Active Touch During Shrew Prey Capture

Although somatosensation in multiple whisker systems has been studied in considerable detail, relatively little information is available regarding whisker usage and movement patterns during natural behaviors. The Etruscan shrew, one of the smallest mammals, relies heavily on its whisker system to detect and kill its highly mobile insect prey. Here, we tracked whisker and body motion during prey capture. We found that shrews made periodic whisker movements (whisking) with frequencies ranging from 12 to 17 Hz. We compared shrew and rat whisking and found that shrew whisking was smaller amplitude and higher frequency than rat whisking, but that the shrew and rat whisking cycle were similar in that the velocity was higher during retraction than protraction. We were able to identify four phases during the shrew hunting behavior: (i) an immobile phase often preceding hunting, (ii) a search phase upon the initiation of hunting, (iii) a contact phase defined by whisker-to-cricket contact, and (iv) an attack phase, characterized by a rapid head movement directed toward the cricket. During the searching phase, whisking was generally rhythmic and whiskers were protracted forward. After prey contact, whisking amplitude decreased and became more variable. The final strike was associated with an abrupt head movement toward the prey with high head acceleration. Prey capture proceeded extremely fast and we obtained evidence that shrews can initiate corrective maneuvers with a minimal latency <30 ms. While the shrew's rostrum is straight and elongated during most behaviors, we show for the first time that shrews bend their rostrum during the final strike and grip their prey with a parrot beak shaped snout

Die Rolle der Transmembrandomäne von ADAM17 für die Substratproteolyse

A Disintegrin And Metalloproteinase 17 (ADAM17) is the most important sheddase of epidermal growth factor receptor (EGFR)-ligands. The protease releases, inter alia, tumor growth-factor-alpha and amphiregulin. Therefore, this enzyme is a key regulator of epithelial homeostasis, migration and proliferation. Accordingly, lack of ADAM17 in mice results in embryonic lethality accompanied by severe skin defects. Recently, first human patients were described suffering from a loss-of-function mutation in the ADAM17 gene leading to resembling epithelial defects. Dysregulation of ADAM17 is linked to diverse cutaneous diseases and disturbed epidermal barrier function. The aim of this work was to deepen the understanding of the shedding event, in particular with regard to the domain structure of ADAM17. One aspect of the ADAM-dependent substrate cleavage is that both, enzyme and substrate, need to be in close proximity. Analyzing the structure of ADAM17 and its substrates, a potential role of their transmembrane-domains can be postulated. To find out, whether there is a potential protein-interaction site within the transmembrane region, we used mutagenesis studies and analyzed the release of different EGFR-ligands. Indeed, we identified a potential interaction motif for some substrates. However, our data indicate that there is not one common motif for all substrates. Instead, we propose that the ADAM17 transmembrane region contributes to the recognition of specific substrates such as amphiregulin, while other domains might be responsible for the binding of other EGFR-ligands. Increased knowledge about the substrate selectivity of ADAM17 could lead to deeper insights into epithelial diseases caused by dysregulation of this important protease

Serum vitamin D levels of patients with oral squamous cell carcinoma (OSCC) and expression of vitamin D receptor in oral precancerous lesions and OSCC

Background: Resistance to programmed cell death (apoptosis) is a crucial factor for the carcinogenesis of oral squamous cell carcinoma (OSCC). Vitamin D (calcitriol) may overcome apoptosis resistance in tumor cells of OSCC. Vitamin D receptor (VDR) expression in oral precancerous lesions of OSCC has not been analyzed and serum vitamin D level seems to be a predictor of cancer development. Material and Methods: Expression of VDR was analyzed in normal oral mucosa (n=5), oral precursor lesions (simple hyperplasia, n=11; squamous intraepithelial neoplasia, SIN I-III, n=35), and OSCC specimen (n=42) by immunohistochemistry (IHC). Moreover, serum vitamin D levels were measured by 25(OH)D3 (calcidiol) in patients with OSCC (n=42) and correlated with IHC results. Results: Expression of VDR was significantly increased in precancerous and OSCC compared with normal tissue. Compared with SIN I-III lesions VDR expression significantly decreased in OSCC. Severe vitamin D deficiency was detected in our OSCC patient cohort but there was no significant correlation analyzed between serum vitamin D levels and corresponding immunohistochemically detected VDR expression in OSCC. Conclusions: Our survey provides the first evidence of VDR expression in precancerous lesions of OSCC. Apoptosis induction of VDR+ cells in oral precancerous lesions and OSCC by natural vitamin D or synthetic vitamin D compounds could be useful for chemoprevention. Moreover, systemically and/or locally applied, these compounds may act as sensitizers for apoptosis mediated by radio-, and chemotherapy treatment in OSCC

Estrogen and Progesterone hormone receptor expression in oral cavity cancer

Recent studies have shown an increase in the incidence of oral squamous cell carcinoma (OSCC) in younger patients. The hypothesis that tumors could be hormonally induced during pregnancy or in young female patients without the well-known risk factors alcohol or tobacco abuse seems to be plausible. Estrogen Receptor alpha (ER?) and Progesterone Receptor (PR) expression were analyzed in normal oral mucosa (n=5), oral precursor lesions (simple hyperplasia, n=11; squamous intraepithelial neoplasia, SIN I-III, n=35), and OSCC specimen. OSCCs were stratified in a young female (n=7) study cohort and older patients (n=46). In the young female study cohort three patients (n=3/7) developed OSCC during or shortly after pregnancy. Breast cancer tissues were used as positive control for ER? and PR expression. ER? expression was found in four oral precursor lesions (squamous intraepithelial neoplasia, SIN I-III, n=4/35, 11%) and in five OSCC specimen (n=5/46, 11%). The five ER? positive OSCC samples were older male patients. All patients within the young female study cohort were negatively stained for both ER? and PR. ER expression could be regarded as a seldom risk factor for OSCC. PR expression seems to be not relevant for the development of OSCC

The highly divergent Jekyll genes, required for sexual reproduction, are lineage specific for the related grass tribes Triticeae and Bromeae

Phylogenetically related groups of species contain lineage-specific genes that exhibit no sequence similarity to any genes outside the lineage. We describe here that the Jekyll gene, required for sexual reproduction, exists in two much diverged allelic variants, Jek1 and Jek3. Despite low similarity, the Jek1 and Jek3 proteins share identical signal peptides, conserved cysteine positions and direct repeats. The Jek1/Jek3 sequences are located at the same chromosomal locus and inherited in a monogenic Mendelian fashion. Jek3 has a similar expression as Jek1 and complements the Jek1 function in Jek1-deficient plants. Jek1 and Jek3 allelic variants were almost equally distributed in a collection of 485 wild and domesticated barley accessions. All domesticated barleys harboring the Jek1 allele belong to single haplotype J1-H1 indicating a genetic bottleneck during domestication. Domesticated barleys harboring the Jek3 allele consisted of three haplotypes. Jekyll-like sequences were found only in species of the closely related tribes Bromeae and Triticeae but not in other Poaceae. Non-invasive magnetic resonance imaging revealed intrinsic grain structure in Triticeae and Bromeae, associated with the Jekyll function. The emergence of Jekyll suggests its role in the separation of the Bromeae and Triticeae lineages within the Poaceae and identifies the Jekyll genes as lineage-specific

Experimental multi-level seismic performance assessment of 3D RC frame designed for damage avoidance

This paper experimentally investigates the application of damage avoidance design (DAD) philosophy to moment-resisting frames with particular emphasis on detailing of rocking interfaces. An 80% scale three-dimensional rocking beam-column joint sub-assembly designed and detailed based on damage avoidance principles is constructed and tested. Incremental dynamic analysis is used for selecting ground motion records to be applied to the sub-assembly for conducting a multi-level seismic performance assessment (MSPA). Analyses are conducted to obtain displacement demands due to the selected near- and medium-field ground motions that represent different levels of seismic hazard. Thus, predicted displacement time histories are applied to the sub-assembly for conducting quasi-earthquake displacement tests. The sub-assembly performed well reaching drifts up to 4.7% with only minor spalling occurring at rocking beam interfaces and minor flexural cracks in beams. Yielding of post-tensioning threaded bars occurred, but the sub-assembly did not collapse. The externally attached energy dissipators provided large hysteretic dissipation during large drift cycles. The sub-assembly satisfied all three seismic performance requirements, thereby verifying the superior performance of the DAD philosoph

Evaluation der Experimentierklausel nach § 6c SGB II - Untersuchungsfeld 4: Makroanalyse und regionale Vergleiche: Endbericht

"Der Beitrag von Untersuchungsfeld 4 - Makroanalyse und regionale Vergleiche - zu den Arbeiten des Forschungsverbundes zur Evaluation der Experimentierklausel nach § 6c SGB II besteht in einer Analyse der Wirkungen unterschiedlicher Formen der Aufgabenwahrnehmung im SGB II auf regionaler Ebene unter Berücksichtigung von regionalen Besonderheiten und gesamtwirtschaftlichen Wirkungszusammenhänge, darunter insbesondere interregionale Verflechtungen sowie Substitutions-, Verdrängungs- und Mitnahmeeffekte. Im Vordergrund steht dabei ein Performancevergleich von Arbeitsgemeinschaften (ARGEn) und zugelassenen kommunalen Trägern (zkT), zugespitzt in der Frage: 'Was wäre geschehen, wenn deutschlandweit entweder das ARGE-Modell oder die kommunale Trägerschaft eingeführt worden wäre?' Zur Beantwortung dieser Frage sind, über rein deskriptive Vergleiche hinaus, Untersuchungen zu den Einflussfaktoren für die Wahl der Form der Aufgabenwahrnehmung und zu den Effekten erforderlich, die sich auf der Ebene der verschiedenen Grundsicherungsstellen bezüglich der Zielsetzungen des SGB II ergeben und der jeweiligen Form der Aufgabenwahrnehmung kausal zugerechnet werden können." (Textauszug

Evaluation der Experimentierklausel nach § 6c SGB II - Untersuchungsfeld 4: Makroanalyse und regionale Vergleiche: Zwischenbericht 2007

"Im Rahmen der Evaluation der Experimentierklausel nach Paragraph 6c SGB II umfasst die Aufgabenstellung des Forschungsfeldes 4 - Makroanalyse und regionale Vergleiche - eine Analyse der regionalen Wirkungen von ARGEn und zkT (zugelassene kommunale Träger), die Analyse der gesamtwirtschaftlichen Wirkungen und ein Performancevergleich der Regionen. Insbesondere im Rahmen der Makroanalyse gilt es die Frage zu beantworten, 'Was wäre geschehen, wenn zum 1. 1. 2005 deutschlandweit entweder das ARGE-Modell oder die kommunale Trägerschaft eingeführt worden wäre?' und zwar unter besonderer Berücksichtigung regionaler Besonderheiten und Verflechtungen, sowie Substitutions-, Verdrängungs- und Mitnahmeeffekten. Bei einem Vergleich der ARGEn mit den zkT muss berücksichtigt werden, ob sich Kreise mit spezifischen Merkmalen für die eine oder die andere Form der Aufgabenwahrnehmung entschieden haben. Auf Grundlage der Vorarbeiten des Paragraph 6c-Forschungsverbundes dürften folgende Faktoren die Optionsneigung beeinflusst haben: Lokale Arbeitsmarktlage, Größe der Kommune, Finanzkraft, Sozio-geographische Merkmale, Politische Merkmale und Vorerfahrungen. Die regionalen Vergleiche dienen der Darstellung und der deskriptiven Beschreibung der Entwicklung zentraler Indikatoren für die Zielgrößen 'Integration in Erwerbstätigkeit', 'Verbesserung der Beschäftigungsfähigkeit' und 'soziale Stabilisierung' im Vergleich der drei Formen der Aufgabenwahrnehmung sowie der unterschiedlichen Organisationstypen." (Autorenreferat