Organochlorine pesticides (OCPs) contamination was assessed in marketable species, two fishes (tilapia and catfish) and a prawn from the Lake Taabo (Côte d'Ivoire). Lindane and endosulfan were the ...main contaminants, suggesting their current use. DDT, endrin, heptachlor plus traces of chlordane, aldrin and fipronil were also detected. In fishes and in prawns, enzymatic biomarkers exhibited significant correlations with OCPs levels, showing the feasibility of a biomonitoring. The transfer of OCPs along the aquatic food web and their immunosuppressive effects in human are discussed. This preliminary study highlights that the pesticide contamination was concomitant with the increase in infectious diseases in the bordering population of this African lake.
Reconstructing vegetation at hominin fossil sites provides us critical information about hominin palaeoenvironments and the potential role of climate in their evolution. Here we reconstruct ...vegetation from carbon isotopes of plant wax biomarkers in sediments of the Nachukui Formation in the Turkana Basin. Plant wax biomarkers were extracted from samples from a wide range of lithologies that include fluvial–lacustrine sediments and palaeosols, and therefore provide a record of vegetation from diverse depositional environments. Carbon isotope ratios from biomarkers indicate a highly dynamic vegetation structure (ca 5–100% C4 vegetation) from 2.3 to 1.7 Ma, with an overall shift towards more C4 vegetation on the landscape after about 2.1 Ma. The biomarker isotope data indicate ca 25–30% more C4 vegetation on the landscape than carbon isotope data of pedogenic carbonates from the same sequence. Our data show that the environments of early Paranthropus and Homo in this part of the Turkana Basin were primarily mixed C3–C4 to C4-dominated ecosystems. The proportion of C4-based foods in the diet of Paranthropus increases through time, broadly paralleling the increase in C4 vegetation on the landscape, whereas the diet of Homo remains unchanged. Biomarker isotope data associated with the Kokiselei archaeological site complex, which includes the site where the oldest Acheulean stone tools to date were recovered, indicate 61–97% C4 vegetation on the landscape. This article is part of the themed issue 'Major transitions in human evolution'.
Convolutional neural networks (CNNs) efficiently differentiate skin lesions by image analysis. Studies comparing a market-approved CNN in a broad range of diagnoses to dermatologists working under ...less artificial conditions are lacking.
One hundred cases of pigmented/non-pigmented skin cancers and benign lesions were used for a two-level reader study in 96 dermatologists (level I: dermoscopy only; level II: clinical close-up images, dermoscopy, and textual information). Additionally, dermoscopic images were classified by a CNN approved for the European market as a medical device (Moleanalyzer Pro, FotoFinder Systems, Bad Birnbach, Germany). Primary endpoints were the sensitivity and specificity of the CNN’s dichotomous classification in comparison with the dermatologists’ management decisions. Secondary endpoints included the dermatologists’ diagnostic decisions, their performance according to their level of experience, and the CNN’s area under the curve (AUC) of receiver operating characteristics (ROC).
The CNN revealed a sensitivity, specificity, and ROC AUC with corresponding 95% confidence intervals (CI) of 95.0% (95% CI 83.5% to 98.6%), 76.7% (95% CI 64.6% to 85.6%), and 0.918 (95% CI 0.866–0.970), respectively. In level I, the dermatologists’ management decisions showed a mean sensitivity and specificity of 89.0% (95% CI 87.4% to 90.6%) and 80.7% (95% CI 78.8% to 82.6%). With level II information, the sensitivity significantly improved to 94.1% (95% CI 93.1% to 95.1%; P < 0.001), while the specificity remained unchanged at 80.4% (95% CI 78.4% to 82.4%; P = 0.97). When fixing the CNN’s specificity at the mean specificity of the dermatologists’ management decision in level II (80.4%), the CNN’s sensitivity was almost equal to that of human raters, at 95% (95% CI 83.5% to 98.6%) versus 94.1% (95% CI 93.1% to 95.1%); P = 0.1. In contrast, dermatologists were outperformed by the CNN in their level I management decisions and level I and II diagnostic decisions. More experienced dermatologists frequently surpassed the CNN’s performance.
Under less artificial conditions and in a broader spectrum of diagnoses, the CNN and most dermatologists performed on the same level. Dermatologists are trained to integrate information from a range of sources rendering comparative studies that are solely based on one single case image inadequate.
•A market-approved convolutional neural network (CNN) trained on dermoscopic images was tested against 96 dermatologists.•Test data included a broad range of skin lesions and was compiled from external sources not involved in CNN training.•Dermatologists indicated their management decisions after reviewing clinical, dermoscopic, and textual case information.•In this setting dermatologists performed on par with the CNN's classifications based on dermoscopic images alone.
Cognitive abilities and techno-economic behaviours of hominids in the time period between 2.6-2.3 Myr have become increasingly well-documented. This time period corresponds to the oldest evidence for ...stone tools at Gona (Kada Gona, West Gona, EG 10-12, OGS 6-7), Hadar (AL 666), lower Omo valley (Ftji1, 2 & 5, Omo 57, Omo 123) in Ethiopia, and West Turkana (Lokalalei sites-LA1 & LA2C-) in Kenya. In 2002 a new palaeoanthropological site (LA1a), 100 meters south of the LA1 archaeological site, produced a first right lower molar of a juvenile hominid (KNM-WT 42718). The relative small size of the crown, its marked MD elongation and BL reduction, the relative position of the cusps, the lack of a C6 and the mild expression of a protostylid, reinforced by metrical analyses, demonstrate the distinctiveness of this tooth compared with Australopithecus afarensis, A. anamensis, A. africanus and Paranthropus boisei, and its similarity to early Homo. The LA1a site lies 2.2 m above the Ekalalei Tuff which is slightly younger than Tuff F dated to 2.34 G 0.04 Myr. This juvenile specimen represents the oldest occurrence of the genus Homo in West Turkana.
Classical stress indicators (cortisol, glycemia, hemoglobin and hematocrit) and specific red blood cell responses of enzymes involved in protection against active oxygen species (superoxide dismutase ...(SOD), catalase and peroxidase activities) were investigated in sea bass (
Dicentrarchus labrax) exposed to decreased salinity, increased temperature (physical stress) or to intoxication by metallic or organic compounds (chemical stress). Thermal stress led to a greater increase in glycemia, cortisol and peroxidase activity than osmotic shock, whereas SOD and catalase activities were more stimulated by osmotic shock. The most frequent responses of blood parameters to specific chemical intoxication involved peroxidase and MnSOD activities, and cortisolemia. Increased levels of cortisol were always found and were followed or not by enhanced glycemia. Pooling these results according to specific chemical families (metallic and organic compounds) revealed a low but general increase of total SOD activity in intoxicated fish. Some reference values were also given for each parameter, including possible variations related to sex, season or nutritional influences. The effect of fish catching, especially on glycemia and cortisolemia, was also evaluated.
This book illustrates the extraordinary diversity of ‘nomad lives’ in time and space, in a tribute to Claudine Karlin, comprising 28 texts signed by economists, geographers, historians or ...sociologists.These case studies, organized into five chapters, are invitations to meet women, men and children from all over the world. The first chapter focuses on characterizing nomads and nomadism through examples ranging from the Aka pygmies, hunter-gatherers in the Central African forest, Yakut and Kazakh herders from the Central Asian steppes, or “nomads of contemporary globalization”. The second concentrates on the material culture of camps, from the Chatelperronians in the Grotte du Bison at Arcy-sur-Cure (Yonne) to the Manteks, Kurds in contemporary Iraq. The third examines the territories and circuits inherent to nomad lives, from the first hominids of East Africa to the break in the fishing way of life brought about by the arrival of Europeans in the Magellan Strait. Magdalenian mobility trends in the Roc-aux-Sorciers (Vienne), changes in funerary practices during the Bronze and Iron Ages in the Central Asian steppes (Kazakhstan), the sexual division of labour among the Tchouktcha of Russian Siberia, etc.: the social relations with the living and the dead, in and outside the group, are the main themes of the last two chapters.But throughout the pages a single apparently simple but extremely complex question emerges. The book ends with an attempt to answer this question from the combined perspective of an archaeologist, an ethnologist and a sociologist. Because, in the end, what does being a nomad mean?
During a decade (1996–2006), ecotoxicological studies were carried out in biota of the Vaccarès Lagoon (Biosphere Reserve in Rhone Delta, France). A multicontamination was shown at all levels of the ...trophic web due to a direct bioconcentration of chemical from the medium combined with a food transfer. Here, the pollutants investigated were organochlorines, among which many compounds banned or in the course of prohibition (or restriction) (PCB, lindane,
pp′-DDE, dieldrin, aldrin, heptachlor, endosulfan…) and some substances likely still used in the Rhone River basin (diuron, fipronil). The results confirmed the ubiquity of contamination. It proves to be chronic, variable and tends to regress; however contamination levels depend on the trophic compartment. A biomagnification process was showed. A comparison of investigation methods used in other Mediterranean wetlands provides basis of discussion, and demonstrates the urgent need of modelling to assess the ecotoxicological risk in order to improve the management of such protected areas.
The Vaccarès Lagoon trophic web biomagnifies organochlorine pollutants.
Different components of the mixed function oxidase (MFO) system and the levels of fluorescent aromatic compounds in bile (FACs) were measured in Cathorops spixii in order to assess the impact of ...polycyclic aromatic hydrocarbons (PAHs). Fish were sampled in an estuary (Santos/São Vicente) with a history of contamination by PAHs, mainly due to the presence of the industrial complex of Cubatão city and of another of low anthropogenic influence (Cananéia) on the Brazilian coast. FACs were higher in fish from the polluted site, and the PAH 5 and 6-ring metabolites were the most frequent - with 14% and 15%, respectively. Levels of the different components of the MFO system showed the same variation profile as the FACs for both estuaries. Therefore, the values found for somatic indexes and biomarkers with data of bile PAH metabolites indicate the presence of organic contaminants, especially in the area subject to the influence of the industrial complex on the Santos/São Vicente estuary.
Diferentes componentes do sistema oxidase de função mista (MFO) e os níveis de compostos aromáticos fluorescentes em bile (FACS) foram determinados em Cathorops spixii a fim de avaliar o impacto de hidrocarbonetos policíclicos aromáticos (PAHs). Os peixes foram coletados em um estuário com histórico de contaminação por PAHs (Santos/São Vicente), devido principalmente a presença do complexo industrial na cidade de Cubatão e em outro com baixa influência antropogênica (Cananéia) na costa brasileira. FACs foram maiores nos peixes oriundos da área contaminada, sendo os metabolitos de HPAs com 5 e 6 anéis, os mais representativos com 14% e 15%, respectivamente. Os níveis dos diferentes componentes do sistema MFO mostraram o mesmo perfil de variação que os FACs em ambos os estuários. Portanto, os valores encontrados para os índices somáticos e os biomarcadores considerados, em associação com os dados de metabólitos biliares de PAHs, indicam a presença de contaminantes orgânicos, principalmente na área sob influência do complexo industrial no estuário de Santos/São Vicente.
European eels (
Anguilla anguilla), crucian carps (
Carassius carassius) and catfish (
Ictalurus nebulosus) were collected in three coastal locations of the Vaccarès lagoon (French National Nature ...Reserve of Camargue). The purpose of this paper is to report results of the first biomonitoring investigation in fish living in this protected coastal wetland. Residues of organochlorine (OC) contaminants (i.e. ΣPCBs, γHCH, HCB, dieldrin,
pp′-DDE) were determined in hepatic and muscular tissues, in order to compare geographical and seasonal distribution. Total exposure levels appeared to be more important in fatty fish such as eels than in crucian carps and catfish. The highest OC concentrations in liver (ΣPCB) and in muscle (γHCH) were detected in Spring in some fish coming from a site located near the mouth of a canal draining irrigation waters of rice fields. Morphophysiological parameters (condition factor, organo-somatic indexes and lipid tissue composition) were measured concomitantly. Correlations between the hepatic and muscular burdens of OC and condition factor or organo somatic indexes were infrequent and rather negative. Localization of lipid accumulation (neutral or polar lipids) depended on metabolic rates of different species and appeared related to the fish trophic level.
Human evolutionary scholars have long supposed that the earliest stone tools were made by the genus Homo and that this technological development was directly linked to climate change and the spread ...of savannah grasslands. New fieldwork in West Turkana, Kenya, has identified evidence of much earlier hominin technological behaviour. We report the discovery of Lomekwi 3, a 3.3-million-year-old archaeological site where in situ stone artefacts occur in spatiotemporal association with Pliocene hominin fossils in a wooded palaeoenvironment. The Lomekwi 3 knappers, with a developing understanding of stone’s fracture properties, combined core reduction with battering activities. Given the implications of the Lomekwi 3 assemblage for models aiming to converge environmental change, hominin evolution and technological origins, we propose for it the name ‘Lomekwian’, which predates the Oldowan by 700,000 years and marks a new beginning to the known archaeological record.
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Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
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