bluuebunny/crossref_metadata_2025 huggingface dataset:
Biological and Molecular Characterization of Trypanosoma cruzi Strains from Four States of Brazil
Authors: Ribeiro Aline Rimoldi , Lima Luciana , de Almeida Larissa Aguiar , Monteiro Joana , Moreno Cláudia Jassica Gonçalves , Nascimento Juliana Damieli , de Araújo Renato Freitas , Mello Fernanda , Martins Luciamáre Perinetti Alves , Graminha Márcia Aparecida Silva , Teixeira Marta Maria Geraldes , Silva Marcelo Sousa , Steindel Mário , da Rosa João Aristeu
Published: January 2018

Chagas disease affects between six and seven million people. Its etiological agent, Trypanosoma cruzi, is classified into six discrete typing units (DTUs). The biological study of 11 T. cruzi strains presented here included four parameters: growth kinetics, parasitemia curves, rate of macrophage infection, and serology to evaluate IgM, total IgG, IgG1, IgG2a, and IgG3. Sequencing of small subunit of ribosomal RNA (SSU rRNA)was performed and the T. cruzi strains were classified into three DTUs. When their growth in liver infusion tryptose medium was represented in curves, differences among the strains could be noted. The parasitemia profile varied among the strains from the TcI, TcII, and TcIII groups, and the 11 T. cruzi strains produced distinct parasitemia levels in infected BALB/c. The TcI group presented the highest rate of macrophage infection by amastigotes, followed by TcII and TcIII. Reactivity to immunoglobulins was observed in the TcI, TcII, and TcIII; all the animals infected with the different strains of T. cruzi showed anti-T. cruzi antibodies. The molecular study presented here resulted in the classification of the T. cruzi strains into the TcI (Bolivia, T lenti, Tm, SC90); TcII (Famema, SC96, SI8, Y); and TcIII (QMM3, QMM5, SI5) groups. These biological and molecular results from 11 T. cruzi strains clarified the factors involved in the biology of the parasite and its hosts. The collection of triatomine (vector) species, and the study of geographic distribution, as well as biological and molecular characterization of the parasite, will contribute to the reporting and surveillance measures in Brazilian states.
1.5 Tesla Magnetic Resonance Imaging to Investigate Potential Etiologies of Brain Swelling in Pediatric Cerebral Malaria
Authors: Potchen Michael J. , Kampondeni Samuel D. , Seydel Karl B. , Haacke E. Mark , Sinyangwe Sylvester S. , Mwenechanya Musaku , Glover Simon J. , Milner Danny A. , Zeli Eric , Hammond Colleen A. , Utriainen David , Lishimpi Kennedy , Taylor Terrie E. , Birbeck Gretchen L.
Published: January 2018

The hallmark of pediatric cerebral malaria (CM) is sequestration of parasitized red blood cells in the cerebral microvasculature. Malawi-based research using 0.35 Tesla (T) magnetic resonance imaging (MRI) established that severe brain swelling is associated with fatal CM, but swelling etiology remains unclear. Autopsy and clinical studies suggest several potential etiologies, but limitations of 0.35 T MRI precluded optimal investigations into swelling pathophysiology. A 1.5 T MRI in Zambia allowed for further investigations including susceptibility-weighted imaging (SWI). SWI is an ideal sequence for identifying regions of sequestration and microhemorrhages given the ferromagnetic properties of hemozoin and blood. Using 1.5 T MRI, Zambian children with retinopathy-confirmed CM underwent imaging with SWI, T2, T1 pre- and post-gadolinium, diffusion-weighted imaging (DWI) with apparent diffusion coefficients and T2/fluid attenuated inversion recovery sequences. Sixteen children including two with moderate/severe edema were imaged; all survived. Gadolinium extravasation was not seen. DWI abnormalities spared the gray matter suggesting vasogenic edema with viable tissue rather than cytotoxic edema. SWI findings consistent with microhemorrhages and parasite sequestration co-occurred in white matter regions where DWI changes consistent with vascular congestion were seen. Imaging findings consistent with posterior reversible encephalopathy syndrome were seen in children who subsequently had a rapid clinical recovery. High field MRI indicates that vascular congestion associated with parasite sequestration, local inflammation from microhemorrhages and autoregulatory dysfunction likely contribute to brain swelling in CM. No gross radiological blood brain barrier breakdown or focal cortical DWI abnormalities were evident in these children with nonfatal CM.
Malaria and Iron Load at the First Antenatal Visit in the Rural South Kivu, Democratic Republic of the Congo: Is Iron Supplementation Safe or Could It Be Harmful?
Authors: Bahizire Esto , D’Alessandro Umberto , Dramaix Michèle , Dauby Nicolas , Bahizire Fabrice , Mubagwa Kanigula , Donnen Philippe
Published: January 2018

We investigated the relationship between malaria infection and iron status in 531 pregnant women in South Kivu, Democratic Republic of the Congo. Sociodemographic data, information on morbidity, and clinical data were collected. A blood sample was collected at the first antenatal visit to diagnose malaria and measure serum ferritin (SF), soluble transferrin receptor, C-reactive protein, and α1-acid-glycoprotein. Malaria prevalence was 7.5%. Median (interquartile range) SF (adjusted for inflammation) was significantly higher in malaria-infected (82.9 μg/L [56.3–130.4]) than in non-infected (39.8 μg/L [23.6–60.8]) women (P < 0.001). Similarly, estimated mean body iron store was higher in malaria-infected women (P < 0.001). Malaria was significantly and independently associated with high levels of SF. Efforts to improve malaria prevention while correcting iron deficiency and anemia during pregnancy are warranted.
Epidemiological, Serological, and Virological Features of Dengue in Nha Trang City, Vietnam
Authors: Quyen Duong Le , Thanh Le Nguyen , Van Anh Cao Thi , Nguyen Nguyen Binh , Hoang Dong Van , Montgomery Jacqui L. , Kutcher Simon C. , Hoang Le Nguyen , Hien Nguyen Tran , Hue Kien Duong Thi , Rabaa Maia , O’Neill Scott L. , Simmons Cameron P. , Anh Dang Duc , Anders Katherine L.
Published: January 2018

Vietnam is endemic for dengue. We conducted a series of retrospective and prospective studies to characterize the epidemiology of dengue and population mobility patterns in Nha Trang city, Vietnam, with a view to rational design of trials of community-level interventions. A 10-year time series of dengue case notifications showed pronounced interannual variability, as well as spatial heterogeneity in ward-level dengue incidence (median annual coefficient of variation k = 0.47). Of 451 children aged 1–10 years enrolled in a cross-sectional serosurvey, almost one-third had evidence of a past dengue virus (DENV) infection, with older children more likely to have a multitypic response indicative of past exposure to ≥ 1 serotype. All four DENV serotypes were detected in hospitalized patients during 8 months of sampling in 2015. Mobility data collected from 1,000 children and young adults via prospective travel diaries showed that, although all ages spent approximately half of their daytime hours (5:00 am–9:00 pm) at home, younger age groups (≤ 14 years) spent a significantly greater proportion of their time within 500 m of home than older respondents. Together these findings inform the rational design of future trials of dengue preventive interventions in this setting by identifying 1) children < 7 years as an optimal target group for a flavivirus-naive serological cohort, 2) children and young adults as the predominant patient population for a study with a clinical end point of symptomatic dengue, and 3) substantial spatial and temporal variations in DENV transmission, with a consequent requirement for a trial to be large enough and of long enough duration to overcome this heterogeneity.
Reptiles and Amphibians as Potential Reservoir Hosts of Chikungunya Virus
Authors: Bosco-Lauth Angela M. , Hartwig Airn E. , Bowen Richard A.
Published: January 2018

Chikungunya virus is an emerging arbovirus of significant human-health concern. Little is known about its sylvatic cycle, including whether ectothermic vertebrates are permissive to infection. In this study, individuals from ten species of reptiles and amphibians were inoculated with chikungunya virus and samples of blood were tested to characterize viremia and seroconversion. Viremia was not detected in cane toads, house geckos, or American alligators, but most of the green iguanas, red-eared sliders, ball and Burmese pythons, leopard frogs, Texas toads, and garter snakes developed viremia. Peak virus titers in serum of up to 4.5, 4.7, and 5.1 log10 plaque-forming units per milliliter were observed for garter snakes, ball pythons, and Texas toads, respectively. These results add to those of other studies that have suggested a possible role for ectothermic vertebrates in the ecology of arbovirus maintenance and transmission in nature.
The Δ17O and δ18O values of simultaneously collected atmospheric nitrates from anthropogenic sources – Implications for polluted air masses
Authors: Savard Martine M. , Cole Amanda , Vet Robert , Smirnoff Anna
Published: January 2018

Abstract. There are clear motivations for better understanding the atmospheric processes that transform nitrogen (N) oxides (NOx) emitted from anthropogenic sources into nitrates (NO3−), two of them being that NO3− contributes to acidification and eutrophication of terrestrial and aquatic ecosystems, and particulate nitrate may play a role in climate dynamics. For these reasons, oxygen isotope ratios (δ18O, Δ17O) have been applied to infer the chemical pathways leading to the observed distribution of wet (w-NO3−), particulate (p-NO3−), and the sum of p-NO3− and gaseous HNO3, while the gaseous form (HNO3) has never been separately characterized for 17O. Previous research studies have investigated w-NO3−, p-NO3− or p-NO3− + HNO3 from non-polluted or polluted air masses, and inferred seasonal changes in the dominance of oxidation pathways to account for higher δ18O and Δ17O values in winter relative to summer. However, none of the polluted air studies collected samples specific to targeted emission sources. Here we have used a wind-sector-based, multi-stage filter sampling system and precipitation collector to simultaneously sample HNO3 and p-NO3−, and co-collect w-NO3−, downwind from five different anthropogenic sources. Overall, the w- and p-NO3 δ18O and Δ17O values show expected differences between cold and warm seasons, but only the Δ17O values of HNO3 follow this pattern. The HNO3 δ18O ranges are distinct from the w- and p-NO3− patterns. Interestingly, the Δ17O differences between p-NO3− and HNO3 shifts from positive during cold sampling periods to negative during warm periods. The summer pattern may be due to the presence of nitrates derived from NOx that has not yet reached isotopic equilibrium with O3 and subsequent differences in dry deposition rates, while the larger proportion of p-NO3− formed via the N2O5 pathway can explain the fall-winter pattern. Very low p-NO3− Δ17O values observed during warm months may be due to this non-equilibrated NOx, though contribution from RO2 oxidation remains a possibility. Our results show that the isotopic signals of HNO3, w-NO3− and p-NO3− are not interchangeable and that their differences can further our understanding of NOx oxidation and deposition. Future research should investigate all tropospheric nitrate species as well as NOx to refine our understanding of nitrate worldwide and to develop effective emission reduction strategies.
Aerosol chemistry and particle growth events at an urban downwind site in the North China Plain
Authors: Zhang Yingjie , Du Wei , Wang Yuying , Wang Qingqing , Wang Haofei , Zheng Haitao , Zhang Fang , Shi Hongrong , Bian Yuxuan , Han Yongxiang , Fu Pingqing , Canonaco Francesco , Prévôt André S. H. , Zhu Tong , Wang Pucai , Li Zhanqing , Sun Yele
Published: January 2018

Abstract. The North China Plain (NCP) has experienced frequent severe haze pollution events in recent years. While extensive measurements have been made in megacities, aerosol sources, processes, and particle growth at urban downwind sites remain less understood. Here, an Aerosol Chemical Speciation Monitor and a Scanning Mobility Particle Sizer, along with a suite of collocated instruments, were deployed at the downwind site of Xingtai, a highly polluted city in the NCP, for real-time measurements of submicron aerosol (PM1) species and particle number size distributions during May and June 2016. The average mass concentration of PM1 was 30.5 (±19.4) μg m−3, which is significantly lower than that during wintertime. Organic aerosols (OA) constituted the major fraction of PM1 (38 %) followed by sulfate (25 %) and nitrate (14 %). Positive matrix factorization with the Multilinear Engine version 2 showed that oxygenated OA (OOA) was the dominant species in OA throughout the study, on average accounting for 78 % of OA, while traffic and cooking emissions both accounted for 11 % of OA. Our results highlight that aerosol particles at the urban downwind site were highly aged and mainly from secondary formation. However, the diurnal cycle also illustrated the substantial influence of urban emissions on downwind sites, which are characterized by similar pronounced early morning peaks for most aerosol species. New particle formation and growth events were also frequently observed (58 % of the time) on both clean and polluted days. Particle growth rates varying from 1.2 to 4.9 nm h−1 were positively related to the condensation sink during periods with high OOA contributions and also to sulfate concentrations during relatively clean periods. Our results showed that sulfate and OOA played important roles in particle growth during clean periods, while OOA was more important than sulfate during polluted events. Further analyses showed that particle growth rates have no clear dependence on air mass trajectories.
Calculating uncertainty for the RICE ice core continuous flow analysis water isotope record
Authors: Keller Elizabeth D. , Baisden W. Troy , Bertler Nancy A. N. , Emanuelsson B. Daniel , Canessa Silvia , Phillips Andy
Published: January 2018

Abstract. We describe a novel approach to the calibration and uncertainty estimation of a high-resolution continuous flow analysis (CFA) water isotope (δ2H, δ18O) record from the Roosevelt Island Climate Evolution (RICE) Antarctic ice core. Our method establishes robust uncertainty estimates for CFA δ2H and δ18O measurements, comparable to those reported for discrete sample δ2H and δ18O analysis. Data were calibrated using a time-weighted two-point linear calibration with two standards measured both before and after continuously melting three or four meters of ice core. The error at each data point was calculated as the quadrature sum of three factors: Allan variance, scatter over the averaging interval, and general calibration accuracy. Final mean total error for the entire record is δ2H = 0.74 ‰ and δ18O = 0.21 ‰. The quality over the length of the dataset is variable, likely due to a combination of poorer ice quality at lower depths, interruptions in the CFA measurements due to ice breaks and equipment failure, the build-up over time of residual drill fluid, and leaks or valve degradation in the system. Despite the somewhat uneven system performance, this represents a significant achievement in precision of high-resolution CFA water isotope measurement.
A highly miniaturized satellite payload based on a spatial heterodyne spectrometer for atmospheric temperature measurements in the mesosphere and lower thermosphere
Authors: Kaufmann Martin , Olschewski Friedhelm , Mantel Klaus , Solheim Brian , Shepherd Gordon , Deiml Michael , Liu Jilin , Song Rui , Chen Qiuyu , Wroblowski Oliver , Wei Daikang , Zhu Yajun , Wagner Friedrich , Loosen Florian , Froehlich Denis , Neubert Tom , Rongen Heinz , Knieling Peter , Toumpas Panos , Shan Jinjun , Tang Geshi , Koppmann Ralf , Riese Martin
Published: January 2018

Abstract. A highly miniaturized limb sounder for the observation of the O2 A-Band to derive temperatures in the mesosphere and lower thermosphere is presented. The instrument consists of a monolithic spatial heterodyne spectrometer (SHS), which is able to resolve the rotational structure of the R-branch of that band. The relative intensities of the emission lines follow a Boltzmann distribution and the ratio of the lines can be used to derive the kinetic temperature. The SHS operates at a Littrow wavelength of 761.8 nm and heterodynes a wavelength regime between 761.9 nm and 765.3 nm with a resolving power of about 8000 considering apodization effects. The size of the SHS is 38 × 38 × 27 mm3 and its acceptance angle is ±5°. It has an etendue of 0.014 cm2 sr. Complemented by a front optics with a solid angle of 0.65° and a detector optics, the entire optical system fits into a volume of about 1.5 liters. This allows to fly this instrument on a 3 or 6 unit CubeSat. The vertical field of view of the instrument is about 60 km at the Earth's limb if operated in a typical low Earth orbit. Integration times to obtain an entire altitude profile of nighttime temperatures are in the order of one minute for a vertical resolution of 1.5 km and a random noise level of 1.5 K. Daytime integration times are one order of magnitude shorter. This work presents the design parameters of the optics and a radiometric assessment of the instrument. Furthermore it gives an overview of the required characterization and calibration steps. This includes the characterization of image distortions in the different parts of the optics, flat fielding and the spectral power estimation.
Tracing winter temperatures over the last two millennia using a NE Atlantic coastal record
Authors: Polovodova Asteman Irina , Filipsson Helena L. , Nordberg Kjell
Published: January 2018

Abstract. We present 2500 years of reconstructed winter temperatures by using a fjord sediment archive from the NE Atlantic. The study is based on ca. 8-m long sediment core from Gullmar Fjord (Sweden), dated by 210Pb and AMS 14C and analysed for stable oxygen isotopes (δ18O) measured on shallow infaunal benthic foraminiferal species Cassidulina laevigata. The bottom water temperatures (BWTs), calculated by using a palaeotemperature equation of McCorkle et al. (1997), range between 2.7–7.8 °C and are within the annual temperature variability, instrumentally recorded in the deep fjord basin since the 1890s. The record demonstrates a warming during the Roman Warm Period (~ 350 BCE–450 CE), variable bottom water temperatures during the Dark Ages (~ 450–850 CE), positive bottom water temperature anomalies during the Viking Age/Medieval Climate Anomaly (~ 850–1350 CE) and a long-term cooling with distinct multidecadal variability during the Little Ice Age (~ 1350–1850 CE). The fjord BWT record also picks up the contemporary warming of the 20th century, which does not stand out in the 2500-year perspective and is of the same magnitude as the Roman Warm Period and the Medieval Climate Anomaly.
Climate sensitivity and meridional overturning circulation in the late Eocene using GFDL CM2.1
Authors: Hutchinson David K. , de Boer Agatha M. , Coxall Helen K. , Caballero Rodrigo , Nilsson Johan , Baatsen Michiel
Published: January 2018

Abstract. The Eocene–Oligocene Transition (EOT), approximately 34 Ma ago, is an interval of great interest in Earth's climate history, due to the inception of the Antarctic ice sheet and major global cooling at the time. Climate simulations of the transition are needed to help us interpret proxy data, test mechanistic hypotheses for the transition, and determine the climate sensitivity at the time. However, model studies of the EOT thus far typically employ control states designed for a different time period, or ocean resolution on the order of 3 degrees. Here we developed a new higher resolution paleoclimate model configuration based on the GFDL CM2.1 climate model adapted to a late Eocene (38 Ma) paleogeography reconstruction. We employ an ocean resolution of 1 × 1.5 degrees, and an atmosphere resolution of 3 × 3.75 degrees. This represents a significant step forward in resolving the ocean geography, gateways and circulation in a coupled climate model of this period. We simulate the model under 3 different levels of CO2; 400, 800 and 1600 ppm. The model exhibits relatively high sensitivity to CO2 compared with other recent model studies, and thus can capture the expected Eocene high latitude warmth within observed estimates of atmospheric CO2. However, the model does not capture the low meridional temperature gradient seen in proxies. Equatorial sea surface temperatures are too high in the model (30–37 degrees C) compared with observations (max 32 degrees C), though observations are lacking in the warmest regions of the western Pacific. The model exhibits robust bipolar sinking in the North Pacific and Southern Ocean, which persists under all levels of CO2. North Atlantic salinities are too fresh to permit sinking (25–30 psu), due to surface transport from the very fresh Arctic (~ 20 psu), whose salinities approximately agree with Eocene proxy estimates. North Atlantic salinity increases by 1–2 psu when CO2 is halved, and similarly freshens when CO2 is doubled, due to changes in the hydrological cycle.
A weekly, near real-time dataset of the probability of large wildfire
across western US forests and woodlands
Authors: Gray Miranda E. , Zachmann Luke J. , Dickson Brett G.
Published: January 2018

Abstract. There is broad consensus that wildfire activity is likely to increase in western US forests and woodlands over the next century. Therefore, spatial predictions of the potential for large wildfires have immediate and growing relevance to near- and long-term research, planning, and management objectives. Fuels, climate, weather, and the landscape all exert controls on wildfire occurrence and spread, but the dynamics of these controls vary from daily to decadal timescales. Accurate spatial predictions of large wildfires should therefore strive to integrate across these variables and timescales. Here, we describe a high spatial resolution dataset (250-m pixel) of the probability of large wildfire (> 405 ha) across all western US forests and woodlands, from 2005 to the present. The dataset is automatically updated on a weekly basis and in near real-time (i.e., up to the present week) using Google Earth Engine and a "Continuous Integration" pipeline. Each image in the dataset is the output of a machine-learning algorithm, trained on 10 independent, random samples of historic small and large wildfires, and represents the predicted probability of an individual pixel burning in a large fire. This novel workflow is able to integrate the short-term dynamics of fuels and weather into weekly predictions, while also integrating longer-term dynamics of fuels, climate, and the landscape. As a near real-time product, the dataset can provide operational fire managers with immediate, on-the-ground information to closely monitor changing potential for large wildfire occurrence and spread. It can also serve as a foundational dataset for longer-term planning and research, such as strategic targeting of fuels management, fire-smart development at the wildland urban interface, and analysis of trends in wildfire potential over time. Weekly large fire probability GeoTiff products from 2005 through 2017 are archived on Figshare online digital repository with the DOI 10.6084/m9.figshare.5765967 (available at https://doi.org/10.6084/m9.figshare.5765967.v1). Near real-time weekly GeoTiff products and the entire dataset from 2005 on are also continuously uploaded to a Google Cloud Storage bucket at https://console.cloud.google.com/storage/wffr-preds/V1, and also available free of charge with a Google account. Near real-time products and the long-term archive are also available to registered Google Earth Engine (GEE) users as public GEE assets, and can be accessed with the image collection ID "users/mgray/wffr-preds" within GEE.
Monthly-averaged maps of surface BRDF parameters in ten spectral
bands for land and water masses
Authors: Blanc Philippe , Gschwind Benoit , Ménard Lionel , Wald Lucien
Published: January 2018

Abstract. The construction of worldwide maps of surface bidirectional reflectance distribution function (BRDF) parameters is presented. The original data stems from the National Aeronautics and Space Administration (NASA) of the USA which is making available maps of BRDF parameters that are derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. The first parameter fiso describes the isotropic part of the BRDF while the two others fvol and fgeo describe the anisotropic part and are linked to the viewing and illuminating geometry. The original data has been averaged for each calendar month for the period 2004–2011 and a spatial completion of data was performed, especially in water-covered areas. The resulting complete maps are available in ten spectral bands: [459–479] nm, [545–565] nm, [620–670] nm, [400–700] nm, [841–876] nm, [1230–1250] nm, [1628–1652] nm, [2105–2155] nm, [250–5000] nm, [700–5000] nm, [250–5000] nm. The maps form a Global Earth Observation System of Systems (GEOSS) Data Collection of Open Resources for Everyone (Data-CORE) supporting the GEOSS Data Sharing Principles. They are referenced by the doi:10.23646/85d2cd5f-ccaa-482e-a4c9-b6e0c59d966c and available in NetCDF format under the Creative Commons license CC-BY.
Atmospheric River Tracking Method Intercomparison Project
(ARTMIP): Project Goals and Experimental Design
Authors: Shields Christine A. , Rutz Jonathan J. , Leung Lai-Yung , Ralph F. Martin , Wehner Michael , Kawzenuk Brian , Lora Juan M. , McClenny Elizabeth , Osborne Tashiana , Payne Ashley E. , Ullrich Paul , Gershunov Alexander , Goldenson Naomi , Guan Bin , Qian Yun , Ramos Alexandre M. , Sarangi Chandan , Sellars Scott , Gorodetskaya Irina , Kashinath Karthik , Kurlin Vitaliy , Mahoney Kelly , Muszynski Grzegorz , Pierce Roger , Subramanian Aneesh C. , Tome Ricardo , Waliser Duane , Walton Daniel , Wick Gary , Wilson Anna , Lavers David ,   Prabhat, Collow Allison , Krishnan Harinarayan , Magnusdottir Gudrun , Nguyen Phu
Published: January 2018

Abstract. The Atmospheric River Tracking Method Intercomparison Project (ARTMIP) is an international collaborative effort to understand and quantify the uncertainties in atmospheric river (AR) science based on detection algorithm alone. Currently, there are many AR identification and tracking algorithms in the literature with a wide range of techniques and conclusions. ARTMIP strives to provide the community with information on different methodologies and provide guidance on the most appropriate algorithm for a given science question or region of interest. All ARTMIP participants will implement their detection algorithms on a specified common dataset for a defined period of time. The project is divided into two phases: Tier 1 will utilize the MERRA-2 reanalysis from January 1980 to June of 2017 and will be used as a baseline for all subsequent comparisons. Participation in Tier 1 is required. Tier 2 will be optional and include sensitivity studies designed around specific science questions, such as reanalysis uncertainty and climate change. High resolution reanalysis and/or model output will be used wherever possible. Proposed metrics include AR frequency, duration, intensity, and precipitation attributable to ARs. Here we present the ARTMIP experimental design, timeline, project requirements, and a brief description of the variety of methodologies in the current literature. We also present results from our 1-month proof of concept trial run designed to illustrate the utility and feasibility of the ARTMIP project.
Technical note: GUARD – An automated fluid sampler preventing sample alteration by contamination, evaporation and gas exchange, suitable for remote areas and harsh conditions
Authors: Hartmann Arno , Luetscher Marc , Wachter Ralf , Holz Philipp , Eiche Elisabeth , Neumann Thomas
Published: January 2018

Abstract. Automated water sampling devices adapted to field operation have proven highly useful for environmental research as well as in the public and private sector, where natural or artificial waters need to be tested regularly for compliance with environmental and health regulations. Such autosamplers are already available on the market in slightly differing versions, but none of these devices are capable of sealing the collected samples to prevent sample alteration by contamination, evaporation or gas exchange. In many sampling cases, however, this feature is essential, for instance for studying the hydrological cycle based on isotopes in rainwater, or for monitoring waters contaminated with toxic gases or other volatile compounds detrimental to biota and human health. Therefore, we have developed a new mobile autosampler, which injects water samples directly into airtight vials, thus preventing any sample alteration. Further advantages include low production costs, compact dimensions and low weight allowing for easy transport, a wide range of selectable sampling intervals as well as a low power consumption, which make it suitable for long-term applications even in remote areas and harsh (outdoor) conditions due to its heavy-duty water-proof casing. In this paper, we demonstrate (1) the sampler's mechanical functioning, (2) the long-term stability of the collected samples with regard to evaporation and gas exchange and (3) the potential of our device in a wide variety of applications drawing on laboratory and field experiments in different karst caves, which represent one of the most challenging sampling environments.
Critical scales to explain urban hydrological response
Authors: Cristiano Elena , ten Veldhuis Marie-Claire , Gaitan Santiago , Ochoa Rodriguez Susana , van de Giesen Nick
Published: January 2018

Abstract. Rainfall variability in space and time, in relation to catchment characteristics and model complexity, plays an important role in explaining the sensitivity of hydrological response in urban areas. In this work we present a new approach to classify rainfall variability in space and time and we use this classification to investigate rainfall aggregation effects on urban hydrological response. Nine rainfall events, measured with a Dual polarimetric X-Band radar at the CAESAR Site (Cabauw Experimental Site for Atmospheric Research, NL), were aggregated in time and space in order to obtain different resolution combinations. The aim of this work was to investigate the influence that rainfall and catchment scales have on hydrological response in urban areas. Three dimensionless scaling factors were introduced to investigate the interactions between rainfall and catchment scale and rainfall input resolution in relation to the performance of the model. Results showed that (1) rainfall classification based on cluster identification well represents the storm core, (2) aggregation effects are stronger for rainfall than flow, (3) model complexity does not have a strong influence compared to catchment and rainfall scales for this study case, (4) scaling factors allow to select the adequate rainfall resolution to obtain a given level of accuracy in the calculation of hydrological response.
Does objective cluster analysis serve as a useful precursor to seasonal precipitation prediction at local scale? Application to western Ethiopia
Authors: Zhang Ying , Moges Semu , Block Paul
Published: January 2018

Abstract. Prediction of seasonal precipitation can provide actionable information to guide management of various sectoral activities. For instance, it is often translated into hydrological forecasts for better water resources management. However, many studies assume homogeneity in precipitation across an entire study region, which may prove ineffective for operational and local-level decisions, particularly for locations with high spatial variability. This study proposes advancing local-level seasonal precipitation predictions by first conditioning on regional-level predictions, as defined through objective cluster analysis, for western Ethiopia. To our knowledge, this is the first study predicting seasonal precipitation at high resolution in this region, where lives and livelihoods are vulnerable to precipitation variability given the high reliance on rain-fed agriculture and limited water resources infrastructure. The combination of objective cluster analysis, spatially high-resolution prediction of seasonal precipitation, and a modeling structure spanning statistical and dynamical approaches makes clear advances in prediction skill and resolution, as compared with previous studies. The statistical model improves versus the non-clustered case or dynamical models for a number of specific clusters in northwestern Ethiopia, with clusters having regional average correlation and ranked probability skill score (RPSS) values of up to 0.5 and 33 %, respectively. The general skill (after bias correction) of the two best-performing dynamical models over the entire study region is superior to that of the statistical models, although the dynamical models issue predictions at a lower resolution and the raw predictions require bias correction to guarantee comparable skills.
Quaternary radiolarian biostratigraphy in the subarctic northeastern Pacific (IODP Expedition 341 Site U1417) and synchroneity of bioevents across the North Pacific
Authors: Matsuzaki Kenji M. , Suzuki Noritoshi
Published: January 2018

Abstract. Expedition 341 of the Integrated Ocean Drilling Program (IODP) retrieved sediment cores spanning the time interval between the Pleistocene and Miocene from the southern Gulf of Alaska. Onboard Pleistocene radiolarian biostratigraphy is hereby refined by increasing the sampling resolution. The 178 core samples from the upper 190 m CCSF-B (Composite Core Depth Scale F-B) of Site U1417 contained faunal elements similar to the northwestern Pacific; for example, the three biozones in the northwestern Pacific (i.e., Eucyrtidium matuyamai, Stylatractus universus and Botryostrobus aquilonaris) were also recognized in the Gulf of Alaska, spanning 1.80–1.13 Ma, 1.13–0.45 Ma, and the last 0.45 Myr, respectively. Based on the age model that we used in this study and the shipboard paleomagnetic reversal events, the first occurrences (FOs) of Amphimelissa setosa and Schizodiscus japonicus in the northeastern Pacific were preliminarily determined to be 1.48 and 1.30 Ma, respectively. The last occurrence (LO) of Eucyrtidium matuyamai and the FO of Lychnocanoma sakaii, both well-established bioevents in the northwestern Pacific, were dated at 0.80 and 1.13 Ma, respectively. The LO of E. matuyamai is a synchronous event at 1.05 ± 0.1 Ma in the North Pacific, while the FOs of A. setosa and S. japonicus at 1.48 and 1.30 Ma, respectively, are significantly older than what has been found elsewhere.
Stratigraphic calibration of Oligocene–Miocene organic-walled dinoflagellate cysts from offshore Wilkes Land, East Antarctica, and a zonation proposal
Authors: Bijl Peter K. , Houben Alexander J. P. , Bruls Anja , Pross Jörg , Sangiorgi Francesca
Published: January 2018

Abstract. There is growing interest in the scientific community in reconstructing the paleoceanography of the Southern Ocean during the Oligocene–Miocene because these time intervals experienced atmospheric CO2 concentrations with relevance to our future. However, it has remained notoriously difficult to put the sedimentary archives used in these efforts into a temporal framework. This is at least partially due to the fact that the bio-events recorded in organic-walled dinoflagellate cysts (dinocysts), which often represent the only microfossil group preserved, have not yet been calibrated to the international timescale. Here we present dinocyst ranges from Oligocene–Miocene sediments drilled offshore the Wilkes Land continental margin, East Antarctica (Integrated Ocean Drilling Program (IODP) Hole U1356A). In addition, we apply statistical means to test a priori assumptions about whether the recorded taxa were deposited in situ or were reworked from older strata. Moreover, we describe two new dinocyst species, Selenopemphix brinkhuisii sp. nov. and Lejeunecysta adeliensis sp. nov., which are identified as important markers for regional stratigraphic analysis. Finally, we calibrate all identified dinocyst events to the international timescale using independent age control from calcareous nanoplankton and magnetostratigraphy from IODP Hole U1356A, and we propose a provisional dinoflagellate cyst zonation scheme for the Oligocene–Miocene of the Southern Ocean.
New species of Cenozoic benthic foraminifera from the former British Petroleum micropalaeontology collection
Authors: Fox Lyndsey R. , Stukins Stephen , Hill Tom , Bailey Haydon
Published: January 2018

Abstract. This paper describes four new Cenozoic, deep-water benthic foraminifera from the reference collections at the Natural History Museum in London. The focus is on selected calcareous taxa that are of stratigraphical and/or palaeoecological significance for academic and industrial-related activities. Alabamina heyae (urn:lsid:zoobank.org:act:1E8A66E9-1F4C-4B61-BA97-6E0ECCD0173E), Nonion cepa (urn:lsid:zoobank.org:act:9F36350A-1E49-4D69-B2CC-C83F343E2952), Uvigerina kingi (urn:lsid:zoobank.org:act:C36C89C2-2E65-4FF6-9368-C169B4591995) and Lenticulina stewarti (urn:lsid:zoobank.org:act:485AE871-CECA-44E8-ABD1-BAE2961FFD59) are described with new illustrations. Their biostratigraphic and palaeoecological significance is briefly discussed.
Granular metal–carbon nanocomposites as piezoresistive sensor films – Part 1: Experimental results and morphology
Authors: Schultes Günter , Schmid-Engel Hanna , Schwebke Silvan , Werner Ulf
Published: January 2018

Abstract. We have produced granular films based on carbon and different transition metals by means of plasma deposition processes. Some of the films possess an increased strain sensitivity compared to metallic films. They respond to strain almost linearly with gauge factors of up to 30 if strained longitudinally, while in the transverse direction about half of the effect is still measured. In addition, the film's thermal coefficient of resistance is adjustable by the metal concentration. The influence of metal concentration was investigated for the elements Ni, Pd, Fe, Pt, W, and Cr, while the elements Co, Au, Ag, Al, Ti, and Cu were studied briefly. Only Ni and Pd have a pronounced strain sensitivity at 55 ± 5 at. % (atomic percent) of metal, among which Ni–C is far more stable. Two phases are identified by transmission electron microscopy and X-ray diffraction: metal-containing nanocolumns densely packed in a surrounding carbon phase. We differentiate three groups of metals, due to their respective affinity to carbon. It turns out that only nickel has the capability to bond and form a stable and closed encapsulation of GLC around each nanoparticle. In this structure, the electron transport is in part accomplished by tunneling processes across the basal planes of the graphitic encapsulation. Hence, we hold these tunneling processes responsible for the increased gauge factors of Ni–C composites. The other elements are unable to form graphitic encapsulations and thus do not exhibit elevated gauge factors.
A novel non-contact measuring system for the thread profile of a ball screw
Authors: Zhao Leilei , Feng Hutian , Rong Qianfeng
Published: January 2018

Abstract. In order to meet the demand of high position accuracy, many methods have been developed for measuring the thread profile features of ball screws. However, most of these efforts are limited to measuring a small number of ball screw features and therefore less efficient. In this study, an automatic, non-contact measuring system for the thread profile of a ball screw was developed. It is capable of measuring most common features of the ball screw thread profile and can measure ball screws of different sizes and lengths. The main part of the system is the light curtain which has a high-resolution line-scan CCD camera to measure the projected outer contour of the target. Data points from the thread profile of a ball screw were collected by the measuring system and data pre-processing was performed. Then, the proposed method was used to calculate the most important geometric parameters and errors of the thread profile. The accuracy of the measuring system was verified by testing and evaluating four sets of ball screws from different manufacturers.
Field-based landslide susceptibility assessment in a data-scarce environment: the populated areas of the Rwenzori Mountains
Authors: Jacobs Liesbet , Dewitte Olivier , Poesen Jean , Sekajugo John , Nobile Adriano , Rossi Mauro , Thiery Wim , Kervyn Matthieu
Published: January 2018

Abstract. The inhabited zone of the Ugandan Rwenzori Mountains is affected by landslides, frequently causing loss of life, damage to infrastructure and loss of livelihood. This area of ca. 1230 km2 is characterized by contrasting geomorphologic, climatic and lithological patterns, resulting in different landslide types. In this study, the spatial pattern of landslide susceptibility is investigated based on an extensive field inventory constructed for five representative areas within the region (153 km2) and containing over 450 landslides. To achieve a reliable susceptibility assessment, the effects of (1) using different topographic data sources and spatial resolutions and (2) changing the scale of assessment by comparing local and regional susceptibility models on the susceptibility model performances are investigated using a pixel-based logistic regression approach. Topographic data are extracted from different digital elevation models (DEMs) based on radar interferometry (SRTM and TanDEM-X) and optical stereophotogrammetry (ASTER DEM). Susceptibility models using the radar-based DEMs tend to outperform the ones using the ASTER DEM. The model spatial resolution is varied between 10, 20, 30 and 90 m. The optimal resolution depends on the location of the investigated area within the region but the lowest model resolution (90 m) rarely yields the best model performances while the highest model resolution (10 m) never results in significant increases in performance compared to the 20 m resolution. Models built for the local case studies generally have similar or better performances than the regional model and better reflect site-specific controlling factors. At the regional level the effect of distinguishing landslide types between shallow and deep-seated landslides is investigated. The separation of landslide types allows us to improve model performances for the prediction of deep-seated landslides and to better understand factors influencing the occurrence of shallow landslides such as tangent curvature and total rainfall. Finally, the landslide susceptibility assessment is overlaid with a population density map in order to identify potential landslide risk hotspots, which could direct research and policy action towards reduced landslide risk in this under-researched, landslide-prone region.
From Tsunami Risk Assessment to Disaster Risk Reduction. The case of Oman
Authors: Aguirre Ayerbe Ignacio , Martínez Sánchez Jara , Aniel-Quiroga Íñigo , González Riancho Pino , Merino María , Al-Yahyai Sultan , González Mauricio , Medina Raúl
Published: January 2018

Abstract. Oman is located in an area of high seismicity, facing the Makran Subduction Zone, which is the major source of earthquakes in the eastern border of the Arabian plate. These earthquakes, as evidenced by several past events, may trigger a tsunami event. The aim of this work is to minimize the consequences that tsunami events may cause in coastal communities by integrating tsunami risk assessment and risk reduction measures as part of the risk-management preparedness strategy. An integrated risk assessment approach and the analysis of site-specific conditions permitted to propose target-oriented risk reduction measures. The process included a participatory approach, involving a panel of local and international experts. One of the main concerns of this work was to obtain a really useful outcome for the actual improvement of tsunami risk management in Oman. This goal was achieved through the development of comprehensive and functional management tools such as the Tsunami Hazard, Vulnerability and Risk Atlas and the Risk Reduction Measures Handbook, which will help to design and plan a roadmap towards risk reduction.
Deformation mechanisms and evolution of the microstructure of gouge in the Main Fault in Opalinus Clay in the Mont Terri rock laboratory (CH)
Authors: Laurich Ben , Urai Janos L. , Vollmer Christian , Nussbaum Christophe
Published: January 2018

Abstract. We studied gouge from an upper-crustal, low-offset reverse fault in slightly overconsolidated claystone in the Mont Terri rock laboratory (Switzerland). The laboratory is designed to evaluate the suitability of the Opalinus Clay formation (OPA) to host a repository for radioactive waste. The gouge occurs in thin bands and lenses in the fault zone; it is darker in color and less fissile than the surrounding rock. It shows a matrix-based, P-foliated microfabric bordered and truncated by micrometer-thin shear zones consisting of aligned clay grains, as shown with broad-ion-beam scanning electron microscopy (BIB-SEM) and optical microscopy. Selected area electron diffraction based on transmission electron microscopy (TEM) shows evidence for randomly oriented nanometer-sized clay particles in the gouge matrix, surrounding larger elongated phyllosilicates with a strict P foliation. For the first time for the OPA, we report the occurrence of amorphous SiO2 grains within the gouge. Gouge has lower SEM-visible porosity and almost no calcite grains compared to the undeformed OPA. We present two hypotheses to explain the origin of gouge in the Main Fault: (i) authigenic generation consisting of fluid-mediated removal of calcite from the deforming OPA during shearing and (ii) clay smear consisting of mechanical smearing of calcite-poor (yet to be identified) source layers into the fault zone. Based on our data we prefer the first or a combination of both, but more work is needed to resolve this. Microstructures indicate a range of deformation mechanisms including solution–precipitation processes and a gouge that is weaker than the OPA because of the lower fraction of hard grains. For gouge, we infer a more rate-dependent frictional rheology than suggested from laboratory experiments on the undeformed OPA.
Where is the 1-million-year-old ice at Dome A?
Authors: Zhao Liyun , Moore John C. , Sun Bo , Tang Xueyuan , Guo Xiaoran
Published: January 2018

Abstract. Ice fabric influences the rheology of ice, and hence the age/depth profile at ice core drilling sites. We use the depth varying anisotropic fabric suggested by the recent polarimetric measurements around Dome A along with prescribed fabrics ranging from isotropic through girdle to single maximum in a three-dimensional, thermo-mechanically coupled full-Stokes model of a 70 × 70 km2 domain around Kunlun station. This model allows to simulate the near basal ice temperature and age, and ice flow around the location of the Chinese deep ice coring site. Ice fabrics and geothermal heat flux strongly affect the vertical advection and basal temperature which in consequence controls the age profile. Constraining modeled age-depth profiles with dated radar isochrones to 2/3 ice depth, the surface vertical velocity, and also the spatial variability of a radar isochrones dated to 153.3 kyr BP, limits the age of the deep ice at Kunlun to 649–831 kyr, a much smaller range than inferred previously. The simple interpretation of the polarmetric radar fabric data that we use produces best fits with a geothermal heat flux of 55 mWm−2. A heat flux of 50 mWm−2 is too low to fit the deeper radar layers, and a heat flux of 60 mWm−2 leads to unrealistic surface velocities. The modeled basal temperature at Kunlun reaches the pressure melting point with a basal melting rate of 2.2–2.7 mm yr−1. Using the spatial distribution of basal temperatures and the best fit fabric suggests that within 400 m of Kunlun station, 1 million-year old ice may be found 200 m above the bed, and there are large regions where even older ice is well above the bedrock within 1–2 km of the Kunlun station.