bluuebunny/crossref_metadata_2025 huggingface dataset:
Édouard Fuster : de l’expertise à la science des villes
Authors: Vonau Elsa
Published: August 2019

Cet article s’inscrit dans le champ des recherches qui étudient l’institution de l’urbanisme comme discipline, à travers la diffusion, la codification et l’institutionnalisation des connaissances sur lesquelles se sont établies, au cours de la première moitié du XX e siècle, les pratiques de la planification urbaine. Afin d’ouvrir un aperçu sur les circonstances dans lesquelles l’enseignement de l’urbanisme s’est constitué, et la manière dont son objet a été défini, l’analyse se fonde sur la spécificité des cours professés par Édouard Fuster sur « L’organisation sociale des villes » dans le cadre de l’École des hautes études urbaines, puis de l’Institut d’urbanisme de l’Université de Paris à partir de 1924. En s’appuyant sur la trajectoire du réformateur dont la carrière a été partagée entre action réformatrice et pratique savante, le présent travail entend notamment éclairer le processus de transmutation à travers la ville, cadre et objet de l’action réformatrice, qui s’est constituée en objet de savoir.
L’impossible sociologie de la consommation dans les études rurales françaises
Authors: Laferté Gilles
Published: August 2019

Marquée par le modèle anthropologique à la recherche d’une culture paysanne en extinction, la boîte à outils de l’ethnologie et de la sociologie rurale dans le cas de la France a longtemps esquivé le vocabulaire de la consommation et de l’argent pour le réserver à l’étude des ouvriers et de la modernité. Cette approche nous semble caractéristique d’un sous-champ disciplinaire qui a construit un vocabulaire ad hoc pour l’analyse des paysans en dehors d’une approche en termes de classes sociales. Les pratiques de consommation sont alors lues principalement sous l’angle de rituels ou de tradition (la chasse, le jardinage…). Il faut attendre le déclin de la sociologie rurale et de sa conceptualisation pour retrouver une lecture en termes de classe sociale ou de groupe socioprofessionnel et envisager une possible sociologie de la consommation.
Céline Lhotte, Élisabeth Dupeyrat, « La préparation du futur foyer de la jeune travailleuse ». Restitution d’une enquête de la Jeunesse ouvrière chrétienne féminine (1937)
Authors: Chessel Marie-Emmanuelle , Egea Anna
Published: August 2019

Dans les années 1930, deux assistantes sociales, Céline Lhotte et Elisabeth Dupeyrat, publient des articles puis un ouvrage à partir de résultats d’enquêtes réalisées par la Jeunesse ouvrière chrétienne féminine, sur le thème de « la préparation au mariage ». Ce document est un extrait de ces publications, parues dans les Dossiers de l’Action Populaire . Il est introduit par un commentaire mettant en évidence les pratiques d’enquêtes de la JOCF, le rôle des assistantes sociales dans leur diffusion et l’intérêt de relire ces documents aujourd’hui.
L’École sous le Protectorat tunisien, un terrain d’expérimentation de l’Éducation nouvelle ? Transferts et passages dans la trajectoire de Marie-Anne Carroi
Authors: Fontaine Alexandre , Riondet Xavier
Published: August 2019

L’originalité de cette contribution est d’aborder le processus de conversion de l’École Républicaine aux idées de l’Éducation Nouvelle à travers le contexte global de circulation de l’Empire colonial français. Cet article porte en effet sur la déclinaison coloniale de l’École Républicaine et la manière dont des acteurs de la pédagogie ont trouvé dans ce cadre une opportunité pour élaborer des expérimentations pédagogiques. Nous abordons plus particulièrement cette question par l’étude de la trajectoire de Marie-Anne Carroi, figure oubliée mais fondamentale des réseaux francophones de l’Éducation Nouvelle pendant l’Entre-deux-Guerres. Dans cette perspective, nous mettons en évidence comment des idées de l’Éducation Nouvelle ont été diffusées et (ré)appropriés pour être mises en pratiques dans le cadre du Protectorat tunisien, à travers des transferts pédagogiques singuliers dans des conjonctures sociales et politiques complexes.
Les regroupements d’établissements dans l’enseignement supérieur et la recherche : enjeux politiques et cadrage juridique
Authors: Guiselin Emmanuel-Pie
Published: August 2019

Les regroupements dans l’enseignement supérieur et la recherche ont pris une dimension nouvelle depuis la loi Goulard de 2006. Il s’est agi, en effet, pour les pouvoirs publics, de répondre à de forts enjeux politiques (le développement d’une politique de site en premier lieu) en concevant des cadres légaux à même d’accueillir, à une échelle pertinente, universités, écoles et organismes de recherche. Pour les acteurs de l’enseignement supérieur et de la recherche, le choix du type de regroupement, ainsi que son organisation, en fonction de leurs besoins et des outils juridiques, est essentiel : en dépendent la pertinence, l’efficience, et donc la légitimité du regroupement.
Quel usage de l’entretien professionnel dans la gestion du personnel administratif des universités ?
Authors: Pierronnet Romain
Published: August 2019

En 2007, la loi relative aux libertés et responsabilités des universités ambitionnait de renforcer l’autonomie des universités françaises. Plus de dix ans après, dans quelle mesure peut-on considérer que les universités gèrent leurs ressources humaines de manière autonome ? Pour en discuter, nous proposons d’étudier le dispositif de l’entretien professionnel s’appliquant aux personnels administratifs et techniques des établissements. En effet, de sa conception à son utilisation par les responsables des ressources humaines, l’entretien est le révélateur de différents paradoxes et rend compte des limites de l’autonomie réelle des universités françaises en la matière.
Searching the Literature in Preparation for Research: Strategies That Matter
Authors: Spurlock Darrell
Published: August 2019

Literature searches conducted in preparation for a study differ in both purpose and scope from the literature searches conducted to locate evidence relevant to specific, narrowly defined clinical or educational practice questions. In this Methodology Corner installment, several important considerations are reviewed, including the importance of understanding the scope and coverage of literature databases, the utility of database search fields and controlled vocabularies, search limiters and expanders, and the possible unintended consequences of limiting searches based on the availability of full-text resources. Examples are provided throughout to help nursing education researchers conduct more effective and efficient literature searches.

[
J Nurs Educ.
2019;58(8):441–443.]
Transformative Learning in an Online Doctor of Nursing Practice Population Health Course
Authors: McKinney Selina Hunt , Herman JoAnne , Nkwonta Chigozie A.
Published: August 2019

Background:

Population health is a critical component of Doctor of Nursing Practice (DNP) education, providing the foundation for clinical prevention, health equity, responsible policy, and practice change. Many DNP learners enter population health courses focused on individual patient care in microsystems. Transformative learning broadens learners' perspectives about health determinants and implications for health system transformation.

Method:

Transformative learning strategies were imbedded in a 10-week, online population health course. Students engaged with readings and multimedia content and wrote anonymous reflective analyses about population health determinants. Qualitative survey data were explored for transformative content using line-by-line content analysis. The stages of transformative learning were used as a priori codes.

Results:

Learners questioned their own beliefs and epistemologies and demonstrated all aspects of transformative learning, although not equally across course topics.

Conclusion:

To achieve the promised outcomes of DNP education, population health content should be professionally transformative and integrated across the curriculum.

[
J Nurs Educ.
2019;58(8):481–484.]
Stochastic games with hidden states
Authors: Yamamoto Yuichi
Published: August 2019

This paper studies infinite‐horizon stochastic games in which players observe actions and noisy public information about a hidden state each period. We find a general condition under which the feasible and individually rational payoff set is invariant to the initial prior about the state when players are patient. This result ensures that players can punish or reward their opponents via continuation payoffs in a flexible way. Then we prove the folk theorem, assuming that public randomization is available. The proof is constructive and uses the idea of random blocks to design an effective punishment mechanism.
Fully Automated Classroom Attendance System
Authors: Al Hajri Eid , Hafeez Farrukh , N V Ameer Azhar
Published: August 2019

This paper is based on study and implementation of the pilot project for customized, automated, highly secured class room management system known as JIC CMS (Jubail Industrial College Class room management System). In this research paper, the strategies, design, development and implementation of a pilot project for class room attendance management systems is explained in detail. As a pilot project, mobile app is built on Android platform using Xamarin programming. Prototype of proposed system provides high level of authentication by embedding face recognition and biometric verification together with RFID system.  Though given model features are specially designed for our college needs, but this model can be modified for general usage and can be applied for all academic levels i.e. school, college, universities. Among the other features of system, one important feature is selection of system to work in smart mode in which system closes after predefined time and uploaded automatically to the web server.
The Effect of Mobile Digital Content Applications Based on Gamification in the Development of Psychological Well-Being
Authors: Alhalafawy Waleed Salim , Zaki Marwa Zaki
Published: August 2019

The aim of this research is to design a proposed model for Mobile Digital Content Applications Based on Gamification and measure its effectiveness in the development of psychological well-being among the graduate students of King Abdulaziz University who are challenged with issues related to the nature of postgraduate studies, which may affect their levels of psychological well-being. Research sample consisted of (62) students, particularly those who are students of the postgraduate programs at King Abdulaziz University. The study has applied the semi-experimental approach that is based on two group design. The experimental group used an application version called "My Academic Advisor", which was developed according to the proposed model, while the control group used a version that did not include any methods or tools for gamification. A measure of psychological well-being was built through the mobile digital content applications. The measure in its final version consisted of 6 themes that included (36) indicators of psychological well-being; 6 indicators for each theme. The results of the application showed the effectiveness of the proposed model of the gamification in the development of psychological well-being among the experimental group students compared to the students of the control group.
Effect of UHMWPE Fiber Laminate on Effective Protection Area of Ceramic Composite Target
Authors: Gao Song , Chen Bin
Published: August 2019

In order to study the effect of UHMWPE fiber laminate on effective protection area of ceramic composite target, a dynamic analysis software ANSYS/LS-DYNA was used to calculate the effective protection area of ceramic/aluminum/aluminum composite target and ceramic/UHMWPE/aluminum/ aluminum composite target, both of whose areal density were 139.5kg/m2, against 14.5mm armor piercing projectile at the speed of 1000m/s. The result showed that UHMWPE fiber laminates will increase the effective protection area by 64.4% for ceramic composite targets under the same areal density.
Investigation on Torsion Stiffness of Thick-Walled Composite Hollow Shaft
Authors: Yang Mo , Zhou Xian , Zhang Wen
Published: August 2019

A non-classical mechanical analysis method was used to derive the equivalent torsional stiffness  of thick-walled CFRP drive shaft. The equivalent shear modulus calculated by classical lamination theory, finite element analysis method and non-classical mechanical analysis method were compared. Experimental work was carried out on six composite tubes made of same dimensions but different lay-ups. All the results show that the layers with ±45° fiber orientation angle located on the outside of the wall thickness can increase the torsion stiffness of the composite tube. The non-classical mechanical analysis method predicts the torsion stiffness of thick-walled composite tube more precisely than the theory classical lamination, and agree well with experimental results. This method provides a convenient, accurate and fast method for the torsion stiffness.
The Effect of Cold Isostatic Pressing on the Microstructure and Properties of Aluminium Matrix Composite Reinforced with Nano/Micro SiC Particles
Authors: Gao Hong Xia , Wang Meng , Fan Jiang Lei , Wu Shen , Wang Yan , Li Ying
Published: August 2019

Nano sized of 4wt.% and micro sized of 15wt.% SiC particles reinforced aluminum mental matrix composites fabricated by powder metallurgy vacuum hot pressing sintering were treated by cold-isostatic pressing. The effects of cold isostatic pressing on microstructure, density, hardness and wear resistance were investigated and analyzed. The experimental results showed that in the composites reinforced with hybrid SiC particles after cold isostatic pressing treatment, the agglomeration phenomenon and overlap phenomenon around the micron SiC particles disappeared and the surrounding defects were obviously improved, the grains were flattened, and the material was more densely. The composite is characterized by abrasive wear.
Female calling behaviour in the Asian longhorned beetle (Coleoptera: Cerambycidae)
Authors: Xu Tian , Hansen Laura , Teale Stephen A.
Published: August 2019

Female Asian longhorned beetles,Anoplophora glabripennis(Motschulsky) (Coleoptera: Cerambycidae), were observed rhythmically extruding their genitalia, resembling the calling behaviour observed in other species of Cerambycidae. We demonstrate that only femaleA.glabripennisadults perform this behaviour, which lasts up to nearly six minutes and typically includes two types: (1) extrusion of only the tip of genitalia and (2) genitalia fully extruded and deflexed. The frequency and duration of this behaviour are affected by temperature and posteclosion feeding experience, but do not vary with the female age.Anoplophora glabripennisadult males were observed flexing their abdomen downward while extruding their genitalia but only when exposed to the odour of live females with host twigs. In Y-tube olfactometer assays, the volatiles from live females or female genital extracts both attracted more males than the volatiles from live males, male genital extracts, or solvent controls, all in the presence of host-plant volatiles. These findings indicate thatA.glabripennisfemales may produce volatile sexual attractants in association with genital extrusion.
Host body size and the abundance of chewing lice (Phthiraptera: Amblycera, Ischnocera) infesting eight owl species (Aves: Strigiformes) in Manitoba, Canada
Authors: Lamb Robert J. , Galloway Terry D.
Published: August 2019

Specimens (n = 508) of eight species of owl (Aves: Strigiformes) collected from 1994 to 2017 in Manitoba, Canada, were weighed and examined for chewing lice (Phthiraptera: Amblycera, Ischnocera). The relationship between host body mass and infestation by 12 species of lice was examined. Host body mass explained 52% (P = 0.03) of the variation in mean intensity of louse infestation among hosts, due primarily to a high abundance of lice on the heaviest owl species. The relationship was due to the mean intensity of lice, and neither species richness nor the prevalence of lice was related to host body mass. For individual louse species, the relationship was due primarily to Kurodaia acadicae Price and Beer, Kurodaia magna Emerson, and an undetermined species of Kurodaia Uchida (Phthiraptera: Menoponidae) (R2 = 0.997), but not the nine Strigiphilus Mjöberg (Phthiraptera: Philopteridae) species (R2 = 0.27). Louse intensity did not increase with body size for individual birds of any of the owl species. Mean intensity is expected to increase in proportion with the size, specifically the surface area, of the host. Why that relationship holds only for one louse genus, and not for the most abundant genus of lice on owls, and weakly compared with other families of birds, has yet to be determined.
Master World Records show minor gender differences of performance decline with aging
Authors: Gava Paolo , Ravara Barbara
Published: August 2019

Aging behaviours are significantly different in females and males, e.g., the former have a longer life expectancy, but consistently a weaker muscle force. Our purpose is to analyse possible gender-differential declines of skeletal muscle performance. The method to find out the decline of performances with aging is based on a parametric analysis of the World Records of Master athletes in different Track and Field events. The analysis is a transformation (normalization) of sports results into dimensionless parameters ranging from the maximum value of 1 (for the absolute world record) to decreasing values with decreasing performances. Master athletes compete in age groups of 5 years till the age of 100 years, thus their World Records are lists of up to 16 data. Results of the normalization procedure are trend-lines indicating that the decline starts not later than the age of thirty years for both women and women. The decline with aging of the muscle performances indicates only minor gender differences in the aging process and all trend-lines tend to zero at about the age of 110 years. The approach, making use of a homogeneous cohort of testers, gets rid of the main confounding factors biasing other kind of studies of the muscle performance decline with aging, in particular clinical studies. Comparing normalized female and male World Records of Master athletes, a surprise emerged: aging decline is very similar, if not identical, the unique exception to the general rule of gender differences in sports activities. The substantial identity of decline trends among females and males suggests that neuro-hormonal differences among genders poorly influence the aging decline, being conceivably related to fundamental cell bioregulators, such as those of cellular energy metabolism and/or their epigenetic regulatory mechanisms.
Esterase profiling and molecular identification of yeasts isolated from different environmental samples from Morocco
Authors: El Aamri Lamya , Scordino Fabio , Barresi Cinzia , Romeo Orazio , Criseo Giuseppe , Hafidi Majida
Published: August 2019

One hundred and six fungal strains were isolated from different environmental samples (fresh olive oil cake, exhausted olive oil cake, black olive, rancid butter samples, rotten bread and Roquefort) collected from the region of Meknes, Morocco (coordinates: 33°53′42″N 5°33′17″W). Yeast isolates were tested for their esterase production ability using a qualitative method based on Tween agar plate assay. Enzymatic activity was also confirmed by a quantitative method relying on esterase production in liquid medium (6 days at 28°C with shaking). Molecular characterization of the selected esterase-producing yeasts was performed by sequencing the internal transcribed spacer 1 (ITS1), 5.8S and ITS2 region of the rDNA. A total of five different species were identified in this study: Candida aaseri (LE.26, LE.27 and LE.31 strains), Wickerhamomyces anomalus (LE.106, LE.112 and LE.115 strains), Metschnikowia rancensis (LE.153 strain), Pichia sp., (LE.102) and Rhodotorula mucilaginosa (LE.171 strain). Esterase production in C. aaseri and W. anomalus was found to be straindependent, while for M. rancensis this represents the first study reporting this species as an esterase producer.
Effectivity of topical mangosteen pericarp extract cream on wound healing in Swiss albino mice
Authors: Sombolayuk Hilda Brigitta , Djawad Khairuddin , Wahab Siswanto , Miskad Upik A. , Alam Gemini , Pattelongi Ilhamjaya
Published: August 2019

Wound healing is a complex physiological process consisting of four phases: coagulation, inflammation, proliferation and migration, and remodeling, each with distinct characteristics. Studies have suggested that mangosteen pericarp extract (MPE) may accelerate wound healing. However, the mechanism has not been fully understood. This study aims to evaluate the effect of MPE cream in various concentrations in acute wound healing of albino mice, both histologically and macroscopically. Thirty-two healthy female Swiss albino mice, aged 6-9 weeks, weight 20-30 g, were included in this study. The samples were randomly divided into eight groups each consisting of 4 mice. The first four groups were treated with MPE cream 5%, 10%, and 20%, and no medication (control group), respectively, and were sacrificed after three days. The other four groups received the same application and were sacrificed after 8 days. Wound bed diameter was measured and biopsy from the skin lesion was performed for histopathologic examination. Mann-Whitney test was used to analyze the diameter of the wound bed and histopathological findings of granulation tissue formation, reepithelialization, and inflammation, with P<0.05 considered as significant. MPE cream significantly improved wound healing by increasing granulation tissue formation, and reepithelialization. In addition, MPE cream application was also shown to decrease the number of inflammatory cells, particularly in 5% and 10% concentrations, both in the 3-day and 8-day groups. MPE cream application can accelerate wound healing and thus can be used in acute wound treatment.
Early recurrent otitis media, language and central auditory processing in children
Authors: Campbell Nicci , Hugo René , Uys Isabel , Hanekom Johan J. , Millard Solly
Published: August 2019

The study examines the relationships that exist between early recurrent otitis media, language and central auditory processing in children. A retrospective case-control experimental design was employed and ten subjects were allocated to each of the two research groups, namely children with a history of early recurrent otitis media (research group 1) and children without a history of early recurrent otitis media (research group 2). The children in both research groups were in grade one and turning 7 years old. The language and central auditory processing of the subjects were assessed using the Clinical Evaluation of Language Function (Wiig & Semel, 1980) and the Willeford Battery of Central Auditory Function (Willeford, 1974). The results showed that the language and central auditory processing of the children with a history of early recurrent otitis media were significantly poorer than that of their disease-free peers. The results stress the importance of vigorous identification and management programmes for children with a history of early recurrent otitis media.
Excess cerumen: Failure rate of Black and Indian preschool children from Durban on the Middle Ear Screening Protocol (MESP)
Authors: Bhoola Daksha , Hugo René
Published: August 2019

The aim of the study was to examine the failure rate of Black and Indian subjects within the excessive cerumen category of the Middle Ear Screening Protocol (MESP). The subjects included four to five year old Black and Indian children attending pre-schools in the Durban Central Region. Thus, a sample of 728 subjects (average age = 4.6 years), 312 Black (135 male and 180 female) and 413 Indian (223 male and 190 female) was screened using referral criteria based on a Middle Ear Screening Protocol  (MESP). The results of the study indicated that a significant percentage of  Black (38,4%) and Indian (49,9%)  subjects failed, due to excessive cerumen. These results are discussed with reference to the literature. A cerumen management program has been outlined and recommended to be implemented in preschools in South Africa.
Predicting hearing loss from otoacoustic emissions using an artificial neural network
Authors: De Waal Rouviere , Hugo René , Soer Maggi , Krüger Johann J.
Published: August 2019

Normal and impaired pure tone thresholds (PTTs) were predicted from distortion product otoacoustic emissions (DP using a feed-forward artificial neural network (ANN) with a back-propagation training algorithm. The ANN used a present and absent DPOAEs from eight DP grams, (2fl -f2 = 406 - 4031 Hz) to predict PTTs at 0.5, 1, 2 and 4 kHz. With normal hearing as < 25 dB HL, prediction accuracy of normal hearing was 94% at 500, 88% at 1000, 88% at 2000 and 93% at 4000 Hz. Prediction of hearing-impaired categories was less accurate, due to insufficient data for the ANN to train on. This research indicates the possibility of accurately predicting hearing ability within 10 dB in normal hearing individuals and in hearing-impaired listeners with DPOAEs and ANNsfrom 500 - 4000 Hz.
The needs of teachers of children with hearing loss within the inclusive education system
Authors: Van Dijk Catherine , Hugo René , Louw Brenda
Published: August 2019

In South Africa, the current movement towards the inclusion of children with disabilities, including children with hearing loss, is likely to have far-reaching consequences for both teachers and learners. Undoubtedly, needs will arise from teachers during the transition, especially in the areas pertaining to the audiological and educational management of children with hearing loss. Therefore, a descriptive research design was developed comprising of a questionnaire survey followed by focus group interviews to determine teachers needs. The questionnaire survey explored the needs of 664 teachers while focus group interviews were conducted with 19 teachers of children with hearing loss. Teachers were mostly from special schools as only a very small number of children are educated outside these establishments. Findings revealed that, although participants realised the importance of various aspects of development of the child with hearing loss, they generally did not realise the importance of receiving support from an educational audiologist.
A framework for improving the quality of management information
Authors: Cilliers G. Le R. , De Jager H.
Published: August 2019

Computer-created information is rapidly becoming too great for executives and others to absorb. The quality of information must therefore be enhanced to provide business managers with appropriate information to make efficient decisions. This paper presents the findings of a study to clarify the main and supportive attributes of quality information and the computer tools that support the production of such information. The study presents a framework for the evaluation of the most appropriate computer equipment and applications that would lead to the improvement of information quality in a particular organisation.
Sector effect on working capital measures in South African industrial firms
Authors: Beaumont Smith Marolee
Published: August 2019

This paper reports research findings concerning the sector effect on working capital measures in South African industrial firms. Thirteen working capital measures were computed for each of the 135 participating firms over 10 years. The appropriate nonparametric statistical procedure, the Kruskal-Wallis test, was applied to the data to test the null hypothesis of no sector effect. The test inferred that there was a significant sector effect for 10 of the 13 working capital measures. However, when regulating for an overall 5 percent level of significance, less than half the tested measures registered a significant sector effect. These findings suggest that inter-industry differences in working capital measures in South Africa might not be as significant as claimed in previous local and international research findings.
Die strategiese bestuur van regstellende aksie in plaaslike regering in Suid Afrika
Authors: Brynard P. , Van Rooyen E.
Published: August 2019

The South African Government regards affirmative action as an important method to rectify the discriminatory career practices followed against Blacks, Coloureds, Indians and women under the previous political dispensation. Legislation and policy that provide for affirmative action in institutions have been formulated and are considered in this paper. After normative and empirical research, it is concluded that it is possible to develop strategic affirmative action programmes in local government institutions and that affirmative action can be managed in terms of a strategic process in local government. It is further concluded that managers in local governments playa key role in the successful implementation of strategic affirmative action programmes
Asymptotics of fast rotating density-dependent incompressible fluids in two space dimensions
Authors: Fanelli Francesco , Gallagher Isabelle
Published: August 2019

In the present paper we study the fast rotation limit for viscous incompressible fluids with variable density, whose motion is influenced by the Coriolis force. We restrict our analysis to two dimensional flows. In the case when the initial density is a small perturbation of a constant state, we recover in the limit the convergence to the homogeneous incompressible Navier–Stokes equations (up to an additional term, due to density fluctuations). For general non-homogeneous fluids, the limit equations are instead linear, and the limit dynamics is described in terms of the vorticity and the density oscillation function: we lack enough regularity on the latter to prove convergence on the momentum equation itself. The proof of both results relies on a compensated compactness argument, which enables one to treat also the possible presence of vacuum.
Variations in the vertical profile of ozone at four high-latitude Arctic sites from 2005 to 2017
Authors: Bahramvash Shams Shima , Walden Von P. , Petropavlovskikh Irina , Tarasick David , Kivi Rigel , Oltmans Samuel , Johnson Bryan , Cullis Patrick , Sterling Chance W. , Thölix Laura , Errera Quentin
Published: August 2019

Abstract. Understanding variations in atmospheric ozone in the
Arctic is difficult because there are only a few long-term records of
vertical ozone profiles in this region. We present 12 years of ozone
profiles from February 2005 to February 2017 at four sites: Summit Station,
Greenland; Ny-Ålesund, Svalbard, Norway; and Alert and Eureka, Nunavut, Canada.
These profiles are created by combining ozonesonde measurements with ozone
profile retrievals using data from the Microwave Limb Sounder (MLS). This
combination creates a high-quality dataset with low uncertainty values by relying
on in situ measurements of the maximum altitude of the ozonesondes
(∼30 km) and satellite retrievals in the upper atmosphere (up
to 60 km). For each station, the total column ozone (TCO) and the partial
column ozone (PCO) in four atmospheric layers (troposphere to upper
stratosphere) are analyzed. Overall, the seasonal cycles are similar at
these sites. However, the TCO over Ny-Ålesund starts to decline 2
months later than at the other sites. In summer, the PCO in the upper
stratosphere over Summit Station is slightly higher than at the other sites
and exhibits a higher standard deviation. The decrease in PCO in the middle
and upper stratosphere during fall is also lower over Summit Station. The
maximum value of the lower- and middle-stratospheric PCO is reached earlier
in the year over Eureka. Trend analysis over the 12-year period shows
significant trends in most of the layers over Summit and Ny-Ålesund
during summer and fall. To understand deseasonalized ozone variations, we
identify the most important dynamical drivers of Arctic ozone at each level.
These drivers are chosen based on mutual selected proxies at the four sites
using stepwise multiple regression (SMR) analysis of various dynamical parameters
with deseasonalized data. The final regression model is able to explain more
than 80 % of the TCO and more than 70 % of the PCO in almost all of the
layers. The regression model provides the greatest explanatory value in the
middle stratosphere. The important proxies of the deseasonalized ozone time
series at the four sites are tropopause pressure (TP) and equivalent latitude (EQL) at
370 K in the troposphere, the quasi-biennial oscillation (QBO) in the troposphere
and lower stratosphere, the equivalent latitude at 550 K in the middle and
upper stratosphere, and the eddy heat flux (EHF) and volume of polar stratospheric
clouds throughout the stratosphere.
Methane emissions from oil and gas platforms in the North Sea
Authors: Riddick Stuart N. , Mauzerall Denise L. , Celia Michael , Harris Neil R. P. , Allen Grant , Pitt Joseph , Staunton-Sykes John , Forster Grant L. , Kang Mary , Lowry David , Nisbet Euan G. , Manning Alistair J.
Published: August 2019

Abstract. Since 1850 the concentration of atmospheric methane (CH4), a potent
greenhouse gas, has more than doubled. Recent studies suggest that emission
inventories may be missing sources and underestimating emissions. To
investigate whether offshore oil and gas platforms leak CH4 during
normal operation, we measured CH4 mole fractions around eight oil and
gas production platforms in the North Sea which were neither flaring gas nor
offloading oil. We use the measurements from summer 2017, along with
meteorological data, in a Gaussian plume model to estimate CH4
emissions from each platform. We find CH4 mole fractions of between 11
and 370 ppb above background concentrations downwind of the platforms
measured, corresponding to a median CH4 emission of 6.8 g CH4 s−1 for each platform, with a range of 2.9 to 22.3 g CH4 s−1.
When matched to production records, during our measurements individual
platforms lost between 0.04 % and 1.4 % of gas produced with a median
loss of 0.23 %. When the measured platforms are considered collectively
(i.e. the sum of platforms' emission fluxes weighted by the sum of the
platforms' production), we estimate the CH4 loss to be 0.19 % of gas
production. These estimates are substantially higher than the emissions most
recently reported to the National Atmospheric Emission Inventory (NAEI) for
total CH4 loss from United Kingdom platforms in the North Sea. The NAEI
reports CH4 losses from the offshore oil and gas platforms we measured
to be 0.13 % of gas production, with most of their emissions coming from
gas flaring and offshore oil loading, neither of which was taking place at
the time of our measurements. All oil and gas platforms we observed were
found to leak CH4 during normal operation, and much of this leakage has
not been included in UK emission inventories. Further research is required
to accurately determine total CH4 leakage from all offshore oil and gas
operations and to properly include the leakage in national and international
emission inventories.
The 2015–2016 carbon cycle as seen from OCO-2 and the global in situ network
Authors: Crowell Sean , Baker David , Schuh Andrew , Basu Sourish , Jacobson Andrew R. , Chevallier Frederic , Liu Junjie , Deng Feng , Feng Liang , McKain Kathryn , Chatterjee Abhishek , Miller John B. , Stephens Britton B. , Eldering Annmarie , Crisp David , Schimel David , Nassar Ray , O'Dell Christopher W. , Oda Tomohiro , Sweeney Colm , Palmer Paul I. , Jones Dylan B. A.
Published: August 2019

Abstract. The Orbiting Carbon Observatory-2 has been on orbit since 2014, and its global coverage holds the potential to reveal new information about the carbon cycle through the use of top-down atmospheric inversion methods combined with column average CO2 retrievals. We employ a large ensemble of atmospheric inversions utilizing different transport models, data assimilation techniques, and prior flux distributions in order to quantify the satellite-informed fluxes from OCO-2 Version 7r land observations and their uncertainties at continental scales. Additionally, we use in situ measurements to provide a baseline against which to compare the satellite-constrained results. We find that within the ensemble spread, in situ observations, and satellite retrievals constrain a similar global total carbon sink of 3.7±0.5 PgC yr−1, and 1.5±0.6 PgC yr−1 for global land, for the 2015–2016 annual mean. This agreement breaks down in smaller regions, and we discuss the differences between the experiments. Of particular interest is the difference between the different assimilation constraints in the tropics, with the largest differences occurring in tropical Africa, which could be an indication of the global perturbation from the 2015–2016 El Niño. Evaluation of posterior concentrations using TCCON and aircraft observations gives some limited insight into the quality of the different assimilation constraints, but the lack of such data in the tropics inhibits our ability to make strong conclusions there.
Response of Arctic mixed-phase clouds to aerosol perturbations under different surface forcings
Authors: Eirund Gesa K. , Possner Anna , Lohmann Ulrike
Published: August 2019

Abstract. The formation and persistence of low-lying mixed-phase clouds (MPCs) in the Arctic depends on a multitude of processes, such as surface conditions, the environmental state, air mass advection, and the ambient aerosol concentration.
In this study, we focus on the relative importance of different instantaneous aerosol perturbations (cloud condensation nuclei and ice-nucleating particles; CCN and INPs, respectively) on MPC properties in the European Arctic. To address this topic, we performed high-resolution large-eddy simulation (LES) experiments using the Consortium for Small-scale Modeling (COSMO) model and designed a case study for the Aerosol-Cloud Coupling and Climate Interactions in the Arctic (ACCACIA) campaign in March 2013. Motivated by ongoing sea ice retreat, we performed all sensitivity studies over open ocean and sea ice to investigate the effect of changing surface conditions.
We find that surface conditions highly impact cloud dynamics, consistent with the ACCACIA observations: over sea ice, a rather homogeneous, optically thin, mixed-phase stratus cloud forms. In contrast, the MPC over the open ocean has a stratocumulus-like cloud structure. With cumuli feeding moisture into the stratus layer, the cloud over the open ocean features a higher liquid (LWP) and ice water path (IWP) and has a lifted cloud base and cloud top compared to the cloud over sea ice.
Furthermore, we analyzed the aerosol impact on the sea ice and open ocean cloud regime. Perturbation aerosol concentrations relevant for CCN activation were increased to a range between 100 and 1000 cm−3 and ice-nucleating particle perturbations were increased by 100 % and 300 % compared to the background concentration (at every grid point and at all levels). The perturbations are prognostic to allow for fully interactive aerosol–cloud interactions.
Perturbations in the INP concentration increase IWP and decrease LWP consistently in both regimes. The cloud microphysical response to potential CCN perturbations occurs faster in the stratocumulus regime over the ocean, where the increased moisture flux favors rapid cloud droplet formation and growth, leading to an increase in LWP following the aerosol injection. In addition, IWP increases through new ice crystal formation by increased immersion freezing, cloud top rise, and subsequent growth by deposition. Over sea ice, the maximum response in LWP and IWP is delayed and weakened compared to the response over the open ocean surface. Additionally, we find the long-term response to aerosol perturbations to be highly dependent on the cloud regime. Over the open ocean, LWP perturbations are efficiently buffered after 18 h simulation time. Increased ice and precipitation formation relax the LWP back to its unperturbed range. On the contrary, over sea ice the cloud evolution remains substantially perturbed with CCN perturbations ranging from 200 to 1000 CCN cm−3.
Past climate and continentality inferred from ice wedges at Batagay megaslump in the Northern Hemisphere's most continental region, Yana Highlands, interior Yakutia
Authors: Opel Thomas , Murton Julian B. , Wetterich Sebastian , Meyer Hanno , Ashastina Kseniia , Günther Frank , Grotheer Hendrik , Mollenhauer Gesine , Danilov Petr P. , Boeskorov Vasily , Savvinov Grigoriy N. , Schirrmeister Lutz
Published: August 2019

Abstract. Ice wedges in the Yana Highlands of interior Yakutia – the most continental
region of the Northern Hemisphere – were investigated to elucidate changes
in winter climate and continentality that have taken place since the Middle Pleistocene. The
Batagay megaslump exposes ice wedges and composite wedges that were sampled
from three cryostratigraphic units: the lower ice complex of likely
pre-Marine Isotope Stage (MIS) 6 age, the upper ice complex (Yedoma) and the
upper sand unit (both MIS 3 to 2). A terrace of the nearby Adycha River
provides a Late Holocene (MIS 1) ice wedge that serves as a modern reference
for interpretation. The stable-isotope composition of ice wedges in the MIS 3 upper ice complex at Batagay is more depleted (mean δ18O
about −35 ‰) than those from 17 other ice-wedge study
sites across coastal and central Yakutia. This observation points to lower
winter temperatures and therefore higher continentality in the Yana
Highlands during MIS 3. Likewise, more depleted isotope values are found in
Holocene wedge ice (mean δ18O about −29 ‰)
compared to other sites in Yakutia. Ice-wedge isotopic signatures of the
lower ice complex (mean δ18O about −33 ‰)
and of the MIS 3–2 upper sand unit (mean δ18O from about −33 ‰ to
−30 ‰) are less distinctive regionally. The latter unit
preserves traces of fast formation in rapidly accumulating sand sheets and
of post-depositional isotopic fractionation.
Enabling a new method of dynamic field-effect gas sensor operation through lithium-doped tungsten oxide
Authors: Rodner Marius , Bastuck Manuel , Schütze Andreas , Andersson Mike , Huotari Joni , Puustinen Jarkko , Lappalainen Jyrki , Sauerwald Tilman
Published: August 2019

Abstract. To fulfil today's requirements, gas sensors have to become more and more sensitive and selective. Temperature-cycled operation has long been used to enhance the sensitivity and selectivity of metal-oxide semiconductor gas sensors and, more recently, silicon-carbide-based, gas-sensitive field-effect transistors (SiC-FETs). In this work, we present a novel method to significantly enhance the effect of gate bias on a SiC-FET's response, giving rise to new possibilities for static and transient signal generation and, thus, increased sensitivity and selectivity. A tungsten trioxide (WO3) layer is deposited via pulsed laser deposition as an oxide layer beneath a porous iridium gate, and is doped with 0.1 AT % of lithium cations. Tests with ammonia as a well-characterized model gas show a relaxation effect with a time constant between 20 and 30 s after a gate bias step as well as significantly increased response and sensitivity at +2 V compared to 0 V. We propose an electric field-mediated change in oxygen surface coverage as the cause of this novel effect.
Analysis of properties of the 19 February 2018 volcanic eruption of
Mount Sinabung in S5P/TROPOMI and Himawari satellite data
Authors: de Laat Adrianus , Vazquez-Navarro Margarita , Theys Nicolas , Stammes Piet
Published: August 2019

Abstract. This study presents an analysis of TROPOMI cloud heights as a proxy for volcanic plume heights in the presence of absorbing aerosols and sulfur dioxide for the 19 February 2018 eruption plume of the Sinabung volcano on Sumatra, Indonesia. Comparison with CALIPSO satellite data shows that all three TROPOMI cloud height data products based on oxygen absorption which are considered here (FRESCO, ROCINN, O22CLD) provide volcanic ash heights comparable to heights measured by CALIPSO for optically thick volcanic ash clouds. FRESCO and ROCINN heights are very similar with only differences for FRESCO cloud top heights above 14 km altitude. O22CLD cloud top heights unsurprisingly fall below those of FRESCO and ROCINN, as the O22CLD retrieval is less sensitive to cloud top heights above 10 km altitude. For optically thin volcanic ash clouds, i.e. when Earth’s surface or clouds at lower altitudes shine through the volcanic ash cloud, retrieved heights fall below the volcanic ash heights derived from CALIPSO data. Evaluation of corresponding Himawari geostationary volcanic ash height retrievals based on InfraRed (IR) brightness temperature differences (ΔBT) reveals that for this particular eruption the ΔBT volcanic ash signature – widely used for detection of volcanic ash in geostationary satellite data – changes to a ΔBT ice crystal signature for the part of the ash plume reaching the upper troposphere beyond 10 km altitude several hours after the start of the eruption and which TROPOMI clearly characterizes as volcanic (SO2 > 1 DU and AAI > 4 or more conservatively SO2 > 10). The presence of ice in volcanic ash clouds is known to prevent the detection of volcanic ash based on broadband geostationary satellite data. TROPOMI does not suffer from this effect, and can provide valuable and accurate information about volcanic ash clouds and ash top heights in cases where commonly used geostationary IR measurements of volcanic ash fail.
Antibiotic Resistance of Azotobacter Isolated from Mercury-Contaminated Area
Authors: Hindersah Reginawanti , Nurhabibah Gina , Asmiran Priyanka , Pratiwi Etty
Published: August 2019

Nitrogen-fixing Azotobacter is a renewable source of biofertilizer for plant growth. Increased of antibiotic level in soil due to intensive used manure is believed to induce bacterial sensitivity to antaibiotic. An antibiotic sensitivity test has been carried out to study the inhibition effect of ampicillin, streptomycin, tetracycline and chloramphenicol on Azotobacter isolated from mercury-contaminated taling. The resistance test was performend by using disc plate method in Nitrogen-free Ashby’s agar with and without mercury. The results showed that the presence of 20 mg/L mercury in plate agar totally inhibited Azotobater growth. In the absence of mercury chloride, all isolates showed different sensitivity to antibiotics. Growth of Azotobacter buru1 was only inhibited by tetracycline. Azotobacter buru2 was susceptible to high and low concentration of tetracycline and streptomycin but they were resistance to low concentration of chloramphenicol as well as ampicillin; while Azotobacter bd3a were sensitive to all tested antibiotic. In conclusion, order of Azotobacter resistance to antibiotics in the absence of mercury was Bd3a<Buru2<Buru1. This research have not revealed the resistance of Azotobacter to antibiotic in the presence of mercury.
Nutritive Values of the Leaves of Crescentia Cujete (Ugbuba)
Authors: Queen Umudi E.
Published: August 2019

Mineral and proximate analysis of Crescentia Cujete (Ugbugba) leaves were examined using the methods recommended by Association of Official Analytical Chemist (AOAC). The leaves contained 51.00+1.05% moisture, 2.30+0.2% ash, crude protein 51.00+0.43%, crude lipid 1.90+0.08%, crude fibre 4.00+0.12%, carbohydrates 40.40+0.02%. The minerals ranges from mg/g dry weight K(30.02 + 0.03), Na (12.10+0.32), Ca (60.00+0.01). Mg (361.42+0.01), P(14.19 +0.42), Mn (6.32 + 1.01), Fe (2.43+0.01), Cu (13.04+0.10), Zn (1.20+0.43), Na/K (0.40) and Ca/P (2.14), K, Mg, Ca and Fe were found in significant concentrations. The findings showed that Crescentia Cujete leaves are source of nutrients for edible purpose, a good Na/K ratio for lowering blood pressure.