bluuebunny/crossref_metadata_2025 huggingface dataset:
Test biologique des mycotoxines aflatoxine B1 et patuline par utilisation de Bacillus thuringiensis
Authors: Boutibonnes Ph. , Jacquet Jean
Published: March 2018

L’aflatoxine B1 et la patuline, deux mycotoxines parmi les plus connues, possèdent des propriétés antibactériennes qui peuvent être révélées par Bacillus thuringiensis. La coumarine et le thioglycolate de sodium inhibent spécifiquement cette activité antimicrobienne. Il est possible de constituer un test biologique, soit de recherche directe, soit de confirmation de l'analyse biochimique des deux mycotoxines, notamment dans les aliments, selon le principe du double test : épreuve et contre-épreuve spécifique.
Récente contamination de la chaîne alimentaire due aux retombées radioactives en France
Authors: Moire J. , Nin F. , Gilles G. , Bernard F. , Stevenin G. , Ramon Gaston , Guillou J.-P.
Published: March 2018

A la suite d’une expérience nucléaire récente, les retombées ont à nouveau contaminé des produits alimentaires en France, alors que le niveau antérieur de radioactivité était voisin de zéro.

A partir de l’étude de l'activité des thyroïdes de bovins et des précipités oxalatiques du lait, les auteurs étudient au moyen de graphiques l'intensité de la contamination et les dangers encourus par l'homme et les animaux.

Ils concluent en montrant que le danger a été faible, mais que la vigilance est de rigueur.
Préparation de cultures cellulaires primaires de rein de levraut
Authors: Louzis Claude , Descarpentries R.
Published: March 2018

The authors describe a technique for preparing primary cellular cultures of leveret kidneys. The result obtained should facilitate the research «in vivo» of virus in the hare.
Effet nutritionnel de la perfusion intracæcale d’urée chez le lapin nourri avec un régime aprotéique
Authors: Salse A. , Raynaud Paul
Published: March 2018

L’effet de l’urée donnée par voie intracæcale à des lapins recevant une ration nitroprive est positif. En utilisant 0,5 g d’azote uréique par animal adulte et par jour, il est possible de maintenir leur poids corporel...
Comparaison de deux méthodes de chromatographie en couche mince sur gel de silice pour le dosage des aflatoxines B1 et G1 et de l’ochratoxine A
Authors: Faucon M. , Teherani A. , Tantaoui Elaraki Abdelrhani , Jacquet Jean
Published: March 2018

The authors have studied the factors which behave on visual method, using object-slides, for microscopic examinations, and on fluorodensitometry, employing TLD 100 Vitatron and 20 x 20 cm chromatography plates. They have compared the two technics and concluded that they are in good concordance.
Contamination des produits laitiers par les diphényles polychlorés
Authors: Richou-Bac  , Venant A.
Published: March 2018

Polychlorinated Biphenyl residues are detected for the first time in French dairy products in 1975.

In 1976, an investigation specially based on contaminated areas shows off a higher pollution (28 p. 100 of samples out of 1 012 in total).

4JD3 ppm (calculated on the fat) is the average residual amount in 1975 and 1,70 ppm in 1976.

Alt the long term toxicologic problems of PCB or their chlorinated impurities are not yet resolved. In France, safety measures were taken in 1975 (use only in closed circuit).
Recherches sur la thérapeutique et la prévention de la cysticercose bovine à Cysticercus bovis.
Authors: Wikerhauser Th.
Published: March 2018

D’après les recherches que nous avons entreprises sur la prévention et la thérapeutique de la cysticercose bovine à Cysticercus bovis, il semble qu’on puisse obtenir la désinfection des locaux par l’Halamid à 0,5 p. 100 ou celle de l’herbe des pâturages suspects par ensilage, alors que ni la vaccination, ni la chimiothérapie ne sont encore capables d’application pratique.
Virulence du lait et du sang au cours de l’évolution de la fièvre aphteuse expérimentale chez les vaches laitières
Authors: Dhennin Léone , Labié Jacques
Published: March 2018

Through out our various tests a virulent cow milk has been obtained either by the inoculation of the Foot-and-Mouth disease virus suspension to milk cows or by contamination. It has been observed as well that the titre of the milk produced by inoculated milk cows was superior to the one of contaminated milk cows. The milk appeared virulent before the rise in temperature and the appearance of clinical symptômes. The antibodies appeared early in the milk although some virus was still present in it.
Les parasitoses animales peuvent-elles régresser ? Aperçus de la situation actuelle et réflexions prospectives
Authors: Touratier L.
Published: March 2018

The present situation of animal parasitoses in the world having been briefly recalled, improvments in antiparasite control are being considered. Research should enable new chemical parasiticides or vaccines to be realised fairly soon. Biological control must also be studied.

To obtain a reduction in the incidence of animal parasitoses it will be necessary to establish a series of complex measures. In particular the applying of new means resulting from research work should be associated with modern methods of rearing taking into account the epizootiological features of these diseases.
Absorption des érythrocytes de cobaye sur différentes sous-populations leucocytaires du cheval.
Authors: Vautherot J. F. , Salmon Henri
Published: March 2018

A la suite de la mise en contact, par simple centrifugation d’érythrocytes de cobayes et de lymphocytes de chevaux sains ou atteints d'anémie infectieuse des équidés, on met en évidence leur hémadsorption élective sur une sous-population de lymphocytes sanguins. Cette sous-population recouvre 20,6 p. 100 des lymphocytes, pourcentage qui s’élève à 37,5 p. 100 en présence de dextran.

L’observation que les lymphocytes thymiques forment ces mêmes rosettes, dans une proportion allant de 51 p. 100 à 71 p. 100, en présence de dextran, suggère que cette interaction est spécifique des lymphocytes thymo-dépendants. Des expériences de déplétion sélective confirment cette hypothèse.

Ce phénomène, en outre, a pu être observé sur la quasi-totalité des monocytes et polynucléaires sanguins.
Importance de l’équilibre de la ration des animaux de laboratoire dans les études toxicologiques
Authors: Ferrando Raymond
Published: March 2018

Relationship between Toxicants and diet are an important aspect of Toxicological evaluation. Concerning this question the gross phenomenon is to be considered with accuracy and always detailed informations must be given on nutritional parameters. A such remark has a general value for the objectiveness of judgement in the field of biology.
Quelques observations et commentaires sur l’évolution de la lutte contre la fièvre aphteuse au Moyen-Orient, au cours des quinze dernières années (1962-1977)
Authors: Santucci J.
Published: March 2018

Analyse de l’évolution de la lutte anti-aphteuse dans la région du Moyen-Orient depuis l’apparition du virus africain SAT 1 en 1962. Résultats positifs des actions de coopération instituées à cette occasion sous les auspices des Organisations Internationales : protection du chepel européen contre trois épizooties -SAT 1 -A 22 -ASIA 1 ; institution progressive dans de nombreux pays du Moyen-Orient de programmes de vaccination anti-aphteuse pour répondre aux besoins créés par l’évolution économique récente en matière d'élevage et d’échanges internationaux des viandes.
Recherche et dosage par radioimmunologie d’estradiol 17β, d'estrone et de D.E.S. sur de jeunes bovins traités aux anabolisants. Aspects législatifs
Authors: Richou-Bac Lucien , Pochard Marie-France , Boursier Bernadette
Published: March 2018

L’analyse des teneurs en estradiol 17β, estrone et D.E.S. dans le plasma, le muscle, le foie a été réalisée par radioimmunologie pendant 2 mois sur des jeunes bovins traités à l’estradiol 17β (+ acétate de trenbolone) d’une part, au D.E.S. d’autre part. Une large répartition des teneurs en estradiol 17β, pouvant atteindre le double des valeurs endogènes enregistrées chez les témoins, a été observée. Les résidus de D.E.S., qui ont été retrouvés et quantifiés après 2 jours disparaissent rapidement.

L’application de la loi du 27 novembre 1976 présente certaines difficultés en ce qui concerne les œstrogènes naturels. Il n’en est pas de même pour le D.E.S. et ses dérivés dont la tolérance O peut et doit être appliquée avec rigueur.
Tuberculose bovine. Amélioration du dépistage des anergiques et douteux
Authors: Gayot Georges , Camy M. , Réveillon J. J. , Augier J. , Brétenet G. , Dufrêne Mireille
Published: March 2018

Quatre-cent-soixante-dix-neuf animaux appartenant à trente-deux troupeaux reconnus infectés ont été tuberculinés par voie intradermique avec des doses croissantes de tuberculine bovine (1600 -5400 et 12 000 unités). Cent-quarante-neuf animaux appartenant à cinq troupeaux reconnus sains ont servi de témoins négatifs. A partir des résultats d’abattoir observés sur cent-quatre-vingt-dix-sept animaux abattus dont cent-dix-huit présentaient des lésions, il est montré que la dose forte de tuberculine améliore le dépistage de 21 p. 100, ne laissant subsister que 9,6 p. 100 d’anergiques.
Influence du traumatisme chirurgical sur la vitamine A du foie et du plasma du rat
Authors: Ferrando Raymond
Published: March 2018

Le traumatisme chirurgical et les circonstances qui l'accompagnent déterminent, chez le rat, une usure de la réserve hépatique de vitamine A et l'abaissement de son taux plasmatique. Les conséquences pratiques de ce phénomène sont soulignées.
Etude de quatre peintures rupestres de l'Ennedi et du Tassili N'ajjer
Authors: Petit J.-P.
Published: March 2018

Dans le cadre des grandes interrogations sur la domestication des bovins et sur leurs migrations en Afrique, une analyse de quatre peintures rupestres du Tassili et de l'Ennedi est tentée.

Le but poursuivi est de parvenir à en tirer une signification accessible aux hommes d’aujourd’hui, malgré 5000 ans de distance avec ces civilisations de pasteurs.

L'étude confirme certaines hypothèses classiques de filiation et permet d’ébaucher l'hypothèse d'un rapprochement entre les bovins de ces fresques et les actuels Kouri, taurins du lac Tchad.
Réponse immunitaire humorale et cellulaire du porc à la suite de la vaccination ou de l'infection sub-clinique par le virus de la peste porcine classique
Authors: Corthier G. , Labadie J.-P. , Petit E.
Published: March 2018

Humoral immune response (séroneutralisation : S.N., passive hemagglutination : H.A.P.) and cellular immune response (lymphocyte transformation test L.T.T.) were analysed on vaccinated pigs and pigs infected with swine fever chronical strains (S.F.C. ). Vaccinated animals developp an intense S.N. antibody production but a transient H.A.P. antibody synthesis ; no cellular immune response can be detect. Not any S.N. antibody were detected in S.F.C. infected pigs but an H.A.P. antibody production and a brief T.T.L. response (20 days post infection) were observed.
Électrophorèse des protéines urinaires chez le chien
Authors: Groulade J. , Groulade Paul , Groslambert Paule
Published: March 2018

Electrophoresis of proteins urinary is studied in the dog normal with renal disease. It is described graphic curve normal proteinuria, glomerular proteinuria, tubular proteinuria.
Aperçus nouveaux sur l'écologie du bacille de Whitmore
Authors: Dodin A.
Published: March 2018

L’écologie actuelle du bacille de Whitmore est caractérisée par une expansion presque mondiale du germe ou par un meilleur dépistage bactériologique du bacille.

La notion de «niche écologique» du bacille est devenue : «toute terre souillée et enrichie par des excréments contaminés». Il s’agit d’un germe essentiellement tellurique. Son pouvoir pathogène est fonction de l’inoculum de germes et du terrain.
Leadership Training in Graduate Medical Education: A Systematic Review
Authors: Sadowski Brett , Cantrell Sarah , Barelski Adam , O'Malley Patrick G. , Hartzell Joshua D.
Published: March 2018

Background 

Leadership is a critical component of physician competence, yet the best approaches for developing leadership skills for physicians in training remain undefined.

Objective 

We systematically reviewed the literature on existing leadership curricula in graduate medical education (GME) to inform leadership program development.

Methods 

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, we searched MEDLINE, ERIC, EMBASE, and MedEdPORTAL through October 2015 using search terms to capture GME leadership curricula. Abstracts were reviewed for relevance, and included studies were retrieved for full-text analysis. Article quality was assessed using the Best Evidence in Medical Education (BEME) index.

Results 

A total of 3413 articles met the search criteria, and 52 were included in the analysis. Article quality was low, with 21% (11 of 52) having a BEME score of 4 or 5. Primary care specialties were the most represented (58%, 30 of 52). The majority of programs were open to all residents (81%, 42 of 52). Projects and use of mentors or coaches were components of 46% and 48% of curricula, respectively. Only 40% (21 of 52) were longitudinal throughout training. The most frequent pedagogic methods were lectures, small group activities, and cases. Common topics included teamwork, leadership models, and change management. Evaluation focused on learner satisfaction and self-assessed knowledge. Longitudinal programs were more likely to be successful.

Conclusions 

GME leadership curricula are heterogeneous and limited in effectiveness. Small group teaching, project-based learning, mentoring, and coaching were more frequently used in higher-quality studies.
Quaternary tectonic activity of Maradona Fault System, Central Precordillera, Argentina
Authors: Lara Ferrero Gabriela , Perucca Laura , Rothis Martin , Pantano Ana , Saez Mauro
Published: March 2018

Several parallel east verging thrusts with Quaternary tectonic activity have been identified in the eastern piedmont of Cordón de Las Osamentas, Central Precordillera of Argentina. We grouped these structures into the Maradona Fault System (MFS). The main morphostructural units, called mountainous and transitional, were analyzed. The form and evolution of these units are closely related to the geological structure of the area. With the morphotectonic analysis, we estimated the length of MFS and the affected alluvial levels. Besides, the morphology of the escarpments was determined through detailed transversal topographic profiles made in a sector where the alluvial levels are affected by the faults. This analysis allowed the recognition of several fault segments and the selection of the points that would present the best natural exposures of the fault- sedimentary deposits relationships. Topographic profiles performed with differential GPS let to identify centimetric fault scarps through slope changes observed in each transect orthogonal to the direction of the structures. Five natural exposures were identified allowing determination of the kinematics of the different fault sections and the deposits affected by these structures. In all the analyzed exposures, faults are reverse with low angle (thrust), dipping to the west and affecting Neogene deposits and alluvial units assigned to the late Pleistocene-Holocene. The Maradona fault system affects younger alluvial levels to the east, showing the gradual migration of the Andean deformation eastward. The progression of the deformation in this sector of Central Precordillera would have evolved according to a pattern of thrusts with angles in surface near 45°, with sequences of internal deformation and reactivation during the Pleistocene-Holocene. Finally, the SFM is regarded as a potential seismogenic source capable to produce earthquakes with magnitude >Mw 6 and hit the main populated centers of the province of San Juan (>700,000 inhabitants), and several dams built along the San Juan River.
Caracterización sedimentológica de un Sistema Fluvial Distributivo de clima árido: arroyo Papagayos, en el piedemonte oriental de las Sierras La Huerta-Imanas, San Juan, Argentina
Authors: Santi Malnis Paula , Colombi Carina E. , Rodríguez-Posatini Natalia G. , Rothis Luis M. , Limarino Carlos O.
Published: March 2018

Recent studies proposed that distributive fluvial systems (DFS) occupy a great proportion in modern continental sedimentary basins, challenging classical sedimentary models proposed for similar ancient basin. Because of this, arises the importance of studying modern DFS with the aim of obtaining facial models to apply them in ancient deposits. In this paper, we analyze and discuss the sedimentary environments included in the modern deposits of the Arroyo Papagayos, Western Pampean Ranges, San Juan province, interpreted as a Distributive Fluvial System (DFS). We perform the study of the Papagayos creek by describing different architectural elements, which characterize the sub-environments organized in four zones from the mountain front to the distal playa lake. A low sinuosity gravelly-sandy bed braided fluvial system, characterizes the proximal zone. A medial to high sinuosity sandy-gravelly anastomosed-anabranching fluvial system describes the medial zone, where floodplain aggradation is domain by crevasse splays accretion. At this point, 10 km far from the mountain front, the deposits starts to develop a cone shaped morphology. A higher sinuosity flashy ephemeral meandering sandy-muddy fluvial system with eolian interaction defines the distal zone, where the main channel of the system disappears by low gradient of the topography and infiltration depositing muddy terminal splays. Finally, eolian dune and wet interdune deposits characterizes the fourth zone, interpreted as a transitional area between the DFS and the saline playa lake. A particular feature observed along the DFS system is that mudflows are the main sedimentary process in the floodplain, probably as the result of the combination of the seasonal arid climate and the Arroyo Papagayos drainage basin morphometry and the low gradient of the topography. The sedimentary process and environments recognized along the Arroyo Papagayos will allow a better understanding of arid DFS depositional dynamics as well as, to identify them in the geological record. Lastly, high aggrading conditions for DFS development will response to climate interaction between upland catchment area (semiarid) and valley (arid), drainage basin morphometry, smooth piedmont gradient and high tectonic subsidence of the basin, located in the Andean broken foreland.
Bioestratigrafía y provincialismo de conodontes del tramo medio-superior de la Formación San Juan en el cerro Viejo de Huaco, Precordillera, Argentina
Authors: Mango Matías J. , Albanesi Guillermo L.
Published: March 2018

The present study deals with the conodont biostratigraphy from the middle and upper parts of the San Juan Formation (Lower-Middle Ordovician) exposed at the Los Gatos creek section, west of the cerro Viejo de Huaco, Central Precordillera of San Juan Province. The numerous conodonts recovered, corresponding to 55 species, allow to recognize a series of biozones in the studied section. The biostratigraphic analysis carried out herein allows determining associations of conodonts assignable to the Oepikodus evae, Oepikodus intermedius, Baltoniodus triangularis-Tripodus laevis and Lenodus variabilis zones that correspond to the middle Floian to lower Darriwilian. The Baltoniodus navis and Microzarkodina parva zones were not identified due to insufficient information provided by this stratigraphic section. In general, the levels corresponding to the Baltoniodus triangularis-Tripodus laevis Zone contain more conodonts, than the records of other localities from Precordillera. These specimens are well preserved with a color alteration index (CAI) of 2-2.5, indicating overburden paleotemperatures ranging from 60° and 155° C. The large presence of fragmented conodonts, with recrystallized surfaces and crystal overgrowth, could indicate the effect of distinctive diagenetic fossil processes on the bearer limestone. The analysis of the diversity and abundance of genera and species of conodonts by chronostratigraphic intervals presents a great percentage of cosmopolitan taxa, 18% and 38% in common, at species level, only with the North-American Midcontinent Province (NAMP), and with a small percentage with the North-Atlantic Province (NAP) and the Precordillera, which allows to approximate a greater paleobiogeographic affinity of the conodonts recovered with those of the NAMP than those of the NAP for the entire interval studied. On the other hand, the Precordillera is verified as a province with its own characteristics as identified by several authors.
Identidades en transición: Prensa, activismo y disidencia sexual en Chile, 1990-2010
Authors: Garrido Juan Carlos , Barrientos Claudio Javier
Published: March 2018

La transición a la democracia significó la puesta en escena y espacio público de las temáticas de diversidad y disidencia sexual. En los años noventa y 2000, las ONGs y organizaciones de la diversidad sexual experimentaron los problemas del debilitamiento de las organizaciones civiles como consecuencia de la cooptación estatal que significaron las políticas de género y VIH-Sida, implementadas por los gobiernos de la Concertación de Partidos por la Democracia. Este artículo propone un análisis histórico de los debates en torno a la despenalización de la Sodomía, la ley de anti-discriminación y el VIH Sida, y cómo se abordaron desde la prensa nacional-oficial y en los medios de difusión propios del activismo homosexual, colocando atención en las representaciones, estereotipos y construcciones de género que circularon en la esfera pública nacional entre 1990 y 2010.
Light absorption by polar and non-polar aerosol compounds from laboratory biomass combustion
Authors: Sengupta Deep , Samburova Vera , Bhattarai Chiranjivi , Kirillova Elena , Mazzoleni Lynn , Iaukea-Lum Michealene , Watts Adam , Moosmüller Hans , Khlystov Andrey
Published: March 2018

Abstract. Fresh and atmospherically aged biomass-burning (BB) aerosol mass is mostly comprised of black carbon (BC) and organic carbon (OC) with its light-absorbing fraction – brown carbon (BrC). There is a lack of data on the physical and chemical properties of atmospheric BB aerosols, leading to high uncertainties in estimates of the BB impact on air quality and climate, especially for BrC. The polarity of chemical compounds influences their fate in the atmosphere including wet/dry deposition and chemical and physical processing. So far, most of the attention has been given to the water-soluble (polar) fraction of BrC, while the non-polar BrC fraction has been largely ignored. In the present study, the light absorption properties of polar and non-polar fractions of fresh and aged BB emissions were examined to estimate the contribution of different-polarity organic compounds to the light absorption properties of BB aerosols. In our experiments, four globally and regionally important fuels were burned under flaming and smoldering conditions in DRI’s combustion chamber. To mimic atmospheric oxidation processes (5–7 days), BB emissions were aged using an oxidation flow reactor (OFR). Fresh and OFR-aged BB aerosols were collected on filters and extracted with water and hexane to study absorption properties of polar and non-polar organic species. Spectrophotometric measurements over the 190 to 900 nm wavelength range showed that the non-polar (hexane-soluble) fraction is 2–3 times more absorbing than the polar (water-soluble) fraction. However, an increased absorbance was observed for the water extracts of oxidized/aged emissions while the absorption of the hexane extracts was lower for the aged emissions. Comparing the absorption Ångström Exponent (AAE) values, we observed changes in the light absorption properties of BB aerosols with aging that was dependent on the fuel types. The light absorption by HUmic LIke Substances (HULIS) was found to be higher in fuels characteristic of the southwestern USA. The absorption of the HULIS fraction was lower for OFR-aged BB emissions. Comparison of the light absorption properties of different polarity extracts (water, hexane, HULIS) provides insight into the chemical nature of BB BrC and its transformation during oxidation processes.
East Asian dust storm in May 2017: observations, modelling and its influence on Asia-Pacific region
Authors: Zhang Xiao-Xiao , Sharratt Brenton , Liu Lian-You , Wang Zi-Fa , Pan Xiao-Le , Lei Jia-Qiang , Wu Shi-Xin , Huang Shuang-Yan , Guo Yu-Hong , Li Jie , Tang Xiao , Yang Ting , Tian Yu , Chen Xue-Shun , Hao Jian-Qi , Zheng Hai-Tao , Yang Yan-Yan , Lyu Yan-Li
Published: March 2018

Abstract. A severe dust storm event originated from the Gobi Desert in Central and East Asia during 2–7 May, 2017. Based on moderate resolution imaging spectroradiometer (MODIS) satellite products, hourly environmental monitoring measurements from 367 Chinese cities and more than 2000 East Asian meteorological observation stations, and numerical simulations, we analysed the spatial and temporal characteristics of this dust event as well as its associated impact on the Asia-Pacific region. The maximum observed hourly PM10 (particulate matter with an aerodynamic diameter ≤ 10 μm) concentration was above 1000 μg m−3 in Beijing, Tianjin, Shijiazhuang, Baoding, and Langfang and above 2000 μg m−3 in Erdos, Hohhot, Baotou, and Alxa in northern China. This dust event affected over 8.35 million km2, or 87 % of mainland China, and significantly deteriorated air quality in 316 cities of the 367 cities examined across China. The maximum surface wind speed during the dust storm was 23–24 m s−1 in the Mongolian Gobi Desert and 20–22 m s−1 in central Inner Mongolia, indicating the potential source regions of this dust event. Lidar-derived vertical dust profiles in Beijing, Seoul, and Tokyo indicated dust aerosols were uplifted to an altitude of 1.5–3.5 km whereas simulations by the Weather Research and Forecasting with Chemistry (WRF-Chem) model indicated 20.4 Tg and 5.3 Tg of aeolian dust being deposited respectively across continental Asia and the North Pacific Ocean. According to forward trajectory analysis by the FLEXible PARTicle dispersion (FLEXPART) model, the East Asian dust plume moved across the North Pacific within a week. Dust concentrations decreased from East Asian continent across the Pacific Ocean from a magnitude of 103 to 10−5 μg m−3, while dust deposition intensity ranged from 104 to 10−1 mg m−2. This dust event was unusual due to its impact on continental China, Korea, Japan and North Pacific Ocean. Asian dust storms such as observed in early May 2017 may lead to wider climate forcing on a global scale.
On the role of aerosols, humidity, and vertical wind shear in the transition of shallow to deep
convection at the Green Ocean Amazon 2014/5 site
Authors: Chakraborty Sudip , Schiro Kathleen A. , Fu Rong , Neelin J. David
Published: March 2018

Abstract. The preconditioning of the atmosphere for a shallow-to-deep convective transition during the dry-to-wet season transition period (August–November) is investigated using Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) GoAmazon2014/5 campaign data from March 2014 to November 2015 in Manacapuru, Brazil. In comparison to conditions observed prior to shallow convection, anomalously high humidity in the free troposphere and boundary layer is observed prior to a shallow-to-deep convection transition. An entraining plume model, which captures this leading dependence on lower-tropospheric moisture, is employed to study indirect thermodynamic effects associated with vertical wind shear (VWS) and cloud condensation nuclei (CCN) concentration on pre-convective conditions. The shallow-to-deep convective transition primarily depends on humidity, especially that from the free troposphere, which tends to increase plume buoyancy. Conditions preceding deep convection are associated with high relative humidity, and low-to-moderate CCN concentration (less than the 67th percentile, 1274 cm−3). VWS, on the other hand, shows little relation to moisture and plume buoyancy. Buoyancy estimates suggest that the latent heat release due to freezing is important to deep convective growth under all conditions analyzed, consistent with potential pathways for aerosols effects, even in presence of a strong entrainment. Shallow-only convective growth, on the other hand, shows an association with a strong (weak) low (deep) level VWS and with higher CCN concentration.
Ideas and perspectives: hydrothermally driven redistribution and sequestration of early Archaean biomass – the “hydrothermal pump hypothesis”
Authors: Duda Jan-Peter , Thiel Volker , Bauersachs Thorsten , Mißbach Helge , Reinhardt Manuel , Schäfer Nadine , Van Kranendonk Martin J. , Reitner Joachim
Published: March 2018

Abstract. Archaean hydrothermal chert veins commonly contain abundant organic carbon of
uncertain origin (abiotic vs. biotic). In this study, we analysed kerogen
contained in a hydrothermal chert vein from the ca. 3.5 Ga Dresser
Formation (Pilbara Craton, Western Australia). Catalytic hydropyrolysis
(HyPy) of this kerogen yielded n-alkanes up to n-C22, with a sharp
decrease in abundance beyond n-C18. This distribution
(≤ n-C18) is very similar to that observed in HyPy products of
recent bacterial biomass, which was used as reference material, whereas it
differs markedly from the unimodal distribution of abiotic compounds
experimentally formed via Fischer–Tropsch-type synthesis. We therefore
propose that the organic matter in the Archaean chert veins has a primarily
microbial origin. The microbially derived organic matter accumulated in
anoxic aquatic (surface and/or subsurface) environments and was then
assimilated, redistributed and sequestered by the hydrothermal fluids
(“hydrothermal pump hypothesis”).
A comparison of methods to estimate vertical land motion trends from GNSS and altimetry at tide gauge stations
Authors: Kleinherenbrink Marcel , Riva Riccardo , Frederikse Thomas
Published: March 2018

Abstract. Tide gauge (TG) records are affected by vertical land motion (VLM), causing them to observe relative instead of geocentric sea level. VLM can be estimated from global navigation satellite system (GNSS) time series, but only a few TGs are equipped with a GNSS receiver. Hence, (multiple) neighboring GNSS stations can be used to estimate VLM at the TG. This study compares eight approaches to estimate VLM trends at 570 TG stations using GNSS by taking into account all GNSS trends with an uncertainty smaller than 1 mm yr−1 within 50 km. The range between the methods is comparable with the formal uncertainties of the GNSS trends. Taking the median of the surrounding GNSS trends shows the best agreement with differenced altimetry–tide gauge (ALT–TG) trends. An attempt is also made to improve VLM trends from ALT–TG time series. Only using highly correlated along-track altimetry and TG time series reduces the SD of ALT–TG time series by up to 10 %. As a result, there are spatially coherent changes in the trends, but the reduction in the root mean square (RMS) of differences between ALT–TG and GNSS trends is insignificant. However, setting correlation thresholds also acts like a filter to remove problematic TG time series. This results in sets of ALT–TG VLM trends at 344–663 TG locations, depending on the correlation threshold. Compared to other studies, we decrease the RMS of differences between GNSS and ALT–TG trends (from 1.47 to 1.22 mm yr−1), while we increase the number of locations (from 109 to 155), Depending on the methods the mean of differences between ALT–TG and GNSS trends vary between 0.1 and 0.2 mm yr−1. We reduce the mean of the differences by taking into account the effect of elastic deformation due to present-day mass redistribution. At varying ALT–TG correlation thresholds, we provide new sets of trends for 759 to 939 different TG stations. If both GNSS and ALT–TG trend estimates are available, we recommend using the GNSS trend estimates because residual ocean signals might correlate over long distances. However, if large discrepancies ( > 3 mm yr−1) between the two methods are present, local VLM differences between the TG and the GNSS station are likely the culprit and therefore it is better to take the ALT–TG trend estimate. GNSS estimates for which only a single GNSS station and no ALT–TG estimate are available might still require some inspection before they are used in sea level studies.
Orbit-related sea level errors for TOPEX altimetry at seasonal to decadal timescales
Authors: Esselborn Saskia , Rudenko Sergei , Schöne Tilo
Published: March 2018

Abstract. Interannual to decadal sea level trends are indicators of climate variability
and change. A major source of global and regional sea level data is satellite
radar altimetry, which relies on precise knowledge of the satellite's orbit.
Here, we assess the error budget of the radial orbit component for the
TOPEX/Poseidon mission for the period 1993 to 2004 from a set of different
orbit solutions. The errors for seasonal, interannual (5-year), and decadal
periods are estimated on global and regional scales based on radial orbit
differences from three state-of-the-art orbit solutions provided by different
research teams: the German Research Centre for Geosciences (GFZ), the Groupe de
Recherche de Géodésie Spatiale (GRGS), and the Goddard Space Flight Center
(GSFC). The global mean sea level error related
to orbit uncertainties is of the order of 1 mm (8 % of the global mean sea
level variability) with negligible contributions on the annual and decadal
timescales. In contrast, the orbit-related error of the interannual trend is
0.1 mm yr−1 (27 % of the corresponding sea level variability) and might
hamper the estimation of an acceleration of the global mean sea level rise.
For regional scales, the gridded orbit-related error is up to 11 mm, and for
about half the ocean the orbit error accounts for at least 10 % of the
observed sea level variability. The seasonal orbit error amounts to 10 %
of the observed seasonal sea level signal in the Southern Ocean. At
interannual and decadal timescales, the orbit-related trend uncertainties
reach regionally more than 1 mm yr−1. The interannual trend errors account
for 10 % of the observed sea level signal in the tropical Atlantic and the
south-eastern Pacific. For decadal scales, the orbit-related trend errors are
prominent in a several regions including the South Atlantic, western North
Atlantic, central Pacific, South Australian Basin, and the Mediterranean Sea.
Based on a set of test orbits calculated at GFZ, the sources of the observed
orbit-related errors are further investigated. The main contributors on all
timescales are uncertainties in Earth's time-variable gravity field models and on
annual to interannual timescales discrepancies of the tracking station
subnetworks, i.e. satellite laser ranging (SLR) and Doppler
Orbitography and Radiopositioning Integrated by Satellite (DORIS).
A Bayesian Hierarchical Model for Glacial Dynamics Based on the Shallow Ice Approximation and its Evaluation Using Analytical Solutions
Authors: Gopalan Giri , Hrafnkelsson Birgir , Aðalgeirsdóttir Guðfinna , Jarosch Alexander H. , Pálsson Finnur
Published: March 2018

Abstract. Bayesian hierarchical modeling can assist the study of glacial dynamics and ice flow properties. This approach will allow glaciologists to make fully probabilistic predictions for the thickness of a glacier at unobserved spatio-temporal coordinates, and it will also allow for the derivation of posterior probability distributions for key physical parameters such as ice viscosity and basal sliding. The goal of this paper is to develop a proof of concept for a Bayesian hierarchical model constructed, which uses exact analytical solutions for the shallow ice approximation (SIA) introduced by Bueler et al. (2005). A suite of test simulations utilizing these exact solutions suggests that this approach is able to adequately model numerical errors and produce useful physical parameter posterior distributions and predictions. A byproduct of the development of the Bayesian hierarchical model is the derivation of a novel finite difference method for solving the SIA partial differential equation (PDE). An additional novelty of this work is the correction of numerical errors induced through a numerical solution using a statistical model. This error correcting process models numerical errors that accumulate forward in time and spatial variation of numerical errors between the dome, interior, and margin of a glacier.
Mechanisms leading to the 2016 giant twin glacier collapses, Aru range, Tibet
Authors: Gilbert Adrien , Leinss Silvan , Kargel Jeffrey , Kääb Andreas , Yao Tandong , Gascoin Simon , Leonard Gregory , Berthier Etienne , Karki Alina
Published: March 2018

Abstract. In northwestern Tibet (34.0° N, 82.2° E) near lake Aru Co, the entire ablation area of two glaciers (Aru-1 and Aru-2) suddenly collapsed on 17 July 2016 and 21 September 2016, respectively, and transformed into 68 and 83 106 m3 mass flows that ran out up to 7 km, killing nine people. The only similar event currently documented is the 2002 Kolka Glacier mass flow (Caucasus Mountains). Using climatic reanalysis, remote sensing and 3D thermo-mechanical modeling, we reconstructed in detail the glaciers' thermal regimes, thicknesses, velocities, basal shear stresses and ice damage prior to the collapse. We show that frictional change leading to the collapses occurred in the temperate areas of polythermal glacier structures and are not linked to thaw of cold based ice. The two glaciers experienced a similar stress transfer from predominant basal drag towards predominant lateral shearing in the later detachment areas and during the 5–6 years before the collapses, though with a high friction patch on Aru-2 tongue which is inexistent on Aru-1. The latter led to distinctly disparate behaviour making the development of the instability more visible for the Aru-1 glacier compared to Aru-2 through enhanced crevassing over a longer period and terminus advance. Field investigations reveal that those two glaciers are flowing on a soft, highly erodible, and fine-grained sedimentary lithology. We propose that specific bedrock lithology played a key role in the two Tibet, and also in the Caucasus gigantic glacier collapses documented to date by producing low bed roughness and large amount of till rich in clay/silt with low friction angle. The twin Aru collapses would have been driven by a failing substrate linked to increasing water pore pressure in the subglacial drainage system in response to recent increases of surface melting and rain.
Understanding the Problem of Practice: An Analysis of Professional Practice EdD Dissertations
Authors: Ma Vera Wei , Dana Nancy Fichtman , Adams Alyson , Kennedy Brianna L.
Published: March 2018

Investigating a “problem of practice” is a signature feature of the EdD dissertation. Yet, little is known about how doctoral students derive their problems, the nature of the problems they study, and the impact studying problems of practice has on students’ local contexts. The purpose of this study was to investigate EdD students’ problems of practice through document analysis of 28 dissertations completed in one EdD program at a large, research-intensive university. Findings revealed that problems are derived from doctoral students’ felt difficulties and real-world dilemmas in three main categories: supporting marginalized students, increasing the quality of educator professional development, and supporting novices’ entry into the profession. Furthermore, five generic themes that describe the types of impact dissertation studies had on students’ local contexts are reported. Based on findings, four guidelines to assist EdD students in deriving problems of practice are offered.
Estudios
Authors: Arredondo Erika
Published: March 2018

Número misceláneo 262
Measuring transit-oriented development (TOD) network complementarity based on TOD node typology
Authors: Huang Runjie , Grigolon Anna , Madureira Mafalda , Brussel Mark
Published: March 2018

Recent research on the assessment of transit-oriented development (TOD) has focused on individual transit nodes. However, we argue that having such a TOD level value is not sufficient to understand the role each transit node plays within a TOD network. In other words, a transit node may have a low performance when evaluating its individual TOD level, but it may serve an important role within the TOD network, for example, as a feeder node. In this paper, a TOD typology was developed based on built-form indicators to identify the roles different types of nodes play within the transit network and to discuss complementarity effects between TOD nodes within the TOD network. The study area is the Arnhem-Nijmegen city region in the Netherlands, which has a TOD network of 22 train stations. Results identified three types of roles: suburban residential, characterized by low population and job densities; urban residential, marked by low destination accessibility and low diversity of land-uses; and urban mixed core, which featured higher densities of jobs, population, and diversity of land uses. Based on the TOD typology, a correspondence analysis was conducted to measure the potential complementarity effect of the TOD network system, i.e., the extent to which nodes in different typologies can complement each other to strengthen the characteristics of the TOD as a network. The results illustrated that differentiation among the TOD nodes in terms of residential housing prices and building uses contributed to a more diversified offer in terms of activities and functions of the TOD region and indicates complementarity between stations. Thus, TOD should be assessed and planned in a network system perspective, with the understanding that the nodes are pieces that contribute to the performance of the network.
Socio-economic Impact of Traditional Technology of Charcoal Production in Kpaai District-Bong County Liberia
Authors: Oladeji Sunday Oladipo , Ologunwa Oluyemi Phillips , Tonkollie Bendu Too
Published: March 2018

Locally produced charcoal through traditional technology is a source of income to the inhabitants of Kpaai district, Bong-County, Liberia and this has invariably contributed significantly to the country Gross Domestic Product. Two sets of questionnaires were designed and administered randomly to eighty seven consumers and fifty five producers representing sample intensity of between 54-68% and 10-10.3% respectively in five communities among the clans of Waytuah and Wotola. Field observation and Interview data collected were descriptively analysed using SPSS 20. Three traditional earth kiln methods of charcoal production were identified among the producers that are mostly male (69.20-85.10%). Women representing 61.20-82.70% of the consumer in the age range of 21-30 years (36.4-71.40%) were spending between 13-25% of their income on charcoal. Producers have recorded various achievement from the income range of between LD5, 000-20,000 realized monthly. Dirty of their bodies and houses, sicknesses, generating smoke and ash dust were the forms of social economic impact being encountered. Research findings will assist Liberia Government in developing appropriate modern technology for efficient charcoal production and sustainable energy generation as part of REDD + implementation process.
Becoming Who You Are: Nietzsche on Self-Creation
Authors: Franco Paul
Published: March 2018

In this article, I examine Nietzsche's doctrine of self-creation as he develops it from Schopenhauer as Educator through Gay Science (GS). While many scholars have tackled this topic, they have generally focused on a few well-known snippets from Nietzsche's works without putting them in the context of Nietzsche's carefully wrought texts or philosophical development as a whole. Nietzsche's doctrine of self-creation receives its clearest articulation in GS IV, but in order to understand that doctrine fully, I trace its genesis in the writings leading up to GS. Doing so allows me to shed light on long-standing puzzles about Nietzsche's understanding of authenticity, the relationship between self-creation and his so-called fatalism, and the nature and limits of his commitment to the aesthetic model of the self.
Nietzsche's Ethics of Danger
Authors: Kuehne Tobias
Published: March 2018

Recent scholarship on Nietzsche's ethical naturalism has acknowledged that a better understanding of his ethics requires a fuller account of his paradoxical reasoning. Continuing this line of thought, this article establishes a fulcrum between Nietzsche's unconventional ethics and mode of argumentation by examining an overlooked motif in his thinking: danger. Danger is the threat of complacent thinking and entrenched belief systems disintegrating under their hidden self-contradictions. It emerges as a key concern in Nietzsche's early works and brings with it a persistent challenge to our thinking and our ethics; refusing to be deceived, we must live courageously by identifying the paradoxes that beset our knowledge and moral beliefs. In his middle works, Nietzsche takes on the persona of the intellectually honest free spirit that attacks any systematic metaphysics, and thus offers a dangerous proposition: an ethics is only possible (yet may still fall short) in moments when metaphysics collapses and paradox rears its head.
EFEITO DA MUDANÇA NA OCUPAÇÃO DO SOLO SOBRE O CLIMA DE PORTO VELHO, RONDÔNIA, BRASIL
Authors: Da Silva Marcelo José Gama , Querino Carlos Alexandre Santos , Dos Santos Neto Luiz Alves , Machado Nadja Gomes , Militão Julio Saches , Biudes Marcelo Sacardi
Published: March 2018

A região amazônica têm sido foco de discussões e estudo relacionando o uso e ocupação das terras com as mudanças climáticas locais. Esse trabalho tem como objetivo avaliar a influência das mudanças de uso e cobertura da terra sobre o clima da região de Porto Velho – RO. Utilizou-se séries temporais da temperatura do ar média, máxima e mínima, umidade relativa do ar e precipitação, do município de Porto Velho, entre 1945 a 2005. A mudança de uso e cobertura do solo foi avaliada através das informações geradas pelo Programa de Cálculo de Desflorestamento da Amazônia do INPE, entre 1988 a 2006 para Rondônia e Amazonas, e dados produzidos pela Secretaria de Estado do Desenvolvimento Ambiental, no período de 2000 a 2007 em Rondônia. Observou-se que a área de estudo apresentou desmatamento inferior ao mensurado no estado de Rondônia e superior ao do estado do Amazonas. A temperatura média do ar foi maior no período pré-colonização (1945 a 1970), do que no período de colonização (1971 a 1945). Evidenciou-se um aumento da temperatura média máxima do ar e redução da temperatura média mínima do ar no período de colonização (1971 a 2005) e de pré-colonização (1945 a 1970), respectivamente. A umidade relativa do ar apresentou uma tendência de redução no período de analise (1945 a 2005), sendo mais evidenciada após a década de 80. Os resultados observados indicam possíveis impactos do desmatamento no clima da Amazônia, mas os testes estatísticos não comprovam alterações climáticas significativas na região
A EVOLUÇÃO DA PAISAGEM DA REGIÃO CARBONÍFERA DO ESTADO DE SANTA CATARINA REALIZADO COM IMAGENS DE SATÉLITE
Authors: Ladwig Nilzo Ivo , Dagostim Vanessa , Back Alvaro José
Published: March 2018

A atividade de extração do carvão mineral, responsável em grande parte pelo desenvolvimento econômico do extremo sul do Estado de Santa Catarina, alterou significativamente a paisagem natural do território de diversos municípios por meio da contaminação dos recursos hídricos, do solo e pela poluição atmosférica com a geração de gases e poeira. O estudo objetivou caracterizar a evolução da paisagem da região carbonífera entre os anos de 1986 e 2016, por meio de análise de série multitemporal de imagens de satélite. A análise se deu por meio de mapas temáticos de uso e cobertura do solo obtidos pelo método de classificação supervisionada MAXVER (Máxima Verossimilhança). Os resultados demonstraram que o método de classificação possui limitações com relação à sua utilização, tendo sido mais eficaz para a identificação das áreas do que para a quantificação. Embora, tenha que se considerar as especificidades do funcionamento do algoritmo. Os dados de sensoriamento remoto permitiram a análise da evolução da paisagem entre os anos de 1986, 2006 e 2016, conferindo desta maneira, base para o planejamento e ordenamento do território.