bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation of scalp coverage scoring methods for scalp hair loss in male pattern hair loss (androgenetic alopecia)
Authors: Van Neste D. , Sandraps E. , Herbaut D. , Lelubre P. , Leroy T. 
Published: April 2006

Background: Global evaluation of hair loss in male subjects affected by androgenetic alopecia has been proposed as a means for monitoring changes over time, including placebo‐controlled drug efficacy studies. Because of the potential impact of subjectivity (e.g. placebo effect) of clinical investigators, global photographs (GPs) have been introduced as a more objective record. Examination of paired before and after pictures and rating on a seven‐point scale (from greatly decreased −3 to greatly increased +3) have been historically introduced by United States of America (US) experts.Methods: Based on published GPs and original GPs obtained at our clinical research facility, we developed a training set in order to allow European Union (EU) observers to practice and compare with ratings by the US experts.Results: After training with the seven‐point scale, there was a positive correlation between three US and three EU ratings (n=52 paired images from 35 different subjects, r=0.795). The results of a test–retest evaluation was performed on 18 paired images from the initial image collection by the three EU experts. Correlation r=0.806 and identical scores in 78% of cases documents a reproducibility similar to the single one US expert published data (119 subjects, retest correlation 0.76 with 75% identical duplicate ratings).Seventeen subjects taken from a placebo‐controlled trial had GPs at 6 and 12 months. The average difference between an efficacious drug treatment and the placebo were almost similar in the US (0.833) as in the EU (0.689) expert panels. We also trained the EU experts in performing the scalp coverage scoring (SCS), a novel system for the global evaluation of scalp hair in vivo and on GP. SCS was performed on single images (randomised as to time and treatment) taken from the same set of 17 paired GPs. This showed a between‐group difference of 0.055 at 6 months and 0.201 at 12 months, i.e. 5% improved coverage in favour of the active group.Conclusion: After completion of our study, US and trained ‐ calibrated EU experts seem equally valuable in comparing before–after GPs. SCS can also be used on GPs and may support the clinical investigator during inclusion of test subjects and for real‐time efficacy evaluation during the trial.
Host‐related fitness trade‐offs in a presumed generalist parasitoid, Diaeretiella rapae (Hymenoptera: Aphidiidae)
Authors: Antolin Michael F. , Bjorksten Tracey A. , Vaughn Ty T. 
Published: April 2006

Abstract.  1. Host ranges of parasitoid wasps are mediated by behavioural responses to hosts and their environment (infectivity), and development in hosts (virulence). Determinants of host range were measured in Diaeretiella rapae (Hymenoptera: Aphidiidae), which has been described as a generalist that attacks more than 60 species.2. In northern Colorado, this wasp mainly attacks two hosts: cabbage aphid (Brevicoryne brassicae) and Russian wheat aphid (Diuraphis noxia). Here, laboratory experiments are described in which D. rapae originating from these two hosts were offered several hosts for oviposition. Both infectivity and virulence were measured.3. Infectivity included host acceptance and handling time, while virulence was measured as productivity (number of progeny), survival of immatures within hosts, development time, and sex ratio.4. Wasps had higher productivity and survival when attacking ‘home’ hosts than ‘alternate’ hosts, and trade‐offs were found by quantitative genetic analyses to be genetically determined. Sex ratio and development times also showed trade‐offs, but mainly related to the host environment in which females were reared.5. In previous genetic studies in northern Colorado, populations were genetically subdivided on the scale of 1 km. The fitness differences described here could be strong enough to create populations adapted to different hosts, but it appears that gene flow is sufficient to prevent formation of separate lineages on the two hosts.6. Rather than being a generalist with a broad host range, D. rapae is a serial specialist, attacking particular hosts according to availability in different seasons or in different geographical areas.
Heterogeneous distribution may substantially decrease initial decomposition, long‐term microbial growth and N‐immobilization from high C‐to‐N ratio resources
Authors: Magid J. , De Neergaard A. , Brandt M. 
Published: April 2006

SummaryThe effect of heterogeneous resource distribution in soil has seldom been studied under controlled laboratory conditions, even though this type of distribution is the rule rather than the exception in both agricultural and undisturbed soil systems. We use distribution trials to test the effect of stratified distribution of chopped maize, sheep faeces derived from maize, and chopped rape stems compared with even distribution. In all treatments, CO2 mineralization decreased initially in the stratified experiments and in the rape treatment less (39 versus 43%) of the added carbon was mineralized even after 202 days of incubation at 15°C. In both maize and rape residue treatments, we observed much less immobilization of Nmin and less microbial growth in the stratified experiments. The data set for rape was sufficiently detailed to allow a model interpretation using a spreadsheet version of the soil organic matter module from DAISY, a soil‐plant‐atmosphere system model. This indicated that the observed differences between the stratified and evenly distributed experiments could be largely understood by assuming diffusion limitation of nitrate from the bulk soil to the residuesphere. The residuesphere is the part of soil that is immediately affected by the decomposition of residue, and was assumed to be included in the first 10 mm of soil surrounding the residues in the stratified experiments at all times. Only a very small part of the variation in CO2 respiration, Nmin and soil microbial biomass N (SMB‐N) could be explained by additionally assuming less substrate utilization efficiency of the less decomposable fraction of rape in the stratified experiment. We observed greater N mineralization in the evenly distributed experiment with faeces, and smaller concentrations of soil microbial biomass nitrogen extracted by chloroform fumigation. We assume that most of the additional SMB‐N determined in the faeces treatments was from microorganisms present in the faeces at the time they were added to soil, and that these were less susceptible to microbial predation in the stratified than in the distributed experiment. We conclude that the spatial distribution of decomposing litters in soil significantly affects the C and N dynamics. Diffusion limitation of available N in the active zone of decomposition was the main causal agent, which induced a decrease in microbial growth and substrate utilisation.
Annual cycle of clupeiform larvae around Gran Canaria Island, Canary Islands
Authors: BÉCOGNÉE P. , ALMEIDA C. , BARRERA A. , HERNÁNDEZ‐GUERRA A. , HERNÁNDEZ‐LEÓN S. 
Published: April 2006

AbstractThe distribution and abundance of fish larvae was studied along the eastern and southern shelf of Gran Canaria Island (Canary Islands) from July 2000 to June 2001. Oblique bongo hauls were carried out fortnightly during the daytime, coinciding with days of full and new moon. During February, the area was sampled every 2–5 days. About 17.3% of the ichthyoplanktonic community was composed of clupeiform larvae: 92.9% of these larvae were Sardinella aurita, whereas 4.7% and 2.4% were respectively Engraulis encrasicolus and Sardina pilchardus. Sardinella aurita larvae appeared during the whole year with two periods of maximum abundance: June to September and December to February. During the full moon their abundance was on average 38.5% (±6.8%) of their numbers during the new moon, showing a clear lunar periodicity. Engraulis encrasicolus larvae appeared from November to March, also coinciding with the new moon. Sardina pilchardus larvae only appeared during two short periods, both coinciding with filaments shed from the African coastal upwelling which reached the island. This fact confirms the transport of fish larvae from the upwelling area off northwest Africa to the Canary Islands, promoting a genetic flow among both sites.
Dynamical effects of the statistical structure of annual rainfall on dryland vegetation
Authors: WILLIAMS CHRISTOPHER A. , ALBERTSON JOHN D. 
Published: April 2006

AbstractIn this study, we extend a model of daily dryland dynamics by parameterizing a modified version of a minimalistic annual model to examine how the statistical structure of annual rainfall and grazing intensity interact to influence dryland vegetation. With a Monte Carlo approach, an ensemble outcome provides a statistical description of likely dryland vegetation dynamics responding to variations in rainfall structure and grazing intensity. Results suggest that increased rainfall variability decreases the average and increases the variability of grass cover leading to more frequent degradation of the grass resource. Vegetation of drier regions is found to be more sensitive to interannual variability in rainfall. Concentrating this variability into an organized periodic mode further decreases the mean and increases the variability of grass cover. Hence, a shift toward lower, more variable, or more inter‐annually correlated annual rainfall will likely lead to a general decrease in the grass resource and increased dryland vulnerability to degradation.Higher grazing intensity or lower annual rainfall both lead to more frequent and longer duration degradation of the grass condition. We note an interesting interaction in the response of grass biomass to grazing intensity and rainfall variability, where increased rainfall variability leads to longer duration degradation for low grazing, but shorter periods of degradation for high grazing. Once grass reaches a degraded condition, we find that woody vegetation strongly suppresses recovery even if successive rainfall is high. Overall, these findings suggest that the projected increase in interannual rainfall variability will likely decrease grass cover and potentially lead to more frequent, longer lasting degradation of dryland vegetation, particularly if enhanced rainfall variability is concentrated in long period (e.g. decadal) modes.
Importance of recent shifts in soil thermal dynamics on growing season length, productivity, and carbon sequestration in terrestrial high‐latitude ecosystems
Authors: EUSKIRCHEN E. S. , McGUIRE A. D. , KICKLIGHTER D. W. , ZHUANG Q. , CLEIN J. S. , DARGAVILLE R. J. , DYE D. G. , KIMBALL J. S. , McDONALD K. C. , MELILLO J. M. , ROMANOVSKY V. E. , SMITH N. V. 
Published: April 2006

AbstractIn terrestrial high‐latitude regions, observations indicate recent changes in snow cover, permafrost, and soil freeze–thaw transitions due to climate change. These modifications may result in temporal shifts in the growing season and the associated rates of terrestrial productivity. Changes in productivity will influence the ability of these ecosystems to sequester atmospheric CO2. We use the terrestrial ecosystem model (TEM), which simulates the soil thermal regime, in addition to terrestrial carbon (C), nitrogen and water dynamics, to explore these issues over the years 1960–2100 in extratropical regions (30–90°N). Our model simulations show decreases in snow cover and permafrost stability from 1960 to 2100. Decreases in snow cover agree well with National Oceanic and Atmospheric Administration satellite observations collected between the years 1972 and 2000, with Pearson rank correlation coefficients between 0.58 and 0.65. Model analyses also indicate a trend towards an earlier thaw date of frozen soils and the onset of the growing season in the spring by approximately 2–4 days from 1988 to 2000. Between 1988 and 2000, satellite records yield a slightly stronger trend in thaw and the onset of the growing season, averaging between 5 and 8 days earlier. In both, the TEM simulations and satellite records, trends in day of freeze in the autumn are weaker, such that overall increases in growing season length are due primarily to earlier thaw. Although regions with the longest snow cover duration displayed the greatest increase in growing season length, these regions maintained smaller increases in productivity and heterotrophic respiration than those regions with shorter duration of snow cover and less of an increase in growing season length. Concurrent with increases in growing season length, we found a reduction in soil C and increases in vegetation C, with greatest losses of soil C occurring in those areas with more vegetation, but simulations also suggest that this trend could reverse in the future. Our results reveal noteworthy changes in snow, permafrost, growing season length, productivity, and net C uptake, indicating that prediction of terrestrial C dynamics from one decade to the next will require that large‐scale models adequately take into account the corresponding changes in soil thermal regimes.
Variations in satellite‐derived phenology in China's temperate vegetation
Authors: PIAO SHILONG , FANG JINGYUN , ZHOU LIMING , CIAIS PHILIPPE , ZHU BIAO 
Published: April 2006

AbstractThe relationship between vegetation phenology and climate is a crucial topic in global change research because it indicates dynamic responses of terrestrial ecosystems to climate changes. In this study, we investigate the possible impact of recent climate changes on growing season duration in the temperate vegetation of China, using the advanced very high resolution radiometer (AVHRR)/normalized difference vegetation index (NDVI) biweekly time‐series data collected from January 1982 to December 1999 and concurrent mean temperature and precipitation data. The results show that over the study period, the growing season duration has lengthened by 1.16 days yr−1 in temperate region of China. The green‐up of vegetation has advanced in spring by 0.79 days yr−1 and the dormancy delayed in autumn by 0.37 days yr−1. The dates of onset for phenological events are most significantly related with the mean temperature during the preceding 2–3 months. A warming in the early spring (March to early May) by 1°C could cause an earlier onset of green‐up of 7.5 days, whereas the same increase of mean temperature during autumn (mid‐August through early October) could lead to a delay of 3.8 days in vegetation dormancy. Variations in precipitation also influenced the duration of growing season, but such influence differed among vegetation types and phenological phases.
A rapid altitudinal range expansion in the pine processionary moth produced by the 2003 climatic anomaly
Authors: BATTISTI ANDREA , STASTNY MICHAEL , BUFFO EMILIANO , LARSSON STIG 
Published: April 2006

AbstractClimatic anomalies may produce, or accelerate, geographic range expansions of species limited by temperature or other climatic variables. Most such expansions are only temporary, before the prevailing climatic conditions drive the founder populations extinct. In contrast, here, we report a recent rapid shift of the range limit during the record hot summer of 2003 in southern Europe that has the potential to be both permanent, and to have important implications on species range dynamics in general. The winter pine processionary moth (Thaumetopoea pityocampa), an important pine defoliator whose larvae feed in colonies during the winter, is limited in its distribution by winter temperatures. In the last three decades, warmer winters have led to a gradual but substantial expansion of its range both latitudinally and altitudinally. In the summer of 2003,T. pityocampaunderwent an extraordinary expansion to high elevation pine stands in the Italian Alps; its altitudinal range limit increased by one third of the total altitudinal expansion over the previous three decades. In an experiment, we found flight activity of newly emerged females to increase with temperature. By determining a threshold temperature for flight take‐offs under controlled conditions, we calculated that the nights above the threshold temperature were over five times more frequent, and considerably warmer, at the range limit in 2003 than in an average year. We therefore attribute the colonization of extreme, high‐elevation sites to increased nocturnal dispersal of females during the unusually warm night temperatures in June – August 2003. Importantly, the colonies established at extreme sites survived the winter and produced offspring in 2004, although the range did not expand further because of low night temperatures that year. We discuss several life‐history characteristics ofT. pityocampathat maximize the likelihood of population persistence at the new range limit. As global warming continues and climatic anomalies are predicted to become more frequent, our results draw attention to the importance of extreme climatic events in the range formation of phytophagous insects.
Life‐history traits of lake plankton species may govern their phenological response to climate warming
Authors: ADRIAN RITA , WILHELM SUSANN , GERTEN DIETER 
Published: April 2006

AbstractA prominent response of temperate aquatic ecosystems to climate warming is changes in phenology – advancements or delays in annually reoccurring events in an organism's life cycle. The exact seasonal timing of warming, in conjunction with species‐specific life‐history events such as emergence from resting stages, timing of spawning, generation times, or stage‐specific prey requirements, may determine the nature of a species' response. We demonstrate that recent climate‐induced shifts in the phenology of lake phytoplankton and zooplankton species in a temperate eutrophic lake (Müggelsee, Germany) differed according to differences in their characteristic life cycles. Fast‐growing plankton in spring (diatoms, Daphnia) showed significant and synchronous forward movements by about 1 month, induced by concurrent earlier ice break‐up dates (diatoms) and higher spring water temperature (Daphnia). No such synchrony was observed for slow‐growing summer zooplankton species with longer and more complex life cycles (copepods, larvae of the mussel Dreissena polymorpha). Although coexisting, the summer plankton responded species specifically to seasonal warming trends, depending on whether the timing of warming matched their individual thermal requirements at decisive developmental stages such as emergence from diapause (copepods), or spawning (Dreissena). Others did not change their phenology significantly, but nevertheless, increased in abundances. We show that the detailed seasonal pattern of warming influences the response of phyto‐ and zooplankton species to climate change, and point to the diverse nature of responses for species exhibiting complex life‐history traits.
Agrarian legacy in soil nutrient pools of urbanizing arid lands
Authors: LEWIS DAVID BRUCE , KAYE JASON P. , GRIES CORINNA , KINZIG ANN P. , REDMAN CHARLES L. 
Published: April 2006

AbstractToday's worldwide expansion of dry land cities consumes cultivated and native ecosystems, providing laboratories for investigating imprints of former land use in places where people now live. Around Phoenix, USA, we compared soil nutrient pools in residential yards converted from farms with nutrient pools in yards developed on native desert. Organic matter, carbon (C), nitrogen (N), and soluble ions were >2‐fold greater in yards that were previously agrarian than in yards that were not. These pools remain elevated 40 years after land conversion to residential use. Present N accumulation (1.5 g m−2 yr−1) is not affected by prior land use, suggesting that rates of residential fertilizer application and retention are not affected by antecedent soil fertility. Bioavailable, inorganic phosphorus (Pav) is elevated in soil with a recent agrarian past, but this signal disappears after 10–30 years of residential use owing to an accumulation of Pav in never‐farmed yards. Our results indicate a ‘direct agrarian legacy,’ wherein agrarian amendment of nutrient pools endures urbanization, more so than an ‘indirect legacy,’ wherein present land management is molded by former land use. Agriculture in dry lands thus sequesters material in soils, and—as we also found higher material contents in residential soils than in contemporary agrarian soils—residential land use simply adds to the agrarian legacy these soils already bear. Intense human use of arid lands may cause increases in material pools in soils, a condition with potential global consequence.
Freshwater food webs control carbon dioxide saturation through sedimentation
Authors: FLANAGAN KYLA M. , MCCAULEY EDWARD , WRONA FREDERICK 
Published: April 2006

AbstractCarbon cycling in lakes has been studied both in terms of the magnitude and global significance of carbon released to the atmosphere and carbon stored in the sediments. Interestingly, to the best of our knowledge there have been no studies examining whether instantaneous measures of carbon flux are directly related to how much carbon is being drawn down to the sediments. Here, we show that the saturation of CO2 in the water column is negatively related to the sedimentation rate. We, therefore, suggest that sedimentation should be explicitly considered as a factor directly controlling CO2 flux from freshwaters. Furthermore, we show that food webs and nutrients can alter CO2 flux by changing sedimentation. Oceanographers have long recognized the interaction between biota and sedimentation in the carbon dynamics of the ocean, a mechanism referred to as the biological pump. Our experiments rigorously test sedimentation and food web structure as factors controlling CO2 saturation and suggest a common framework for freshwater and marine systems.
A stable isotopic investigation into the causes of decline in a sub‐Antarctic predator, the rockhopper penguin Eudyptes chrysocome
Authors: HILTON GEOFF M. , THOMPSON DAVID R. , SAGAR PAUL M. , CUTHBERT RICHARD J. , CHEREL YVES , BURY SARAH J. 
Published: April 2006

AbstractThe rockhopper penguin (Eudyptes chrysocome) is a conspicuous apex marine predator that has experienced marked population declines throughout most of its circumpolar breeding distribution. The cause(s) for the declines remain elusive, but the relatively large spatio‐temporal scale over which population decreases have occurred implies that ecosystem‐scale, at‐sea factors are likely to be involved. We employ stable isotope analyses of carbon (13C/12C, expressed as δ13C) and nitrogen (15N/14N, δ15N) in time‐series of rockhopper penguin feather samples, dating back to 1861, in order to reconstruct the species' ecological history. Specifically, we examine whether rockhopper penguin population decline has been associated with a shift towards lower primary productivity in the ecosystem in which they feed, or with a shift to a diet of lower trophic status and lower quality, and we use long‐term temperature records to evaluate whether shifts in isotope ratios are associated with annual variations in sea surface temperature. Having controlled temporally for the Suess Effect and for increases in CO2 concentrations in seawater, we found that overall, δ13C signatures decreased significantly over time in rockhopper penguins from seven breeding sites, supporting the hypothesis that decreases in primary productivity, and hence, carrying capacity, for which δ13C signature is a proxy, have been associated with the decline of penguin populations. There was some evidence of a long‐term decline in δ15N at some sites, and strong evidence that δ15N signatures were negatively related to sea surface temperatures across sites, indicative of a shift in diet to prey of lower trophic status over time and in warm years. However, a site‐by‐site analysis revealed divergent isotopic trends among sites: five of seven sites exhibited significant temporal or temperature‐related trends in isotope signatures. This study highlights the utility of stable isotope analyses when applied over relatively long timescales to apex predators.