High-resolution imaging of compact high-velocity clouds (II)

We have imaged five compact high-velocity clouds in HI with arcmin angular- and km/s spectral-resolution using the WSRT. Supplementary total-power data, which is fully sensitive to both the cool and warm components of HI, is available for comparison for all the sources, albeit with angular resolutions that vary from 3' to 36'. The fractional HI flux in compact CNM components varies from 4% to 16% in our sample. All objects have at least one local peak in the CNM column which exceeds about 10^19 cm^-2 when observed with arcmin resolution. It is plausible that a peak column density of 1-2x10^19 cm^-2 is a prerequisite for the long-term survival of these sources. One object in our sample, CHVC120-20-443 (Davies' cloud), lies in close projected proximity to the disk of M31. This object is characterized by exceptionally broad linewidths in its CNM concentrations (more than 5 times greater than the median value). These CNM concentrations lie in an arc on the edge of the source facing the M31 disk, while the diffuse HI component of this source has a position offset in the direction of the disk. All of these attributes suggest that CHVC120-20-443 is in a different evolutionary state than most of the other CHVCs which have been studied. Similarly broad CNM linewidths have only been detected in one other object, CHVC111-07-466, which also lies in the Local Group barycenter direction and has the most extreme radial velocity known. A distinct possibility for Davies' cloud seems to be physical interaction of some type with M31. The most likely form of this interaction might be the ram-pressure or tidal- stripping by either one of M31's visible dwarf companions, M32 or NGC205, or else by a dark companion with an associated HI condensation.Comment: 12 pages, 11 (low res.) png figs, accepted for pub. in A&

Evaluation of pregnancy and delivery in 13 women who underwent resection of a sacrococcygeal teratoma during early childhood

Sacrococcygeal teratoma resection often brings changes in pelvic anatomy and physiology with possible consequences for defecation, micturition and sexual function. It is unknown, whether these changes have any gynecological and obstetric sequelae. Until now four pregnancies after sacrococcygeal teratoma resection have been described and cesarean section has been suggested to be the method of choice for delivery. We evaluated the pregnancy course and mode of delivery in women previously treated for a sacrococcygeal teratoma. The records of all patients who underwent sacrococcygeal teratoma resection after 1970 in one of the six pediatric surgical centers in the Netherlands were reviewed retrospectively. Women aged 18 years and older were eligible for participation. Patient characteristics, details about the performed operation and tumor histology were retrieved from the records. Consenting participants completed a questionnaire addressing fertility, pregnancy and delivery details. Eighty-nine women were eligible for participation; 20 could not be traced. Informed consent was received from 41, of whom 38 returned the completed questionnaire (92.7%). Thirteen of these 38 women conceived, all but one spontaneously. In total 20 infants were born, 17 by vaginal delivery and 3 by cesarean section, in one necessitated by previous intra-abdominal surgery as a consequence of sacrococcygeal teratoma resection. Conversion to a cesarean section was never necessary. None of the 25 women without offspring reported involuntary childlessness. There are no indications that resection of a sacrococcygeal teratoma in female patients is associated with reduced fertility: spontaneous pregnancy is possible and vaginal delivery is safe for mother and child, irrespective of the sacrococcygeal teratoma classification or tumor histolog

De kleine vraagbaak van het Kyoto Protocol : vragen en antwoorden over ontstaan, inwerkingtreding en uitvoering van het Kyoto Protocol

Bij gelegenheid van de officiële inwerkingtreding van het Kyoto-protocol hebben Wageningen UR, KNMI, RIVM, NWO, VU en ECN een handzaam boekje uitgegeven met antwoorden op alle vragen die u maar over de zin en onzin van Kyoto kunt bedenken. Het boekje legt uit wat het protocol inhoudt en wat het betekent voor milieu, economie en samenleving. Ook het jargon dat door klimaatonderzoekers en in het internationale onderhandelingscircuit wordt gebruikt, wordt in begrijpelijke bewoordinge

HIPASS High-Velocity Clouds: Properties of the Compact and Extended Populations

A catalog of Southern anomalous-velocity HI clouds at Decl. < +2 deg is presented, based on data from the HI Parkes All-Sky Survey (HIPASS). The improved sensitivity (5sigma: T_B = 0.04 K) and resolution (15.5') of the HIPASS data results in a substantial increase in the number of individual clouds (1956, as well as 41 galaxies) compared to previous surveys. Most high-velocity emission features, HVCs, have a filamentary morphology and are loosely organized into large complexes extending over tens of degrees. In addition, 179 compact and isolated anomalous-velocity objects, CHVCs, are identified based on their size and degree of isolation. 25% of the CHVCs originally classified by Braun & Burton (1999) are reclassified. Both the entire population of high-velocity emission features and the CHVCs alone have typical HI masses of ~ 4.5 D(kpc)^2 solar masses and have similar slopes for their column density and flux distributions. On the other hand, the CHVCs appear to be clustered and the population can be broken up into three spatially distinct groups, while the entire population of clouds is more uniformly distributed with a significant percentage aligned with the Magellanic Stream. The median velocities are V_GSR = -38 km/s for the CHVCs and -30 km/s for all of the anomalous-velocity clouds. Based on the catalog sizes, high-velocity features cover 19% of the southern sky and CHVCs cover 1%. (abridged)Comment: 32 pages, 26 figures in gif format, 2 ascii tables, to appear in the Jan 2002 issue of The Astronomical Journal, high resolution version available at http://origins.Colorado.EDU/~mputman/pubs.htm

Shot noise in ferromagnetic single electron tunneling devices

Frequency dependent current noise in ferromagnetic double junctions with Coulomb blockade is studied theoretically in the limit of sequential tunneling. Two different relaxation processes are found in the correlations between spin polarized tunneling currents; low frequency spin fluctuations and high frequency charge fluctuations. Spin accumulation in strongly asymmetric junctions is shown to lead to a negative differential resistance. We also show that large spin noise activated in the range of negative differential resistance gives rise to a significant enhancement of the current noise.Comment: 8 pages, 13 eps-figures include

Treatment and overall survival of four types of non-metastatic periampullary cancer:nationwide population-based cohort study

Background: Periampullary adenocarcinoma consists of pancreatic adenocarcinoma (PDAC), distal cholangiocarcinoma (DC), ampullary cancer (AC), and duodenal adenocarcinoma (DA). The aim of this study was to assess treatment modalities and overall survival by tumor origin. Methods: Patients diagnosed with non-metastatic periampullary cancer in 2012–2018 were identified from the Netherlands Cancer Registry. OS was studied with Kaplan–Meier analysis and multivariable Cox regression analyses, stratified by origin. Results: Among the 8758 patients included, 68% had PDAC, 13% DC, 12% AC, and 7% DA. Resection was performed in 35% of PDAC, 56% of DC, 70% of AC, and 59% of DA. Neoadjuvant and/or adjuvant therapy was administered in 22% of PDAC, 7% of DC, 7% of AC, and 12% of DA. Three-year OS was highest for AC (37%) and DA (34%), followed by DC (21%) and PDAC (11%). Adjuvant therapy was associated with improved OS among PDAC (HR = 0.62; 95% CI 0.55–0.69) and DC (HR = 0.69; 95% CI 0.48–0.98), but not AC (HR = 0.87; 95% CI 0.62–1.22) and DA (HR = 0.85; 95% CI 0.48–1.50). Conclusion: This retrospective study identified considerable differences in treatment modalities and OS between the four periampullary cancer origins in daily clinical practice. An improved OS after adjuvant chemotherapy could not be demonstrated in patients with AC and DA

An automated search for high-velocity clouds in the Leiden/Dwingeloo Survey

We describe an automated search through the Leiden/Dwingeloo HI Survey (LDS) for high-velocity clouds north of Dec=-28 deg. From the general catalog we extract a sample of isolated high-velocity clouds, CHVCs: anomalous-velocity HI clouds which are sharply bounded in angular extent with no kinematic or spatial connection to other HI features down to a limiting column density of 1.5*10^18cm^-2. This column density is an order of magnitude lower than the critical HI column density, about 2*10^19cm^-2, where the ionized fraction is thought to increase dramatically due to the extragalactic radiation field. As such, these objects are likely to provide their own shielding to ionizing radiation. Their small median angular size, of about 1 deg. FWHM, might then imply substantial distances, since the partially ionized HI skin in a power-law ionizing photon field has a typical exponential scale-length of 1 kpc. The automated search algorithm has been applied to the HIPASS and to the Leiden/Dwingeloo data sets. The results from the LDS are described here; Putman et al. (2002) describe application of this algorithm to the HIPASS material. We identify 67 CHVCs in the LDS which satisfy stringent requirements on isolation, and an additional 49 objects which satisfy somewhat less stringent requirements. Independent confirmation is available for all of these objects, either from earlier data in the literature or from new observations made with the Westerbork Synthesis Radio Telescope and reported here. The catalog includes 54 of the 65 CHVCs listed by Braun and Burton (1999) on the basis of a visual search of the LDS data.Comment: 17 pages, 19 png/jpeg figures, in review at A&A, (embedded PS figures removed due to outdated astro-ph size limits

Hospital physicians' and older patients' agreement with individualised STOPP/START-based medication optimisation recommendations in a clinical trial setting

OBJECTIVE: To evaluate the agreement of hospital physicians and older patients with individualised STOPP/START-based medication optimisation recommendations from a pharmacotherapy team. METHODS: This study was embedded within a large European, multicentre, cluster randomised controlled trial examining the effect of a structured medication review on drug-related hospital admissions in multimorbid (≥ 3 chronic conditions) older people (≥ 70 years) with polypharmacy (≥ 5 chronic medications), called OPERAM. Data from the Dutch intervention arm of this trial were used for this study. Medication review was performed jointly by a physician and pharmacist (i.e. pharmacotherapy team) supported by a Clinical Decision Support System with integrated STOPP/START criteria. Individualised STOPP/START-based medication optimisation recommendations were discussed with patients and attending hospital physicians. RESULTS: 139 patients were included, mean (SD) age 78.3 (5.1) years, 47% male and median (IQR) number of medications at admission 11 (9-14). In total, 371 recommendations were discussed with patients and physicians, overall agreement was 61.6% for STOPP and 60.7% for START recommendations. Highest agreement was found for initiation of osteoporosis agents and discontinuation of proton pump inhibitors (both 74%). Factors associated with higher agreement in multivariate analysis were: female gender (+ 17.1% [3.7; 30.4]), ≥ 1 falls in the past year (+ 15.0% [1.5; 28.5]) and renal impairment i.e. eGFR 30-50 ml/min/1.73 m2; (+ 18.0% [2.0; 34.0]). The main reason for disagreement (40%) was patients' reluctance to discontinue or initiate medication. CONCLUSION: Better patient and physician education regarding the benefit/risk balance of pharmacotherapy, in addition to more precise and up-to-date medical records to avoid irrelevant recommendations, will likely result in higher adherence with future pharmacotherapy optimisation recommendations. CLINICAL TRIAL REGISTRATION: Trial Registration Number NCT02986425

An all-sky study of compact, isolated high-velocity clouds

We combine the catalogs of compact high-velocity HI clouds extracted from the LDS and HIPASS surveys and analyze the all-sky properties of the ensemble. Five principal observables are defined for the CHVC population: (1) the spatial deployment of the objects on the sky, (2) the kinematic distribution, (3) the number distribution of observed HI column densities, (4) the number distribution of angular sizes, and (5) the number distribution of HI linewidth. Two classes of models are considered to reproduce the observed properties. The agreement of models with the data is judged by extracting these same observables from simulations, in a manner consistent with the sensitivities of the observations and explicitly taking account of Galactic obscuration. We show that models in which the CHVCs are the HI counterparts of dark-matter halos evolving in the Local Group potential provide a good match to the observables. The best-fitting populations have a maximum HI mass of 10^7 M_Sun a power-law slope of the HI mass distribution in the range -1.7 to -1.8, and a Gaussian dispersion for their spatial distributions of between 150 and 200 kpc centered on both the Milky Way and M31. Given its greater mean distance, only a small fraction of the M31 sub-population is predicted to have been detected in present surveys. An empirical model for an extended Galactic halo distribution for the CHVCs is also considered. While reproducing some aspects of the population, this class of models does not account for some key systematic features of the population.Comment: 39 pages, 29 (low res.) png figs, accepted for pub. in A&