bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of N‐acetylcysteine on Clara cells and Clara cell 16 kDa protein in a murine model of allergen‐induced airway inflammation
Authors: NIE Xiaomeng , LI Qiang , CAI Gang , DAI Yimin , ZHANG Jun 
Published: March 2005

Objective:  The aim of this study was to investigate the number of Clara cells and the production and secretion of Clara cell 16 kDa protein (CC16) in a murine model of allergen‐induced airway inflammation, as well as the effects of N‐acetylcysteine (NAC) on CC16 and Clara cell numbers, in order to determine the mechanism of the anti‐inflammatory effect of NAC.Methodology:  BALB/c mice were divided into control, ovalbumin (OVA) and NAC groups. An allergen‐induced airway inflammation model (OVA group) was established by sensitizing and challenging mice with OVA. NAC was administered as an oral treatment. The number of Clara cells and the production of CC16 were determined by immunohistochemistry. The CC16 levels in bronchoalveolar lavage fluid (BALF) were determined by Western blotting.Results:  The proportion of Clara cells in terminal and respiratory bronchioles significantly decreased in the OVA group compared to the control group (P < 0.01). NAC treatment did not change the proportion of Clara cells in the OVA group (P > 0.05). CC16 production by Clara cells in the OVA groups was significantly lower than that of the control group (P < 0.01), but was elevated following NAC treatment (P < 0.05). The CC16 level in BALF of the OVA group was lower than that of the control group (P < 0.01), but was elevated by NAC treatment (P < 0.05). NAC reduced the total number of white cells and the percentage of eosinophils in BALF. Moreover, it inhibited airway inflammation.Conclusions:  The number of Clara cells and the production and secretion of CC16 were reduced in a murine model of allergen‐induced airway inflammation. Antioxidants can enhance the expression of CC16, which might be a mechanism by which they suppress airway inflammation.
Taxonomy and Floral Biology of Scleropogon (Eragrostideae: Gramineae)
Authors: ANTON ANA M. , CONNOR HENRY E. , ASTEGIAN MARTA E. 
Published: March 2005

Abstract
Scleropogon brevifolius is a monotypic, disjunct, New World, colony‐forming, perennial grass. Its nomenclature is relatively uncluttered. Its floral biology has always been confusing in its detail.Dioecism in S. brevifolius is expressed in sexually dimorphic inflorescences, and in adjusted floral sex ratios between male and female plants. At Uspallata in Precordilleran Argentina the primary sex ratio is met for female plants in the population (F/n=0.5), but male plants at 0.149 depart from expectation. Analysis of the remainder shows it to consist of monoecious variants among which andromonoecism (0.186) is the most significant. The contribution of ovules and pollen to the next generation by females, andromonoecids, and males is ca 80%—the balance is from very low frequency trimonoecious, monoecious, and hermaphrodite elements.The projected pathway to dioecism is via monoecism, and the numerous intermediate sex forms in the population allow the identification of many positions on that route. In the Uspallata population strict monoecism itself is <1% but premonoecism is at high frequency—ca 32%.Dioecism is still actively evolving on the male side, the early and characteristic fixation of male sterility genes having established the female element. Reasons for genetic tardiness in establishing complete control of female sterility are unknown. But the form of sexual expression displayed suggests a temporal aspect of evolution. The closest approximation in the grasses to the sex form diversity of S. brevifolius lies in New World Buchloe dactyloides which it matches in dimorphism, several sexual morphs, chamaechory, and in its colony form habit.
Molecular Systematics of the Genus Uvularia and Selected Liliales Based upon mat K and rbc L Gene Sequence Data
Authors: HAYASHI KAZUHIKO , YOSHIDA SEIJI , KATO HIDETOSHI , UTECH FREDERICK H. , WHIGHAM DENNIS F. , KAWANOI SHOICHI 
Published: March 2005

Abstract
To elucidate the affinity and phylogeny of the endemic North American genus Uvularia, two chloroplast genes, matK and rbcL, were sequenced for all five species of the genus (Uvufaria floridana, U. grandifolia, U. perfoliata, U. puberula, and U. sessilifolia) and four selected members of the Liliales (Erythronium japonicum, Disporum sessile, Medeola virginiana, and Clintonia borealis). Sequence data of both matK and rbcL genes support an Uvularia which consist of two clades, section Oakesiella and section Uvularia. Though sessile‐leaved and associated with section Oakesiella, U. puberula exhibits several intermediate characteristics between the sections. However, the overall molecular results correspond to an earlier sub‐grouping based upon gross morphology, karyology and ecological life history traits. These two cpDNA genes, notably matK tree, proved to be informative in reaffirming relationships within Uvularia. Differentiation patterns among selected morphological, karyological and life history traits were also analyzed in comparison to the resulting molecular topologies.In comparison to the selected outgroups, Disporum sessile proved to be closely related to Uvufaria in a narrowly defined Uvulariaceae ‐Uvulariea sensu Takhtajan (1997) or an expanded Colchicaceacae with a “uvularioid line”sensu Nordenstam (1998). The outgroup taxa, Erythronium, Medeola, and Clintonia, associate as a well supported lineage within a narrowly defined Liliaceae. Comment is also made on the multiple origins of berry fruits inthe Liliales.
Local adaptation in host use among marine invertebrates
Authors: Sotka Erik E. 
Published: March 2005

AbstractThe study of interactions between small invertebrates and their larger plant and animal hosts has a long tradition. One persistent theme within this literature is that spatially‐segregated populations of terrestrial and freshwater invertebrates commonly adapt to local hosts across their geographic ranges. Marine examples are rare, which leaves the impression that marine populations are less likely to adapt to locally abundant hosts and more likely to evolve generalized or phenotypically‐plastic strategies. Here, I review a short but growing list of marine invertebrates that appear to display local adaptation in host use. As expected, most of the marine examples are brooded animals with weak dispersal potential. However, some species with pelagically dispersed larvae have apparently adapted to local hosts. This surprising result is consistent with recent evidence that pelagically‐dispersed larvae are not always broadly dispersed, that strong selective pressures maintain local differences in host use, or both. The presence of host‐mediated adaptation in the sea alters predictions on how marine communities respond to disturbance, supports the notion that marine consumer‐prey interactions can coevolve, and indicates that hosts play fundamental roles in the differentiation and perhaps speciation of small marine invertebrates.
Hubbell's fundamental biodiversity parameter and the Simpson diversity index
Authors: He Fangliang , Hu Xin‐Sheng 
Published: March 2005

AbstractCentral to Hubbell's neutral theory of biodiversity is a universal, dimensionless fundamental biodiversity parameter that is the product of community size and speciation rate. One of the most important discoveries of Hubbell's theory is that the species‐abundance distribution and the species–area relationship of the neutral metacommunity is completely determined by this fundamental biodiversity parameter, although the diversity patterns of the local community are collectively determined by the biodiversity parameter and migration. Using the relative abundance of species and following the concept of heterozygosity of population genetics, here we developed an analytical relationship between this biodiversity parameter and the well‐known Simpson diversity index. This relationship helps bridge the evolutionary aspect of biodiversity to the ecological and statistical aspect of the diversity. The relationship between these two parameters suggests that diversity patterns of the metacommunity can also be equally described by the Simpson index. This relationship provides an alternative approach to interpret and estimate the fundamental biodiversity parameter for the metacommunity.
Low functional redundancy in coastal marine assemblages
Authors: Micheli Fiorenza , Halpern Benjamin S. 
Published: March 2005

AbstractThe relationship between species and functional diversity remains poorly understood for nearly all ecosystem types, yet determining this relationship is critically important for developing both a mechanistic understanding of community assembly and appropriate expectations and approaches to protecting and restoring biological communities. Here we use two distinct data sets, one from kelp forests in the Channel Islands, California, and one from a global synthesis of marine reserves, to directly test how variation in species diversity translates into changes in functional diversity. We find strong positive relationships between species and functional diversity, and increased functional diversity of fish assemblages coinciding with recovery of species diversity in marine reserves, independent of the method used for classifying species in functional groups. These results indicate that low levels of redundancy in functional species traits exist across a suite of marine systems, and that fishing tends to remove whole functional groups from coastal marine ecosystems.
Does chemical composition of individual Scots pine trees determine the biodiversity of their associated ground vegetation?
Authors: Iason Glenn R. , Lennon Jack J. , Pakeman Robin J. , Thoss Vera , Beaton Joan K. , Sim David A. , Elston David A. 
Published: March 2005

AbstractDespite plant secondary metabolites being major determinants of species interactions and ecosystem processes, their role in the maintenance of biodiversity has received little attention. In order to investigate the relationship between chemical and biological diversity in a natural ecosystem, we considered the impact of chemical diversity in individual Scots pine trees (Pinus sylvestris) on species richness of associated ground vegetation. Scots pine trees show substantial genetically determined constitutive variation between individuals in concentrations of a group of secondary metabolites, the monoterpenes. When the monoterpenes of particular trees were assessed individually, there was no relationship with species richness of associated ground flora. However, the chemical diversity of monoterpenes of individual trees was significantly positively associated with the species richness of the ground vegetation beneath each tree, mainly the result of an effect among the non‐woody vascular plants. This correlation suggests that the chemical diversity of the ecosystem dominant species has an important role in shaping the biodiversity of the associated plant community. The extent and significance of this effect, and its underlying processes require further investigation.
The functional consequences of random vs. ordered species extinctions
Authors: Gross Kevin , Cardinale Bradley J. 
Published: March 2005

AbstractRecent work suggests that the effect of extinction on ecosystem function depends on whether or not species have identical extinction risks. Here, we use a simple model of community dynamics to predict how the functional consequences of random and non‐random extinction may differ. The model suggests that when resource partitioning or facilitation structures communities, the functional consequences of non‐random extinction depend on the covariance between species traits and cumulative extinction risks, and the compensatory responses among survivors. Strong competition increases the difference between random and ordered extinctions, but mutualisms reduce the difference. When diversity affects function via a sampling effect, the difference between random and ordered extinction depends on the covariance between species traits and the change in the probability of being the competitive dominant caused by ordered extinction. These findings show how random assembly experiments can be combined with information about species traits to make qualitative predictions about the functional consequences of various extinction scenarios.
Evolution toward multi‐year periodicity in epidemics
Authors: Kamo Masashi , Sasaki Akira 
Published: March 2005

AbstractWe studied why many diseases has multi‐year period in their epidemiological dynamics, whereas a main source of the fluctuation is a seasonality with period of 1 year. Previous studies using a compartment model with seasonality in transmission rate succeed to generate a multi‐year epidemiological dynamics, when, in particular, the seasonal difference is large. However, these studies have focused on the dynamical consequence of seasonal forcing in epidemiological dynamics and an adaptation of pathogens in the seasonal environment has been neglected. In this paper, we describe our study of the evolution of pathogen's sensitivity to seasonality and show that a larger fluctuation in the transmission rate can be favored in the life history evolution of pathogens, suggesting that multi‐year periodicity may evolve by natural selection. Our result proposes a new aspect of the evolution of multi‐year epidemics.
Susceptibility of Italian agile frog populations to an emerging strain ofRanavirusparallels population genetic diversity
Authors: Pearman Peter B. , Garner Trenton W. J. 
Published: March 2005

AbstractWestern populations of the Italian agile frog (Rana latastei) experience widespread genetic depletion. Based on population genetic theory, molecular models of immunity and previous empirical studies, population genetic depletion predicts increased susceptibility of populations to emergent pathogens. We experimentally compared susceptibility ofR. latasteipopulations upon exposure to an emerging strain ofRanavirus, frog virus 3 (FV3), using six populations spanning the geographical range and range of population genetic diversity found in nature. Our findings confirm this prediction, suggesting that the loss of genetic diversity accompanying range expansion and population isolation is coincident with increased mortality risk from an emergent pathogen. Loss of heterozygosity and escape from selection imposed by immunologically cross‐reactive pathogens may potentially generate range‐wide variation in disease resistance.
Allometric growth, life‐history invariants and population energetics
Authors: Economo Evan P. , Kerkhoff Andrew J. , Enquist Brian J. 
Published: March 2005

AbstractPopulation and community level processes must be at least partially determined by variation in the body sizes of constituent individuals, implying quantitative scaling relations can be extended to account for variation in those processes. Here we integrate allometric growth and life‐history invariant theories, and use this approach to develop theory describing the energetics of stationary populations. Our predictions approximate, with no free parameters, the scaling of production/biomass and assimilation/biomass ratios in mammalian populations and work partially for fish populations. This approach appears to be a promising direction and suggests the need for further development of the growth and life‐history models, and extensions of those theories.
Power laws without complexity
Authors: Solow Andrew R. 
Published: March 2005

AbstractPower laws have been invoked in describing the sizes of a wide variety of objects in evolution and ecology. The apparent ubiquity of power laws is commonly attributed to a form of complex behaviour called self‐organizing criticality. It is shown that power law behaviour inevitably arises from the statistics of large values from heavy‐tailed distributions and that such distributions can be generated by processes that do not involve self‐organized criticality. It follows that power law behaviour cannot be taken as prima facie evidence of self‐organizing criticality.
Big mothers invest more in daughters – reversed sex allocation in a weakly polygynous mammal
Authors: Hewison A. J. Mark , Gaillard Jean‐Michel , Kjellander Petter , Toïgo Carole , Liberg Olof , Delorme Daniel 
Published: March 2005

AbstractHow mothers allocate resources to offspring is central to understanding life history strategies. High quality mothers are predicted to favour investment in sons over daughters when to do so increases inclusive fitness. This is the case in ungulates with polygynous mating systems, where reproductive success is more variable among males than females, but information is scarce on sex allocation in less polygynous species. Here, for the weakly dimorphic roe deer, we show that as maternal capacity to invest increases, mothers increase allocation to daughters more than to sons, so that relative allocation to daughters increases markedly with increasing maternal quality. This cannot be explained by a between sex difference in growth priority, hence we conclude that this is evidence for active maternal discrimination. Further, we demonstrate that condition differences between offspring persist to adulthood. For high quality mothers of weakly polygynous species, daughters may be more valuable than sons.
Retinal vascular image analysis as a potential screening tool for cerebrovascular disease: a rationale based on homology between cerebral and retinal microvasculatures
Authors: Patton Niall , Aslam Tariq , MacGillivray Thomas , Pattie Alison , Deary Ian J. , Dhillon Baljean 
Published: March 2005

AbstractThe retinal and cerebral microvasculatures share many morphological and physiological properties. Assessment of the cerebral microvasculature requires highly specialized and expensive techniques. The potential for using non‐invasive clinical assessment of the retinal microvasculature as a marker of the state of the cerebrovasculature offers clear advantages, owing to the ease with which the retinal vasculature can be directly visualizedin vivoand photographed due to its essential two‐dimensional nature. The use of retinal digital image analysis is becoming increasingly common, and offers new techniques to analyse different aspects of retinal vascular topography, including retinal vascular widths, geometrical attributes at vessel bifurcations and vessel tracking. Being predominantly automated and objective, these techniques offer an exciting opportunity to study the potential to identify retinal microvascular abnormalities as markers of cerebrovascular pathology. In this review, we describe the anatomical and physiological homology between the retinal and cerebral microvasculatures. We review the evidence that retinal microvascular changes occur in cerebrovascular disease and review current retinal image analysis tools that may allow us to use different aspects of the retinal microvasculature as potential markers for the state of the cerebral microvasculature.
Relationship of brain and skull in pre‐ and postoperative sagittal synostosis
Authors: Aldridge Kristina , Kane Alex A. , Marsh Jeffrey L. , Yan Peng , Govier Daniel , Richtsmeier Joan T. 
Published: March 2005

AbstractModels of vertebrate skull evolution stress the coordinated developmental relationship between the skull and the brain that it houses. This study investigates the relationship between altered skull morphology and brain morphology in premature fusion of the cranial sagittal suture (isolated sagittal synostosis; ISS), a condition associated with dysmorphology of both neurocranium and brain. Although the skull displays a more normal shape following reconstructive cranial vault surgery, effects of this surgery on the brain have not been investigated. Landmark coordinate data were collected from three‐dimensional magnetic resonance imaging reconstructions of the brain in a sample of ISS patients and an age‐matched unaffected cohort. These data were analysed using Euclidean distance matrix analysis (EDMA). Results show that the brain in ISS is dysmorphic preoperatively, displaying a posteriorly directed neural expansion that does not ‘worsen’ with growth. Postoperatively, the brain in ISS displays a more globular shape overall as compared with the preoperative morphology, but differs from normal in its subcortical morphology. These results show that the ISS brain is altered following neurocranial surgery, but does not more closely approximate that of unaffected individuals. This suggests that although the brain is affected by manipulation of the skull, it retains a growth pattern that is, at least in part, independent of the skull.
Microvascular patterns in human medullary tegmentum at the level of the area postrema
Authors: Porzionato Andrea , Macchi Veronica , Morsut Leonardo , Parenti Anna , De Caro Raffaele 
Published: March 2005

AbstractThe aim of the present study was to evaluate the regional differences in microvessel density (MVD) of the human medullary tegmentum in adults and newborns/infants. Transverse serial sections of formalin‐fixed, paraffin‐embedded brainstems, taken from 16 adult and eight newborn/infant subjects, were stained with anti‐von Willebrand factor (vWF) polyclonal antibodies. The boundaries of the area postrema (AP), dorsal motor vagal nucleus (DMVN), solitary tract nucleus (STN), solitary tract (ST) and hypoglossal nucleus (XII) were defined, all vessels were counted and the values were divided by the areas. In adult cases, statistically significant heterogeneity in MVD was found among the nuclei studied (P < 0.001). DMVN and AP showed higher MVD with respect to XII and ST (P < 0.001). The MVD of STN was lower with respect to DMVN (P < 0.001) and higher with respect to XII and ST (P < 0.05). The MVD and capillary density of the AP of newborns/infants were not significantly different with respect to adults. In sections of the medulla of adult subjects stained with anti‐vWF, all vessels showed an intense reaction of endothelial cells whereas in the DMVN, XII, STN and ST of newborns/infants, only rare, isolated vessels showed anti‐vWF reactivity and in the AP, 41 ± 21% of vessels expressed vWF. Differences in MVD among the nuclei may be related to their different functions and metabolic demands. Light and heterogeneous expression of vWF in endothelial cells of newborns/infants indicates that differentiation of microvasculature in the human medullary tegmentum extends beyond fetal stages.
Structure and innervation of the tusk pulp in the African elephant (Loxodonta africana)
Authors: Weissengruber G. E. , Egerbacher M. , Forstenpointner G. 
Published: March 2005

AbstractAfrican elephants (Loxodonta africana) use their tusks for digging, carrying and behavioural display. Their healing ability following traumatic injury is enormous. Pain experience caused by dentin or pulp damage of tusks seems to be negligible in elephants. In this study we examined the pulp tissue and the nerve distribution using histology, electron microscopy and immunhistochemistry. The results demonstrate that the pulp comprises two differently structured regions. Randomly orientated collagen fibres characterize a cone‐like part lying rostral to the foramen apicis dentis. Numerous nerve fibres and Ruffini endings are found within this cone. Rostral to the cone, delicate collagen fibres and large vessels are orientated longitudinally. The rostral two‐thirds of the pulp are highly vascularized, whereas nerve fibres are sparse. Vessel and nerve fibre distribution and the structure of connective tissue possibly play important roles in healing and in the obviously limited pain experience after tusk injuries and pulp alteration. The presence of Ruffini endings is most likely related to the use of tusks as tools.