bluuebunny/crossref_metadata_2025_split huggingface dataset:
Slow recovery of High Arctic heath communities from nitrogen enrichment
Authors: Street Lorna E. , Burns Nancy R. , Woodin Sarah J. 
Published: January 2015

Summary

Arctic ecosystems are strongly nutrient limited and exhibit dramatic responses to nitrogen (N) enrichment, the reversibility of which is unknown. This study uniquely assesses the potential for tundra heath to recover from N deposition and the influence of phosphorus (P) availability on recovery.

We revisited an experiment in Svalbard, established in 1991, in which N was applied at rates representing atmospheric N deposition in Europe (10 and 50 kg N ha−1 yr−1; ‘low’ and ‘high’, respectively) for 3–8 yr. We investigated whether significant effects on vegetation composition and ecosystem nutrient status persisted up to 18 yr post‐treatment.

Although the tundra heath is no longer N saturated, N treatment effects persist and are strongly P‐dependent. Vegetation was more resilient to N where no P was added, although shrub cover is still reduced in low‐N plots. Where P was also added (5 kg P ha−1 yr−1), there are still effects of low N on community composition and nutrient dynamics. High N, with and without P, has many lasting impacts. Importantly, N + P has caused dramatically increased moss abundance, which influences nutrient dynamics.

Our key finding is that Arctic ecosystems are slow to recover from even small N inputs, particularly where P is not limiting.
Can we safely recommend gestational weight gain below the 2009 guidelines in obese women? A systematic review and meta‐analysis
Authors: Kapadia M. Z. , Park C. K. , Beyene J. , Giglia L. , Maxwell C. , McDonald S. D. 
Published: January 2015

SummaryA systematic review was conducted to determine the risk of adverse pregnancy outcomes with gestational weight gain (GWG) below the 2009 Institute of Medicine guidelines compared with within the guidelines in obese women. MEDLINE, Embase, Cochrane Register, CINHAL and Web of Science were searched from 1 January 2009 to 31 July 2014. Quality was assessed using a modified Newcastle–Ottawa scale. Three primary outcomes were included: preterm birth, small for gestational age (SGA) and large for gestational age (LGA). Eighteen cohort studies were included. GWG below the guidelines had higher odds of preterm birth (adjusted odds ratio [AOR] 1.46; 95% confidence interval [CI] 1.07–2.00) and SGA (AOR 1.24; 95% CI 1.13–1.36) and lower odds of LGA (AOR 0.77; 95% CI 0.73–0.81) than GWG within the guidelines. Across the three obesity classes, the odds of SGA and LGA did not show any notable gradient and remained unexplored for preterm birth. Decreased odds were noted for macrosomia (AOR 0.64; 95% CI 0.54–0.77), gestational hypertension (AOR, 0.70; 95% CI 0.53–0.93), pre‐eclampsia (AOR 0.90; 95% CI 0.82–0.99) and caesarean (AOR 0.87; 95% CI 0.82–0.92). GWG below the guidelines cannot be routinely recommended but might occasionally be individualized for certain women, with caution, taking into account other known risk factors.
Environmental conditions terminate reproductive diapause and influence pheromone perception in the long‐lived moth Caloptilia fraxinella
Authors: Lemmen Joelle , Evenden Maya 
Published: January 2015

AbstractReproductive diapause enables long‐lived insects to time mating with environmental conditions suitable for offspring development. Plasticity in the perception of pheromones used in sexual communication may enable mate‐finding at the appropriate time of year. The moth Caloptilia fraxinella (Ely) (Lepidoptera: Gracillariidae) undergoes a 9‐month reproductive diapause, during which the male response to pheromone is plastic and is highest during the period of reproductive activity. The mechanisms controlling this pheromone response plasticity are not well‐understood, and the aim of the present study is to determine the main factors involved. In the present study, the impact of temperature, photoperiod, juvenile hormone analogue (JHA) and adult nutrition on diapause termination are tested using electroantennogram (EAG) and behavioural response to pheromone in male C. fraxinella. Eclosion in a state of reproductive diapause occurs in most males; diapause is maintained under short‐day or cool conditions indoors, or under natural conditions outdoors. Exposure to long‐day, warm conditions over a period of 4 weeks causes a small number of males to become behaviourally responsive to pheromone; a larger number of males become behaviourally responsive over a period of 3 months of post‐eclosion. Treatment with a JHA impacts male EAG and the behavioural response to pheromone during the period of reproductive diapause. A carbohydrate food source is not required by reproductively active adult male C. fraxinella to respond to pheromone and express mate location behaviours. The main factors involved in controlling male pheromone response plasticity and the implications of these factors for the C. fraxinella population in its expanded range are discussed.
Female access and diet affect insemination success, senescence and the cost of reproduction in the male Mexican fruit fly Anastrepha ludens
Authors: Harwood James F. , Chen Kehui , Liedo Pablo , Müller Hans‐Georg , Wang Jane‐Ling , Morice Amy E. , Carey James R. 
Published: January 2015

AbstractHypotheses exploring the influence of dietary conditions on the life‐history trade‐off between survival and reproductive success are extensively tested in female insects but only rarely explored in males. The present study examines the impact of dietary quality and female access on age‐specific reproduction and survival of the male Mexican fruit fly Anastrepha ludens Loew (Diptera: Tephritidae). There is a clear cost of female access for males with access to dietary protein, measurable as a decrease in life expectancy, which is further influenced by the age when females are introduced. A protein deficient diet reduces the lifespan benefit of virginity and masks the detrimental effect of female access on male life expectancy. Dietary protein is not necessary for reproductive success, although access to protein at eclosion improves the lifetime reproductive success of males compared to when it is delayed. Overall, reproductive success diminishes as the male flies age, regardless of the dietary conditions, providing evidence for reproductive senescence in males. Delaying the males' access to a protein source fails to influence the negative effect of age on reproductive ability. Because age‐specific reproductive rates decline with age, regardless of diet, male fitness does not benefit from lifespan extension. Therefore, males can be expected to allocate available resources towards reproductive effort in favour of an extended lifespan, regardless of mate and protein availability.
Annual dormancy cycles in buried seeds of shrub species: germination ecology of Sideritis serrata (Labiatae)
Authors: Copete M. A. , Herranz J. M. , Ferrandis P. , Copete E. 
Published: January 2015

AbstractThe germination ecology of Sideritis serrata was investigated in order to improve ex‐situ propagation techniques and management of their habitat. Specifically, we analysed: (i) influence of temperature, light conditions and seed age on germination patterns; (ii) phenology of germination; (iii) germinative response of buried seeds to seasonal temperature changes; (iv) temperature requirements for induction and breaking of secondary dormancy; (v) ability to form persistent soil seed banks; and (vi) seed bank dynamics. Freshly matured seeds showed conditional physiological dormancy, germinating at low and cool temperatures but not at high ones (28/14 and 32/18 °C). Germination ability increased with time of dry storage, suggesting the existence of non‐deep physiological dormancy. Under unheated shade‐house conditions, germination was concentrated in the first autumn. S. serrata seeds buried and exposed to natural seasonal temperature variations in the shade‐house, exhibited an annual conditional dormancy/non‐dormancy cycle, coming out of conditional dormancy in summer and re‐entering it in winter. Non‐dormant seeds were clearly induced into dormancy when stratified at 5 or 15/4 °C for 8 weeks. Dormant seeds, stratified at 28/14 or 32/18 °C for 16 weeks, became non‐dormant if they were subsequently incubated over a temperature range from 15/4 to 32/18 °C. S. serrata is able to form small persistent soil seed banks. The maximum seed life span in the soil was 4 years, decreasing with burial depth. This is the second report of an annual conditional dormancy/non‐dormancy cycle in seeds of shrub species.
Knowledge Asymmetries Between Research and Practice: A Social Systems Approach to Implementation Barriers in Organic Arable Farming
Authors: Noe Egon , Alrøe Hugo F. , Thorsøe Martin H. , Olesen Jørgen Eivind , Sørensen Peter , Melander Bo , Fog Erik 
Published: January 2015

AbstractThis article discusses the problem of implementing scientific knowledge in practice. The discussion is based on a case study of barriers to implementing research‐based principles of sustainable organic arable farming. The current literature tends to see this problem either as a dissemination issue (the linear approach) or as a failure of science to address real‐world problems (the co‐constructive approach). We argue that Luhmann's theory of social systems offers a way to understand the shortcomings of existing approaches and enables us to identify knowledge gaps that have often been overlooked so far. This theoretical claim is substantiated by an empirical analysis based on 10 in‐depth interviews with owners of organic arable farms. The farmers were interviewed about barriers to the implementation of research‐based knowledge in practice. The analysis points to the operational closure and the observational blindness of both research systems and farming systems as the keys to understanding knowledge gaps and suggests new ways of dealing with the problems of implementing research knowledge in practice.
Die‐Hard Fans and the Ivory Tower's Ties that Bind
Authors: Clotfelter Charles T. 
Published: January 2015

ObjectiveThis study examines extremely loyal fans of prominent American college sports teams. It seeks to find out how common they are and what their characteristics are.MethodsThe study defines die‐hard fans as those whose published obituaries both note this loyalty and mention the team name for a specific university. A sample of such fans associated with 26 universities is compared to individuals picked at random from obituaries from the same states. Other comparisons employ data on political‐party registration.ResultsSuch fans are uncommon, making up only about 2 percent of adults whose obituaries are published. They tend to have been predominantly male and, compared to otherwise similar adults, had higher rates of college attendance, were more likely to be white, more likely to affiliate with mainline Protestant denominations but also more likely to have no religious affiliation, volunteered more often as coaches, and had a registered affiliation to some political party.ConclusionAs a group, they represent an important link between the “common man” and the bastions of intellectual activity that are America's research universities. As illustration, many more die‐hard fans were linked to their universities by way of state residence than by attendance. And many of them had blue‐collar occupations or never went to college.
Minority Representation and Political Efficacy in Public Meetings
Authors: Williamson Anne R. , Scicchitano Michael J. 
Published: January 2015

ObjectiveThe objective of this article is to address a chief criticism of public meetings in democratic society, a lack of minority representation. Further, it explores the issue of political efficacy and the extent to which it may differ between minority and nonminority citizens.MethodsThese issues are analyzed through logistic and multiple regression models applied to the results of a random‐sample telephone survey administered across the United States (N = 601).ResultsResults indicate that members of one minority group, African Americans, are more likely to attend public meetings than whites. Further, no statistically significant differences between whites and Hispanics or other‐race individuals were found. African Americans also reported higher levels of political efficacy than whites, while no statistically significant difference was found between whites and Hispanics or other‐race individuals for this measure.ConclusionThus, public meetings are not necessarily fraught with a lack of minority representation, nor do minorities necessarily suffer from lower levels of political efficacy than whites. Findings indicate a potential for minority representation in public meetings. Thus, rather than dismissing public meetings as legally required rituals, there is reason to improve the methods used to mobilize attendance and facilitate two‐way communication between citizens and government.
Carbon stocks and carbon fluxes from a 10‐year prescribed burning chronosequence on a UK blanket peat
Authors: Clay G. D. , Worrall F. , Aebischer N. J. 
Published: January 2015

AbstractPrescribed burning is a common land management technique in many areas of the UK uplands. However, concern has been expressed at the impact of this management practice on carbon stocks and fluxes found in the carbon‐rich peat soils that underlie many of these areas. This study measured both carbon stocks and carbon fluxes from a chronosequence of prescribed burn sites in northern England. A range of carbon parameters were measured including above ground biomass and carbon stocks; net ecosystem exchange (NEE), net ecosystem respiration (Reco) and photosynthesis (Pg) from closed chamber methods; and particulate organic carbon (POC). Analysis of the CO2 data showed that burning was a significant factor in measured CO2 readings but that other factors such as month of sampling explained a greater proportion of the variation in the data. Carbon budget results showed that whereas all the plots were net sources of carbon, the most recent burn scars were smaller sources of carbon compared with the older burn scars, suggesting that burning of Calluna‐dominated landscapes leads to an ‘avoided loss’ of carbon. However, this management intervention did not lead to a transition to a carbon sink and that for carbon purposes, active peat‐forming conditions are desirable.
Integration of transcriptomics and metabolomics data specifies the metabolic response of Chlamydomonas to rapamycin treatment
Authors: Kleessen Sabrina , Irgang Susann , Klie Sebastian , Giavalisco Patrick , Nikoloski Zoran 
Published: January 2015

SummaryFlux phenotypes predicted by constraint‐based methods can be refined by the inclusion of heterogeneous data. While recent advances facilitate the integration of transcriptomics and proteomics data, purely stoichiometry‐based approaches for the prediction of flux phenotypes by considering metabolomics data are lacking. Here we propose a constraint‐based method, termed TREM‐Flux, for integrating time‐resolved metabolomics and transcriptomics data. We demonstrate the applicability of TREM‐Flux in the dissection of the metabolic response of Chlamydomonas reinhardtii to rapamycin treatment by integrating the expression levels of 982 genes and the content of 45 metabolites obtained from two growth conditions. The findings pinpoint cysteine and methionine metabolism to be most affected by the rapamycin treatment. Our study shows that the integration of time‐resolved unlabeled metabolomics data in addition to transcriptomics data can specify the metabolic pathways involved in the system's response to a studied treatment.
Objective Versus Self-Reported Physical Activity in Overweight and Obese Young Adults
Authors: Jakicic John M. , King Wendy C. , Gibbs Bethany Barone , Rogers Renee J. , Rickman Amy D. , Davis Kelliann K. , Wahed Abdus , Belle Steven H. 
Published: January 2015

Background:To compare moderate-to-vigorous intensity physical activity (MVPA) assessed via questionnaires to an objective measure of MVPA in overweight or obese young adults.Methods:MVPA was assessed in 448 [median BMI = 31.2 (Interquartile Range: 28.5–34.3) kg/m2] young adults [median age: 30.9 (Interquartile Range: 27.8–33.7) years]. Measures included the SenseWear Armband (MVPAOBJ), the Paffenbarger Questionnaire (MVPAPAFF), and the Global Physical Activity Questionnaire (GPAQ). The GPAQ was used to compute total MVPA (MVPAGPAQ-TOTAL) and MVPA from transportation and recreation (MVPAGPAQ-REC).Results:The association between MVPAOBJ and MVPAPAFF was rs = 0.40 (P < .0001). Associations between MVPAOBJ and MVPAGPAQ-TOTAL and MVPAGPAQ-REC were rs = 0.19 and rs = 0.32, respectively (P < .0001). MVPAGPAQ-TOTAL was significantly greater than MVPAOBJ (P < .0001). Median differences in MET-min/week between MVPAOBJ and MVPAPAFF or MVPAGPAQ-REC were not significantly different from zero. There was proportional bias between each self-reported measure of MVPA and MVPAOBJ. There were significant associations between all measures of MVPA and fitness. MVPAOBJ was significantly associated with BMI and percent body fat.Conclusions:Objective and self-reported measures of MVPA are weakly to moderately correlated, with substantial differences between measures. MVPAOBJ provided predictive validity with fitness, BMI, and percent body fat. Thus, an objective measure of MVPA may be preferred to self-report in young adults.
Playing Together: The Physical Activity Beliefs and Behaviors of Urban Aboriginal Youth
Authors: Kerpan Serene , Humbert Louise 
Published: January 2015

Background:Urban Aboriginal youth are a rapidly growing segment of the Canadian population that unfortunately bears a disproportionate level of illness. One way to improve the health of urban Aboriginal youth is to increase their physical activity. It is important to understand what this group’s beliefs and behaviors are on physical activity so that programs that meet their needs can be developed.Methods:This ethnographic study engaged 15 urban Aboriginal youth to understand what their physical activity beliefs and behaviors were.Results:Results revealed 4 themes: “group physical activity preference,” “focus on the family,” “traditional physical activity,” and “location of residence as a barrier.” These themes illustrated that urban Aboriginal youth have a preference for group physical activity and enjoy traditional Aboriginal forms of activity. Results also showed that the family plays a critical role in their physical activity patterns. Lastly, participants in this study believed that their location of residence was a barrier to physical activity.Conclusion:Community leaders need to be sensitive to the barriers that this cultural group faces and build on the strengths that are present among this group when developing physical activity programming.
A Comparison between Simulated and Observed Surface Energy Balance at the Svalbard Archipelago
Authors: Aas Kjetil Schanke , Berntsen Terje Koren , Boike Julia , Etzelmüller Bernd , Kristjánsson Jón Egill , Maturilli Marion , Schuler Thomas Vikhamar , Stordal Frode , Westermann Sebastian 
Published: January 2015

AbstractThe surface energy balance at the Svalbard Archipelago has been simulated at high resolution with the Weather Research and Forecasting Model and compared with measurements of the individual energy fluxes from a tundra site near Ny-Ålesund (located north of Norway), as well as other near-surface measurements across the region. For surface air temperature, a good agreement between model and observations was found at all locations. High correlations were also found for daily averaged surface energy fluxes within the different seasons at the main site. The four radiation components showed correlations above 0.5 in all seasons (mostly above 0.9), whereas correlations between 0.3 and 0.8 were found for the sensible and latent heat fluxes. Underestimation of cloud cover and cloud optical thickness led to seasonal biases in incoming shortwave and longwave radiation of up to 30%. During summer, this was mainly a result of distinct days on which the model erroneously simulated cloud-free conditions, whereas the incoming radiation biases appeared to be more related to underestimation of cloud optical thickness during winter. The model overestimated both sensible and latent heat fluxes in most seasons. The model also initially overestimated the average Bowen ratio during summer by a factor of 6, but this bias was greatly reduced with two physically based model modifications that are related to frozen-ground hydrology. The seasonally averaged ground/snow heat flux was mostly in agreement with observations but showed too little short-time variability in the presence of thick snow. Overall, the model reproduced average temperatures well but overestimated diurnal cycles and showed considerable biases in the individual energy fluxes on seasonal and shorter time scales.
Effects of Localized Grid Refinement on the General Circulation and Climatology in the Community Atmosphere Model
Authors: Zarzycki Colin M. , Jablonowski Christiane , Thatcher Diana R. , Taylor Mark A. 
Published: January 2015

Abstract
Using the spectral element (SE) dynamical core within the National Center for Atmospheric Research–Department of Energy Community Atmosphere Model (CAM), a regionally refined nest at 0.25° (~28 km) horizontal resolution located over the North Atlantic is embedded within a global 1° (~111 km) grid. A 23-yr simulation using Atmospheric Model Intercomparison Project (AMIP) protocols and default CAM, version 5, physics is compared to an identically forced run using the global 1° (~111 km) grid without refinement. The addition of a refined patch over the Atlantic basin does not noticeably affect the global circulation. In the area where the refinement is located, large-scale precipitation increases with the higher resolution. This increase is partly offset by a decrease in precipitation resulting from convective parameterizations, although total precipitation is also slightly higher at finer resolutions. Equatorial waves are not significantly impacted when traversing multiple grid spacings. Despite the grid transition region bisecting northern Africa, local zonal jets and African easterly wave activity are highly similar in both simulations. The frequency of extreme precipitation events increases with resolution, although this increase is restricted to the refined patch. Topography is better resolved in the nest as a result of finer grid spacing. The spatial patterns of variables with strong orographic forcing (such as precipitation, cloud, and precipitable water) are improved with local refinement. Additionally, dynamical features, such as wind patterns, associated with steep terrain are improved in the variable-resolution simulation when compared to the uniform coarser run.