bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reconstructed summer temperature in the northern Rocky Mountains wilderness, USA
Authors: Kipfmueller Kurt F. 
Published: June 2008

AbstractRing widths from whitebark pine (Pinus albicaulisEnglem.) and subalpine larch (Larix lyalliiParl.) collected at three high-elevation sites were used to develop tree-growth chronologies to reconstruct summer temperature anomalies. A step-wise multiple regression procedure was used to screen potential predictor variables to generate a transfer function capable of skillfully reconstructing summer temperature. The resulting regression model explained approximately 38% of the adjusted variance in the instrumental temperature record. The fidelity of the reconstruction was verified using product mean and sign tests, both of which suggested significant predictive power in the reconstructions (p<0.05). Reduction of error (RE) and coefficient of efficiency (CE) measures were both positive, indicating the reconstruction contained useful climate information. Cool periods often coincided with reduced solar activity and/or periods of increased volcanic activity. Differences between this reconstruction and others encompassing a broader geographic scale highlight the importance of developing local reconstructions of climate variability, particularly when used in conjunction with ecological data sets that describe the occurrence of fires or insect epidemics. Mixed and divergent climate-response relationships were evident in the whitebark pine chronologies and suggest subalpine larch may be a more useful species than whitebark pine to target for the development of temperature reconstructions in this region.
Sand dunes as a major proximal dust source for late Pleistocene loess in the Negev Desert, Israel
Authors: Crouvi Onn , Amit Rivka , Enzel Yehouda , Porat Naomi , Sandler Amir 
Published: June 2008

AbstractGrain size analyses of three hilltop, primary eolian loess sequences in the Negev desert, southern Israel, show a bimodal grain-size distribution at 50–60 μm and 3–8 μm. Using analyses of mineralogy and OSL ages we demonstrate that the coarse mode is composed mostly of quartz grains and its relative magnitude increases regionally with time, suggesting an enhancement of a time-transgressive proximal dust source compared to a distal, Saharan fine-grain dust. The only proximal dust source for large amount of coarse silt quartz grains is the sands that advanced into Sinai and the Negev concurrently with the loess accretion during the late Pleistocene as a result of the exposure of the Mediterranean shelf. We therefore propose that the coarse silt quartz grains were formed through eolian abrasion within the margins of an advancing sand sea. This relationship between desert sand seas as a source for proximal coarse dust and desert margin loess deposits can be applicable to other worldwide deserts such as Northern Africa, China and Australia.
Chronology and causes of the extinction of the Lava Mouse,Malpaisomys insularis(Rodentia: Muridae) from the Canary Islands
Authors: Rando Juan Carlos , Alcover Josep Antoni , Navarro Juan Francisco , García-Talavera Francisco , Hutterer Rainer , Michaux Jacques 
Published: June 2008

AbstractUnderstanding late Holocene extinctions on islands requires accurate chronologies for all relevant events, including multiple colonisations by humans and the introduction of alien species. The most widely held hypothesis on the causes of Holocene island vertebrate extinctions incorporates human impacts, although climatic-related hypotheses cannot be excluded. Both hypotheses have been suggested to account for the extinction of the endemic Lava Mouse,Malpaisomys insularisfrom the Canary Islands. Here we present the first accelerator mass spectrometer (AMS)14C ages from collagen ofM. insularisbones from ancient owl pellets collected at Fuerteventura (Canary Islands, eastern Atlantic Ocean). These new dates contribute to an understanding of the extinction of this species. We are able to exclude climatic causes, predation by invasive species, and competition with the house mouse,Mus musculus. The arrival of Europeans in the Canary Islands correlates with the extinction ofMalpaisomys. The introduction of rats,Rattusspp., together with their parasites and diseases, emerges as the most reasonable hypothesis explaining the extinction ofM. insularis.
Cariogenic potential of cows', human and infant formula milks and effect of fluoride supplementation
Authors: Peres Regina Celia Rocha , Coppi Luciane Cristina , Volpato Maria Cristina , Groppo Francisco Carlos , Cury Jaime Aparecido , Rosalen Pedro Luiz 
Published: June 2008

The aim of the present study was to evaluate the cariogenicity of cows', human and infant formula milks, supplemented or not with fluoride, in rats. Sixty female Wistar rats were desalivated and infected withStreptococcus sobrinus6715.Animals were divided into six groups: group 1, sterilised deionised distilled water (SDW; negative control); group 2, 5 % sucrose added to SDW (positive control); group 3, human milk; group 4, cows' milk; group 5, Ninho®formula reconstituted with SDW; group 6, Ninho®formula reconstituted with 10 parts per million F and SDW. At day 21 the animals were killed and their jaws removed to quantify total cultivable microbiota,Strep. sobrinusand dental caries. The concentration of carbohydrate and fluoride in the milks was analysed. The Kruskal–Wallis test (α = 5 %) was used to analyse the data. The caries score by the milk formula was as high as that provoked by sucrose. Regarding smooth-surface caries, human milk was statistically more cariogenic than cows' milk, which did not differ from the SDW and the Ninho®with fluoride (P>0·05). Groups 2–6 showed higherStrep. sobrinuscounts when compared with the negative control group (P < 0·05) but no statistically significant difference was found among them (P>0·05). HPLC analysis showed that infant formula had 9·3 % sucrose and 3·6 % reducing sugars. The infant formula should be considered cariogenic due to the sugars found in it, but fluoride supplementation reduced its cariogenic effect. The human milk was more cariogenic than the cows' milk but not as much as the formula milk.
Contamination of fox hair with eggs ofToxocara canis
Authors: Roddie G. , Holland C. , Stafford P. , Wolfe A. 
Published: June 2008

AbstractEighty-seven red foxes were investigated for the presence ofToxocaraeggs on a sample of their hair from the peri-anal region. The worm burden ofToxocarain each fox intestine was also assessed and the relationship between eggs on the hair and worms in the intestine explored. Twenty-eight per cent of the foxes were found to haveToxocaraeggs on their hair, with an average of 1.31 ± 3.21 eggs per gram of hair ( ± SD). Sixty-one per cent of foxes harbouredToxocaraworms within their intestines, with a mean worm burden ( ± SD) of 4 ± 8. Host age and sex did not significantly influence the observed eggs on the hair or the worm burden. No significant correlation was found between the numbers of eggs on the hair and the worm burden within the intestine. These data collected from foxes are explored in the context of data from stray dogs and the possible epidemiological differences are discussed.
Food of the yellowtail amberjack Seriola lalandi from the south-west Atlantic
Authors: Vergani M. , Acha E.M. , de Astarloa J.M. Diaz , Giberto D. 
Published: June 2008

Food of Seriola lalandi was mainly composed of juveniles of horse mackerel (Trachurus lathami) (%IRI = 99.66) showing the species as carnivorous feeders predating on small pelagic organisms.
Age and growth of the common guitarfish, Rhinobatos rhinobatos, in Iskenderun Bay (north-eastern Mediterranean, Turkey)
Authors: Başusta Nuri , Demirhan Sefa Ayhan , Çiçek Erdoğan , Başusta Asiye , Kuleli Tuncay 
Published: June 2008

Age and growth of the common guitarfish (Rhinobatos rhinobatos) were estimated from the north-eastern Mediterranean coast of Turkey. A total of 115 common guitarfish (66 females and 49 males) were sampled. Age determinations were carried out using vertebral sections. Alcian blue dying techniques were used to enhance the visibility of the band on vertebrae. The techniques have been used for the first time on elasmobranchs vertebrae successfully in this study. A total of 97 vertebrae of 115 were visible on the vertebral band in this study. Male and female common guitarfish ranged in age from 1 to 15 and 1 to 24 y respectively. Total length ranged from 42 to 147 cm for females and 39 to 124 cm for males.The relationships between total length (TL) and total weight (TW) were presented as TW = 0.0014*TL3.1672 (R2 = 0.98) for females, TW = 0.0012*TL3.1947 (R2 = 0.98) for males and TW = 0.0012*TL3.1915 (R2 = 0.98) for both sexes. The parameters for von Bertalanffy growth curves were estimated as Linf = 137.70±9.38 cm, K = 0.159±0.047, to = −2.180 ± 0.90 for pooled data.
Slow recovery from disturbance: a 20 year study of Ascophyllum canopy clearances
Authors: Ingólfsson A. , Hawkins S.J. 
Published: June 2008

We describe an experiment where Ascophyllym nodosum was removed from two 1 x 1 m plots in south-western Iceland in August 1985. The plots were studied regularly until 2005. Recovery of the Ascophyllum canopy took 7–8 years. The understorey algae in one of the plots consisted mostly of extensive growth of Cladophora rupestris, which died within a year of Ascophyllum clearance. No Cladophora had reappeared by 2005, although it was healthy and abundant in control plots throughout the study period. Thus even after 20 years the community had not recovered from disturbance.
Leptogorgia christiae (Octocorallia: Gorgoniidae) a new shallow water gorgonian from Pacific Panama
Authors: Guzman Hector M. , Breedy Odalisca 
Published: June 2008

Leptogorgia christiae is a rarely collected new species found at 15–30 m depth at Roca Hacha, a rocky outcrop near Coiba Island characterized by its high diversity of octocorals. The branching pattern and combination of asymmetric blunt spindles, abundance of capstans, and a low occurrence of acute spindles are distinct characteristics of the new taxon. The new species is described, illustrated and compared to the other species of the genus reported from Pacific Panama; thus increasing the total of Leptogorgia species to 17, which encompasses over 70% of the shallow water species for the eastern Pacific.
Temporal patterns of phytoplankton assemblages, size spectra and diversity during the wane of aPhaeocystis globosaspring bloom in hydrologically contrasted coastal waters
Authors: Schapira Mathilde , Vincent Dorothee , Gentilhomme Valerie , Seuront Laurent 
Published: June 2008

The space–time dynamic of phytoplankton diversity and succession was investigated during the wane of aPhaeocystis globosaspring bloom in four distinct hydrological sub-systems of the eastern English Channel. Nutrients, chlorophyll-a concentrations, and phytoplankton composition, standing stocks, size spectra and diversity were monitored during three key periods in 2003: late spring, early summer and summer. Two consecutive diatom assemblages were observed, respectively dominated by: (i) small colonial species (<100 μm;Melosirasp.,Diploneissp. andNavicula transitans) in April; and (ii) large fine-walled cells (>200 μm;Guinardia striataandRhizosolenia imbricata) in May and July. This shift in diatom composition appeared to be related to the potentially limitating silicic acid in early summer. Specific phytoplankton assemblages identified in distinct water masses have evolved from a mature/senescent community towards a relatively homogeneous aestival structure of dominant species that might have been triggered by the wane of theP. globosabloom. Our results also identified a strong heterogeneity in the distribution of secondary species between distinct water masses during the summer period, suggesting that the magnitude of the observed patterns was intrinsically related to the hydrological properties prevailing in each sub-system. The identification of distinct temporal patterns in phytoplankton species diversity and succession following the wane of a spring bloom at relatively small spatial scales (i.e. <10 km) is discussed in the framework ofP. globosablooms in particular and phytoplankton blooms in general and is suggested to have potentially strong consequences on food web dynamics and the carbon cycle in coastal ecosystems.
Trophic organization of the macro-zoobenthic assemblages within coastal areas subjected to anthropogenic activities
Authors: Afli Ahmed , Ayari Rakia , Brahim Mouldi 
Published: June 2008

Coastal areas, in general, are affected more and more by anthropogenic activities. Benthic macrofauna assemblages react to this disturbance and constitute, then, an effective biological tool to study the degree of contamination of the biotope. For this study three coastal sites, more or less exposed to anthropogenic activities but differing according to their opening to the sea, were studied. Sediments were sampled aboard a research vessel and using a 0.1 m2 Van Veen grab. Results show that Tunis bay and Dkhila coast, which are more open to the sea, appear more balanced on the trophic plan, and the biodiversity state is more satisfactory. However, Bizerte lagoon is closed, except for a limited communication with the sea via a narrow ship canal. So, the ecosystem presents some eutrophication signs and a great trophic imbalance in which carnivores largely dominate the benthic assemblages. In this situation, the herbivore chain is substituted by a microbial chain and only some opportunistic species can survive in these anoxic sediments related to the strong fluctuations of the environment factors during the year.
Diet composition and food habits of Caranx rhonchus (Carangidae) from the Gulf of Gabes (central Mediterranean)
Authors: Sley Ayda , Jarboui Othman , Ghorbel Mohamed , Bouain Abderrahmen 
Published: June 2008

From June 2004 to May 2006, 1040 Caranx rhonchus (Carangidae) ranging from 6.5 to 30.6 cm in total length (TL), fished in the Gulf of Gabes (south Tunisia, central Mediterranean), were used to investigate feeding habits of the species. This study was based mainly on the evolution of the index of relative importance (IRI) with respect to sex, fish size and season. Among 1040 stomachs examined, 595 were empty (%VI = 57.2). The vacuity index (%VI) differed significantly across months and declined slightly with season. A total of 13 species representing 12 different families belonging to four major groups: teleosts, crustaceans, molluscs and annelids, were identified in stomach contents of Caranx rhonchus.Caranx rhonchus is primarily an opportunistic piscivorous fish with a diet characterized by a wide range of species. Teleosts occurred in the majority of stomachs, with a total of the relative importance (%IRI) of 52.7%. The anchovy Engraulis encrasicolus were the most important teleost species (%IRI = 11.2), while crustaceans were the second most important food category consumed (47.1%).There were no significant differences in the diet between males and females, but significant differences were found with season and among size-classes.
Natural egg mass deposition by the Humboldt squid (Dosidicus gigas) in the Gulf of California and characteristics of hatchlings and paralarvae
Authors: Staaf Danna J. , Camarillo-Coop Susana , Haddock Steven H.D. , Nyack Al C. , Payne John , Salinas-Zavala Cesar A. , Seibel Brad A. , Trueblood Lloyd , Widmer Chad , Gilly William F. 
Published: June 2008

The jumbo or Humboldt squid, Dosidicus gigas, is an important fisheries resource and a significant participant in regional ecologies as both predator and prey. It is the largest species in the oceanic squid family Ommastrephidae and has the largest known potential fecundity of any cephalopod, yet little is understood about its reproductive biology. We report the first discovery of a naturally deposited egg mass of Dosidicus gigas, as well as the first spawning of eggs in captivity. The egg mass was found in warm water (25–27°C) at a depth of 16 m and was far larger than the egg masses of any squid species previously reported. Eggs were embedded in a watery, gelatinous matrix and were individually surrounded by a unique envelope external to the chorion. This envelope was present in both wild and captive-spawned egg masses, but it was not present in artificially fertilized eggs. The wild egg mass appeared to be resistant to microbial infection, unlike the incomplete and damaged egg masses spawned in captivity, suggesting that the intact egg mass protects the eggs within. Chorion expansion was also more extensive in the wild egg mass. Hatchling behaviours included proboscis extension, chromatophore activity, and a range of swimming speeds that may allow them to exercise some control over their distribution in the wild.
Distribution and morphological variation of colonies of the bryozoan Pentapora fascialis (Bryozoa: Cheilostomata) along the western coast of Italy
Authors: Lombardi C. , Cocito S. , Occhipinti-Ambrogi A. , Porter J.S. 
Published: June 2008

Bathymetric range, substrate, colony density, colony size, and some zoarial features (form of the colony and branches) of the carbonate reef building cheilostome bryozoan Pentapora fascialis (Pallas) were recorded from 15 localities along the western coast of Italy. A wide range in the depth distribution of colonies was observed (11 to 60 m). Colonies occurred on several different types of substrate including gorgonians, sponges, bedrock and rock boulders, in current swept areas. Density was approximately 1 colony/m2. The most frequent colony size-class was 10 to 20 cm in diameter and was typically found growing epizoically on gorgonians. Ellipsoidal colony forms with expanded, foliaceous laminae were characteristic of larger colonies; these frequently grew on rock substrates. Subspherical colonies with a diameter less than 20 cm grew as epizoans and had a narrow branches structure. This information will help to inform decisions on taxonomic discrepancies within the Pentaporidae. In addition the data provide a useful baseline for the future estimation of a carbonate budget in the region.
A diplexer for gigawatt class high power microwaves
Authors: Li G. L. , Yuan C. W. , Zhang J. Y. , Shu T. , Zhang J. 
Published: June 2008

AbstractWith the rapid development of high power microwave (HPM) technologies, HPM devices with several output frequencies are becoming more and more attractive. Diplexer is a microwave device with two output frequencies, here, an L/X band diplexer with novel structure is tried to be employed in the HPM system. In order to obtain the same radiation direction for the L and X band microwaves in the diplexer, the reflection of L band microwaves and transmission of X band microwaves are realized by an array of irises. To obtain the required performance, the width and thickness of the irises and the distance between them should be well chosen. The diplexer is investigated through theoretical analysis and numerical computation, and the final design described in this work, is the result of an overall optimization process. In simulation, both the reflectivities of L-band microwaves and the transmissivities of X band microwaves reach 99.5%, and the power handling capacity of the diplexer is higher than 5.6 gigawatt (GW). Then, the L/X band diplexer is designed and fabricated according to the optimized results. After that, a series of experiments are carried out to test the diplexer. The cold test results show that the reflectivities of L band microwaves are as high as 97.5%, and the transmissivities of X band microwaves are up to 98.8%, and the acquired radiation patterns show that the designed diplexer is suitable for the diplexing of L/X band microwaves, in a word, the cold test results of the diplexer are in good agreement with the simulational results. In the end, the diplexer is tested with GW class HPMs. The radiated HPMs have little change in the pulse duration and magnitude with the diplexer applied, that is to say, there is no microwave breakdown during the HPM reflection and transmission.
Genetic algorithm-based optimal bipedal walking gait synthesis considering tradeoff between stability margin and speed
Authors: Dip Goswami , Prahlad Vadakkepat , Kien Phung Duc 
Published: June 2008

SUMMARYThe inverse kinematics of a 12 degrees-of-freedom (DOFs) biped robot is formulated in terms of certain parameters. The biped walking gaits are developed using the parameters. The walking gaits are optimized using genetic algorithm (GA). The optimization is carried out considering relative importance of stability margin and walking speed. The stability margin depends on the position of zero-moment-point (ZMP) while walking speed varies with step-size. The ZMP is computed by an approximation-based method which does not require system dynamics. The optimal walking gaits are experimentally realized on a biped robot.
Analysis and mapping of the orientation error of a 3-DOF translational parallel manipulator
Authors: Affi Zouhaier , Romdhane Lotfi 
Published: June 2008

SUMMARYThis paper deals with the computation of the orientation error and the kinematic model of a 3-DOF translational parallel manipulator called the RAF robot. We derived a simple analytical model allowing the computation of the orientation, generated by the deformation of the PKLs, when an external load is applied to the platform. These models allowed us to map the orientation error on the workspace of the robot. We showed in particular that the minimum orientation error can be obtained when the platform is in a certain region of its workspace. Due to its analytical nature, the developed model can also be used for a sensitivity analysis in order to maximize the manipulator precision.
Firn depth correction along the Antarctic grounding line
Authors: van den Broeke Michiel , van de Berg Willem Jan , van Meijgaard Erik 
Published: June 2008

AbstractTo reduce the uncertainty in the calculation of Antarctic solid ice fluxes, the firn depth correction (Δh) in Antarctica is inferred from a steady-state firn densification model forced by a regional atmospheric climate model. The modelled density agrees well with observations from firn cores, apart from a site at the origin of fast flowing West Antarctic ice stream (Upstream B), where densification is anomalously rapid. The spatial distribution of Δh over Antarctica shows large variations, especially in the grounding line zone where large climate gradients exist. In places where the grounding line crosses ablation areas, Δh is zero. Along the remainder of the grounding line, Δh values range from typically 13 m in dry coastal areas (e.g. Dronning Maud Land) to 19 m in wet coastal areas (e.g. West Antarctica).
Introduction: A Peaceful Europe? Negotiating Peace in the Twentieth Century
Authors: NEHRING HOLGER , PHARO HELGE 
Published: June 2008

AbstractThe introduction to this special issue on peace in twentieth-century Europe develops a novel interpretation of twentieth-century European history. Rather than focusing on the question of the impact of war and violence within European societies, it seeks to examine what we can gain from exploring how peace was established and maintained in the wake of wars in various European societies. In particular, it focuses on the manifold ways in which different social and international actors negotiated peace, both literally and symbolically. Taken together, the contributions to this special issue thus present a much more complex picture of twentieth-century Europe than the one of a ‘Dark Continent’ (Mark Mazower) ravaged by violence or that propagated by European institutions of a peaceful Europe.