bluuebunny/crossref_metadata_2025 huggingface dataset:
La conservation conventionnelle des ressources naturelles en Amérique centrale
Authors: Amilien Caroline , Mack Stephen , Chacón Carlos M. , Castro Rolando , Meza Andrea
Published: December 2015

Malgré les efforts déployés par les pays d'Amérique centrale pour

lutter contre la dégradation de l'environnement et fortifier leur réseau d'aires protégées, le rôle direct des gouvernements demeure limité du fait que de nombreux terrains importants du point de vue de la conservation sont des terrains privés. Il est donc extrêmement important de mettre à la disposition des propriétaires des mécanismes flexibles et attrayants qui les incitent à gérer leur terrain tout en conservant les ressources naturelles. Grâce à leur flexibilité, les servitudes de conservation peuvent être adaptées aux caractéristiques d'un pays, d'une région ainsi qu'aux besoins spécifiques de chaque propriétaire. Les objectifs de conservation peuvent également être réalisés par le recours à d'autres instruments conventionnels, tels que l'usufruit, le covenant ou l'accord de conservation. Cet article fait le point sur ces divers mécanismes et les problèmes liés à leur mise en œuvre.
La commission départementale de la liste d'aptitude aux fonctions de commissaire enquêteur
Authors: Tabarnoust Driss
Published: December 2015

La loi Barnier du 2 février 1995, relative au renforcement de la protection de l'environnement, ne semble pas encore avoir épuisé toutes ses ressources. Après la création et la mise en place effective de la Commission nationale du débat public prévue à l'article 2, voici venu le tour de la seconde commission, départementale celle-ci, prévue à l'article 3 de la loi procédant à un ajustement du droit des enquêtes publiques, mais dont l'importance n'est pas à négliger, en raison des attributions qui lui sont conférées.
Le droit européen de l'environnement à la lecture du traité d'Amsterdam : modifications et perspectives
Authors: Bär Stefani , Mazurek Anne-Gabrielle
Published: December 2015

Les changements apportés par le Traité d'Amsterdam (entré en vigueur le 1er mai 1999) expriment la volonté des parties contractantes de préparer l'Union européenne aux élargissements, de renforcer les aspects démocratiques de l'Union par la simplification et le développement de la procédure de codécision, et de rapprocher le Traité des citoyens de l'Union européenne. Ces modifications, qui devraient permettre une approche politique plus intégrée, marquent une avancée certaine quant à la place qu'occupera dorénavant la politique environnementale dans les actions et l'élaboration de la politique de la Communauté. L'introduction du principe de développement durable, l'intégration des questions environnementales, l'accroissement du pouvoir du Parlement européen dans l'élaboration de la législation environnementale et les précisions apportées à l'article 100 A (nouvel art. 95) peuvent en dépit de certaines ambiguïtés, être interprétées comme l'expression d'une réelle volonté politique de réserver une place majeure aux considérations environnementales.
Recherches archéologiques à Famars.(1986-1988)
Authors: Vanbruggbe Nathalie
Published: December 2015

Un projet de déviation routière sur la commune de Famars a donné lieu à des fouilles de sauvetage qui ont permis de compléter nos connaissances sur la partie occidentale du site gallo-romain.

- Au sud-ouest, la découverte de structures liées à une activité de production de céramique commune confirme l'existence d'un quartier artisanal de potiers dans ce secteur.

- L'extension du site vers l'ouest et le nord-ouest a pu être précisée par la mise au jour de plusieurs bâtiments arasés et de caves.

- L'existence d'une voie en direction du gué de Trith-Saint-Léger a pu être mise en évidence.
Les enduits peints d'époque sévérienne d'une caserne de la Classis Britannica à Boulogne-sur-Mer.
Authors: Belot Eric
Published: December 2015

Les enduits peints découverts sur le site de l'Enclos de l'Evéché à Boulogne-sur-Mer dans la chambre I de la caserne B du Camp de la Classis Britanica permettent d'appréhender deux décors, dont l'un, effondré d'un seul tenant face contre terre, donne lieu à une reconstitution d'environ 2x2,1 m de superficie. Celle-ci a été dans les premières analyses interprétée comme un plafond en considération de son schéma d'effondrement. L'examen de la composition ne permet cependant pas de trancher de manière définitive et nous préférons garder en l'état actuel des travaux un caractère d'hypothèse à cette identification. Ces décors sont datés par le contexte archéologique du début du 3e s. Ils s'intègrent à une série stylistique dont les principaux exemples sont situés en Gaule septentrionale et qui est habituellement placée dans la 2e moitié du 2e s. Les découvertes de Boulogne-sur-Mer permettent notamment de la «recentrer» vers l'époque sévérienne. Ce groupe stylistique comprend des décors linéaires offrant des compositions rythmiquement simples, où l'on retrouve des poncifs au traitement stylisé (guirlandes, boucliers), qui peuvent paraître emblématiques de la civilisation romaine dans ses données les plus essentielles. Ces décors linéaires peuvent être mis en parallèle avec le développement sous les derniers Antonins et les Sévères d'une vogue «archaïsante» qui, elle aussi, dans une perspective plus ostentatoire (architectures fictives, mégalographies), affirme la pérennité des valeurs décoratives les plus fondamentales du décor pictural romain.
Nouvelle lecture d'une plaque d'insculpation lilloise (1758-1793) conservée au musée de l'Hospice Comtesse à Lille
Authors: Montupet Béatrice
Published: December 2015

Aan de hand van een nieuw onderzoek van de in het Rijselse Hospice Comtessemuseum bewaarde merkenplaten en de studie van een aantal dokumenten in het stadsarchief kan men aan een plaat een nieuwe betekenis geven. De letters die gegraveerd werden in de plaat met het inventarisnummer 1912 M.L. 2269 worden nu gezien als controlemerken van de administratie van maten en gewichten tijdens de période 1758 tot 1793. Men kan zo vaststellen dat men moet wachten tot 1793 op een hervoming, niet van het systeem van maten en gewichten, maar van de toepassing van dit systeem. Nu men de tweehonderste verjaardag van de Revolutie viert komt deze vaststelling in een nieuw licht te staan.
Evidence for non-conservative current-induced forces in the breaking of Au and Pt atomic chains
Authors: Sabater Carlos , Untiedt Carlos , van Ruitenbeek Jan M
Published: December 2015

This experimental work aims at probing current-induced forces at the atomic scale. Specifically it addresses predictions in recent work regarding the appearance of run-away modes as a result of a combined effect of the non-conservative wind force and a ‘Berry force’. The systems we consider here are atomic chains of Au and Pt atoms, for which we investigate the distribution of break down voltage values. We observe two distinct modes of breaking for Au atomic chains. The breaking at high voltage appears to behave as expected for regular break down by thermal excitation due to Joule heating. However, there is a low-voltage breaking mode that has characteristics expected for the mechanism of current-induced forces. Although a full comparison would require more detailed information on the individual atomic configurations, the systems we consider are very similar to those considered in recent model calculations and the comparison between experiment and theory is very encouraging for the interpretation we propose.
Diversity-oriented synthesis of analogues of the novel macrocyclic peptide FR-225497 through late stage functionalization
Authors: Mukherjee Jyotiprasad , Sil Suman , Chattopadhyay Shital Kumar
Published: December 2015

A concise synthetic approach to a class of biologically interesting cyclic tetrapeptides is reported which involves a late-stage functionalization of a macrocyclic scaffold through cross metathesis in an attempt to create diversity. The utility of this protocol is demonstrated through the preparation of three structural analogues of the important naturally occurring histone deacetylase inhibitor FR-225497.
Lactobacillus rhamnosus GG supplementation during critical windows of gestation influences immune phenotype in Swiss albino mice offspring
Authors: Himaja N. , Hemalatha R. , Narendra Babu K. , Shujauddin M.
Published: December 2015

Probiotic supplementation during critical windows of gestation might have a significant influence on the infant’s immune phenotype. Swiss albino mice (F0 generation) aged 31 days were supplemented orally with probiotic Lactobacillus rhamnosus GG (LGG); and the supplementation was continued throughout mating, gestation and lactation. The pups (F1 generation) born to them were separated post weaning and received either the same probiotic supplementation as their mothers or were denied supplementation postnatally. Neutrophil phagocytic ability, splenocyte proliferation, immunoglobulins and cytokines were determined in both F0 and F1 pups. In addition, antibody response against hepatitis-B surface antigen (HBsAg) was determined in F1 pups. Probiotic supplementation had no effect on the neutrophil phagocytic ability and splenocyte proliferation index. The serum immunoglobulin G (IgG) and secretory IgA (s-IgA) among the probiotic supplemented group of F0 generation were significantly (P<0.05) higher compared to the controls. Similarly, the mean concentration of interleukin (IL)-10, IL-17 and interferon gamma (IFN-γ) among F0 probiotic group were significantly higher (P<0.05) compared to the control. Prenatal and postnatal probiotic supplementation in F1 pups led to similar results as F0 dams. Prenatal probiotic supplementation in F1 pups led to significantly (P<0.05) higher serum IgG (55.15±1.35 ng/ml) and intestinal s-IgA (77.9 ± 2.86 ng/mg protein) concentration when compared to the control. Similarly, IFN-γ concentration increased (P<0.05) with prenatal probiotic supplementation compared to the control. However, IL-10 and IL-17 concentrations of prenatal probiotic supplemented F1 pups were comparable to the control. As for the antibody response to HBsAg, prenatal probiotic supplementation led to enhanced HBsAg antibody response (471.4±3.97 U/ml) compared to the control. LGG affected the immune regulation and immune responses favourably in mothers and offspring. In addition, some of the beneficial effects of prenatal LGG supplementation extended into postnatal life of the offspring, thus suggesting possible immunoprogramming effect of LGG.
Effect of pre-exercise massage on exercise-induced muscle injury in sled dogs
Authors: Huneycutt H.W. , Davis M.S.
Published: December 2015

Previous necropsy studies have shown that up to 60% of sled dogs competing in endurance sled dog races have areas of muscle damage. Human athletes and trainers have maintained a strong belief, based mostly on personal experiences, that massage can be effective for pre-race preparation and expedited recovery between consecutive events. We proposed that massage could lessen the degree of creatine phosphokinase (CPK) release when utilised prior to endurance activities. A randomised crossover study was performed using minimally conditioned sled dogs from a sled dog racing kennel. Each dog in the treatment group received a 14 min massage immediately prior to controlled endurance exercise. The pre-exercise CPK activity was 64±11 IU/l (mean ± standard deviation). The difference between pre-exercise CPK and post-exercise CPK for both groups was expressed as delta CPK. The delta CPK for the massage group was 62±22 IU/l and 74±55 IU/l for the control group. There was no significant change in concentration of CPK between pre- and post-exercise in the treatment and control group (P=0.2282). The lack of a significant difference between the control and massage group suggests that pre-exercise massage may not reduce the severity of exercise-induced muscle damage.
‘Entomophagy’: an evolving terminology in need of review
Authors: Evans J. , Alemu M.H. , Flore R. , Frøst M.B. , Halloran A. , Jensen A.B. , Maciel-Vergara G. , Meyer-Rochow V.B. , Münke-Svendsen C. , Olsen S.B. , Payne C. , Roos N. , Rozin P. , Tan H.S.G. , van Huis A. , Vantomme P. , Eilenberg J.
Published: December 2015

There is growing interest in insects as human food in academia, food and agricultural industries, public institutions and the public at large. Yet many of the words and concepts used to describe these organisms and the human practices surrounding them are still rudimentary, compared to the diversity of the organisms themselves and the existing complexity and rapid evolution of the practices they aim to describe. The goals of this paper are to: (1) show how the roots of the term ‘entomophagy’ and its uses have evolved over time; (2) illustrate some of the term’s problems that necessitate its review; and (3) offer recommendations for use of the term in future research and other practice. Our paper offers a brief historical review of insect eating as described by certain Western cultural sources, explores some of the taxonomic ambiguities and challenges surrounding the category ‘insects’, and ultimately argues for more precise and contextual terminology in this both richly traditional and rapidly developing field.
Representaciones fotográficas en torno a la dictadura en la historiografía argentina reciente
Authors: Del Castillo Troncoso Alberto
Published: December 2015

El uso político y cultural de las fotografías desempeña un papel muy relevante en la construcción de la memoria en la historia reciente de Argentina y en particular en lo que se refiere a la última dictadura militar (1976-1983). En este ensayo se revisan algunas de las lecturas más significativas sobre este tema, llevadas a cabo por distintos investigadores argentinos en los últimos años, en las que se documenta la existencia de algunas imágenes que hacen visible la política de terrorismo de Estado instrumentada por los militares y llevada a cabo en distintos centros de cautiverio y exterminio.
A fotografia numa era de política de massas latinoamericana: as revistas S.Paulo (Brasil, 1936) e Rotofoto (México, 1938)
Authors: Sampaio Barbosa Carlos Alberto
Published: December 2015

O objetivo deste artigo é realizar uma comparação entre duas revistas ilustradas que tiveram vida efêmera na década de 1930 em seus respectivos países: a revista S.Paulo, (Brasil 1935/1936), em contraponto com revista a Rotofoto (México 1938). Busca-se examinar em especial como, entre os dois países, se constituíram temas comuns, que contribuíram para a construção do imaginário político latino-americano. Parte-se da hipótese de que apesar das as dificuldades de contatos mexicanos e brasileiros devido à diferença lingüística, distância e falta de um contato maior entre seus intelectuais, ocorreram intercâmbios de propostas políticas e culturais principalmente entre redes de sociabilidade de artistas e intelectuais. A comparação entre as duas revistas se insere dentro dessa problemática mais ampla. Ambas as revistas se apresentam como plataformas privilegiadas para o estudo comparado das sociedas mexicanas e brasileiras e de suas respectivas culturas visuais. Desse modo, o objetivo é flagrar como duas revistas culturais, que utilizaram amplamente a fotografia como elementos centrais de seu projeto gráfico, veicularam em suas páginas o momento político dos dois países.
Escuchar la escritura: la voz y la letra en João Cabral de Melo Neto
Authors: Pérez Villalón Fernando
Published: December 2015

El siguiente ensayo examina la relación de la obra del brasileño João Cabral de Melo Neto (1920-1999), lo musical y el ámbito de lo sonoro, como temas y como componentes de su propia poética. Para ello, se revisan en primer lugar algunas de sus declaraciones al respecto, y se propone una lectura a partir de ellas del poema “Fábula de Anfion”. En segundo lugar, se propone un examen de la grabación hecha por el autor de sus propios poemas como sintomática de las contradicciones que produce su resistencia a lo sonoro y lo vocal como dimensiones de la poesía, pero también como un esfuerzo por producir una performance consecuente con su estética de lo prosaico, lo antilírico y la precisión que el poeta asocia primordialmente al ámbito de lo visual y lo pictórico pero que permean necesariamente su contacto inevitable con el ámbito de lo sonoro.
Ropajes de la pasión. En torno al cine de Valeria Sarmiento
Authors: García Moggia Macarena
Published: December 2015

In this paper I carry out a comparative analysis of three movies directed by Chilean filmmaker Valeria Sarmiento: Notre mariage (1984), Amelia Lopes O’Neill (1991) and Rosa la china (2003). All of them can be considered as melodramas, because they place passional love, confronted with one or several obstacles, at the core of the plot. I examine the way in which Valeria Sarmiento stretches in different directions the threads of this plot, trying to identify the narratives and formal operations through which the filmmaker interrupts the audience’s emotional identification, and at the same time undermines the moral values of a culture that often writes passional love, especially feminine, in a melodramatic key.
Palabra, imagen y silencio: representación de la violencia política en La inquietante extrañez de Cecilia Echeverría y de Armando Uribe Arce
Authors: Cordero Cortés Rodrigo
Published: December 2015

El artículo propone una aproximación al libro La inquietante extrañez de Cecilia Echeverría y Armando Uribe desde la perspectiva de las relaciones entre texto e imagen. La noción de lo siniestro y la imagen del imbunche se postulan como dos claves para la comprensión de la representación de la violencia política en el contexto del periodo de la dictadura y de la post-dictadura chilena.
Nurse educators’ experiences of case-based education in a South African nursing programme
Authors: Daniels Felicity M. , Fakude Lorraine P. , Linda Ntombizodwa S. , Marie Modeste Rugira R.
Published: December 2015

Background: A school of nursing at a university in the Western Cape experienced an increase in student enrolments from an intake of 150 students to 300 students in the space of one year. This required a review of the teaching and learning approach to ensure that it was appropriate for effective facilitation of large classes. The case-based education (CBE) approach was adopted for the delivery of the Bachelor of Nursing programme in 2005.Aim: The aim of the study was to explore nurse educators’ experiences, current practices and possible improvements to inform best practice of CBE at the nursing school in the Western Cape.Methods: A participatory action research method was applied in a two day workshop conducted with nurse educators in the undergraduate nursing programme. The nominal group technique was used to collect the data.Results: Three themes emerged from the final synthesis of the findings, namely: teaching and learning related issues, student issues and teacher issues. Amongst other aspects, theory and practice integration, as well as the need for peer support in facilitation of CBE, were identified as requiring strengthening.Conclusion: It was concluded that case-based education should continue to be used in the school, however, more workshops should be arranged to keep educators updated and new staff orientated in respect of this teaching and learning approach.
Gastrojejunostomy without partial gastrectomy to manage duodenal stenosis in a dog
Authors: Nel Johannes J. , Du Plessis Cornelius J. , Coetzee Gert L.
Published: December 2015

A nine-year-old female Rottweiler with a history of repeated gastrointestinal ulcerations and three previous surgical interventions related to gastrointestinal ulceration presented with symptoms of anorexia and intermittent vomiting. Benign gastric outflow obstruction was diagnosed in the proximal duodenal area. The initial surgical plan was to perform a pylorectomy with gastroduodenostomy (Billroth I procedure), but owing to substantial scar tissue and adhesions in the area a palliative gastrojejunostomy was performed. This procedure provided a bypass for the gastric contents into the proximal jejunum via the new stoma, yet still allowed bile and pancreatic secretions to flow normally via the patent duodenum. The gastrojejunostomy technique was successful in the surgical management of this case, which involved proximal duodenal stricture in the absence of neoplasia. Regular telephonic followup over the next 12 months confirmed that the patient was doing well.
Experiences of general practitioners in the Ga-Rankuwa and Mabopane areas in dealing with patients who have sexual problems
Authors: Mills Benjamin , Govender Indiran , Hugo Jannie
Published: December 2015

Background: Sexual problems are common. Many patients with sexual health dysfunction use self-help literature or are often managed in general practice. However, many general practitioners (GPs) find it difficult to discuss sexual health issues because they feel uncomfortable with this and lack training in these matters. These GPs are now referring patients with sexual dysfunction to specialists.Aim: We sought to explore how GPs working in the Mabopane and Ga-Rankuwa areas of handle sexual problems of their patients.Setting: The setting was the Mabopane and Ga-Rankuwa areas of North-West Tshwane, in Gauteng Province.Methods: A qualitative study comprising eight free attitude interviews with purposefully selected four male and four female GPs. All interviews were conducted in English and tape-recorded. Field notes in the form of a detailed diary was kept. The tapes were transcribed verbatim, and the transcriptions were checked against the tapes for omissions and inaccuracies.Results: Six themes emerged from the interviews: causes of sexual problems; presentation of sexual problems to the doctor; management of sexual health problems; sex is a taboo topic; society’s need for sexual health discussions, and these discussions have already begun; previous limited exposure and training, and a need for more sexual health training.Conclusion: This study confirms earlier findings that patients could be either reluctant to discuss their problems or are open about them when presenting to doctors with sexual dysfunction. GPs were not exposed to sexual health training at medical school and, because of this shortcoming, felt that training in sexual medicine should be part of the curriculum.
Reading Psalms, and other urban poems, in a fractured city
Authors: De Beer Stephanus
Published: December 2015

This article was an attempt to (re-)read Psalms in the context of fractured cities, marked by socio-economic inequalities, woundedness, migration and exclusion. It explored urban motifs in selected psalms and considered their possible meanings in relation to both the socio-cultural contexts in which they were written but also how they could be read and understood today. It proposed the Psalms as urban poetry, and considered poems of praise, lament and resistance. It brought the Psalms into conversation both with �remixed� psalms and also with other urban poems. A �remix� is a technical term usually associated with altering, adding or changing songs or music into a new version more appropriate or suitable for a new context. It is essentially a genre that emerged from within urban popular culture. Finally, I suggested that an understanding of the Psalms as urban poetry of praise, lament and resistance, in conversation with other urban poems, can serve as a resource to unshackle our faith from the temple, from one city, or from human institutions, evoking a daring new imagination for a new people, new city and new creation.Intradisciplinary and/or interdisciplinary implications: The article explores contextual readings of the Psalms as urban poetry, and retrieves other urban poems from different genres, both in order to inform urban theological discourse and contextual theological reflections on the fractured city.
Efficacy of Dasatinib in a CML Patient in Blast Crisis with F317L Mutation: A Case Report and Literature Review
Authors: Morozova E.V. , Vlasova Y.Y. , Pryanishnikova M.V. , Lepik K.V. , Afanasyev B.V.
Published: December 2015

The introduction of tyrosine kinase inhibitors (TKIs) in the treatment of chronic myeloid leukemia (CML) has significantly increased survival rate and quality of life for patients with CML. Despite the high efficacy of imatinib, not all patients benefit from this treatment. Resistance to imatinib can develop from a number of mechanisms. One of the main reasons for treatment failure is a mutation in the BCR-ABL gene, which leads to therapy resistance and clonal evolution. Clearly, new treatment approaches are required for patients who are resistant to imatinib. However, mutated clones are usually susceptible to second-generation TKIs, such as nilotinib and dasatinib. The choice of the therapy depends on the type of mutation. A large trial program showed that dasatinib is effective in patients previously exposed to imatinib. However, for a minority of patients who experience treatment failure with TKI or progress to advanced-phase disease, allogeneic stem cell transplantation (allo-SCT) remains the therapeutic option. In spite of the high curative potential of allo-SCT, its high relapse rate still requires a feasible strategy of posttransplant treatment and prophylaxis. We report a case of a CML patient with primary resistance to first-line TKI therapy. The patient developed an undifferentiated blast crisis. Before dasatinib therapy, the patient was found to have an F317L mutation. He was successfully treated with dasatinib followed by allo-SCT. In the posttransplant period, preemptive dasatinib treatment was used to prevent disease relapse.
Interpreting Clinical Trial Outcomes for Optimal Patient Care: A Survey of Clinicians and Trainees
Authors: Caverly Tanner J. , Matlock Daniel D. , Prochazka Allan V. , Lucas Brian P. , Hayward Rodney A.
Published: December 2015

Background

Evaluation of the clinical importance of outcomes in research studies is an essential element of clinical decision making.

Objective

To understand how clinicians and trainees weigh the importance of different types of clinical outcomes in drug trials.

Methods

A self-administered paper survey contained 4 scenarios asking participants to rate (1, “no proof” to 10, “good proof”) the extent to which 4 study outcomes provided “proof that the new drug might help people.” Outcomes included (1) a surrogate outcome; (2) a surrogate-enriched composite outcome; (3) stroke mortality; and (4) all-cause mortality. The primary study metrics were mean ratings for each of the 4 outcome types, and the proportion ranking outcome importance of all-cause mortality > stroke mortality > surrogate-enriched composite or surrogate alone.

Results

A convenience sample of 549 clinicians and trainees at 2 medical centers completed the survey (response rate: 87% medical students, 80% internal medicine residents, 69% general medicine faculty, and 41% physician experts). The surrogate-enriched composite outcome and stroke mortality were rated the most important evidence for benefit (6.6 and 6.4, respectively), with all-cause mortality and a surrogate outcome being rated significantly lower (5.2 and 4.6, respectively). In addition, 48% of clinicians rated improvement in all-cause mortality as more valuable than an improvement in a surrogate marker. Only 21% rated all-cause mortality as more valuable than a surrogate-enriched composite outcome.

Conclusions

These findings raise concerns that clinicians and trainees may not interpret trial evidence in a way that promotes the best care for patients.
OMI tropospheric NO2 profiles from cloud slicing: constraints on surface emissions, convective transport and lightning NOx
Authors: Belmonte Rivas M. , Veefkind P. , Eskes H. , Levelt P.
Published: December 2015

Abstract. We derive annual and seasonal global climatologies of tropospheric NO2 profiles from OMI cloudy observations for the year 2006 using the cloud-slicing method on six pressure levels centered at about 280, 380, 500, 620, 720 and 820 hPa. A comparison between OMI and the TM4 model tropospheric NO2 profiles reveals striking overall similarities, which confer great confidence to the cloud-slicing approach to provide details that pertain to annual as well as seasonal means, along with localized discrepancies that seem to probe into particular model processes. Anomalies detected at the lowest levels can be traced to deficiencies in the model surface emission inventory, at mid-tropospheric levels to convective transport and horizontal advective diffusion, and at the upper tropospheric levels to model lightning NOx production and the placement of deeply transported NO2 plumes such as from the Asian summer monsoon. The vertical information contained in the OMI cloud-sliced NO2 profiles provides a global observational constraint that can be used to evaluate chemistry transport models (CTMs) and guide the development of key parameterization schemes.
Tuning of a convective gravity wave source scheme based on HIRDLS observations
Authors: Trinh Q. T. , Kalisch S. , Preusse P. , Ern M. , Chun H.-Y. , Eckermann S. D. , Kang M.-J. , Riese M.
Published: December 2015

Abstract. Convection as one dominant source of atmospheric gravity waves (GWs) has been in focus of investigation over recent years. However, its spatial and temporal forcing scales are not well known. In this work we address this open issue by a systematic verification of free parameters of the Yonsei convective GW source scheme based on observations from the High Resolution Dynamics Limb Sounder (HIRDLS). Observational constraints are taken into account by applying a comprehensive observational filter on the simulated GWs. By this approach, only long horizontal scale convective GWs are addressed. Results show that effects of long horizontal scale convective GWs can be successfully simulated by the superposition of three or four combinations of parameter sets reproducing the observed GW spectrum. These selected parameter sets are different for northern and southern summer. Although long horizontal scale waves are only part of the full spectrum of convective GWs, the momentum flux of these waves are found to be significant and relevant for the driving of the QBO. The zonal momentum balance is considered in vertical cross sections of GW momentum flux (GWMF) and GW drag (GWD). Global maps of the horizontal distribution of GWMF are considered and consistency between simulated results and HIRDLS observations is found. The latitude dependence of the zonal phase speed spectrum of GWMF and its change with altitude is discussed.
Satellite observations of stratospheric hydrogen fluoride and comparisons with SLIMCAT calculations
Authors: Harrison J. J. , Chipperfield M. P. , Boone C. D. , Dhomse S. S. , Bernath P. F. , Froidevaux L. , Anderson J. , Russell J.
Published: December 2015

Abstract. The vast majority of emissions of fluorine-containing molecules are anthropogenic in nature, e.g. chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and hydrofluorocarbons (HFCs). Many of these fluorine-containing species deplete stratospheric ozone, and are regulated by the Montreal Protocol. Once in the atmosphere they slowly degrade, ultimately leading to the formation of HF, the dominant reservoir of stratospheric fluorine due to its extreme stability. Monitoring the growth of stratospheric HF is therefore an important marker for the success of the Montreal Protocol. We report the comparison of global distributions and trends of HF measured in the Earth's atmosphere by the satellite remote-sensing instruments ACE-FTS (Atmospheric Chemistry Experiment Fourier Transform Spectrometer), which has been recording atmospheric spectra since 2004, and HALOE (HALogen Occultation Experiment), which recorded atmospheric spectra between 1991 and 2005, with the output of SLIMCAT, a state-of-the-art three-dimensional chemical transport model. In general the agreement between observation and model is good, although the ACE-FTS measurements are biased high by ∼ 10 % relative to HALOE. The observed global HF trends reveal a substantial slowing down in the rate of increase of HF since the 1990s: 4.97 ± 0.12 % year-1 (1991–1997; HALOE), 1.12 ± 0.08 % year-1 (1998–2005; HALOE), and 0.52 ± 0.03 % year-1 (2004–2012; ACE-FTS). In comparison, SLIMCAT calculates trends of 4.01, 1.10, and 0.48 % year-1, respectively, for the same periods; the agreement is very good for all but the earlier of the two HALOE periods. Furthermore, the observations reveal variations in the HF trends with latitude and altitude, for example between 2004 and 2012 HF actually decreased in the Southern Hemisphere below ∼ 35 km. SLIMCAT calculations broadly agree with these observations, most notably between 2004 and 2012. Such variations are attributed to variability in stratospheric dynamics over the observation period.
Automatic volcanic ash detection from MODIS observations using a back-propagation neural network
Authors: Gray T. M. , Bennartz R.
Published: December 2015

Abstract. Due to the climate effects and aviation threats of volcanic eruptions, it is important to accurately locate ash in the atmosphere. This study aims to explore the accuracy and reliability of training a neural network to identify cases of ash using observations from the Moderate Resolution Imaging Spectroradiometer (MODIS). Satellite images were obtained for the following eruptions: Kasatochi, Aleutian Islands, 2008; Okmok, Aleutian Islands, 2008; Grímsvötn, northeastern Iceland, 2011; Chaitén, southern Chile, 2008; Puyehue-Cordón Caulle, central Chile, 2011; Sangeang Api, Indonesia, 2014; and Kelut, Indonesia, 2014. The Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to obtain ash concentrations for the same archived eruptions. Two back-propagation neural networks were then trained using brightness temperature differences as inputs obtained via the following band combinations: 12–11, 11–8.6, 11–7.3, and 11 μm. Using the ash concentrations determined via HYSPLIT, flags were created to differentiate between ash (1) and no ash (0) and SO2-rich ash (1) and no SO2-rich ash (0) and used as output. When neural network output was compared to the test data set, 93 % of pixels containing ash were correctly identified and 7 % were missed. Nearly 100 % of pixels containing SO2-rich ash were correctly identified. The optimal thresholds, determined using Heidke skill scores, for ash retrieval and SO2-rich ash retrieval were 0.48 and 0.47, respectively. The networks show significantly less accuracy in the presence of high water vapor, liquid water, ice, or dust concentrations. Significant errors are also observed at the edge of the MODIS swath.
Can AERONET data be used to accurately model the monochromatic beam and circumsolar irradiances under cloud-free conditions in desert environment?
Authors: Eissa Y. , Blanc P. , Wald L. , Ghedira H.
Published: December 2015

Abstract. Routine measurements of the beam irradiance at normal incidence include the irradiance originating from within the extent of the solar disc only (DNIS), whose angular extent is 0.266° ± 1.7 %, and from a larger circumsolar region, called the circumsolar normal irradiance (CSNI). This study investigates whether the spectral aerosol optical properties of the AERONET stations are sufficient for an accurate modelling of the monochromatic DNIS and CSNI under cloud-free conditions in a desert environment. The data from an AERONET station in Abu Dhabi, United Arab Emirates, and the collocated Sun and Aureole Measurement instrument which offers reference measurements of the monochromatic profile of solar radiance were exploited. Using the AERONET data both the radiative transfer models libRadtran and SMARTS offer an accurate estimate of the monochromatic DNIS, with a relative root mean square error (RMSE) of 6 % and a coefficient of determination greater than 0.96. The observed relative bias obtained with libRadtran is +2 %, while that obtained with SMARTS is −1 %. After testing two configurations in SMARTS and three in libRadtran for modelling the monochromatic CSNI, libRadtran exhibits the most accurate results when the AERONET aerosol phase function is presented as a two-term Henyey–Greenstein phase function. In this case libRadtran exhibited a relative RMSE and a bias of respectively 27 and −24 % and a coefficient of determination of 0.882. Therefore, AERONET data may very well be used to model the monochromatic DNIS and the monochromatic CSNI. The results are promising and pave the way towards reporting the contribution of the broadband circumsolar irradiance to standard measurements of the beam irradiance.
Hydroxy fatty acids in fresh snow samples from northern Japan: long-range atmospheric transport of Gram-negative bacteria by Asian winter monsoon
Authors: Tyagi P. , Yamamoto S. , Kawamura K.
Published: December 2015

Abstract. Hydroxy fatty acids (FAs) in fresh snow from Sapporo, one of the heaviest snowfall regions in the world, have been studied to ascertain the airborne bacterial endotoxin concentrations and their biomass. The presence of β-hydroxy FAs (C9–C28), constituents of the Gram-negative bacterium (GNB), suggests long-range transport of soil microbes. Likewise, the occurrence of α- and ω-hydroxy FAs (C9–C30 and C9–C28, respectively) in snow reveals their contribution from epicuticular waxes and soil microorganisms. Estimated endotoxin and GNB mass can aid in assessing their possible impacts on the diversity and functioning of aquatic and terrestrial ecosystems, as well as lethal effects on pedestrians through dispersal of microbes. Air mass back trajectories together with hydroxy FAs reveal their sources from Siberia, the Russian Far East and northern China by the Asian monsoon. This study highlights the role of fresh snow that reduces the human health risk of GNB and endotoxin by the scavenging from air.
Stable isotopes in barnacles as a tool to understand green sea turtle (Chelonia mydas) regional movement patterns
Authors: Detjen M. , Sterling E. , Gómez A.
Published: December 2015

Abstract. Sea turtles are migratory animals that travel long distances between their feeding and breeding grounds. Traditional methods for researching sea turtle migratory behavior have important disadvantages, and the development of alternatives would enhance our ability to monitor and manage these globally endangered species. Here we report on the isotope signatures in green sea-turtle (Chelonia mydas) barnacles (Platylepas sp.) and discuss their potential relevance as tools with which to study green sea turtle migration and habitat use patterns. We analyzed oxygen (δ18O) and carbon (δ13C) isotope ratios in barnacle calcite layers from specimens collected from green turtles captured at the Palmyra Atoll National Wildlife Refuge (PANWR) in the central Pacific. Carbon isotopes were not informative in this study. However, the oxygen isotope results suggest likely regional movement patterns when mapped onto a predictive oxygen isotope map of the Pacific. Barnacle proxies could therefore complement other methods in understanding regional movement patterns, informing more effective conservation policy that takes into account connectivity between populations.
Ash leachates from some recent eruptions of Mount Etna (Italy) and Popocatépetl (Mexico) volcanoes and their impact on amphibian living freshwater organisms
Authors: D'Addabbo M. , Sulpizio R. , Guidi M. , Capitani G. , Mantecca P. , Zanchetta G.
Published: December 2015

Abstract. Leaching experiments were carried out on fresh ash samples from Popocatépetl 2012, Etna 2011, and Etna 2012 eruptions, in order to investigate the release of compounds in both double-deionized and lake (Lake Ohrid, FYR of Macedonia) waters. The experiments were carried out using different grain sizes and variable stirring times (from 30 min to 7 days). Results were discussed in the light of changing pH and release of compounds for the different leachates. In particular, Etna samples induced alkalinization, and Popocatépetl samples induced acidification of the corresponding leachates. The release of different elements does not show correlation with the stirring time, with the measured maximum concentrations reached in the first hours of washing. General inverse correlation with grain size was observed only for Na+, K+, Cl−, Ca2+, Mg2+, SO42−, and Mn2+, while the other analysed elements show a complex, scattering relationship with grain size. Geochemical modelling highlights leachates' saturation only for F and Si, with Popocatépetl samples sometimes showing saturation in Fe. The analysed leachates are classified as undrinkable for humans on the basis of European laws, due to excess in F−, Mn2+, Fe, and SO42− (the latter only for Popocatépetl samples). Finally, the Etna 2012 and Popocatépetl leachates were used for toxicity experiments on living biota (Xenopus laevis). They are mildly toxic, and no significant differences exist between the toxic profiles of the two leachates. In particular, no significant embryo mortality was observed; while even at high dilutions, the leachates produced more than 20 % of malformed larvae.
Autotrophic fixation of geogenic CO2 by microorganisms contributes to soil organic matter formation and alters isotope signatures in a wetland mofette
Authors: Nowak M. E. , Beulig F. , von Fischer J. , Muhr J. , Küsel K. , Trumbore S. E.
Published: December 2015

Abstract. To quantify the contribution of autotrophic microorganisms to organic matter (OM) formation in soils, we investigated natural CO2 vents (mofettes) situated in a wetland in northwest Bohemia (Czech Republic). Mofette soils had higher soil organic matter (SOM) concentrations than reference soils due to restricted decomposition under high CO2 levels. We used radiocarbon (Δ14C) and stable carbon (δ13C) isotope ratios to characterize SOM and its sources in two mofettes and compared it with respective reference soils, which were not influenced by geogenic CO2. The geogenic CO2 emitted at these sites is free of radiocarbon and enriched in 13C compared to atmospheric CO2. Together, these isotopic signals allow us to distinguish C fixed by plants from C fixed by autotrophic microorganisms using their differences in 13C discrimination. We can then estimate that up to 27 % of soil organic matter in the 0–10 cm layer of these soils was derived from microbially assimilated CO2. Isotope values of bulk SOM were shifted towards more positive δ13C and more negative Δ14C values in mofettes compared to reference soils, suggesting that geogenic CO2 emitted from the soil atmosphere is incorporated into SOM. To distinguish whether geogenic CO2 was fixed by plants or by CO2 assimilating microorganisms, we first used the proportional differences in radiocarbon and δ13C values to indicate the magnitude of discrimination of the stable isotopes in living plants. Deviation from this relationship was taken to indicate the presence of microbial CO2 fixation, as microbial discrimination should differ from that of plants. 13CO2-labelling experiments confirmed high activity of CO2 assimilating microbes in the top 10 cm, where δ13C values of SOM were shifted up to 2 ‰ towards more negative values. Uptake rates of microbial CO2 fixation ranged up to 1.59 ± 0.16 μg gdw−1 d−1. We inferred that the negative δ13C shift was caused by the activity of autotrophic microorganisms using the Calvin–Benson–Bassham (CBB) cycle, as indicated from quantification of cbbL/cbbM marker genes encoding for RubisCO by quantitative polymerase chain reaction (qPCR) and by acetogenic and methanogenic microorganisms, shown present in the mofettes by previous studies. Combined Δ14C and δ13C isotope mass balances indicated that microbially derived carbon accounted for 8–27 % of bulk SOM in this soil layer. The findings imply that autotrophic microorganisms can recycle significant amounts of carbon in wetland soils and might contribute to observed radiocarbon reservoir effects influencing Δ14C signatures in peat deposits.
Variability of projected terrestrial biosphere responses to elevated levels of atmospheric CO2 due to uncertainty in biological nitrogen fixation
Authors: Meyerholt J. , Zaehle S. , Smith M. J.
Published: December 2015

Abstract. Including a terrestrial nitrogen (N) cycle in Earth system models has led to substantial attenuation of predicted biosphere-climate feedbacks. However, the magnitude of this attenuation remains uncertain. A particularly important, but highly uncertain process is biological nitrogen fixation (BNF), which is the largest natural input of N to land ecosystems globally. In order to quantify this uncertainty, and estimate likely effects on terrestrial biosphere dynamics, we applied six alternative formulations of BNF spanning the range of process formulations in current state-of-the-art biosphere models within a common framework, the O-CN model: a global map of static BNF rates, two empirical relationships between BNF and other ecosystem variables (net primary productivity (NPP) and evapotranspiration), two process-oriented formulations based on plant N status, and an optimality-based approach. We examined the resulting differences in model predictions under ambient and elevated atmospheric [CO2] and found that the predicted global BNF rates and their spatial distribution for contemporary conditions were broadly comparable, ranging from 95 to 134 Tg N yr−1 (median 119 Tg N yr−1), despite distinct regional patterns associated with the assumptions of each approach. Notwithstanding, model responses in BNF rates to elevated levels of atmospheric [CO2] (+200 ppm) ranged between −4 Tg N yr−1 (−3 %) and 56 Tg N yr−1 (+42 %) (median 7 Tg N yr−1 (+8 %)). As a consequence, future projections of global ecosystem carbon storage (+281 to +353 Pg C, or +13 to +16 %), as well as N2O emission (−1.6 to +0.5 Tg N yr−1, or −19 to +7 %) differed significantly across the different model formulations. Our results emphasize the importance of better understanding the nature and magnitude of BNF responses to change-induced perturbations, particularly through new empirical perturbation experiments and improved model representation.