A Spitzer IRAC Census of the Asymptotic Giant Branch Populations in Local Group Dwarfs. II. IC 1613

We present Spitzer Space Telescope IRAC photometry of the Local Group dwarf irregular galaxy IC 1613. We compare our 3.6, 4.5, 5.8, and 8.0 micron photometry with broadband optical photometry and find that the optical data do not detect 43% and misidentify an additional 11% of the total AGB population, likely because of extinction caused by circumstellar material. Further, we find that a narrowband optical carbon star study of IC 1613 detects 50% of the total AGB population and only considers 18% of this population in calculating the carbon to M-type AGB ratio. We derive an integrated mass-loss rate from the AGB stars of 0.2-1.0 x 10^(-3) solar masses per year and find that the distribution of bolometric luminosities and mass-loss rates are consistent with those for other nearby metal-poor galaxies. Both the optical completeness fractions and mass-loss rates in IC 1613 are very similar to those in the Local Group dwarf irregular, WLM, which is expected given their similar characteristics and evolutionary histories.Comment: Accepted by ApJ, 26 pages, 10 figures, version with high-resolution figures available at: http://webusers.astro.umn.edu/~djackson

Galaxy Populations and Evolution in Clusters IV: Deep HI Observations of Dwarf Ellipticals in the Virgo Cluster

We present in this paper the deepest Arecibo HI observations of Virgo cluster dwarf ellipticals (dEs) taken to date. Based on this data we argue that a significant fraction of Virgo cluster dEs recently underwent evolution. Our new observations consist of HI 21-cm line observations for 22 classified dE galaxies with optical radial velocities consistent with membership in the Virgo cluster. Cluster members VCC 390 and VCC 1713 are detected with HI masses M(HI) = 6*10^7 M_solar and 8*10^7 M_solar, respectively, while M(HI) in the remaining 20 dE galaxies have upper limits as low as 5*10^5 M_solar. We combine our results with those for 27 other Virgo cluster dEs with HI observations in the literature, 7 of which have HI detection claims. New optical images from the WIYN telescope of 5 of these HI-detected dEs, along with archival data, suggest that seven of the claimed detections are real, yielding a ~ 15% detection rate. These HI-detected classified dEs are preferentially located near the periphery of the Virgo cluster. Three Virgo dEs have observed HI velocity widths > 200 km/s, possibly indicating the presence of a large dark matter content, or transient extended HI. We discuss the possible origins of these objects and argue that they originate from field galaxies accreted onto high angular momentum orbits by Virgo in the last few Gyr. As a result these galaxies are slowly transformed within the cluster by gradual gas stripping processes, associated truncation of star formation, and passive fading of stellar populations. Low-mass early-type cluster galaxies are therefore currently being produced as the product of cluster environmental effects. We utilize our results to estimate the recent (past 1-3 Gyr) average mass accretion rate into the Virgo cluster, finding dM/dt ~ 50 M_solar/year.Comment: Accepted to ApJ, 21 page

Rotation Curves of Spiral Galaxies

Rotation curves of spiral galaxies are the major tool for determining the distribution of mass in spiral galaxies. They provide fundamental information for understanding the dynamics, evolution and formation of spiral galaxies. We describe various methods to derive rotation curves, and review the results obtained. We discuss the basic characteristics of observed rotation curves in relation to various galaxy properties, such as Hubble type, structure, activity, and environment.Comment: 40 pages, 6 gif figures; Ann. Rev. Astron. Astrophys. Vol. 39, p.137, 200

The Netherlands Arrhythmogenic Cardiomyopathy Registry:design and status update

BACKGROUND: Clinical research on arrhythmogenic cardiomyopathy (ACM) is typically limited by small patient numbers, retrospective study designs, and inconsistent definitions. AIM: To create a large national ACM patient cohort with a vast amount of uniformly collected high-quality data that is readily available for future research. METHODS: This is a multicentre, longitudinal, observational cohort study that includes (1) patients with a definite ACM diagnosis, (2) at-risk relatives of ACM patients, and (3) ACM-associated mutation carriers. At baseline and every follow-up visit, a medical history as well information regarding (non-)invasive tests is collected (e. g. electrocardiograms, Holter recordings, imaging and electrophysiological studies, pathology reports, etc.). Outcome data include (non-)sustained ventricular and atrial arrhythmias, heart failure, and (cardiac) death. Data are collected on a research electronic data capture (REDCap) platform in which every participating centre has its own restricted data access group, thus empowering local studies while facilitating data sharing. DISCUSSION: The Netherlands ACM Registry is a national observational cohort study of ACM patients and relatives. Prospective and retrospective data are obtained at multiple time points, enabling both cross-sectional and longitudinal research in a hypothesis-generating approach that extends beyond one specific research question. In so doing, this registry aims to (1) increase the scientific knowledge base on disease mechanisms, genetics, and novel diagnostic and treatment strategies of ACM; and (2) provide education for physicians and patients concerning ACM, e. g. through our website ( www.acmregistry.nl ) and patient conferences

Normal and Cut-Off Values of the Cytokinesis-Block Micronucleus Assay on Peripheral Blood Lymphocytes in the Croatian General Population

Mikronukleus (MN) test na limfocitima periferne krvi jedna je od najvažnijih metoda koje se primjenjuju u citogenetičkom nadzoru. Osnovni preduvjet za primjenu nekog testa u svrhu nadzora profesionalno izloženih populacija jest poznavanje normalnih vrijednosti promatranoga biološkog pokazatelja (biomarkera) u kontrolnoj populaciji. Baze podataka na razini opće populacije moraju se redovito obnavljati novim podacima. Cilj ovog istraživanja bio je utvrditi normalne i granične vrijednosti MN-testa na limfocitima periferne krvi 200 zdravih ispitanika obaju spolova iz opće populacije Republike Hrvatske te ispitati koji čimbenici pridonose spontanom nastanku MN. Na razini istražene populacije utvrđeno je prosječno (6,90±3,32) MN (medijan 7 MN), dok je raspon pojedinačnih vrijednosti iznosio 0 do 18 MN u 1000 binuklearnih stanica. Gornja granična vrijednost dobivena izračunavanjem 95. percentila za cjelokupnu promatranu populaciju iznosi 12,5 MN na 1000 limfocita. Utvrđeno je da na spontani nastanak MN utječu spol, dob i navika pušenja. Žene u prosjeku imaju više vrijednosti svih parametara MN-testa od muškaraca, a u njih je bio i naglašeniji porast vrijednosti citogenetičkog nalaza zbog navike pušenja. Kako su literaturni podaci o utjecaju pušenja cigareta na nastanak MN kontradiktorni, planiran je nastavak istraživanja radi razjašnjavanja utjecaja dnevno utrošenog broja cigareta i ukupnog trajanja pušačkog staža na vrijednosti parametara MN-testa. Usporedba rezultata s literaturnim podacima potvrdila je da su dobivene vrijednosti u skladu s vrijednostima MN-testa zabilježenim na općoj populaciji u drugim svjetskim laboratorijima. Normalne i granične vrijednosti MN-testa utvrđene u ovome istraživanju poslužit će kao osnova za usporedbu i tumačenje nalaza MN-testa u ispitanika izloženih populacija te daljnju nadogradnju laboratorijske baze podataka.The cytokinesis-block micronucleus (CBMN) assay on peripheral blood lymphocytes is one of the most important methods employed in cytogenetic biomonitoring. For the purposes of biological dosimetry, it is important to kno the spontaneous frequency of a biomarker and its normal values in general population. These values are used for population databases, which should be updated regularly. In this study, MN levels were investigated in cytokinesis-blocked lymphocytes of 200 healthy male and female blood donors selected at random from the general population of Croatia. The aim was to assess the variability and determine possible infl uences of external and/or internal factors on the background levels of MN and to establish the cut-off value for the CBMN assay. The background frequency of MN was (6.90±3.32) MN (median 7 MN) and the range was 0 to 18 MN per 1000 binuclear lymphocytes. The cut-off value, which corresponds to 95th percentile of the distribution of 200 individual values, was 12.5 MN. Spontaneous formation of MN was infl uenced by sex, age, and smoking. Women had higher MN levels than men. However, only age and smoking signifi cantly increased the values of all parameters evaluated by the CBMN assay. Since the existing literature data on smoking-related formation of MN are contradictory, we will continue these investigations to resolve how the number of cigarettes smoked per day and the duration of smoking in years infl uence the results of the CBMN assay. Our results are consistent with the background MN frequencies reported by other cytogenetic laboratories worldwide. Normal and cut-off values estimated in this study will be used to update the current general population data and as reference for occupationally or accidental exposure

Kavezno izlaganje lubina (Dicentrarchus labrax) u procjeni genotoksičnog utjecaja onečišćenja

Genotoxic effects are often the earliest signs of pollution-related environmental disturbance. In this study, we used the comet assay and micronucleus test to assess DNA damage in the erythrocytes of the European sea bass (Dicentrarchus labrax) exposed to environmental pollution in situ. Fish were collected from a fi sh farm in the Trogir Bay and their cages placed at an unpolluted reference site Šolta (Nečujam Bay) and a polluted site Vranjic (Kaštela Bay) for four weeks. A group of fi sh which remained at the fi sh farm Trogir Bay were used as the second control group. Fish exposed at the Vranjic site showed a signifi cantly higher erythrocyte DNA damage, measured by the comet assay, than either control group. Micronucleus induction showed a similar gradient of DNA damage, but did not reach statistical signifi cance. Our results show that cage exposure of a marine fi sh D. labrax can be useful in environmental biomonitoring and confi rm the comet assay as a suitable tool for detecting pollution-related genotoxicity.Genotoksični učinak često je jedan od najranijih pokazatelja štetnog djelovanja onečišćenja okoliša. U ovom radu procijenjeno je oštećenje DNA u eritrocitima lubina (Dicentrarchus labrax) izloženima okolišnom onečišćenju s pomoću komet-testa i mikronukleus-testa. Lubini su prikupljeni na ribogojilištu i kavezno izloženi u periodu od četiri tjedna na dvije postaje različitog stupnja onečišćenja na jadranskoj obali: na kontrolnoj postaji Šolta (zaljev Nečujam) i na onečišćenoj postaji Vranjic (Kaštelanski zaljev). Zasebna skupina lubina skupljena na ribogojilištu poslužila je kao druga kontrola. Rezultati komet-testa pokazali su statistički značajan porast oštećenja DNA na postaji Vranjic u usporedbi s obje kontrolne postaje. Rezultati mikronukleus-testa pokazali su sličan gradijent onečišćenja, iako nisu dosegli statističku značajnost. Ovi rezultati upućuju na primjenjivost kaveznog izlaganja lubina D. labrax u biomonitoringu vodenog okoliša te potvrđuju korisnost komet-testa kao prikladne metode za detekciju genotoksičnog utjecaja onečišćenja

Biomonitoring of complex occupational exposures to carcinogens: The case of sewage workers in Paris

<p>Abstract</p> <p>Background</p> <p>Sewage workers provide an essential service in the protection of public and environmental health. However, they are exposed to varied mixtures of chemicals; some are known or suspected to be genotoxics or carcinogens. Thus, trying to relate adverse outcomes to single toxicant is inappropriate. We aim to investigate if sewage workers are at increased carcinogenic risk as evaluated by biomarkers of exposure and early biological effects.</p> <p>Methods/design</p> <p>This cross sectional study will compare exposed sewage workers to non-exposed office workers. Both are voluntaries from Paris municipality, males, aged (20–60) years, non-smokers since at least six months, with no history of chronic or recent illness, and have similar socioeconomic status. After at least 3 days of consecutive work, blood sample and a 24-hour urine will be collected. A caffeine test will be performed, by administering coffee and collecting urines three hours after. Subjects will fill in self-administered questionnaires; one covering the professional and lifestyle habits while the a second one is alimentary. The blood sample will be used to assess DNA adducts in peripheral lymphocytes. The 24-hour urine to assess urinary 8-oxo-7, 8-dihydro-2'-deoxy-Guanosine (8-oxo-dG), and the in vitro genotoxicity tests (comet and micronucleus) using HeLa S3 or HepG2 cells. In parallel, occupational air sampling will be conducted for some Polycyclic Aromatic Hydrocarbons and Volatile Organic Compounds. A weekly sampling chronology at the offices of occupational medicine in Paris city during the regular medical visits will be followed. This protocol has been accepted by the French Est III Ethical Comitee with the number 2007-A00685-48.</p> <p>Discussion</p> <p>Biomarkers of exposure and of early biological effects may help overcome the limitations of environmental exposure assessment in very complex occupational or environmental settings.</p

Genome-wide association analyses identify new Brugada syndrome risk loci and highlight a new mechanism of sodium channel regulation in disease susceptibility

Brugada syndrome (BrS) is a cardiac arrhythmia disorder associated with sudden death in young adults. With the exception of SCN5A, encoding the cardiac sodium channel NaV1.5, susceptibility genes remain largely unknown. Here we performed a genome-wide association meta-analysis comprising 2,820 unrelated cases with BrS and 10,001 controls, and identified 21 association signals at 12 loci (10 new). Single nucleotide polymorphism (SNP)-heritability estimates indicate a strong polygenic influence. Polygenic risk score analyses based on the 21 susceptibility variants demonstrate varying cumulative contribution of common risk alleles among different patient subgroups, as well as genetic associations with cardiac electrical traits and disorders in the general population. The predominance of cardiac transcription factor loci indicates that transcriptional regulation is a key feature of BrS pathogenesis. Furthermore, functional studies conducted on MAPRE2, encoding the microtubule plus-end binding protein EB2, point to microtubule-related trafficking effects on NaV1.5 expression as a new underlying molecular mechanism. Taken together, these findings broaden our understanding of the genetic architecture of BrS and provide new insights into its molecular underpinnings

RNAcentral 2021: secondary structure integration, improved sequence search and new member databases

RNAcentral is a comprehensive database of non-coding RNA (ncRNA) sequences that provides a single access point to 44 RNA resources and >18 million ncRNA sequences from a wide range of organisms and RNA types. RNAcentral now also includes secondary (2D) structure information for >13 million sequences, making RNAcentral the world’s largest RNA 2D structure database. The 2D diagrams are displayed using R2DT, a new 2D structure visualization method that uses consistent, reproducible and recognizable layouts for related RNAs. The sequence similarity search has been updated with a faster interface featuring facets for filtering search results by RNA type, organism, source database or any keyword. This sequence search tool is available as a reusable web component, and has been integrated into several RNAcentral member databases, including Rfam, miRBase and snoDB. To allow for a more fine-grained assignment of RNA types and subtypes, all RNAcentral sequences have been annotated with Sequence Ontology terms. The RNAcentral database continues to grow and provide a central data resource for the RNA community. RNAcentral is freely available at https://rnacentral.org