bluuebunny/crossref_metadata_2025 huggingface dataset:
Cloud Security Threats and Techniques to Strengthen Cloud Computing Adoption Framework
Authors: Khan Nabeel , Al-Yasiri Adil
Published: August 2016

Cloud Computing allows firms to outsource their entire information technology (IT) process, allowing them to concentrate more on their core business to enhance their productivity and innovation in offering services to customers. It allows businesses to cut down heavy cost incurred over IT infrastructure without losing focus on customer needs. However, to a certain limit adopting Cloud computing has struggled to grow among many established and growing organizations due to several security and privacy related issues. Throughout the course of this study several interviews were conducted, with cloud developers and security experts, and the literature was reviewed. This study enabled us to understand, current and future, security and privacy challenges with cloud computing by providing suitable solutions to identified challenges. The outcome of this study led to identification of total 18, current and future, security issues affecting several attributes of cloud computing. In this process of identification, the author also found mitigation techniques to avert these security issues. A security guide is formulated which enables organizations to be aware of security challenges, vulnerabilities and techniques to evade them.
Particle Swarm Optimization Algorithm as a Tool for Profile Optimization
Authors: Klepac Goran
Published: August 2016

Complex analytical environment is challenging environment for finding customer profiles. In situation where predictive model exists like Bayesian networks challenge became even bigger regarding combinatory explosion. Complex analytical environment can be caused by multiple modality of output variable, fact that each node of Bayesian network can potetnitaly be target variable for profiling, as well as from big data environment, which cause data complexity in way of data quantity. As an illustration of presented concept particle swarm optimization algorithm will be used as a tool, which will find profiles from developed predictive model of Bayesian network. This paper will show how partical swarm optimization algorithm can be powerfull tool for finding optimal customer profiles given target conditions as evidences within Bayesian networks.
Relative susceptibility of sunflower maintainer lines and resistance sources to natural infestations of the banded sunflower moth (Lepidoptera: Tortricidae)
Authors: Prasifka Jarrad R. , Hulke Brent S.
Published: August 2016

The banded sunflower moth, Cochylis hospes Walsingham (Lepidoptera: Tortricidae), is a significant seed-feeding pest of sunflowers (Helianthus Linnaeus; Asteraceae) in North America. Though some wild Helianthus, interspecific crosses, and H. annuus Linnaeus cultivars (which precede hybrid sunflower breeding) have low susceptibility to banded sunflower moth, no apparent effort has been made to evaluate modern inbred lines as a source of resistance for hybrids. In field trials from 2013 to 2015, inbred maintainer (HA) lines, resistant accessions (PI), and unreleased, partially inbred (F6) lines were evaluated in field trials using natural infestations of banded sunflower moth. Results show greater seed damage to maintainer lines than the other groups, but also significant variability among lines within groups. The best maintainer, HA 207, had ≈75% fewer damaged seed than the most susceptible HA lines. Among the resistant PI and unreleased inbred lines, only one entry had significantly less damage than HA 207. While PI 494859 showed banded moth resistance superior to the best inbred lines, its other agronomic liabilities make breeding with the least susceptible maintainer lines appear more practical. A key unknown for any attempts to breed hybrids resistant to banded sunflower moth is how closely damage is correlated between inbred lines and their hybrids.
Nestin-Expressing Precursors Give Rise to Both Endothelial as well as Nonendothelial Lymph Node Stromal Cells
Authors: Koning Jasper J. , Konijn Tanja , Lakeman Kim A. , O’Toole Tom , Kenswil Keane J. G. , Raaijmakers Marc H. G. P. , Michurina Tatyana V. , Enikolopov Grigori , Mebius Reina E.
Published: August 2016

During embryogenesis, lymph nodes form through intimate interaction between lymphoid tissue inducer and lymphoid tissue organizer (LTo) cells. Shortly after birth in mice, specialized stromal cell subsets arise that organize microenvironments within the lymph nodes; however, their direct precursors have not yet been identified. In the bone marrow, mesenchymal stem cells are labeled with GFP in nestin-GFP mice, and we show that during all stages of development, nestin+ cells are present within lymph nodes of these mice. At day of birth, both mesenchymal CD31− and endothelial CD31+ LTo cells were GFP+, and only the population of CD31− LTo cells contained mesenchymal precursors. These CD31−nestin+ cells are found in the T and B cell zones or in close association with high endothelial venules in adult lymph nodes. Fate mapping of nestin+ cells unambiguously revealed the contribution of nestin+ precursor cells to the mesenchymal as well as the endothelial stromal populations within lymph nodes. However, postnatal tamoxifen induced targeting of nestin+ cells in nes-creER mice showed that most endothelial cells and only a minority of the nonendothelial cells were labeled. Overall our data show that nestin+ cells contribute to all subsets of the complex stromal populations that can be found in lymph nodes.
Allergen-Induced IL-6 Regulates IL-9/IL-17A Balance in CD4+ T Cells in Allergic Airway Inflammation
Authors: Schütze Nicole , Trojandt Stefanie , Kuhn Stephanie , Tomm Janina M. , von Bergen Martin , Simon Jan C. , Polte Tobias
Published: August 2016

IL-9–secreting Th9 cells have been considered to play a pivotal role in the pathogenesis of atopic diseases. To what extent IL-9–producing cells are induced or regulated by sensitization with naturally occurring allergens is not yet clear. Naturally occurring allergens are capable of inducing IL-6 production in dendritic cells (DCs). Whether allergen-induced IL-6 supports a Th9 subtype by increasing IL-9 production, as observed in in vitro studies, or rather favors Th17 differentiation is not finally resolved. Therefore, in the present study we have investigated the impact of IL-6 on the Th9/Th17 balance depending on the predominant cytokine milieu and, additionally, in vivo using a DC-driven murine asthma model. In vitro, IL-6 increases Th9 cells under strong IL-4 and TGF-β activation, whereas under moderate IL-4 and TGF-β activation the presence of IL-6 shifts naive CD4+ cells to Th17 cells. To induce allergic airway inflammation, OVA-pulsed DCs from IL-6–deficient or wild-type donors were adoptively transferred into BALB/c mice. Recipients receiving IL-6–producing wild-type DCs showed a significant decrease of Th9- and IL-4–producing Th2 cells but an increase of Th17 cells in lung tissue in comparison with recipients sensitized with IL-6–deficient DCs. Our data suggest that the IL-6–mediated reduction of Th2-related IL-4 leads to a decline of the Th9 immune response and allows Th17 differentiation.
The Tetraspanin TSPAN33 Controls TLR-Triggered Macrophage Activation through Modulation of NOTCH Signaling
Authors: Ruiz-García Almudena , López-López Susana , García-Ramírez José Javier , Baladrón Victoriano , Ruiz-Hidalgo María José , López-Sanz Laura , Ballesteros Ángela , Laborda Jorge , Monsalve Eva María , Díaz-Guerra María José M.
Published: August 2016

The involvement of NOTCH signaling in macrophage activation by Toll receptors has been clearly established, but the factors and pathways controlling NOTCH signaling during this process have not been completely delineated yet. We have characterized the role of TSPAN33, a tetraspanin implicated in a disintegrin and metalloproteinase (ADAM) 10 maturation, during macrophage proinflammatory activation. Tspan33 expression increases in response to TLR signaling, including responses triggered by TLR4, TLR3, and TLR2 activation, and it is enhanced by IFN-γ. In this study, we report that induction of Tspan33 expression by TLR and IFN-γ is largely dependent on NOTCH signaling, as its expression is clearly diminished in macrophages lacking Notch1 and Notch2 expression, but it is enhanced after overexpression of a constitutively active intracellular domain of NOTCH1. TSPAN33 is the member of the TspanC8 tetraspanin subgroup more intensely induced during macrophage activation, and its overexpression increases ADAM10, but not ADAM17, maturation. TSPAN33 favors NOTCH processing at the membrane by modulating ADAM10 and/or Presenilin1 activity, thus increasing NOTCH signaling in activated macrophages. Moreover, TSPAN33 modulates TLR-induced proinflammatory gene expression, at least in part, by increasing NF-κB–dependent transcriptional activity. Our results suggest that TSPAN33 represents a new control element in the development of inflammation by macrophages that could constitute a potential therapeutic target.
The ATM Kinase Restrains Joining of Both VDJ Signal and Coding Ends
Authors: Meek Katheryn , Xu Yao , Bailie Caleb , Yu Kefei , Neal Jessica A.
Published: August 2016

The evidence that ATM affects resolution of RAG-induced DNA double-strand breaks is profuse and unequivocal; moreover, it is clear that the RAG complex itself cooperates (in an undetermined way) with ATM to facilitate repair of these double-strand breaks by the classical nonhomologous end-joining pathway. The mechanistic basis for the cooperation between ATM and the RAG complex has not been defined, although proposed models invoke ATM and RAG2’s C terminus in maintaining the RAG postcleavage complex. In this study, we show that ATM reduces the rate of both coding and signal joining in a robust episomal assay; we suggest that this is the result of increased stability of the postcleavage complex. ATM’s ability to inhibit VDJ joining requires its enzymatic activity. The noncore C termini of both RAG1 and RAG2 are also required for ATM’s capacity to limit signal (but not coding) joining. Moreover, potential phosphorylation targets within the C terminus of RAG2 are also required for ATM’s capacity to limit signal joining. These data suggest a model whereby the RAG signal end complex is stabilized by phosphorylation of RAG2 by ATM.
The Cascadia subduction zone and related subduction systems - seismic structure, intraslab earthquakes and processes, and earthquake hazards
Authors: Kirby S , Wang K , Dunlop S
Published: August 2016

The following report is the principal product of an international workshop titled "Intraslab Earthquakes in the Cascadia Subduction System: Science and Hazards" and was sponsored by the U.S. Geological Survey, the Geological Survey of Canada and the University of
Victoria. This meeting was held at the University of Victoria's Dunsmuir Lodge, Vancouver Island, British Columbia, Canada on September 18 - 21, 2000 and brought 46 participants from the U.S., Canada, Latin America and Japan. This gathering was organized to bring together active research
investigators in the science of subduction and intraslab earthquake hazards. Special emphasis was given to "warm-slab" subduction systems, i.e., those systems involving young oceanic lithosphere subducting at moderate to slow rates, such as the Cascadia system in the U.S. and Canada, and the Nankai
system in Japan. All the speakers and poster presenters provided abstracts of their presentations that were a made available in an abstract volume at the workshop. Most of the authors subsequently provided full articles or extended abstracts for this volume on the topics that they discussed at the
workshop. Where updated versions were not provided, the original workshop abstracts have been included. By organizing this workshop and assembling this volume, our aim is to provide a global perspective on the science of warm-slab subduction, to thereby advance our understanding of internal slab
processes and to use this understanding to improve appraisals of the hazards associated with large intraslab earthquakes in the Cascadia system. These events have been the most frequent and damaging earthquakes in western Washington State over the last century. As if to underscore this fact, just
six months after this workshop was held, the magnitude 6.8 Nisqually earthquake occurred on February 28th, 2001 at a depth of about 55 km in the Juan de Fuca slab beneath the southern Puget Sound region of western Washington. The Governor's Office of the State of Washington estimated damage at more
than US$2 billion, making it among the costliest earthquakes in U.S. history.
Effect of the infection with the nematode Haemonchus contortus (Strongylida: Trichostrongylidae) on the haematological, biochemical, clinical and reproductive traits in rams
Authors: Rouatbi Mariem , Gharbi Mohamed , Rjeibi Mohamed R. , Ben Salem Imen , Akkari Hafidh , Lassoued Narjess , Rekik Mourad
Published: August 2016

This study aimed to investigate the effect of Haemonchus contortus infection on rams’ haematological, biochemical and clinical parameters and reproductive performances. A total number of 12 Barbarine rams (control and infected) were included in the experiment. The infected group received 30 000 H. contortus third-stage larvae orally. Each ram’s ejaculate was immediately evaluated for volume, sperm cell concentration and mortality rate. At the end of the experiment (day 82 post-infection), which lasted 89 days, serial blood samples were collected in order to assess plasma testosterone and luteinising hormone (LH) concentrations. There was an effect of time, infection and their interaction on haematological parameters (p < 0.001). In infected rams, haematocrit, red blood cell count and haemoglobin started to decrease from 21 days post-infection. There was an effect of time and infection for albumin. For total protein, only infection had a statistically significant effect. For glucose, only time had a statistically significant effect. Concentrations were significantly lower in infected rams compared to control animals. A significant effect of infection and time on sperm concentrations and sperm mortality was observed. The effect of infection appears in time for sperm concentrations at days 69 and 76 post-infection. Sperm mortality rate was significantly higher in infected animals at day 46 post-infection when compared to control group (p < 0.05). Finally, plasma testosterone traits (average concentration, cumulated levels during the sampling period and pulse frequency) were depressed in infected rams when compared to control counterparts; none of these endocrine traits were affected for plasma LH.
Cellular immune responses induced in vitro by Ehrlichia ruminantium secreted proteins and identification of vaccine candidate peptides
Authors: Thema Nontobeko , Pretorius Alri , Tshilwane Selaelo I. , Liebenberg Junita , Steyn Helena , Van Kleef Mirinda
Published: August 2016

Secreted proteins are reported to induce cell-mediated immunity characterised by the production of interferon-gamma (IFN)-γ. In this study three open reading frames (ORFs) (Erum8060, Erum7760, Erum5000) encoding secreted proteins were selected from the Ehrlichia ruminantium (Welgevonden) genome sequence using bioinformatics tools to determine whether they induce a cellular immune response in vitro with mononuclear cells from needle and tick infected animals. The whole recombinant protein of the three ORFs as well as four adjacent fragments of the Erum5000 protein (Erum5000A, Erum5000B, Erum5000C, Erum5000D) were successfully expressed in a bacterial expression system which was confirmed by immunoblots using anti-His antibodies and sheep sera. These recombinant proteins were assayed with immune sheep and cattle peripheral blood mononuclear cells (PBMCs), spleen and lymph node (LN) cells to determine whether they induce recall cellular immune responses in vitro. Significant proliferative responses and IFN-γ production were evident for all recombinant proteins, especially Erum5000A, in both ruminant species tested. Thus overlapping peptides spanning Erum5000A were synthesised and peptides that induce proliferation of memory CD4+ and CD8+ T cells and production of IFN-γ were identified. These results illustrate that a Th1 type immune response was elicited and these recombinant proteins and peptides may therefore be promising candidates for development of a heartwater vaccine.
The future of digital medicine in the aging society
Authors: Wortley David
Published: August 2016

David Wortley is CEO and Founder of Gamification and Enabling Technologies Strategic Solutions (www.gaetss.com), a consultancy on the strategic use of Gamification and Enabling Technologies for the transformation of business and society. He is a recognized authority on the practical application of Gamification and Enabling Technologies to address global challenges in areas such as health, environment, and education. He is a serial technology innovator and has been a pioneer of emerging technologies for over 30 years. He is an expert advisor to the European Union and an accredited business mentor. His specialist expertise is in the commercialization of disruptive digital technologies. David is also a Founding Council Member of the International Society of Digital Medicine (ISDM).

David was the Founding Director of the Serious Games Institute (SGI) www.seriousgamesinstitute.co.uk at Coventry University and he was responsible for the development of the institute as a global thought leader on the application of immersive technologies (which include video games, virtual worlds, and social networking) to serious social and economic issues such as education, simulation, health, commerce, and climate change. Working with academics, regional development agencies, and leading computer games companies, David made the SGI is a focal point for games-based learning, simulation, and immersive three-dimensional (3D) virtual environments and an engine for innovation and social and economic regeneration. David is a respected (see http://davidwortley.com/testimonials.html) and sought-after international conference speaker and writer for global publications on Learning Technologies, Defence and Health applications. He has written numerous papers on technology and society (see http://www.davidwortley.com/articles.html), and he is a regular conference presenter (see www.davidwortley.com/conferences.html)
Air Pollution and Emergency Department Visits for Depression: A Multicity Case-Crossover Study
Authors: Szyszkowicz Mieczysław , Kousha Termeh , Kingsbury Mila , Colman Ian
Published: August 2016

Background

The aim of this study was to investigate the associations between ambient air pollution and emergency department (ED) visits for depression.

Methods

Health data were retrieved from the National Ambulatory Care Reporting System. ED visits for depression were retrieved from the National Ambulatory Care Reporting System using the International Classification of Diseases (ICD-10), Tenth revision codes; ICD-10: F32 (mild depressive episode) and ICD-10: F33 (recurrent depressive disorder). A case-crossover design was employed for this study. Conditional logistic regression models were used to estimate odds ratios.

Results

For females, exposure to ozone was associated with increased risk of an ED visit for depression between 1 and 7 days after exposure, for males, between 1 and 5, and 8 days after exposure, with odds ratios ranging between 1.02 and 1.03.

Conclusions

These findings suggest that, as hypothesized, there is a positive association between exposure to air pollution and ED visits for depression.
Integrated Stress Response Signaling Pathways Induced by Supraphysiological Concentrations of Thyroid Hormone Inhibit Viral Replication
Authors: Ishaq Mohammad , Natarajan Ven
Published: August 2016

Supraphysiological concentrations (SPCs) of triiodo-L-thyronine (T3) have been used in the treatment of a number of nonviral diseases. However, the signaling mechanisms that regulate the function of T3 at these concentrations and their role in modulating cellular stress pathways and antiviral responses are unknown. Here, we have investigated the effects of SPCs of T3 on integrated stress response (ISR) signaling pathways and the replication of vesicular stomatitis virus (VSV). T3 amplified Poly IC-induced activation of RNA-dependent protein kinase, induced phosphorylation of eIF2α, stress granule (SG) formation, IRE1α phosphorylation, XBP1 splicing, and the expression of stress markers. T3 inhibited VSV replication by modulating SG formation and the expression of stress response markers. ISR activator guanabenz also inhibited VSV replication and amplified T3-induced anti-VSV response. To summarize, we have uncovered novel functions of T3 at SPCs as an activator of ISR signaling pathways and an inhibitor of VSV replication. This study offers a proof of principle of the concept that ISR activating agents like SPC of T3 and guanabenz can be potential antiviral agents.
Scrub Typhus in Northeastern Thailand: Eschar Distribution, Abnormal Electrocardiographic Findings, and Predictors of Fatal Outcome
Authors: Thipmontree Wilawan , Tantibhedhyangkul Wiwit , Silpasakorn Saowaluk , Wongsawat Ekkarat , Waywa Duangdao , Suputtamongkol Yupin
Published: August 2016

Scrub typhus is endemic in Thailand. Of the 495 patients with acute undifferentiated fever studied in Maharat Nakhon Ratchasima Hospital, Nakhon Ratchasima, Thailand, from June 1, 2011, to December 31, 2012, 146 patients (29.5%) had confirmed scrub typhus. The majority of cases were male, farmers, with the mean (±standard deviation) age of 54.1 ± 15.2 years. A total of 59 patients (40.4%) had eschar lesion. The commonest sites for an eschar in male patients were the perineum, inguinal, and buttock area; whereas in females, it was the head and neck area. Abnormal electrocardiogram was found in 39 of 79 patients (49.4%) with sinus tachycardia being the most frequent finding (17, 21.5%). A total of 73 patients (50%) had at least one complication. Myocarditis was the cause of complete heart block in a scrub typhus patient, and he fully recovered after receiving intravenous chloramphenicol treatment. The case fatality rate was 6.2% (nine deaths).The independent predictors for fatal outcome were age over 65 years (odds ratio [OR] = 14.49, 95% confidence interval [CI] = 1.26–166.44, P = 0.03), acute kidney injury (OR = 12.75, 95% CI = 1.77–92.07, P = 0.01), and hyperbilirubinemia (OR = 24.82, 95% CI = 2.12–286.61, P = 0.01). Early diagnosis and prompt appropriate treatment can improve the patient's outcome.
Human Helminths and Allergic Disease: The Hygiene Hypothesis and Beyond
Authors: Santiago Helton C. , Nutman Thomas B.
Published: August 2016

There is much debate about the interaction between helminths and allergic disease. The “Hygiene Hypothesis,” a very popular concept among scientists and the lay public, states that infections, especially during childhood, can protect against allergic diseases. Indeed, helminth infections are known to induce regulatory responses in the host that can help the control of inflammation (including allergic inflammation). However, these infections also induce type-2-associated immune responses including helminth-specific IgE that can cross-react against environmental allergens and mediate IgE-driven effector responses. Thus, it is the delicate balance between the parasites' anti- and pro-allergenic effects that define the helminth/allergy interface.
Treatment of Schistosomiasis in a Patient Allergic to Praziquantel: A Desensitization and Treatment Protocol
Authors: Patel Trupti A. , Lukawska Joanna , Rowe Jennifer , Bailey Robin L.
Published: August 2016

Praziquantel is the mainstay of treatment of Schistosomiasis, which affects at least 262 million people worldwide. It is also used in the treatment of other trematode as well as cestode infections, with few safe and effective alternatives. It is generally well tolerated and allergic reactions are rare. In this report, we present a case of schistosomiasis with a history of a hypersensitivity reaction to praziquantel. Skin-prick and intradermal testing were performed, followed by treatment through rapid desensitization. This protocol may be of value to those patients requiring praziquantel treatment with a history of IgE-mediated allergy to the drug.
Artemisinin Resistance–Associated K13 Polymorphisms of Plasmodium falciparum in Southern Rwanda, 2010–2015
Authors: Tacoli Costanza , Gai Prabhanjan P. , Bayingana Claude , Sifft Kevin , Geus Dominik , Ndoli Jules , Sendegeya Augustin , Gahutu Jean Bosco , Mockenhaupt Frank P.
Published: August 2016

Emerging artemisinin resistance is a threat to global malaria control. Mutations in the Plasmodium falciparum Kelch 13 (K13) propeller domain confer artemisinin resistance and constitute molecular markers for its detection and monitoring. We sequenced 222 P. falciparum isolates obtained from community children in the Huye District of southern Rwanda in 2010, 2014, and 2015 to investigate the presence of K13 polymorphisms. No polymorphisms were observed in 2010 but they were present in 2.5% and 4.5% in 2014 and 2015, respectively. In 2015, two isolates showed candidate K13 resistance mutations (P574L and A675V), which are common in southeast Asia and associated with delayed parasite clearance. K13 polymorphisms in southern Rwanda are infrequent but include variants associated with artemisinin resistance. Establishing correlations with local treatment response and in vitro resistance assays are needed in addition to further monitoring K13 polymorphisms in the study area.
Simulations of sulfate–nitrate–ammonium (SNA) aerosols during the extreme
haze events over northern China in October 2014
Authors: Chen Dan , Liu Zhiquan , Fast Jerome , Ban Junmei
Published: August 2016

Abstract. Extreme haze events have occurred frequently over China in recent years. Although many studies have investigated the formation mechanisms associated with PM2.5 for heavily polluted regions in China based on observational data, adequately predicting peak PM2.5 concentrations is still challenging for regional air quality models. In this study, we evaluate the performance of one configuration of the Weather Research and Forecasting model coupled with chemistry (WRF-Chem) and use the model to investigate the sensitivity of heterogeneous reactions on simulated peak sulfate, nitrate, and ammonium concentrations in the vicinity of Beijing during four extreme haze episodes in October 2014 over the North China Plain. The highest observed PM2.5 concentration of 469 µg m−3 occurred in Beijing. Comparisons with observations show that the model reproduced the temporal variability in PM2.5 with the highest PM2.5 values on polluted days (defined as days in which observed PM2.5 is greater than 75 µg m−3), but predictions of sulfate, nitrate, and ammonium were too low on days with the highest observed concentrations. Observational data indicate that the sulfur/nitric oxidation rates are strongly correlated with relative humidity during periods of peak PM2.5; however, the model failed to reproduce the highest PM2.5 concentrations due to missing heterogeneous/aqueous reactions. As the parameterizations of those heterogeneous reactions are not well established yet, estimates of SO2-to-H2SO4 and NO2/NO3-to-HNO3 reaction rates that depend on relative humidity were applied, which improved the simulation of sulfate, nitrate, and ammonium enhancement on polluted days in terms of both concentrations and partitioning among those species. Sensitivity simulations showed that the extremely high heterogeneous reaction rates and also higher emission rates than those reported in the emission inventory were likely important factors contributing to those peak PM2.5 concentrations.
20 years of ClO measurements in the Antarctic lower stratosphere
Authors: Nedoluha Gerald E. , Connor Brian J. , Mooney Thomas , Barrett James W. , Parrish Alan , Gomez R. Michael , Boyd Ian , Allen Douglas R. , Kotkamp Michael , Kremser Stefanie , Deshler Terry , Newman Paul , Santee Michelle L.
Published: August 2016

Abstract. We present 20 years (1996–2015) of austral springtime measurements of chlorine monoxide (ClO) over Antarctica from the Chlorine Oxide Experiment (ChlOE1) ground-based millimeter wave spectrometer at Scott Base, Antarctica, as well 12 years (2004–2015) of ClO measurements from the Aura Microwave Limb Sounder (MLS). From August onwards we observe a strong increase in lower stratospheric ClO, with a peak column amount usually occurring in early September. From mid-September onwards we observe a strong decrease in ClO. In order to study interannual differences, we focus on a 3-week period from 28 August to 17 September for each year and compare the average column ClO anomalies. These column ClO anomalies are shown to be highly correlated with the average ozone mass deficit for September and October of each year. We also show that anomalies in column ClO are strongly anti-correlated with 30 hPa temperature anomalies, both on a daily and an interannual timescale. Making use of this anti-correlation we calculate the linear dependence of the interannual variations in column ClO on interannual variations in temperature. By making use of this relationship, we can better estimate the underlying trend in the total chlorine (Cly  =  HCl + ClONO2 + HOCl + 2  ×  Cl2 + 2  ×  Cl2O2 + ClO + Cl). The resultant trends in Cly, which determine the long-term trend in ClO, are estimated to be −0.5 ± 0.2, −1.4 ± 0.9, and −0.6 ± 0.4 % year−1, for zonal MLS, Scott Base MLS (both 2004–2015), and ChlOE (1996–2015) respectively. These trends are within 1σ of trends in stratospheric Cly previously found at other latitudes. The decrease in ClO is consistent with the trend expected from regulations enacted under the Montreal Protocol.
Chemical cycling and deposition of atmospheric mercury in polar regions:
review of recent measurements and comparison with models
Authors: Angot Hélène , Dastoor Ashu , De Simone Francesco , Gårdfeldt Katarina , Gencarelli Christian N. , Hedgecock Ian M. , Langer Sarka , Magand Olivier , Mastromonaco Michelle N. , Nordstrøm Claus , Pfaffhuber Katrine A. , Pirrone Nicola , Ryjkov Andrei , Selin Noelle E. , Skov Henrik , Song Shaojie , Sprovieri Francesca , Steffen Alexandra , Toyota Kenjiro , Travnikov Oleg , Yang Xin , Dommergue Aurélien
Published: August 2016

Abstract. Mercury (Hg) is a worldwide contaminant that can cause adverse health effects to wildlife and humans. While atmospheric modeling traces the link from emissions to deposition of Hg onto environmental surfaces, large uncertainties arise from our incomplete understanding of atmospheric processes (oxidation pathways, deposition, and re-emission). Atmospheric Hg reactivity is exacerbated in high latitudes and there is still much to be learned from polar regions in terms of atmospheric processes. This paper provides a synthesis of the atmospheric Hg monitoring data available in recent years (2011–2015) in the Arctic and in Antarctica along with a comparison of these observations with numerical simulations using four cutting-edge global models. The cycle of atmospheric Hg in the Arctic and in Antarctica presents both similarities and differences. Coastal sites in the two regions are both influenced by springtime atmospheric Hg depletion events and by summertime snowpack re-emission and oceanic evasion of Hg. The cycle of atmospheric Hg differs between the two regions primarily because of their different geography. While Arctic sites are significantly influenced by northern hemispheric Hg emissions especially in winter, coastal Antarctic sites are significantly influenced by the reactivity observed on the East Antarctic ice sheet due to katabatic winds. Based on the comparison of multi-model simulations with observations, this paper discusses whether the processes that affect atmospheric Hg seasonality and interannual variability are appropriately represented in the models and identifies research gaps in our understanding of the atmospheric Hg cycling in high latitudes.
Influence of Rain on the Abundance and Size Distribution of Bioaerosols
Authors: Rathnayake Chathurika M. , Metwali Nervana , Jayarathne Thilina , Kettler Josh , Huang Yuefan , Thorne Peter S. , O'Shaughnessy Patrick T. , Stone Elizabeth A.
Published: August 2016

Abstract. Assessing the environmental, health and climate impacts of bioaerosols requires knowledge of their size and abundance. These two properties were assessed through daily measurements of chemical tracers for pollens (sucrose, fructose, and glucose), fungal spores (mannitol and glucans) and Gram-negative bacterial endotoxins in fine particulate matter (PM2.5), coarse PM (PM10–2.5) and PM10 (as the combination of PM2.5 and PM10–2.5) during the spring tree pollen season (mid-April to early-May) and late summer ragweed season (late-August to early-September) in the Midwestern US in 2013. Under dry conditions, pollen and fungal spore tracers were primarily in coarse PM (˃ 75 %), as expected for particles greater than 2.5 µm. Rainfall on May 2 corresponded to maximum atmospheric pollen tracer levels and a redistribution of pollen tracers to the fine PM fraction (˃ 80 %). Both changes were attributed to the osmotic rupture of pollen grains that led to the suspension of fine-sized pollen fragments. Fungal spore tracers peaked in concentration following spring rain events and decreased in particle size, but to a lesser extent than pollens. A short, heavy thunderstorm in late summer corresponded to an increase in endotoxin and glucose levels, with a simultaneous shift to smaller particle sizes. Simultaneous increases in bioaerosol levels and decrease in their size has significant implications for population exposures to bioaerosols, particularly during rain events. Chemical mass balance (CMB) source apportionment modelling and regionally-specific pollen profiles were used to apportion PM mass to pollens and fungal spores. Springtime pollen contributions to PM10 mass ranged from 0.04–0.8 µg m−3 (0.2–38 %, averaging 4 %), with maxima occurring on rainy days. Fungal spore contributions to PM10 mass ranged from 0.1–1.5 µg m−3 (0.8–17 %, averaging 5 %), with maxima occurring after rain. Overall, this study defines changes to size distributions and concentrations of pollens, fungal spores, and endotoxins in response to rain in the Midwestern United States and advances the ability to apportion PM mass to pollens.
Can models robustly represent aerosol–convection interactions if their cloud microphysics is uncertain?
Authors: White Bethan , Gryspeerdt Edward , Stier Philip , Morrison Hugh , Thompson Gregory
Published: August 2016

Abstract. This study investigates the hydrometeor development and response to cloud droplet number concentration (CDNC) perturbations in convection-permitting model configurations. We present results from a real-data simulation of deep convection in the Congo basin, an idealised supercell case, and a warm-rain large-eddy simulation (LES). In each case we compare two frequently used double-moment bulk microphysics schemes and investigate the response to CDNC perturbations. In the Congo basin simulations both microphysics schemes have large positive biases in surface precipitation, frequency of high radar reflectivities and frequency of cold cloud compared to observations. In all cases, differences in the simulated cloud morphology and precipitation are found to be significantly greater between the microphysics schemes than due to CDNC perturbations within each scheme. Further, we show that the response of the hydrometeors to CDNC perturbations strongly differs not just between microphysics schemes but also between different cases of convection. Sensitivity tests show that the representation of autoconversion is the dominant factor that drives differences in rain production between the microphysics schemes in the idealised precipitating shallow cumulus case and in a sub-region of the Congo basin simulations dominated by liquid-phase processes. In this region, rain mass is also shown to be relatively insensitive to the radiative effects of an overlying layer of ice-phase cloud. In the idealised supercell case, thermodynamic impacts on the storm system using different microphysics parameterisations can equal those due to aerosol effects. These results highlight the large uncertainty in cloud and precipitation responses to aerosol in convection-permitting simulations and have important implications not just for modelling studies of aerosol-convection interaction. These results indicate the continuing need for tighter observational constraints of cloud processes and response to aerosol in a range of meteorological regimes.
Estimates of Mode-S EHS aircraft-derived wind observation errors using triple collocation
Authors: de Haan Siebren
Published: August 2016

Abstract. Information on the accuracy of meteorological observation is essential to assess the applicability of the measurements. In general, accuracy information is difficult to obtain in operational situations, since the truth is unknown. One method to determine this accuracy is by comparison with the model equivalent of the observation. The advantage of this method is that all measured parameters can be evaluated, from 2 m temperature observation to satellite radiances. The drawback is that these comparisons also contain the (unknown) model error. By applying the so-called triple-collocation method (Stoffelen, 1998), on two independent observations at the same location in space and time, combined with model output, and assuming uncorrelated observations, the three error variances can be estimated. This method is applied in this study to estimate wind observation errors from aircraft, obtained utilizing information from air traffic control surveillance radar with Selective Mode Enhanced Surveillance capabilities (Mode-S EHS, see de Haan, 2011). Radial wind measurements from Doppler weather radar and wind vector measurements from sodar, together with equivalents from a non-hydrostatic numerical weather prediction model, are used to assess the accuracy of the Mode-S EHS wind observations. The Mode-S EHS wind (zonal and meridional) observation error is estimated to be less than 1.4±0.1 m s−1 near the surface and around 1.1 ± 0.3 m s−1 at 500 hPa.
Coupling sky images with radiative transfer models: a new method to estimate
cloud optical depth
Authors: Mejia Felipe A. , Kurtz Ben , Murray Keenan , Hinkelman Laura M. , Sengupta Manajit , Xie Yu , Kleissl Jan
Published: August 2016

Abstract. A method for retrieving cloud optical depth (τc) using a UCSD developed ground-based sky imager (USI) is presented. The radiance red–blue ratio (RRBR) method is motivated from the analysis of simulated images of various τc produced by a radiative transfer model (RTM). From these images the basic parameters affecting the radiance and red–blue ratio (RBR) of a pixel are identified as the solar zenith angle (θ0), τc, solar pixel angle/scattering angle (ϑs), and pixel zenith angle/view angle (ϑz). The effects of these parameters are described and the functions for radiance, Iλτc, θ0, ϑs, ϑz, and RBRτc, θ0, ϑs, ϑz are retrieved from the RTM results. RBR, which is commonly used for cloud detection in sky images, provides non-unique solutions for τc, where RBR increases with τc up to about τc = 1 (depending on other parameters) and then decreases. Therefore, the RRBR algorithm uses the measured Iλmeasϑs, ϑz, in addition to RBRmeasϑs, ϑz, to obtain a unique solution for τc. The RRBR method is applied to images of liquid water clouds taken by a USI at the Oklahoma Atmospheric Radiation Measurement (ARM) program site over the course of 220 days and compared against measurements from a microwave radiometer (MWR) and output from the Min et al. (2003) method for overcast skies. τc values ranged from 0 to 80 with values over 80, being capped and registered as 80. A τc RMSE of 2.5 between the Min et al. (2003) method and the USI are observed. The MWR and USI  have an RMSE of 2.2, which is well within the uncertainty of the MWR. The procedure developed here provides a foundation to test and develop other cloud detection algorithms.
Martian magnetism with orbiting sub-millimeter sensor: Simulated
retrieval system
Authors: Larsson Richard , Milz Mathias , Eriksson Patrick , Mendrok Jana , Kasai Yasuko , Buehler Stefan Alexander , Diéval Catherine , Brain David , Hartogh Paul
Published: August 2016

Abstract. A Mars-orbiting sub-millimeter sensor can be used to retrieve the magnetic field at low altitudes over large areas of significant planetary crustal magnetism of the surface of Mars from measurements of circularly polarized radiation emitted by the 368 GHz ground-state molecular oxygen absorption line. We design a full retrieval system for one example orbit to show the expected accuracies on the magnetic field components that one realization of such a Mars satellite mission could achieve. We find that the two horizontal components of the magnetic field can be measured at about 200 nT accuracy, globally, with a vertical resolution of about 4 km from about 6 km up to 70 km in tangent altitude. The method and some of its potential pitfalls are described and discussed.
Tuning without over-tuning: parametric uncertainty quantification for the NEMO ocean model
Authors: Williamson Daniel , Blaker Adam T. , Sinha Bablu
Published: August 2016

Abstract. In this paper we discuss climate model tuning and present an iterative automatic tuning method from the statistical science literature. The method, which we refer to here as iterative refocussing (though also known as history matching), avoids many of the common pitfalls of automatic tuning procedures that are based on optimisation of a cost function; principally the over-tuning of a climate model due to using only partial observations. This avoidance comes by seeking to rule out parameter choices that we are confident could not reproduce the observations, rather than seeking the model that is closest to them (a procedure that risks over-tuning). We comment on the state of climate model tuning and illustrate our approach through 3 waves of iterative refocussing of the NEMO ORCA2 global ocean model run at 2° resolution. We show how at certain depths the anomalies of global mean temperature and salinity in a standard configuration of the model exceeds 10 standard deviations away from observations and show the extent to which this can be alleviated by iterative refocussing without compromising model performance spatially. We show how model improvements can be achieved by simultaneously perturbing multiple parameters, and illustrate the potential of using low resolution ensembles to tune NEMO ORCA configurations at higher resolutions.
Experimental study on retardation of a heavy NAPL vapor in
partially saturated porous media
Authors: Kleinknecht Simon M. , Class Holger , Braun Jürgen
Published: August 2016

Abstract. NAPL contaminants introduced into the unsaturated zone spread as a liquid phase; however, they can also vaporize and migrate in a gaseous state. Heavy vapors preferentially migrate downward due to their greater density and, thus, pose a potential threat to underlying aquifers. Large-scale column experiments were performed to quantify partitioning processes responsible for the retardation of carbon disulfide (CS2) vapor in partially saturated porous media. The results were compared with a theoretical approach taking into account the partitioning into the aqueous phase. The experiments were conducted in large, vertical columns (i.d. = 0.109 m) of 2 m length packed with different porous media. A slug of CS2 vapor and the conservative tracer argon was injected at the bottom of the column followed by a nitrogen chase. Different seepage velocities were applied to characterize the transport and to evaluate their impact on retardation. Concentrations of CS2 and argon were measured at the top outlet of the column using two gas chromatographs. The temporal-moment analysis for step input was employed to evaluate concentration breakthrough curves and to quantify diffusion/dispersion and retardation. The experiments conducted showed a pronounced retardation of CS2 in moist porous media as a function of porous medium and water saturation. An increase in the retardation coefficient with increasing water saturation was observed. Thus, the novel vapor-retardation experiments demonstrated that migrating CS2 vapor is retarded as a result of partitioning into the aqueous phase. Moreover, CS2 which is dissolved in the pore water is amenable to biodegradation. First evidence of CS2 decay by biodegradation was found in the experiments. The findings contribute to the understanding of vapor plume transport in the unsaturated zone and provides valuable experimental data for the transfer to field like conditions.
PREFACE
Authors: Toth Charles K.
Published: August 2016

No abstract available.
MONITORING AIRCRAFT MOTION AT AIRPORTS BY LIDAR
Authors: Toth C. , Jozkow G. , Koppanyi Z. , Young S. , Grejner-Brzezinska D.
Published: August 2016

Improving sensor performance, combined with better affordability, provides better object space observability, resulting in new applications. Remote sensing systems are primarily concerned with acquiring data of the static components of our environment, such as the topographic surface of the earth, transportation infrastructure, city models, etc. Observing the dynamic component of the object space is still rather rare in the geospatial application field; vehicle extraction and traffic flow monitoring are a few examples of using remote sensing to detect and model moving objects. Deploying a network of inexpensive LiDAR sensors along taxiways and runways can provide both geometrically and temporally rich geospatial data that aircraft body can be extracted from the point cloud, and then, based on consecutive point clouds motion parameters can be estimated. Acquiring accurate aircraft trajectory data is essential to improve aviation safety at airports. This paper reports about the initial experiences obtained by using a network of four Velodyne VLP- 16 sensors to acquire data along a runway segment.
COOPERATIVE UAS LOCALIZATION USING LOWCOST SENSORS
Authors: Goel Salil , Kealy Allison , Lohani Bharat
Published: August 2016

Networks of small, low cost Unmanned Aerial Systems (UASs) have the potential to improve responsiveness and situational awareness across an increasing number of applications including defense, surveillance, mapping, search and rescue, disaster management, mineral exploration, assisted guidance and navigation etc. These ad hoc UAS networks typically have the capability to communicate with each other and can share data between the individual UAS nodes. Thus these networks can operate as robust and efficient information acquisition platforms. For any of the applications involving UASs, a primary requirement is the localization i.e. determining the position and orientation of the UAS. The performance requirements of localization can vary with individual applications, for example: mapping applications need much higher localization accuracy as compared to the applications involving only surveillance. The sharing of appropriate data between UASs can prove to be advantageous when compared to a single UAS, in terms of improving the positioning accuracy and reliability particularly in partially or completely GNSS denied environments. This research aims to integrate low cost positioning sensors and cooperative localization technique for a network of UASs. Our hypothesis is that it is possible to achieve high accurate, real-time localization of each of the nodes in the network even with cheaper sensors if the nodes of the network share information among themselves. This hypothesis is validated using simulations and the results are analyzed both for centralized and distributed estimation architectures. At first, the results are studied for a two node network which is then expanded for a network containing more number of nodes. Having more nodes in the network allows us to study the properties of the network including the effect of size and shape of the network on accuracy of the nodes.