bluuebunny/crossref_metadata_2025 huggingface dataset:
In vitro evaluation of temperature rise during different post space preparations
Authors: Gokturk Hakan , Ozkocak Ismail , Taskan Mehmet Murat , Aytac Fatma , Karaarslan Emine Sirin
Published: April 2016

Objective: The aim of this study was to evaluate temperature alterations on the outer root surface during post space preparation with six different post drills by using an infrared thermometer. Materials and Methods: Sixty extracted single-rooted human mandibular incisor teeth were used. After root canal obturation, the specimens were divided into six groups (n = 10). During post space preparation, the temperature rises were measured in the middle third of the roots using a noncontact infrared thermometer with a sensitivity of 0.1°C. The temperature data were transferred from the thermometer to the computer and were observed graphically. Results: The maximum temperature rise was observed in Snowpost 2 (29.95 ± 10.2°C) (P < 0.001), but there were no significant differences among Snowpost 2 (29.95 ± 10.2°C), Snowpost 1 (24.6 ± 8.0°C), and Relyx 2 (17.68 ± 9.1°C) (P > 0.05). Conclusions: Although water coolant used, the critical temperature rise was observed on the outer root surface in all post drill systems.
In vitro antimicrobial evaluation of toothpastes with natural compounds
Authors: Smolarek Priscila de Camargo , Esmerino Luis Antonio , Chibinski Ana Cláudia , Bortoluzzi Marcelo Carlos , dos Santos Elizabete Brasil , Junior Vitoldo Antonio Kozlowski
Published: April 2016

Objectives: This in vitro study evaluated the antimicrobial effects of commercial toothpastes containing natural compounds. Materials and Methods: The study groups were divided based on the natural compound present in the toothpaste composition: Sorbitol (I), tocopherol (II), mint (III), cinnamon/mint (IV), propolis/melaleuca (V), mint/açai (VI), mint/guarana (VII), propolis (VIII), negative control (IX), and the positive control (X). The antimicrobial properties of the toothpastes were tested using the disk diffusion method against oral pathogens: Streptococcus mutans, Pseudomonas aeruginosa, and Enterococcus faecalis. The resulting inhibition halos were measured in millimeters. Results: The data indicated that the bacteria responded differently to the toothpastes (P < 0.0001). The diameters of the inhibition halos against S. mutans were in decreasing order of efficacy: Propolis/melaleuca > mint/guarana > mint/açai > sorbitol > tocopherol > cinnamon/mint > propolis > mint (P < 0.001 vs. negative control). E. faecalis showed variable responses to the dentifrices in the following order of decreasing efficacy: Mint/guarana > propolis > sorbitol > mint/açai > tocopherol > cinnamon/mint > mint = propolis/melaleuca = negative control. The product with the highest antimicrobial activity was mint/guarana, which was significantly different than propolis/melaleuca, mint, cinnamon/mint, and tocopherol and negative control (P < 0.001). The statistical analysis indicated that propolis, sorbitol, and mint/açai did not show any differences compared to mint/guarana (P > 0.05) and positive control (P > 0.05). P. aeruginosa was resistant to all dental gels tested including positive control. Conclusion: The toothpastes with natural compounds have therapeutic potential and need more detailed searches for the correct clinic therapeutic application. The results from this study revealed differences in the antimicrobial activities of commercial toothpastes with natural compounds.
Dentinal crack formation during root canal preparations by the twisted file adaptive, Reciproc and WaveOne instruments
Authors: Gergi Richard M. , Osta Nada E. , Naaman Alfred S.
Published: April 2016

Objective: This study aimed to compare the frequency of dentinal microcracks after root canal shaping with 2 reciprocating (Reciproc and WaveOne) and 1 combined continuous reciprocating motion twisted files adaptive (TFA) rotary system. Materials and Methods: Ninety molars were chosen and divided into three groups of 30 each. Root canal preparation was achieved by using Reciproc R25, Primary WaveOne and TFA systems. All the roots were horizontally sectioned at 15, 9, and 3 mm from the apex. The slices were then viewed each under a microscope at × 25 magnification to determine the presence of cracks. The absence/presence of cracks was recorded, and the data were analyzed with a Chi-square test. The significance level was set at P < 0.05. Results: Instrumentation with Reciproc produced significantly more complete cracks than WaveOne and TFA (P = 0.032). The TFA system produced significantly less cracks then the Reciproc and WaveOne systems apically (P = 0.004). Conclusions: Within the limits of this study, the TFA system caused less cracks then the full reciprocating system (Reciproc and WaveOne). Single-file reciprocating files produced significantly more incomplete dentinal cracks than full-sequence adaptive rotary motion.
Hardness and modulus of elasticity of primary and permanent teeth after wear against different dental materials
Authors: Galo Rodrigo , Contente Marta Maria Martins Giamatei , Galafassi Daniel , Borsatto Maria Cristina
Published: April 2016

Objectives: The purpose of this study was to determine the Young's modulus and the hardness of deciduous and permanent teeth following wear challenges using different dental materials. Materials and Methods: Wear challenges were performed against four dental materials: A resin-based fissure sealant (Fluoroshield®), a glass ionomer based fissure sealant (Vitremer®), and two microhybrid composite resins (Filtek Z250 and P90®). Using the pin-on-plate design, a deciduous or a permanent tooth was made into a pin (4 mm × 4 mm × 2 mm) working at a 3 N vertical load, 1 Hz frequency, and 900 cycles (15 min) with Fusayama artificial saliva as a lubricant. Before and after the tribological tests, the hardness and elasticity modulus of the tooth samples were measured by creating a nanoindentation at load forces up to 50 mN and 150 mN. All of the results were statistically analyzed using ANOVA and post-hoc Duncan's tests (P < 0.05). Results: No difference in hardness was encountered between deciduous and permanent teeth (P < 0.05) or modulus of elasticity (P < 0.05) before or after the wear challenges for all of the dental materials tested. Conclusions: Wear challenges against the studied dental materials did not alter the properties of permanent or deciduous teeth after the application of a 3 N load.
Effectiveness of audiovisual distraction eyewear and computerized delivery of anesthesia during pulp therapy of primary molars in phobic child patients
Authors: Fakhruddin Kausar Sadia , Hisham El Batawi , Gorduysus Mehmet Omer
Published: April 2016

Objectives: The aim of this study is to assess the effectiveness of audiovisual distraction technique with video eyewear and computerized delivery system-intrasulcular (CDS-IS) during the application of local anesthetic in phobic pediatric patients undergoing pulp therapy of primary molars. Materials and Methods: This randomized, crossover clinical study includes 60 children, aged between 4 and 7-year-old (31 boys and 29 girls). Children were randomly distributed equally into two groups as A and B. This study involved two treatment sessions of pulp therapy, 1-week apart. During treatment session I, group A had an audiovisual distraction with video eyewear, whereas group B had audiovisual distraction using projector display only without video eyewear. During treatment session II, group A had undergone pulp therapy without video eyewear distraction, whereas group B had the pulp treatment using video eyewear distraction. Each session involved the pulp therapy of equivalent teeth in the opposite sides of the mouth. At each visit scores on the Modified Child Dental Anxiety Scale (MCDAS) (f) were used to evaluate the level of anxiety before treatment. After the procedure, children were instructed to rate their pain during treatment on the Wong Bakers’ faces pain scale. Changes in pulse oximeter and heart rate were recorded in every 10 min. Results: From preoperative treatment session I (with video eyewear) to preoperative treatment session II (without video eyewear) for the MCDAS (f), a significant (P > 0.03) change in the mean anxiety score was observed for group A. Self-reported mean pain score decreases dramatically after treatment sessions’ with video eyewear for both groups. Conclusion: The use of audiovisual distraction with video eyewear and the use of CDS-IS system for anesthetic delivery was demonstrated to be effective in improving children's cooperation, than routine psychological interventions and is, therefore, highly recommended as an effective behavior management technique for long invasive procedures of pulp therapy in young children.
Biomarkers and Targeted Therapy in Pancreatic Cancer
Authors: Karandish Fataneh , Mallik Sanku
Published: April 2016

Pancreatic ductal adenocarcinoma (PDAC) constitutes 90% of pancreatic cancers. PDAC is a complex and devastating disease with only 1%–3% survival rate in five years after the second stage. Treatment of PDAC is complicated due to the tumor microenvironment, changing cell behaviors to the mesenchymal type, altered drug delivery, and drug resistance. Considering that pancreatic cancer shows early invasion and metastasis, critical research is needed to explore different aspects of the disease, such as elaboration of biomarkers, specific signaling pathways, and gene aberration. In this review, we highlight the biomarkers, the fundamental signaling pathways, and their importance in targeted drug delivery for pancreatic cancers.
Positively curved manifolds with large spherical rank
Authors: Schmidt Benjamin , Shankar Krishnan , Spatzier Ralf
Published: April 2016

Rigidity results are obtained for Riemannian

d

-manifolds with

\sec \geq 1

and spherical rank at least

d - 2 > 0

. Conjecturally, all such manifolds are locally isometric to a round sphere or complex projective space with the (symmetric) Fubini–Study metric. This conjecture is verified in all odd dimensions, for metrics on

d

-spheres when

d \neq 6

, for Riemannian manifolds satisfying the Rakić duality principle, and for Kählerian manifolds.
On the strong orderability of overtwisted 3–folds
Authors: Casals Roger , Presas Francisco
Published: April 2016

In this article we address the existence of positive loops of contactomorphisms in overtwisted contact 3–folds. We present a construction of such positive loops in the contact fibered connected sum of certain contact 3–folds along transverse knots. In particular, we obtain positive loops of contactomorphisms in a class of overtwisted contact structures.
Los nuevos movimientos sociales, el uso de las TIC y su impacto social
Authors: Flores Morador Fernando , Cortés Vásquez Judith
Published: April 2016

El siguiente trabajo es el resultado una revisión sobre los Nuevos movimientos sociales  y  el uso de las nuevas tecnologías, vistos a la luz de la filosofía política. Esta reflexión parte de los resultados obtenidos en la tesis doctoral sobre “Nuevos movimientos sociales y uso de las TIC. Estudio de casos” presentada en la Universidad Complutense de Madrid en el doctorado de Comunicación, Cambio Social y Desarrollo. Si bien estos movimientos han existido desde hace mucho tiempo, las nuevas tecnologías digitales permiten la visualización, expansión y divulgación mayor de sus agendas y propuestas. El “saber hacer” de estos nuevos movimientos y su capacidad de transformación social, son expresión de un marco de estrategias diferentes a las propuestas por los grupos tradicionales enmarcados en los partidos políticos. Las metodologías de acción civil requieren de un flujo natural de la información, que los partidos políticos no pueden reproducir. Los recursos simbólicos y las expresiones de sentimientos y emociones, saltan a la palestra del juego social configurando un nuevo lenguaje, una manera distinta de ser. Más allá de la implicaciones mediáticas y políticas, hay un trasfondo en términos de cambio social profundo.
Co-circulation of Plasmodium and Bacterial DNAs in Blood of Febrile and Afebrile Children from Urban and Rural Areas in Gabon
Authors: Mourembou Gaël , Nzondo Sydney Maghendji , Ndjoyi-Mbiguino Angélique , Lekana-Douki Jean Bernard , Kouna Lady Charlène , Matsiegui Pierre Blaise , Manego Rella Zoleko , Moukandja Irene Pegha , Keïta Alpha Kabinet , Tissot-Dupont Hervé , Fenollar Florence , Raoult Didier
Published: April 2016

Malaria is considered to be the most common etiology of fever in sub-Saharan Africa while bacteremias exist but are under assessed. This study aimed to assess bacteremias and malaria in children from urban and rural areas in Gabon. DNA extracts from blood samples of 410 febrile and 60 afebrile children were analyzed using quantitative polymerase chain reaction. Plasmodium spp. was the microorganism most frequently detected in febrile (78.8%, 323/410) and afebrile (13.3%, 8/60) children, (P < 0.001). DNA from one or several bacteria were detected in 15 febrile patients (3.7%) but not in the controls (P = 0.1). This DNA was more frequently detected as co-infections among febrile children tested positive for Plasmodium (4.6%, 15/323) than in those tested negative for Plasmodium (0%, 0/87; P = 0.04). The bacteria detected were Streptococcus pneumoniae 2.4% (10/410), Staphylococcus aureus 1.7% (7/410), Salmonella spp. 0.7% (3/410), Streptococcus pyogenes 0.2% (1/410) and Tropheryma whipplei 0.2% (1/410) only in febrile children. Coxiella burnetii, Borrelia spp., Bartonella spp., Leptospira spp., and Mycobacterium tuberculosis were not observed. This paper reports the first detection of bacteremia related to T. whipplei in Gabon and shows that malaria decreases in urban areas but not in rural areas. Co-infections in febrile patients are common, highlighting the need to improve fever management strategies in Gabon.
The Impact of a School-Based Water, Sanitation, and Hygiene Program on Absenteeism, Diarrhea, and Respiratory Infection: A Matched–Control Trial in Mali
Authors: Trinies Victoria , Garn Joshua V. , Chang Howard H. , Freeman Matthew C.
Published: April 2016

We conducted a matched–control trial in Mali to assess the effectiveness of a comprehensive school-based water, sanitation, and hygiene (WASH) intervention on pupil absence, diarrhea, and respiratory infections. After completion of the intervention, data were collected from 100 beneficiary schools and 100 matched comparison schools in 5–6 sessions over a 14-month period. Data collection included roll calls to assess absenteeism and interviews with a subset of pupils to assess recent absence and disease symptoms. The odds of pupils being absent at roll call were 23% higher in beneficiary schools than in comparison schools (odds ratio [OR]: 1.23, 95% confidence interval [CI]: 1.06, 1.42). The odds of pupils reporting being absent due to diarrhea (OR: 0.73, 95% CI: 0.56, 0.94) or having had diarrhea (OR: 0.71, 95% CI: 0.60, 0.85) or respiratory infection symptoms (OR: 0.75, 95% CI: 0.65, 0.86) in the past week were lower in beneficiary schools compared with comparison schools. We found that a school-based WASH intervention can have a positive effect on reducing rates of illness, as well as absence due to diarrhea. However, we did not find evidence that these health impacts led to a reduction in overall absence. Higher absence rates are less likely attributable to the intervention than the result of an imbalance in unobserved confounders between study groups.
Seasonal Distribution and Climatic Correlates of Dengue Disease in Dhaka, Bangladesh
Authors: Morales Ivonne , Salje Henrik , Saha Samir , Gurley Emily S.
Published: April 2016

Dengue has been regularly reported in Dhaka, Bangladesh, since a large outbreak in 2000. However, to date, we have limited information on the seasonal distribution of dengue disease and how case distribution correlates with climate. Here, we analyzed dengue cases detected at a private diagnostic facility in Dhaka during 2010–2014. We calculated Pearson cross-correlation coefficients to examine the relationship between the timing of cases and both rainfall and temperature. There were 2,334 cases diagnosed during the study period with 76% over the age of 15 years. Cases were reported in every month of the study; however, 90% of cases occurred between June and November. Increases in rainfall were correlated with increases in cases 2 months later (correlation of 0.7). The large proportion of adult cases is consistent with substantial population susceptibility and suggests Dhaka remains at risk for outbreaks. Although cases occurred year-round, public health preparedness should be focused during peak months.
Juvenile Nasopharyngeal Angiofibroma: Correlating Histology, Surgical Approach and Blood Loss
Authors: Aiyer RG , Gupta Rahul R , Jagtap Prarthna J , Thapar Tanuj
Published: April 2016

Juvenile nasopharyngeal angiofibroma (JNA) is locally destructive benign vascular tumor for which surgical excision has always been the treatment of choice, in spite of the availability of various other treatment modalities. Complete removal at the maiden attempt has always been the key to a successful outcome. Recurrences (or rather residuals) discourage both the surgeon and patient.

This prospective study was carried out in the Department of Otorhinolaryngology, Sir Sayajirao General Hospital, Vadodara, Gujarat, between August 2002 and 2015. We have studied 28 patients with JNA for growth patterns, histological characteristics and to compare various surgical modalities. Besides other investigations a detailed histological examination of the tumor was performed which suggested that as the tumor ages, the stroma predominates and the vessels are compressed into slits. In actively growing tumor the vascular component predominates. The percentage of open vascular channels is directly proportional to the bleeding while the intervascular fibrosis is inversely related. Surgical excision of JNA is the preferred modality of treatment. Surgical approach is sometimes the most tricky decision. Choosing the right approach is akin to walking on the thin rope with adequate exposure on one side and postoperative scar on the other.

How to cite this article

Thapar T, Gupta RR, Jagtap PJ, Aiyer RG. Juvenile Nasopharyngeal Angiofibroma: Correlating Histology, Surgical Approach and Blood Loss. Clin Rhinol An Int J 2015;8(2):47-52.
Bilateral Inverted Papilloma: A Rare Rhinological Pathology
Authors: Subramaniam Thavakumar , Shamis Ayham , Barghouthi Taleb , Patil Naishadh
Published: April 2016

Inverted papilloma is a benign tumor occurring in the head and neck. A large proportion of reported cases are unilateral, however, in rare instances bilateral disease is seen. This may lead to misdiagnosis.

How to cite this article

Subramaniam T, Shamis A, Barghouthi T, Patil N. Bilateral Inverted Papilloma: A Rare Rhinological Pathology. Clin Rhinol An Int J 2015;8(2):58-59.
Comparison between Endoscopic Septoplasty and Conventional Septoplasty: Our Experience
Authors: Tukaram Kandakure Vinod
Published: April 2016

Introduction

Nasal obstruction due to deviated nasal septum is a common problem encountered by otolaryngologists. A variety of surgical procedures have been tried in the treatment of the same.

Objective

This study was conducted to evaluate the outcomes and complications of endoscopic and conventional septoplasty.

Materials and methods

This is a prospective, randomized study done in Government Medical College, Latur in which 52 patients with symptomatic deviated nasal septum were included in the study. Eighteen of them underwent conventional septoplasty and the rest had endoscopic septoplasty.

Results

The difference in the functional outcome of both the surgeries was insignificant. Endoscopic septoplasty had better outcome with respect to complications and proved as an easier method to correct posterior deviations and isolated spurs.

Conclusion

Endoscopic septoplasty allows accurate, conservative repair of obstructive nasal septum deviations, with fewer complications and better functional results compared to conventional septoplasty.

How to cite this article

Tukaram KV, Lahane VJ, Mishra S, Prakash NP. Comparison between Endoscopic Septoplasty and Conventional Septoplasty: Our Experience. Clin Rhinol An Int J 2015;8(3):93-98.
Bilateral Total Aplasia of Paranasal Sinuses: A Rare Case Report
Authors: Joshi Ankita , Sundarray Chinmay , Sahoo Krishna Arpita
Published: April 2016

Paranasal sinus anatomical anomalies with unknown etiology are common. Paranasal sinus-related diseases are associated with so high rate of morbidities, it becomes essential to identify the structure and pathophysiology of the paranasal sinuses. Computed tomography (CT) is a valuable tool in displaying its anatomy, any anatomic variations and diseases. As paranasal sinus development is a complex and long-lasting process, there are great structural variations between individuals. Maxillary and/or frontal sinus aplasia or hypoplasia are more common than the other types. Several degrees and combinations of aplasias and hypoplasias have been reported; however, there is only two case of total paranasal sinus aplasia in the literature. Here, we present the third case of total paranasal sinus aplasia, and the first ever case reported from India.

How to cite this article

Joshi A, Sundarray C, Sahoo KA. Bilateral Total Aplasia of Paranasal Sinuses: A Rare Case Report. Clin Rhinol An Int J 2015;8(3):124-126.
Combination of Neutral Zone and Flange Techniques during Fabrication of Complete Dentures for a segmental Mandibulectomy patient with restricted Mouth Opening
Authors: Kulkarni Rahul S , Pawar Ravindra S
Published: April 2016

Oral malignancies originating from or secondarily involving mandible are usually treated by surgical excision and may result in mandibular defect with or without loss of continuity. Surgical resection may lead to loss of buccal and lingual sulci, loss of symmetry of mandibular function, altered mandibular movements and deviation of the residual fragment toward the resected side. Radiation therapy is often given after resection of malignant tumors, which may produce undesirable side effects, like mucositis and mucosal atrophy, trismus, increased susceptibility to irritation and ulceration and reduction in salivary flow. This overall change in anatomy and physiology of oral cavity after segmental mandibular resection presents a restorative challange. This clinical report presents fabrication of complete dentures for a patient who had undergone segmental mandibulectomy and had restricted mouth opening.

How to cite this article

Kulkarni RS, Pawar RS. Combination of Neutral Zone and Flange Techniques during Fabrication of Complete Dentures for a Segmental Mandibulectomy Patient with Restricted Mouth Opening. Int J Prosthodont Restor Dent 2015;5(4):114-117.
The effect of different levels of diet total volatile nitrogen on performance, carcass characteristics and meat total volatile nitrogen in broiler chickens
Authors: Fallah Farhad , Ebrahimnezhad Yahya , Maheri-Sis Naser , Ghasemi-Sadabadi Mohammad
Published: April 2016

Abstract. This study was conducted to determine the effect of different levels of diet total volatile nitrogen (TVN) on performance, carcass characteristics and meat TVN in broiler chickens. A total of 400 one-day-old Ross 308 broiler chicks was used in this study. On the first day, male and female chicks were separated by feather sexing. In the first week, all chicks were reared together and fed with a basal diet without urea. At the beginning of the second week, the male and female chicks were weighed so that the average body weight of chicks was approximately equal in each cage. Then the male and female chicks were allocated to 25 floor pens in a completely randomized design with five treatments, five replicates and 16 chicks in each replicate (eight males and eight females) throughout the experimental period, which lasted for 42 days. Dietary treatments consisted of zero (control), 0.5, 1, 1.5 and 2 % of urea in the diets. Before starting the experiment, the TVN levels in all diets were measured after adding different levels of urea, and TVN levels were 13.30, 14.95, 17.26, 23.26 and 27.47 mg 100 g−1 and 16.66, 15.02, 17.81, 24.66 and 26.25 mg 100 g−1 in starter and grower diets, respectively. Feed intake (FI), body weight gain (BWG) and the feed conversion ratio (FCR) were measured. Carcass characteristics as well as TVN in breast meat, thigh meat and the whole carcass and in left tibia and toe ash were measured. The results showed that FI levels were significantly different between the groups at different weeks except for the second week (P < 0.05). The BWG significantly differed among treatments (P < 0.05). In the second and sixth weeks, FCR was affected by increasing TVN in the diet (P < 0.05). Increasing TVN in broiler diets had a significant effect on the carcass characteristics (P < 0.05). Increasing TVN to more than 15 mg 100 g−1 linearly reduced left tibia and toe ash (P < 0.05). In addition, increasing TVN in the broiler diets affected the TVN of breast meat, thigh meat and the whole carcass of broilers (P < 0.05). These results suggest that increasing diet TVN to more than 15 mg 100 g−1 reduces performance traits, carcass characteristics, and left tibia and toe ash and increases the TVN amount of breast meat, thigh meat and the whole carcass.
Seasonal characterization of submicron aerosol chemical composition and organic aerosol sources in the southeastern United States: Atlanta, Georgia,and Look Rock, Tennessee
Authors: Budisulistiorini Sri Hapsari , Baumann Karsten , Edgerton Eric S. , Bairai Solomon T. , Mueller Stephen , Shaw Stephanie L. , Knipping Eladio M. , Gold Avram , Surratt Jason D.
Published: April 2016

Abstract. A year-long near-real-time characterization of non-refractory submicron aerosol (NR-PM1) was conducted at an urban (Atlanta, Georgia, in 2012) and rural (Look Rock, Tennessee, in 2013) site in the southeastern US using the Aerodyne Aerosol Chemical Speciation Monitor (ACSM) collocated with established air-monitoring network measurements. Seasonal variations in organic aerosol (OA) and inorganic aerosol species are attributed to meteorological conditions as well as anthropogenic and biogenic emissions in this region. The highest concentrations of NR-PM1 were observed during winter and fall seasons at the urban site and during spring and summer at the rural site. Across all seasons and at both sites, NR-PM1 was composed largely of OA (up to 76 %) and sulfate (up to 31 %). Six distinct OA sources were resolved by positive matrix factorization applied to the ACSM organic mass spectral data collected from the two sites over the 1 year of near-continuous measurements at each site: hydrocarbon-like OA (HOA), biomass burning OA (BBOA), semi-volatile oxygenated OA (SV-OOA), low-volatility oxygenated OA (LV-OOA), isoprene-derived epoxydiols (IEPOX) OA (IEPOX-OA) and 91Fac (a factor dominated by a distinct ion at m∕z 91 fragment ion previously observed in biogenic influenced areas). LV-OOA was observed throughout the year at both sites and contributed up to 66 % of total OA mass. HOA was observed during the entire year only at the urban site (on average 21 % of OA mass). BBOA (15–33 % of OA mass) was observed during winter and fall, likely dominated by local residential wood burning emission. Although SV-OOA contributes quite significantly ( ∼  27 %), it was observed only at the urban site during colder seasons. IEPOX-OA was a major component (27–41 %) of OA at both sites, particularly in spring and summer. An ion fragment at m∕z 75 is well correlated with the m∕z 82 ion associated with the aerosol mass spectrum of IEPOX-derived secondary organic aerosol (SOA). The contribution of 91Fac to the total OA mass was significant (on average 22 % of OA mass) at the rural site only during warmer months. Comparison of 91Fac OA time series with SOA tracers measured from filter samples collected at Look Rock suggests that isoprene oxidation through a pathway other than IEPOX SOA chemistry may contribute to its formation. Other biogenic sources could also contribute to 91Fac, but there remains a need to resolve the exact source of this factor based on its significant contribution to rural OA mass.
Biogenic, anthropogenic and sea salt sulfate size-segregated aerosols in the Arctic summer
Authors: Ghahreman Roya , Norman Ann-Lise , Abbatt Jonathan P. D. , Levasseur Maurice , Thomas Jennie L.
Published: April 2016

Abstract. Size-segregated aerosol sulfate concentrations were measured on board the Canadian Coast Guard Ship (CCGS) Amundsen in the Arctic during July 2014. The objective of this study was to utilize the isotopic composition of sulfate to address the contribution of anthropogenic and biogenic sources of aerosols to the growth of the different aerosol size fractions in the Arctic atmosphere. Non-sea-salt sulfate is divided into biogenic and anthropogenic sulfate using stable isotope apportionment techniques. A considerable amount of the average sulfate concentration in the fine aerosols with a diameter  <  0.49 µm was from biogenic sources (>  63 %), which is higher than in previous Arctic studies measuring above the ocean during fall (<  15 %) (Rempillo et al., 2011) and total aerosol sulfate at higher latitudes at Alert in summer (>  30 %) (Norman et al., 1999). The anthropogenic sulfate concentration was less than that of biogenic sulfate, with potential sources being long-range transport and, more locally, the Amundsen's emissions. Despite attempts to minimize the influence of ship stack emissions, evidence from larger-sized particles demonstrates a contribution from local pollution. A comparison of δ34S values for SO2 and fine aerosols was used to show that gas-to-particle conversion likely occurred during most sampling periods. δ34S values for SO2 and fine aerosols were similar, suggesting the same source for SO2 and aerosol sulfate, except for two samples with a relatively high anthropogenic fraction in particles  <  0.49 µm in diameter (15–17 and 17–19 July). The high biogenic fraction of sulfate fine aerosol and similar isotope ratio values of these particles and SO2 emphasize the role of marine organisms (e.g., phytoplankton, algae, bacteria) in the formation of fine particles above the Arctic Ocean during the productive summer months.
The effect of viscosity on the HO2 uptake by sucrose and secondary organic aerosol particles
Authors: Lakey Pascale S. J. , Berkemeier Thomas , Krapf Manuel , Dommen Josef , Steimer Sarah S. , Whalley Lisa K. , Ingham Trevor , Baeza-Romero Maria T. , Pöschl Ulrich , Shiraiwa Manabu , Ammann Markus , Heard Dwayne E.
Published: April 2016

Abstract. We report the first measurements of HO2 uptake coefficients, γ, for secondary organic aerosol particles (SOA) and for the well-studied model compound sucrose which was doped with copper. Above 65 % relative humidity (RH), γ for copper doped sucrose aerosol particles equalled the surface mass accommodation coefficient α = 0.22 ± 0.06 but decreased to γ = 0.012 ± 0.007 upon decreasing the RH to 17 %. The trend of γ with RH can be explained by an increase in aerosol viscosity, as demonstrated using the kinetic multi-layer model of aerosol surface and bulk chemistry (KM-SUB). SOA from two different precursors, α-pinene and 1,3,5- trimethylbenzene (TMB), was investigated, yielding small uptake coefficients of γ < 0.001 and γ = 0.004 ± 0.002, respectively. It is postulated that the larger values measured for TMB derived SOA compared to α-pinene derived SOA are either due to differing viscosity, a different liquid water content of the aerosol particles or a HO2 + RO2 reaction occurring within the aerosol particles.
Representativeness of Total Column Water Vapour Retrievals from Instruments on Polar Orbiting Satellites
Authors: Diedrich Hannes , Wittchen Falco , Preusker René , Fischer Jürgen
Published: April 2016

Abstract. The remote sensing of Total Column Water Vapour (TCWV) from polar orbiting, sun-synchronous satellite spectrometers such as the Medium Resolution Imaging Spectrometer (MERIS) on board of ENVISAT and the Moderate Imaging Spectroradiometer (MODIS) on board of Aqua and Terra enables observations on a high spatial resolution and a high accuracy over land surfaces. The observations serve studies about small scale variations of water vapour as well as the detection of local and global trends. However, depending on the swath width of the sensor, the temporal sampling is low and the observations of TCWV are limited to cloud-free land scenes. This study quantifies the representativeness of a single TCWV observation at the time of the satellite overpass under cloud-free conditions by investigating the diurnal cycle of TCWV using 9 years of a 2-hourly TCWV data set from global GNSS (Global Navigation Satellite Systems) stations. It turns out, that the TCWV observed at 10:30 local time (LT) is generally lower than the daily mean TCWV by 0.65 mm (4 %) on average for cloud-free cases. Averaging over all GNSS stations, the monthly mean TCWV at 10:30 LT, constrained to cases that are cloud-free, is by 5 mm (25 %) lower than the monthly mean TCWV at 10:30 LT of all cases. Additionally, the diurnal variability of TCWV is assessed. For the majority of GNSS stations, the amplitude of the averaged diurnal cycle ranges between 1 % and 5 % of the daily mean with a minimum between 6 LT and 10 LT and maximum between 16 LT and 20 LT. However, a high variability of TCWV on an individual day is detected. On average, the TCWV varies by 15 % around the daily mean.
Twenty-first century wave climate projections for Ireland and surface winds in the North Atlantic Ocean
Authors: Gallagher Sarah , Gleeson Emily , Tiron Roxana , McGrath Ray , Dias Frédéric
Published: April 2016

Abstract. Ireland has a highly energetic wave and wind climate, and is therefore uniquely placed in terms of its ocean renewable energy resource. The socio-economic importance of the marine resource to Ireland makes it critical to quantify how the wave and wind climate may change in the future due to global climate change. Projected changes in winds, ocean waves and the frequency and severity of extreme weather events should be carefully assessed for long-term marine and coastal planning. We derived an ensemble of future wave climate projections for Ireland using the EC-Earth global climate model and the WAVEWATCH III® wave model, by comparing the future 30-year period 2070–2099 to the period 1980–2009 for the RCP4.5 and the RCP8.5 forcing scenarios. This dataset is currently the highest resolution wave projection dataset available for Ireland. The EC-Earth ensemble predicts decreases in mean (up to 2 % for RCP4.5 and up to 3.5 % for RCP8.5) 10 m wind speeds over the North Atlantic Ocean (5–75° N, 0–80° W) by the end of the century, which will consequently affect swell generation for the Irish wave climate. The WAVEWATCH III® model predicts an overall decrease in annual and seasonal mean significant wave heights around Ireland, with the largest decreases in summer (up to 15 %) and winter (up to 10 %) for RCP8.5. Projected decreases in mean significant wave heights for spring and autumn were found to be small for both forcing scenarios (less than 5 %), with no significant decrease found for RCP4.5 off the west coast in those seasons.
Differential responses of seabirds to environmental variability over 2 years in the continental shelf and oceanic habitats of southeastern Bering Sea
Authors: Yamamoto Takashi , Kokubun Nobuo , Kikuchi Dale M. , Sato Nobuhiko , Takahashi Akinori , Will Alexis P. , Kitaysky Alexander S. , Watanuki Yutaka
Published: April 2016

Abstract. Seasonal sea-ice cover has been decreasing in the southeastern Bering Sea shelf, which might affect ecosystem dynamics and availability of food resources to marine top predators breeding in the region. In this study, we investigated the foraging responses of two seabird species, surface-foraging red-legged kittiwakes Rissa brevirostris (hereafter, RLKI) and pursuit-diving foraging thick-billed murres Uria lomvia (TBMU) to different marine environmental conditions over 2 years. At-sea distributions of RLKI and TBMU breeding on St. George Island, the largest seabird colony in the region, were recorded using GPS loggers, and blood samples were taken to examine their physiological condition and isotopic foraging niche in a given year. Between the study years, winter ice retreated earlier and summer water temperatures were relatively warmer in 2014 compared to those in 2013. RLKI foraging occurred mostly over the oceanic basin in both years. TBMU, however, foraged mostly over the shelf but showed a relatively higher use of the shelf break and oceanic basin in 2013. The foraging distances from the colony peaked at 250–300 km in 2013 and bimodally at 150–250 and 300–350 km in 2014 for RLKI and tended to be farther in 2013 compared to those in 2014 for TBMU. Plasma levels of corticosterone did not differ between the years in RLKI but differed in TBMU, showing higher levels of physiological stress incurred by murres in 2013, the year of relatively cooler sea surface temperatures with later sea-ice retreat. δ13N (a proxy of trophic level of prey) did not differ between the years in either RLKI or TBMU. These results suggest that the response of ecosystem dynamics to climate variability in the southeastern Bering Sea may differ between the ocean basin and continental shelf regions, which, in turn, may generate differential responses in seabirds relying on those habitats for foraging.
Local artifacts in ice core methane records caused by layered bubble trapping and in situ production: a multi-site investigation
Authors: Rhodes Rachael H. , Faïn Xavier , Brook Edward J. , McConnell Joseph R. , Maselli Olivia J. , Sigl Michael , Edwards Jon , Buizert Christo , Blunier Thomas , Chappellaz Jérôme , Freitag Johannes
Published: April 2016

Abstract. Advances in trace gas analysis allow localised, non-atmospheric features to be resolved in ice cores, superimposed on the coherent atmospheric signal. These high-frequency signals could not have survived the low-pass filter effect that gas diffusion in the firn exerts on the atmospheric history and therefore do not result from changes in the atmospheric composition at the ice sheet surface. Using continuous methane (CH4) records obtained from five polar ice cores, we characterise these non-atmospheric signals and explore their origin. Isolated samples, enriched in CH4 in the Tunu13 (Greenland) record are linked to the presence of melt layers. Melting can enrich the methane concentration due to a solubility effect, but we find that an additional in situ process is required to generate the full magnitude of these anomalies. Furthermore, in all the ice cores studied there is evidence of reproducible, decimetre-scale CH4 variability. Through a series of tests, we demonstrate that this is an artifact of layered bubble trapping in a heterogeneous-density firn column; we use the term “trapping signal” for this phenomenon. The peak-to-peak amplitude of the trapping signal is typically 5 ppb, but may exceed 40 ppb. Signal magnitude increases with atmospheric CH4 growth rate and seasonal density contrast, and decreases with accumulation rate. Significant annual periodicity is present in the CH4 variability of two Greenland ice cores, suggesting that layered gas trapping at these sites is controlled by regular, seasonal variations in the physical properties of the firn. Future analytical campaigns should anticipate high-frequency artifacts at high-melt ice core sites or during time periods with high atmospheric CH4 growth rate in order to avoid misinterpretation of such features as past changes in atmospheric composition.
Greenland warming during the last interglacial: the relative importance of insolation and oceanic changes
Authors: Pedersen Rasmus A. , Langen Peter L. , Vinther Bo M.
Published: April 2016

Abstract. Insolation changes during the Eemian (the last interglacial period, 129–116 000 years before present) resulted in warmer than present conditions in the Arctic region. The NEEM ice core record suggests warming of 8±4 K in northwestern Greenland based on water stable isotopes. Here we use general circulation model experiments to investigate the causes of the Eemian warming in Greenland. Simulations of the atmospheric response to combinations of Eemian insolation and pre-industrial oceanic conditions and vice versa, are used to disentangle the impacts of the insolation change and the related changes in sea surface temperatures and sea ice conditions. The changed oceanic conditions cause warming throughout the year, prolonging the impact of the summertime insolation increase. Consequently, the oceanic conditions cause annual mean warming of 2 K at the NEEM site, whereas the insolation alone causes an insignificant change. Taking the precipitation changes into account, however, the insolation and oceanic changes cause more comparable increases in the precipitation-weighted temperature, implying that both contributions are important for the ice core record at the NEEM site. The simulated Eemian precipitation-weighted warming of 2.4 K at the NEEM site is low compared to the ice core reconstruction, partially due to missing feedbacks related to ice sheet changes. Surface mass balance calculations with an energy balance model indicate potential mass loss in the north and southwestern parts of the ice sheet. The oceanic conditions favor increased accumulation in the southeast, while the insolation appears to be the dominant cause of the expected ice sheet reduction.
Effect of various climate databases on the results of dendroclimatic analysis
Authors: Sitko Roman , Vido Jaroslav , Škvarenina Jaroslav , Pichler Viliam , Scheer Ĺubomír , Škvareninová Jana , Nalevanková Paulína
Published: April 2016

Abstract. The paper deals with the comparison of the time series drawn from different climate databases. We compared the observed data with the modeled data of monthly and seasonal temperature means and precipitation totals. Reliable and longest available time series of such data represent the basic starting point of dendroclimatic analyses. We evaluated the differences in the growth response of spruce derived using different databases of the considered climatic variables. The stem cores used to derive the cross-correlation function were taken from Hårås locality situated in the boreal zone of the Swedish part of Lapland. We compared the observed records from the nearest weather stations situated 18, 40, 70 and 110 km away from the locality with the interpolated data from four modeled temperature databases and four modeled precipitation databases generated by KNMI Climate Explorer. The spatial resolution of the modeled databases was 0.5°  ×  0.5° of latitude and longitude or 1°  ×  1° respectively. The evaluation revealed that in all modeled databases systematic errors of different magnitudes occurred. We also found that the radial increments of spruce correlated more tightly with the temperature than with the precipitation in the area of interest. Hence, in the conditions of the boreal zone, temperature could be a more important factor with regard to tree-ring formation. Because of higher spatial variability seen in precipitation data when compared to temperature data, we conclude that the nearest weather station is the most suitable for dendroclimatic analysis leaning on precipitation. Drawing on these results we recommend that the modeled precipitation and temperature databases examined in our study are used for dendroclimatic analyses within areas featuring a sparse network of weather stations.
An ice sheet model of reduced complexity for paleoclimate studies
Authors: Neff Basil , Born Andreas , Stocker Thomas F.
Published: April 2016

Abstract. IceBern2D is a vertically integrated ice sheet model to investigate the ice distribution on long timescales under different climatic conditions. It is forced by simulated fields of surface temperature and precipitation of the Last Glacial Maximum and present-day climate from a comprehensive climate model. This constant forcing is adjusted to changes in ice elevation. Due to its reduced complexity and computational efficiency, the model is well suited for extensive sensitivity studies and ensemble simulations on extensive temporal and spatial scales. It shows good quantitative agreement with standardized benchmarks on an artificial domain (EISMINT). Present-day and Last Glacial Maximum ice distributions in the Northern Hemisphere are also simulated with good agreement. Glacial ice volume in Eurasia is underestimated due to the lack of ice shelves in our model. The efficiency of the model is utilized by running an ensemble of 400 simulations with perturbed model parameters and two different estimates of the climate at the Last Glacial Maximum. The sensitivity to the imposed climate boundary conditions and the positive degree-day factor β, i.e., the surface mass balance, outweighs the influence of parameters that disturb the flow of ice. This justifies the use of simplified dynamics as a means to achieve computational efficiency for simulations that cover several glacial cycles. Hysteresis simulations over 5 million years illustrate the stability of the simulated ice sheets to variations in surface air temperature.
Tropospheric water vapour isotopologue data (H216O, H218O and HD16O) as obtained from NDACC/FTIR solar absorption spectra
Authors: Barthlott Sabine , Schneider Matthias , Hase Frank , Blumenstock Thomas , Kiel Matthäus , Dubravica Darko , García Omaira E. , Sepúlveda Eliezer , Mengistu Tsidu Gizaw , Takele Kenea Samuel , Grutter Michel , Plaza Eddy F. , Stremme Wolfgang , Strong Kim , Weaver Dan , Palm Mathias , Warneke Thorsten , Notholt Justus , Mahieu Emmanuel , Servais Christian , Jones Nicholas , Griffith David W. T. , Smale Dan , Robinson John
Published: April 2016

Abstract. We report on the ground-based FTIR (Fourier Transform InfraRed) tropospheric water vapour isotopologue remote sensing data that have been recently made available via the database of NDACC (Network for the Detection of Atmospheric Composition Change; ftp://ftp.cpc.ncep.noaa.gov/ndacc/MUSICA/) and via doi:10.5281/zenodo.48902. Currently, data are available for 12 globally distributed stations. They have been centrally retrieved and quality filtered in the framework of the MUSICA project (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water). We explain particularities of retrieving the water vapour isotopologue state (vertical distribution of H216O, H218O and HD16O) and reveal the need for a new meta-data template for archiving such FTIR isotopologue data. We describe the format of different data components and give recommendations for correct data usage. Data are provided as two data types. The first type is best-suited for tropospheric water vapour distribution studies disregarding different isotopologues (comparison with radiosonde data, analyses of water vapour variability and trends, etc.). The second type is needed for analysing moisture pathways by means of {H2O,δD}-pair distributions.