bluuebunny/crossref_metadata_2025 huggingface dataset:
One-sample two-smear versus two-sample two-smear approach for the diagnosis of pulmonary tuberculosis
Authors: Chandra T. Jaya
Published: February 2020

BACKGROUND: To evaluate the efficacy of one-sputum sample two-smear approach for the diagnosis of pulmonary tuberculosis (PT).

MATERIALS AND METHODS: Data from January 2012 to December 2015 were analyzed to find (1) number of smear positives (SPs) by spot (S) sample with one and two smears; (2) number of SPs by morning (M) sample with one and two smears; and (iii) number of SPs by two samples with two smears, that is, same-day (SS2) and spot morning (SM) approaches. The Chi-square test was used to evaluate the statistical difference in SP cases.

RESULTS: With one-sample two-smear approach, the smear positivity (SPT) was 87% and 87.5%, for S and M samples, respectively, for Ziehl–Neelsen (ZN) staining; whereas, SPT was 96% and 97%, respectively, for S and M samples, for fluorescent staining (FS) technique. With two-sample two-smear approach, for ZN staining, SPT was 89% each and for FS technique, SPT was 97% and 99%, respectively, for SS2 and SM approaches. The difference was not statistically significant (P > 0.05) between one- and two-sample approaches in the staining techniques.

CONCLUSION: Significant number of SP cases are identified by S sample two-smear approach. Thus, the World Health Organization/Revised National Tuberculosis Control Programme can initiate S sample two-smear approach for the diagnosis of PT.
Phenotypic and genotypic characterization of carbapenem resistance mechanisms in Klebsiella pneumoniae from blood culture specimens: A study from North India
Authors: Gupta Varsha , Garg Ritu , Kumaraswamy Karthikeyan , Datta Priya , Mohi Gursimran Kaur , Chander Jagdish
Published: February 2020

BACKGROUND: Emergence of carbapenem resistance among Enterobacteriaceae in different geographical regions is of great concern as these bacteria are easily transmissible among patients. Carbapenem-resistance in Enterobacteriaceae is due to production of carbapenemases of various classes and hyper production of the ESBLs (Extended spectrum beta lactamases) and Amp C beta lactamases with reduced cell wall permeability mechanisms. Phenotypic detection and differentiation is important for proper infection control and appropriate patient management. This study was done to know the prescence of various beta lactamases and carbapenemases with other mechanisms of resistance in Klebsiella pneumoniae isolates.

MATERIALS AND METHODS: 50 non-duplicate carbapenem resistant isolates of Klebsiella pneumoniae from blood culture specimens were included and various mechanisms of resistance were studied based on phenotypic and genotypic methods.

RESULTS: Out of 50 isolates, 39 (78%) of K.pneumoniae isolates were Extended Spectrum Beta Lactamase (ESBL) producers based on CLSI guidelines. All 50 showed positive Modified Hodge Test (MHT ) and 32 showed Metallo Beta Lactamase (MBL) by Combined Disc Test (CDT). Four isolates showed AmpC production with porin loss . None of the isolates showed Class A KPC production by CDT . In our study all the 10 isolates evaluated by genotypic technique produced CTX-M group 1 enzyme by multiplex PCR. Seven out of 10 strains which showed positive MBL results were positive for NDM .

CONCLUSIONS: Carbapenems are often considered last resort antibiotics in the treatment of infections due to multidrug-resistant organisms. It is therefore mandatory to maintain the clinical efficacy of carbapenems by early detection of various enzymes . For routine clinical laboratories both phenotypic and genotypic tests need to be followed to detect various mechanisms of carbapenem resistance and this is of epidemiological relevance also.
Complement deficiency in pediatric-onset systemic lupus erythematosus
Authors: Afzali Parisa , Isaeian Anna , Sadeghi Peyman , Moazzami Bobak , Parvaneh Nima , Robatjazi Masoumeh , Ziaee Vahid
Published: February 2020

BACKGROUND: Pediatric-onset systemic lupus erythematosus (pSLE) accounts for about 10%-20% of all patients with SLE. Deficiencies in early complement components of the classical pathway are the strong genetic risk factor for the development of SLE. In this study, clinical and laboratory manifestations of both complement-deficient and normal complement pSLE patients were compared.

MATERIALS AND METHODS: To investigate clinical and immunological manifestations of pSLE in Iran, 36 consecutive pSLE patients (onset before 18 years) who were followed up over a period of 2 years, were studied. Complement C1q and C2 levels were measured using radial immunodifusion assay and complement C3 and C4 levels were measured using nephelometry. Medical records were retrospectively evaluated from patient database of Children Medical Center Hospital. Data were assessed through descriptive analysis (confidence interval = 95%), paired t-test, and Pearson correlation test.

RESULTS: Twenty-one patients (58%) had at least one component of complement deficiency. Ten patients (27%) had low C1q level, 11 patients (30.5%) had low C2, nine patients (25%) had low C3, and four patients (11%) had low C4 level. Serum level of complement in pSLE was significantly lower than the control group, except C4 (P = 0.005). The low C1q patients had an earlier age of onset of disease (P < 0.0001). The cutaneous manifestations were more frequent and much more severe in pSLE with low complement (100% vs. 73%). The frequency of renal and musculoskeletal symptoms was equal, but renal morbidity was more common in pSLE with low complement. Positivity for anti-ds-DNA was less common in pSLE with low complement (71% vs. 86%).

CONCLUSION: In pSLE patients with early disease onset and more aggressive SLE manifestations and negative anti-ds-DNA test, complement deficiency should be considered.
Virulence determinant and extended spectrum beta-lactamase production in Klebsiella pneumoniae isolated from a tertiary care hospital, South India
Authors: Kotekani Lathamani , Kotigadde Subbannayya
Published: February 2020

BACKGROUND: Klebsiella pneumoniae on these days show greater resistance towards newer generation cephalosporin. The present study made an effort to show the relevance between ESBL producing K. pneumoniae and virulence determinant in respect to serum resistance and K1, K2 antigens at a tertiary care hospital in South India.

MATERIAL AND METHODS: A total of 520 consecutive, non-duplicate isolates of K. pneumoniae were recovered from various clinical specimens such as Urine (n = 360), sputum (n = 107), pus (n = 25), blood (n = 6) and other miscellaneous specimens (n=22) obtained from both out patients and in patients between June 2012 to July 2016 were included in the study.

RESULTS: Polymerase Chain Reaction to detect bla genes in 62 isolates phenotypically identified as ESBL producers were successful in 58 (93.54%) isolates. Of the 13 ESBL producing hypermucoviscous Klebsiella pneumoniae (hvKP) strains, 6 of them were showing the amplicons for gene's coding for K1 antigens.

CONCLUSION: The study provides further authentication of the global sporadic of bla CTX-M and the relevance between K antigens and serum resistance with ESBL production in our place. As there is no much study available, it also highlights the need for further study of their epidemiological surveillance.
Is the platelet-to-lymphocyte ratio a new prognostic marker in multiple myeloma?
Authors: Solmaz Serife , Uzun Ozcan , Acar Celal , Sevindik Omur Gokmen , Piskin Ozden , Ozsan Hayri Guner , Demirkan Fatih , Undar Bulent , Alacacioglu Ahmet , Ozcan Mehmet Ali , Alacacioglu Inci
Published: February 2020

BACKGROUND: Recent reports showed neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR), as a predictor of progression-free survival (PFS) and overall survival (OS) in various malignancies.

MATERIALS AND METHODS: We retrospectively examined the PLR, NLR, and MLR in a cohort of 186 newly diagnosed multiple myeloma (MM) patients. This study investigated the prognostic relevance of NLR, PLR, and MLR in MM patients. NLR, PLR, and MLR were calculated from whole blood counts before therapy. The Kaplan–Meier curves and multivariate Cox models were used for the evaluation of survival.

RESULTS: Applying cutoff of 1.9 (NLR), 120.00 (PLR), and 0.27 (MLR), decreased PLR showed a negative impact on the outcome. Decreased PLR is an independent predictor for PFS and OS. There were no significant differences in median survival between the high and low NLR (P = 0.80) and MLR (P = 0.87) groups.

CONCLUSIONS: In this study, thrombocytopenia and low PLR are associated with poor survival in MM patients does this P value apply to thrombocytopenia or low PLR and may serve as the cost-effective prognostic biomarker.
Evaluation of 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyl tetrazolium bromide method for assessing biofilm formation in vitro by Trichosporon spp.
Authors: Premamalini Thayanidhi , Anitha Subramanian , Mohanapriya Kanniappan , Kindo Anupma Jyoti
Published: February 2020

BACKGROUND: Invasive infections due to Trichosporon spp. have increased recently and are frequently associated with indwelling medical devices. Such infections which are associated with biofilm formation do not respond to the routinely used antifungal agents and are often persistent, associated with high mortality rate. Various methods have been described by researchers to evaluate and quantify the biofilm formation.

AIM: This study was conducted to compare two methods of biofilm production by Trichosporon sp, i.e., test tube method with crystal violet (CV) staining and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay.

MATERIALS AND METHODS: Seventy-two clinical isolates of Trichosporon spp. collected from various sources were considered for the study. The identity of all the isolates was genotypically confirmed by Trichosporon-specific polymerase chain reaction (PCR). The isolates were further speciated phenotypically using biochemical profile and growth characteristics which identified the isolates as Trichosporon asahii (64/72), Trichosporon asteroides (5/72), Trichosporon cutaneum (2/72), and Trichosporon mucoides (1/72). Biofilm production was then evaluated and compared by test tube-CV method and MTT assay.

RESULTS: All the Trichosporon isolates produced biofilm by MTT assay, whereas only 42 (53.6%) of the isolates were detected to be biofilm producers by CV method. Furthermore, MTT assay could differentiate better between weak and moderate biofilm producers as compared to CV method.

CONCLUSION: Hence, MTT assay is a reliable method for quantification of biofilm produced by Trichosporon spp. using 96-well microtiter plate.
Characterization and antimicrobial susceptibility of coagulase-negative staphylococci isolated from clinical samples
Authors: Bora Prapti , Datta Priya , Gupta Varsha , Singhal Lipika , Chander Jagdish
Published: February 2020

PURPOSE: This study has been done to speciate coagulase-negative staphylococci (CoNS) and also study their antibiotic susceptibility pattern isolated from clinical samples.

MATERIALS AND METHODS: A total of 120 consecutive CoNS were isolated from various clinical samples such as blood, pus, wound swab, drain fluid, tracheal aspirate, peritoneal fluid, and pleural fluid over a period of 6 months. CoNS were identified by characteristic growth on media such as Blood agar and MacConkey agar. Speciation and identification were done by a range of biochemical testing such as PYR broth hydrolysis, novobiocin resistance, polymyxin B sensitivity, and then by matrix-assisted laser desorption ionization-time of flight. Antibiotic susceptibility of the isolates was done by Kirby-Bauer disk diffusion method as per CLSI 2017 guidelines.

RESULTS: Among the 120 isolates, the most common species was Staphylococcus epidermidis (56.67%) followed by Staphylococcus haemolyticus (21.67%), Staphylococcus lugdunensis (11.67%), Staphylococcus caprae (5%), Staphylococcus cohnii (3.33%), and finally Staphylococcus vitulinus (1.67%). Good in vitro susceptibility was noted toward linezolid (100%), vancomycin (100%), teicoplanin (100%), and doxycycline (80.2%). The antibiotics to which resistance was seen were penicillin (96.5%), ciprofloxacin (57.1%), and oxacillin (45.5%). MR CoNS in our study ranged from 50% to 68.67%.

CONCLUSION: Antibiotic resistance in CoNS is increasing toward penicillin, ciprofloxacin, and oxacillin as found in our study. The antibiotics such as vancomycin, teicoplanin, linezolid, and doxycycline which showed good in vitro susceptibility, therefore, should be kept as reserve drugs and used judiciously.
Gallstone disease and quantitative analysis of independent biochemical parameters: Study in a tertiary care hospital of India
Authors: Dhamnetiya Deepak , Goel Manish Kumar , Dhiman BalRaj , Pathania Om Prakash
Published: February 2020

INTRODUCTION: Gallstone disease (GSD) represents a significant burden for health-care systems worldwide and is one of the most common disorders among patients presenting to emergency rooms with abdominal discomfort. This study was aimed to know the association of biochemical parameters and development of GSD.

MATERIALS AND METHODS: We conducted a case–control study from January 2013 to December 2013 among patients attending outpatient department of general surgery at a tertiary care hospital of Delhi, North India; we recruited 120 cases and the same number of controls in the study. Data collection for both cases and controls was done on a self-designed pretested interview schedule and all the patients were investigated for relevant biochemical parameters. Logistic regression was used for univariate and multivariate analyses to find out different correlates and analyze the independent effects of these correlates on GSD.

RESULTS: We have included 120 cases and the same number of age- and sex-matched controls in the study and final analysis. Almost 70% of the cases were females and 30% were males. In multivariate logistic regression, we have found maximum significant association with serum total cholesterol (odds ratio [OR]: 1.013, confidence interval [CI]: 1.003–1.024, P = 0.041) followed by low-density lipoprotein (LDL) cholesterol (OR: 1.017, CI: 1.001–1.034, P = 0.04) and triglycerides (OR: 1.009, CI: 1.001–1.018, P = 0.049). Fasting blood sugar (P = 0.18), high-density lipoprotein cholesterol (P = 0.07), aspartate transaminase (P = 0.21), alanine transaminase (P = 0.29), and total bilirubin (P = 0.13) were not found to be independently associated with GSD.

Conclusions: Biochemical parameters such as plasma total cholesterol, triglycerides, and LDL cholesterol level were independently associated with GSD.
The variability in Gaseous Elemental Mercury at Villum Research Station, Station Nord in North Greenland from 1999 to 2017
Authors: Skov Henrik , Hjorth Jens , Nordstrøm Claus , Jensen Bjarne , Christoffersen Christel , Bech Poulsen Maria , Baldtzer Liisberg Jesper , Beddows David , Dall'Osto Manuel , Christensen Jesper
Published: February 2020

Abstract. Mercury is ubiquitous in the atmosphere and atmospheric transport is an important source for this element in the Arctic. Measurements of gaseous elemental mercury (GEM) have been carried out at the Villum Research Station (Villum) at Station Nord, situated in north Greenland. The measurements cover the period 1999–2017 with a gap in the data for the period 2003–2008 (for a total of 11 years). The measurements were compared with model results from the Danish Eulerian Hemispheric Model (DEHM) model that describes the contribution from direct anthropogenic transport, marine emission and general background concentration. The percentage of time spent over different surfaces was calculated by back-trajectory analysis and the reaction kinetics was determined by comparison with ozone. The GEM measurements were analysed for trends, both seasonal and annually. The only significant trend found was a negative one for the winter months. Comparison of the measurements to simulations using the Danish Eulerian Hemispheric Model (DEHM) indicated that direct transport of anthropogenic emissions of mercury accounts for between 14 and 17 % of the measured mercury. Analysis of the kinetics of the observed Atmospheric Mercury Depletion Events (AMDEs) confirms the results of a previous study at Villum of the competing reactions of GEM and ozone with Br, which suggests a lifetime of GEM on the order of a month. However, a GEM lifetime of 12 months gave the best agreement between model and measurements. The chemical lifetime is shorter and thus the apparent lifetime appears to be the result of deposition followed by reduction and reemission; for this reason the term relaxation time is preferred to lifetime for GEM. The relaxation time for GEM causes a delay between emission reductions and the effect on actual concentrations. No annual trend was found for the measured concentrations of GEM over the measurement period despite emission reductions. This is interesting and together with low direct transport of GEM to Villum, as found by the DEHM model, it shows that the dynamics of GEM is very complex. Therefore in the coming years, intensive measurement networks is highly needed to describe the global distribution of mercury in the environment as the use of models to predict future levels will still be highly uncertain. The situation is increasingly complex due to global change that most likely will change the transport patterns of mercury not only in the atmosphere but also between matrixes.
Opposite Effects of Aerosols on Daytime Urban Heat Island Intensity between Summer and Winter
Authors: Han Wenchao , Li Zhanqing , Wu Fang , Zhang Yuwei , Guo Jianping , Su Tianning , Cribb Maureen , Chen Tianmeng , Wei Jing , Lee Seoung-Soo
Published: February 2020

Abstract. The urban heat island intensity (UHII) is the temperature difference between urban areas and their rural surroundings. It is commonly attributed to changes in the underlying surface structure caused by urbanization. Air pollution caused by aerosol particles can affect the UHII by changing the surface energy balance and atmospheric thermodynamic structure. By analyzing satellite data and ground-based observations collected from 2001 to 2010 at 35 cities in China and using the WRF-Chem model, we found that aerosols have very different effects on daytime UHII in different seasons: reducing the UHII in summer, but increasing the UHII in winter. The seasonal contrast in the spatial distribution of aerosols between the urban centers and the suburbs lead to a spatial discrepancy in aerosol radiative effect (SD-ARE). Additionally, different stability of the planetary boundary layer induced by aerosol is closely associated with a dynamic effect (DE) on the UHII. SD-ARE reduces the amount of radiation reaching the ground and changes the vertical temperature gradient, whereas DE increases the stability of the planetary boundary layer and weakens heat release and exchange between the surface and the PBL. Both effects exist under polluted conditions, but their relative roles are opposite between the two seasons. It is the joint effects of the SD-ARE and the DE that drive the UHII to behave differently in different seasons, which is confirmed by model simulations. In summer, the UHII is mainly affected by the SD-ARE, and the DE is weak, and the opposite is the case in winter. This finding sheds a new light on the impact of the interaction between urbanization-induced surface changes and air pollution on urban climate.
The nitrogen budget of laboratory-simulated western U.S. wildfires during the FIREX 2016 FireLab study
Authors: Roberts James M. , Stockwell Chelsea E. , Yokelson Robert J. , de Gouw Joost , Liu Yong , Selimovic Vanessa , Koss Abigail R. , Sekimoto Kanako , Coggon Matthew M. , Yuan Bin , Zarzana Kyle J. , Brown Steven S. , Santin Cristina , Doerr Stefan H. , Warneke Carsten
Published: February 2020

Abstract. Total reactive nitrogen (Nr, defined as all nitrogen-containing compounds except for N2 and N2O) was measured by catalytic conversion to NO and detection by NO-O3 chemiluminescence together with individual Nr species during a series of laboratory fires of fuels characteristic of Western U.S. wildfires, conducted as part of the FIREX FireLab 2016 study. Data from 75 stack fires were analyzed to examine the systematics of nitrogen emissions. The Nr/total-carbon ratios measured in the emissions were compared with fuel and ash N/C ratios and mass to estimate that a mean (± std. dev.) of 0.68 (± 0.14) of fuel nitrogen was emitted as N2 and N2O. The remaining fraction of Nr was emitted as individual compounds: nitric oxide (NO), nitrogen dioxide (NO2), nitrous acid (HONO), isocyanic acid (HNCO), hydrogen cyanide (HCN), ammonia (NH3), and 44 nitrogen-containing volatile organic compounds (NVOCs). The relative difference between the total reactive nitrogen measurement, Nr, and the sum of measured individual Nr compounds had a mean (± std. dev) of 0.152 (± 0.098). Much of this unaccounted Nr is expected to be particle-bound species, not included in this analysis. A number of key species, e.g. HNCO, HCN and HONO, were confirmed not to correlate only with flaming or only with smoldering combustion when using modified combustion efficiency (MCE = CO2/(CO + CO2)) as a rough indicator. However, the systematic variations of the abundance of these species relative to other nitrogen-containing species were successfully modeled using positive matrix factorization (PMF). Three distinct factors were found for the emissions from combined coniferous fuels, aligning with our understanding of combustion chemistry in different temperature ranges: a combustion factor (Comb-N) (800–1200 °C) with emissions of the inorganic compounds NO, NO2 and HONO, and a minor contribution from organic nitro compounds (R-NO2); a high-temperature pyrolysis factor (HT-N) (500–800 °C) with emissions of HNCO, HCN and nitriles; and a low-temperature pyrolysis factor (LT-N) (
Tomographic retrieval algorithm of OH concentration profiles using Double Spatial Heterodyne Spectrometers
Authors: An Yuan , Ma Jinji , Gao Yibo , Xiong Wei , Wang Xianhua
Published: February 2020

Abstract. The hydroxyl radical (OH) determines the atmospheric self-cleaning capability and is one of the significant oxidants in atmospheric photochemistry reactions. The global OH has been monitored by satellites with the traditional limb mode in the past decades. This observed mode can achieve high-resolution vertical OH data, but cannot obtain the enough horizontal OH data for inverting high-precision OH concentrations because OH has the high reactivity that makes its concentrations extremely low and distributions complicated. The Double Spatial Heterodyne Spectrometers (DSHS) is designed in order to achieve more high-resolution and detailed OH data. This sensor can measure the OH by the three-dimensional limb mode to obtain the comprehensive OH data in the atmosphere. We propose a new tomographic retrieval algorithm here based on the simulated observation data due to the DSHS will work officially on the orbit in the future. We build up an accurate forward model that the main part of it is the SCIATRAN radiative transfer model which is modified according to the radiation transmission theory. We also construct the tomographic retrieval algorithm that the core is a look up table method. A tomographic observed database is built up through the atmospheric model, the spatial information (position of the target area and satellite position), the date parameters, the observation geometries, OH concentrations and simulated observation data. The OH concentrations can be found directly from it. If there are no corresponding query conditions in the tomographic observed database, the cubic spline interpolation is used to obtain the OH concentrations. The tomographic retrieval algorithm can obtain the more accurate OH concentrations even in the lower atmosphere where the OH data is not well and avoids the initial guess values for solving the iteration problems. Our research not only provides a scientific theory support for the construction of DSHS, but also gives a new retrieval algorithm idea for other radicals.
Isotopic evidence for alteration of nitrous oxide emissions and producing pathways' contribution under nitrifying conditions
Authors: Humbert Guillaume , Sébilo Mathieu , Fiat Justine , Lang Longqi , Filali Ahlem , Vaury Véronique , Spérandio Mathieu , Laverman Anniet M.
Published: February 2020

Abstract. Nitrous oxide (N2O) emissions from a nitrifying
biofilm reactor were investigated with N2O isotopocules. The nitrogen
isotopomer site preference of N2O (15N-SP) indicated the
contribution of producing and consuming pathways in response to changes in
oxygenation level (from 0 % to 21 % O2 in the gas mix), temperature
(from 13.5 to 22.3 ∘C) and ammonium concentrations (from 6.2 to
62.1 mg N L−1). Nitrite reduction, either nitrifier denitrification or
heterotrophic denitrification, was the main N2O-producing pathway under
the tested conditions. Difference between oxidative and reductive rates of
nitrite consumption was discussed in relation to NO2-
concentrations and N2O emissions. Hence, nitrite oxidation rates seem
to decrease as compared to ammonium oxidation rates at temperatures above 20 ∘C and under oxygen-depleted atmosphere, increasing N2O
production by the nitrite reduction pathway. Below 20 ∘C, a
difference in temperature sensitivity between hydroxylamine and ammonium
oxidation rates is most likely responsible for an increase in N2O
production via the hydroxylamine oxidation pathway (nitrification). A
negative correlation between the reaction kinetics and the apparent isotope
fractionation was additionally shown from the variations of δ15N and δ18O values of N2O produced from ammonium.
The approach and results obtained here, for a nitrifying biofilm reactor
under variable environmental conditions, should allow for application and
extrapolation of N2O emissions from other systems such as lakes, soils
and sediments.
A new method to quantitatively control oxygen fugacity in externally heated pressure vessel experiments
Authors: Alex Alice , Zajacz Zoltán
Published: February 2020

Abstract. Oxygen fugacity (fO2) is a fundamental variable affecting phase equilibrium in magmas, and in externally heated pressure vessel experiments
it is typically controlled by using redox buffer assemblages. However,
these do not allow fine enough resolution; for example, most arc magmas fall between the fO2 imposed by the neighboring Ni–NiO and Re–ReO2 buffers and so does the transition of S2− to S6+ in magmas. Here we propose a new method to quantitatively impose fO2 in hydrous high-P–T experiments in molybdenum hafnium carbide (MHC) pressure vessels by admixing small amounts of hydrogen into the Ar pressure medium. The thermodynamic calculation procedure used to determine the initial amount of hydrogen to be loaded to constrain desired fO2 values was verified by
CoPd alloy redox sensor experiments to be accurate within ±0.3 log units for the pressure (P) – temperature (T) range of 940–2060 bar and 800–1100 ∘C. As hydrogen can be slowly lost from the pressure
medium due to diffusion through the vessel walls at high T, we also
determined the hydrogen permeability of the MHC alloy as a function of T. The such-obtained hydrogen permeability equation for the MHC alloy can be used to determine the rate of fO2 increase for any MHC pressure vessel configuration. As the rate of fO2 increase is slow (e.g., 0.36 log units per day in our setup at T= 1000 ∘C), we propose that H2 addition to the Ar pressure medium is an effective way to accurately impose fO2 in many types of experiments conducted in MHC vessels allowing experimentation up to T= 1200 ∘C and P= 300 MPa.
Storylines of the 2018 Northern Hemisphere heat wave at pre-industrial and higher global warming levels
Authors: Wehrli Kathrin , Hauser Mathias , Seneviratne Sonia I.
Published: February 2020

Abstract. Extreme temperatures were experienced over a large part of the Northern Hemisphere during the 2018 boreal summer (hereafter referred to as NH2018 event), leading to major impacts to agriculture and society in the affected countries. Previous studies highlighted both the anomalous atmospheric circulation patterns during the event and the background warming due to human greenhouse gas emissions as main drivers for the event. In this study, we present Earth System Model experiments investigating different storylines of the NH2018 event given the same atmospheric circulation and alternative background global warming for: no human imprint, the 2018 conditions, and different mean global warming levels (1.5 °C, 2 °C, 3 °C, and 4 °C). The results reveal that the human-induced background warming was a strong contributor to the intensity of the NH2018 event, and that resulting extremes under similar atmospheric circulation conditions at higher levels of global warming would reach very dangerous levels. About 32 % (61 %) of the inhabited or agricultural area in the investigated region would reach maximum temperatures over 40 °C under 2 °C (4 °C) of global warming and similar atmospheric circulation conditions.
Global distribution of photosynthetically available radiation on the seafloor
Authors: Gattuso Jean-Pierre , Gentili Bernard , Antoine David , Doxaran David
Published: February 2020

Abstract. A 21-year (1998–2018) continuous monthly data set of the global distribution of light (photosynthetically available radiation; PAR) reaching the seabed is presented. It uses ocean colour and bathymetric data to estimate benthic irradiance, offering critical improvements on a previous data set (Gattuso et al., 2006). The time series is 4 times longer (21 vs 5 years), the spatial resolution is better (pixel size of 4.6 vs 9.3 km at the equator) and the bathymetric resolution is also better (pixel size of 0.46 vs 3.7 km at the equator). The paper describes the theoretical and methodological bases and data processing. This new product is used to estimate the surface area of the sea floor where (1) light does not limit the distribution of photosynthetic benthic organisms and (2) net community production is positive. The complete data set is provided as 14 netCDF files available on PANGAEA (https://doi.pangaea.de/10.1594/PANGAEA.910898). The R package CoastalLight, available on Github (https://github.com/jpgattuso/CoastalLight.git), allows (1) to download geographical and optical data from PANGAEA and (2) to calculate the surface area that receives more than a given threshold of irradiance in three regions (non polar, Arctic and Antarctic). Such surface areas can also be calculated for any sub-region after downloading data from a remotely and freely accessible server.
Intercomparison between the Integrated Urban land Model and the
Noah Urban Canopy Model
Authors: Meng Chunlei , Dou Junxia
Published: February 2020

Abstract. Urban land surface model (ULSM) is an important tool to study the climatic effect of human activity. Now there are two main methods to parameterize the effects of human activity, the coupling method and the integrating method. For the coupled method, the urban canopy model (UCM) was developed and coupled with the land surface model for the natural land surfaces. For the integrated method, the urban land surface model was built directly based on the traditional land surface model. In this paper, the Noah Single Layer Urban Canopy Model (Noah/SLUCM) and the Integrated Urban land Model (IUM) were compared using the observed fluxes data at the 325-meter meteorology tower in Beijing. Through the comparison, the key factors and physical processes of the urban land surface model which have significant impact on the performance of ULSM were found out. The results indicate that the absorbed solar radiation of urban surface was reduced by the solar radiation scattering, the absorption of building roof and wall, and the shading effect of urban canopy and tall buildings. Urban surface roughness length and friction velocity are important in urban sensible heat flux simulation. Urban water balance and impervious surface evaporation (ISE) are important in urban latent heat flux simulation.
Global distribution of hydrologic controls on forest growth
Authors: Roebroek Caspar T. J. , Melsen Lieke A. , Hoek van Dijke Anne J. , Fan Ying , Teuling Adriaan J.
Published: February 2020

Abstract. Vegetation provides key ecosystem services and is an important component in the hydrological cycle. Traditionally, the global distribution of vegetation is explained through water availability by precipitation. Locally, however, groundwater can aid growth by providing an extra water source (e.g. oases) or hinder growth by presenting a barrier to root expansion (e.g. swamps). In this study we analysed the global correlation between precipitation, groundwater and forest growth, approximated by the fraction of absorbed photosynthetically active radiation, and linked this to climate and landscape position. The results show that at the continental scale, precipitation is the main driver of forest productivity; wetter climates support higher energy absorption and consequentially more growth. But within all climates, landscape position substantially alters the growth patterns both positively and negatively. The influence of the landscape on vegetation growth varies over climate. The results display the importance of analysing vegetation growth in a climate-landscape continuum.
A data-based predictive model for spatiotemporal variability in stream water quality
Authors: Guo Danlu , Lintern Anna , Webb J. Angus , Ryu Dongryeol , Bende-Michl Ulrike , Liu Shuci , Western Andrew William
Published: February 2020

Abstract. Our current capacity to model stream water quality is limited – particularly
at large spatial scales across multiple catchments. To address this, we
developed a Bayesian hierarchical statistical model to simulate the
spatiotemporal variability in stream water quality across the state of
Victoria, Australia. The model was developed using monthly water quality
monitoring data over 21 years and across 102 catchments (which span over
130 000 km2). The modeling focused on six key water quality
constituents: total suspended solids (TSS), total phosphorus (TP),
filterable reactive phosphorus (FRP), total Kjeldahl nitrogen (TKN),
nitrate–nitrite (NOx) and electrical conductivity (EC). The model
structure was informed by knowledge of the key factors driving water quality
variation, which were identified in two preceding studies using the same
dataset. Apart from FRP, which is hardly explained (19.9 %), the model
explains 38.2 % (NOx) to 88.6 % (EC) of the total spatiotemporal
variability in water quality. Across constituents, the model generally
captures over half of the observed spatial variability; the temporal variability
remains largely unexplained across all catchments, although long-term trends
are well captured. The model is best used to predict proportional changes in
water quality on a Box–Cox-transformed scale, but it can have substantial bias
if used to predict absolute values for high concentrations. This model can
assist catchment management by (1) identifying hot spots and hot moments for
waterway pollution; (2) predicting the effects of catchment changes on water
quality, e.g., urbanization or forestation; and (3) identifying and explaining
major water quality trends and changes. Further model improvements should
focus on the following: (1) alternative statistical model structures to improve fitting
for truncated data (for constituents where a large amount of data fall below the
detection limit); and (2) better representation of nonconservative
constituents (e.g., FRP) by accounting for important biogeochemical
processes.
Determination of the single point precision associated with tactile gear measurements in scanning mode
Authors: Müller Andreas Michael , Hausotte Tino
Published: February 2020

Abstract. The framework of the single point uncertainty developed at the Institute of Manufacturing Metrology (FMT) presents a methodology to determine and evaluate the local measurement uncertainty for a measurement setup by local comparison of a measurement series with an associated reference geometry. This approach, which was originally developed and optimized for the processing of complete areal measurements of work pieces using industrial X-ray computed tomography, was now also extended to line scans found in dimensional testing using tactile coordinate measuring machines (CMMs). The targets of the investigation are spur (involute) steel gear wheels, which can be dimensionally characterized by both helix and profile scans using a CMM in scanning mode in combination with a rotatory table. A second measurement procedure is characterized by a single scan of the complete gear profile without the usage of a rotatory table, using the “free-form scan” CMM functionality. The modification of the single point uncertainty framework in order to determine the single point precision of repeated gear wheel measurements was implemented successfully for gear measurements using the Zeiss Gear Pro evaluation software in combination with a rotatory table as well as unassisted free-form scans of the same gear. The examinations yielded abnormally high random measurement errors, which could not fully be explained within our examinations and was for the most part caused by the accuracy of the used rotatory table of the CMM. The alternative measurement method showed that the CMM system is capable of measuring very precisely in scanning mode if the changes in the curvature of the scan trajectory are favourable.
Study of electron spectral diffusion process under DNP conditions by ELDOR spectroscopy focusing on the 14N Solid Effect
Authors: Ramirez Cohen Marie , Feintuch Akiva , Goldfarb Daniella , Vega Shimon
Published: February 2020

Abstract. Electron spectral diffusion (eSD) plays an important role in solid state, static DNP with polarizers having in-homogeneously broadened EPR spectra, such as nitroxide radicals. It affects the electron spin polarization gradient within the EPR spectrum during microwave irradiation and thereby determines the effectiveness of the DNP process via the so called indirect cross effect (iCE) mechanism. The electron depolarization profile can be measured by Electron-Electron Double Resonance (ELDOR) experiments and a theoretical framework for deriving eSD parameters from ELDOR spectra and employing them to calculate DNP profiles has been developed. The inclusion of electron depolarization arising from the 14N Solid Effect (SE) has not yet been taken into account in this theoretical framework and is the subject of the present work. The 14N SE depolarization was studied using W-band ELDOR of a 0.5 mM TEMPOL solution, where eSD is negligible, taking into account the hyperfine interaction of both 14N and 1H nuclei, the long microwave irradiation applied under DNP conditions and electron and nuclear relaxation. The results of this analysis were then used in simulations of ELDOR spectra of 10 and 20 mM TEMPOL solutions, where eSD is significant using the eSD model and the SE contributions were added ad-hoc employing the 1H and 14N frequencies and their combinations, as found from the analysis of the 0.5 mM sample. This approach worked well for the 20 mM solution where a good fit for all ELDOR spectra recorded along the EPR spectrum was obtained and the inclusion of the 14N SE mechanism improved the agreement with the experimental spectra. For the 10 mM solution, simulations of the ELDOR spectra recorded along the gz position gave a lower quality fit than for spectra recorded in the center of the EPR spectrum, suggesting that the simple approach used to the SE of the 14N contribution, when its contribution is high, is lacking as the anisotropy of its magnetic interactions has not been considered explicitly.
The 22 December 2018 Mount Anak Krakatau volcanogenic tsunami on Sunda Strait coasts, Indonesia: tsunami and damage characteristics
Authors:   Syamsidik,   Benazir, Luthfi Mumtaz , Suppasri Anawat , Comfort Louise K.
Published: February 2020

Abstract. On 22 December 2018, a tsunami was generated from the Mount Anak Krakatau
area that was caused by volcanic flank failures. The tsunami had severe
impacts on the western coast of Banten and the southern coasts of Lampung in
Indonesia. A series of surveys to measure the impacts of the tsunami was
started 3 d after the tsunami and lasted for 10 d. Immediate
investigations allowed the collection of relatively authentic images of the
tsunami impacts before the clearing process started. This article
investigates the impacts of the 2018 Sunda Strait tsunami on the affected
areas and presents an analysis of the impacts of pure hydrodynamic tsunami
forces on buildings. Impacts of the tsunami were expected to exhibit
different characteristics than those found following the 2004 Indian Ocean
tsunami in Aceh. Data were collected from 117 flow depths along the Banten
and Lampung coasts. Furthermore, 98 buildings or houses were assessed for
damage. Results of this study revealed that the flow depths were higher in
Banten than in Lampung. Directions of the tsunami arrays created by the
complex bathymetry around the strait caused these differences.
Tsunami-induced damage to buildings was mostly the result of impact forces
and drag forces. Damping forces could not be associated with the damage.
The tsunami warning system in Indonesia should be extended to anticipate
non-seismic tsunamis, such as landslides and volcanic processes driven by
tsunamis. The lack of a tsunami warning during the first few minutes after the
generation of the first wave led to a significant number of human casualties
in both of the affected areas.
Wide sensitive area of small foreshocks
Authors: Chen Chieh-Hung , Sun Yang-Yi , Wen Strong , Han Peng , Lin Li-Ching , Yu Huai-Zhong , Zhang XueMin , Gao Yongxin , Tang Chi-Chia , Lin Cheng-Horng , Liu Jann-Yenq
Published: February 2020

Abstract. Scientists demystify stress changes within tens of days before a mainshock and often utilize its foreshock as an indicator. Typically, foreshocks are detected near fault zones, which may be due to the distribution of seismometers. This study investigates changes in seismicity far from mainshocks by examining tens of thousands of M >= 2 quakes that were monitored by dense seismic arrays for more than 10 years in Taiwan and Japan. The quakes occurred within epicentral distances ranging from 0 km to 400 km during a period of 60 days before and after the mainshocks that are utilized to exhibit common behaviors of seismicity in the spatiotemporal domain. The superimposition results show that wide areas exhibit increased seismicity associated with mainshocks being more than 50 times to areas of the fault rupture. The seismicity increase initially concentrates in the fault zones, and gradually expands outward to over 50 km away from the epicenters approximately 40 days before the mainshocks. The seismicity increases more rapidly around the fault zones approximately 20 days before the mainshocks. The stressed crust triggers resonance at frequencies varying from ~ 3 × 10−4 Hz to ~ 10−3 Hz (i.e., variable frequency) along with earthquake-related stress that migrates from exterior areas to approach the fault zones. The variable frequency is determined by the observation of continuous seismic waveforms through the superimposition processes and is further supported by the resonant frequency model. These results suggest that the variable frequency of ground vibrations is a function of areas with increased seismicity leading to earthquakes.
Increased LLVP density recovered by seismologically constrained gravity inversion
Authors: Szwillus Wolfgang , Ebbing Jörg , Steinberger Bernhard
Published: February 2020

Abstract. The nature and origin of the two Large Low Velocity Provinces in the lowest part of the mantle remain controversial. They have been interpreted as a purely thermal feature, accumulation of subducted oceanic lithosphere or a primordial zone of iron enrichment. Information regarding the density of the LLVPs would help to constrain a possible explanation. In this work, we perform a density inversion for the entire mantle, by constraining the geometry of potential density anomalies using tomographic vote maps. Vote maps describe the geometry of potential density anomalies according to their agreement of multiple seismic tomographies, hence not depending on a single representation. Therefore, the geometries used for inversion are features observed in most tomographies. We use linear inversion and determine the regularization parameters using cross-validation. Two different input fields are used to study the sensitivity of the mantle density results to the treatment of the lithosphere. We find the best data fit is achieved if we assume that the lithosphere is in isostatic balance. The estimated densities obtained for the LLVPs are systematically positive density anomalies for the LLVPs in the lower 800–1000 km of the mantle, which would indicate a chemical component for the origin of the LLVPs. Both iron-enrichment and a MORB contribution are in accordance with our data, but the required super-adiabatic temperature anomalies for MORB would be close to 1000 K.
Acoustic Emission investigation for avalanche formation and
release: A case study of dry-slab avalanche event in Great Himalaya
Authors: Kapil Jagdish , Sharma Sakshi , Singh Karmjit , Shahi Jangvir Singh , Arora Rama
Published: February 2020

Abstract. Non-invasive monitoring of avalanche formation and release processes, through the use of Acoustic Emission (AE) technique, has been a research challenge since long time. In present investigation AE technique is implemented to monitor the avalanche formation and release processes through a case study of a natural avalanche event reported in Great Himalaya. The specialized AE sensor-arrestor arrays, established over the avalanche starting zone, in conjunction to a high speed multichannel AE acquisition system have successfully recorded the avalanche event passed through the course of instability development followed by release of avalanche. A new method is devised to compute the AE based instability index, and same has been applied to quantify the instability levels of a snowpack. The prominent AE parameters and instability indices are analyzed for different window scales with respect to different AE sensors. The effect of nivological and meteorological conditions and pit analyses collected during the avalanche formation process is also discussed. The critical instability was triggered possibly due to the excessive loading (during snowfall) of an unstable snowpack consisting of persistent weak layers which led to the avalanche release. An abnormal and abrupt increase in the AE activity was observed prior to the avalanche release. The increasing trends in instability indices have shown a good correlation to the avalanche formation and a sharp jump in instability index is attributed to a particular transition occurring across two different instability states of the snowpack. Thus, five conceptual states of snowpack are identified for instability evolution corresponding to four different transitions during avalanche formation and release processes.
Exploitation of the far-offshore wind energy resource by fleets of energy ships. Part A. Energy ship design and performance
Authors: Babarit Aurélien , Clodic Gaël , Delvoye Simon , Gilloteaux Jean-Christophe
Published: February 2020

Abstract. This paper deals with a new concept for the conversion of far-offshore wind energy into sustainable fuel. It relies on autonomously sailing energy ships and manned support tankers. Energy ships are wind-propelled. They generate electricity using water turbines attached underneath their hull. Since energy ships are not grid-connected, they include onboard power-to-X plants for storage of the produced energy. In the present work, the energy vector is methanol. The aim of the paper is to propose an energy ship design and to provide an estimate for its energy performance as function of the wind conditions. The energy performance assessment is based on a numerical model which is described in the paper. Results show that the wind energy-to-methanol (chemical energy) conversion efficiency is 24 % and that such energy ship deployed in the North Atlantic Ocean could produce approximately 5 GWh per annum of chemical energy (900 tonnes of methanol per annum).