Sympathetic cooling of 4^4He+^+ ions in a radiofrequency trap

We have generated Coulomb crystals of ultracold $^4$He$^+$ ions in a linear radiofrequency trap, by sympathetic cooling via laser--cooled $^9$Be$^+$. Stable crystals containing up to 150 localized He$^+$ ions at $\sim$20 mK were obtained. Ensembles or single ultracold He$^+$ ions open up interesting perspectives for performing precision tests of QED and measurements of nuclear radii. The present work also indicates the feasibility of cooling and crystallizing highly charged atomic ions using $^9$Be$^+$ as coolant.Comment: 4 pages, 2 figure

Outcomes of gallstone disease during pregnancy: a population based data linkage study

Background Gallstone disease is a leading indication for non-obstetric abdominal surgery during pregnancy. There are limited whole population data on maternal and neonatal outcomes. This population-based study aims to describe the outcomes of gallstone disease during pregnancy in an Australian setting. Methods Linked hospital, birth and mortality data for all women with singleton pregnancies in New South Wales, Australia, 2001-2012 were analysed. Exposure of interest was gallstone disease (acute biliary pancreatitis, gallstones with/without cholecystitis). Outcomes including preterm birth (spontaneous and planned), readmission, morbidity and mortality (maternal and neonatal) were compared between pregnancies with and without gallstone disease and within disease subtypes. Adjusted risk ratios (aRRs) and 99% confidence intervals were estimated using modified Poisson regression and adjusted for maternal and pregnancy factors. Results Among 1,064,089 pregnancies, 1882 (0.18%) had gallstone disease. Of these, 239 (12.7%) had an antepartum cholecystectomy and 1643 (87.3%) were managed conservatively. Of those managed conservatively, 319 (19.0%) had a postpartum cholecystectomy. Gallstone disease was associated with increased risk of preterm birth (aRR 1.3, 99% CI 1.1, 1.6) particularly planned preterm birth (aRR 1.6, 99% CI 1.2, 2.1), maternal morbidity (aRR 1.6, 99% CI 1.1, 2.3), maternal readmission (aRR 4.7, 99% CI 4.2, 5.3), and neonatal morbidity (aRR 1.4, 99% CI 1.1, 1.7). Surgery was associated with decreased risk of maternal readmission (aRR 0.4, 99% CI 0.2, 0.7). Conclusions Gallstone disease during pregnancy was associated with adverse maternal and neonatal outcomes. Most women with gallstone disease during pregnancy are managed conservatively. Surgical management was associated with decreased risk of readmission.NHMRC, AR

Electrophysiological characterization of the hyperdirect pathway and its functional relevance for subthalamic deep brain stimulation

The subthalamic nucleus (STN) receives input from various cortical areas via hyperdirect pathway (HDP) which bypasses the basal-ganglia loop. Recently, the HDP has gained increasing interest, because of its relevance for STN deep brain stimulation (DBS). To understand the HDP's role cortical responses evoked by STN-DBS have been investigated. These responses have short (<2 ms), medium (2–15 ms), and long (20–70 ms) latencies. Medium-latency responses are supposed to represent antidromic cortical activations via HDP. Together with long-latency responses the medium responses can potentially be used as biomarker of DBS efficacy as well as side effects. We here propose that the activation sequence of the cortical evoked responses can be conceptualized as high frequency oscillations (HFO) for signal analysis. HFO might therefore serve as marker for antidromic activation. Using existing knowledge on HFO recordings, this approach allows data analyses and physiological modeling to advance the pathophysiological understanding of cortical DBS-evoked high-frequency activity

S-band Polarization All Sky Survey (S-PASS): survey description and maps

We present the S-Band Polarization All Sky Survey (S-PASS), a survey of polarized radio emission over the southern sky at Dec~$< -1^\circ$ taken with the Parkes radio telescope at 2.3~GHz. The main aim was to observe at a frequency high enough to avoid strong depolarization at intermediate Galactic latitudes (still present at 1.4 GHz) to study Galactic magnetism, but low enough to retain ample Signal-to-Noise ratio (S/N) at high latitudes for extragalactic and cosmological science. We developed a new scanning strategy based on long azimuth scans, and a corresponding map-making procedure to make recovery of the overall mean signal of Stokes $Q$ and $U$ possible, a long-standing problem with polarization observations. We describe the scanning strategy, map-making procedure, and validation tests. The overall mean signal is recovered with a precision better than 0.5\%. The maps have a mean sensitivity of 0.81 mK on beam--size scales and show clear polarized signals, typically to within a few degrees of the Galactic plane, with ample S/N everywhere (the typical signal in low emission regions is 13 mK, and 98.6\% of the pixels have S/N $> 3$). The largest depolarization areas are in the inner Galaxy, associated with the Sagittarius Arm. We have also computed a Rotation Measure map combining S-PASS with archival data from the WMAP and Planck experiments. A Stokes $I$ map has been generated, with a sensitivity limited to the confusion level of 9 mK.Comment: Accepted for publication on MNRAS. Maps are available for download at the website indicated in the manuscrip

Human SWI/SNF directs sequence-specific chromatin changes on promoter polynucleosomes

Studies in humans and other species have revealed that a surprisingly large fraction of nucleosomes adopt specific positions on promoters, and that these positions appear to be determined by nucleosome positioning DNA sequences (NPSs). Recent studies by our lab, using minicircles containing only one nucleosome, indicated that the human SWI/SNF complex (hSWI/SNF) prefers to relocate nucleosomes away from NPSs. We now make use of novel mapping techniques to examine the hSWI/SNF sequence preference for nucleosome movement in the context of polynucleosomal chromatin, where adjacent nucleosomes can limit movement and where hSWI/SNF forms altered dinucleosomal structures. Using two NPS templates (5S rDNA and 601) and two hSWI/SNF target promoter templates (c-myc and UGT1A1), we observed hSWI/SNF-driven depletion of normal mononucleosomes from almost all positions that were strongly favored by assembly. In some cases, these mononucleosomes were moved to hSWI/SNF-preferred sequences. In the majority of other cases, one repositioned mononucleosome appeared to combine with an unmoved mononucleosome forming a specifically localized altered or normal dinucleosome. These effects result in dramatic, template-specific changes in nucleosomal distribution. Taken together, these studies indicate hSWI/SNF is likely to activate or repress transcription of its target genes by generating promoter sequence-specific changes in chromatin configuration

Parameters affecting ion intensities in transmission-mode Direct Analysis in Real-Time mass spectrometry

A survey of the effect of temperature, transmission module material and analysis time on ion intensities in transmission mode direct analysis in real time mass spectrometry is presented. Ion intensity profiles obtained for two related compounds are similar when analysed separately but are very different when analysed as a mixture

Thermal tool in the evaluation of the "pinhão'' (seed of Araucaria angustifolia) starch aimed agroindustrial process.

''Pinhão'' is an important source of food for inhabitants in the subtropical region of South America. Gelatinization temperatures for ''pinhão'' are smaller than for corn and cassava starches, bringing advantages in industrial processes. The ''pinhão'' starches of the 4 different provenances were subjected to dilutions of 1:4, 1:5 e 1:6, in water. The starches were evaluated using DSC to determine gelatinization characteristics of them. The results showed that the source and dilutions have influence in the gelation process of the starch.Edição dos Anais do 7º Simpósio de Análise Térmica, 2015, Bauru