bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chest radiograph thoracic areas and lung volumes in infants developing bronchopulmonary dysplasia
Authors: May Caroline , Prendergast Michael , Salman Saba , Rafferty Gerrard F. , Greenough Anne 
Published: December 2008

AbstractObjectivesTo determine whether chest radiograph (CXR) thoracic areas and lung volumes differed between infants who did and did not develop BPD and according to the severity of BPD developed.Working HypothesisInfants developing BPD, particularly if moderate or severe, would have low CXR thoracic areas and lung volumes in the perinatal period.Study DesignProspective study.Patient‐Subject Selection53 infants with a median gestational age of 28 (range 24–32) weeks.MethodologyCXR thoracic areas were calculated using a Picture Archiving and Communicating System (PACS) and lung volume assessed by measurement of functional residual capacity (FRC) in the first 72 hr after birth. BPD was diagnosed if the infants were oxygen dependent beyond 28 days, mild BPD in infants no longer oxygen dependent at 36 weeks post‐menstrual age (PMA) and moderate/severe BPD in infants who required supplementary oxygen with or without respiratory support at 36 weeks PMA.ResultsThirty two infants developed BPD, 21 had moderate/severe BPD. The median CXR thoracic areas were higher (P < 0.0001) and FRCs were lower (P < 0.0001) in the BPD compared to no BPD infants. The median CXR thoracic areas of the moderate/severe group (P < 0.001) and the mild group (P < 0.05) were greater than that of the no BPD group and the median FRC of the moderate/severe BPD group was lower than the no BPD group (<0.001) and the mild BPD group (P < 0.05).ConclusionThese results highlight that in the perinatal period infants developing BPD, particularly if moderate/severe, have low functional lung volumes and may have gas trapping, which likely reflects ventilation inhomogeneity. Pediatr Pulmonol. 2009; 44:80–85. © 2008 Wiley‐Liss, Inc.
Comparison of the components of the planktonic food web in three large rivers (Rhine, Moselle and Saar)
Authors: Bergfeld Tanja , Scherwass Anja , Ackermann Barbara , Arndt Hartmut , Schöl Andreas 
Published: December 2008

AbstractThe dynamics of phyto‐, bacterio‐, proto‐ and metazooplankton were investigated for a period of 22 months fortnightly from March 1999 until December 2000 in the rivers Moselle, Saar and Rhine. Plankton abundances reached the lowest values in the Rhine and the highest in the Saar. Protozoa and not the much more studied metazoa clearly dominate the zooplankton not only by number but also by biomass by about 90%. We show that the plankton biomass in each of the rivers is the result of the interplay of the grazing by benthic predators and of the human induced factors such as river morphology, water residence time and nutrient load. Furthermore, we compare our study with the planktonic food web of three other large European rivers. The comparison between all studies revealed a general rise of the absolute mean biomass of all heterotrophic planktonic food web components (bacteria, protozoa, metazoa) parallel to an increase of the algal biomass of the river. For the rivers Rhine, Moselle and Saar, the average biomass of all investigated plankton groups was very low compared to the values obtained in the rivers Meuse, Loire and Elbe. The relative importance of organisms of the microbial food web increased with a decrease of the algal biomass or organic carbon content, respectively, in each of the rivers. We postulate that with a sinking nutrient level in the Rhine, the microbial food web components will become even more important within the plankton than they already are. Copyright © 2008 John Wiley & Sons, Ltd.
Spatial and seasonal variations in δ13C AND δ15N of particulate organic matter in a dam‐controlled subtropical river
Authors: Chen Fajin , Jia Guodong 
Published: December 2008

AbstractAlteration of stream flow by artificial dams has been observed to be a significant factor for river water environmental changes. Therefore, understanding the biogeochemical processes occurring in the dam‐controlled rivers is important for water resource management. In this paper, δ13C and δ15N signatures of particulate organic matter (POM) in a dam‐controlled subtropical river, Beijiang River, in south China are reported for their spatial and seasonal distributions. POM affected by reservoirs is lighter in δ13C and heavier in δ15N relative to unaffected POM. In April, POM δ13C and δ15N values show less spatial variation in the mainstem, and suggest relatively greater contributions of terrestrial organic matter (OM) to POM. This could be related to the onset of summer monsoon that caused an abrupt increase in terrestrial input to the river by the monsoon‐induced enhancement of rainfall and runoff. In August and December, however, POM isotopic values for the sites affected by the Feilaixia dam reservoir in the middle of the river show marked changes, suggesting aquatic plankton proliferation in the reservoir during the times. Upstream from the reservoirs, POM isotopes are seasonally less varied and suggest mainly terrestrial origin. However, the isotopic signals of aquatic plankton proliferation in the reservoir in August and December is imprinted on the POM isotopic compositions downstream the reservoir, indicating far‐reaching influences of the reservoir on the downstream water environment. Copyright © 2008 John Wiley & Sons, Ltd.
Discontinuous DBH–height relationship of Cryptomeria japonica on Yakushima Island: effect of frequent typhoons on the maximum height
Authors: Takashima Atsushi , Kume Atsushi , Yoshida Shigejiro , Murakami Takuhiko , Kajisa Tsuyoshi , Mizoue Nobuya 
Published: December 2008

AbstractThe mountain zone of Yakushima Island is covered with a mixed conifer‐broadleaved forest dominated by old‐growth Cryptomeria japonica (L.f.) D. Don trees. Even though Yakushima Island has been frequently struck by typhoons with wind velocities exceeding 55 m s−1, the Cr. japonica trees in the mountain zone have survived for thousands of years without fatal damage. To evaluate the effect of storms on tree growth, the relationships between the stem diameter at breast height (DBH) and the heights of Cr. japonica and coexistent tree species were investigated. Two models based on an expanded allometric equation and a discontinuous piecewise allometric equation, respectively, to represent DBH–height relationships were evaluated. In all plots, the DBH–height relationship of Cr. japonica was discontinuous between small DBH and large DBH individuals. The tops of the large DBH individuals of Cr. japonica were lost to strong winds. However in each instance, they occupied the highest position in the canopy, even if they had lost their tops. In contrast, the DBH–height relationships of subcanopy broadleaved species were continuous in many plots and the equilibrium heights of the dominant broadleaved species were similar and almost in the same order regardless of the canopy heights of Cr. japonica. These results revealed a constant vertical structure in the Cr. japonica forest on Yakushima Island. Our results demonstrate a vertical niche segregation in the forest under high wind pressures and such vertical structure enables effective use of forest space and increases the basal area density.
Comparison of Surface‐Active Properties of (Alkyloxycarbonylmethyl)trimethylammonium Chlorides and Alkyltrimethylammonium Chlorides
Authors: Itoh Yoshihiro , Akasaka Ryo 
Published: December 2008

AbstractSurface‐active properties of cleavable surfactants with a betaine ester group—(n‐alkyloxycarbonylmethyl)trimethylammonium chlorides, used as separation reagents—were investigated. Critical micelle concentrations, dispersing powers, and foaming powers were comparable to those of alkyltrimethylammonium chlorides with the same total number of carbon atoms. On the other hand, the solubilities of the four hydrophobic dyes N,N‐dimethyl‐3‐nitroaniline, naphthalene, pyrene, and oil orange SS in the former surfactant solutions were equal to or slightly smaller than those in the solutions of the latter surfactants with the same alkyl chain length. The alkali hydrolysis yields of the formers approached 100% in aqueous buffer solution at pH 10 and 25 °C within 10 min, and the yield at pH 9 was dependent on the alkyl chain length. This type of surfactant was also found to be as an efficient separation reagent which disperses carbon black and solubilizes the above dyes into aqueous neutral solution and then separates them instantaneously and almost perfectly as precipitates when a small excess of NaOH is added.
Separate groups of dorsal horn neurons transmit spontaneous activity and mechanosensitivity one day after plantar incision
Authors: Xu Jun , Richebe Philippe , Brennan Timothy J. 
Published: December 2008

ABSTRACTDorsal horn neuron (DHN) sensitization can be induced and maintained by nociceptor activation. In previous studies, only a small increase in ongoing DHN activity was present immediately after plantar incision; yet, powerful activation of nociceptors was prominent 1 day after incision. In the present study, rats underwent plantar incision or sham surgery as control. One day later pain behaviors were measured; then DHN activity and response properties to mechanical stimulation were recorded in vivo. In some neurons with spontaneous activity, the incision was anesthetised using bupivacaine. Spontaneous activity was identified in 9 of 27 neurons in the control group and in 16 of 26 neurons (P<0.05) in the incision group; the spontaneous activity in incised animals (19.1±8.5 imp/s) was also greater than in controls (10.6±6.1 imp/s, P<0.05). For neurons without spontaneous activity, the responses to mechanical stimuli of the incision group were greater (P<0.01); for neurons with spontaneous activity, there was no such difference. After bupivacaine injection, no difference was present in the amount of spontaneous activity between the two groups. This study demonstrates that 1 day after incision, DHN sensitization manifests in markedly increased spontaneous activities, enhanced responses to mechanical stimuli and expanded receptive fields (RFs). Separate groups of neurons appear to transmit spontaneous activity and enhanced responses to mechanical stimuli. Inhibition of spontaneous activity by blockade of afferent input indicates that the prolonged spinal hyperactivity remains largely dependent on the ongoing primary afferent activity.
ISOMETRIES AND DISCRETE ISOMETRY SUBGROUPS OF HYPERBOLIC SPACES
Authors: FU XI , WANG XIANTAO 
Published: December 2008

AbstractLet n be the n-dimensional hyperbolic space with n ≥ 2. Suppose that G is a discrete, sense-preserving subgroup of Isomn, the isometry group of n. Let p be the projection map from n to the quotient space M = n/G. The first goal of this paper is to prove that for any a ∈ ∂n (the sphere at infinity of n), there exists an open neighbourhood U of a in n ∪ ∂ n such that p is an isometry on U ∩ n if and only if a ∈ oΩ(G) (the domain of proper discontinuity of G). This is a generalization of the main result discussed in the work by Y. D. Kim (A theorem on discrete, torsion free subgroups of Isomn, Geometriae Dedicata109 (2004), 51–57). The second goal is to obtain a new characterization for the elements of Isomn by using a class of hyperbolic geometric objects: hyperbolic isosceles right triangles. The proof is based on a geometric approach.
GLOBAL EXISTENCE AND BLOW-UP FOR NON-NEWTON POLYTROPIC FILTRATION SYSTEM COUPLED WITH LOCAL SOURCE
Authors: ZHOU JUN , MU CHUNLAI 
Published: December 2008

AbstractThis paper deals with the global existence and blow-up properties of the following non-Newton polytropic filtration system coupled with local source:ut− Δm,pu=avα,vt− Δn,qv=buβ. Under appropriate hypotheses, we prove that the solution either exists globally or blows up in finite time depending on the initial data and the relations between αβ andmn(p− 1)(q− 1).
ON LITTLEWOOD-PALEY FUNCTIONS ASSOCIATED WITH BESSEL OPERATORS
Authors: BETANCOR J. J. , FARIÑA J. C. , SANABRIA A. 
Published: December 2008

AbstractIn this paper, we study Lp-boundedness properties for higher order Littlewood-Paley g-functions in the Bessel setting. We use the Calderón-Zygmund theory in a homogeneous-type space (in the sense of Coifman and Weiss) ((0, ∞), d, γα), where d represents the usual metric on (0, ∞) and γα denotes the doubling measure on (0, ∞) with respect to d defined by dγα(x) = x2α+1dx, with α > −1/2.
SPECTRUM, NUMERICAL RANGE AND DAVIS-WIELANDT SHELL OF A NORMAL OPERATOR
Authors: LI CHI-KWONG , POON YIU-TUNG 
Published: December 2008

AbstractWe denote the numerical range of the normal operator T by W(T). A characterization is given to the points in W(T) that lie on the boundary. The collection of such boundary points together with the interior of the the convex hull of the spectrum of T will then be the set W(T). Moreover, it is shown that such boundary points reveal a lot of information about the normal operator. For instance, such a boundary point always associates with an invariant (reducing) subspace of the normal operator. It follows that a normal operator acting on a separable Hilbert space cannot have a closed strictly convex set as its numerical range. Similar results are obtained for the Davis-Wielandt shell of a normal operator. One can deduce additional information of the normal operator by studying the boundary of its Davis-Wielandt shell. Further extension of the result to the joint numerical range of commuting operators is discussed.
NOTE ON THE DIVISIBILITY OF THE CLASS NUMBER OF CERTAIN IMAGINARY QUADRATIC FIELDS
Authors: KISHI YASUHIRO 
Published: December 2008

AbstractWe prove that the class number of the imaginary quadratic field $\Q(\sqrt{2^{2k}-3^n})$ is divisible by n for any positive integers k and n with 22k < 3n, by using Y. Bugeaud and T. N. Shorey's result on Diophantine equations.
The inter-relationship between formal and informal care: a study in France and Israel
Authors: LITWIN HOWARD , ATTIAS-DONFUT CLAUDINE 
Published: December 2008

ABSTRACTThis study examined whether formal care services delivered to frail older people's homes in France and Israel substitute for or complement informal support. The two countries have comparable family welfare systems but many historical, cultural and religious differences. Data for the respondents aged 75 or more years at the first wave of the Survey of Health, Ageing and Retirement in Europe (SHARE) were analysed. Regressions were examined of three patterns of care fromoutsidethe household: informal support only, formal support only and both formal and informal care, with the predictor variables including whether informal help was provided by a family member living in the household. The results revealed that about one-half of the respondents received no help at all (France 51%, Israel 55%), about one-tenth received care from a household member (France 8%, Israel 10%), and one-third were helped by informal carers from outside the household (France 34%, Israel 33%). More French respondents (35%) received formal care services at home than Israelis (27%). Most predictors of the care patterns were similar in the two countries. The analysis showed that complementarity is a common outcome of the co-existence of formal and informal care, and that mixed provision occurs more frequently in situations of greater need. It is also shown that spouse care-givers had less formal home-care supports than either co-resident children or other family care-givers. Even so, spouses, children and other family care-givers all had considerable support from formal home-delivered care.
Open questions in the study of population III star formation
Authors: Glover S. C. O. , Clark P. C. , Greif T. H. , Johnson J. L. , Bromm V. , Klessen R. S. , Stacy A. 
Published: December 2008

AbstractThe first stars were key drivers of early cosmic evolution. We review the main physical elements of the current consensus view, positing that the first stars were predominantly very massive. We continue with a discussion of important open questions that confront the standard model. Among them are uncertainties in the atomic and molecular physics of the hydrogen and helium gas, the multiplicity of stars that form in minihalos, and the possible existence of two separate modes of metal-free star formation.
The formation of the first galaxies and the transition to low-mass star formation
Authors: Greif T. H. , Schleicher D. R. G. , Johnson J. L. , Jappsen A.-K. , Klessen R. S. , Clark P. C. , Glover S. C. O. , Stacy A. , Bromm V. 
Published: December 2008

AbstractThe formation of the first galaxies at redshifts z ~ 10−15 signaled the transition from the simple initial state of the universe to one of ever increasing complexity. We here review recent progress in understanding their assembly process with numerical simulations, starting with cosmological initial conditions and modelling the detailed physics of star formation. In this context we emphasize the importance and influence of selecting appropriate initial conditions for the star formation process. We revisit the notion of a critical metallicity resulting in the transition from primordial to present-day initial mass functions and highlight its dependence on additional cooling mechanisms and the exact initial conditions. We also review recent work on the ability of dust cooling to provide the transition to present-day low-mass star formation. In particular, we highlight the extreme conditions under which this transition mechanism occurs, with violent fragmentation in dense gas resulting in tightly packed clusters.
Dark Stars: Dark matter in the first stars leads to a new phase of stellar evolution
Authors: Freese Katherine , Spolyar Douglas , Aguirre Anthony , Bodenheimer Peter , Gondolo Paolo , Sellwood J. A. , Yoshida Naoki 
Published: December 2008

AbstractThe first phase of stellar evolution in the history of the universe may be Dark Stars, powered by dark matter heating rather than by fusion. Weakly interacting massive particles, which are their own antiparticles, can annihilate and provide an important heat source for the first stars in the the universe. This talk presents the story of these Dark Stars. We make predictions that the first stars are very massive (~800M⊙), cool (6000 K), bright (~106L⊙), long-lived (~106years), and probable precursors to (otherwise unexplained) supermassive black holes. Later, once the initial DM fuel runs out and fusion sets in, DM annihilation can predominate again if the scattering cross section is strong enough, so that a Dark Star is born again.
Searching for Pop III stars and galaxies at high redshift
Authors: Schaerer Daniel 
Published: December 2008

AbstractWe review the expected properties of Pop III and very metal-poor starbursts and the behaviour the Lyα and Heiiλ1640 emission lines, which are most likely the best/easiest signatures to single out such objects. Existing claims of Pop III signatures in distant galaxies are critically examined, and the searches for Heiiλ1640 emission at high redshift are summarised. Finally, we briefly summarise ongoing and future deep observations atz> 6 aiming in particular at detecting the sources of cosmic reionisation as well as primeval/Pop III galaxies.
Observational Search for Population III Stars in High-Redshift Galaxies
Authors: Nagao Tohru 
Published: December 2008

AbstractIn this contribution we present our new photometric search for high-z galaxies hosting Population III (PopIII) stars based on deep intermediate-band imaging observations, by using Supreme-Cam on the Subaru Telescope. By combining our new data with the existing broad-band and narrow-band data in the target field, we searched for galaxies which emit strongly both in Lyα and in Heiiλ1640 (“dual emitters”) that are promising candidates for PopIII-hosting galaxies, at 4 ≲ z ≲ 5. Although we found 10 “dual emitters”, most of them turn out to be [Oii]-[Oiii] dual emitters or Hβ-Hα dual emitters at z < 1, as inferred from their broad-band colors and from the ratio of the equivalent widths. No convincing candidate of Lyα-Heii dual emitter with SFRPopIII ≳ 2M⊙ yr−1 was found. This result disfavors low feedback models for PopIII star clusters, and implies an upper limit of the PopIII SFR density of SFRDPopIII < 5 × 10−6M⊙ yr−1 Mpc−3. This new selection method to search for PopIII-hosting galaxies should be useful in future surveys for the first observational detection of PopIII-hosting galaxies at high redshift.
Cosmic metal enrichment
Authors: Ferrara Andrea 
Published: December 2008

AbstractI review the present understanding of the process by which the universe has been enriched in the course of its history with heavy elements produced by stars and transported into the surrounding intergalactic medium. This process goes under the name of “cosmic metal enrichment” and presents some of the most challenging puzzles in present day physical cosmology. These are reviewed along with some proposed explanations that all together form a coherent working scenario.
Primordial Supernovae and the Assembly of the First Galaxies
Authors: Whalen Daniel , Van Veelen Bob , O'Shea Brian W. , Norman Michael L. 
Published: December 2008

AbstractCurrent numerical studies suggest that the first protogalaxies formed a few stars at a time and were enriched only gradually by the first heavy elements. However, these models do not resolve primordial supernova (SN) explosions or the mixing of their heavy elements with ambient gas, which could result in intervening, prompt generations of low-mass stars. We present multiscale 1D models of Population III supernovae in cosmological minihalos that evolve the blast from its earliest stages as a free expansion. We find that if the star ionizes the halo, the ejecta strongly interacts with the dense shell swept up by the H II region, potentially cooling and fragmenting it into clumps that are gravitationally unstable to collapse. If the star fails to ionize the halo, the explosion propagates metals out to 20 - 40 pc and then collapses, heavily enriching tens of thousands of solar masses of primordial gas, in contrast to previous models that suggest that such explosions ‘fizzle’. Rapid formation of low-mass stars trapped in the gravitational potential well of the halo is unavoidable in these circumstances. Consequently, it is possible that far more stars were swept up into the first galaxies, at earlier times and with distinct chemical signatures, than in present models. Upcoming measurements by the James Webb Space Telescope (JWST) and Atacama Large Millimeter Array (ALMA) may discriminate between these two paradigms.
Damped Lyα systems as probes of chemical evolution over cosmological timescales
Authors: Dessauges-Zavadsky Miroslava 
Published: December 2008

AbstractWe review the current state of knowledge of damped Lyα systems (DLAs) selected in absorption on quasar sightlines. These objects are extremely useful to study the interstellar medium of high-redshift galaxies and the nucleosynthesis in the early Universe. The characteristics of this galaxy population has been investigated for years and slowly we are getting information on their puzzling nature. Imaging atz<1 shows that DLAs are associated with a mixing bag of galaxies with no especially large contribution from dwarf galaxies. Evidence for a mild evolution of the cosmic mean metallicity with time is observed. The star formation histories of these high-redshift galaxies begin to be accessible and indicate that DLAs tend to be young, gas-dominated galaxies with low star formation rates per unit area. Finally, indirect estimation of the DLA stellar masses from the mass-metallicity relations observed for emission-selected star-forming galaxies atz= 2−3 points to intermediate-mass galaxies withM*< 109M⊙.