Millennial-scale oscillations and an environmental regime shift around the Middle to Late Holocene transition in the North Atlantic region based on a multiproxy record from Isfjorden, West Spitsbergen

Palynological and sedimentological analyses were performed on the sediment core HH16-1205-GC retrieved from the central Isfjorden, West Spitsbergen. The sequence, which spans the last 7000 years, revealed an overall cooling trend with an important climate shift between 4.4 and 3.8 cal. ka BP, in addition to millennial-scale oscillations. Sea-surface reconstruction from dinocyst assemblages indicates a decrease in summer sea-surface temperature, from 2.5 to 1.5 °C, and primary productivity, from 750 to 650 gC m−2 a−1 over the last 7000 years. From around 6.8 to 5.8 cal. ka BP, the sedimentological and palynological data suggest a predominant sediment supply from the inner part of the fjord, ice rafting, dense sea ice cover, strongly stratified water masses and high primary productivity. The interval from 4.4 to 3.8 cal. ka BP is marked by a layer of coarser material and a significant decrease in the grain-size mode. Our geochemical data show large-amplitude fluctuations after 2.0 cal. ka BP, while an increase in the dinocysts Impagidinium pallidum and Spiniferites elongatus from 2.0 to 1.2 cal. ka BP suggests enhanced Atlantic Water inflow. The dinocyst-based reconstructions also reveal large-amplitude millennial fluctuations in sea ice cover, summer sea-surface temperature and salinity. Wavelet analysis and cross-wavelet analysis on K/Ti ratio coupled with sea-ice estimates confirm a strong signal with a periodicity of 1200–1500 years

Intra-Arterial Thrombolysis after Full-Dose Intravenous tPA via the "Drip and Ship" Approach in Patients with Acute Ischemic Stroke: Preliminary Report

According to the "drip and ship" concept, patients who are not responsive to intravenous tissue plasminogen activator (IV-tPA) at a community hospital may be candidates for subsequent intra-arterial (IA) thrombolysis at a comprehensive stroke center. We elucidated the efficacy and safety of combined IV/IA thrombolysis via the drip and ship approach. We retrospectively reviewed patients with acute ischemic stroke who underwent combined IV/IA thrombolysis between March 2006 and June 2009. The patients were divided into two groups (inside hospital IV-tPA vs. outside hospital IV-tPA). We compared the short- and long-term clinical outcome, recanalization rate, intracranial hemorrhage after the procedure, and onset to treatment time between the two groups. A total of 23 patients with inside hospital IV-tPA and 10 patients with outside hospital IV-tPA were included. The mean pre-treatment National Institutes of Health Stroke Scale (NIHSS) scores were 15.8 and 17.5, respectively. Baseline characteristics were not significantly different between the two groups. The NIHSS score at 1 week and favorable outcome rate (modified Rankin Scale ≤2) 3 months after the procedure were not significantly different (p=0.730 and p=0.141, respectively). The rate of recanalization and intracranial hemorrhage were not significantly different (p=0.560 and p=0.730, respectively). The onset to IA thrombolysis time was also not significantly different (222.7 vs. 239.3 minutes, p=0.455). Our results suggest that initiation of IV-tPA in a community hospital with rapid transfer to a comprehensive stroke center for subsequent IA thrombolysis can be a safe and feasible therapeutic option in acute stroke management

Determination of fetal heart rate reactivity from a single 20-min window of non-stress testing in compromised fetuses

Aims: To shorten the analysis time needed for non-stress testing (NST) without decreasing efficacy in compromised fetuses. Methods: We selected 80 cases with a 5-min Apgar score <7 as a study group and 259 cases with a 5-min Apgar score ≥9 as a control group. We applied four different criteria (A, B, C, and D) to each study and control group for the first 20-min window of NST data to evaluate reactivity. Criteria A, B, and C consisted of conventional reactivity criteria according to amplitude (15 or 10 beats per minute), duration (15 or 10 s) and weeks of gestation (≤31, ≥32), and criteria D combined criteria C with approximate entropy (ApEn). Results: The sensitivity of criteria D (91.25%) was greater than the other three criteria (P<0.0001). The specificities of criteria C (96.14%) and D (99.23%) were also higher than criteria A and B (P<0.0001). The positive and negative predictive value of criteria D were better than that of criteria C (97.33 vs. 83.87, P=0.0066) and (97.35 vs. 89.89, P=0.0004), respectively. Conclusion: Adding ApEn to the conventional criteria for reactivity shortened NST analysis time without decreasing efficacy, facilitating a decision of reactivity within a single 20-min NST window.Peer Reviewe

Late quaternary glacial history and paleoceanographic reconstructions along the East Greenland continental margin: evidence from high-resolution records of stable isotopes and ice-rafted debris

SIGLEAvailable from TIB Hannover: RN 9219(241) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Late Quaternary depositional and glacial history of the Arliss Plateau off the East Siberian margin in the western Arctic Ocean

Sedimentary stratigraphy and facies analysis along with seismostratigraphic and multibeam bathymetrydata are used to reconstruct the last glacial impact on the Arliss Plateau (AP) and attendant sedimen-tation in the adjacent Chukchi Basin (CB) in the western Arctic Ocean off the East Siberian margin.Sediment core ARA02B/16B-GC from the AP lower slope captures glacier-related depositional historyduring the last estimated ca. 100 ka (Marine Isotope Stage, MIS 1 to 5c) based on regional lithostrati-graphic correlation. The sedimentary record shows distinguishable interglacial (interstadial) and glacial(stadial) patterns. The identified sedimentary facies reflect several modes of glaciogenic deposition bydrifting icebergs, suspension settling from turbid meltwater plumes and/or detached underflows, andturbidity currents. Based on strong seismic reflectors related to lithological boundaries, a downslopesubbottom profile from AP to CB is divided into seismostratigraphic units (SSU) 1 and 2 corresponding inthe core record to MIS 1e3 and MIS 3-5c, respectively. An acoustically transparent lens within SSU 2correlates on the upper slope to debris lobes downslope from the AP top covered by megascale glaciallineations. This geomorphic/sedimentary pattern indicates a glacial erosional impact on the AP andproglacial deposition of eroded sediments on the slope and in the basin. Based on the developed sedi-ment stratigraphy and facies analysis, the last debris lobe horizon was deposited in glacial/deglacialenvironments during late MIS 4 to early MIS 3. The absence of similar glaciogenic debris lobes within SSU1 indicates no direct glacial impact on the AP during the Last Glacial Maximum (LGM). These resultssuggest that the last glacial erosion of the AP occurred during or immediately after MIS 4, possibly relatedto major glaciation in northern Siberia at ~50e70 ka

The impact of the macroeconomic environment on merger activity: evidence from US time-series data

This article investigates the dynamic impact of the macroeconomic environment on aggregate merger activity in the US economy obtained from firm-level data during the period from January 1980 to December 2004. Applying time-series econometric tools to US Mergers and Acquisitions (M&A) data, we find: First, there is a long-run equilibrium relationship between the set of macroeconomic variables and four alternative measures of merger activity, implying that the macroeconomic factors plays an important role in determining the trend of aggregate merger activity in the US economy. Second, the most important macroeconomic variables in determining M&A volume include real income for the frequency-based measure of US merger activity, and stock market conditions and monetary policy for transaction value based measures of aggregate mergers. The ascending phase of business cycle provides the most favourable environment for more mergers for all four measures of merger activity. Our subsample period study provides evidence that 'corporate net cash flow' plays a significant role after 1998, which is consistent with the free-cash-flow hypothesis. Third, there are short run adjustment processes to the long-run equilibrium path in US merger activity. The main processes of impulse-response dynamics seem to finish within the 5-6 quarter period. We also discuss policy implications and directions for future extension.

Clinical and biological implications of CD133-positive and CD133-negative cells in glioblastomas

A number of recent reports have demonstrated that only CD133-positive cancer cells of glioblastoma multiforme (GBM) have tumor-initiating potential. These findings raise an attractive hypothesis that GBMs can be cured by eradicating CD133-positive cancer stem cells (CSCs), which are a small portion of GBM cells. However, as GBMs are known to possess various genetic alterations, GBMs might harbor heterogeneous CSCs with different genetic alterations. Here, we compared the clinical characteristics of two GBM patient groups divided according to CD133-positive cell ratios. The CD133-low GBMs showed more invasive growth and gene expression profiles characteristic of mesenchymal or proliferative subtypes, whereas the CD133-high GBMs showed features of cortical and well-demarcated tumors and gene expressions typical of proneuronal subtype. Both CD133-positive and CD133-negative cells purified from four out of six GBM patients produced typical GBM tumor masses in NOD-SCID brains, whereas brain mass from CD133-negative cells showed more proliferative and angiogenic features compared to that from CD133-positive cells. Our results suggest, in contrast to previous reports that only CD133-positive cells of GBMs can initiate tumor formation in vivo CD133-negative cells also possess tumor-initiating potential, which is indicative of complexity in the identification of cancer cells for therapeutic targeting