bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mean annual temperature influences local fine root proliferation and arbuscular mycorrhizal colonization in a tropical wet forest
Authors: Pierre Suzanne , Litton Creighton M. , Giardina Christian P , Sparks Jed P. , Fahey Timothy J. 
Published: August 2020

AbstractMean annual temperature (MAT) is an influential climate factor affecting the bioavailability of growth‐limiting nutrients nitrogen (N) and phosphorus (P). In tropical montane wet forests, warmer MAT drives higher N bioavailability, while patterns of P availability are inconsistent across MAT. Two important nutrient acquisition strategies, fine root proliferation into bulk soil and root association with arbuscular mycorrhizal fungi, are dependent on C availability to the plant via primary production. The case study presented here tests whether variation in bulk soil N bioavailability across a tropical montane wet forest elevation gradient (5.2°C MAT range) influences (a) morphology fine root proliferation into soil patches with elevated N, P, and N+P relative to background soil and (b) arbuscular mycorrhizal fungal (AMF) colonization of fine roots in patches. We created a fully factorial fertilized root ingrowth core design (N, P, N+P, unfertilized control) representing soil patches with elevated N and P bioavailability relative to background bulk soil. Our results show that percent AMF colonization of roots increased with MAT (r2 = .19, p = .004), but did not respond to fertilization treatments. Fine root length (FRL), a proxy for root foraging, increased with MAT in N+P‐fertilized patches only (p = .02), while other fine root morphological parameters did not respond to the gradient or fertilized patches. We conclude that in N‐rich, fine root elongation into areas with elevated N and P declines while AMF abundance increases with MAT. These results indicate a tradeoff between P acquisition strategies occurring with changing N bioavailability, which may be influenced by higher C availability with warmer MAT.
Heat stress responses and population genetics of the kelp Laminaria digitata (Phaeophyceae) across latitudes reveal differentiation among North Atlantic populations
Authors: Liesner Daniel , Fouqueau Louise , Valero Myriam , Roleda Michael Y. , Pearson Gareth A. , Bischof Kai , Valentin Klaus , Bartsch Inka 
Published: August 2020

AbstractTo understand the thermal plasticity of a coastal foundation species across its latitudinal distribution, we assess physiological responses to high temperature stress in the kelp Laminaria digitata in combination with population genetic characteristics and relate heat resilience to genetic features and phylogeography. We hypothesize that populations from Arctic and cold‐temperate locations are less heat resilient than populations from warm distributional edges. Using meristems of natural L. digitata populations from six locations ranging between Kongsfjorden, Spitsbergen (79°N), and Quiberon, France (47°N), we performed a common‐garden heat stress experiment applying 15°C to 23°C over eight days. We assessed growth, photosynthetic quantum yield, carbon and nitrogen storage, and xanthophyll pigment contents as response traits. Population connectivity and genetic diversity were analyzed with microsatellite markers. Results from the heat stress experiment suggest that the upper temperature limit of L. digitata is nearly identical across its distribution range, but subtle differences in growth and stress responses were revealed for three populations from the species’ ecological range margins. Two populations at the species’ warm distribution limit showed higher temperature tolerance compared to other populations in growth at 19°C and recovery from 21°C (Quiberon, France), and photosynthetic quantum yield and xanthophyll pigment responses at 23°C (Helgoland, Germany). In L. digitata from the northernmost population (Spitsbergen, Norway), quantum yield indicated the highest heat sensitivity. Microsatellite genotyping revealed all sampled populations to be genetically distinct, with a strong hierarchical structure between southern and northern clades. Genetic diversity was lowest in the isolated population of the North Sea island of Helgoland and highest in Roscoff in the English Channel. All together, these results support the hypothesis of moderate local differentiation across L. digitata's European distribution, whereas effects are likely too weak to ameliorate the species’ capacity to withstand ocean warming and marine heatwaves at the southern range edge.
Environmental factors affect the response of microbial extracellular enzyme activity in soils when determined as a function of water availability and temperature
Authors: Gomez Enrique J. , Delgado José A. , Gonzalez Juan M. 
Published: August 2020

AbstractMicroorganisms govern soil carbon cycling with critical effects at local and global scales. The activity of microbial extracellular enzymes is generally the limiting step for soil organic matter mineralization. Nevertheless, the influence of soil characteristics and climate parameters on microbial extracellular enzyme activity (EEA) performance at different water availabilities and temperatures remains to be detailed. Different soils from the Iberian Peninsula presenting distinctive climatic scenarios were sampled for these analyses. Results showed that microbial EEA in the mesophilic temperature range presents optimal rates under wet conditions (high water availability) while activity at the thermophilic temperature range (60°C) could present maximum EEA rates under dry conditions if the soil is frequently exposed to high temperatures. Optimum water availability conditions for maximum soil microbial EEA were influenced mainly by soil texture. Soil properties and climatic parameters are major environmental components ruling soil water availability and temperature which were decisive factors regulating soil microbial EEA. This study contributes decisively to the understanding of environmental factors on the microbial EEA in soils, specifically on the decisive influence of water availability and temperature on EEA. Unlike previous belief, optimum EEA in high temperature exposed soil upper layers can occur at low water availability (i.e., dryness) and high temperatures. This study shows the potential for a significant response by soil microbial EEA under conditions of high temperature and dryness due to a progressive environmental warming which will influence organic carbon decomposition at local and global scenarios.
Two experimental designs generate contrasting patterns of behavioral differentiation along a latitudinal gradient in Lestes sponsa—Common‐garden not so common after all?
Authors: Golab Maria J. , Brodin Tomas , Sniegula Szymon 
Published: August 2020

AbstractUnderstanding why and how behavioral profiles differ across latitudes can help predict behavioral responses to environmental change. The first response to environmental change that an organism exhibits is commonly a behavioral response. Change in one behavior usually results in shifts in other correlated behaviors, which may adaptively or maladaptively vary across environments and/or time. However, one important aspect that is often neglected when studying behavioral expressions among populations is if/how the experimental design might affect the results. This is unfortunate since animals often plastically modify their behavior to the environment, for example, rearing conditions. We studied behavioral traits and trait correlations in larvae of a univoltine damselfly, Lestes sponsa, along its latitudinal distribution, spreading over 3,300 km. We compared behavioral profiles among larvae grown in two conditions: (a) native temperatures and photoperiods or (b) averaged constant temperatures and photoperiods (common‐garden). We hypothesized latitudinal differences in behavioral traits regardless of the conditions in which larvae were grown, with northern populations expressing higher activity, boldness, and foraging efficiency. When grown in native conditions, northern larvae were bolder, more active and more effective in prey capture than central and low latitude populations, respectively, as well as showed the strongest behavioral correlations. In contrast, larvae reared in common‐garden conditions showed no differences between regions in both individual traits and trait correlations. The results suggest different selective pressures acting on the studied traits across populations, with environment as a central determinant of the observed trait values. Common‐garden designed experiments may evoke population‐dependent levels of plastic response to the artificial conditions and, hence, generate results that lack ecological relevance when studying multi‐population differences in behavior.
Effects of drought and mycorrhiza on wheat and aphid infestation
Authors: Pons Caroline , Voß Ann‐Cathrin , Schweiger Rabea , Müller Caroline 
Published: August 2020

AbstractThe impacts of climate change on worldwide crop production become increasingly severe. Thus, sustainable enhancements of agricultural production are needed. The present study investigated the effects of drought and arbuscular mycorrhizal fungi on wheat plants (Triticum aestivum) and their interaction with aphids. Considering predicted climate change scenarios, wheat plants were exposed to well‐watered conditions, continuous drought (CD), or pulsed (PD) drought and plants were grown without (NM) or with mycorrhizal (AM) fungi. Ear biomass and harvest index were evaluated when grains were produced. Moreover, drought‐ and mycorrhiza‐induced changes in the amino acid composition of leaf phloem exudates were studied and the population growth and survival of Sitobion avenae aphids on those plants measured. Wheat plants responded differently toward the irrigation treatments. Under drought stress, ear biomass was reduced, while AM resulted in an enhanced harvest index. In phloem exudates especially, relative concentrations of the osmoprotectant proline were modulated by drought. Aphid population size was influenced by the interaction of drought and mycorrhiza treatment. This study emphasizes the pronounced influence of irrigation frequency on plant performance and indicates positive contributions of AM that may be relevant for agriculture.
The photoresponsive micropump tape using gas generation technology
Authors: Akagi Yoshinori , Sugita Daihei , Yamamoto Kazuki 
Published: August 2020

AbstractRecently, micro‐TAS (Micro Total Analysis Systems) that performs genetic testing on devices containing microfluidics has been actively studied. In micro‐TAS, a micromixer and a microreactor provided on a microfluidic device are driven by feeding reagents with micropumps. Various micropumps were developed and studied: for example, displacement pumps, electro‐osmotic pumps, chemically actuated micropumps. The diaphragm type, which is a general pump, has the problem that reagents stagnation flow on the microfluidic device due to pulsation. Focusing on gas generation technology based on photochemical reaction, we thought that gas generation by light irradiation could be used for micropumps. Here we reported the basic concept for the photochemical actuated micropump and characterized performance of the device.
Invasive dominance and resident diversity: unpacking the impact of plant invasion on biodiversity and ecosystem function
Authors: Livingstone Stuart W. , Isaac Marney E. , Cadotte Marc W. 
Published: August 2020

AbstractPlant invasions have consistently been shown to cause significant reductions in the diversity of recipient plant communities; an effect that can cascade through ecosystems to impact the stocks and flows of nutrients and energy as well as the diversity of higher trophic levels. However, the manner in which invasive plants alter ecosystem functioning and trophic interactions is highly variable can occur through the direct effects of the invader's abundance and its indirect effects via changes in community diversity. Understanding the nature of these interactions between plant invasion, community diversity and ecosystem functioning can provide insight for ecosystem managers. We evaluated whether plant invasion alters the relationship between biodiversity and ecosystem function (BEF) by comparing BEF models that either include or subtract the diversity and function values associated with the invasive vine,Vincetoxicum rossicum.To do this, we (1) characterizeV. rossicumwithin the functional trait space of the regional species pool, (2) assess how different components of plant biodiversity vary along aV. rossicuminvasion gradient, and (3) examine howV. rossicuminvasion affects BEF relationships and trophic interactions, both at the plot‐scale and incrementally along a site‐level invasion gradient. In general, we found thatV. rossicuminvasion was associated with significant declines in plant community diversity across a suite of biodiversity measures; a consequence ofV. rossicum's functional trait structure (height and specific leaf area). We also found thatV. rossicuminvasion resulted in significantly greater productivity (i.e., dominance effects in the inclusion model), but also that the diversity of the remaining resident community was positively associated with productivity (i.e., niche complementarity in the subtraction model). Further, we observed that while the relationship between flower cover and pollinator diversity was positive for both the inclusion and subtraction models, this relationship was stronger in the absence ofV. rossicum. Our findings suggest that while plant invasion can result in enhanced productivityviadominance effects, this comes at the cost of significant declines in diversity. However, it is also the case that remaining resident diversity can exhibit positive effects on multiple functions and support for higher trophic levels.
Changes in prey, turbidity, and competition reduce somatic growth and cause the collapse of a fish population
Authors: Korman Josh , Yard Michael D. , Dzul Maria C. , Yackulic Charles B. , Dodrill Michael J. , Deemer Bridget R. , Kennedy Theodore A. 
Published: August 2020

AbstractSomatic growth exerts strong control on patterns in the abundance of animal populations via effects on maturation, fecundity, and survival rates of juveniles and adults. In this paper, we quantify abiotic and biotic drivers of rainbow trout growth in the Colorado River, Arizona, USA, and the resulting impact on spatial and temporal variation in abundance. Inferences are based on ~10,000 observations of individual growth rates obtained through an intensive mark–recapture effort conducted over 5 yrs (2012–2016) in a 130‐km long study segment downstream of Glen Canyon Dam. Prey availability, turbidity‐driven feeding efficiency, and intraspecific competition were the dominant drivers of rainbow trout growth. Discharge, water temperature, and solar insulation were also evaluated but had a smaller influence. Mixed‐effect models explained 79–82% of the variability in observed growth rates, with fixed covariate effects explaining 79–87% of the total variation in growth parameters across five reaches and 18 quarterly sampling intervals. Reductions in growth owing in part to a phosphorous‐driven decline in prey availability, led to a substantive loss in mass and poor fish condition. This in turn lowered survival rates and delayed maturation, which led to a rapid decline in abundance and later recruitments. Reductions in feeding efficiency, due to episodic inputs of fine sediment from tributaries, and warmer water temperatures, contributed to reduced growth in downstream reaches, which led to more severe declines in abundance. Somatic growth rates increased following the population collapse due to reduced competition, and in the absence of substantive increases in prey availability. Our study elucidates important linkages between abiotic and biotic factors, somatic growth, and vital rates, and demonstrates how variation in somatic growth influences temporal and spatial patterns in abundance.
The natural flow regime: A master variable for maintaining river ecosystem health
Authors: Sofi Mohd Sharjeel , Bhat Sami Ullah , Rashid Irfan , Kuniyal Jagdish Chandra 
Published: August 2020

AbstractRiver health is sustained by time‐based variation in their flows, and the maintenance of natural flow regime is essential for keeping the rivers healthy. However, the dynamism in natural flow regime now stands altered by changing climate, and the omnipresent regulation of river flows throughout the world has severely impacted the river health. It is well documented that harnessing and altering the flow of the rivers and streams comes at a huge cost. Numerous rivers in the world have stopped supporting socially and economically important native species or sustain vibrant ecosystems that offer valuable goods and services. The alteration of the natural flow regime has led to the collapse of many healthy and resilient river ecosystems throughout the world. Therefore, to ensure appropriate naturalized flow regimes for riverine organisms and a sustainable nexus between energy demand, water requirements and climate, more understanding is required to study the consequences of alteration in natural flow regime triggered by climate change and anthropogenic interventions. Moreover, conservation and management practices must be firmly based on scientific principles to restore the integrity of river ecosystems. The current approaches often fail to take into consideration a basic fundamental principle that the integrity of the river ecosystem is largely determined by the natural dynamic character of their flow regimes. In this synthesis, we try to explain how the maintenance of the natural flow regime is an essential requirement for maintaining river ecosystem health.
Methodological trends and perspectives of animal dietary studies by noninvasive fecal DNA metabarcoding
Authors: Ando Haruko , Mukai Haruka , Komura Taketo , Dewi Tungga , Ando Masaki , Isagi Yuji 
Published: August 2020

AbstractFine‐scale estimation of trophic interactions is an important subject in the field of ecology. Diet analysis based on fecal DNA metabarcoding has been accepted as a noninvasive, accurate, and time‐ and cost‐effective tool to determine animal diets. Here, we summarize the trends of fecal metabarcoding studies as well as methodological characteristics using 155 original papers published from 2009 to March 2020. We calculated the frequencies of the methods and conditions used in each experimental procedure and bioinformatics approach. Mammals were the major target taxa for fecal metabarcoding. A few methods or conditions dominated each procedure: sampling, DNA extraction, PCR, sequencing, and bioinformatics, which might be specialized for metabarcoding of degraded fecal DNA. However, the disadvantages of common methods were noted in some studies, and further optimizations are required to obtain more accurate dietary data with high taxonomic resolution and quantitative performance. This review will help fecal metabarcode users, especially new scientists who are considering using fecal metabarcoding in their studies, understand the process and common methods of fecal metabarcoding. We also hope this review will facilitate further technical improvements in this method.
A combined bioinformatics, experimental and clinical approach to identify novel cardiac‐specific heart failure biomarkers: is Dickkopf‐3 (DKK3) a possible candidate?
Authors: Piek Arnold , Suthahar Navin , Voors Adriaan A. , de Boer Rudolf A. , Silljé Herman H.W. 
Published: August 2020

ABSTRACTAimsCardiac specificity provides an advantage in correlating heart failure (HF) biomarker plasma levels with indices of cardiac function and remodelling, as shown for natriuretic peptides. Using bioinformatics, we explored the cardiac specificity of secreted proteins and investigated in more detail the relationship of Dickkopf‐3 (DKK3) gene expression and DKK3 plasma concentrations with cardiac function and remodelling in (pre)clinical studies.Methods and resultsThe cardiac specificity of secreted proteins was determined using RNAseq data for a large panel of organs and tissues. This showed that natriuretic peptides (NPPA and NPPB) are highly cardiac‐specific (>99%), whereas other HF biomarkers, including galectin‐3 (Gal‐3, LGALS3) and growth differentiation factor‐15 (GDF‐15), lack cardiac specificity (<4%). DKK3 was cardiac‐enriched (44%), warranting further investigation. In three different HF mouse models, cardiac Dkk3 expression was altered, but DKK3 plasma concentrations were not. In humans, DKK3 plasma concentrations were higher in HF patients (n = 2090) in comparison with age‐ and sex‐matched controls without HF (n = 240) (46.4 ng/mL vs. 36.3 ng/mL; P < 0.001). Multivariate regression analysis revealed that DKK3 was strongly associated with HF risk factors and comorbidities, including age, kidney function and atrial fibrillation. After correction for existing prediction models, DKK3 did not independently predict HF outcome [all‐cause mortality/HF hospitalization, hazard ratio 1.13 (0.79–1.61) per DKK3 doubling; P = 0.503].ConclusionsOf actively secreted HF biomarkers, only natriuretic peptides showed high cardiac specificity. Despite a cardiac specificity of 44%, secreted DKK3 had limited additional diagnostic and prognostic value.
SPEEK/ZnO Nanocomposite Modified Gold Electrode for Electrochemical Detection of Dopamine
Authors: Fayemi Omolola E. , Baskar R. , Adekunle Abolanle S. , Sherif El‐Sayed M. , Ebenso Eno E. 
Published: August 2020

AbstractDrop casting method was used for the fabrication of modified electrode of sulphonated polyether ether ketone/zinc oxide (SPEEK/ZnO) nanocomposite on gold electrode for electrochemical oxidation of dopamine. The SPEEK/ZnO nanocomposites were characterized by using fourier transform infrared (FT‐IR), and Uv‐Vis, while the surface morphology was assessed by scanning electron microscopy (SEM). Elemental composition was determined using Electron dispersive spectroscopic (EDS). The electrocatalysis of dopamine at gold electrode (Au) modified with SPEEK/ZnO nanocomposites in 0.1 M phosphate buffer solution (PBS at pH 7) was examined using cyclic voltammetry. The result obtained at Au/SPEEK/ZnO modified electrode was compared with those obtained at the bare Au and Au/SPEEK nanocomposite modified electrodes. It was found that the ZnO nanoparticles increased the electroactivity of SPEEK towards dopamine oxidation. The Au/SPEEK/ZnO electrode exhibited good linear plot for the concentration range from 5.4×10−13 M to 1.9×10−9 M, with a limit of detection and sensitivity values of 0.89 nM and 18.47 μA mM−1 cm−2 respectively. The modified Au/SPEEK/ZnO also gave distinct separated peaks for dopamine and ascorbic acid in a mixture of both analytes. Also a satisfactory stability result was recorded for the Au/SPEEK/ZnO modified electrode when stored at room temperature for several days. The electrode was successfully used to assay dopamine in real life sample.
Silsesquioxane Modified with PAMAM Dendrimer and a Bimetallic Complex for Electrochemical Detection of Ascorbic Acid
Authors: Silvestrini Fernandes Daniela , do Carmo Devaney Ribeiro 
Published: August 2020

AbstractOctakis(3‐chloropropyl)octasilsesquioxane (S) was organofunctionalized with the PAMAM Dendrimer G.0 (SPD). After functionalization, silsesquioxane interacts with copper chloride and subsequently with potassium hexacyanoferrate (III) to produce the structure CuHSPD. The silsesquioxane functionalized with the PAMAM dendrimer (SPD) and the obtained novel hybrid composite (CuHSPD) were characterized by Fourier transform infrared spectroscopy (FT‐IR), scanning electron microscopy (SEM), and energy dispersive X‐ray spectroscopy (EDS). The CuHSP voltammogram showed two well‐defined redox pairs with Eθ′= 0.27 and 0.74 V, that are assigned to the CuI/CuII and FeII(CN)6/FeIII(CN)6 redox pairs, respectively. The graphite paste electrode containing CuHSPD allowed the electrocatalytic determination of ascorbic acid using various electrochemical techniques such as cyclic voltammetry, differential pulse voltammetry, and chronoamperometry.