bluuebunny/crossref_metadata_2025 huggingface dataset:
Loss of the FOXP1 Transcription Factor Leads to Deregulation of B Lymphocyte Development and Function at Multiple Stages
Authors: Dekker Joseph D , Baracho Gisele V , Zhu Zilu , Ippolito Gregory C , Schmitz Robert J , Rickert Robert C , Tucker Haley O
Published: October 2019

The FOXP1 transcription factor is expressed throughout B cell development until its extinction just prior to terminal differentiation. Foxp1 nulls die of cardiac defects at midgestation, but adult rescue via fetal liver transfer led to a strong pre–B cell block. To circumvent these limitations and to investigate FOXP1 function at later stages of B cell differentiation, we generated and analyzed floxed (F) Foxp1 alleles deleted at pro–B, transitional (T) 1, and mature B cell stages. Mb-1cre–mediated deletion of Foxp1F/F confirmed its requirement for pro–B to pre–B transition. Cd21- and Cd19cre deletion led to significant reduction of germinal center formation and a second block in differentiation at the T2/marginal zone precursor stage. T-dependent and -independent immunization of FOXP1 mutants led to reduction of Ag-specific IgM, whereas responses of class-switched Abs were unimpaired. Yet, unexpectedly, plasmablast and plasma cell numbers were significantly increased by in vitro BCR stimulation of Foxp1F/F splenic follicular B cells but rapidly lost, as they were highly prone to apoptosis. RNA sequencing, gene set enrichment analysis, and chromatin immunoprecipitation sequencing analyses revealed strong enrichment for signatures related to downregulation of immune responses, apoptosis, and germinal center biology, including direct activation of Bcl6 and downregulation of Aicda/AID, the primary effector of somatic hypermutation, and class-switch recombination. These observations support a role for FOXP1 as a direct transcriptional regulator at key steps underlying B cell development in the mouse.
Distinct Host–Mycobacterial Pathogen Interactions between Resistant Adult and Tolerant Tadpole Life Stages of Xenopus laevis
Authors: Rhoo Kun Hyoe , Edholm Eva-Stina , Forzán María J. , Khan Adil , Waddle Anthony W. , Pavelka Martin S. , Robert Jacques
Published: October 2019

Mycobacterium marinum is a promiscuous pathogen infecting many vertebrates, including humans, whose persistent infections are problematic for aquaculture and public health. Among unsettled aspects of host–pathogen interactions, the respective roles of conventional and innate-like T (iT) cells in host defenses against M. marinum remain unclear. In this study, we developed an infection model system in the amphibian Xenopus laevis to study host responses to M. marinum at two distinct life stages, tadpole and adult. Adult frogs possess efficient conventional T cell–mediated immunity, whereas tadpoles predominantly rely on iT cells. We hypothesized that tadpoles are more susceptible and elicit weaker immune responses to M. marinum than adults. However, our results show that, although anti–M. marinum immune responses between tadpoles and adults are different, tadpoles are as resistant to M. marinum inoculation as adult frogs. M. marinum inoculation triggered a robust proinflammatory CD8+ T cell response in adults, whereas tadpoles elicited only a noninflammatory CD8 negative- and iT cell–mediated response. Furthermore, adult anti–M. marinum responses induced active granuloma formation with abundant T cell infiltration and were associated with significantly reduced M. marinum loads. This is reminiscent of local CD8+ T cell response in lung granulomas of human tuberculosis patients. In contrast, tadpoles rarely exhibited granulomas and tolerated persistent M. marinum accumulation. Gene expression profiling confirmed poor tadpole CD8+ T cell response, contrasting with the marked increase in transcript levels of the anti–M. marinum invariant TCR rearrangement (iVα45-Jα1.14) and of CD4. These data provide novel insights into the critical roles of iT cells in vertebrate antimycobacterial immune response and tolerance to pathogens.
A rare case of takotsubo syndrome within the first day after heart transplantation
Authors: Al Humaid Mohammed , Ahmed Mawada , Galzerano Domenico , Al Hussein Mosaad , Al Admawi Mohammed , Al Buraiki Jehad , Alsergani Hani , Vriz Olga
Published: October 2019

A 39-year-old woman underwent heart transplantation (HTx) for advanced heart failure. The donor was a 36-year-old young woman without past medical history. The first day after HTx, T-waves changes were noted. Echocardiography revealed akinesia/dyskinesia of all basal segments of the two ventricles. Coronary catheterization plus biopsy were done 7 days later showing no coronary obstruction, no rejection and complete recovery of wall motion abnormalities on echocardiogram, suggesting biventricular inverted takotsubo syndrome (TTS). This is a case of TTS during the first day after HTx, with completely denervated heart but because of the inotropic drug support it still represents a target for catecholamine-induced cardiac dysfunction.
An Integrated Nomogram Combining Clinical Factors and Microtubule-Associated Protein 1 Light Chain 3B Expression to Predict Postoperative Prognosis in Patients with Intrahepatic Cholangiocarcinoma
Authors: Chen Liang , Fu Hongyuan , Lu Tongyu , Cai Jianye , Liu Wei , Yao Jia , Liang Jinliang , Zhao Hui , Zhang Jiebin , Zheng Jun , Zhang Yingcai , Yang Yang
Published: October 2019

PurposeMicrotubule-associated protein 1 light chain 3B (LC3B) serves as a key component of autophagy, which is associated with the progression of carcinoma. Yet, it is still unclear whether LC3B is also an independent risk factor for intrahepatic cholangiocarcinoma (ICC). We aim to explore the predictive value of LC3B on prognosis of ICC, and to establish a novel and available nomogram to predict relapse-free survival (RFS) and overall survival (OS) for these patients after curative-intent hepatectomy.Materials and MethodsFrom August 2004 to March 2017, 105 ICC patients were eligibly enrolled in the Third Affiliated Hospital of Sun Yat-sen University. Preoperative clinical information of enrolled patients was collected. Expression LC3B in the ICC specimen was detected by immunohistochemistry.ResultsThe 5-year RFS and OS in this cohort were 15.7% and 29.6%, respectively. On multivariate Cox regression analysis, independent risk factors for 5-year OS were cancer antigen 125, microvascular invasion, LC3B expression and lymph node metastasis. Except for the above 4 factors, neutrophil/lymphocyte ratio and tumor differentiation were independent factors for 5-year RFS. The area under the curve of nomograms for OS and RFS were 0.820 and 0.747, respectively.ConclusionThe nomograms based on LC3B can be considered as effective models to predict postoperative survival for ICC patients.
Relações lógico-inferenciais no uso dos conectivos porque e já que: um estudo comparativo entre Ensino Fundamental e Ensino Superior
Authors: Dos Santos Sabrina Lopes , Garcia Daniela , Maia Marcus
Published: October 2019

This paper presents a comparative study between Elementary School and Undergraduate Education investigating the use of connectives já que and porque in sentences with inferential causal relations established through inductive and deductive logical reasoning. As the acquisition of some connectives is related to schooling and consequent exposure to the written modality, this work can contribute to raising questions about the relationship between the acquisition of this modality and its influence on the way we interpret logical-inferential relations. In this paper, we present a forced-choice judgment test in which participants should choose between the connectives  já que and porque when they are exposed to sentences with direct and indirect causal relationships. Our hypothesis was that, in indirect cause relationships, individuals with more experience in reading would choose já que, but individuals with little experience should choose mainly porque in both cases.
Mother-tongue education, linguistic variation and language processing
Authors: Marcilese Mercedes , Name Cristina , Augusto Marina , Molina Daniele , Armando Raiane
Published: October 2019

This paperexploresan intersection betweenthree main topics: (i) sociolinguistic variation, (ii) variation acquisition and processingaccording toa psycholinguistic approachand (iii) mother-tongue teaching/learning when the two previous factors are taken into account. Nonstandard linguistic varieties coexist in society with a standardized variety that could be defined as the ‘language of education’. The distance between standard forms and the variety acquired by children at home is quite variable and could have an impact on how and when the formal register becomes (or not) part of the range of linguistic speaker’s options.In order to address these issues, we provide experimental results regarding the comprehension and production of two linguistic aspects that show a high variation in Brazilian Portuguese– verbal agreement and anaphoric forms in direct object position – as a function of formal education exposure; we also articulate these results with the concepts of core grammar and marked periphery (Kato, 2005) for a more theoretical discussion.
“Só mais um minutinho, teacher”: planejamento estratégico colaborativo e individual para tarefas orais em L2 em uma escola pública
Authors: Zaccaron Rafael , Xhafaj Donesca Cristina Puntel , D'Ely Raquel Carolina de Souza Ferraz
Published: October 2019

Bearingin mind the challenges involved in speech production (LEVELT, 1989), especially in the L2 (KORMOS, 2014), this study examines strategic planning (ELLIS, 2005) and its impact on the performance of learners of English as an L2 in an oral task carried out after they had planned it individually or collaboratively. Drawing from the output hypothesis (SWAIN, 1985), this piece of research analysed quantitative and qualitative data from the narratives produced by 17 high school students. The quantitative analysis showed a statistically significant advantage for the outcome variable when the participants planned collaboratively. At the same time, while the results for fluency and accuracy were not statistically significant, they also favoured the same planning condition. The qualitative data indicated wide acceptance of oral tasks with the use of WhatsApp. It is suggested that the adoption of tasks that include strategic planning as a means to lessen the attentional burden involved in L2 speech production (FORTKAMP, 2000) may be an attractive pedagogical resource to help English students to learn the language in a contextualized way.
Phonemic awareness in an oral German-origin Brazilian language: a study of Hunsrückisch and German bilinguals
Authors: Limberger Bernardo K. , Azevedo Aline Fay , Ferstl Evelyn C. , Buchweitz Augusto
Published: October 2019

Phonemic awareness is the ability to notice and manipulate language sounds in their base form (phonemes). It is associated with emerging literacy skills and predictive of skilled reading. The aim of the present study was to investigate phonemic awareness in German and its association with speaking a German-origin, but predominantly unwritten language. We investigated speakers of Hunsrückisch, a Brazilian minority language predominantly used in its spoken form. Participants were literate Brazilian Portuguese speakers who spoke Hunsrückisch and German or Hunsrückisch only. The results show faster, more accurate performance in the phonemic awareness task among participants who spoke Hunsrückisch and German, relative to those who spoke Hunsrückisch only. Participants who spoke Hunsrückisch only were able to perform the phonemic awareness tasks but having learned to read and write in German allowed for faster, more accurate performance, especially in relation to pseudowords.
Aprendizagem da leitura e da escrita à luz da psicolinguística genética
Authors: Pinto Maria da Graça Lisboa Castro
Published: October 2019

The aim of this paper is to show that learning to speak and write is based on cognitive foundations, apart from the social and neurological aspects which should not be underestimated. The paper should thus be read from the perspective of genetic psycholinguistics, which places special emphasis on the cognitive development that underpins oral and written language. I intend to highlight the conditions that are required for successful entry into writing, ranging from mastery of the notions of number and class and their relationships of equivalence and inclusion, to the ability for cognitive decentralisation that accompanies abstraction, which is indispensable to the symbolisation that is at the origin of the phonographic code. This paper consists of two parts: the first is focused on theoretical notions without which it would be difficult to understand the perspective adopted, and the second is more practical, documented by a battery of tests that aim to evaluate the child upon entry into school, considering the aspects listed.
Do contrato ao status: as terras indígenas e o Supremo Tribunal Federal
Authors: Lewandowski Andressa
Published: October 2019

O artigo tem por objetivo discutir a noção constitucional de terra tradicionalmente ocupada, a partir dos fundamentos jurídicos, antropológicos e indígenas em que se ancoram os processos de demarcação de terras indígenas, explorando os limites das intepretações recentes em torno do conceito.
Wintertime aerosol measurements during the Chilean Coastal Orographic Precipitation Experiment
Authors: Fults Sara Lynn , Massmann Adam K. , Montecinos Aldo , Andrews Elisabeth , Kingsmill David E. , Minder Justin R. , Garreaud René D. , Snider Jefferson R.
Published: October 2019

Abstract. The Chilean Coastal Orographic Precipitation Experiment (CCOPE) was a
3-month field campaign (June, July and August 2015) that investigated
wintertime coastal rain events. Reported here are analyses of aerosol
measurements made at a coastal site during CCOPE. The aerosol monitoring
site was located near Arauco, Chile. Aerosol number concentrations and
aerosol size distributions were acquired with a condensation particle
counter (CPC) and an ultra high sensitivity aerosol spectrometer (UHSAS).
Arauco CPC data were compared to values measured at the NOAA observatory
Trinidad Head (THD) on the northern Pacific coast of California. The
winter-averaged CPC concentration at Arauco is 2971 ± 1802 cm−3; at THD the average is 1059 ± 855 cm−3.
Despite the typically more pristine South Pacific region, the Arauco
average is larger than at THD (p<0.01). Aerosol size distributions
acquired during episodes of onshore flow were analyzed with Köhler
theory and used to parameterize cloud condensation nuclei activation
spectra. In addition, sea salt aerosol (SSA) concentration was parameterized
as a function of sea surface wind speed. It is anticipated these
parameterizations will be applied in modeling of wintertime Chilean coastal
precipitation.
Measurements to determine mixing state of black carbon emitted
from the 2017/2018 California wildfires and urban Los Angeles
Authors: Ko Joseph , Krasowsky Trevor , Ban-Weiss George
Published: October 2019

Abstract. The effects of atmospheric black carbon (BC) on climate and public health have been well established, but large uncertainties remain regarding the extent of BC’s impacts at different temporal and spatial scales. These uncertainties are largely due to BC’s heterogeneous nature in terms of its spatiotemporal distribution, mixing state, and coating properties. Here, we seek to further understand the mixing state evolution of BC emitted from various sources and aged over different timescales using field measurements in the Los Angeles region. We measured refractory black carbon (rBC) with a single-particle soot photometer (SP2) on Catalina Island, California (~ 70 km southwest of downtown Los Angeles) during three different time periods. During the first campaign (September 2017), westerly winds dominated and thus the sampling location was upwind of the dominant regional sources of BC (i.e., urban emissions from the Los Angeles basin). In the second and third campaigns (December 2017, November 2018), atypical wind conditions caused measured rBC to include important contributions from large wildfires in California and urban emission from the Los Angeles basin. We observed a larger number fraction of thickly coated particles (fBC) and increased coating thickness (CTBC) during the first campaign (~ 0.27 and ~ 36 nm, respectively), and during portions of the third campaign when we suspect that rBC was transported long-range from the Camp Fire in Northern California (~ 0.35 and ~ 52 nm, respectively), compared to other time periods. In contrast, during periods when we suspect that measured rBC was dominated by Southern California fires or urban emissions, both fBC and CTBC were significantly lower, with a mean fBC of ~ 0.03 and median CTBC ranging from ~ 0 to 10 nm. From our rBC measurements and meteorological analyses, we conclude that an aging timescale on the order of ~ hours is not long enough for rBC to become thickly coated under the range of sources sampled and atmospheric conditions during this campaign. On average, we found that measured rBC had to age more than a day to become thickly-coated. Aging timescales for developing thick coatings were found to be longer in this study relative to a number of previous observational studies conducted with an SP2, suggesting that rBC aging is heavily impacted by regional atmospheric context.
Ceilometers as planetary boundary layer detectors and a
corrective tool for ECMWF and COSMO NWP models
Authors: Uzan Leenes , Egert Smadar , Khain Pavel , Levi Yoav , Vladislavsky Elyakom , Alpert Pinhas
Published: October 2019

Abstract. The growing importance of the planetary boundary layer (PBL) height detection is apparent in various fields, from air pollution analysis to weather prediction. In recent years micro-lidars such as ceilometers have been recognized as an efficient tool for such measurements. Here, the daytime summer PBL height is measured by eight ceilometers throughout Israel, along with with radiosonde profiles, the global IFS model, and the regional COSMO model. The analysis focused on three PBL height evaluation methods: the bulk Richardson method, the parcel method, and the wavelet covariance transform method. The best agreement between the PBL heights derived from a single radiosonde site on 33 summer days was found by the adjacent ceilometer (mean error = 12 m, RMSE = 97 m). Spatial analysis of the PBL heights derived from the models on 13 days in reference to five ceilometer measurement sites revealed COSMO evaluations by the bulk Richardson method (COSMOR) produced the best results for both flat (mean error = 19 m, RMSE = 203 m) and elevated terrain (mean error = −6 m, RMSE = 251 m). To improve COSMOR results, a regression tool was assimilated based on the PBL height difference between COSMOR and ceilometers. The regression is based on the altitude and distance from the shoreline for eight ceilometer sites.
Formation of highly oxygenated organic molecules from chlorine atom
initiated oxidation of alpha-pinene
Authors: Wang Yonghong , Riva Matthieu , Xie Hongbin , Heikkinen Liine , Schallhart Simon , Zha Qiaozhi , Yan Chao , He Xucheng , Peräkylä Otso , Ehn Mikael
Published: October 2019

Abstract. Highly oxygenated organic molecules (HOMs) from atmospheric oxidation of alpha-pinene can irreversibly condense to particles and contribute to secondary organic aerosol (SOA) formation. Recently, the formation of nitryl chloride (ClNO2) from heterogeneous reactions, followed by its subsequent photolysis is suggested to be an important source of chlorine atoms in many parts of the atmosphere. However, the oxidation of monoterpenes such as alpha-pinene by chlorine atoms has received very little attention, and the ability of this reaction to form HOM is completely unstudied. Here, chamber experiments were conducted with alpha-pinene and chlorine under low and high nitrogen oxide (NOx) conditions. A NO3-based CI-APi-TOF was used to measure HOM products. Clear distributions of monomers with 9–10 carbon atoms and dimers with 18–20 carbon atoms were observed under low NOx conditions. With increased concentration of NOx within the chamber, the formation of dimers was suppressed due to the reactions of peroxy radicals with NO. We estimated the HOM yields from chlorine-initiated oxidation of alpha-pinene under low-NOx conditions to be around 1.8 %, though with a substantial uncertainty range (0.8–4 %) due to lack of suitable calibration methods. Corresponding yields at high NOx could not be determined because of concurrent ozonolysis reactions. Our study demonstrates that chlorine atoms also initiated oxidation of alpha-pinene and yields low volatility organic compounds.
Protein aggregates nucleate ice: the example of apoferritin
Authors: Cascajo-Castresana María , David Robert O. , Iriarte-Alonso Maiara A. , Bittner Alexander M. , Marcolli Claudia
Published: October 2019

Abstract. Biological material has gained increasing attention recently as a source of ice-nucleating particles that may account for cloud glaciation at moderate supercooling. While the ice-nucleation (IN) ability of some bacteria can be related to membrane-bound proteins with epitaxial fit to ice, little is known about the IN active entities present in biological material in general. To elucidate the potential of proteins and viruses to contribute to the IN activity of biological material, we performed bulk freezing experiments with the newly developed drop freezing assay DRINCZ, which allows the simultaneous cooling of 96 sample aliquots in a chilled ethanol bath. We performed a screening of common proteins, namely the iron storage protein ferritin and its iron-free counterpart apoferritin, the milk protein casein, the egg protein ovalbumin, two hydrophobins, and a yeast ice-binding protein, all of which revealed IN activity with active site densities > 0.1 mg−1 at 10 °C. The tobacco mosaic virus, a plant virus based on helically assembled proteins, also proved to be IN active with active site densities increasing from 100 mg−1 at 14 °C to 10,000 mg−1 at −20 °C. Among the screened proteins, the IN activity of horse spleen ferritin and apoferritin, which form cages of 24 co-assembled protein subunits, proved to be outstanding with active site densities > 10 mg−1 at −5 °C. Investigation of the pH dependence and heat resistance of the apoferritin sample confirmed the proteinaceous nature of its IN active entities but excluded the correctly folded cage monomer as the IN active species. A dilution series of apoferritin in water revealed two distinct freezing ranges, an upper one from −4 to −11 °C and a lower one from −11 to −21 °C. Dynamic light scattering measurements related the upper freezing range to ice-nucleating sites residing on aggregates and the lower freezing range to sites located on misfolded cage monomers or oligomers. The sites proved to persist during several freeze-thaw cycles performed with the same sample aliquots. Based on these results, IN activity seems to be a common feature of diverse proteins, irrespective of their function, but arising only rarely, most probably through defective folding or aggregation to structures that are IN active.
Shipborne measurements of Antarctic submicron organic aerosols: an NMR perspective linking multiple sources and bioregions
Authors: Decesari Stefano , Paglione Marco , Rinaldi Matteo , Dall'Osto Manuel , Simó Rafel , Zanca Nicola , Volpi Francesca , Facchini Maria Cristina , Hoffmann Thorsten , Götz Sven , Kampf Christopher Johannes , O’Dowd Colin , Ovadnevaite Jurgita , Ceburnis Darius , Tagliavini Emilio
Published: October 2019

Abstract. The concentrations of submicron aerosol particles in maritime regions around Antarctica are influenced by the extent of sea ice. This effect is two way: on one side, sea ice regulates the production of particles by sea spray (primary aerosols) while, on the other side, it hosts complex communities of organisms emitting precursors for secondary particles. Past studies documenting the chemical composition of fine aerosols in Antarctica indicate various potential primary and secondary sources active in coastal areas, in offshore marine regions as well as in the sea ice itself. In particular, beside the well-known sources of organic and sulfur material originating from the oxidation of dimethyl-sulfide (DMS) produced by microalgae, recent findings obtained during the 2015 PEGASO cruise suggest that nitrogen-containing organic compounds are also produced by the microbiota colonizing the marginal ice zone. To complement the aerosol source apportionment performed using online mass spectrometric techniques, here we discuss the outcomes of offline spectroscopic analysis performed by nuclear magnetic resonance (NMR) spectroscopy. In this study we (i) present the composition of ambient aerosols over open ocean waters across bioregions, and compared it to the composition of (ii) seawater samples and (iii) bubble bursting aerosols produced in a sea spray chamber on board the ship. Our results show that the process of aerosolization in the tank enriches primary marine particles with lipids and sugars while depleting them of free aminoacids, providing an explanation for why aminoacids occurred only at trace concentrations in the marine aerosol samples analyzed. The analysis of water-soluble organic carbon (WSOC) in ambient submicron aerosol samples shows distinct NMR fingerprints for three bioregions: 1) the open Southern Ocean pelagic environments, in which aerosols are enriched with primary marine particles containing lipids and sugars; 2) sympagic areas in the Weddell Sea where secondary organic compounds, including methanesulfonic acid and semivolatile amines abound in the aerosol composition; and 3) terrestrial coastal areas, traced by sugars such as sucrose, emitted by land vegetation. Finally, a new biogenic chemical marker, creatinine, was identified in the samples from the Weddell Sea, providing another confirmation of the importance of nitrogen-containing metabolites in Antarctic polar aerosols.
Intercomparison of aerosol volume size distributions derived from AERONET ground-based remote sensing and LARGE in situ aircraft profiles during the 2011–2014 DRAGON and DISCOVER-AQ experiments
Authors: Schafer Joel S. , Eck Tom F. , Holben Brent N. , Thornhill Kenneth L. , Ziemba Luke D. , Sawamura Patricia , Moore Richard H. , Slutsker Ilya , Anderson Bruce E. , Sinyuk Alexander , Giles David M. , Smirnov Alexander , Beyersdorf Andreas J. , Winstead Edward L.
Published: October 2019

Abstract. Aerosol volume size distribution (VSD) retrievals from the Aerosol Robotic Network (AERONET) aerosol monitoring network were obtained during multiple DRAGON (Distributed Regional Aerosol Gridded Observational Network) campaigns conducted in Maryland, California, Texas and Colorado from 2011 to 2014. These VSD retrievals from the field campaigns were used to make comparisons with near-simultaneous in situ samples from aircraft profiles carried out by the NASA Langley Aerosol Group Experiment (LARGE) team as part of four campaigns comprising the DISCOVER-AQ (Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality) experiments. For coincident (±1 h) measurements there were a total of 91 profile-averaged fine-mode size distributions acquired with the LARGE ultra-high sensitivity aerosol spectrometer (UHSAS) instrument matched to 153 AERONET size distributions retrieved from almucantars at 22 different ground sites. These volume size distributions were characterized by two fine-mode parameters, the radius of peak concentration (rpeak_conc) and the VSD fine-mode width (widthpeak_conc). The AERONET retrievals of these VSD fine-mode parameters, derived from ground-based almucantar sun photometer data, represent ambient humidity values while the LARGE aircraft spiral profile retrievals provide dried aerosol (relative humidity; RH <20 %) values. For the combined multiple campaign dataset, the average difference in rpeak_conc was 0.033±0.035 µm (ambient AERONET values were 15.8 % larger than dried LARGE values), and the average difference in widthpeak_conc was 0.042±0.039 µm (AERONET values were 25.7 % larger). For a subset of aircraft data, the LARGE data were adjusted to account for ambient humidification. For these cases, the AERONET–LARGE average differences were smaller, with rpeak_conc differing by 0.011±0.019 µm (AERONET values were 5.2 % larger) and widthpeak_conc average differences equal to 0.030±0.037 µm (AERONET values were 15.8 % larger).
Measurement techniques for identifying and quantifying hydroxymethanesulfonate (HMS) in an aqueous matrix and particulate matter using aerosol mass spectrometry and ion chromatography
Authors: Dovrou Eleni , Lim Christopher Y. , Canagaratna Manjula R. , Kroll Jesse H. , Worsnop Douglas R. , Keutsch Frank N.
Published: October 2019

Abstract. Oxidation of sulfur dioxide
(SO2) in the gas phase and in cloud and fog
water leads to the formation of sulfate that contributes to ambient
particulate matter (PM). For severe haze events with low-light conditions,
current models underestimate the levels of sulfate formation that occur
exclusively via the oxidation of sulfur dioxide. We show here that
measurement techniques commonly used in the field to analyze PM composition
can fail to efficiently separate sulfur-containing species, resulting in
the possible misidentification of compounds. Hydroxymethanesulfonate (HMS), a
sulfur(IV) species that can be present in fog and cloud water, has been
largely neglected in both chemical models and field measurements of PM
composition. As HMS is formed without oxidation, it represents a pathway for
SO2 to contribute to PM under low-light
conditions. In this work, we evaluate two techniques for the specific
quantification of HMS and sulfate in PM, ion chromatography (IC) and aerosol
mass spectrometry (AMS). In cases in which the dominant sulfur-containing
species are ammonium sulfate or HMS, differences in AMS fragmentation
patterns can be used to identify HMS. However, the AMS quantification of HMS
in complex ambient mixtures containing multiple inorganic and organic sulfur
species is challenging due to the lack of unique organic fragments and
the variability of fractional contributions of
HxSOy+ ions
as a function of the matrix. We describe an improved IC method that provides
efficient separation of sulfate and HMS and thus allows for the identification and
quantification of both. The results of this work provide a technical
description of the efficiency and limitations of these techniques as well as
a method that enables further studies of the contribution of S(IV)
versus S(VI) species to PM under low-light atmospheric conditions.
Historical droughts in the Qing dynasty (1644–1911) of China and the role of human interventions
Authors: Lin Kuan-Hui Elaine , Wang Pao K. , Pai Pi-Ling , Lin Yu-Shiuan , Wang Chih-Wei
Published: October 2019

Abstract. This study presents a new epistemology to analyze drought chronology through a clear-cut methodology for reconstructing past drought series as well as series for other associated ecological and societal variables. Instead of building grading system based on mixed criteria, this method can facilitate transparency in the reconstruction process and can enable statistical examinations of all variables when building the series. The data used is from the REACHES database, however other archival documentary and index data from independent sources are also applied to understand drought narratives and to cross check and validate the analysis derived from the REACHES. From time series analysis, six severe drought periods are identified in the Qing dynasty, and then spatial analysis is performed to demonstrate spatial distribution of drought and other variables in the six periods as well as social network analysis to reveal connections between drought and other ecological and societal variables. Research results clearly illustrate the role of human intervention to influence the impacts of drought on societal consequences. Particularly, the correlation between drought and socioeconomic is not strong; crop failure and famine are important intermediate factors, meanwhile ecological factor such as locust and disaster relief measures are all imperative to intervene between crop production and famine. Implications of the study on drought impact in provided as well as its significance on historical climatology reconstruction studies.
Centennial-scale monsoon changes since the last deglaciation linked to solar activities and North Atlantic cooling
Authors: Liu Xingxing , Sun Youbin , Vandenberghe Jef , Cheng Peng , Zhang Xu , Gowan Evan J. , Lohmann Gerrit , An Zhisheng
Published: October 2019

Abstract. Rapid monsoon changes since the last deglaciation remain poorly constrained due to the scarcity of geological archives. Here we present a high-resolution scanning X-ray fluorescence (XRF) analysis of a 13.5 m terrace succession on the western Chinese Loess Plateau (CLP) to infer rapid monsoon changes since the last deglaciation. Our results indicate that Rb/Sr and Zr/Rb are sensitive indicators of chemical weathering and wind sorting, respectively, which are further linked to the strength of the East Asia summer and winter monsoon. These two parameters exhibit an anti-phase relationship between the summer and winter monsoon changes on centennial timescale during 16 ∼ 1 ka BP. Comparison of these monsoon changes with solar activity and North Atlantic cooling events reveals that both factors can lead to abrupt changes on the centennial timescale in the early Holocene. During the late Holocene, North Atlantic cooling became the major forcing of centennial monsoon events.
Climate impacts on deglaciation and vegetation dynamics since the Last Glacial Maximum at Moossee (Switzerland)
Authors: Rey Fabian , Gobet Erika , Schwörer Christoph , Hafner Albert , Tinner Willy
Published: October 2019

Abstract. Since the Last Glacial Maximum (LGM, end ca. 19 000 cal BP) Central European plant communities were shaped by changing climatic and anthropogenic disturbances. Understanding long-term ecosystem reorganizations in response to past environmental changes is crucial to draw conclusions about the impact of future climate change. So far, it has been difficult to address the post-deglaciation timing and ecosystem dynamics due to a lack of well-dated and continuous sediment sequences covering the entire period after the LGM. Here, we present a new palaeoecological study with exceptional chronological time control using pollen, spores and microscopic charcoal from Moossee (Swiss Plateau, 521 m a.s.l.) to reconstruct the vegetation and fire history over the last ca. 19 000 years. After lake formation in response to deglaciation, five major pollen-inferred ecosystem rearrangements occurred at ca. 18 800 cal BP (establishment of steppe tundra), 16 000 cal BP (spread of shrub tundra), 14 600 cal BP (expansion of boreal forests), 11 600 cal BP (establishment of first temperate deciduous tree stands composed of e.g. Quercus, Ulmus, Alnus) and 8200 cal BP (first occurence of mesophilous Fagus sylvatica trees). These vegetation shifts were released by climate changes at 19 000, 16 000, 14 700, 11 700 and 8200 cal BP. Vegetation responses occurred with no apparent time lag to climate change, if the mutual chronological uncertainties are considered. This finding is in agreement with further evidence from Southern and Central Europe and might be explained with proximity to the refugia of boreal and temperate trees (< 400 km) and rapid species spreads. Our palynological record sets the beginning of millennial-scale land use with periodically increased fire and agricultural activities of the Neolithic period at ca. 7000 cal BP (5050 cal BC). Subsequently, humans rather than climate triggered changes in vegetation composition and structure. We conclude that Fagus sylvatica forests were resilient to long-term anthropogenic and climatic impacts of the mid and the late Holocene. However, future climate warming and in particular declining moisture availability may cause unprecedented reorganizations of Central European beech-dominated forest ecosystems.
Annual oil palm plantation maps in Malaysia and Indonesia from 2001 to 2016
Authors: Xu Yidi , Yu Le , Li Wei , Ciais Philippe , Cheng Yuqi , Gong Peng
Published: October 2019

Abstract. Increasing global demand of vegetable oils and biofuels results in significant oil palm expansion in Southeast Asia, predominately in Malaysia and Indonesia. The land conversion to oil palm plantations leads to deforestation, loss of biodiversity, and greenhouse gas emission over the past decades. Quantifying the consequences of oil palm expansion requires fine scale and frequently updated datasets of land cover dynamics. Previous studies focused on total changes for a multi-year interval without identifying the exact time of conversion, causing uncertainty in the timing of carbon emission estimates from land cover change. Using Advanced Land Observing Satellite (ALOS) Phased Array Type L-band Synthetic Aperture Radar (PALSAR), ALOS-2 PALSAR-2 and Moderate Resolution Imaging Spectroradiometer (MODIS) datasets, we produced an Annual Oil Palm Area Dataset (AOPD) at 100-meter resolution in Malaysia and Indonesia from 2001 to 2016. We first mapped the oil palm extent using PALSAR/PALSAR-2 data for 2007–2010 and 2015–2016 and then applied a disturbance and recovery algorithm (BFAST) to detect land cover change time-points using MODIS data during the years without PALSAR data (2011–2014 and 2001–2006). The new oil palm land cover maps are assessed to have an accuracy of 86.61 % in the mapping step (2007–2010 and 2015–2016). During the intervening years when MODIS data are used, 75.74 % of the change detected time matched the timing of actual conversion using Google Earth and Landsat images. The AOPD dataset revealed spatiotemporal oil palm dynamics every year and shows that plantations expanded from 2.59 to 6.39 M ha and from 3.00 to 12.66 M ha in Malaysia and Indonesia, respectively (i.e., a net increase of 146.60 % and 322.46 %) between 2001 and 2016. The increasing trends from our dataset are consistent with those from the national inventories, but slightly greater because of inclusion of smallholder oil palm plantations in our dataset. We highlight the capability of combining multiple resolution radar and optical satellite datasets in annual plantation mapping at large extent using image classification and statistical boundary-based change detection to achieve long time-series. The consistent characterization of oil palm dynamics can be further used in downstream applications. The annual oil palm plantation maps from 2001 to 2016 at 100 m resolution is published in the Tagged Image File Format with georeferencing information (GeoTIFF) at https://doi.org/10.5281/zenodo.3467071.
A pan-African high-resolution drought index dataset
Authors: Peng Jian , Dadson Simon , Hirpa Feyera , Dyer Ellen , Lees Thomas , Miralles Diego G. , Vicente-Serrano Sergio M. , Funk Chris
Published: October 2019

Abstract. Droughts in Africa cause severe problems such as crop failure, food shortages, famine, epidemics and even mass migration. To minimize the effects of drought on water and food security over Africa, a high-resolution drought dataset is essential to establish robust drought hazard probabilities and to assess drought vulnerability considering a multi- and cross-sectorial perspective that includes crops, hydrological systems, rangeland, and environmental systems. Such assessments are essential for policy makers, their advisors, and other stakeholders to respond to the pressing humanitarian issues caused by these environmental hazards. In this study, a high spatial resolution Standardized Precipitation-Evapotranspiration Index (SPEI) drought dataset is presented to support these assessments. We compute historical SPEI data based on Climate Hazards group InfraRed Precipitation with Station data (CHIRPS) precipitation estimates and Global Land Evaporation Amsterdam Model (GLEAM) potential evaporation estimates. The high resolution SPEI dataset (SPEI-HR) presented here spans from 1981 to 2016 (36 years) with 5 km spatial resolution over the whole Africa. To facilitate the diagnosis of droughts of different durations, accumulation periods from 1 to 48 months are provided. The quality of the resulting dataset was compared with coarse-resolution SPEI based on Climatic Research Unit (CRU) Time-Series (TS) datasets, and Normalized Difference Vegetation Index (NDVI) calculated from the Global Inventory Monitoring and Modeling System (GIMMS) project, as well as with root zone soil moisture modelled by GLEAM. Agreement found between coarse resolution SPEI from CRU TS (SPEI-CRU) and the developed SPEI-HR provides confidence in the estimation of temporal and spatial variability of droughts in Africa with SPEI-HR. In addition, agreement of SPEI-HR versus NDVI and root zone soil moisture – with average correlation coefficient (R) of 0.54 and 0.77, respectively – further implies that SPEI-HR can provide valuable information to study drought-related processes and societal impacts at sub-basin and district scales in Africa. The dataset is archived in Centre for Environmental Data Analysis (CEDA) with link: https://doi.org/10.5285/bbdfd09a04304158b366777eba0d2aeb (Peng et al., 2019a)
Low power GPS drifters with local storage and GSM modem made from off the shelf components
Authors: Hut Rolf , Thatoe Nwe Win Thanda , Bogaard Thom
Published: October 2019

Abstract. Drifters that track their position are important tools in studying the hydrodynamic behaviour of rivers. Drifters that can be tracked in real time have so far been rather expensive. Recently both GPS receivers and GSM modems have become available at lower prices to tinkering scientists due to the rise of the Open Hardware revolution and the associated Arduino ecosystem. This article serves two goals. Firstly, we provide detailed instructions on how to build a Low Power GPS drifter with local storage and GSM model that we tested in a fieldwork on the confluence of the Chindwin and Ayeyarwady rivers in Myanmar. These instructions allow fellow geoscientists to recreate the device. Secondly, we set the question: "Has the Open Hardware revolution progressed to the point that a low power GPS drifter that wireless transmits its position can be made from Open Hardware component by geoscientists without extensive training or expertise in electrical and software engineering? We feel this question is relevant and timely as more low-cost Open Hardware devices are promoted but in practice applicability often is restricted to the 'tinkering engineer'. We argue that because of the plug and play nature of the components geoscientist should be able to construct these type of devices. However, to get such devices to operate at low power levels that fieldwork often requires detailed (mircro)electrical expertise.
Pysteps: an open-source Python library for probabilistic precipitation nowcasting (v1.0)
Authors: Pulkkinen Seppo , Nerini Daniele , Pérez Hortal Andrés A. , Velasco-Forero Carlos , Seed Alan , Germann Urs , Foresti Loris
Published: October 2019

Abstract. Pysteps is an open-source and community-driven Python library for probabilistic precipitation nowcasting, that is, very-short-range forecasting (0–6 h). The aim of pysteps is to serve two different needs. The first is to provide a modular and well-documented framework for researchers interested in developing new methods for nowcasting and stochastic space–time simulation of precipitation. The second aim is to offer a highly configurable and easily accessible platform for practitioners ranging from weather forecasters to hydrologists. In this sense, pysteps has the potential to become an important component for integrated early warning systems for severe weather. The pysteps library supports various input/output file formats and implements several optical flow methods as well as advanced stochastic generators to produce ensemble nowcasts. In addition, it includes tools for visualizing and post-processing the nowcasts and methods for deterministic, probabilistic and neighborhood forecast verification. The pysteps library is described and its potential is demonstrated using radar composite images from Finland, Switzerland, the United States and Australia. Finally, scientific experiments are carried out to help the reader to understand the pysteps framework and sensitivity to model parameters.
Calculating human thermal comfort and thermal stress in the
PALM model system 6.0
Authors: Fröhlich Dominik , Matzarakis Andreas
Published: October 2019

Abstract. In the frame of the project MOSAIK – Model–based city planning and application in climate change, a German-wide research project within the call Urban Climate Under Change ([UC]2) funded by the German Federal Ministry of Education and Research (BMBF), a biometeorology module was implemented into the PALM model system. The new biometeorology module comprises of methods for the calculation of uv-exposure quantities, a human–biometeorologically weighted mean radiant temperature (Tmrt), as well as for the estimation of human thermal comfort or stress. The latter is achieved through the implementation of the three widely–used thermal indices Perceived Temperature (PT), Universal Thermal Climate Index (UTCI), as well as Physiologically Equivalent Temperature (PET) together with a newly developed instationary index instationary Perceived Temperature (iPT) based on PT for use with the multi–agent model. Comparison calculations were performed for the indices PT, UTCI and PET based on the SkyHelios model and showing PALM calculates higher values in general. This is mostly due to a higher radiational gain leading to higher values of mean radiant temperature. For a more direct comparison, the indices PT, PET and UTCI were calculated by the biometeorology module, as well as the programs provided by the attachment to the VDI guideline 3787, as well as by the RayMan model based on the very same input dataset. Results show deviations below rounding precision (less than 0.1 K) for PET and UTCI and some deviations of up to 2.683 K for PT caused by rounding leading to the selection of a different clothing insulation step in very rare cases (0.027 %).
Mitigation of Model Bias Influences on Wave Data Assimilation with Multiple Assimilation Systems Using WaveWatch III v5.16 and SWAN v41.20
Authors: Li Jiangyu , Zhang Shaoqing
Published: October 2019

Abstract. High-quality wave prediction with a numerical wave model is of societal value. To initialize the wave model, wave data assimilation (WDA) is necessary to combine the model and observations. Due to imperfect numerical schemes and approximated physical processes, a wave model is always biased in relation to the real world. In this study, two assimilation systems are first developed using two nearly independent wave models; then, “perfect” and “biased” assimilation frameworks based on the two assimilation systems are designed to reveal the uncertainties of WDA. A series of “biased” assimilation experiments is conducted to systematically examine the adverse impact of model bias on WDA. A statistical approach based on the results from multiple assimilation systems is explored to carry out bias correction, by which the final wave analysis is significantly improved with the merits of individual assimilation systems. The framework with multiple assimilation systems provides an effective platform to improve wave analyses and predictions and help identify model deficits, thereby improving the model.