bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrological and environmental variables outperform spatial factors in structuring species, trait composition, and beta diversity of pelagic algae
Authors: Wu Naicheng , Qu Yueming , Guse Björn , Makarevičiūtė Kristė , To Szewing , Riis Tenna , Fohrer Nicola 
Published: February 2018

AbstractThere has been increasing interest in algae‐based bioassessment, particularly, trait‐based approaches are increasingly suggested. However, the main drivers, especially the contribution of hydrological variables, of species composition, trait composition, and beta diversity of algae communities are less studied. To link species and trait composition to multiple factors (i.e., hydrological variables, local environmental variables, and spatial factors) that potentially control species occurrence/abundance and to determine their relative roles in shaping species composition, trait composition, and beta diversities of pelagic algae communities, samples were collected from a German lowland catchment, where a well‐proven ecohydrological modeling enabled to predict long‐term discharges at each sampling site. Both trait and species composition showed significant correlations with hydrological, environmental, and spatial variables, and variation partitioning revealed that the hydrological and local environmental variables outperformed spatial variables. A higher variation of trait composition (57.0%) than species composition (37.5%) could be explained by abiotic factors. Mantel tests showed that both species and trait‐based beta diversities were mostly related to hydrological and environmental heterogeneity with hydrological contributing more than environmental variables, while purely spatial impact was less important. Our findings revealed the relative importance of hydrological variables in shaping pelagic algae community and their spatial patterns of beta diversities, emphasizing the need to include hydrological variables in long‐term biomonitoring campaigns and biodiversity conservation or restoration. A key implication for biodiversity conservation was that maintaining the instream flow regime and keeping various habitats among rivers are of vital importance. However, further investigations at multispatial and temporal scales are greatly needed.
A Fluidic Vibrational Energy Harvester for Implantable Medical Device Applications
Authors: INOUE SATOSHI , TAKAHASHI TAKUYA , KUMEMURA MOMOKO , ISHIBASHI KAZUNORI , FUJITA HIROYUKI , HASHIGUCHI GEN , TOSHIYOSHI HIROSHI 
Published: February 2018

SUMMARYIn this paper, we report on a proof‐of‐concept level energy harvester device that could earn electric power of 0.093 μW/cm2 by the fluidic motion in a polydimethylsiloxane microfluidic channel placed on a silicon substrate with built‐in permanent electrical charges or so‐called electrets. Targeting implantable medical devices such as respiratory pacemaker, the heart beat or aspiration is thought to be the source of motion as a final shape of the energy harvesting system.
Multiscale Structured Particle‐Based Zinc Anodes in Non‐Stirred Alkaline Systems for Zinc–Air Batteries
Authors: Titscher Paul , Riede Jens‐Christian , Wiedemann Janosch , Kunz Ulrich , Kwade Arno 
Published: February 2018

AbstractPrimary zinc–air batteries are well established in the commercial market, but secondary zinc–air batteries still suffer from challenging problems. Multiple charge and discharge cycles result in zinc density migration and the formation of passivating by‐products, which can ultimately change the shape of the zinc anode. This work focuses on the use of zinc particles in combination with highly structured current collectors in a cell with a stagnant alkaline electrolyte. Copper weave and copper foam were used as current collectors. The influences of the zinc particle size, the mass loading and the macroscopic structure of the anodes were characterized. Highly structured electrode designs led to improved discharge and cycling performances. Due to the increased active surface area, the electrodes take advantage of highly distributed zinc deposits. The results reveal that the use of multiscale structures within the zinc anode can be beneficial for further applications.
Less of a bird's song than a hard rock ensemble
Authors: Hosfield Robert , Cole James , McNabb John 
Published: February 2018

AbstractCorbey et al. (2016) propose that the Acheulean handaxe was, at least in part, under genetic control. An alternative perspective is offered here, focusing on the nature of the Acheulean handaxe and the archaeological record, and re‐emphasizing their status as cultural artefacts. This is based on four main arguments challenging the proposals of Corbey et al. Firstly, handaxes do not have to track environmental variation to be a cultural artefact, given their role as a hand‐held butchery knife or multi‐purpose tool. Secondly, while handaxe shapes do cluster around a basic bauplan, there is also significant variability in the Acheulean handaxe record, characterized by site‐specific modal forms and locally expressed, short‐lived, idiosyncratic traits. Critically, this variability occurs in both time and space, is multi‐scalar, and does not appear to be under genetic control. Thirdly, handaxes were produced in social contexts, within which their makers grew up exposed to the sights and sounds of artefact manufacture. Finally, the localized absences of handaxes at different times and places in the Lower Paleolithic world is suggestive of active behavioral choices and population dynamics rather than genetic controls.
Building Information Modelling in mechanised shield tunnelling – A practitioner's outlook to the near future
Authors: Stascheit Janosch , Ninić Jelena , Meschke Günther , Hegemann Felix , Maidl Ulrich 
Published: February 2018

AbstractThe contribution takes a glance at the application of BIM technologies in the design and construction phases of shield tunnelling projects. The intention is to show how Building Information Modelling can be translated into actual benefit, not only in the operation phase but also in the design and construction phases of bored tunnels. Emphasising the integrative character of referencing data uniformly in space and time, examples are given of seamless communication between 3D geometrical modelling, efficient numerical simulation and model adaptation based on measured data acquired during the boring process. The article covers the complete range from predesign through structural analysis and detailed design until the actual excavation process including its interactions with the environment. Special emphasis is given to data management, which is the key to transforming a mere 3D visualisation into a Building Information Model. The article therefore presents a concept for database‐supported, web‐based integration of software modules for geometrical modelling in various levels of detail, efficient numerical simulation tools that are based upon this representation, and process controlling that manages all data acquired during the construction process in a spatially and temporally coordinated reference system.
Metro Doha Green Line – More than 30 km of tunnel in 18 months
Authors: Rengshausen Rainer , Weiner Thorsten 
Published: February 2018

AbstractThe capital of Qatar, Doha is being increasingly turned into a modern centre for industry, trade and sport. One essential precondition for this is the development of high‐capacity infrastructure with modern means of transport. This includes the construction of an underground railway network, which has to be completed in a very short time due to the football World Cup taking place in Qatar in 2022. The (part) project ”Metro Green Line Underground“ was awarded in summer 2013 to a Joint Venture comprised of Porr (lead), the Saudi Binladin Group and the local construction company HBK. It includes the turnkey completion of the underground part of the Green Line in the future underground system. This includes two tunnels with a length of 17 km each, six stations, crossover structures, several emergency exits and 32 cross passages and two road underpasses. The shield drive for the running tunnels began in late summer 2014 and could be completed after only 18 months of construction time in early 2016. In addition to explaining how the simultaneous operation of six EPB machines was successfully mastered, this article also describes the conventional tunnelling of the various connection and underpass structures under inner‐city conditions.
A simple mathematical model capable of describing the microbial production of poly(hydroxyalkanoates) under carbon‐ and nitrogen‐limiting growth conditions
Authors: Vega Roberto , Castillo Augusto 
Published: February 2018

AbstractBACKGROUNDPoly(hydroxyalkanoates) (PHAs) are biodegradable polymers that can replace conventional plastics, but microbial production of PHAs must be optimized for commercial success. The aim of this study is to provide a simple mathematical model based on previous studies in the literature to represent the production of PHAs in chemostat and batch cultures by Pseudomonas putida GPo1 (ATCC 29347) and Cupriavidus necator (DSM 545) grown on octanoate and glucose, respectively.RESULTSKinetic and stoichiometric equations, dependent on the specific growth rate of residual biomass (µR), were developed for carbon‐ and nitrogen‐limiting growth conditions. The parameters have biochemical significance and are independent of the biomass concentration. The results revealed that the Luedeking–Piret model is growth‐associated for both fermentations under carbon limitation. In addition, the PHA content increases with µR. Meanwhile, the PHA content is amplified under nitrogen limitation but decreases as μR increases. Also, the Luedeking–Piret model exhibits a profile that depends on the synthesized polyhydroxyalkanoate.CONCLUSIONThis study demonstrates that strategies for the production of PHAs require an in‐depth understanding of the process kinetics. This model gives satisfactory predictions, may be extended to fed batch cultures and may be adapted to other fermentations. © 2018 Society of Chemical Industry
Anthropogenic impact in the Maya Lowlands of Petén, Guatemala, during the last 5500 years
Authors: Battistel D. , Roman M. , Marchetti A. , Kehrwald N. M. , Radaelli M. , Balliana E. , Toscano G. , Barbante C. 
Published: February 2018

ABSTRACTTrace and rare earth elements from a sediment core from Lake Petén Itzá (Guatemala) depict the geochemical dynamics affecting the lake from ∼5500 a BP to the present. This timing encompasses the Preclassic (4000–1700 a BP) and Classic Periods (1700−1000 a BP) when thriving Maya societies extensively cleared land for agriculture. We demonstrate that this land use occurred during times of increased precipitation, where both processes resulted in increased erosion. Rare earth element ratios depict high precipitation rates between 3000 and 1000 a BP, correlating with an increase in allochthonous silicate input and low organic carbon in the ‘Maya Clay’ stratigraphic section, where this layer is ascribed to intensive anthropogenic land use. Cesium anomalies provide additional evidence for runoff due to high rainfalls and amplified by anthropogenic impacts. The Petén Itzá core contains anomalous spikes of arsenic and mercury, and these peaks correspond to documented volcanic eruptions and therefore are probably natural. The geochemical composition of sediments and palynological records indicate re‐growth of the forest after ∼900 a BP. This increased forest vegetation coincides with the timing of the decline in Maya agriculture.
Multi‐proxy reassessment of the paleolimnology of Lake Bonneville (western USA) as observed in the restricted Pilot Valley sub‐basin
Authors: Nelson S. T. , Rey K. A. 
Published: February 2018

ABSTRACTLate Pleistocene sediments of pluvial Lake Bonneville of the western USA represent an important archive of climate and paleolimnological processes. Geochemical, mineralogical and diatom records from the Pilot Valley sub‐basin represent a complete multi‐proxy record of the Bonneville cycle, including closed‐basin transgressive, the Bonneville flood, open‐lake and closed‐basin regressive cycles. Diatoms record pH and salinity, and vary from alkalibiontic/brackish (early transgression), alkaliphilous/fresh‐brackish (deep lake) and back to alkalibiontic/brackish (late regression) conditions. Pennate diatoms reveal passage through and back into the euphotic zone due to the penetration of light through the water column supporting an active benthos. As such, the base of the euphotic zone (∼35 m depth) can be established through time. Restriction and evaporation within the Pilot Valley arm of Lake Bonneville during times of shallow water produced very high endogenic carbonate production, an order of magnitude higher than during deep water. This is shown by age–depth relations in the core, major element and isotopic variations, and sediment mineralogy, requiring a major re‐evaluation of the position of the Bonneville flood horizon within the sediments of Pilot Valley. In summary, lacustrine sediments from restricted arms of large pluvial lakes may vary significantly from complementary records from an open basin.
Lipidomic Analysis: From Archaea to Mammals
Authors: Řezanka Tomáš , Kolouchová Irena , Gharwalová Lucia , Palyzová Andrea , Sigler Karel 
Published: February 2018

AbstractLipids are among the most important organic compounds found in all living cells, from primitive archaebacteria to flowering plants or mammalian cells. They form part of cell walls and constitute cell storage material. Their biosynthesis and metabolism play key roles in faraway topics such as biofuel production (third‐generation biofuels produced by microorganisms, e.g. algae) and human diseases such as adrenoleukodystrophy, Zellweger syndrome, or Refsum disease. Current lipidomic analysis requires fast and accurate processing of samples and especially their characterization. Because the number of possible lipids and, more specifically, molecular species of lipids is of the order of hundreds to thousands, it is necessary to process huge amounts of data in a short time. There are two basic approaches to lipidomic analysis: shotgun and liquid chromatography–mass spectometry. Both methods have their pros and cons. This review deals with lipidomics not according to the type of ionization or the lipid classes analyzed but according to the types of samples (organisms) under study. Thus, it is divided into lipidomic analysis of archaebacteria, bacteria, yeast, fungi, algae, plants, and animals.
Extreme isomeric complexity of dissolved organic matter found across aquatic environments
Authors: Hawkes Jeffrey A. , Patriarca Claudia , Sjöberg Per J. R. , Tranvik Lars J. , Bergquist Jonas 
Published: February 2018

AbstractThe natural aquatic environment contains an enormous pool of dissolved reduced carbon, present as ultra‐complex mixtures that are constituted by an unknown number of compounds at vanishingly small concentrations. We attempted to separate individual structural isomers from several samples using online reversed‐phase chromatography with selected ion monitoring/tandem mass spectrometry, but found that isomeric complexity still presented a boundary to investigation even after chromatographic simplification of the samples. However, it was possible to determine that the structural complexity differed among samples. Our results also suggest that extreme structural complexity was a ubiquitous feature of dissolved organic matter (DOM) in all aquatic systems, meaning that this diversity may play similar roles for recalcitrance and degradation of DOM in all tested environments.
Biogeographical distribution of bacterial communities in Changbai Mountain, Northeast China
Authors: Han Dongxue , Wang Ning , Sun Xue , Hu Yanbo , Feng Fujuan 
Published: February 2018

AbstractThe broad‐leaved and Korean pine mixed forest in Changbai Mountain, China is an important component of boreal forest; the area is sensitive to global climate change. To understand spatial distribution patterns of soil bacterial community along elevation, we analyzed the soil bacterial community diversity and composition along an elevational gradient of 699–1177 m in a primitive Korean pine forest in Changbai Mountain using the high‐throughput sequencing. In total, 149,519 optimized sequences were obtained. Bacterial Shannon index increased along elevation from 699 m to 937 m and started to decrease at the elevation of 1,044 m, showing a humpback curve along elevation. Evenness (ACE index) and richness (Chao index) of the soil bacterial community both decreased with elevation (the highest values of 770 and 762 at 699 m and the lowest values of 548 and 539 at 1,177 m, respectively), all the indices are significantly different between elevations. Bacterial composition at phylum and genus levels had some differences between elevations, but the dominant bacterial populations were generally consistent. Beta‐diversity analysis showed a distance‐decay pattern of bacterial community similarity at different samples. Soil physical and chemical properties explained 70.78% of the variation in bacterial community structure (soil pH explained 19.95%), and elevational distance only explained 8.42%. In conclusion, the contemporary environmental disturbances are the critical factors in maintaining the bacterial spatial distribution compared with historical contingencies.
Development of a dual‐energy computed tomography quality control program: Characterization of scanner response and definition of relevant parameters for a fast‐kVp switching dual‐energy computed tomography system
Authors: Nute Jessica L. , Jacobsen Megan C. , Stefan Wolfgang , Wei Wei , Cody Dianna D. 
Published: February 2018

PurposeA prototype QC phantom system and analysis process were developed to characterize the spectral capabilities of a fast kV‐switching dual‐energy computed tomography (DECT) scanner. This work addresses the current lack of quantitative oversight for this technology, with the goal of identifying relevant scan parameters and test metrics instrumental to the development of a dual‐energy quality control (DEQC).MethodsA prototype elliptical phantom (effective diameter: 35 cm) was designed with multiple material inserts for DECT imaging. Inserts included tissue equivalent and material rods (including iodine and calcium at varying concentrations). The phantom was scanned on a fast kV‐switching DECT system using 16 dual‐energy acquisitions (CTDIvol range: 10.3–62 mGy) with varying pitch, rotation time, and tube current. The circular head phantom (22 cm diameter) was scanned using a similar protocol (12 acquisitions; CTDIvol range: 36.7–132.6 mGy). All acquisitions were reconstructed at 50, 70, 110, and 140 keV and using a water‐iodine material basis pair. The images were evaluated for iodine quantification accuracy, stability of monoenergetic reconstruction CT number, noise, and positional constancy. Variance component analysis was used to identify technique parameters that drove deviations in test metrics. Variances were compared to thresholds derived from manufacturer tolerances to determine technique parameters that had a nominally significant effect on test metrics.ResultsIodine quantification error was largely unaffected by any of the technique parameters investigated. Monoenergetic HU stability was found to be affected by mAs, with a threshold under which spectral separation was unsuccessful, diminishing the utility of DECT imaging. Noise was found to be affected by CTDIvol in the DEQC body phantom, and CTDIvol and mA in the DEQC head phantom. Positional constancy was found to be affected by mAs in the DEQC body phantom and mA in the DEQC head phantom.ConclusionA streamlined scan protocol was developed to further investigate the effects of CTDIvol and rotation time while limiting data collection to the DEQC body phantom. Further data collection will be pursued to determine baseline values and statistically based failure thresholds for the validation of long‐term DECT scanner performance.
A real‐time method to simultaneously measure linear energy transfer and dose for proton therapy using organic scintillators
Authors: Alsanea Fahed , Therriault‐Proulx Francois , Sawakuchi Gabriel , Beddar Sam 
Published: February 2018

PurposeCurrently, no detectors are capable of simultaneously measuring dose and linear energy transfer (LET) in real time. In this study, we evaluated the feasibility of exploiting the difference in the response of various organic plastic scintillation detectors to measure LET and dose in therapeutic proton beams. The hypothesis behind this work was that the ratio of the responses of different scintillators exposed to the same proton beam can be used to obtain a LET vs ratio calibration curve that can then be used to infer LET under any other measurement conditions.MethodsWe first used similar scintillators with different ionization quenching factors. LET values for different irradiation conditions were calculated using a validated Monte Carlo model of the proton beam line. The quenching factors in the Birks equation for different scintillators as a function of LET were obtained from measurements in a 100‐MeV pristine proton beam. We then used four different organic scintillation materials — polystyrene (BCF‐12), poly (methyl methacrylate), polyvinyltoluene, and a liquid scintillator — for which the LET response varied with regard to not only quenching but also differences in material density and relative stopping power. We simultaneously exposed the four different organic scintillators and a plane–parallel ion chamber to passively scattered proton beams at fluence‐averaged LET. Comparisons to the expected values obtained from the Monte Carlo simulations were made on the basis of both dose and LET.ResultsThe maximum difference in the quenching factor was 20%, resulting in a 5% change in LET with a response ratio over a range of 5 keV/μm. Among all the scintillators investigated, the ratio of PMMA to BCF‐12 provided the best correlation with LET values and was therefore used to construct the LET calibration curve. The expected LET values in the validation set were within 2% ± 6%, which resulted in dose accuracy of 1.5% ± 5.8% for the range of LET values investigated in this work.ConclusionsWe demonstrated the feasibility of using the ratio of the light outputs of two organic scintillators to simultaneously measure LET and dose in therapeutic proton beams for fluence‐averaged LET values from 0.47 to 1.26 keV/μm. Further studies are needed to verify the response for higher LET values and the reproducibility of this method.