bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface adhesion of phototrophic biofilms
Authors: Stiefelmaier Judith , Strieth Dorina , Schaefer Susanne , Kronenberger Daniel , Wrabl Björn , Bröckel Ulrich , Ulber Roland
Published: July 2020

Cyanobacteria belong to the oldest known microorganisms and are capable of oxygenic photosynthesis. Depending on their habitat aquatic and terrestrial cyanobacteria are distinguished. Terrestrial cyanobacteria grow embedded in a matrix of extracellular polymeric substances (EPS) as phototrophic biofilms. Those EPS serve as nutrient storage, protection from desiccation and play an important role in surface adhesion. For cultivation of phototrophic biofilms different biofilm reactors have been developed in the last years. One interesting parameter when cultivating biofilms is the surface material and structure, since it can influence the surface adhesion and thus biofilm formation. Therefore, different materials as cultivation surfaces were investigated as well as the strain specific behavior of different cyanobacteria and the impact on EPS formation. In this work the adhesion of the terrestrial cyanobacteria Coleofasciculus chthonoplastes and Trichocoleus sociatus to different materials was investigated. For characterization of materials measurements concerning surface roughness were conducted using atomic force microscopy. Biofilms were cultivated in an aerosol and the development of surface adhesion in connection with biofilm age was analyzed using two different methods. In the first set-up biofilms were placed in a specially designed flow-through chamber and overflown with medium at increasing flow speed. The detachment of the biofilm was documented with optical coherence tomography (OCT). Additionally, the experiments were supplemented with CFD-simulation for quantification of shear forces. The second method analyzed adhesion forces using rotational rheometry. Hereby, differences between cyanobacteria strains and surface materials could be observed as well as an increasing adhesion with increasing cultivation time. The developed flow-through chamber, which could as well be utilized with a camera instead of OCT, offers a simple low-priced possibility for investigation of surface adhesion.

This project is financially supported by the German Research Foundation (DFG; Project number: UL 170/16-1; MU 2985/3-1 and SFB 926) and the Landesförderung Rheinland-Pfalz (Project: iProcess).
Peptides’ involvement in Pseudomonas putida biofilm formation
Authors: Teras Riho , Ainelo Hanna , Puhm Marge
Published: July 2020

Pseudomonas putida rapidly forms a biofilm, after which its biomass usually disperses to half its initial amount. We have observed different biofilm dynamics of P. putida in a complex medium LB and a minimal medium M9+glc+CAA and inquired about the importance of extracellular factors for the formation of P. putida biofilm.

The proteinaceous component of LB increases the biomass of P. putida biofilm. Supplementation of M9 with tryptone but not CAA increased the biofilm biomass. Proteinase K treatment of LB medium reduced the biomass of P. putida biofilm. At the same time, growth rate or maximum OD of planktic bacteria in used media did not correlate with biofilm biomass of the same media. Thus, peptides appeared to have a positive effect on the biofilm as an extracellular factor and not as a source of C and N.

We replaced tryptone in M9 medium with positively charged poly-L-lysine (MW. 1000-5000 Da), negatively charged poly-L-glutaminic acid (MW. 1500-5500 Da) or neutral poly-LD-alanine (MW. 3000-7000). Poly-lysine and poly-glutamic acid had a slight positive effect on the biomass of P. putida wild type strain PSm biofilm and poly-alanine did not affect the biofilm.

We have previously shown that overexpression of fis in P. putida strain F15 increases biofilm biomass by increasing the lapA expression, the main adhesin gene of biofilm. Using media similar to that used for the wild-type strain for strain F15, we ascertained that only poly-lysine out of these three polypeptides restored the positive effect of fis-overexpression on the biofilm biomass. At the same time, the positive impact of fis-overexpression was absent in lapA deletion mutant strain, but not in lapF deletion mutant strain.

In conclusion, the formation of P. putida biofilm depends on polypeptides in the environment. The enhancing effect of positively charged polypeptides appears to be evident in the presence of LapA, a key factor for P. putida biofilm.
Staphylococcus aureus biofilm matrix under bone environment influence
Authors: Lamret Fabien , Varin-Simon Jennifer , Gangloff Sophie , Reffuveille Fany
Published: July 2020

Bone and joint infections linked to implanted materials are mostly due to Staphylococcus aureus. Deciphering the biofilm structure appears to be a promising strategy to develop antibiofilm molecules in order to curb infection occurrence and the bacterial recurrence. Indeed, the characterization of biofilm architecture and physiology could help to find new therapeutic targets through notable quantification of the matrix main components. Our hypothesis is that the very complex and interconnected bone microenvironment influences the bacterial adhesion and biofilm maturation and so its composition.

To identify the main factors influencing biofilm formation in the bone microenvironment, we determined biofilm biomass and the number of live adhered bacteria in a static model, completed with microscopy approaches to support our results. Different factors of bone microenvironment were tested: starvation, low oxygen rate, excess of magnesium, and presence of bone cell products. Our first results showed that MSSA or MRSA strains did not have the same behaviors under the tested conditions. However, for both types of strains, excess of magnesium combined to paucity of amino acids and oxygen increased the most the proportion of adhered Staphylococcus aureus (a 6 to 43 fold-increase, p = < 0.01). But biofilm biomass quantification and bacterial adhesion results showed divergent profiles leading us to think that matrix could be involved in such contrasts. Scanning electron microscopy highlighted several structures of matrix produced by these bacteria: well-known slime aspect, but also fibrous appearance, and no matrix production was revealed under some conditions. Indeed, all strains produced few matrix when cultured with control medium and oxygenated condition. Only CIP 53.154 strain built a strong slime-like matrix in response to oxygen depletion. However, both MSSA CIP 53.154 and SH1000 strains developed fibrous structures under anaerobic conditions associated with amino acid starvation, high magnesium concentration with or without glucose. MRSA USA300 strain did not seem to produce a matrix under our conditions, which is supported by the literature. Further investigations of the biofilm matrix are needed to conclude on the matrix nature, which surrounds bacteria under our conditions.

The bone microenvironment is complex but our results show that the parameters that mimicked this specific environment influenced the bacterial adhesion and probably the biofilm matrix composition of several strains of Staphylococcus aureus. Further investigations will help to understand how the different factors influence biofilm formation through quantification of the matrix main components by fluorescence microscopy and enzyme digestion. Our final aim is to develop an in vitro model mimicking this specific microenvironment in order to screen different antimicrobial molecules, which could target the biofilm matrix.
Archaeal biofilms: Composition of extracellular polymeric substances, exopolysaccharide synthesis and secretion in Sulfolobus acidocaldarius
Authors: Kuschmierz Laura , Meyer Martin , Meyer Benjamin , Albers Sonja-Verena , Bräsen Christopher , Wingender Jost , Schmitz Oliver J. , Siebers Bettina
Published: July 2020

Archaea, representatives of the third domain of life, are often referred to as “extremophiles” since most of the cultivable species are adapted to extreme environments [1]. However, environmental cultivation-independent approaches (metagenomics) revealed a wide distribution of Archaea in moderate habitats suggesting a major role in geochemical processes. Similar to Bacteria, also Archaea are believed to exist predominantly in the biofilm mode, but knowledge about archaeal biofilm formation and structure, extracellular polymeric substance (EPS) composition and synthesis is scarce [2].

Sulfolobus acidocaldarius is a thermoacidophilic, aerobic Crenarchaeon (78°C and pH 2-3) that was isolated from acid hot springs [3]. The organism is easy to cultivate under laboratory conditions and a genetic system is established. In this study, we investigate S. acidocaldarius biofilms with a special focus on synthesis and transport of exopolysaccharides (PS). PS constitute a major EPS component beside proteins and eDNA, suggesting an important role in Sulfolobus biofilms, and changes in PS composition were observed in response to environmental stress [4]. A gene cluster encoding several glycosyltransferases (GTs) as well as membrane proteins (MPs), likely involved in exopolysaccharide synthesis, was identified in S. acidocaldarius. Several deletion mutants have been constructed lacking certain GT and MP encoding genes from the PS gene cluster. A combination of methods including the quantification of biofilm formation, isolation and quantification of EPS components, visualization of biofilm and PS structures via confocal laser scanning microscopy as well as molecular and biochemical techniques have been applied to compare biofilm characteristics of wildtype and mutant strains. First insight into the function of GTs and MPs will be presented and a model of PS synthesis and export will be proposed.

[1] Schocke et al. (2019). Curr. Opin. in Biotechnol. 59, 71-77.

[2] van Wolferen et al. (2018). Nature Rev. Microbiol. 16(11), 699-713.

[3] Brock et al. (1972). Arch. Mikrobiol. 84, 54-68.

[4] Jachlewski et al. (2015). Front. Bioeng. Biotechnol. 3, 123.

 
Iron as a biofilm control agent: manipulation of biofilm development and differentiation
Authors: Gierl Luisa , Horn Harald , Wagner Michael
Published: July 2020

In order to optimize operative parameters in wastewater treatment plants, drip irrigation systems as well as in biofilm reactors, it is necessary to understand biofilm development and proliferation under certain conditions. Additionally, the physical structure of biofilms is of great interest since it determines the interaction with its microenvironment, while knowledge about the mechanical behavior of biofilms is important for applying e.g., cleaning procedures.

In the past two years we refined a fully automated monitoring and cultivation setup that enabled replicate biofilm cultivations and investigation by means of optical coherence tomography (OCT). OCT as an imaging modality is ideal for biofilms since it allows for the monitoring of structure and deformation in real-time and noninvasively.

With this setup it was possible to analyze the effect of iron on biofilm growth and behavior with a minimum of N = 10 biofilm replicates including a statistical treatment. At least eight structural parameters of biofilms grown in flow cells could be analyzed and statistically quantified, providing insights into the structural integrity of biofilms and to their interface. Thereby, the results clearly show the positive effect of iron on Bacillus subtilis biofilms regarding biomass production and differentiation to mature biofilms. Further gravimetric and optical analyses prove the incorporation of iron as iron oxide-hydroxides and explain the positive effect on the biofilm’s matrix. Initial experiments under mechanical stress confirm the withstanding of high flow rates as well as a high compressibility of the biofilms.
Mixed-trophies two species biofilms driven by Cyanobacteria for biotechnnological applications
Authors: Bühler Katja , Hoschek Anna , Schmid Andreas , Heuschkel Ingeborg , Karande Rohan
Published: July 2020

 

Despite photo-biocatalysis developing remarkably and the huge potential of photoautotrophic microorganisms for eco-efficient production scenarios, photo-biotechnology is still in its infancy. The lack of scalable photo-bioreactors that provide efficient light transmission, CO2 supply, and O2 degassing and thus enable high cell densities (HCD), constitutes a key bottleneck, especially if cost-sensitive bulk chemicals are the product of choice. Commercialized tubular photo-bioreactors with 100 to 600 mm inner diameter offer a surface area to volume ratio (SA/V) of over 100 m2 m-3 enabling the efficient capturing of incident solar radiation.1 Here we introduce a new generation of photo-bioreactors based on capillary biofilm reactors. The biofilm is composed of two strains, namely the photoautotrophic strain Synechocystis sp. PCC 6803 and the chemoheterotrophic strain Pseudomonas taiwanensis VLB120, which serves as a biofilm supporter strain. Pseudomonas sp. is lowering the pO2 in the system, which otherwise would toxify the Cyanobacteria. Furthermore, it produces extrapolymeric substances (EPS) and produces a kind of seeding layer promoting the attachment of Synechocystis sp.. Synechocystis sp. on the other hand produces organic compounds and oxygen consumed by Pseudomonas sp. The system is run completely without any organic carbon source.

Depending on the functionalities engineered into the biofilm forming organisms, these systems can be used for biotechnological applications. Here, we will present data on the physiology of the mixed trophies biofilm, and the challenging conversion of cyclohexane to caprolactone, and further on to 6-hydroxyadipic acid, both being important monomers for Nylon production.

 

References

[1] Posten, C. Eng. In Life Science. (2009) 9:165-177

[2] Hoschek, A. et al Bioresource Technology. (2019) 282: 171-178

 

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Assessing arsenic bioremediation potential of epilithic biofilms affected by acid-mine drainage
Authors: Zecchin Sarah , Guerrieri Nicoletta , Jongepier Evelien , Scaglioni Leonardo , Borgonovo Gigliola , Muyzer Gerard , Cavalca Lucia
Published: July 2020

Arsenic is a toxic but naturally abundant metalloid that globally leads to contamination in groundwater and soil, exposing millions of people to cancer and other arsenic-related diseases. In several areas in Northern Italy arsenic in soil and water exceeds law limits (20 mg kg-1 and 10 mg L-1, respectively), due to both the mineralogy of bedrock and former mining activities. The Rio Rosso stream, located in the Anzasca Valley (Piedmont) is heavily affected by an acid mine drainage originated from an abandoned gold mine. Arsenic, together with other heavy metals, is transferred by the stream to the surrounding area. The stream is characterized by the presence of an extensive reddish epilithic biofilm at the opening of the mine and on the whole contaminated waterbed.

The aim of this study was to characterize the mechanisms allowing the biotic fraction of this biofilm to cope with extreme arsenic concentrations. The composition and functionality of the microbial communities constituting the epilithic biofilms sampled in the close proximity and downstream the mine were unraveled by 16S rRNA genes and shotgun Illumina sequencing in relation to the extreme physico-chemical parameters. In parallel, autotrophic and heterotrophic microbial populations were characterized in vivo by enrichment cultivation and isolated strains were tested for their ability to perform arsenic redox transformation.

Preliminary analyses indicated that the biofilm accumulated arsenic in the order of 6 · 103 mg kg-1, in contrast to 0.14 mg L-1, measured in the surrounding water. The main chemical parameter affecting the composition of the microbial community was the pH, being 2 next to the mine and 6.7 in the downstream sampling point. In both sampling sites iron- and sulfur-cycling microorganisms were retrieved by both cultivation and molecular methods. However, the diversity of the microbial community living next to the mine was significantly lower with respect to the community developed downstream. In the latter, autotrophic Cyanobacteria belonging to the species Tychonema were the dominant taxa. A complete arsenic cycle was shown to occur, with heterotrophic bacteria mainly responsible for arsenate reduction and autotrophic bacteria performing arsenite  oxidation.

These observations indicate that the epilithic biofilm living in the Rio Rosso stream represents a peculiar ecosystem where microorganisms cope with metalloid toxicity likely using diverse mechanisms. Such microbial metabolic properties might be exploited in bioremediation strategies applied in arsenic-contaminated environments.
Surface Functionalization-Dependent Physicochemical Interactions between Nanoparticles and the Biofilm EPS Matrix
Authors: Hiebner Dishon , Barros Caio , Quinn Laura , Vitale Stefania , Casey Eoin
Published: July 2020

The contribution of the biofilm extracellular polymeric substance (EPS) matrix to reduced antimicrobial susceptibility in biofilms is widely recognised.  As such, directly targeting the EPS matrix is a promising biofilm control strategy that allows for efficient disruption of the matrix to allow an increase in susceptibility to antibiofilm agents. To this end, engineered nanoparticles (NPs) have received considerable attention. However, the fundamental understanding of the physicochemical interactions occurring between NPs and the EPS matrix has not yet been fully elucidated. An insight into the underlying mechanisms involved when a NP interacts with molecules in the EPS matrix will aid in the design of more efficient systems for biofilm control. The use of highly specific fluorescent probes in confocal laser scanning microscopy (CLSM) to illustrate the spatial distribution of EPS macromolecules within the biofilm is demonstrated. Three-dimensional (3D) colocalization analysis was used to assess the affinity of differently functionalized silica NPs (SiNPs) for specific EPS macromolecules from Pseudomonas fluorescens biofilms. Results show that both the charge and surface functional groups of SiNPs dramatically affect the extent to which SiNPs interact and localize with EPS macromolecules, including proteins, polysaccharides, and DNA. This research not only develops an innovative strategy for biofilm-nanoparticle interaction studies but also provides a platform on which to build more efficient NP systems for biofilm control.
Real-time reservoir flood control operation enhanced by data assimilation
Authors: Zhang Jingwen , Cai Ximing , Lei Xiaohui , Liu Pan , Wang Hao
Published: July 2020

Abstract. Real world reservoir operations are usually not fully automatic based on computer models; instead, reservoir operators conduct the operations based on their experiences, professional justification, as well as modeling support for some cases due to unavoidable gap between computer modeling and real world reservoir operation conditions. In this paper, we propose a human-machine interactive method, namely Real-time Optimization Model Enhanced by Data Assimilation (ROMEDA) for reservoirs which have complex storage and stage relations (e.g. long and narrow reservoirs). The system is composed of 1) an optimization model to search for optimal releases, 2) reservoir operators’ choices based on their experiences, knowledge, and behaviors, and 3) a reservoir storage-stage simulation and data assimilation schedule to update the storage based on real-time reservoir stage observations. For every time period and based on the updated storage, ROMEDA provides optimal releases as recommendations, actual releases made by operators, as well as a warning of flood risk when the storage exceeds a threshold level. ROMEDA does not assume that operators strictly accept the recommendations, and storage will be updated based on actual release at each time period. Via a case study on-channel reservoir, it is found that for both small and large flood events, ROMEDA, which integrates the advantages of both machine and human, shows better performance on flood risk mitigation and water use (hydropower) benefit than the case with historical operation records (HOR) or optimization with single/multi-objective. ROMEDA is one of the first attempts of a human-machine interactive method for online use of an optimization model for real-time reservoir operation based on integrated modeling, observation, and operators’ choice.
Anomalous distribution of distinctive water masses over the Carlsberg Ridge in May 2012
Authors: He Hailun , Wang Yuan , Han Xiqiu , Wei Yanzhou , Lin Pengfei , Qiu Zhongyan , Wang Yejian
Published: July 2020

Abstract. In May 2012, we conducted a hydrographic survey over the Carlsberg Ridge in the northwest Indian Ocean.
In this paper, we use these station data, in combination with some free-floating Argo profiles, to obtain the sectional temperature and salinity fields, and subsequently, the hydrographic characteristics are comprehensively analyzed.
Through the basic T–S diagram, three salty water masses, Arabian Sea High-Salinity Water, Persian Gulf Water, and Red Sea Water, are identified.
The sectional data show a clear ventilation structure associated with Arabian Sea High-Salinity Water. The 35.8 psu salty water sinks at 6.9∘ N and extends southward to 4.4∘ N at depths around the thermocline, where the thermocline depth is in the range of 100 to 150 m.
This salty thermocline extends much further south than climatology indicates.
Furthermore, the temperature and salinity data are used to compute the absolute geostrophic current over the specific section, and the results show mesoscale eddy vertical structure different from some widely used oceanic reanalysis data.
We also find a west-propagating planetary wave at 6∘ N, and the related features are described in terms of phase speed and horizontal and vertical structures.
Statistical predictability of the Arctic sea ice volume anomaly: identifying predictors and optimal sampling locations
Authors: Ponsoni Leandro , Massonnet François , Docquier David , Van Achter Guillian , Fichefet Thierry
Published: July 2020

Abstract. This work evaluates the statistical predictability of the Arctic sea ice volume (SIV) anomaly –
here defined as the detrended and deseasonalized SIV – on the interannual timescale.
To do so, we made use of six datasets, from three different atmosphere–ocean general circulation models,
with two different horizontal grid resolutions each. Based on these datasets, we have developed a statistical
empirical model which in turn was used to test the performance of different predictor variables, as well as to
identify optimal locations from where the SIV anomaly could be better reconstructed and/or predicted. We tested
the hypothesis that an ideal sampling strategy characterized by only a few optimal sampling locations can provide
in situ data for statistically reproducing and/or predicting the SIV interannual variability. The results
showed that, apart from the SIV itself, the sea ice thickness is the best predictor variable, although total sea
ice area, sea ice concentration, sea surface temperature, and sea ice drift can also contribute to improving the
prediction skill. The prediction skill can be enhanced further by combining several predictors into the statistical
model. Applying the statistical model with predictor data from four well-placed locations is sufficient for
reconstructing about 70 % of the SIV anomaly variance.
As suggested by the results, the four first best locations are placed at the transition Chukchi Sea–central Arctic–Beaufort Sea (79.5∘ N, 158.0∘ W), near the North Pole (88.5∘ N, 40.0∘ E), at the transition central Arctic–Laptev Sea (81.5∘ N, 107.0∘ E), and offshore the Canadian Archipelago (82.5∘ N, 109.0∘ W), in this respective order. Adding further to six well-placed locations, which explain about 80 % of the SIV anomaly variance, the statistical
predictability does not substantially improve taking into account that 10 locations explain about 84 % of that variance.
An improved model horizontal resolution allows a better trained statistical model so that the reconstructed
values better approach the original SIV anomaly. On the other hand, if we inspect the interannual variability, the
predictors provided by numerical models with lower horizontal resolution perform better when reconstructing the original
SIV variability.
We believe that this study provides recommendations for the ongoing and upcoming observational initiatives, in terms of an Arctic optimal
observing design, for studying and predicting not only the SIV values but also its interannual variability.
Ice loss in High Mountain Asia and the Gulf of Alaska observed by
CryoSat-2 swath altimetry between 2010 and 2019
Authors: Jakob Livia , Gourmelen Noel , Ewart Martin , Plummer Stephen
Published: July 2020

Abstract. Glaciers and ice caps are currently the largest non-steric contributor to sea level rise, contributing ~30 % to sea level budget. Global monitoring of these regions remains a challenging task since global estimates rely on a variety of observations and models to achieve the required spatial and temporal coverage, and significant differences remain between current estimates. Here we report the first application of a novel approach to retrieve spatially-resolved elevation and mass change from Radar Altimetry over entire mountain glaciers areas. We apply interferometric swath altimetry to CryoSat-2 data acquired between 2010 and 2019 over High Mountain Asia (HMA) and in the Gulf of Alaska (GoA). In addition, we extract monthly time series of elevation change, exploiting CryoSat's high temporal repeat, to reveal seasonal and multiannual variation in rates of glaciers' thinning at unprecedented spatial detail. We find that during this period, HMA and GoA have lost an average of −27.9 ± 2.4 Gt yr−1 (−0.29 ± 0.03 m w.e. yr−1) and −76.3 ± 5.6 Gt yr−1 (−0.89 ± 0.07 m w.e. yr−1) respectively, corresponding to a contribution to sea level rise of 0.048 ± 0.004 mm yr−1 and 0.217 ± 0.015 mm yr−1. Glacier thinning is ubiquitous except for the Karakoram-Kunlun region experiencing stable or slightly positive mass balance. In the GoA region the intensity of thinning varies spatially and temporally and correlates with the strength of the Pacific Decadal Oscillation. In HMA we observe sustained multiannual trends until 2015-6, and decreased loss or even mass gain from 2016-17 onwards.
The role of Arctic sea ice loss in projected polar vortex changes
Authors: Kretschmer Marlene , Zappa Giuseppe , Shepherd Theodore G.
Published: July 2020

Abstract. The Northern Hemisphere stratospheric polar vortex (SPV) plays a key role for mid-latitude weather and climate. However, in what way the SPV will respond to global warming is not clear, with climate models disagreeing on the sign and magnitude of projected SPV strength change. Here we address the role of Barents and Kara (BK) sea ice loss in this. We provide evidence for a non-linear response of the SPV to global mean temperature change, dependent on the time the BK Seas become ice-free. Using a causal network approach, we demonstrate that climate models show some partial support for the previously proposed link between low BK sea ice in autumn and a weakened winter SPV, but that this effect is plausibly very small relative to internal variability. Yet, given the expected dramatic decrease of sea ice in the future, a small causal effect can explain all of the projected ensemble-mean SPV weakening, approximately one-half of the ensemble spread at the middle of the 21st century, and one-third of the spread at the end of the century. Finally, we note that most models have unrealistic amounts of BK sea ice, meaning that their SPV response to ice loss is unrealistic. Bias-adjusting for this effect leads to pronounced differences in SPV response of individual models at both ends of the spectrum, but has no strong consequences for the overall ensemble mean and spread. Overall, our results indicate the importance of exploring all plausible implications of a changing Arctic for regional climate risk assessments.
Leadership Styles and Organisational Structure
Authors: Steyn Renier
Published: July 2020

Background: In the call for papers to the 18th International Studying Leadership Conference, the organisers present an argument that leadership is place-bound, and ask a very specific question: “Why does leadership style vary from place-to-place?” This article presents a response to the assumption implicit in this question and also answers the following question: “Does leadership style differ from place-to-place?” Theoretical underpinning: The link between leadership styles and organisational structure is implicit, given general systems theory (Von Bertalanffy, 1968). Leadership styles are presented in terms of Pearce, Sims Jr, Cox, Ball, Schnell, Smith and Treviño’s (2003) typology of leadership styles and organisational structure typology, as specified by Mintzberg’s (1992, 2009). Aim: The aim of this article is to present empirical information on the relationship between leadership styles and the organisational structures within which they manifest. This will provide an answer to the question, “Does leadership style differ from place-to-place?” Ultimately, this may contribute to aligning leaders to organisations. Setting: Data was collected from nine medium-to-large sized organisations operating within an urban environment in South Africa. Method: A cross-sectional survey design was used to collect quantitative data on leadership styles. Data on organisational structure was collected by subject matter experts. Analyses of variance were performed to test hypotheses that leadership styles are equal across organisational structures. Results: The measures of leadership styles showed acceptable levels of reliability and evidence of factorial validity. Statistically significant differences between the leadership styles were detected for transformational, transactional, and directive leadership, but not for empowering leadership. Only for directive leadership were these differences practically significant. These results were linked to organisational structure data. Discussion: Although it is not difficult to create hypotheses linking leadership styles with organisational structure, it was difficult to find these differences in the data and to find cases where these hypotheses held across all the organisations. Practical significant differences occurred for directive leadership only. Conclusion: Before asking, “Why does leadership style vary from place-to-place?” this research asked, “Does leadership style differ from place-to-place?” Given this particular sample, and the manner in which place was defined, place does not seem to dictate the leadership style present in a particular environment.
Analysis of the Sociolinguistic Status of Saudi Female Personal Names
Authors: Alzamil Aseel I
Published: July 2020

Names are more likely to be considered as cultural tags used to signify some deep-rooted aspects within the culture of a given speech community. In Saudi Arabia, naming is linked with religion, traditions, values, beliefs, and events in people's lives. This paper aims at investigating Saudi female personal names from a sociolinguistic perspective and it suggests that these names are not mere arbitrary tags, but socio-cultural labels that occupy socio-cultural meanings and functions. For this reason, the current study draws on a stratified sample size of 280 Saudi female personal names collected by the researcher qualitatively by means of oral interviews as the tool for data collection. The analysis takes the form of a typology of Saudi female personal names and they were classified into different categories such as names relating to religious backgrounds, Bedouin-bound names, kinship names, family names, circumstantial names, foreign names, etc. As a result, the study will be a valuable contribution to the body of Arabic anthroponomy as it shows how the selection of Saudi female personal names is influenced by the ideology, culture, religion, attitudes, and social values of Saudi communities. The study concludes that that (delete) the spread of foreign names may constitute a threat to the cultural identity of Saudis, an argument that calls for further investigation to either confirm or disconfirm it.
Menselijke waardigheid en een waardige levensstandaard; de uitspraak van het Hof van Justitie inzake Zubair Haqbin
Authors: Terlouw A.B. , Zwaan K.M.
Published: July 2020

Menselijke waardigheid en een waardige levensstandaard; de uitspraak van het Hof van Justitie inzake Zubair Haqbin

Richtlijn 2013/33/EU (de Opvangrichtlijn) regelt welke opvangvoorzieningen aan asielzoekers moeten worden verstrekt en ook hun rechten op documenten, onderwijs en toegang tot de arbeidsmarkt en gezondheidszorg. In de uitspraak HvJ 12 november 2019, zaak C-233/18 inzake Zubair Haqbin oordeelt het Hof van Justitie dat de intrekking – al was het maar tijdelijk – van alle materiële opvangvoorzieningen of van de materiële opvangvoorzieningen die betrekking hebben op huisvesting, voeding of kleding, onverenigbaar is met de verplichting om ervoor te zorgen dat Haqbin een waardige levensstandaard geniet. Een dergelijke sanctie ontneemt hem immers de mogelijkheid om te voorzien in zijn meest elementaire behoeften.

HvJ 12 november 2019, zaak C-233/18, ECLI:EU:C:2019:956 (Zubair Haqbin/Federaal Agentschap voor de opvang van asielzoekers, België)
Pleomorphic adenoma of the nasal cavity
– a case report
Authors: Frączek Anna , Szczygielska Julia , Majszyk Daniel , Niemczyk Kazimierz
Published: July 2020

Introduction: Pleomorphic adenoma is a benign tumor which occurs most commonly in the major salivary glands. It is very rare in the nasal cavity and may be misdiagnosed because of its uncharacteristic clinical and histopathological manifestation.
Case report: A case of a 42-year-old patient with pleomorphic adenoma on the lateral nasal wall has been presented. The tumor was accidentally found during FESS and septorhinoplasty. Initially, based on the histopathological examination of the obtained sample, there was a suspicion of adenoid cystic carcinoma. Later, the neoplasm was completely removed by the open septorhinoplasty and histopathological re-examination showed features of pleomorphic adenoma. Long term followup was necessary due to the potential risk of local recurrence.
ESTIMATES OF SUBSISTENCE MINIMUM BASKETS AND SOCIAL MINIMUM BASKETS FOR 2019
Authors: Kurowski Piotr
Published: July 2020

The article presents estimates of Subsistence minimum as well as Social minimum baskets based on average prices of 2019. Both indicators are important for assessing the well-being of households. Subsistence minimum defines the lowest possible level of consumption allowing the households to survive, while Social minimum defines a model category allowing the minimum level of decent life, necessary for social integration. Between these two extremes there is a sphere of scarcity. In 2019, the minimum subsistence rate in a one-person household increased by 4.3% and the minimum subsistence rate by 3.8%, with the inflation rate of 2.3%. Under these conditions, various poverty indicators in Poland have decreased compared to 2018.
Design Patterns in Practice from the Point of View of Developers
Authors: Sousa Bruno Luan , Ferreira Mívian Marques , Bigonha Mariza Andrade da Silva , Ferreira Kecia Aline Marques
Published: July 2020

Design patterns are a relevant research topic that has been empirically investigated by academia in the last years. However, there is still a gap in the perception of the use of design patterns in practice. In this paper, we aim to bridge this gap by analyzing a real Brazilian scenario. Considering that Belo Horizonte is one of the main Brazilian cities in the context of software development, we decide to carry out a survey with 58 active developers from this city. The results exhibited in this paper bring a real perception of the use of design patterns in a relevant center of software development. In this survey, we have identified that design patterns are not widely disseminated in the local industry since 40% of the participants claimed do not frequently make use of them. We have also found that the lack of use of design patterns is mainly associated with the lack of knowledge of these solutions by the developers besides the absence of incentives from the companies. Moreover, we discussed some benefits pointed out by the participants and listed the design patterns most used and less used by the developers.
Placement of Totally Implantable Venous Access Ports Using the Single-Incision Technique: Outcomes and Complications
Authors: Jang Seo Jin , Kwon Jae Hyun , Cha Yoon Ki , Kim Do Yeun
Published: July 2020

Background: A totally implantable venous access port (TIVAP) is an essential component of care for oncology patients. Conventional placement of the TIVAP is performed through the internal jugular vein or the subclavian vein using a tunneled catheter, which involves creating two incisions. However, the conventional technique has several potential limitations. To address these limitations, a single-incision technique without a second incision or subcutaneous tunneling has been extensively tested since first being introduced by Glenn in 2007. Objectives: The purpose of this study was to evaluate the technical success, clinical outcomes, and complications of the single-incision technique for the placement of TIVAPs. Patients and Methods: Between January 2013 and June 2017, 182 TIVAPs were placed by a single-incision technique in 175 patients, including 79 men and 96 women (mean age, 62.4 years; range: 20 - 88 years). Electronic medical records were retrospectively reviewed to obtain patient data, outcomes, and complication rates. Results: A total of 40,594 catheter maintenance days (median, 221.9 days; range, 1 - 889 days) were recorded for 182 TIVAPs in 176 patients. Technical and clinical success rates were both 100%. A total of 25 complications (complication rate, 13.74%) occurred, including catheter occlusion (5.49%), catheter-related infection (5.49%), wound dehiscence (1.10%), catheter kinking (0.55%), venous thrombosis (0.55%), and extravasation during infusion (0.55%). Conclusion: The single-incision technique for TIVAP via the axillary vein was safe and efficient with high technical and clinical success rates. This new technique may be a good alternative to conventional techniques.
Paraganglia of the Gallbladder: An Underrecognized Incidental Finding and Potential Diagnostic Pitfall
Authors: Ramlal Bharat , Voytek Theresa , Ligato Saverio
Published: July 2020

Context.—

The identification of paraganglia (PG) in the gallbladder (GB) is infrequent, and easily overlooked as it is not something routinely reported. Occasionally they may be misinterpreted as neoplastic cells, such as low-grade carcinomas, germ cell tumors, or because of their close resemblance to neuroendocrine cells, as low-grade neuroendocrine neoplasms.

Objective.—

To evaluate the incidence and histological features of PG of the GB in patients that underwent cholecystectomy, and discuss the potential misinterpretation of these benign structures as clusters of neoplastic cells.

Design.—

A retrospective study of cholecystectomy specimens performed during a 6-month period were reviewed for identification of PG. Immunohistochemical studies for chromogranin, synaptophysin, S100, and cytokeratin AE1/AE3 were performed in selected cases.

Results.—

A total of 365 GBs were reviewed and in 16 cases (4.4%) PG was identified within the subserosal connective tissue of the GB wall or cystic duct adjacent to small capillaries, nerves, and ganglia. They consisted of well-demarcated, lobular structures ranging in size from 0.2 to 0.5 cm, which were predominantly composed of chief cells, with strong expression for chromogranin and synaptophysin and negative CKAE1/AE3, and a minor component of S100-positive sustentacular cells.

Conclusions.—

PG is an uncommon finding with a prevalence of 4.4% in our study. Awareness of their location, histologic features, and immunohistochemical profile may help practicing pathologists to confirm their benign nature, avoid a misdiagnosis of malignancy, and prevent unnecessary diagnostic work-up and treatment.
Breast implant-associated anaplastic large cell lymphoma in an Asian patient: The first case report from Thailand
Authors: Thienpaitoon Peera , Disphanurat Wareeporn , Warnnissorn Naree
Published: July 2020

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) has received increasing interest among plastic surgeons as a long-term complication of breast augmentation. Although the prognosis is usually good, mortality is a possible outcome. Most of the cases reported in the past two decades have been from the United States, Europe, and Australia, whereas cases of BIA-ALCL in Asia remain rare. Herein, we describe the first known case of BIA-ALCL in Thailand, in which a 32-year-old woman developed BIA-ALCL 3 years after breast augmentation using textured implants. The patient underwent bilateral removal of the implants and ipsilateral total capsulectomy. This case report—the first of its kind from Thailand—should increase awareness of BIA-ALCL among plastic surgeons in Asia. The true incidence of BIA-ALCL in Asia may be underreported.
A importância do lúdico nas aulas de educação física no processo de ensino aprendizagem nas séries iniciais
Authors: Bezerra Marcos Antonio Araújo , Silva Hellen Karen Dório da , Bezerra Gabriela Gomes de Oliveira , Simões Neto José de Caldas , Vanali Renan Costa
Published: July 2020

O lúdico no processo ensino-aprendizagem contribui significativamente no desenvolvimento físico, afetivo, social e cognitivo, auxilia na prática do professor proporcionando aos educandos uma aprendizagem de qualidade. Este artigo procurou compreender a importância do lúdico no processo de ensino aprendizagem nas aulas de Educação Física nas séries iniciais. Para isso desenvolveu uma pesquisa de revisão bibliográfica de abordagem qualitativa, tendo em vista colher opiniões, concepções e explicações fazendo uma reflexão em torno do assunto. Diante as concepções dos autores sobre o saber da criança por meio do brincar, vimos que este contribui de forma harmoniosa e significativa para o desenvolvimento das habilidades e capacidades do aluno no contexto educacional, favorecendo através da mediação do professor a criticidade e autonomia dos alunos. Relação de reciprocidade entre professor e aluno é necessário para resolver situações presentes no cotidiano escolar nas aulas de Educação Física. Considera- se com este trabalho, que é importante utilizar o lúdico na prática docente.
L’évolution de la réponse à l’intervention : d’un modèle d’identification des élèves en difficulté à un système de soutien à paliers multiples
Authors: Desrochers Alain , Guay Marie-Hélène
Published: July 2020

L’approche de la réponse à l’intervention (RàI) a d’abord été proposée pour résoudre un problème associé à l’identification des élèves qui affrontent des difficultés d’apprentissage sévères. Elle s’est graduellement transformée en une approche éducative axée sur la prévention des difficultés d’apprentissage et un système de soutien à la réussite de tous les élèves. L’objectif du présent article est de décrire les grandes étapes de cette transformation ainsi que les principales caractéristiques d’un modèle de soutien à paliers multiples. Nous explicitons également le lien entre la réponse à l’intervention et les autres articles dans ce numéro thématique, notamment la gestion de la mise en oeuvre de cette approche préventive et son élargissement à l’enseignement de la mathématique et à la régulation du comportement. Enfin, nous discutons l’apport de la réponse à l’intervention en éducation.
Le rôle du développement professionnel dans la mise en oeuvre du modèle de la réponse à l’intervention
Authors: Richard Mario
Published: July 2020

L’idée à la base du modèle de la réponse à l’intervention (RàI) apparaît relativement simple. Toutefois, de nombreuses écoles réalisent que son implantation s’avère plus complexe qu’il n’y paraît. Comme pour toutes les améliorations en éducation, l’implantation réussie repose sur un processus de développement professionnel (DP) des enseignants qui doit être soigneusement planifié et mis en oeuvre rigoureusement. Les études comparatives internationales montrent que le DP des enseignants constitue l’un des meilleurs moyens pour améliorer la qualité de l’enseignement. La réalisation d’une synthèse de recherches sur le développement professionnel nous a permis de répertorier cinq principes favorisant son efficacité. Nous expliquerons d’abord ces principes, puis nous verrons comment la Commission scolaire de la Rivière-du-Nord de St-Jérôme (Québec) a procédé à une implantation réussie du modèle RàI en lecture en mettant en place un processus de DP qui les respecte.
Récits de la mise en oeuvre de modèles de réponse à l’intervention inspirée d’un modèle d’accompagnement systémique du développement pédagogique et organisationnel
Authors: Guay Marie-Hélène , Gagnon Brigitte
Published: July 2020

Au cours des dernières années, deux commissions scolaires de la Montérégie, au Québec, ont amorcé la mise en oeuvre d’un modèle de réponse à l’intervention (RàI) pour l’apprentissage du langage oral et écrit, au préscolaire et au premier cycle du primaire, en s’inspirant d’un modèle d’accompagnement systémique du développement pédagogique et organisationnel (Guay et Gagnon, 2020a). Dans cet article, nous présentons les récits de ces deux expériences de mises en oeuvre en détaillant des outils et des dispositifs élaborés pour les appuyer. Nous faisons également état de bons coups et d’obstacles rencontrés. Ces récits visent à guider les équipes de leaders chargées de soutenir le déploiement d’un modèle de réponse à l’intervention dans une organisation scolaire.
Dissecting transcriptional amplification by MYC
Authors: Nie Zuqin , Guo Chunhua , Das Subhendu K , Chow Carson C , Batchelor Eric , Simons S Stoney , Levens David
Published: July 2020

SupraphysiologicalMYClevels are oncogenic. Originally considered a typical transcription factor recruited to E-boxes (CACGTG), another theory posits MYC a global amplifier increasing output at all active promoters. Both models rest on large-scale genome-wide ”-omics’. Because the assumptions, statistical parameter and model choice dictates the ‘-omic’ results, whether MYC is a general or specific transcription factor remains controversial. Therefore, an orthogonal series of experiments interrogated MYC’s effect on the expression of synthetic reporters. Dose-dependently, MYC increased output at minimal promoters with or without an E-box. Driving minimal promoters with exogenous (glucocorticoid receptor) or synthetic transcription factors made expression more MYC-responsive, effectively increasing MYC-amplifier gain. Mutations of conserved MYC-Box regions I and II impaired amplification, whereas MYC-box III mutations delivered higher reporter output indicating that MBIII limits over-amplification. Kinetic theory and experiments indicate that MYC activates at least two steps in the transcription-cycle to explain the non-linear amplification of transcription that is essential for global, supraphysiological transcription in cancer.