bluuebunny/crossref_metadata_2025_split huggingface dataset:
Association between consumption of black tea and iron status in adult Africans in the North West Province: the THUSA study
Authors: Hogenkamp P. S. , Jerling J. C. , Hoekstra T. , Melse-Boonstra A. , MacIntyre U. E. 
Published: February 2008

The association between black tea consumption and iron status was investigated in a sample of African adults participating in the cross-sectional THUSA (Transition and Health during Urbanization of South Africans) study in the North West Province, South Africa. Data were analysed from 1605 apparently healthy adults aged 15–65 years by demographic and FFQ, anthropometric measurements and biochemical analyses. The main outcome measures were Hb and serum ferritin concentrations. No associations were seen between black tea consumption and concentrations of serum ferritin (menP = 0·059; womenP = 0·49) or Hb (menP = 0·33; womenP = 0·49). Logistic regression showed that tea consumption did not significantly increase risk for iron deficiency (men: OR 1·36; 95 % CI 0·99, 1·87; women: OR 0·98; 95 % CI 0·84, 1·13) nor for iron deficiency anaemia (men: OR 1·28; 95 % CI 0·84, 1·96; women: OR 0·93; 95 % CI 0·78, 1·11). Prevalence of iron deficiency and iron deficiency anaemia was especially high in women: 21·6 and 14·6 %, respectively. However, the likelihood of iron deficiency and iron deficiency anaemia was not significantly explained by tea consumption in sub-populations which were assumed to be at risk for iron deficiency. Regression of serum ferritin levels on tea consumption in women ≤ 40 years, adults with a daily iron intake ≤ 5·80 mg and adults with ferritin levels ≤ 26·60 μg/l, respectively, showedPvalues in the range of 0·28–0·88. Our findings demonstrate that iron deficiency and iron deficiency anaemia is not significantly explained by black tea consumption in a black adult population in South Africa. Tea intake was also not shown to be related to iron status in several sub-populations at risk for iron deficiency.
Prospective study on food fortification with vitamin D among adolescent females in Finland: minor effects
Authors: Lehtonen-Veromaa Marjo , Möttönen Timo , Leino Aila , Heinonen Olli J. , Rautava Essi , Viikari Jorma 
Published: February 2008

Vitamin D insufficiency is common particularly during wintertime. After the recommendation by the Ministry of Social Affairs and Health, Finnish fluid milks and margarines have been fortified with vitamin D since February 2003. The aims of the present study were to examine the impact of vitamin D fortification of food supplies on serum 25-hydroxyvitamin D (S-25(OH)D) concentrations and on daily dietary vitamin D intake among adolescent females. One hundred and forty-two girls of Caucasian ethnicity aged 12–18 years completed semi-quantitative FFQ from which the dietary vitamin D and Ca intakes were calculated. S-25(OH)D was measured by radioimmunoassay. The study was performed from February–March 2000 to February–March 2004, one year after the initiation of fortification. The mean dietary intake of vitamin D was < 7·5 μg in 91·5 % of the adolescent girls in 2000 and 83·8 % in 2004. The midwinter mean S-25(OH)D concentration did not change significantly during the follow-up period (48·3 v. 48·1 nmol/l, NS). The proportion of participants who had S-25(OH)D concentration < 50 nmol/l was 60·6 % in 2000 and 65·5 % in 2004. Only 7·0 % of the participants had an adequate S-25(OH)D ( ≥ 75 nmol/l) level in 2000 or 4 years later. The vitamin D fortification of fluid milks and margarines was inadequate to prevent vitamin D insufficiency. There are numerous adolescent girls and women who are not reached by the current fortification policy. Therefore new innovative and feasible ways of improving vitamin D nutrition are urged.
Influence of shell size ofLymnaea columellaon infectivity and development ofFasciola hepatica
Authors: Coelho L.H.L. , Guimarães M.P. , Lima W.S. 
Published: February 2008

AbstractExperimental infections ofLymnaea columellawithFasciola hepaticawere carried out to determine the influence of shell size on the infection rate and on the outcome of rediae and cercariae. Snails were divided into seven groups according to shell size: 2–4 mm, 5–6 mm, 7–8 mm, 9–10 mm, 11–12 mm, 13–14 mm and 15 mm or more. One hundred snails in each group were infected by using four miracidia for each snail. Snails with larger shell size showed a lower infection rate, the groups presenting the highest (79%) and lowest (2%) proportions of positives being those of 5–6 mm and 15 mm or more, respectively. Cercariae were present in 21% of them at 31 days post-infection, and cercarial shedding was observed 61 days post-infection. It was concluded that there is a non-linear negative association between shell size and infection rate.
The role of fear and anxiety in the familial risk for major depression: a three-generation study
Authors: Warner V. , Wickramaratne P. , Weissman M. M. 
Published: February 2008

BackgroundThe overlap between anxiety and major depressive disorder (MDD), the increased risk for depression and anxiety in offspring of depressed parents, the sequence of onset with anxiety preceding MDD, and anxiety as a predictor of depression are well established. The specificity of anxiety disorders in these relationships is unclear. This study, using a longitudinal high-risk design, examined whether anxiety disorders associated with the emotions fear and anxiety mediate the association between parental and offspring depression.MethodTwo hundred and twenty-four second-generation and 155 third-generation descendants at high and low risk for depression because of MDD in the first generation were interviewed over 20 years. Probit and Cox proportional hazard models were fitted with generation 2 (G2) or G3 depression as the outcome and parental MDD as the predictor. In G2 and G3, fear- (phobia or panic) and anxiety-related [overanxious or generalized anxiety disorder (GAD)] disorders were examined as potential mediators of increased risk for offspring depression, due to parental MDD.ResultsIn G2, fear-related disorders met criteria for mediating the association between parental MDD and offspring MDD whereas anxiety-related disorders did not. These results were consistent, regardless of the analytic methods used. Further investigation of the mediating effect of fear-related disorders by age of onset of offspring MDD suggests that the mediating effect occurs primarily in adolescent onset MDD. The results for G3 appear to follow similar patterns.ConclusionsThese findings support the separation of anxiety disorders into at least two distinct forms, particularly when examining their role in the etiology of depression.
Scenarios of diffusion and control of an influenza pandemic in Italy
Authors: RIZZO C. , LUNELLI A. , PUGLIESE A. , BELLA A. , MANFREDI P. , TOMBA G. SCALIA , IANNELLI M. , DEGLI ATTI M. L. CIOFI 
Published: February 2008

SUMMARYTo predict the spread of a pandemic strain of influenza virus in Italy and the impact of control measures, we developed a susceptible–exposed, but not yet infectious–infectious–recovered, and no longer susceptible (SEIR) deterministic model with a stochastic simulation component. We modelled the impact of control measures such as vaccination, antiviral prophylaxis and social distancing measures. In the absence of control measures, the epidemic peak would be reached about 4 months after the importation of the first cases in Italy, and the epidemic would last about 7 months. When combined, the control measures would reduce the cumulative attack rate to about 4·2%, at best, although this would require an extremely high number of treated individuals. In accordance with international findings, our results highlight the need to respond to a pandemic with a combination of control measures.
Red Halos of Galaxies – Reservoirs of Baryonic Dark Matter?
Authors: Zackrisson E. , Bergvall N. , Flynn C. , Östlin G. , Micheva G. , Caldwell B. 
Published: February 2008

AbstractDeep optical/near-IR surface photometry of galaxies outside the Local Group have revealed faint and very red halos around objects as diverse as disk galaxies and starbursting dwarf galaxies. The colours of these structures are too extreme to be reconciled with stellar populations similar to those seen in the stellar halos of the Milky Way or M31, and alternative explanations like dust reddening, high metallicities or nebular emission are also disfavoured. A stellar population obeying an extremely bottom-heavy initial mass function (IMF), is on the other hand consistent with all available data. Because of its high mass-to-light ratio, such a population would effectively behave as baryonic dark matter and could account for some of the baryons still missing in the low-redshift Universe. Here, we give an overview of current red halo detections, alternative explanations for the origin of the red colours and ongoing searches for red halos around types of galaxies for which this phenomenon has not yet been reported. A number of potential tests of the bottom-heavy IMF hypothesis are also discussed.
Lost Baryons at Low Redshift
Authors: Mathur Smita , Nicastro Fabrizio , Willimas Rik 
Published: February 2008

AbstractWe review our attempts to discover lost baryons at low redshift with the “X-ray forest” of absorption lines from the warm-hot intergalactic medium. We discuss the best evidence to date along the Mrk 421 sightline. We then discuss the missing baryons in the Local Group and the significance of the z = 0 absorption systems in X-ray spectra. We argue that the debate over the Galactic vs. extragalactic origin of the z = 0 systems is premature as these systems likely contain both components. Observations with next generation X-ray missions such as Constellation-X and XEUS will be crucial to map out the warm-hot intergalactic medium.
Observed Properties of Dark Matter on Small Spatial Scales
Authors: Wyse Rosemary F.G. , Gilmore Gerard 
Published: February 2008

AbstractThe nature of dark matter is one of the outstanding questions of astrophysics. The internal motions of member stars reveal that the lowest luminosity galaxies in the Local Group are the most dark-matter dominated. New large datasets allow one to go further, and determine systematic properties of their dark matter haloes. We summarise recent results, emphasising the critical role of the dwarf spheroidal galaxies in understanding both dark matter and baryonic processes that shape galaxy evolution.
Connecting Lost Baryons and Dark Galaxies via QSO Absorption Lines
Authors: Tripp Todd M. 
Published: February 2008

AbstractQSO absorption lines are sensitive to very low density gas, and consequently, QSO spectroscopy provides a powerful tool for measuring the distribution, physical conditions, and metal enrichment of baryons in the intergalactic medium and in “dark galaxies”. However, ultraviolet spectroscopy is required to study QSO absorbers in the nearby universe where the connections between the absorbing gas and galaxies/environment can be probed. This talk reviewed several recent studies of low-zQSO absorbers in order to demonstrate the value of combining high-resolution ultraviolet spectroscopy with complementary information on the absorber environment, e.g., mapping of 21 cm emission in the vicinity of the absorbers; some notes on these examples are presented in this paper. The absorbers probed range from high-N(H I) damped Lyman α absorbers down to very low-column Lyα forest clouds with logN(H I) < 13.5. The high-N(H I) systems are candidate “dark galaxies” – these systems are more metal enriched than the high-zIGM, possibly due to in-situ star formation, and some of the absorbers are highly metal enriched. However, we have obtained follow-up 21cm emission mapping with the VLA and deep optical imaging, and while we do find H I clouds associated with the absorbers in 21cm emission, we often do not find any evidence of in-situ stars. At this juncture, it seems more likely that these low-zabsorbers were enriched with metals within galaxies and were subsequently transported out into the IGM, e.g., by tidal stripping or galactic winds. This contribution also summarizes some recent results on the search for lost baryons in the “warm-hot” (shock-heated) low-redshift IGM.
ALFALFA: HI Cosmology in the Local Universe
Authors: Giovanelli Riccardo 
Published: February 2008

AbstractFor the last 25 years, the 21 cm line has been used productively to investigate the large–scale structure of the Universe, its peculiar velocity field and the measurement of cosmic parameters. In February 2005 a blind HI survey that will cover 7074 square degrees of the high latitude sky was started at Arecibo, using the 7-beam feed L-band feed array (ALFA). Known as the Arecibo Legacy Fast ALFA (ALFALFA) Survey, the program is producing a census of HI-bearing objects over a cosmologically significant volume of the local Universe. With respect to previous blind HI surveys, ALFALFA offers an improvement of about one order of magnitude in sensitivity, 4 times the angular resolution, 3 times the spectral resolution, and 1.6 times the total bandwidth of HIPASS. ALFALFA can detect 7×104D2M⊙of HI, whereDis the source distance in Mpc. As of mid 2007, 44% of the survey observations and 15% of the source extraction are completed. We discuss the status of the survey and present a few preliminary results, in particular with reference to the proposed “dark galaxy” VirgoHI21.
Cosmic Variance in the HI Mass Function
Authors: Schneider Stephen E. 
Published: February 2008

AbstractI review the history of blind HI surveys and the evidence for cosmic variance in the HI mass function. Even the most sensitive current surveys are challenged by noise levels that make determining the shape of the mass function difficult, and this can lead to discrepant results. However, some differences in the mass function appear to be real environmental effects, and this suggest that there are locales where dark (or dim) HI-rich galaxies are more likely to be found. The requirements for significantly deeper surveys beyond the local supercluster to sample cosmic variance in a wider variety of environoments are modeled and discussed.
The Arecibo Galaxy Environment Survey – Potential for finding Dark Galaxies and Results so far
Authors: Minchin R. F. , Auld R. , Cortese L. , Davies J. I. , Momjian E. , Taylor R. , Catinella B. , Henning P. , Linder S. , Muller E. , O'Neil K. , Rosenberg J. , Sabatini S. , Schneider S. E. , Stage M. , van Driel W. ,   the AGES team
Published: February 2008

AbstractThe Arecibo Galaxy Environment Survey is a blind neutral hydrogen survey using the ALFA multibeam receiver at Arecibo Observatory to reach unprecedented sensitivities in a number of selected fields in the local Universe. When completed the survey will cover 200 square degrees out to a distance of at least 270 Mpc. If a population of gas-rich dark galaxies exists, then this survey is in a prime position to uncover that population.So far 20 square degrees have been covered in the regions of Abell 1367, the Virgo Cluster, the NGC 7332/9 galaxy pair and the isolated galaxy NGC 1156. Over 200 sources have been found, including a number that have no obvious optical counterparts. We discuss here the potential of AGES for uncovering more such objects and the characteristics of the dark sources identified to date.
Free–Floating HI Clouds in the M 81 Group
Authors: Brinks Elias , Walter Fabian , Skillman Evan D. 
Published: February 2008

AbstractRecent VLA observations pointed at dwarf spheroidal (dSph) galaxies in the M 81 group reveal a hitherto hidden population of extremely low mass (~ 105 M⊙) HI clouds with no obvious optical counterparts. We have searched 10 fields in the M 81 group totalling 2.2 square degree, both targeting known dwarf spheroidal galaxies and blank fields around the central triplet. Our observations show that the new population of low–mass HI clouds appears to be confined to a region toward the south–east of the central triplet (at distances of ~ 100 kpc from M 81). Possible explanations for these free–floating HI clouds are that they are related to the dSphs found to the South–East of M 81, that they belong to the galaxies of the M 81 triplet (equivalent to HVCs), that they are of primordial nature and provide fresh, unenriched material falling into the M 81 group, or that they are tidal debris from the 3–body interaction involving M 81–M 82–NGC 3077. Based on circumstantial evidence, we currently favour the latter explanation.
The Halo by Halo Missing Baryon Problem
Authors: McGaugh Stacy S. 
Published: February 2008

AbstractThe global missing baryon problem – that the sum of observed baryons falls short of the number expected form BBN – is well known. In addition to this, there is also a local missing baryon problem that applies to individual dark matter halos. This halo by halo missing baryon problem is such that the observed mass fraction of baryons in individual galaxies falls short of the cosmic baryon fraction. This deficit is a strong function of circular velocity. I give an empirical estimate of this function, and note the presence of a critical scale of ~ 900 km s−1 therein. I also briefly review Ωb from BBN, highlighting the persistent tension between lithium and the CMB, and discuss some pros and cons of individual galaxies and clusters of galaxies as potential reservoirs of dark baryons.
The Local Void is Really Empty
Authors: Tully R. Brent 
Published: February 2008

AbstractAre voids in the distribution of galaxies only places with reduced matter density and low star formation efficiency or are they empty of matter? There is now compelling evidence of expansion away from the Local Void at very high velocities. The motion is most reasonably interpreted as an evacuation of the void, which requires that the void be very large and very empty.
Dim Baryons in the Cosmic Web
Authors: Impey Chris D. 
Published: February 2008

AbstractThe distribution of baryons beyond galaxies is descibed. The majority of the baryons, which represent 4% of the cosmic mass and energy budget, lie far from individual galaxies in the diffuse intergalactic medium (IGM). Many of these baryons are in a warm phase that can be probed by quasar absorption in the Lyman-α line of hydrogen. The mature field of quasar spectroscopy can diagnose the location, physical state, metallicity, and general geometry of this gas, which is called the “cosmic web.” The remainder of the gas is kept very hot by infall and shocks and is mostly in higher density regions such as filaments, groups and clusters. The hot gas is only detectable via X-rays and the absorption of highly ionized species of heavy elements. The baryons in low density regions of space are excellent tracers of underlying dark matter. The evolution of the cosmic web indicates where to look for the baryons in collapsed objects but the overall inefficiency of galaxy formation has conspired to keep most baryons dark.
A Census of Baryons in Galaxy Clusters and Groups
Authors: Gonzalez Anthony H. , Zaritsky Dennis , Zabludoff Ann I. 
Published: February 2008

AbstractWhile the baryon fraction in galaxy groups and clusters may be expected to reflect the universal value, observations of cluster baryon fractions have generally fallen short of this expectation and indicated a possible correlation with cluster mass. We present a new determination of the total baryon budget in nearby galaxy groups and clusters that includes the contributions from stars in galaxies, intracluster stars, and the intracluster medium. We find that the baryon mass fraction within r500 is independent of system mass and lower than the WMAP value. We conclude however that the present shortfall provides no compelling evidence for additional missing baryons, since it may arise due to a theoretically predicted deficit of baryons within r500 and systematic uncertainties associated with the mass determinations. With the addition of the ICL to the stellar mass in galaxies, the increase in X-ray gas mass fraction with increasing total mass is entirely accounted for by a decrease in the total stellar mass fraction, supporting the argument that the behavior of both the stellar and X-ray gas components is dominated by a decrease in star formation efficiency in more massive environments. Within just the stellar component, the fraction of the total stellar luminosity in the central, giant brightest cluster galaxy (BCG) and ICL (hereafter the BCG+ICL component) decreases as velocity dispersion (σ) increases, suggesting that ICL may grow less efficiently in higher mass environments. The identification of low mass groups with large BCG+ICL components also demonstrates that the massive cluster environment is not required to form intracluster stars. These proceedings are a condensed version of the work presented in Gonzalez, Zaritsky & Zabludoff (2007), and we refer the reader to that paper for a more complete discussion.
Statistical Properties of the IntraCluster Light from SDSS Image Stacking
Authors: Zibetti Stefano 
Published: February 2008

AbstractThe presence of a diffuse stellar component in galaxy clusters has been established by a number of observational works in recent years. In this contribution I summarize our results (Zibettiet al. 2005) obtained by stacking SDSS images of 683 clusters, selected with the maxBCG algorithm at 0.2 <z< 0.3. Thanks to our large sample (≳30 times larger than any other sample of individually observed clusters so far) and the advantages of image stacking applied to SDSS images, we are able to measure thesystematicproperties of the intracluster light (ICL) with very high accuracy.We find that the average surface brightness of the ICL ranges between 26 and 32 mag arcsec−2, and constantly declines from 70 kpc cluster-centric distance (i.e. distance from the BCG) to 700 kpc. Interestingly, thefractionof diffuse light over the total light (including galaxies), monotonically declines from ~ 50 to ≲ 5% over the same range of distances, thus showing that the ICL is more easily produced close to the bottom of a cluster's potential well. On the other hand, clusters lacking a bright BCG, hardly build up a large amount of intracluster stellar component. The link between the growth of the BCG and the ICL is also suggested by the strong degree of alignment between these two components which is observed in clusters where the BCG displays a significant elongation. With the additional fact that the colors of the ICL are consistent with those of galaxies, all this appears to be evidence for intracluster stars being stripped from galaxies that suffer very strong tidal interactions in the center of clusters and eventually merge into the BCG.Our measurements also show that intracluster stars are a minor component of a cluster's baryonic budget, representing only ~ 10% of the total optical emission within 500 kpc.Finally, we discuss some open issues that emerge from a comparison of the present results with other observations and recent theoretical modeling.
Star Formation Thresholds
Authors: Schaye Joop 
Published: February 2008

AbstractTo make predictions for the existence of “dark galaxies”, it is necessary to understand what determines whether a gas cloud will form stars. Star formation thresholds are generally explained in terms of the Toomre criterion for gravitational instability. I contrast this theory with the thermo-gravitational instability hypothesis of Schaye (2004), in which star formation is triggered by the formation of a cold gas phase and which predicts a nearly constant surface density threshold. I argue that although the Toomre analysis is useful for the global stability of disc galaxies, it relies on assumptions that break down in the outer regions, where star formation thresholds are observed. The thermo-gravitational instability hypothesis can account for a number of observed phenomena, some of which were thought to be unrelated to star formation thresholds.