Orycteropus (Tubulidentata, Mammalia) from Langebaanweg and Baard's Quarry, Early Pliocene of South Africa

Fossil teeth and bones of aardvarks are relatively common at Langebaanweg, an Early Pliocene site in western Cape Province, South Africa. The remains are compatible in size and most details of morphology to extant Orycteropus afer, and are the earliest fossils attributed to this species. Other Late Miocene to Early Pliocene localities in Africa have yielded smaller species of aardvarks, suggesting that the extant lineage evolved in southern Africa. Morphologically the genus Orycteropus has been remarkably conservative since at least the Early Miocene but it witnessed an overall increase in size through the Neogene. The species O. afer has been morphometrically stable since the Early Pliocene. These observations indicate that the evolutionary process in aardvarks is extremely bradytelic. To cite this article: M. Pickford, C. R. Palevol 4 (2005).     

An efficient approach to automate the manual trial and error calibration of activated sludge models

An efficient approach is introduced to help automate the rather tedious manual trial and error way of model calibration currently used in activated sludge modeling practice. To this end, we have evaluated a Monte Carlo based calibration approach consisting of four steps: (i) parameter subset selection, (ii) defining parameter space, (iii) parameter sampling for Monte Carlo simulations and (iv) selecting the best Monte Carlo simulation thereby providing the calibrated parameter values. The approach was evaluated on a formerly calibrated full-scale ASM2d model for a domestic plant (located in The Netherlands), using in total 3 months of dynamic oxygen, ammonia and nitrate sensor data. The Monte Carlo calibrated model was validated successfully using ammonia, oxygen and nitrate data collected at high measurement frequency. Statistical analysis of the residuals using mean absolute error (MAE), root mean square error (RMSE) and Janus coefficient showed that the calibrated model was able to provide statistically accurate and valid predictions for ammonium, oxygen and nitrate. This shows that this pragmatic approach can perform the task of model calibration and therefore be used in practice to save the valuable time of modelers spent on this step of activated sludge modeling. The high computational demand is a downside of this approach but this can be overcome by using distributed computing. Overall we expect that the use of such systems analysis tools in the application of activated sludge models will improve the quality of model predictions and their use in decision making.     

The role of integrin alpha D beta2 (CD11d/CD18) in monocyte/macrophage migration

Integrin α_Dβ₂ (CD11d/CD18) is a multiligand macrophage receptor with recognition specificity identical to that of the major myeloid cell-specific integrin α_Mβ₂ (CD11b/CD18, Mac-1). Despite its prominent upregulation on inflammatory macrophages, the role of α_Dβ₂ in monocyte and macrophage migration is unknown. In this study, we have generated model and natural cell lines expressing different densities of α_Dβ₂ and examined their migration to various extracellular matrix proteins. When expressed at a low density, α_Dβ₂ on the surface of recombinant HEK293 cells and murine IC-21 macrophages cooperates with β₁/β₃ integrins to support cell migration. However, its increased expression on the α_Dβ₂-expressing HEK293 cells and its upregulation by PMA on the IC-21 macrophages result in increased cell adhesiveness and inhibition of cell migration. Furthermore, ligation of α_Dβ₂ with anti-α_D blocking antibodies restores β₁/β₃-driven cell migration by removing the excess α_Dβ₂-mediated adhesive bonds. Consistent with in vitro data, increased numbers of inflammatory macrophages were recovered from the inflamed peritoneum of mice after the administration of anti-α_D antibody. These results demonstrate that the density of α_Dβ₂ is critically involved in modulating macrophage adhesiveness and their migration, and suggest that low levels of α_Dβ₂ contribute to monocyte migration while α_Dβ₂ upregulation on differentiated macrophages may facilitate their retention at sites of inflammation.     

CARBON SOURCE DEPENDENCE OF THE RATIO OF δ‐AMINOLEVULINIC ACID BIOSYNTHESIS VIA THE C5 AND SHEMIN PATHWAYS IN EUGLENA GRACILIS (EUGLENOPHYCEAE)1

The ratio of two biosynthetic pathways was estimated, the C5 and Shemin pathways, to δ‐aminolevulinic acid (ALA, a biosynthetic intermediate of tetrapyrrole) from the ¹³C‐enrichment ratios (¹³C‐ER) at the carbon atoms of chl a (after conversion to methyl pheophorbide a) biosynthesized by Euglena gracilis G. A. Klebs when l ‐[3‐¹³C]alanine was used as a carbon source. On the basis of these estimations, we confirmed that ALA was efficiently biosynthesized via both the C5 and Shemin pathways in the plastids of E. gracilis, and we determined that the ratio of ALA biosynthesis via the Shemin pathway was increased in the ratio of 14%–67%, compared with that in our previous d ‐[1‐¹³C]glucose feeding experiment ( Iida et al. 2002 ). This carbon source dependence of the contributions of the two biosynthetic pathways might be related to activation of gluconeogenesis by the amino acid substrate. The methoxy carbon of the methoxycarbonyl group at C‐13² of chl a was labeled with the ¹³C‐carbon of l ‐[methyl‐¹³C]methionine derived from l ‐[3‐¹³C]alanine via [2‐¹³C]acetyl coenzyme A (CoA), through the atypical tricarboxylic acid (TCA) cycle, gluconeogenesis, and l‐ [3‐¹³C]serine. The phytyl moiety of chl a was also labeled on C‐P2, C‐P3¹, C‐P4, C‐P6, C‐P7¹, C‐P8, C‐P10, C‐P11¹, C‐P12, C‐P14, C‐P15¹, and C‐P16 from ¹³C‐isoprene (2‐[1,2‐methyl,3‐¹³C₃]methyl‐1,3‐butadiene) generated from l ‐[3‐¹³C]alanine via [2‐¹³C]acetyl CoA.     

Réflexions sur l’Acheuléen d’Anatolie

The Anatolia occupies one of the main routes for the dispersal of Homo erectus into the Eurasia. The Acheulean bifaces found on each region of Anatolia are the most important evidences of this situation. This vast distribution of the Acheulean bifaces in Anatolia indicates that all of the Anatolia should stay in the Movius Line. This means that the Movius Line should be reexaminate. Recently, the fossil remains of Homo erectus found in Dmanisi (Georgia) and their very old dates around 1.8 million years put forward the importance of Anatolia one more time. Homo erectus who came in Anatolia by following the Levant Corridor might used the Anatolian bridge for passing to the Transcaucasia. If the well-preserved cave site on the line that expands from Hatay to Kars in Anatolia founds and excavates, it will prove additional information some problems about the Homo erectus movements and distribution of Acheulean Industrial Tradition in West Asia. This paper reviews the evidence for the Acheulean in Anatolia and discusses the distribution of Acheulean bifaces in Anatolia, generally found in open air site.     

L’exploitation non alimentaire des ressources animales pendant le Magdalénien au Nord-Est de la Peninsule Ibérique. L’exemple de la grotte du Parco (Alòs de Balaguer, Lleida, Espagne)

Parco cave, discovered in 1974, has yielded more than 50 objects fashioned of hard animal parts from levels dating to later phases of the Magdalenian. In the work described here, we have undertaken a technotypological analysis of this previously unstudied bone and antler assemblage. The osseous series from Parco are homogeneous and very similar to those from nearby sites of roughly the same time period; that is to say of the late Upper Magdalenian of the peninsular Mediterranean. The latter are composed primarily of hunting weapons dominated by antler projectile points, as well as eyed bone needles and a few shell ornaments. Technological analysis shows production in which there is a tight relationship between morphological type and raw material employed. The production schema saw the removal of blanks by means of groove and splinter technique, followed by shaping of pieces by scraping and finishing of them - in some cases by abrasion.     

2d:4d, sex steroid hormones and human psychological sex differences

Studies on 2d:4d, the ratio between the second and the fourth digit, as a possible indicator of prenatal androgen exposure, have failed to produce consistent results. This paper analyzes the relation between 2d:4d, sex steroids and well-documented sex differences in characteristics such as depression, dominance, and aggressive (ART) and non-aggressive adolescent risk-taking (NART) in a comparatively large sample of adolescent boys (N = 301, mean age: 14.4 years) and girls (N = 298, mean age: 14.3 years). Boys had on average a lower 2d:4d than girls (F = 42.15; p < 0.001). With respect to boys, controlling for age and pubertal development (PD), a small but marginally significant positive association was found between 2d:4d and total testosterone (TT) (r = 0.11; p < 0.05). In girls a significant association was found between 2d:4d and SHBG (r = 0.18; p < 0.01). However, relationships between 2d:4d and hormones depended on the phase of the menstrual cycle, with 2d:4d being negatively associated with FT (B = − 0.013; p < 0.05) once a positive association between 2d:4d and FT for girls in the mid-cycle group (B = 0.019; p < 0.01) is taken into account. With respect to sex differences in characteristics, we found evidence of a relationship between 2d:4d and depression in boys (r = − 0.14; p < 0.05) but not between 2d:4d and dominance, ART or NART. No relationships were found between 2d:4d and any of these variables in girls.     

X-ray photochemistry in iron complexes from Fe(0) to Fe(IV) - Can a bug become a feature?

Under intense soft X-ray irradiation, we have observed time-dependent changes in the soft X-ray spectra of virtually all the Fe coordination complexes that we have examined, indicating chemical transformation of the compound under study. Each compound, with oxidation states ranging from Fe(IV) to Fe(0), has been studied with either Fe L-edge spectroscopy or N K-edge spectroscopy. We find that very often a well-defined spectroscopic change occurs, at least initially, which is apparently capable of straightforward interpretation in terms of X-ray induced photoreduction, photooxidation or ligand photolysis. We briefly discuss the probable chemical nature of the changes and then estimate the rate of chemical change, thereby establishing the necessary radiation dose. We also demonstrate that the photochemistry not only depends on the Fe oxidation state but also the coordination chemistry of the complex. It seems that a proper understanding of such X-ray photochemical effects could well greatly assist the assignment of soft X-ray spectra of uncharacterized metal sites.