The Interaction between the ISM and Star Formation in the Dwarf Starburst Galaxy NGC 4214

We present the first interferometric study of the molecular gas in the metal-poor dwarf starburst galaxy NGC 4214. Our map of the 12CO(1-0) emission, obtained at the OVRO millimeter array, reveals an unexpected structural wealth. We detected three regions of molecular emission in the north-west (NW), south-east (SE) and centre of NGC 4214 which are in very different and distinct evolutionary stages (total molecular mass: 5.1 x 10^6 M_sun). These differences are apparent most dramatically when the CO morphologies are compared to optical ground based and HST imaging: massive star formation has not started yet in the NW region; the well-known starburst in the centre is the most evolved and star formation in the SE complex started more recently. We derive a star formation efficiency of 8% for the SE complex. Using high--resolution VLA observations of neutral hydrogen HI and our CO data we generated a total gas column density map for NGC 4214 (HI + H_2). No clear correlation is seen between the peaks of HI, CO and the sites of ongoing star formation. This emphasizes the irregular nature of dwarf galaxies. The HI and CO velocities agree well, so do the H-alpha velocities. In total, we cataloged 14 molecular clumps in NGC 4214. Our results from a virial mass analysis are compatible with a Galactic CO-to-H_2 conversion factor for NGC 4214 (lower than what is usually found in metal-poor dwarf galaxies).Comment: accepted for publication in the AJ (February 2001), full ps file at: ftp://ftp.astro.caltech.edu/users/fw/ngc4214/walter_prep.p

Systems thinkers think About systems education under the April 2010 (volcanic ash) clouds of Austria

The fragmented nature of systems education with multiple traditions expressed in very different ways at different institutions with ultimate confusing effects on the community of learners (students, managers, policy makers, etc), led to a group of Systems Thinkers to discuss and create generic curricula for education and learning about systems for the generalist and specialist tracks. An active network of systems educators and stakeholders who can benefit from enhanced systems education in having to deal with complex issues, was also explored. In this presentation some guidelines for designing introductory and advanced courses will be discussed. The Introduction to Systemic Thinking and Practice course is intended as an introductory course for students from all disciplines. The Advanced Systemic Thinking and Practice course is intended as a more advanced course for students who are faced with complex issues that require a trans-disciplinary and integrated approach. The designs contain a set of key systems concepts and frameworks relevant to the appropriate level, along with some indicative tools and methods which will enable students to explore the concepts. The value of a Global Network of Systems Educators will also be discussed and how this network could help to fulfil the needs of managers, policy makers and society in general. An example will be given of how the integration of this network with the UQ-UNESCO/MAB Global Learning Laboratories NET could lead to more people (decision-and policy makers in Governments, managers, businesses, etc.) having the ability to practice systems thinking – all of these contributing to Systems Thinking becoming a more mainstream part of a sustainable society

Radio Sources in the 2dF Galaxy Redshift Survey. I. Radio Source Populations

We present the first results from a study of the radio continuum properties of galaxies in the 2dF Galaxy Redshift Survey, based on thirty 2dF fields covering a total area of about 100 square degrees. About 1.5% of galaxies with b(J) < 19.4 mag are detected as radio continuum sources in the NRAO VLA Sky Survey (NVSS). Of these, roughly 40% are star-forming galaxies and 60% are active galaxies (mostly low-power radio galaxies and a few Seyferts). The combination of 2dFGRS and NVSS will eventually yield a homogeneous set of around 4000 radio-galaxy spectra, which will be a powerful tool for studying the distriibution and evolution of both AGN and starburst galaxies out to redshift z=0.3.Comment: 14 pages, 7 figures, accepted for publication in PAS

Revisiting the relativistic ejection event in XTE J1550-564 during the 1998 outburst

We revisit the discovery outburst of the X-ray transient XTE J1550−564 during which relativistic jets were observed in 1998 September, and review the radio images obtained with the Australian Long Baseline Array, and light curves obtained with the Molonglo Observatory Synthesis Telescope and the Australia Telescope Compact Array. Based on Hi spectra, we constrain the source distance to between 3.3 and 4.9 kpc. The radio images, taken some 2 d apart, show the evolution of an ejection event. The apparent separation velocity of the two outermost ejecta is at least 1.3c and may be as large as 1.9c; when relativistic effects are taken into account, the inferred true velocity is ≥ 0.8c. The flux densities appear to peak simultaneously during the outburst, with a rather flat (although still optically thin) spectral index of −0.2

The association of skin autofluorescence with cardiovascular events and all-cause mortality in persons with chronic kidney disease stage 3: A prospective cohort study

BackgroundTissue advanced glycation end product (AGE) accumulation has been proposed as a marker of cumulative metabolic stress that can be assessed noninvasively by measurement of skin autofluorescence (SAF). In persons on haemodialysis, SAF is an independent risk factor for cardiovascular events (CVEs) and all-cause mortality (ACM), but data at earlier stages of chronic kidney disease (CKD) are inconclusive. We investigated SAF as a risk factor for CVEs and ACM in a prospective study of persons with CKD stage 3.Methods and findingsParticipants with estimated glomerular filtration rate (eGFR) 59 to 30 mL/min/1.73 m2 on two consecutive previous blood tests were recruited from 32 primary care practices across Derbyshire, United Kingdom between 2008 and 2010. SAF was measured in participants with CKD stage 3 at baseline, 1, and 5 years using an AGE reader (DiagnOptics). Data on hospital admissions with CVEs (based on international classification of diseases [ICD]-10 coding) and deaths were obtained from NHS Digital. Cox proportional hazards models were used to investigate baseline variables associated with CVEs and ACM. A total of 1,707 of 1,741 participants with SAF readings at baseline were included in this analysis: The mean (± SD) age was 72.9 ± 9.0 years; 1,036 (60.7%) were female, 1,681 (98.5%) were of white ethnicity, and mean (±SD) eGFR was 53.5 ± 11.9 mL/min/1.73 m2. We observed 319 deaths and 590 CVEs during a mean of 6.0 ± 1.5 and 5.1 ± 2.2 years of observation, respectively. Higher baseline SAF was an independent risk factor for CVEs (hazard ratio [HR] 1.12 per SD, 95% CI 1.03-1.22, p = 0.01) and ACM (HR 1.16, 95% CI 1.03-1.30, p = 0.01). Additionally, increase in SAF over 1 year was independently associated with subsequent CVEs (HR 1.11 per SD, 95% CI 1.00-1.22; p = 0.04) and ACM (HR 1.24, 95% CI 1.09-1.41, p = 0.001). We relied on ICD-10 codes to identify hospital admissions with CVEs, and there may therefore have been some misclassification.ConclusionsWe have identified SAF as an independent risk factor for CVE and ACM in persons with early CKD. These findings suggest that interventions to reduce AGE accumulation, such as dietary AGE restriction, may reduce cardiovascular risk in CKD, but this requires testing in prospective randomised trials. Our findings may not be applicable to more ethnically diverse or younger populations

Acceptability of the female condom in different groups of women in South Africa - A multicentred study to inform the national female condom introductory strategy

Objectives. To assess the acceptability of the female condom to different groups of women and their partners in South Africa. Design. Descriptive, cross-sectional study. Setting. Multicentre study conducted in five sites. Subjects. The study recruited 678 women from five centres-to an acceptability trial of the female condom. Acceptability and successful use varied between the centres. Outcome measures. Factors affecting successful use and willingness and intention to use the method again. Results. In total, 209 women used the condom at least once. Discontinuation rates were high, with partner reluctance to try the method as the main reason given for discontinuation at all sites. Women who had previous experience with the male condom or who received a more intensive training session generally found the device easier to use. The main issues concerning women were over-lubrication (27%) and concern that the device was too large (28%). The majority of women said that they would be interested in using the method again (86%) and would recommend it to friends (95%). Conclusions. Overcoming partner opposition is an important issue to address when introducing the method. The study was used to address the national introductory strategy of the female condom, which began in 1998

Acceptability of the female condom in different groups Of women in South Africa-A Multicentred study to inform the national female condom introductory strategy

Objectives. To assess the acceptability of the female condom to different groups of women and their partners in South Africa.Design. Descriptive, cross-sectional study.Setting. Multicentre study conducted in five sites.Subjects. The study recruited 678 women from five centres to an acceptability trial of the female condom. Acceptability and successful use varied between the centres. Outcome measures. Factors affecting successful use and willingness and intention to use the method again.Results. In total, 209 women used the condom at least once. Discontinuation rates were high, with partner reluctance to try the method as the main reason given for discontinuation at all sites. Women who had previous experience with the male condom or who received a more intensive training session generally found the device easier to use. The main issues concerning women were over-lubrication (27%) and concern that the device was too large (28%). The majority of women said that they would be interested in using the method again (86%) and would recommend it to friends (95%).Conclusions. Overcoming partner opposition is an important issue to address when introducing the method. The study was used to address the national introductory strategy of the female condom, which began in 1998

How to suppress undesired synchronization

It is delightful to observe the emergence of synchronization in the blinking of fireflies to attract partners and preys. Other charming examples of synchronization can also be found in a wide range of phenomena such as, e.g., neurons firing, lasers cascades, chemical reactions, and opinion formation. However, in many situations the formation of a coherent state is not pleasant and should be mitigated. For example, the onset of synchronization can be the root of epileptic seizures, traffic congestion in communication networks, and the collapse of constructions. Here we propose the use of contrarians to suppress undesired synchronization. We perform a comparative study of different strategies, either requiring local or total knowledge of the system, and show that the most efficient one solely requires local information. Our results also reveal that, even when the distribution of neighboring interactions is narrow, significant improvement in mitigation is observed when contrarians sit at the highly connected elements. The same qualitative results are obtained for artificially generated networks as well as two real ones, namely, the Routers of the Internet and a neuronal network