bluuebunny/crossref_metadata_2025 huggingface dataset:
Historical biogeography of olive domestication (Olea europaeaL.) as revealed by geometrical morphometry applied to biological and archaeological material
Authors: Terral Jean‐Frédéric , Alonso Natalia , Capdevila Ramon Buxó i , Chatti Noureddine , Fabre Laurent , Fiorentino Girolamo , Marinval Philippe , Jordá Guillem Pérez , Pradat Bénédicte , Rovira Núria , Alibert Paul
Published: October 2010

Aim This study intends to improve our understanding of historical biogeography of olive domestication in the Mediterranean Basin, particularly in the north‐western area.

Location Investigations were performed simultaneously on olive stones from extant wild populations, extant cultivated varieties from various Mediterranean countries, and archaeological assemblages of Spanish, French and Italian settlements.

Methods A combination of morphometrics (traditional and geometrical) allowed us to study both the size and shape of endocarp structure. Concerning shape, a size‐standardized method coupled with fitted polynomial regression analysis was performed.

Results We found morphological criteria for discriminating between wild and cultivated olive cultivars, and established patterns of morphological variation of olive material according to the geographical origin (for extant material) and to the age of the olive forms (for archaeological material). Levels of morphological convergences and divergences between wild olive populations and cultivated varieties are presented as evidence.

Main conclusions Morphological changes of endocarps of olive under domestication at both geographical and chronological scales provide new criteria for the identification of olive cultivars. They allow to determine the origins of cultivated forms created and/or introduced in the north‐western Mediterranean regions and to understand how human migrations affected the rest of the Western Mediterranean regions. A model of diffusion of olive cultivation is proposed. It shows evidence of an indigenous origin of the domestication process, which is currently recognized in the north‐western area since the Bronze Age.
The biogeography of aquatic macrophytes in North America since the Last Glacial Maximum
Authors: Sawada M. , Viau A. E. , Gajewski K.
Published: October 2010

AimTo document the post‐glacial migration of the major aquatic macrophytes of North America.

LocationNorth America north of Mexico.

MethodsAquatic macrophyte pollen were extracted from the North American Pollen Database. The modern pollen distribution was mapped and related to the climate to document the geographical and climatic constraints on these taxa. The fossil pollen were mapped at 2‐ka intervals for the past 21 ka.

ResultsNumerous genera were present in ice‐free Alaska during the Last Glacial Maximum, and south of the Laurentide Ice Sheet in the southeast. Those taxa with the widest modern climatic ranges migrated rapidly into ice‐marginal areas, first in the west and then in the east of North America. Subsequent changes in the range and abundance were smaller.

Main conclusionsThere were four migration routes of aquatic macrophytes during the late‐glacial and post‐glacial periods: a southward migration from Alaska between 14–13 and ka, a northern migration in the west at the same time into the ice‐free Cordilleran region, and movements east and west of Appalachia as early as 19 ka for some taxa into the lower Mississippi and into the upper Mississippi and Great Lakes by 11 ka. As the Laurentide ice sheet wasted, aquatic taxa with the broadest contemporary temperature tolerances rapidly occupied ice‐marginal environments.
Australian biogeographical connections and the phylogeny of large genera in the plant family Myrtaceae
Authors: Ladiges Pauline Y. , Udovicic Frank , Nelson Gareth
Published: October 2010

AimTo compare the phylogeny of the eucalypt and melaleuca groups with geological events and ages of fossils to discover the time frame of clade divergences.

LocationAustralia, New Caledonia, New Guinea, Indonesian Archipelago.

MethodsWe compare published molecular phylogenies of the eucalypt and melaleuca groups of the plant family Myrtaceae with geological history and known fossil records from the Cretaceous and Cenozoic.

ResultsThe Australasian eucalypt group includes seven genera, of which some are relictual rain forest taxa of restricted distribution and others are species‐rich and widespread in drier environments. Based on molecular and morphological data, phylogenetic analyses of the eucalypt group have identified two major clades. The monotypicArillastrumendemic to New Caledonia is related in one clade to the more species‐richAngophora,CorymbiaandEucalyptusthat dominate the sclerophyll vegetation of Australia. Based on the time of rifting of New Caledonia from eastern Gondwana and the age of fossil eucalypt pollen, we argue that this clade extends back to the Late Cretaceous. The second clade includes three relictual rain forest taxa, withAllosyncarpiafrom Arnhem Land the sister taxon toEucalyptopsisof New Guinea and the eastern Indonesian archipelago, andStockwelliafrom the Atherton Tableland in north‐east Queensland. As monsoonal, drier conditions evolved in northern Australia, Arnhem Land was isolated from the wet tropics to the east and north during the Oligocene, segregating ancestral rain forest biota. It is argued also that the distribution of species inEucalyptopsisandEucalyptussubgenusSymphyomyrtusendemic in areas north of the stable edge of the Australian continent, as far as Sulawesi and the southern Philippines, is related to the geological history of south‐east Asia‐Australasia. Colonization (dispersal) may have been aided by rafting on micro‐continental fragments, by accretion of arc terranes onto New Guinea and by land brought into closer proximity during periods of low sea‐level, from the Late Miocene and Pliocene. The phylogenetic position of the few northern, non‐Australian species ofEucalyptussubgenusSymphyomyrtussuggests rapid radiation in the large Australian sister group(s) during this time frame. A similar pattern, connecting Australia and New Caledonia, is emerging from phylogenetic analysis of theMelaleucagroup (Beaufortiasuballiance) within Myrtaceae, withMelaleucabeing polyphyletic.

Main conclusionThe eucalypt group is an old lineage extending back to the Late Cretaceous. Differentiation of clades is related to major geological and climatic events, including rifting of New Caledonia from eastern Gondwana, development of monsoonal and drier climates, collision of the northern edge of the Australian craton with island arcs and periods of low sea level. Vicariance events involve dispersal of biota.
A mesoscale analysis of floristic patterns in the south‐west Finnish Archipelago
Authors: Korvenpää Turkka , Von Numers Mikael , Hinneri Sakari
Published: October 2010

AimTo identify the ecological gradients based on the flora on a mesoscale in an archipelago. To interpret the results of the ordination and the classification of a grid cell‐based botanical data set, with several environmental and geographical attributes. To compare the mesoscale distribution patterns of vascular plants with patterns previously observed on an island scale, and to develop a floristic zonation of the study area.

LocationThe south‐west Finnish Archipelago.

MethodsVascular plant species‐lists from over 1500 localities were assigned to 5 × 5 km grid cells. The grid cell‐based floristic data were subjected to both unconstrained [detrended correspondence analysis (DCA)] and constrained [detrended canonical correspondence analysis (DCCA)] gradient analyses. The results of DCA were interpreted with calculated weighted averages of Ellenberg's indicator values for vascular plants, the number of occurring taxa and indices for the strength of human influence and the occurrence of limestone. The results of DCCA were interpreted with geographical attributes of the grid cells and the occurrence of limestone. The grid cells were clustered using two‐way indicator species analysis (twinspan).

ResultsBoth the unconstrained and the constrained ordinations gave consistent and interpretable results. The main ecological gradient runs from the grid cells containing species‐rich islands with high human impact to grid cells containing species‐poor islands with low human impact. This gradient also represents the continuum from areas with large islands near the mainland, to the outermost areas at the edge of the open sea. The secondary gradient was shown to be a gradient of soil reaction.twinspangave a clustering primarily based on the location of the grid cells on an inner–outer archipelago gradient, but the occurrence of limestone also influenced the classification. The archipelago was divided into five non‐homogeneous areas based on thetwinspanclusters. The detected gradients correspond well with the gradients detected in a similar island‐level analysis.

Main conclusionsThe two major ecological gradients in the study area seem to be robust, which is indicated by the similar results obtained both on an island and on a mesoscale. A shift from local and regional processes to broader geographical gradients probably starts to occur at the applied scale. The distribution patterns are strongly affected by the inner–outer archipelago gradient and the occurrence of limestone.
A comparison of taiga flora in north‐eastern Russia and Alaska/Yukon
Authors: Swanson David K.
Published: October 2010

Aim  To understand the similarities and differences between the taiga floras of far north‐eastern Asia and north‐western North America in the light of their Tertiary and Quaternary histories. Does the taiga flora follow the tundra pattern (Asian–American commonality of species as a result of continuity through the Quaternary), the temperate forest pattern (distinct species because of late Tertiary disjunction), a combination of these two patterns, or some pattern unique to the taiga?

Location  The taiga regions of interior Alaska and the Yukon in North America (the ‘Alaskan taiga’), and the Kolyma and eastern Indigirka River basins in Russia (the ‘Kolyma taiga’). The study areas include both forested and unforested habitats below elevational treeline. The two regions have similar climate and topography and were linked via the Bering Land Bridge in the Tertiary and for several extended periods during Quaternary cold periods.

Methods  Systematic comparison of the vascular floras of the two regions from published sources; and review of palaeoecological literature for the region.

Results  Of the 796 species found in the study areas, 27% occur only in the Alaskan taiga, 35% occur only in the Kolyma taiga, and 38% occur in both the regions. The following subsets of species show a high proportion of species in common between the study areas (subsets are not mutually exclusive): plants that occur on the tundra and the taiga, non‐flowering plants, abundant taiga understory plants, and wetland and aquatic plants. A lower proportion of shared plants was noted for warm, south‐facing steppe communities. No tree species are common to both areas.

Main conclusions  The Bering Strait region in the Quaternary has acted as a biogeographical filter for taiga plants. Significant divergence between northeast Asia and northwest North America has developed among the more southerly ranging fraction of the flora (e.g. trees), while the more cosmopolitan and the most cold‐adapted elements of the taiga flora are common to both areas. Many plants in the former group have been disjunct between Asia and North America for millions of years, while many plants in the latter group have probably maintained continuity between the study areas via the Bering Land Bridge through much of the late Tertiary and Quaternary periods. Repeated extirpation of the less cold‐adapted species from both study areas during Pleistocene cold periods has probably enhanced floristic differences between the two regions.
Exotic plant invasions of vernal pools in the Central Valley of California, USA
Authors: Gerhardt Fritz , Collinge Sharon K.
Published: October 2010

Aim To better understand patterns of community invasibility, we examined exotic plant invasions along an environmental gradient found in vernal pools in the Central Valley of California. Specifically, we analysed the distribution and abundance of exotic plants in relation to pool size, seasonal inundation, soil and nutrient properties, the native plant community, and disturbance history.

Location We studied patterns of exotic plant invasions in a complex of natural and restored vernal pools at Travis Air Force Base near Fairfield, California.

Methods In thirty natural and thirty restored pools, we conducted field surveys to measure the distribution and abundance of exotic and native plants and several descriptors of the abiotic environment. We used multiple linear regressions to analyse exotic species richness and cover and the abundances of individual exotic species in relation to pool type, fire history, pool size, water depth, native plant cover, and six soil and nutrient properties.

Results Exotic species richness was greater in burned than unburned pools, and exotic plant cover was greater in natural than restored pools. Both exotic species richness and cover decreased with increasing water depth. Exotic species richness was not related to native plant cover, but exotic plant cover decreased with increasing native plant cover. Eighteen of the nineteen most common exotic species showed significant relationships with pool type (twelve species), water depth (eleven species), fire history (nine species), native plant cover (six species), and pool size (five species). Most species increased in abundance with decreasing water depth (nine species) or were more abundant in natural (eight species) or burned pools (six species).

Main conclusions These results suggest that both abiotic factors, especially those associated with seasonal inundation, and interactions with the native plant community play important roles in determining the invasibility of vernal pool plant communities. In particular, abiotic constraints may limit exotic plant invasions in more stressful environments, and interactions with the native plant community may limit invasions in more benign environments.
Biogeography ofPlagiochila(Hepaticae): natural species groups span several floristic kingdoms
Authors: Groth Henk , Lindner Melanie , Wilson Rosemary , Hartmann Florian A. , Schmull Michaela , Rob Gradstein S. , Heinrichs Jochen
Published: October 2010

AimThis paper presents a synthesis of our recent results regarding the biogeography ofPlagiochilausing a molecular approach, and documents intercontinental ranges within this largest genus of the hepatics.

MethodsA maximum likelihood analysis of sixty‐one nrITS sequences ofPlagiochilawas performed and the molecular topology obtained was compared with morphological, phytochemical and geographical data.

ResultsOur molecular data set allowed the identification of elevenPlagiochilasections, the majority of which cover at least two floristic kingdoms. Seven sections have species in Europe (sect.Arrectae,Carringtoniae,Fuscoluteae,Glaucescentes,Plagiochila,Rutilantes,Vagae).Plagiochilaspecies from Atlantic Europe are usually close to or conspecific with neotropical taxa, whereas species widespread in Europe are closely related to Asian ones and not to those in the Neotropics.

Plagiochilasect.Arrectaerepresents a neotropical – Atlantic European clade. The section is not closely related – as has often been suggested – to the morphologically similar sect.Zonataefrom Asia and western North America. Sequence data show that the AfricanP. integerrimaand the neotropicalP. subplanaare members of the Asian sect.Cucullatae(sect.Ciliatae, syn. nov.), which becomes pantropical in distribution. An ITS sequence ofP. boryanafrom Uganda confirms the Afro‐American range of the primarily neotropical sect.Hylacoetes. Similarities in sporophyte morphology between the sect.Cucullataeand sect.Hylacoetesare the result of parallel evolution.

Main conclusionsOur results indicate that intercontinental ranges at section and species level are common inPlagiochila.Carl's (1931)subdivision ofPlagiochilainto sections restricted to one floristic kingdom is outdated. Biogeographical patterns inPlagiochilaare not dissimilar to those of other groups of bryophytes but elucidation of the geographical ranges of the taxa requires a molecular approach.

Contrary to earlier belief, mostPlagiochilaspecies from Atlantic Europe do not have close relatives in Asia but are conspecific with or closely related to species from tropical America.
Climatic and biophysical controls on conifer species distributions in mountain forests of Washington State, USA
Authors: McKenzie Donald , Peterson David W. , Peterson David L. , Thornton Peter E.
Published: October 2010

AbstractAimThe purpose of this study was to quantify relationships between conifer species distributions and climatic and biophysical variables, in order to provide better insight into the potential for redistribution of species on the landscape in response to climatic change.

LocationData are from 10,653 georeferenced sites in Washington State, USA, along a longitudinal gradient from west of the crest of the Cascade Range to the beginnings of the western slope of the Rocky Mountains, and across two physiographic provinces, the Northern Cascades, characterized by steep, rugged topography, and the Okanogan Highlands, presenting moderate slopes and broad rounded summits.

MethodsTree data were drawn from the USDA Forest Service Area Ecology Program database, collected in mature, undisturbed stands. We compared simple climatic variables (annual temperature, growing‐degree days, annual and seasonal precipitation) to biophysical variables (soil, hydrologic, and solar radiation) derived from climatic variables. Climatic and biophysical variables were taken from the output of climatological and hydrological simulation models and estimated for each plot in the tree database. Generalized linear models were used, for each of fourteen tree species, at multiple spatial extents, to estimate the probability of occurrence of that species as a function of climatic and biophysical predictors. Models were validated by a combination of bootstrapping and estimating receiver operating characteristic (ROC) curves.

ResultsFor the majority of species, we were able to fit variables representing both moisture and temperature gradients, and in all but a few cases these models identified a unimodal response of species occurrence to these gradients. In some cases the ecological/environmental niche of a species had been clearly captured by the model, whereas in others a longer gradient in the predictor variable(s) would be needed. Responses of most species were consistent across three spatial scales.

Main conclusionsBy identifying the ecological niches of multiple species, we can forecast their redistribution on the landscape in response to climatic change, evaluate the predictions of simulation models, and alert managers to particularly sensitive or vulnerable ecosystems and landscapes.
Biogeography and phylogeny of the New Zealand cicada genera (Hemiptera: Cicadidae) based on nuclear and mitochondrial DNA data
Authors: Arensburger Peter , Buckley Thomas R. , Simon Chris , Moulds Max , Holsinger Kent E.
Published: October 2010

Aim Determine the geographical and temporal origins of New Zealand cicadas.

Location New Zealand, eastern Australia and New Caledonia.

Methods DNA sequences from 14 species of cicadas from New Zealand, Australia, and New Caledonia were examined. A total of 4628 bp were analysed from whole genome extraction of four mitochondrial genes (cytochrome oxidase subunits I and II, and ribosomal 12S and 16S subunits) and one nuclear gene (elongation factor‐1 alpha). These DNA sequences were aligned and analysed using standard phylogenetic methods based primarily on the maximum likelihood optimality criterion. Dates of divergences between clades were determined using several molecular clock methods.

Results New Zealand cicadas form two well‐defined clades. One clade groups with Australian taxa, the other with New Caledonian taxa. The molecular clock analyses indicate that New Zealand genera diverged from the Australian and New Caledonian genera within the last 11.6 Myr.

Main conclusions New Zealand was likely colonized by two or more invasions. One NZ lineage has its closest relatives in Australia and the other in New Caledonia. These invasions occurred well after New Zealand became isolated from other land masses, therefore cicadas must have crossed large bodies of water to reach New Zealand.
Phylogeography ofPtychadena mascareniensissuggests transoceanic dispersal in a widespread African‐Malagasy frog lineage
Authors: Vences Miguel , Kosuch Joachim , Rödel Mark‐Oliver , Lötters Stefan , Channing Alan , Glaw Frank , Böhme Wolfgang
Published: October 2010

Aim The Mascarene ridged frog,Ptychadena mascareniensis, is the only African amphibian species thought to occur on Madagascar and on the Seychelles and also Mascarene islands. We explored its phylogenetic relationships and intraspecific genetic differentiation to contribute to the understanding of transoceanic dispersal in amphibians.

Methods Fragments of the mitochondrial 16S rRNA gene were sequenced from specimens collected over most of the distribution area ofP. mascareniensis, including populations from Madagascar, Mascarenes and Seychelles.

Results We identified five deeply divergent clades having pairwise divergences >5%, which probably all represent cryptic species in aP. mascareniensiscomplex. One of these seems to be restricted to Madagascar, the Mascarenes and the Seychelles. Sequences obtained from topotypic material (Réunion) were identical to the most widespread haplotype from Madagascar. The single Mauritian/Seychellean haplotype differed by only one mutation from a Malagasy haplotype.

Main conclusions It is likely that the Mascarene and Seychellean populations were introduced from Madagascar by humans. In contrast, the absence of the Malagasy haplotypes from Africa and the distinct divergences among Malagasy populations (16 mutations in one divergent hapolotype from northern Madagascar) suggest that Madagascar was populated byPtychadenabefore the arrival of humansc.2000 years ago. Because Madagascar has been separated from Africa since the Jurassic, this colonization must have taken place by overseas rafting, which may be a more widespread dispersal mode in amphibians than commonly thought.
Phylogenetic relationships and biogeography of midwife toads (Discoglossidae: Alytes)
Authors: Martínez‐Solano I. , Gonçalves H. A. , Arntzen J. W. , García‐París M.
Published: October 2010

Aim  To devise a robust phylogenetic hypothesis for midwife toads (Alytes: Anura: Discoglossidae) and to discuss its implications for the reconstruction of the biogeographical history of the group.

Location  Western Palearctic.

Methods  Analysis of sequences of mitochondrial DNA (cytochrome b and 16S RNA, 861 bp) and 29 characters of cranial osteology of all species and subspecies within Alytes.

Results  Phylogenetic analyses support a sister group relationship between Alytes dickhilleni and A. muletensis, and of this clade with A. maurus. The monophyly of A. obstetricans is controversial; in particular, the phylogenetic position of A. obstetricans almogavarii is uncertain. The estimated dates for the cladogenetic events within Alytes are congruent with those derived from independent analyses (allozymes), except for the differentiation of A. o. almogavarii and the split between A. dickhilleni and A. muletensis.

Main conclusions  The phylogeny based on the analysis of morphological and mtDNA data differs from previous hypotheses in the positions of A. o. almogavarii and A. maurus. Events associated with the radiation of Alytes are the formation of large inland saline lakes in Iberia c. 16 Ma and the 11 ° C dramatic decrease in average annual temperature during the Middle–Late Badenian transition c. 14–13.5 Ma (A.cisternasii vs. the ancestor of the remaining clades), the structuring of the Neo‐Pyrenees and the reopening of the Betic Strait c. 10–8 Ma(A. o. almogavarii vs. A. obstetricans and vs. the subgenus Baleaphryne), the opening of the Gibraltar Strait at the end of the Messinian Salinity Crisis at c. 5.3 Ma (A. maurus vs. the ancestor of the A. dickhilleni A. muletensis clade) and a transmarine colonization event at c. 3 Ma (the ancestor of A. muletensis vs. A. dickhilleni). Following the new hypothesis, A. maurus, previously considered a subspecies of A. obstetricans, deserves species status. Second, A. o. almogavarii is a well‐differentiated lineage that was isolated from other A. obstetricans more than c. 5 Ma, but later lost its genetic and specific identity following secondary contact, hybridization and introgression with the main stock. The presence of a marked morphological and genetic diversity within A. obstetricans renders reconstruction of the evolutionary history of the genus more complicated than previously appreciated.
Island biogeography and the species richness of introduced mammals on New Zealand offshore islands
Authors: Russell J. C. , Clout M. N. , McArdle B. H.
Published: October 2010

Aim  To investigate and establish the significance of various island biogeographic relationships (geographical, ecological and anthropological) with the species richness of introduced mammals on offshore islands.

Location  The 297 offshore islands of the New Zealand archipelago (latitude: 34–47°S; longitude: 166–179°E).

Methods  Data on New Zealand offshore islands and the introduced mammals on them were collated from published surveys and maps. The species richness of small and large introduced mammals were calculated for islands with complete censuses and regressed on island characteristics using a Poisson distributed error generalized linear model. To estimate the ‘z‐value’ for introduced mammals on New Zealand islands, least‐squares regression was used [log10 S vs. log10 A].

Results  High collinearity was found between the area, habitat diversity and elevation of islands. The island characteristics related to the species richness of introduced mammals differed predictably between large and small mammals. The species richness of introduced large mammals was mostly related to human activities on islands, whereas species richness of introduced small mammals was mostly related to island biogeographical parameters. The ‘z‐value’ for total species richness is found to be expectedly low for introduced mammals.

Main conclusions  Distance appears to have become ecologically trivial as a filter for introduced mammal presence on New Zealand offshore islands. There is strong evidence of a ‘small island’ effect on New Zealand offshore islands. The species richness of both small and large introduced mammals on these islands appears to be most predominantly related to human use, although there is some evidence of natural dispersal for smaller species. The ecological complexity of some islands appears to make them less invasible to introduced mammals. Some human activities have an interactive effect on species richness. A small number of islands have outlying species richness values above what the models predict, suggesting that the presence of some species may be related to events not accounted for in the models.
Factors controlling the spatial species richness pattern of four groups of terrestrial vertebrates in an area between two different biogeographic regions in northern Spain
Authors: Nogués‐Bravo David , Martínez‐Rica Juan Pablo
Published: October 2010

Aim  To examine the influence of environmental variables on species richness patterns of amphibians, reptiles, mammals and birds and to assess the general usefulness of regional atlases of fauna.

Location  Navarra (10,421 km2) is located in the north of the Iberian Peninsula, in a territory shared by Mediterranean and Eurosiberian biogeographic regions. Important ecological patterns, climate, topography and land‐cover vary significantly from north to south.

Methods  Maps of vertebrate distribution and climatological and environmental data bases were used in a geographic information systems framework. Generalized additive models and partial regression analysis were used as statistical tools to differentiate (A) the purely spatial fraction, (B) the spatially structured environmental fraction and (C) the purely environmental fraction. In this way, we can evaluate the explanatory capacity of each variable, avoiding false correlations and assessing true causality. Final models were obtained through a stepwise procedure.

Results  Energy‐related features of climate, aridity and land‐cover variables show significant correlation with the species richness of reptiles, mammals and birds. Mammals and birds exhibit a spatial pattern correlated with variables such as aridity index and vegetation land‐cover. However, the high values of the spatially structured environmental fraction B and the low values of the purely environmental fraction A suggest that these predictor variables have a limited causal relationship with species richness for these vertebrate groups. An increment in land‐cover diversity is correlated with an increment of specific richness in reptiles, mammals and birds. No variables were found to be statistically correlated with amphibian species richness.

Main conclusions  Although aridity and land‐cover are the best predictor variables, their causal relationship with species richness must be considered with caution. Historical factors exhibiting a similar spatial pattern may be considered equally important in explaining the patterns of species richness. Also, land‐cover diversity appears as an important factor for maintaining biological diversity. Partial regression analysis has proved a useful technique in dealing with spatial autocorrelation. These results highlight the usefulness of coarsely sampled data and cartography at regional scales to predict and explain species richness patterns for mammals and birds. The accuracy of models appears to be related to the range perception of each group and the scale of the information.
Expression of bone morphogenetic proteins and cartilage‐derived morphogenetic proteins during osteophyte formation in humans
Authors: Zoricic Sanja , Maric Ivana , Bobinac Dragica , Vukicevic Slobodan
Published: October 2010

Bone‐ and cartilage‐derived morphogenetic proteins (BMPs and CDMPs), which are TGFβ superfamily members, are growth and differentiation factors that have been recently isolated, cloned and biologically characterized. They are important regulators of key events in the processes of bone formation during embryogenesis, postnatal growth, remodelling and regeneration of the skeleton. In the present study, we used immunohistochemical methods to investigate the distribution of BMP‐2, ‐3, ‐5, ‐6, ‐7 and CDMP‐1, ‐2, ‐3 in human osteophytes (abnormal bony outgrowths) isolated from osteoarthritic hip and knee joints from patients undergoing total joint replacement surgery. All osteophytes consisted of three different areas of active bone formation: (1) endochondral bone formation within cartilage residues; (2) intramembranous bone formation within the fibrous tissue cover and (3) bone formation within bone marrow spaces. The immunohistochemistry of certain BMPs and CDMPs in each of these three different bone formation sites was determined. The results indicate that each BMP has a distinct pattern of distribution. Immunoreactivity for BMP‐2 was observed in fibrous tissue matrix as well as in osteoblasts; BMP‐3 was mainly present in osteoblasts; BMP‐6 was restricted to young osteocytes and bone matrix; BMP‐7 was observed in hypertrophic chondrocytes, osteoblasts and young osteocytes of both endochondral and intramembranous bone formation sites. CDMP‐1, ‐2 and ‐3 were strongly expressed in all cartilage cells. Surprisingly, BMP‐3 and ‐6 were found in osteoclasts at the sites of bone resorption. Since a similar distribution pattern of bone morphogenetic proteins was observed during embryonal bone development, it is suggested that osteophyte formation is regulated by the same molecular mechanism as normal bone during embryogenesis.
Concordia discors: duality in the origin of the vertebrate tail
Authors: Handrigan Gregory R.
Published: October 2010

The vertebrate tail is an extension of the main body axis caudal to the anus. The developmental origin of this structure has been a source of debate amongst embryologists for the past century. Some view tail development as a continuation of the morphogenetic processes that shape the head and trunk (i.e. gastrulation). The alternative view, secondary development, holds that the tail forms in a manner similar to limb development, i.e. by secondary induction. Previous developmental studies have provided support for both views. Here I revisit these studies, describing caudal morphogenesis in select vertebrates, the associated genes and developmental defects, and, as a relevant aside, consider the developmental and evolutionary relationships of primary and secondary neurulation. I conclude that caudal development enlists both gastrulation and secondary induction, and that the application of recent high‐resolution cell labelling technology may clarify how these discordant programmes interact in building the vertebrate tail.
Histological and immunohistological investigation of the lymphoid tissue in normal and mycobacteria‐affected specimens of the Rufous Hare‐wallaby (Lagorchestes hirsutus)
Authors: Young L. J. , McFarlane R. , Slender A. L. , Deane E. M.
Published: October 2010

The histology of the spleen, lymph nodes, Gut‐associated lymphoid tissue (GALT) and Bronchus‐associated lymphoid tissue (BALT) are described for samples collected opportunistically from healthy and mycobacteria‐affected specimens of the endangered marsupialLagorchestes hirsutus, the Rufous Hare‐wallaby. The structural elements, organization and distribution of T and B lymphocytes determined by immunohistological techniques using species cross‐reactive antibodies in the lymph nodes, spleen and GALT of this species demonstrated lymphoid cell distributions that were consistent with other marsupial and eutherian mammals. The tissues of animals identified as acid‐fast positive displayed immunopathology consistent with the responses to intracellular bacteria displayed in some eutherian mammals and included the presence of focal lesions, giant cells in the lung and lymphoid aggregations situated adjacent to blood and airway vessels. This is the first study to describe the lymphoid tissue of this rare macropod species and the first to document the tissue bed response to mycobacteria.
The equine hind limb is actively stabilized during standing
Authors: Schuurman Simon O. , Kersten Wim , Weijs Wim A.
Published: October 2010

Horses spend much of their life standing, and they are believed to be able to keep their limbs straight without muscular effort. We tested the hypothesis that the stifle (knee) and hock (tarsal) joints could be stabilized merely with the help of a passive lock mechanism whereby the patella is secured behind a hook, formed by the medial femoral trochlea. In anaesthetized animals and isolated limbs the stifle and hock flex readily under compression. In isolated limbs this collapse was prevented by a small force applied to the patella, mimicking the action of the vastus medialis muscle. In vivo, when the limb was planted loosely on the ground none of the muscles with a connection to the patella was active. However, during weight‐bearing the vastus medialis (but no other muscle) was active, providing the necessary traction to stabilize the stifle. The required tension was estimated to be less than 2% of the force that would be needed in absence of a lock mechanism. Diagnosis and treatment of patellar fixation should include the possibility of overactive vastus medialis muscle as a possible cause of the disorder.
Immunocytochemical characteristics of elbow, knee and ankle muscles of the five‐toed jerboa (Allactaga elater)
Authors: Jouffroy F. K. , Medina M. F. , Renous S. , Gasc J.‐P.
Published: October 2010

Biochemical adaptations of limb myofibres to intensive bipedal hopping were investigated using the five‐toed jerboa Allactaga elater as a model in comparison with the rat. Immunofluorescence methods included immunoreactivity to anti‐fast and anti‐slow MHC and troponin I. There is no specialization of triceps caput mediale for postural function in the minute non‐locomotor forelimbs, unlike quadruped mammals. The various elbow extensor heads and the flexor muscles are alike with regard to fibre type population and cross‐sectional areas of each type of fibre. The extensor muscle in the elongated hindlimbs of the five‐toed jerboa, at both the knee and the ankle joints, differ from each other extensively. One head, made up of an extremely high percentage of type I, fatigue‐resistant fibres, is suited to postural function. Two extensor heads at each joint contain a very high percentage of type IIB fibres (having the greatest maximal velocity of contraction) and are able to produce the powerful acceleration needed to trigger the leap. The relative cross‐sectional areas of the myofibres are characteristic of hopping locomotion: predominance in number of one type of myofibre in a muscle accompanies greater cross‐sectional area, which increases muscle efficiency in either postural or accelerative function of the muscle.
Early GABAA receptor clustering during the development of the rostral nucleus of the solitary tract
Authors: Heck W. L. , Basaraba A. M. , Slusarczyk A. , Schweitzer L.
Published: October 2010

While there is an abundance of gamma‐aminobutyric acid (GABA) in the gustatory zone of the nucleus of the solitary tract of the perinatal rat, we know that GABAergic synapse formation is not complete until well after birth. Our recent results have shown that GABAB receptors are present at birth in the cells of the nucleus; however, they do not redistribute and cluster at synaptic sites until after PND10. The present study examined the time course of appearance and redistribution of GABAA receptors in the nucleus. GABAA receptors were also present at birth. However, in comparison to GABAB receptors, GABAA receptors underwent an earlier translocation to synaptic sites. Extrasynaptic label, for example, of GABAA receptors was non‐existent compared to GABAB receptors at PND10 and well‐defined clusters of GABAA receptors could be seen as early as PND1. We propose that while GABAA receptors may play an early neurotransmitter role at the synapse, GABAB receptors may play a non‐transmitter neurotrophic role.
Radiography of soft tissue of the foot and ankle with diffraction enhanced imaging
Authors: Li Jun , Zhong Zhong , Lidtke Roy , Kuettner Klaus E. , Peterfy Charles , Aliyeva Elmira , Muehleman Carol
Published: October 2010

Non‐calcified tissues, including tendons, ligaments, adipose tissue and cartilage, are not visible, for any practical purposes, with conventional X‐ray imaging. Therefore, any pathological changes in these tissues generally necessitate detection through magnetic resonance imaging or ultrasound technology. Until recently the development of an X‐ray imaging technique that could detect both bone and soft tissues seemed unrealistic. However, the introduction of diffraction enhanced X‐ray imaging (DEI) which is capable of rendering images with absorption, refraction and scatter rejection qualities has allowed detection of specific soft tissues based on small differences in tissue densities. Here we show for the first time that DEI allows high contrast imaging of soft tissues, including ligaments, tendons and adipose tissue, of the human foot and ankle.
Intralaryngeal neuroanatomy of the recurrent laryngeal nerve of the rabbit
Authors: Ryan Stephen , McNicholas Walter T. , O'Regan Ronan G. , Nolan Philip
Published: October 2010

We undertook this study to determine the detailed neuroanatomy of the terminal branches of the recurrent laryngeal nerve (RLN) in the rabbit to facilitate future neurophysiological recordings from identified branches of this nerve. The whole larynx was isolated post mortem in 17 adult New Zealand White rabbits and prepared using a modified Sihler's technique, which stains axons and renders other tissues transparent so that nerve branches can be seen in whole mount preparations. Of the 34 hemi‐laryngeal preparations processed, 28 stained well and these were dissected and used to characterize the neuroanatomy of the RLN. In most cases (23/28) the posterior cricoarytenoid muscle (PCA) was supplied by a single branch arising from the RLN, though in five PCA specimens there were two or three separate branches to the PCA. The interarytenoid muscle (IA) was supplied by two parallel filaments arising from the main trunk of the RLN rostral to the branch(es) to the PCA. The lateral cricoarytenoid muscle (LCA) commonly received innervation from two fine twigs branching from the RLN main trunk and travelling laterally towards the LCA. The remaining fibres of the RLN innervated the thyroarytenoid muscle (TA) and comprised two distinct branches, one supplying the pars vocalis and the other branching extensively to supply the remainder of the TA. No communicating anastomosis between the RLN and superior laryngeal nerve within the larynx was found. Our results suggest it is feasible to make electrophysiological recordings from identified terminal branches of the RLN supplying laryngeal adductor muscles separate from the branch or branches to the PCA. However, the very small size of the motor nerves to the IA and LCA suggests that it would be very difficult to record selectively from the nerve supply to individual laryngeal adductor muscles.
Immunohistochemistry of the canine vomeronasal organ
Authors: Dennis J. C. , Allgier J. G. , Desouza L. S. , Eward W. C. , Morrison E. E.
Published: October 2010

The canine's olfactory acuity is legendary, but neither its main olfactory system nor its vomeronasal system has been described in much detail. We used immunohistochemistry on paraffin‐embedded sections of male and female adult dog vomeronasal organ (VNO) to characterize the expression of proteins known to be expressed in the VNO of several other mammals. Basal cell bodies were more apparent in each section than in rodent VNO and expressed immunoreactivity to anticytokeratin and antiepidermal growth factor receptor antibodies. The thin layer of neurone cell bodies in the sensory epithelium and axon fascicles in the lamina propria expressed immunoreactivity to neurone cell adhesion molecule, neurone‐specific beta tubulin and protein gene product 9.5. Some neurones expressed growth‐associated protein 43 (GAP43): and a number of those also expressed neurone‐specific beta tubulin‐immunoreactivity. Some axon fascicles were double labelled for those two proteins. The G‐protein alpha subunits Gi and Go, involved in the signal transduction pathway, showed immunoreactivity in the sensory cell layer. Our results demonstrate that the canine vomeronasal organ contains a population of cells that expresses several neuronal markers. Furthermore, GAP43 immunoreactivity suggests that the sensory epithelium is neurogenic in adult dogs.
A study on the neutron monitoring system of LHD based on Monte Carlo simulations
Authors: Nishio N. , Yamamoto S. , Watanabe K. , Uritani A. , Isobe M. , Yamanishi H.
Published: October 2010

Neutron monitoring is quite important because fusion neutrons are a direct evidence of fusion reactions. In calibration experiments of a neutron monitoring system, Monte Carlo calculations play an important role to correct various effects. To perform Monte Carlo calculations for a helical type fusion device, we make a program that can automatically generate an input file of a helical coil geometry for the MCNP code. The neutron spatial distributions and spectra for the helical devices are calculated in the geometries automatically generated by this program. We also discuss in calibration experiments.
Formic and acetic acids in a nitrogen matrix: Enhanced stability of the higher-energy conformer
Authors: Lopes Susy , Domanskaya Alexandra V. , Fausto Rui , Räsänen Markku , Khriachtchev Leonid
Published: October 2010

Formic acid (HCOOH, FA) and acetic acid (CH3COOH, AA) are studied in a nitrogen matrix. The infrared (IR) spectra of cis and trans conformers of these carboxylic acids (and also of the HCOOD isotopologue of FA) are reported and analyzed. The higher-energy cis conformer of these molecules is produced by narrowband near-IR excitation of the more stable trans conformer, and the cis-to-trans tunneling decay is evaluated spectroscopically. The tunneling process in both molecules is found to be substantially slower in a nitrogen matrix than in rare-gas matrices, the cis-form decay constants being approximately 55 and 600 times smaller in a nitrogen matrix than in an argon matrix, for FA and AA respectively. The stabilization of the higher-energy cis conformer is discussed in terms of specific interactions with nitrogen molecule binding with the OH group of the carboxylic acid. This model is in agreement with the observed differences in the IR spectra in nitrogen and argon matrices, in particular, the relative frequencies of the νOH and τCOH modes and the relative intensities of the νOH and νCO bands.
Quantitative imaging of electronic nonuniformities in Cu(In,Ga)Se2 solar cells
Authors: Brown Gregory , Pudov Alex , Cardozo Ben , Faifer Vladimir , Bykov Eugene , Contreras Miguel
Published: October 2010

Equations describing the effect of electronic nonuniformities on electroluminescence (EL) and electron beam induced current (EBIC) images are derived and tested on Cu(In,Ga)Se2 solar cells. EL images are sensitive to fluctuations in band gap and carrier collection across a cell. EBIC images are only sensitive to variations in carrier collection allowing the two nonuniformities to be separated. Equations are derived connecting the distribution of EL intensities to the open circuit voltage loss from band gap fluctuations. Experimentally, the samples studied show the largest variation in carrier collection function on a length scale of over 100 μm while the band gap varied almost linearly across the cell. The influence of shunt, series, and stack resistances on EL images is also discussed.
Thickness-dependent local surface electronic structures of homoepitaxial SrTiO3 thin films
Authors: Ohsawa T. , Iwaya K. , Shimizu R. , Hashizume T. , Hitosugi T.
Published: October 2010

We have investigated the atomically-resolved substrate and homoepitaxial thin film surfaces of SrTiO3(001) using low-temperature scanning tunneling microscopy/scanning tunneling spectroscopy (STS) combined with pulsed laser deposition. It was found that a typical annealing treatment for preparation of SrTiO3 substrates, unexpectedly, resulted in a disordered surface on an atomic scale. In contrast, homoepitaxial SrTiO3 thin films grown on this disordered substrate exhibited a (2×2) surface reconstruction. The STS measurements revealed a number of surface defects in a 10 unit cell thick SrTiO3 film but much fewer in a 50 unit cell thick film, indicating nonuniform stoichiometry along the growth direction. These results suggest the possibility of using homoepitaxial SrTiO3 film surfaces as idealized substrates, opening a way to extract novel functionalities in complex oxides heterostructures.
Impact response of potassium bromide in 166–880 K temperature range
Authors: Favorsky V. , Zaretsky E. B.
Published: October 2010

The impact response of potassium bromide single crystals with ⟨100⟩ and ⟨110⟩ orientation was studied in a series of planar impact experiments under continuous monitoring of the sample rear surface velocity. The samples whose initial temperature varied between 166 and 880 K were loaded with aluminum, copper or tungsten impactors having velocities ranging from 140 to 690 m/s. The velocity histories recorded in the experiments with maximum compressive stress, lower than about 2 GPa, include the elastic precursor wave followed by the plastic wave, while the waveforms, recorded in the experiments with stronger loading, are characterized by a three-wave structure caused by the shock-induced B1→B2 phase transformation in KBr. On the basis of the recorded velocity histories, the temperature dependences of the shear stress τI acting at the primary glide systems of KBr, of the transformation pressure ptr, and of the characteristic transformation time ttr were determined.