Arachnida at "Reserva Ducke", Central Amazonia/Brazil

The class Arachnida contains 11 recent orders: Acari, Amblypygi, Araneae, Opiliones, Palpigradi, Pseudoscorpiones, Ricinulei, Schizomida, Scorpiones, Solifugae and Uropygi (Thelyphonida). In total, >570 families, >9165 genera and >93455 species are known world-wide. More than 136 families, >482 genera and >1547 described species occur in Amazonia. Data show, that almost one-fourth of the families presently known in the Arachnida and about 2% of the worlds described species are represented in Amazonia. In the forest reserve 'Reserva Ducke' near Manaus, the Acari-Oribatida represent 45 families, 72 genera and 35 described species, the Aranea 30 families, 143 genera and 295 described species, the Opiliones 5 families, 7 genera and 8 decribed species, the Scorpiones 2 families, 4 genera and 5 described species, the Pseudoscorpiones 6 families, 11 genera, and 15 described species, the Schizomida, 1 family, 2 genera and 2 described species, and the Amblypygi, Palpigradi, Solifugae and Uropygi (Thelyphonida) one species each. Most names are liste

"Kultur" als Form symbolischer Gewalt: Grenzziehungsprozesse im Kontext von Migration am Beispiel der Schweiz

Die Schweiz gilt international als Modell eines gelungenen Multikulturalismus, dann nämlich wenn es das Zusammenleben der vier Sprachgruppen (Romands, DeutschschweizerInnen, TessinerInnen, RäteromanInnen) betrifft. Ein sprachlicher wie auch religiöser Pluralismus ist und war stets ein Grundbaustein des Selbstverständnisses der „Willensnation“ Schweiz. Geht es aber um MigrantInnen präsentiert sich die Geschichte anders, denn in diesem Falle erscheinen religiöse und ethnisch-kulturelle Pluralität vorwiegend als problematisch. MigrantInnen gehören entsprechend den öffentlichen und politischen Diskursen nicht zum multikulturellen Staat, vielmehr sind Prozesse kollektiver Grenzziehungen und damit Schließungsmechanismen zu beobachten, in denen Ethnizität, Religion und Kultur zu den wichtigsten Differenzierungsmerkmale werden, wie Gemeinsamkeiten gegen innen (SchweizerInnen) und Barrieren gegen außen (Ausländer, Migranten, Muslims, etc.) hergestellt werden. Ich argumentiere in diesem Kapitel, dass sich dieser „Kulturdiskurs“ im letzten Jahrzehnt verstärkt hat und gleichzeitig semantischen Verschiebungen unterworfen war. Mittels der Grenzziehungsperspektive wird historisch nachvollzogen, wie Zuwanderung und Integration in politischen Debatten und Gesetz zunehmend kulturalisiert und ethnisiert wurden. Ein Fallbeispiel aus der Forschung dient mir anschließend der Veranschaulichung dieser theoretischen Perspektive und dieses „neuen“ Essentialismus

A distinct CD38+CD45RA+ population of CD4+, CD8+, and double-negative T cells is controlled by FAS.

The identification and characterization of rare immune cell populations in humans can be facilitated by their growth advantage in the context of specific genetic diseases. Here, we use autoimmune lymphoproliferative syndrome to identify a population of FAS-controlled TCRαβ+ T cells. They include CD4+, CD8+, and double-negative T cells and can be defined by a CD38+CD45RA+T-BET- expression pattern. These unconventional T cells are present in healthy individuals, are generated before birth, are enriched in lymphoid tissue, and do not expand during acute viral infection. They are characterized by a unique molecular signature that is unambiguously different from other known T cell differentiation subsets and independent of CD4 or CD8 expression. Functionally, FAS-controlled T cells represent highly proliferative, noncytotoxic T cells with an IL-10 cytokine bias. Mechanistically, regulation of this physiological population is mediated by FAS and CTLA4 signaling, and its survival is enhanced by mTOR and STAT3 signals. Genetic alterations in these pathways result in expansion of FAS-controlled T cells, which can cause significant lymphoproliferative disease

Secreted Phospholipase A2 Involvement in Neurodegeneration: Differential Testing of Prosurvival and Anti-Inflammatory Effects of Enzyme Inhibition

There is increased interest in the contribution of secreted phospholipase A2 (sPLA2) enzymes to neurodegenerative diseases. Systemic treatment with the nonapeptide CHEC-9, a broad spectrum uncompetitive inhibitor of sPLA2, has been shown previously to inhibit neuron death and aspects of the inflammatory response in several models of neurodegeneration. A persistent question in studies of sPLA2 inhibitors, as for several other anti-inflammatory and neuroprotective compounds, is whether the cell protection is direct or due to slowing of the toxic aspects of the inflammatory response. To further explore this issue, we developed assays using SY5Y (neuronal cells) and HL-60 (monocytes) cell lines and examined the effects of sPLA2 inhibition on these homogeneous cell types in vitro. We found that the peptide inhibited sPLA2 enzyme activity in both SY5Y and HL-60 cultures. This inhibition provided direct protection to SY5Y neuronal cells and their processes in response to several forms of stress including exposure to conditioned medium from HL-60 cells. In cultures of HL-60 cells, sPLA2 inhibition had no effect on survival of the cells but attenuated their differentiation into macrophages, with regard to process development, phagocytic ability, and the expression of differentiation marker CD36, as well as the secretion of proinflammatory cytokines TNF-α and IL-6. These results suggest that sPLA2 enzyme activity organizes a cascade of changes comprising both cell degeneration and inflammation, processes that could theoretically operate independently during neurodegenerative conditions. The effectiveness of sPLA2 inhibitor CHEC-9 may be due to its ability to affect both processes in isolation. Testing potential anti-inflammatory/neuroprotective compounds with these human cell lines and their conditioned media may provide a useful screening tool prior to in vivo therapeutic applications

De Novo Missense Mutations in DHX30 Impair Global Translation and Cause a Neurodevelopmental Disorder

DHX30 is a member of the family of DExH-box helicases, which use ATP hydrolysis to unwind RNA secondary structures. Here we identified six different de novo missense mutations in DHX30 in twelve unrelated individuals affected by global developmental delay (GDD), intellectual disability (ID), severe speech impairment and gait abnormalities. While four mutations are recurrent, two are unique with one affecting the codon of one recurrent mutation. All amino acid changes are located within highly conserved helicase motifs and were found to either impair ATPase activity or RNA recognition in different in vitro assays. Moreover, protein variants exhibit an increased propensity to trigger stress granule (SG) formation resulting in global translation inhibition. Thus, our findings highlight the prominent role of translation control in development and function of the central nervous system and also provide molecular insight into how DHX30 dysfunction might cause a neurodevelopmental disorder