bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unravelling the natural dynamics and resilience patterns of underwater Mediterranean forests: insights from the demography of the brown alga Cystoseira zosteroides
Authors: Capdevila Pol , Hereu Bernat , Riera Juan Lluís , Linares Cristina 
Published: June 2016

Summary

Despite being among the most important habitat‐forming organisms in temperate seas almost nothing is known about the demography of many algal species. This limits our ability to understand the effects of global and local stressors and to predict future trends under ongoing environmental change, which in turn hinders conservation actions.

Cystoseira species develop important forest‐like assemblages along the sublittoral zone in the Mediterranean Sea. In this study we investigated the natural population dynamics and resilience patterns of a deep‐water brown and canopy‐forming macroalga, Cystoseira zosteroides. We used density‐dependent and stochastic matrix models to estimate its basic life‐history and compare it with other relevant habitat‐forming marine (brown algae) and terrestrial (plants) species. We also evaluated the consequences of increasing the disturbances caused by storms and the impact of lost fishing gear, and their interaction, on C. zosteroides population dynamics.

The population dynamics of C. zosteroides showed similar patterns to terrestrial long‐lived species such as shrubs and trees, with high survival due to their investment in structural biomass. Our data and models suggest that this species is able to buffer mortality pulses by increasing the number of recruits (and probably recruit survival) due to the new space liberated and, therefore, lower intraspecific competition. Nevertheless, when storm disturbances were more frequent than once every 50 years, their populations collapsed, and this effect worsened when several stressors acted simultaneously.

Our results improve our understanding about the demography of algal forests, and highlight the fact that increases in local and global stressors may erode the resilience of macroalgae, resulting in a loss of structural complexity in the benthic communities of temperate seas.

Synthesis. Our findings reveal that deep‐water C. zosteroides forests display slow population dynamics, similar to terrestrial perennials and trees. The increase in disturbance frequencies due to global and local stressors and their interaction will cause the decline of underwater macroalgal forests and may induce profound changes in their population and community dynamics.
Evidence of local adaptation to fine‐ and coarse‐grained environmental variability inPoa alpinain the Swiss Alps
Authors: Hamann Elena , Kesselring Halil , Armbruster Georg F. J. , Scheepens J. F. , Stöcklin Jürg 
Published: June 2016

SummaryIn the alpine landscape, characterized by high spatiotemporal heterogeneity and barriers, divergent selection is likely to lead to local adaptation of plant populations either through adaptive genetic differentiation or through phenotypic plasticity. The relative importance of these processes has rarely been investigated in relation to the spatial scale of environmental heterogeneity. In this study, we used reciprocal transplantation experiments of populations across nearby and distant field sites to shed light on these complementary processes.We reciprocally transplanted populations of the widespread alpine grass,Poa alpina, within and across regions in the Swiss Alps. We inferred local adaptation at the metapopulation level by comparing fitness of plants transplanted to their site of origin and to nearby or distant novel sites. Additionally, we measured specific leaf area (SLA) and performed selection analyses to investigate directional selection on mean trait value at each field site and on the degree of plasticity of this trait to assess whether plastic responses were adaptive. In parallel, all populations were genotyped with microsatellite markers to assess neutral molecular differentiation.Molecular differentiation was high among populations within and among regions, indicating restricted gene flow amongP. alpinapopulations. Reproductive biomass was highest in individuals grown in their region of origin, revealing local adaptation to coarse‐grained environmental variability. Similarly, inflorescence height, associated with reproductive biomass, reflected adaptation to fine‐ and coarse‐grained environmental variability. Furthermore, we found evidence that plasticity inSLAacross coarse‐grained habitats was correlated with plant fitness, suggesting that plasticity in this trait is adaptive.Synthesis. Our results revealed adaptive genetic differentiation betweenP. alpinapopulations in the Swiss Alps reflecting local adaptation. Furthermore, high phenotypic plasticity inSLAcontributed to the maintenance of fitness homoeostasis across habitats. Hence, adaptive genetic differentiation and phenotypic plasticity play a complementary role for adaption ofP. alpinato environmental heterogeneity in the Swiss Alps and both may be critical to mitigate local extinction risk under rapid climate change.
Regeneration processes on coarse woody debris in mixed forests: do tree germinants and seedlings have species‐specific responses when grown on coarse woody debris?
Authors: Orman Olga , Adamus Michał , Szewczyk Janusz 
Published: June 2016

Summary

Tree regeneration on coarse woody debris (CWD) is considered to be one the most ecologically valuable aspects of CWD in forest systems. However, most studies have focused solely on uncovering the differences in establishment and growth on CWD (regarded as a homogeneous substrate) in comparison with the forest floor. Our study concentrates on the underlying mechanisms of germinant and seedling colonization patterns and demographic responses relative to various properties of CWD.

We analysed the effects of CWD properties (decay class, form, species and diameter) on: (i) germinant and seedling annual counts; (ii) annual germinant and seedling survival; and (iii) seedling growth and height. Our study comprised three species (beech, fir and spruce) over 7‐year span in two old‐growth stands in the Western Carpathians, and employed generalized linear models and mixed models to test for differences between species.

CWD properties affected regeneration at the germination stage. There were some demographic differences between species relative to CWD properties. Decay class had the most pronounced effect on beech, not only on its establishment but also survival and growth. Beech and spruce established and survived in higher densities on beech CWD, while their height growth was enhanced on conifer‐derived CWD, particularly on spruce CWD. Stumps enhanced establishment of all species and survival of conifer seedlings.

Synthesis. Our study shows that CWD properties do influence seedling establishment, growth, height distribution and survival. Moreover, there may be trade‐offs between seedling growth and survival among tree species growing on different species of CWD. This highlights the need to include CWD heterogeneity as a factor that can affect the role of CWD in regeneration in forest ecosystems.
Mechanisms of resilience: empirically quantified positive feedbacks produce alternate stable states dynamics in a model of a tropical reef
Authors: Muthukrishnan Ranjan , Lloyd‐Smith James O. , Fong Peggy 
Published: June 2016

Summary

Alternate stable states (ASS) theory is a dominant conceptual framework for understanding processes that support resilience of ecological communities in the face of multiple anthropogenic disturbances. For decades, coral reefs have been cited as a classic example of ASS, yet this position remains highly controversial, largely because convincing empirical evaluations have been elusive.

Using a combination of empirical measurements of positive feedback processes and simulation modelling, we assessed ASS in coral reefs of the Eastern Tropical Pacific (ETP) by identifying the potential for multiple basins of attraction from a mechanistic perspective.

Using bioassays of algal growth and consumption, we quantified two spatially localized positive feedback mechanisms on coral reefs: increasing herbivore activity associated with higher coral abundances and amelioration of nutrient limitation leading to higher algal growth in areas with higher algal abundance.

Analysis of a model of benthic community dynamics incorporating these feedbacks showed they were central to producing hysteresis and bistability in the model, two hallmarks of ASS. Further, reefs simulated with conditions matching those measured at Isla Contadora, Panamá, displayed ASS dynamics while producing spatial patterns matching field observations. This provides model‐derived support, based on empirically measured conditions of ETP reefs, for the presence of ASS.

Synthesis. The combination of experimental bioassays to measure feedback strengths and simulation models to evaluate the influence of those feedbacks provides a novel, non‐destructive approach to evaluating ASS dynamics that can be applied in threatened ecosystems where classic approaches are not viable.
The role of habitat filtering in the leaf economics spectrum and plant susceptibility to pathogen infection
Authors: Welsh Miranda E. , Cronin James Patrick , Mitchell Charles E. 
Published: June 2016

SummaryThe leaf economics spectrum (LES) describes global covariation in the traits of plant leaves. TheLESis thought to arise from biophysical constraints and habitat filtering (ecological selection against unfit trait combinations along environmental gradients). However, the role of habitat filtering in generating theLEShas not been tested experimentally.If the process of habitat filtering plays a role in generating theLES, theLEScould weaken in communities that have yet to be filtered by the current environment, for example after abiotic environmental change.LEStraits are commonly used to predict community and ecosystem processes, and if theLESweakens in unfiltered communities,LES‐based models may no longer apply.In the glasshouse, we experimentally simulated three stages of habitat filtering in response to abiotic change: from unfiltered, to semi‐filtered, to completely filtered communities. In each stage, we quantified the strength of theLESand assessed the accuracy of trait‐based models of an important ecological process, pathogen infection.The strength of theLESincreased with the completeness of habitat filtering, as did the accuracy of trait‐based models of plant susceptibility to pathogen infection.Synthesis. Our results suggest that habitat filtering plays a fundamental role in strengthening the trait correlations of theLESand that trait‐based models may be less accurate when communities have not been filtered by the current environment, for example, following rapid environmental change.
Microbial Diversity of Type I Sourdoughs Prepared and Back‐Slopped with Wholemeal and Refined Soft (Triticum aestivum) Wheat Flours
Authors: Taccari Manuela , Aquilanti Lucia , Polverigiani Serena , Osimani Andrea , Garofalo Cristiana , Milanović Vesna , Clementi Francesca 
Published: June 2016

AbstractThe fermentation of type I sourdough was studied for 20 d with daily back‐slopping under laboratory and artisan bakery conditions using 1 wholemeal and 2 refined soft wheat (Triticum aestivum) flours. The sourdough bacterial and yeast diversity and dynamics were investigated by plate counting and a combination of culture‐dependent and culture‐independent PCR‐DGGE approach. The pH, total titrable acidity, and concentration of key organic acids (phytic, lactic, and acetic) were measured. Three flours differed for both chemical and rheological properties. A microbial succession was observed, with the atypical sourdough species detected at day 0 (i.e. Lactococcus lactis and Leuconostoc holzapfelii/citreum group for bacteria and Candida silvae and Wickerhamomyces anomalus for yeasts) being progressively replaced by taxa more adapted to the sourdough ecosystem (Lactobacillus brevis, Lactobacillus alimentarius/paralimentarius, Saccharomyces cerevisiae). In mature sourdoughs, a notably different species composition was observed. As sourdoughs propagated with the same flour at laboratory and artisan bakery level were compared, the influence of both the substrate and the propagation environment on microbial diversity was assumed.
Measuring the biodiversity of microbial communities by flow cytometry
Authors: Props Ruben , Monsieurs Pieter , Mysara Mohamed , Clement Lieven , Boon Nico 
Published: June 2016

Summary

Measuring the microbial diversity in natural and engineered environments is important for ecosystem characterization, ecosystem monitoring and hypothesis testing. Although the conventional assessment through single marker gene surveys has resulted in major advances, the complete procedure remains slow (i.e. weeks to months), labour‐intensive and susceptible to multiple sources of laboratory and data processing bias. Growing interest, in highly resolved, temporal surveys of microbial diversity, necessitates rapid, inexpensive and robust analytical platforms that require limited computational effort.

Here, we demonstrate that sensitive single‐cell measurements of phenotypic attributes, obtained via flow cytometry, can provide fast (i.e. within minutes) first‐line assessments of microbial diversity dynamics, without demanding extensive sample preparation and downstream data processing. We developed a data processing pipeline that fits bivariate kernel density functions to phenotypic parameter combinations of an entire microbial community and concatenates them to a single one‐dimensional phenotypic fingerprint. By calculating established diversity metrics from such phenotypic fingerprints, we construct an alternative interpretation of the microbial diversity that incorporates distinct phenotypic traits underlying cell‐to‐cell heterogeneity (i.e. morphology and nucleic acid content).

Based on a detailed longitudinal study of a highly dynamic microbial ecosystem, our approach delivered temporal alpha diversity profiles that strongly correlated with the reference diversity, as estimated by 16S rRNA amplicon sequencing. This strongly suggests that the distribution of a limited amount of phenotypic features within a microbial community already provides sufficient resolving power for the measurement of diversity dynamics at the species level.

We present a fast, robust analysis method for monitoring the microbial biodiversity of natural and engineered ecosystems that correlates well with the conventional marker gene surveys. Our work has both applied and fundamental implications that stretch from ecosystem monitoring and studies on microbial community dynamics, to supervised sampling strategies. Furthermore, our approach offers perspectives for the development of online and in situ monitoring systems for microbial ecosystems.
CDMetaPOP: an individual‐based, eco‐evolutionary model for spatially explicit simulation of landscape demogenetics
Authors: Landguth Erin L. , Bearlin Andrew , Day Casey C. , Dunham Jason 
Published: June 2016

Summary

Combining landscape demographic and genetics models offers powerful methods for addressing questions for eco‐evolutionary applications.

Using two illustrative examples, we present Cost–Distance Meta‐POPulation, a program to simulate changes in neutral and/or selection‐driven genotypes through time as a function of individual‐based movement, complex spatial population dynamics, and multiple and changing landscape drivers.

Cost–Distance Meta‐POPulation provides a novel tool for questions in landscape genetics by incorporating population viability analysis, while linking directly to conservation applications.
A minimum‐impact, flexible tool to study vocal communication of small animals with precise individual‐level resolution
Authors: Gill Lisa F. , D'Amelio Pietro B. , Adreani Nicolas M. , Sagunsky Hannes , Gahr Manfred C. , ter Maat Andries 
Published: June 2016

Summary

To understand both proximate and ultimate factors shaping vocal communication, it is fundamental to obtain reliable information of participating individuals on different levels: First, it is necessary to separate and assign the individuals' vocalisations. Secondly, the precise timing of vocal events needs to be retained. Thirdly, vocal behaviour should be recorded from undisturbed animals in meaningful settings. A growing number of studies used animal‐attached microphones to tackle these issues, but the implications for the study species and the research question often receded into the background. Here, we aim to initiate a discussion about the limitations, possible applications and the broader potential of such methods.

Using lightweight wireless microphone backpacks (0·75 g including customised leg‐loop harness) combined with multi‐channel recording equipment, we captured vocal behaviour of small songbirds. We evaluated the effect of the devices at various levels, including an assessment of how vocal and locomotor activities were affected by initial device attachment and battery exchange. We compared our approach to existing studies and identified suitable research examples.

We acquired continuous vocalisation recordings of zebra finches, and unequivocally assigned them to interacting individuals, with system‐based synchrony, irrespective of background noise. We found effects of initial backpack attachment and of battery replacement on vocal and locomotor activity, but they were minimised through the extended recording duration (ca. 16 days) that outlasted habituation effects (ca. 3 days).

This method provides the tools to integrate individual vocal communications into a group setting, while enabling animals to behave freely in undisturbed, structured and acoustically complex environments. By minimising the effects on the animals, the behaviour under study, and ultimately on the research question, this approach will revolutionise the ability to capture individual‐level vocalisations in a variety of communication contexts, opening up many new opportunities to address novel research questions.
Developmental course of non‐medical use of prescription drugs from adolescence to adulthood in the United States: national longitudinal data
Authors: McCabe Sean Esteban , Kloska Deborah D. , Veliz Philip , Jager Justin , Schulenberg John E. 
Published: June 2016

AbstractAimsTo identify the developmental course of non‐medical use of four separate prescription drug classes (opioids, sedatives, stimulants and tranquilizers) by examining the general functional growth and related covariates during the transition from adolescence to adulthood in the United States.DesignNationally representative probability samples of high school seniors were followed longitudinally across five waves (waves 1, 2, 3, 4 and 5: modal ages 18, 19/20, 21/22, 23/24 and 25/26 years, respectively).SettingData were collected via self‐administered questionnaires to high school seniors and young adults in the United States.ParticipantsThe sample consisted of nearly 72 000 individuals in 30 cohorts (high school senior years of 1977–2006) who participated in at least one wave.MeasurementsSelf‐reports of annual non‐medical use of prescription opioids, sedatives, stimulants, and tranquilizers.FindingsThe annual non‐medical use of prescription opioids, sedatives, stimulants and tranquilizers was highest at wave 1 over the five waves. There was a consistent descending path (linear and quadratic slopes, P < 0.001) in annual non‐medical use from baseline across all four prescription drug classes (e.g. opioids linear slope = −0.043 and opioids quadratic slope = 0.034, P < 0.001). While the annual non‐medical use of stimulants declined over time (linear slope = 0.063, P < 0.01; quadratic slope = −0.133, P < 0.001), the same decrease was not observed for the annual non‐medical use of prescription opioids, sedatives or tranquilizers when controlling for socio‐demographic and substance use behaviors at baseline. The covariates associated with the general functional growth differed across the four prescription drug classes.ConclusionsThe non‐medical use of prescription opioids, sedatives, stimulants and tranquilizers appears to peak during late adolescence, suggesting preventive intervention efforts should be initiated in early adolescence. The developmental course of non‐medical use is not the same among all four classes of prescription drugs, suggesting that each drug class warrants individual research.
Behavioural tasks sensitive to acute abstinence and predictive of smoking cessation success: a systematic review and meta‐analysis
Authors: Grabski Meryem , Curran H. Valerie , Nutt David J. , Husbands Stephen M. , Freeman Tom P. , Fluharty Meg , Munafò Marcus R. 
Published: June 2016

AbstractBackground and aimsPerformance on cognitive tasks may be sensitive to acute smoking abstinence and may also predict whether quit attempts fail. Our aim was to conduct a systematic review and meta‐analysis to identify cognitive tasks sensitive to acute abstinence and predictive of smoking cessation success.MethodsEmbase, Medline, PsycInfo and Web of Science were searched up to March 2016. Studies were included if they enrolled adults and assessed smoking using a quantitative measure. Studies were combined in a random effects meta‐analysis.ResultsWe included 42 acute abstinence studies and 13 cessation studies. There was evidence for an effect of abstinence on delay discounting [d = 0.26, 95% confidence interval (CI) = 0.07–0.45,P = 0.005], response inhibition (d = 0.48, 95% CI = 0.26–0.70,P < 0.001), mental arithmetic (d = 0.38, 95% CI = 0.06–0.70,P = 0.018), and recognition memory (d = 0.46, 95% CI = 0.23–0.70,P < 0.001). In contrast, performance on the Stroop (d = 0 .17, 95% CI = −0.17–0.51,P = 0.333) and smoking Stroop (d = 0.03, 95% CI = −0.11–0.17,P = 0.675) task was not influenced by abstinence. We found only weak evidence for an effect of acute abstinence on dot probe task performance (d = 0.15, 95% CI = −0.01–0.32,P = 0.072). The design of the cessation studies was too heterogeneous to permit meta‐analysis.ConclusionsCompared with satiated smokers, acutely abstinent smokers display higher delay discounting, lower response inhibition, impaired arithmetic and recognition memory performance. However, reaction‐time measures of cognitive bias appear to be unaffected by acute tobacco abstinence. Conclusions about cognitive tasks that predict smoking cessation success were limited by methodological inconsistencies.
Mechanisms of Action and Toxicity of the Mycotoxin Alternariol: A Review
Authors: Solhaug Anita , Eriksen Gunnar S. , Holme Jørn A. 
Published: June 2016

AbstractThe mycotoxin alternariol (AOH) is produced by Alternaria fungi. It occurs naturally in foodstuffs and is frequently found as contaminant in fruit and grain products. Most information regarding AOH toxicity and the potential mechanisms involved comes from in vitro studies, as only very limited in vivo studies have been performed. AOH forms reactive oxygen species (ROS) and interacts with DNA topoisomerase, thereby generating both single (SSB)‐ and double‐strand DNA beaks (DSB). This triggers various DNA damage response pathways. AOH causes a marked reduction in proliferation in mammalian cells due to cell cycle arrest often in the G2/M‐phase. After an additional inhibition of cytokinesis, cells with abnormal nuclei as well as polyploidy are reported. In macrophages, AOH may increase autophagic activity and induce senescence. Furthermore, AOH is found to change the morphology and phenotype of various human macrophage cell models. Studies so far indicate that the AOH‐induced effects are primarily a result of DSB via its effects on topoisomerase activity. Thus, most probably there will be a threshold for the AOH‐induced effects, typically seen in the 5–10 μM range. These in vitro mechanistic studies further support the in vivo studies suggesting low acute toxicity. However, a decreased immune response to infections and/or a disturbed balance of the adaptive immune system when exposed together with other mycotoxins cannot be excluded. This hypothesis needs to be further explored with proper in vivo studies.