bluuebunny/crossref_metadata_2025_split huggingface dataset:
Piezoelectric Moonie‐type Resonant Microactuator
Authors: FUJIMURA YASUHIRO , TSUKAMOTO TAKASHIRO , TANAKA SHUJI 
Published: January 2018

SUMMARYThis paper reports a piezoelectric in‐plane resonant actuator for a speckle dissolution device used in a laser‐type projector. An optical diffuser is oscillated by this actuator to reduce the coherency of a scanned laser beam. A PZT unimorph actuator combined with a Moonie‐type displacement amplifier and a resonant structure was used to obtain a large displacement. The L18 design of experiment method was used for the optimal design. Both 1‐axis and 2‐axis actuators were designed and fabricated. The maximum displacement as high as 239.5 μm at a resonance frequency of 325.2 Hz was obtained for the 1‐axis actuator, and the maximum displacements of 109.5 μm and 67 μm for l.5 Hz for both x‐ and y‐direction at resonance frequencies of 621.5 Hz and 288.5 Hz were obtained for the 2‐axis actuator (10 V). The actuator was also tested with a dummy optical diffuser to evaluate the influence of the additional mass.
Can sugar maple establish into the boreal forest? Insights from seedlings under various canopies in southern Quebec
Authors: Collin Alexandre , Messier Christian , Kembel Steven W. , Bélanger Nicolas 
Published: January 2018

AbstractUnderstanding tree recruitment dynamics in various growth environments is essential for a better assessment of tree species’ adaptive capacity to climate change. We investigated the microsite factors influencing survival, growth, and foliar nutrition of natural and planted sugar maple seedlings (Acer saccharum) along a gradient of tree species that reflect the change in composition from temperate hardwoods to boreal forests of eastern Canada. We specifically tested whether the increasing abundance of conifers in the forest and its modifications on soil properties negatively affects foliar nutrition of natural seedlings as well as the survival and growth of seedlings planted directly in the natural soil and in pots filled with enriched soil. Results of natural seedlings indicate that under conifer‐dominated stands, lower soil pH, accelerated dissolution of some minerals, lower temperature and moisture, and higher levels of phenolic compounds have created microsites that are less suitable for sugar maple foliar nutrition and regeneration. These conditions were omnipresent under hemlock. The growth of seedlings planted in the natural soil was negatively impacted by the overall low soil quality under all forest types (as compared to seedlings planted in pots with enriched soil). However, survival and growth of the seedlings were not negatively affected by conifers, regardless of planting type, likely because of stored nutrients from the nursery. Also, lower survival was found under maple–birch stands for seedlings planted both in the natural soil and in pots with enriched soil due to higher shading. This study has identified key microsite factors created by specific conifers that may impede or benefit the potential of sugar maple to maintain its current range or expand its range northward under climate change.
Predicting aboveground forest biomass with topographic variables in human‐impacted tropical dry forest landscapes
Authors: Salinas‐Melgoza Miguel A. , Skutsch Margaret , Lovett Jon C. 
Published: January 2018

AbstractTopographic variables such as slope and elevation partially explain spatial variations in aboveground biomass (AGB) within landscapes. Human activities that impact vegetation, such as cattle grazing and shifting cultivation, often follow topographic features and also play a key role in determining AGB patterns, although these effects may be moderated by accessibility. In this study, we evaluated the potential to predict AGB in a rural landscape, using a set of topographical variables in combination with indicators of accessibility. We modeled linear and non‐linear relationships between AGB, topographic variables within the territorial boundaries of six rural communities, and distance to roads. Linear models showed that elevation, slope, topographic wetness index, and tangential curvature could explain up to 21% of AGB. Non‐linear models found threshold values for the relationship between AGB and diffuse insolation, topographic position index at 19 × 19 pixels scale and differentiated between groups of communities, improving AGB predictions to 33%. We also found a continuous and positive effect on AGB with increased distance from roads, but also a piecewise relationship that improves the understanding of intensity of human activities. These findings could enable AGB baselines to be constructed at landscape level using freely available data from topographic maps. Such baselines may be of use in national programs under the international policy Reducing Emissions from Deforestation and Forest Degradation.
Saltmarsh plants, but not fertilizer, facilitate invertebrate recolonization after an oil spill
Authors: Johnson David Samuel , Fleeger John W. , Riggio Maria Rita , Mendelssohn Irving A. , Lin Qianxin , Graham Sean A. , Deis Donald R. , Hou Aixin 
Published: January 2018

AbstractFoundation species contribute to the recovery of animal communities from disturbance by engineering, by improving habitat quality, and by regulating food availability. In a salt marsh impacted by the Deepwater Horizon oil spill, we tested the hypothesis that nutrient subsidies would enhance the positive effects of the foundation species Spartina alterniflora on the initial recolonization of benthic invertebrate communities (e.g., copepods, annelids, nematodes) by augmenting food (i.e., microalgae) availability. After two months, plantings of S. alterniflora significantly elevated the densities of the polychaete Capitella capitata, meiofauna‐sized annelids, and total macroinfauna over unplanted plots. After 7 months, the significant effect of plantings persisted for meiofauna‐sized annelids, but not for C. capitata and total macroinfauna. Plantings had no effect on copepods (including Nannopus palustris, the dominant species), nematodes, or microalgal biomass for either month. Nutrient additions did not influence any taxon, despite initial increases in benthic microalgal biomass after 2 months. We hypothesize that the structural effects of plants were important to early colonization, possibly by facilitating larval settlement or ameliorating temperature and desiccation stress. Our results emphasize the importance of re‐establishing foundation species in oil‐impacted sites to enhance recolonization of saltmarsh annelids, but suggest that recolonization is not promoted by the addition of nutrients.
Experimental droughts with rainout shelters: a methodological review
Authors: Hoover David L. , Wilcox Kevin R. , Young Kristina E. 
Published: January 2018

AbstractForecast increases in the frequency, intensity, and duration of droughts with climate change may have extreme and extensive ecological consequences. There are currently hundreds of published, ongoing, and new drought experiments worldwide aimed to assess ecological sensitivity to drought and identify the mechanisms governing resistance and resilience. To date, the results from these experiments have varied widely, and thus, patterns of drought sensitivities and the underlying mechanisms have been difficult to discern. Here we examined 89 published drought experiments, along with their associated historical precipitation records to (1) identify where and how drought experiments have been imposed, (2) determine the extremity of drought treatments in the context of historical climate, and (3) assess the influence of ambient precipitation variability on the magnitude of drought experiments. In general, drought experiments were most common in water‐limited ecosystems, such as grasslands, and were often short‐term, as 80% were 1–4 yr in duration. When placed in a historical context, the majority of drought experiments imposed extreme drought, with 61% below the 5th, and 43% below the 1st percentile of the 50‐yr annual precipitation distribution. We also determined that interannual precipitation variability had a large and potentially underappreciated effect on the magnitude of drought treatments due to the co‐varying nature of control and drought precipitation inputs. Thus, detecting significant ecological effects in drought experiments is strongly influenced by the interaction between experimental drought magnitude, precipitation variability, and key ecological thresholds. The patterns that emerged from this study have important implications for the design and interpretation of drought experiments and also highlight critical gaps in our understanding of the ecological effects of drought.
Species‐specific spring and autumn leaf phenology captured by time‐lapse digital cameras
Authors: Xie Yingying , Civco Daniel L. , Silander John A. 
Published: January 2018

AbstractPlant leaf phenology is typically observed either via ground‐based visual observations on individuals or via remote sensing of land surface vegetation. To integrate phenological information from both data sources, collected at different spatial scales using different observational protocols, digital cameras were deployed spanning canopy areas with enough spatial resolution to identify temporal changes in individual deciduous tree species with continuous observations. Comparisons of phenology between camera photography and in situ observations have been reported in prior studies; however, it is still unclear that how these camera images relate to field observations at individual and species levels, and how the metrics from those images provide comparable species‐specific phenological responses to environmental variation. We set a suite of digital time‐lapse cameras to acquire continuous photographs of deciduous tree canopies and conducted ground‐based visual observations in Connecticut,USA, from 2012 to 2014. Comparisons between image‐derived dates and observed phenological dates showed that both green and red color indices could be matched to ground observations, and red color indices showed good performance in matching autumn phenology across our group of eight tree species that dominate the southern New England forests. Linear mixed‐effects models were applied to investigate the relationships between climatic/weather conditions and the timing of peak and of intensity of red color in fall foliage for each species. Model results suggested that temperature, precipitation, drought stress in autumn, and heat stress in summer are all important factors to the timing of peak fall foliage color and that higher minimum temperatures (or lower cold degree‐day accumulation) in the autumn are linked to higher intensity of red coloration at least in sugar maples. This study improves our understanding of temporal and spatial variation in the phenology of deciduous trees captured by digital cameras. As well, this provides insights into relating species‐specific information on phenology from visual observations in the field to near‐surface remote sensing and points to the need for further research on autumn phenology using the change in redness of tree canopies.
Competitive ability, stress tolerance and plant interactions along stress gradients
Authors: Qi Man , Sun Tao , Xue SuFeng , Yang Wei , Shao DongDong , Martínez‐López Javier 
Published: January 2018

AbstractExceptions to the generality of the stress‐gradient hypothesis (SGH) may be reconciled by considering species‐specific traits and stress tolerance strategies. Studies have tested stress tolerance and competitive ability in mediating interaction outcomes, but few have incorporated this to predict how species interactions shift between competition and facilitation along stress gradients. We used field surveys, salt tolerance and competition experiments to develop a predictive model interspecific interaction shifts across salinity stress gradients. Field survey and greenhouse tolerance tests revealed tradeoffs between stress tolerance and competitive ability. Modeling showed that along salinity gradients, (1) plant interactions shifted from competition to facilitation at high salinities within the physiological limits of salt‐intolerant plants, (2) facilitation collapsed when salinity stress exceeded the physiological tolerance of salt‐intolerant plants, and (3) neighbor removal experiments overestimate interspecific facilitation by including intraspecific effects. A community‐level field experiment, suggested that (1) species interactions are competitive in benign and, facilitative in harsh condition, but fuzzy under medium environmental stress due to niche differences of species and weak stress amelioration, and (2) the SGH works on strong but not weak stress gradients, so SGH confusion arises when it is applied across questionable stress gradients. Our study clarifies how species interactions vary along stress gradients. Moving forward, focusing on SGH applications rather than exceptions on weak or nonexistent gradients would be most productive.
Low NT‐proBNP levels in overweight and obese patients do not rule out a diagnosis of heart failure with preserved ejection fraction
Authors: Buckley Leo F. , Canada Justin M. , Del Buono Marco G. , Carbone Salvatore , Trankle Cory R. , Billingsley Hayley , Kadariya Dinesh , Arena Ross , Van Tassell Benjamin W. , Abbate Antonio 
Published: January 2018

AbstractBackgroundHeart failure with preserved ejection fraction (HFpEF) is a heterogeneous syndrome that presents clinicians with a diagnostic challenge. The use of natriuretic peptides to exclude a diagnosis of HFpEF has been proposed. We sought to compare HFpEF patients with N‐terminal pro‐brain natriuretic peptide (NT‐proBNP) level above and below the proposed cut‐off.MethodsStable patients (n = 30) with left ventricular (LV) ejection fraction ≥ 50% were eligible if they had a diagnosis of HF according to the European Society of Cardiology diagnostic criteria. Characteristics of patients with NT‐proBNP below (≤125 pg/mL) and above (>125 pg/mL) the diagnostic criterion were compared.ResultsThere were 19 (66%) women with median age 54 years. Half were African American (16, 53%), and most were obese. There were no significant differences in clinical characteristics or medication use between groups. LV end‐diastolic volume index was greater in high NT‐proBNP patients (P = 0.03). Left atrial volume index, E/e′ ratio, and E/e′ ratio at peak exercise were not significantly different between NT‐proBNP groups. Peak oxygen consumption (VO2), VO2 at ventilatory threshold, and ventilatory efficiency measures were impaired in all patients and were not significantly different between high and low NT‐proBNP patients.ConclusionsNT‐proBNP was below the proposed diagnostic cut‐off point of 125 pg/mL in half of this obese study cohort. Cardiac diastolic dysfunction and cardiorespiratory fitness were not significantly different between high and low NT‐proBNP patients. These data indicate that excluding the diagnosis of HFpEF based solely on NT‐proBNP levels should be discouraged.
Eligibility of sacubitril–valsartan in a real‐world heart failure population: a community‐based single‐centre study
Authors: Norberg Helena , Bergdahl Ellinor , Lindmark Krister 
Published: January 2018

AbstractAimsThis study aims to investigate the eligibility of the Prospective Comparison of Angiotensin Receptor–Neprilysin Inhibitor (ARNI) with ACE inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure (PARADIGM‐HF) study to a real‐world heart failure population.Methods and resultsMedical records of all heart failure patients living within the catchment area of Umeå University Hospital were reviewed. This district consists of around 150 000 people. Out of 2029 patients with a diagnosis of heart failure, 1924 (95%) had at least one echocardiography performed, and 401 patients had an ejection fraction of ≤35% at their latest examination. The major PARADIGM‐HF criteria were applied, and 95 patients fulfilled all enrolment criteria and thus were eligible for sacubitril–valsartan. This corresponds to 5% of the overall heart failure population and 24% of the population with ejection fraction ≤ 35%. The eligible patients were significantly older (73.2 ± 10.3 vs. 63.8 ± 11.5 years), had higher blood pressure (128 ± 17 vs. 122 ± 15 mmHg), had higher heart rate (77 ± 17 vs. 72 ± 12 b.p.m.), and had more atrial fibrillation (51.6% vs. 36.2%) than did the PARADIGM‐HF population.ConclusionsOnly 24% of our real‐world heart failure and reduced ejection fraction population was eligible for sacubitril–valsartan, and the real‐world heart failure and reduced ejection fraction patients were significantly older than the PARADIGM‐HF population. The lack of data on a majority of the patients that we see in clinical practice is a real problem, and we are limited to extrapolation of results on a slightly different population. This is difficult to address, but perhaps registry‐based randomized clinical trials will help to solve this issue.
Applying Co3O4@nanoporous Carbon to Nonenzymatic Glucose Biofuel Cell and Biosensor
Authors: Jiao Kailong , Kang Zepeng , Wang Bing , Jiao Shuqiang , Jiang Yu , Hu Zongqian 
Published: January 2018

AbstractA novel hierarchically nanoporous carbon (NPC) derived from Al‐based porous coordination polymer is prepared by two‐step carbonization method for immobilization of the Co3O4 in the application of the nonenzymatic biofuel cells and biosensors. The structure and morphology are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), high‐resolution transmission electron microscopy (HRTEM), and X‐ray diffraction (XRD). Brunauer‐Emmett‐Teller (BET) is to characterize the porous nature of the NPC, and X‐ray photoelectron spectroscopy (XPS) is to characterize the composition of Co3O4@nanoporous carbon (Co3O4@NPC). Without collapse in the high carbonization temperature (above 1600 °C), the NPC maintains the nanoporous structure and high specific surface area of 1551.2 m2 g−1. In addition, the NPC is composited with Co3O4 by hydrothermal method to form the Co3O4@NPC. When tested as the nonenzymatic electrocatalyst for glucose oxidation reaction (GOR), the Co3O4@NPC exhibits higher response to glucose, in which the current shifts up by 64 %, than pure Co3O4 in 0.1 M KOH. The limit of detection is 0.005 mM (S/N=3) and response time is within 3 s. The detection range can be divided into two sections of 0.02–1.4 mM and 1.4–10.7 mM with the sensitivity of 249.1 μA mM−1 cm−2 and 66.6 μA mM−1 cm−2, respectively. A glucose fuel cell is constructed with the Co3O4@NPC as the anode and Pt/C catalyst as the cathode. The open‐circuit potential of the nonenzymatic glucose/O2 fuel cell was 0.68 V, with a maximum power density of 0.52 mW cm−2 at 0.27 V. This work may contribute to exploring other nanoporous carbons for application in glucose fuel cells and biosensors.
A microfluidic chip with a staircase pH gradient generator, a packed column and a fraction collector for chromatofocusing of proteins
Authors: Rho Hoon Suk , Hanke Alexander Thomas , Ottens Marcel , Gardeniers Han J.G.E. 
Published: January 2018

AbstractA microfluidic device for pH gradient chromatofocusing is presented, which performs creation of a micro‐column, pH gradient generation, and fraction collection in a single device. Using a sieve micro‐valve, anion exchange particles were packed into a microchannel in order to realize a solid‐phase absorption column. To fractionate proteins according to their isoelectric points, elution buffer solutions with a stepwise pH gradient were prepared in 16 parallel mixing reactors and flowed through the micro‐column, wherein a protein mixture was previously loaded. The volume of the column is only 20 nL, hence it allows extremely low sample consumption and fast analysis compared with a conventional system. We demonstrated separation of two proteins, albumin–fluorescein isothiocyanate conjugate (FITC‐BSA) and R‐Phycoerythrin (R‐PE), by using a microcolumn of commercial charged polymeric particles (Source 15Q). The microfluidic device can be used as a rapid diagnostic tool to analyse crude mixtures of proteins or nucleic acids and determine adsorption/desorption characteristics of various biochemical products, which can be helpful for scientific fundamental understanding as well as instrumental in various industrial applications, especially in early stage screening and process development.
Joint optimal power allocation, cooperative beamforming, and jammer selection design to secure untrusted relaying network
Authors: Moradikia Majid , Mashdour Saeed , Jamshidi Ali 
Published: January 2018

AbstractA half‐duplex relaying network provides 2 opportunities for passive eavesdroppers (Eves) and 1 opportunity for untrusted relays to intercept the information. In this paper, we aim to enhance the physical layer security of a cooperative network where a single‐antenna source intends to communicate with a single‐antenna destination in the presence of a group of untrusted relays and a passive eavesdropper. The objective is to protect the data confidentially while concurrently relying on the untrusted relays as potential Eves to improve both the security and reliability of the network. To realize this objective, we design a joint cooperative beamforming and cooperative jamming strategy. With the aim of maximizing the instantaneous secrecy rate, an optimal power allocation (OPA) scheme is proposed where the transmission powers of both jammer and source are optimized simultaneously under the total power budget constraint. To further improve the secrecy rate, a jammer selection strategy is also proposed where cooperative jamming is performed by the destination or one of the idle relays. For the proposed scheme, a closed‐form expression of beamformer vector is derived by solving a generalized eigenvalue problem. Finally, for the OPA problem, it is possible to be neither convex nor concave. In this regard, all possible cases are investigated to determine the OPA factor accurately. Numerical results illustrate that the proposed joint OPA–cooperative beamforming scheme, together with the most appropriate jammer selection strategy, significantly increases the secrecy rate.
Young children show more vigilance against individuals with poor knowledge than those with antisocial motives
Authors: Vanderbilt Kimberly E. , Heyman Gail D. , Liu David 
Published: January 2018

AbstractIn three experiments, the present research investigated whether children's distrust of unreliable informants was influenced by the type of mental state causing the informants' unreliability. Children (total N = 167) played a searching game with an informant who repeatedly provided incorrect information either due to poor knowledge or to intentional deception resulting from antisocial motives. Results of Experiment 1 showed that children initially distrusted the ignorant informant more than the deceptive informant, but that levels of distrust increased and converged after children received feedback on their responses. Experiment 2 replicated the findings of Experiment 1 and also extended them by showing that children consistently distrusted the ignorant informant more than the deceptive informant in the absence of feedback. Experiment 3 helped rule out the possibility that results could be explained by the wording of informant descriptions in Experiments 1 and 2. Taken together, our results contribute to a small body of findings suggesting that young children have the capacity to use mental state information to make selective trust judgments and suggest that young children show more vigilance against individuals with poor knowledge than those with antisocial motives.Highlights

How does the type of mental state causing unreliability (either ignorance or antisocial motives) influence children's vigilance against unreliable sources?
A direct comparison showed that children (3 ‐ 4 years old) distrusted ignorant sources more than antisocial sources.
Children use mental state information to make selective trust judgements.