Capsian communities. Our study includes simultaneously the identification of the land-snail shells (species), an attempt at determining their ages, and taphonomic analyses. It enables us to propose, for both the studied sites, a reconstruction of the contribution of land snails to the Capsian population''s food, and to try to identify the season the molluscs were collected. Our work concerned two series resulting from surveys carried out in 2005 in two stratified rammadiyet : El Oghrab and Aïn Oum Henda 1 (Meknassy, central Tunisia). Careful investigations were made regarding the stratigraphy as well as the material culture (lithic industry) and faunal remains from both sites. Faunal remains are scarce at the El Oghrab rammadiya and absent at the Aïn Oum Henda 1 rammadiya. For the malacofauna, we adopted a method of work that can be exploited for the study of collections resulting from other similar sites. After identification of the species, we quantified them by NISP (number of identified remains for each species), then calculated the minimum number of individuals (MNI). Some measurements (height and diameter) were noted for each shell. Fragments of shells were classified in different classes. A specific fragment typology was adopted (from Type 0 to Type 6). In this paper we present the results of analysis of series of malacofauna from both rammadiyet. We have highlighted the presence of nine species of land snails : Helix melanostoma, Helix sp., Eobania vermiculata, Otala lactea, Helicella ambilina, Helicella variabilis, Helicella sp., Leucochroa candidissima, Rumina decollata. Two land snail species prevail, Leucochroa candidissima and Helix melanostoma. This would seem to confirm a selection made by the human groups among the species available in their surrounding environment. This choice is also affected by the abundance of these two species in the environment of the sites depending on the season and palaeoenvironmental conditions. This selection is also manifested by the size of the land snails collected. The Capsian populations mostly collected adult gastropods and privileged the biggest individuals, which provided the most flesh. According to taphonomic studies and especially to the typology of shell fragments, the high percentage of broken shells is probably linked to trampling and not to the consumption method of these molluscs by humans. The trampling may be related to the nature of activities which took place on the site or to the topographic position of both rammadiyet (high up, near a small stream) in the Meknassy Basin. This was a stopping place for prehistoric humans coming from the region of Gafsa and the west (the Tebessa high plateaux) and moving either northwards or towards the Mediterranean coast. The important quantity of broken shells would seem to be the result of these successive passages of groups. The presence of a marine shell (Columbella rustica) shows another aspect of the behaviour of Capsian groups : we presume there were exchanges between the Capsian populations and coastal communities. The gathering and consumption of land snails at these sites seem to have been seasonal. We note changes in the amount of each species (NISP) and the composition of the species spectrum from different levels of the El Oghrab rammadiya. The gathering of land snails mainly occurred during the spring and autumn. This seasonality helps us to reconstitute the way of life of Capsian communities. These groups, the last hunter-gatherers in Tunisia and Algeria, survived mainly by gathering land snails and some occasional hunting activity. These results help to reconstitute environments and the Capsian culture but still require additional examination of material from other rammadiyet in Tunisia. The malacological species consumed by the prehistoric humans occupied a wetter environment than the current one. Nowadays these species of snails (Leucochroa candidissima, Helicella sp., Helix melanostoma) are extremely rare, even absent, indicating increased aridity in central Tunisia. When the Capsian communities disappeared and Neolithic Capsian-tradition groups appeared there was no change in the consumption of land snails. Capsian-tradition Neolithic populations continued to gather and consume terrestrial snails as well as some domestic fauna.Les études malacologiques portant sur les escargots terrestres provenant de sites archéologiques restent très rares au Maghreb alors que ces restes coquillers forment la principale composante des sites holocènes appelés localement rammadiyet. Les sites préhistoriques étudiés sont de plein air et appartiennent au Capsien supérieur. La culture capsienne est l’une des cultures de l’Épipaléolithique au Maghreb. Elle est représentée en Tunisie et dans la partie orientale de l’Algérie. Chronologiquement, les sites attribuables au Capsien avec ses différents faciès, ont été datés au 14C et donnent un âge compris entre 10000 et 6000 BP. Les groupes capsiens sont considérés comme les derniers chasseurs-cueilleurs du Maghreb. Le mode de vie de ces derniers était lié à la collecte d’escargots, la chasse d’animaux sauvages et à la cueillette de fruits. Les études malacologiques standard effectuées sur les restes provenant des rammadiyet restent cependant insuffisantes pour appréhender l’impact des mollusques terrestres sur l’économie de subsistance des populations capsiennes. Cette étude comprend à la fois l’identification des coquilles d’escargots terrestres, un essai de détermination de leur âge et des analyses taphonomiques. Elle nous permet de proposer, pour les deux sites étudiés, une reconstitution de l’apport des coquilles terrestres à l’alimentation des populations capsiennes et de tenter l’identification de la saison de la récolte des mollusques. Nous avons essayé, dans notre travail portant sur deux séries provenant de sondages pratiqués en 2005 dans les rammadiyet El Oghrab et de l’Aïn Oum Henda 1 (Meknassy, Tunisie centrale), d’adopter une méthode de travail reproductible pour l’étude de collections provenant d’autres sites semblables. L’analyse des séries de malacofaune provenant de ces deux rammadiyet montre au total sept espèces malacologiques terrestres identifiées. Deux espèces prédominent, qui sont Leucochroa candidissima et Helix melanostoma. Cela serait l’indice d’une sélection faite par l’homme parmi les espèces disponibles dans son milieu environnant. Ce choix est aussi conditionné par l’abondance de ces deux espèces dans l’environnement des sites selon les saisons et les conditions paléoenvironnementales. Cette sélection se manifeste également au niveau de la taille des escargots terrestres ramassés. L’homme capsien collectait la plupart des gastéropodes à l’âge adulte et privilégiait les individus les plus grands et les plus pourvus de chair. D’après l’étude taphonomique et surtout la typologie des fragments coquilliers, le pourcentage élevé des coquilles brisées est vraisemblablement lié au piétinement et non pas à la méthode de consommation de ces mollusques par l’homme. Le piétinement peut être lié à la nature des activités qui ont eu lieu sur le site ou à la position topographique des deux rammadiyet (en hauteur, à côté d’un cours d’eau) dans la cuvette de Meknassy, lieu de passage obligatoire par la cuvette des populations préhistoriques venant de la région de Gafsa et de l’ouest (des hauts plateaux de Tébessa) et allant soit vers le nord soit vers la côte méditerranéenne. De ces passages successifs résulteraient cette quantité importante de coquilles cassées. La présence d’un coquillage marin montre un autre aspect du quotidien de vie de l’homme capsien : l’échange entre les hommes capsiens et les populations côtières. La récolte et la consommation des hélicidés de ces sites semblent saisonnières. La collecte s’effectuait principalement au cours du printemps et de l’automne. Cet essai de saisonnalité nous aide à reconstituer le mode de vie des hommes capsiens. Ces groupes humains, derniers chasseurs-cueilleurs en Tunisie et en Algérie, vivaient principalement de la collecte des escargots terrestres et occasionnellement de l’activité cynégétique. Les espèces malacologiques collectées vivaient dans un environnement plus humide que l’actuel. De nos jours ces espèces d’escargots sont extrêmement rares, voire absentes, ce qui indique un accroissement de l’aridité en Tunisie centrale.Saafi Ismail, Aouadi Nabiha, Dupont Catherine, Belhouchet Lotfi. L’économie de subsistance dans la cuvette de Meknassy (Sidi Bouzid, Tunisie centrale) durant l’Holocène d’après l’étude malacologique . In: Bulletin de la Société préhistorique française, tome 110, n°4, 2013. pp. 703-718

Lower limbs micro-loading acutely attenuates repeated change-of-direction performance in male youth during small-sided soccer games

Abstract Background Soccer players often wear light-weighted wearable resistance (WR) attached to different body parts during the warm-up period with the aim to improve measures of physical fitness. However, the effect of WR on physical performance is unknown. This study evaluated the effects of WR with different micro-loadings on repeated change-of-direction (RCoD) performance while executing small-sided soccer games (SSG). Methods Twenty male soccer players aged 16.0 ± 1.5 years (body mass 74.0 ± 7.4 kg, body-height 175.0 ± 10.0 cm) volunteered to participate in this study. Following a within-subject study design, players performed four specific warm-up protocols in randomized order with a rest of 72 h between protocols: (1) WR micro-loadings with 0.1% of body mass (WR0.1); (2) WR micro-loadings with 0.2% of body mass (WR0.2); (3) WR micro-loadings with 0.3% of body mass (WR0.3); (4) no WR (control = CONT). After the warm-up protocols, players performed 2 sets of 20-min SSG. The RCoD was collected at the 8th min of SSG (SSG 1–8 min), the 15th min of SSG1 (SSG1-15 min), and at the 15th min of SSG2 (SSG2-15 min). Outcomes included mean and total RCoD indices (i.e., mean time and total time for each condition). Results Based on the outcomes of a two-way repeated measures analysis of variance (ANOVA), WR0.1 and WR0.2 were more effective than control in dampening the decrease of RCoD’s total time during SSG1-8 min, and SSG2-15 min (small ES: 0.24–0.35; p < 0.05). However, no significant differences were observed between WR0.3 and control. In addition, WR0.1 and WR0.2 significantly affected the decreases in RCoD’s mean best time during SSG1 and SSG2 which was observed in the unloaded condition (CONT) and consequently displayed a lower rate of RCoD performance decrease. Conclusion This study reports that wearing lower extremity WRs with micro-loads of 0.1% or 0.2% of body mass attenuates physical fatigue indicated in attenuated RCoD performance while executing SSG

Perforated La,d snails shells in western Mediterranean during late Pleistocene-early Holocene: preliminary study

International audienceSince the beginning of the 20th century, certain works (e.g. Debruge and Mercier, 1912, Debruge, 1910) have mentioned the presence of terrestrial snail shells pierced in archaeological sites of eastern Algeria. These sites are locally called “rammadiyat” (or “escargotières”). After about a century, new studies are interested in this phenomenon (Hutterer et al., 2011, 2014, Saafi et al., Submitted). Although the appearance of perforated gastropod has been identified since the Aurignacian (in the Iberian Peninsula). and the Iberomaurusian (in North Africa), they are more abundant in recent periods (Mesolithic / Capsian). In the North African sites the percentage of pierced shells does not exceed 20% of the malacological assemblage at each site. Generally, the perforations are similar in shape, size and position. However, thanks to an ethnographic study, an experimentation program and a traceological analysis some differences can be highlighted and we have been able to identify the techniques used to make the perforations and their function. Some of the perforations were made pierced by human canine teeth or by a cutting tool (blades or slats for example). In most of the cases when the perforations are located in the upper part of the spire they are used to facilitate the extraction of the animal from its shell when the latter resists in the upper part of the shell. The perforations at the last body whorl (behind the peristome) are fewer. They are related to the production of ornaments (necklaces) and, up to now, they are only present on the Maghreb. This is an example of the new role of continental malacofauna in the daily life of human groups. Moreover, due to the limited presence at a few sites, these perforated terrestrial snail shells are considered to be markers of the mobility of human groups in the western Mediterranean

Effects of Endurance Training Intensity on Pulmonary Diffusing Capacity at Rest and after Maximal Aerobic Exercise in Young Athletes

This study compared the effects of varying aerobic training programs on pulmonary diffusing capacity (TLCO), pulmonary diffusing capacity for nitric oxide (TLNO), lung capillary blood volume (Vc) and alveolar–capillary membrane diffusing capacity (DM) of gases at rest and just after maximal exercise in young athletes. Sixteen healthy young runners (16–18 years) were randomly assigned to an intense endurance training program (IET, n = 8) or to a moderate endurance training program (MET, n = 8). The training volume was similar in IET and MET but with different work intensities, and each lasted for 8 weeks. Participants performed a maximal graded cycle bicycle ergometer test to measure maximal oxygen consumption (VO₂max) and maximal aerobic power (MAP) before and after the training programs. Moreover, TLCO, TLNO and Vc were measured during a single breath maneuver. After eight weeks of training, all pulmonary parameters with the exception of alveolar volume (VA) and inspiratory volume (VI) (0.104 < p < 0889; 0.001 < ES < 0.091), measured at rest and at the end of maximal exercise, showed significant group × time interactions (p < 0.05, 0.2 < ES < 4.0). Post hoc analyses revealed significant pre-to-post decreases for maximal heart rates (p < 0.0001, ES = 3.1) and improvements for VO₂max (p = 0.006, ES = 2.22) in the IET group. Moreover, post hoc analyses revealed significant pre-to-post improvements in the IET for DM, TLNO, TLCO and Vc (0.001 < p < 0.0022; 2.68 < ES < 6.45). In addition, there were increases in Vc at rest, VO₂max, TLNO and DM in the IET but not in the MET participants after eight weeks of training with varying exercise intensities. Our findings suggest that the intensity of training may represent the most important factor in increasing pulmonary vascular function in young athletes.Medicine, Faculty ofNon UBCAnesthesiology, Pharmacology and Therapeutics, Department ofReviewedFacultyResearche

A Meta-Analysis of Autobiographical Memory Studies in Schizophrenia ă Spectrum Disorder

International audienceMeta-analyses and reviews on cognitive disorders in schizophrenia have ă shown that the most robust and common cognitive deficits are found in ă episodic memory and executive functions. More complex memory domains, ă such as autobiographical memory (AM), are also impaired in ă schizophrenia, but such impairments are reported less often despite ă their negative impact on patients' outcome. In contrast to episodic ă memory, assessed in laboratory tasks, memories of past personal events ă are much more complex and directly relate to the self. The meta-analysis ă included 20 studies, 571 patients with schizophrenia spectrum disorder, ă and 503 comparison subjects. It found moderate-to-large effect sizes ă with regard to the 3 parameters commonly used to assess AM: memory ă specificity (g = -0.97), richness of detail (g = -1.40), and conscious ă recollection (g = -0.62). These effect sizes were in the same range as ă those found in other memory domains in schizophrenia; for this reason, ă we propose that defective memories of personal past events should be ă regarded as a major cognitive impairment in this illness