Digital reconstruction of the inner ear of Leptictidium auderiense (Leptictida, Mammalia) and North American leptictids reveals new insight into leptictidan locomotor agility

Leptictida are basal Paleocene to Oligocene eutherians from Europe and North America comprising species with highly specialized postcranial features including elongated hind limbs. Among them, the European Leptictidium was probably a bipedal runner or jumper. Because the semicircular canals of the inner ear are involved in detecting angular acceleration of the head, their morphometry can be used as a proxy to elucidate the agility in fossil mammals. Here we provide the first insight into inner ear anatomy and morphometry of Leptictida based on high-resolution computed tomography of a new specimen of Leptictidium auderiense from the middle Eocene Messel Pit (Germany) and specimens of the North American Leptictis and Palaeictops. The general morphology of the bony labyrinth reveals several plesiomorphic mammalian features, such as a secondary crus commune. Leptictidium is derived from the leptictidan groundplan in lacking the secondary bony lamina and having proportionally larger semicircular canals than the leptictids under study. Our estimations reveal that Leptictidium was a very agile animal with agility score values (4.6 and 5.5, respectively) comparable to Macroscelidea and extant bipedal saltatory placentals. Leptictis and Palaeictops have lower agility scores (3.4 to 4.1), which correspond to the more generalized types of locomotion (e.g., terrestrial, cursorial) of most extant mammals. In contrast, the angular velocity magnitude predicted from semicircular canal angles supports a conflicting pattern of agility among leptictidans, but the significance of these differences might be challenged when more is known about intraspecific variation and the pattern of semicircular canal angles in non-primate mammals

Role of BRN2 transcription factor in proliferation and migration of the melanocyte lineage and implication of b-catenin and Dicer in the response of melanocytes to UV irradiation

PARIS5-BU Méd.Cochin (751142101) / SudocSudocFranceF

Grundtendenzen der Bevoelkerungsmigration unter den Bedingungen der Hauptstadt Berlin

HUB(11) - 83 HB 5795 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

The evolutionary puzzle of suicide

Mechanisms of self-destruction are difficult to reconcile with evolution's first rule of thumb: survive and reproduce. However, evolutionary success ultimately depends on inclusive fitness. The altruistic suicide hypothesis posits that the presence of low reproductive potential and burdensomeness toward kin can increase the inclusive fitness payoff of self-removal. The bargaining hypothesis assumes that suicide attempts could function as an honest signal of need. The payoff may be positive if the suicidal person has a low reproductive potential. The parasite manipulation hypothesis is founded on the rodent-Toxoplasma gondii host-parasite model, in which the parasite induces a "suicidal" feline attraction that allows the parasite to complete its life cycle. Interestingly, latent infection by T. gondii has been shown to cause behavioral alterations in humans, including increased suicide attempts. Finally, we discuss how suicide risk factors can be understood as nonadaptive byproducts of evolved mechanisms that malfunction. Although most of the mechanisms proposed in this article are largely speculative, the hypotheses that we raise accept self-destructive behavior within the framework of evolutionary theory. © 2013 by the authors; licensee MDPI, Basel, Switzerland.SCOPUS: re.jinfo:eu-repo/semantics/publishe

Die zentralasiatischen GUS-Republiken Kirgistan, Usbekistan, Turkmenistan, Tadschikistan Ausgangssituation und Ansatzpunkte fuer die Entwicklungszusammenarbeit

UuStB Koeln(38)-930106633 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

The Expression of the Endogenous mTORC1 Inhibitor Sestrin 2 Is Induced by UVB and Balanced with the Expression Level of Sestrin 1.

Sestrin 2 (SESN2) is an evolutionarily conserved regulator of mechanistic target of rapamycin complex 1 (mTORC1) which controls central cellular processes such as protein translation and autophagy. Previous studies have suggested that SESN2 itself is subjected to regulation at multiple levels. Here, we investigated the expression of SESN2 in the skin and in isolated skin cells. SESN2 was detected by immunofluorescence analysis in fibroblasts and keratinocytes of human skin. Differentiation of epidermal keratinocytes was not associated with altered SESN2 expression and siRNA-mediated knockdown of SESN2 did not impair stratum corneum formation in vitro. However, SESN2 was increased in both cell types when the expression of its paralog SESN1 was blocked by siRNA-mediated knock down, indicating a compensatory mechanism for the control of expression. Irradiation with UVB but not with UVA significantly increased SESN2 expression in both keratinocytes and fibroblasts. Upregulation of SESN2 expression could be completely blocked by suppression of p53. These results suggest that SESN2 is dispensable for normal epidermal keratinization but involved in the UVB stress response of skin cells

Sozialstrukturelle Veraenderungen in Angestelltengruppen unter den Bedingungen des Einsatzes informationsverarbeitender Technik

Institut fuer Geschichte der Arbeiterbewegung, Berlin, B 479- IPM 2014a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Low-income-housing in two Indian metropolises integrated housing projects and the supportive role of development cooperation

SIGLEUuStB Koeln(38)-920106833 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

UVB represses melanocyte cell migration and acts through β-catenin

The exposure of skin to ultraviolet (UV) radiation can have both beneficial and deleterious effects: it can lead, for instance, to increased pigmentation and vitamin D synthesis but also to inflammation and skin cancer. UVB may induce genetic and epigenetic alterations and have reversible effects associated with post-translational and gene regulation modifications. β-catenin is a main driver in melanocyte development; although infrequently mutated in melanoma, its cellular localization and activity are frequently altered. Here, we evaluate the consequence of UVB on β-catenin in the melanocyte lineage. We report that in vivo, UVB induces cytoplasmic/nuclear relocalization of β-catenin in melanocytes of newborn mice and adult human skin. In mouse melanocyte and human melanoma cell lines in vitro, UVB increases β-catenin stability, accumulation in the nucleus and cotranscriptional activity, leading to the repression of cell motility and velocity. The activation of the β-catenin signalling pathway and its effect on migration by UVB are increased by an inhibitor of GSK3β, and decreased by an inhibitor of β-catenin. In conclusion, UVB represses melanocyte migration and does so by acting through the GSK3-β-catenin axis

Compensatory upregulation of SESN2 upon knockdown of SESN1 in fibroblasts.

<p>Human primary fibroblasts were cultured in triplicates and transfected with siRNAs directed against SESN1 or SESN2. 48 h after the transfection, cells were harvested, RNA was extracted, transcribed into cDNA, and subjected to quantitative PCRs for SESN1 <b>(A)</b> as well as SESN2 <b>(B)</b>. Arbitrary units (a.u.) were calculated by normalizing the mRNA levels of SESN1 <b>(A)</b> or SESN2 <b>(B)</b> to B2M levels. Values relative to the expression levels in untreated cells are shown. Error bars indicate standard deviations. Student’s t-test was performed for comparisons between each treatment and the control siRNA treatment. *p < 0.05, **p < 0.01, ***p < 0.001. SESN2 protein expression was determined by Western blot analysis <b>(C)</b>. The band intensities, normalized to the intensities of the GAPDH bands on the same blot and relative to the control siRNA-treated samples, are indicated below the blot. The results are representative for three independent experiments using cells from different donors.</p