U7 snRNP-specific Lsm11 protein: dual binding contacts with the 100 kDa zinc finger processing factor (ZFP100) and a ZFP100-independent function in histone RNA 3' end processing

The 3' cleavage generating non-polyadenylated animal histone mRNAs depends on the base pairing between U7 snRNA and a conserved histone pre-mRNA downstream element. This interaction is enhanced by a 100 kDa zinc finger protein (ZFP100) that forms a bridge between an RNA hairpin element upstream of the processing site and the U7 small nuclear ribonucleoprotein (snRNP). The N-terminus of Lsm11, a U7-specific Sm-like protein, was shown to be crucial for histone RNA processing and to bind ZFP100. By further analysing these two functions of Lsm11, we find that Lsm11 and ZFP100 can undergo two interactions, i.e. between the Lsm11 N-terminus and the zinc finger repeats of ZFP100, and between the N-terminus of ZFP100 and the Sm domain of Lsm11, respectively. Both interactions are not specific for the two proteins in vitro, but the second interaction is sufficient for a specific recognition of the U7 snRNP by ZFP100 in cell extracts. Furthermore, clustered point mutations in three phylogenetically conserved regions of the Lsm11 N-terminus impair or abolish histone RNA processing. As these mutations have no effect on the two interactions with ZFP100, these protein regions must play other roles in histone RNA processing, e.g. by contacting the pre-mRNA or additional processing factors.

Improved Localization of Implanted Subdural Electrode Contacts on MRI Using an Elastic Image Fusion Algorithm in Invasive EEG Recording

BACKGROUND: Accurate projection of implanted subdural electrode contacts in presurgical evaluation of pharmacoresistant epilepsy cases by invasive EEG is highly relevant. Linear fusion of CT and MRI images may display the contacts in the wrong position due to brain shift effects. OBJECTIVE: A retrospective study in five patients with pharmacoresistant epilepsy was performed to evaluate whether an elastic image fusion algorithm can provide a more accurate projection of the electrode contacts on the pre-implantation MRI as compared to linear fusion. METHODS: An automated elastic image fusion algorithm (AEF), a guided elastic image fusion algorithm (GEF), and a standard linear fusion algorithm (LF) were used on preoperative MRI and post-implantation CT scans. Vertical correction of virtual contact positions, total virtual contact shift, corrections of midline shift and brain shifts due to pneumencephalus were measured. RESULTS: Both AEF and GEF worked well with all 5 cases. An average midline shift of 1.7mm (SD 1.25) was corrected to 0.4mm (SD 0.8) after AEF and to 0.0mm (SD 0) after GEF. Median virtual distances between contacts and cortical surface were corrected by a significant amount, from 2.3mm after LF to 0.0mm after AEF and GEF (p<.001). Mean total relative corrections of 3.1 mm (SD 1.85) after AEF and 3.0mm (SD 1.77) after GEF were achieved. The tested version of GEF did not achieve a satisfying virtual correction of pneumencephalus. CONCLUSION: The technique provided a clear improvement in fusion of pre- and post-implantation scans, although the accuracy is difficult to evaluate.

Innovations in Small and Medium-Sized Family Firms

Small and medium-sized firms are a prevalent organizational form in Germany. Their importance for the German economy is indisputable. Most of them are global market leaders in their niches and are considered to be a force for innovation in the German economy. The ability to be innovative in niche markets has been identified as the antecedent of their strong, or even dominant, competitive positions in their industries. The driver of this innovation success may well be the family, which distinguishes family firms from non-family firms. Nils Kraiczy analyzes if a family influences innovation in a family firm and if this influence has only positive effects. The dissertation focuses on the impact of top management teams on innovations interacting with family firm-specific characteristics. The author shows the complexity of family influence by presenting different effects of each investigated family firm-specific characteristic on the relationship between top management team behavior and innovation.

Contrasts, Contacts, and Interconnections — Tel Kinrot as an Early Iron Age Key Site in the Northern Jordan Rift Valley at the Dawn of the 1st Millennium BCE

Ancient Kinneret (Tēl Kinrōt [Hebrew]; Tell el-ʿOrēme [Arabic]) is located on a steep limestone hill on the northwestern shores of the Sea of Galilee (2508.7529 [NIG]). The site, whose settlement history began sometime during the Pottery-Neolithic or the early Chalcolithic period, is emerging as one of the major sites for the study of urban life in the Southern Levant during the Early Iron Age (c. 1130–950 BCE). Its size, accessibility by major trade routes, and strategic location between different spheres of cultural and political influence make Tēl Kinrōt an ideal place for studying the interaction of various cultures on urban sites, as well as to approach questions of ethnicity and regionalism during one of the most debated periods in the history of the ancient Levant. The paper will briefly discuss the settlement history of the site during the Early Iron Age. However, the main focus will lie on the material culture of the late Iron Age IB city that rapidly evolved to a regional center during the transition from the 11th to the 10th century BCE. During this period, ancient Kinneret features a multitude of cultural influences that reach from Egypt via the Central Hill Country until the Northern parts of Syria and the Amuq region. While there are indisputably close ties with the ‘Aramaean’ realm, there are also strong indications that there were – at the same time – vivid socio-economic links with the West, i.e. the Southern and Northern Mediterranean coasts and their hinterland. It will be argued that the resulting ‘cultural blend’ is a typical characteristic of the material culture of the Northern Jordan Rift Valley in the advent of the emerging regional powers of the Iron Age II.

Atomic mutagenesis of the ribosomal Sarcin-Ricin-Loop to study EF-G GTPase activation

Translocation factor EF-G, possesses a low basal GTPase activity, which is stimulated by the ribosome. One potential region of the ribosome that triggers GTPase activity of EF-G is the Sarcin-Ricin-Loop (SRL) (helix 95) in domain VI of the 23S rRNA. Structural data showed that the tip of the SRL closely approaches GTP in the active center of EF-G, structural probing data confirmed that EF-G interacts with nucleotides G2655, A2660, G2661 and A2662.1-3 The exocyclic group of adenine at A2660 is required for stimulation of EF-G GTPase activity by the ribosome as demonstrated using atomic mutagenesis.4 Recent crystal structures of EF-G on the ribosome, gave more insights into the molecular mechanism of EF-G GTPase activity.5 Based on the structure of EF-Tu on the ribosome1, the following mechanism of GTPase activation was proposed: upon binding of EF-G to the ribosome, the conserved His92 (E.coli) changes its position, pointing to the γ-phosphate of GTP. In this activated state, the phosphate of residue A2662 of the SRL positions the catalytic His in its active conformation. It was further proposed that the phosphate oxygen of A2662 is involved in a charge-relay system, enabling GTP hydrolysis. In order to test this mechanism, we use the atomic mutagenesis approach, which allows introducing non-natural modifications in the SRL, in the context of the complete 70S ribosome. Therefore, we replaced one of the non-bridging oxygens of A2662 by a methyl group. A methylphosphonat is not able to position or activate a histidine, as it has no free electrons and therefore no proton acceptor function. These modified ribosomes were then tested for stimulation of EF-G GTPase activity. First experiments show that one of the two stereoisomers incorporated into ribosomes does not stimulate GTPase activity of EF-G, whereas the other is active. From this we conclude that indeed the non-bridging phosphate oxygen of A2662 is involved in EF-G GTPase activation by the ribosome. Ongoing experiments aim at revealing the contribution of this non-bridging oxygen at A2662 to the mechanism of EF-G GTPase activation at the atomic level.

Atomic mutagenesis of the ribosomal Sarcin-Ricin-Loop to study EF-G GTPase activation

Translocation factor EF-G, possesses a low basal GTPase activity, which is stimulated by the ribosome. One potential region of the ribosome that triggers GTPase activity of EF-G is the Sarcin-Ricin-Loop (SRL) (helix 95) in domain VI of the 23S rRNA. Structural data showed that the tip of the SRL closely approaches GTP in the active center of EF-G, structural probing data confirmed that EF-G interacts with nucleotides G2655, A2660, G2661 and A2662.1-3 The exocyclic group of adenine at A2660 is required for stimulation of EF-G GTPase activity by the ribosome as demonstrated using atomic mutagenesis.4 Recent crystal structures of EF-G on the ribosome, gave more insights into the molecular mechanism of EF-G GTPase activity.5 Based on the structure of EF-Tu on the ribosome1, the following mechanism of GTPase activation was proposed: upon binding of EF-G to the ribosome, the conserved His92 (E.coli) changes its position, pointing to the γ-phosphate of GTP. In this activated state, the phosphate of residue A2662 of the SRL positions the catalytic His in its active conformation. It was further proposed that the phosphate oxygen of A2662 is involved in a charge-relay system, enabling GTP hydrolysis. In order to test this mechanism, we use the atomic mutagenesis approach, which allows introducing non-natural modifications in the SRL, in the context of the complete 70S ribosome. Therefore, we replaced one of the non-bridging oxygens of A2662 by a methyl group. A methylphosphonat is not able to position or activate a histidine, as it has no free electrons and therefore no proton acceptor function. These modified ribosomes were then tested for stimulation of EF-G GTPase activity. First experiments show that one of the two stereoisomers incorporated into ribosomes does not stimulate GTPase activity of EF-G, whereas the other is active. From this we conclude that indeed the non-bridging phosphate oxygen of A2662 is involved in EF-G GTPase activation by the ribosome. Ongoing experiments aim at revealing the contribution of this non-bridging oxygen at A2662 to the mechanism of EF-G GTPase activation at the atomic level.

Metastases in normal-sized pelvic lymph nodes: detection with diffusion-weighted MR imaging

PURPOSE To prospectively assess the diagnostic performance of diffusion-weighted (DW) magnetic resonance (MR) imaging in the detection of pelvic lymph node metastases in patients with prostate and/or bladder cancer staged as N0 with preoperative cross-sectional imaging. MATERIALS AND METHODS This study was approved by an independent ethics committee. Written informed consent was obtained from all patients. Patients with no enlarged lymph nodes on preoperative cross-sectional images who were scheduled for radical resection of the primary tumor and extended pelvic lymph node dissection were enrolled. All patients were examined with a 3-T MR unit, and examinations included conventional and DW MR imaging of the entire pelvis. Image analysis was performed by three independent readers blinded to any clinical information. Metastases were diagnosed on the basis of high signal intensity on high b value DW MR images and morphologic features (shape, border). Histopathologic examination served as the standard of reference. Sensitivity and specificity were calculated, and bias-corrected 95% confidence intervals (CIs) were obtained with the bootstrap method. The Fleiss and Cohen κ and median test were applied for statistical analyses. RESULTS A total of 4846 lymph nodes were resected in 120 patients. Eighty-eight lymph node metastases were found in 33 of 120 patients (27.5%). Short-axis diameter of these metastases was less than or equal to 3 mm in 68, more than 3 mm to 5 mm in 13, more than 5 mm to 8 mm in five; and more than 8 mm in two. On a per-patient level, the three readers correctly detected metastases in 26 (79%; 95% CI: 64%, 91%), 21 (64%; 95% CI: 45%, 79%), and 25 (76%; 95% CI: 60%, 90%) of the 33 patients with metastases, with respective specificities of 85% (95% CI: 78%, 92%), 79% (95% CI: 70%, 88%), and 84% (95% CI: 76%, 92%). Analyzed according to hemipelvis, lymph node metastases were detected with histopathologic examination in 44 of 240 pelvic sides (18%); the three readers correctly detected these on DW MR images in 26 (59%; 95% CI: 45%, 73%), 19 (43%; 95% CI: 27%, 57%), and 28 (64%; 95% CI: 47%, 78%) of the 44 cases. CONCLUSION DW MR imaging enables noninvasive detection of small lymph node metastases in normal-sized nodes in a substantial percentage of patients with prostate and bladder cancer diagnosed as N0 with conventional cross-sectional imaging techniques.

Use of outdoor ranges by laying hens in different sized flocks.

In studies assessing outdoor range use of laying hens, the number of hens seen on outdoor ranges is inversely correlated to flock size. The aim of this study was to assess individual ranging behavior on a covered (veranda) and an uncovered outdoor run (free-range) in laying hen flocks varying in size. Five to ten percent of hens (aged 9–15 months) within 4 small (2–2500 hens), 4 medium (5–6000), and 4 large (≥9000) commercial flocks were fitted with radio frequency identification (RFID) tags. Antennas were placed at both sides of all popholes between the house and the veranda and the veranda and the free-range. Ranging behavior was directly monitored for approximately three weeks in combination with hourly photographs of the free-range for the distribution of hens and 6h long video recordings on two parts of the free-range during two days. Between 79 and 99% of the tagged hens were registered on the veranda at least once and between 47 and 90% were registered on the free-range at least once. There was no association between the percentage of hens registered outside the house (veranda or free-range) and flock size. However, individual hens in small and medium sized flocks visited the areas outside the house more frequently and spent more time there than hens from large flocks. Foraging behavior on the free-range was shown more frequently and for a longer duration by hens from small and medium sized flocks than by hens from large flocks. This difference in ranging behavior could account for the negative relationship between flock size and the number of hens seen outside at one point of time. In conclusion, our work describes individual birds’ use of areas outside the house within large scale commercial egg production.